Background/Aims: We investigated how interactions between humans and computer-aided detection (CADe) systems are influenced by the user’s experience and polyp characteristics. Methods: We developed a CADe system using YOLOv4, trained on 16,996 polyp images from 1,914 patients and 1,800 synthesized sessile serrated lesion (SSL) images. The performance of polyp detection with CADe assistance was evaluated using a computerized test module. Eighteen participants were grouped by colonoscopy experience (nurses, fellows, and experts). The value added by CADe based on the histopathology and detection difficulty of polyps were analyzed. Results: The area under the curve for CADe was 0.87 (95% confidence interval [CI], 0.83 to 0.91). CADe assistance increased overall polyp detection accuracy from 69.7% to 77.7% (odds ratio [OR], 1.88; 95% CI, 1.69 to 2.09). However, accuracy decreased when CADe inaccurately detected a polyp (OR, 0.72; 95% CI, 0.58 to 0.87). The impact of CADe assistance was most and least prominent in the nurses (OR, 1.97; 95% CI, 1.71 to 2.27) and the experts (OR, 1.42; 95% CI, 1.15 to 1.74), respectively. Participants demonstrated better sensitivity with CADe assistance, achieving 81.7% for adenomas and 92.4% for easy-to-detect polyps, surpassing the standalone CADe performance of 79.7% and 89.8%, respectively. For SSLs and difficult-to-detect polyps, participants' sensitivities with CADe assistance (66.5% and 71.5%, respectively) were below those of standalone CADe (81.1% and 74.4%). Compared to the other two groups (56.1% and 61.7%), the expert group showed sensitivity closest to that of standalone CADe in detecting SSLs (79.7% vs 81.1%, respectively). Conclusions CADe assistance boosts polyp detection significantly, but its effectiveness depends on the user’s experience, particularly for challenging lesions.

BACKGROUND: Rheumatoid arthritis (RA) is characterized by chronic inflammation and joint damage. Methotrexate (MTX), a commonly used disease-modifying anti-rheumatic drug (DMARD) used in RA treatment. However, the continued use of DMARDs can cause adverse effects and result in limited therapeutic efficacy. Cartilage extracellular matrix (CECM) has anti-inflammatory and anti-vascular effects and promotes stem cell migration, adhesion, and differentiation into cartilage cells. METHODS: CECM was assessed the dsDNA, glycosaminoglycan, collagen contents and FT-IR spectrum of CECM.Furthermore, we determined the effects of CECM and MTX on cytocompatibility in the SW 982 cells and RAW 264.7 cells. The anti-inflammatory effects of CECM and MTX were assessed using macrophage cells. Finally, we examined the in vivo effects of CECM in combination with MTX on anti-inflammation control and cartilage degradation in collageninduced arthritis model. Anti-inflammation control and cartilage degradation were assessed by measuring the serum levels of RA-related cytokines and histology. RESULTS: CECM in combination with MTX had no effect on SW 982, effectively suppressing only RAW 264.7 activity.Moreover, anti-inflammatory effects were enhanced when low-dose MTX was combined with CECM. In a collageninduced arthritis model, low-dose MTX combined with CECM remarkably reduced RA-related and pro-inflammatory cytokine levels in the blood. Additionally, low-dose MTX combined with CECM exerted the best cartilage-preservation effects compared to those observed in the other therapy groups. CONCLUSION Using CECM as an adjuvant in RA treatment can augment the therapeutic effects of MTX, reduce existing drug adverse effects, and promote joint tissue regeneration.

In this study, the Ti6Al4V specimens were fabricated using selective laser melting (SLM) method (Ti6Al4V-AS group). These specimens were performed to heat treatment at 950℃ and 550℃ using vacuum electric furnace (Ti6Al4V-HT group). The mechanical properties, metallographic shape, crystalline structure, and chemical compositions of the alloy specimens before and after heat treatment were analyzed. The Ti6Al4V-AS group showed ultimate tensile strength (UTS) and low elongation values. Acicular crystal grains were observed in metallographic image and the α'-Ti phase was dominant. After heat treatment (Ti6Al4V-HT group), the UTS was lowered and the elongation was increased. In addition, a lamellar structure in which columnar crystal grains are arranged was observed, α+β-Ti phase was formed, and crystallinity increased. As a result of analyzing the chemical composition, the Ti6Al4V-AS specimen contained a higher carbon content than the Ti6Al4V-HT specimen. This high carbon content could be related to the formation of α'-phase, high strength and low elongation of the Ti6Al4V-AS specimen. Ti6Al4V-HT specimen showed that the overall carbon content was low, but the carbon content was locally high in the α-Ti phase region. Therefore, it is necessary to control effectively the incorporation of carbon gas in the production of Ti6Al4V specimens using SLM.

Objective: This study analyzed the characteristics of people who attempted suicide that resulted in deaths as compared to that of the suicide survivors. Methods: This study included 799 suicide attempts that occurred from March 1, 2015, to March 31, 2019 at the emergency department of the university hospital in a city of around 300,000 people. Suicide attempts were classified into the survivor and death groups, and the characteristics of each group were compared. The suicide deaths due to re-attempts were also analyzed. Results: There were more males than females in the death groups. There was a high proportion of people aged 50 or older in the death groups. Hanging, carbon monoxide poisoning, and jumping from great heights were the most commonly used methods of suicide in the death groups. In the selected death group, psychiatric symptom, physical illness, and economic problem among the suicidal causes and depressive disorder among the psychiatric diagnoses were factors that increase the risk of suicide death. Sixty-three point four percent of the survival groups and 52.5% of the selected deaths had not received psychiatric care. On the analysis of suicide deaths due to re-attempts, the average number of suicide attempts was 2.45±0.9. The time from the first suicide attempt to the last suicide attempt was 13.8±10.4 months. Conclusion If it is necessary to make a treatment decision for a suicide attempt in a limited time, such as the case of treating a suicide attempter who visits an emergency department, it is necessary to consider the characteristic factors of the death attempts of suicidal people.

Most cystic lesions of the liver are found incidentally in imaging studies because they are not symptomatic, and generally do not require treatment. Rarely, however, symptomatic hepatic cysts may develop complications and require treatment. Here, we describe a case of a 77-year-old woman who developed biliary obstruction with abdominal pain due to compression of the bile duct by a simple hepatic cyst. We confirmed the diagnosis based on symptoms and imaging studies. The patient's symptoms improved after simple cyst ablation by sclerotherapy.
Abdominal Pain ; Aged ; Bile Ducts ; Cholestasis ; Diagnosis ; Female ; Humans ; Liver* ; Sclerotherapy

BACKGROUND/AIMS: The meaning of specialized intestinal metaplasia (SIM) in the diagnosis of Barrett's esophagus (BE) is not clear. This study was designed to determine the clinical significance of SIM in the diagnosis of Barrett's esophagus. MATERIALS AND METHODS: Biopsies were taken from 601 subjects with endoscopically suspected columnar-lined esophagus. Under light microscopy with Alcian-blue stain, SIM was identified. Demographic characteristics, gastroesophageal (GE) reflux symptoms and endoscopic findings were compared between the SIM-present group and the SIM-absent group. RESULTS: Among 601 subjects, 184 (30.6%) were confirmed by pathology to have SIM. Age over 40 years (P<0.001) and a medication history of proton pump inhibitor or H2 blocker were found more frequently in the SIM-present group (P=0.01) than in the SIM-absent group. Any of 7 GE reflux symptoms (heartburn, acid regurgitation, chest pain, hoarseness, globus sensation, cough and epigastric soreness) were more frequent in the SIM-present group than SIM-absent group (P<0.001). Specifically, heartburn, chest pain and cough were significantly more common in the SIM-present group. There was no clinically significant difference associated with endoscopic findings or other clinical characteristics. CONCLUSIONS: When subjects with endoscopically suspected BE are analyzed based on the presence or absence of SIM, the SIM-present group was significantly associated with GE reflux symptoms suggestive of frequent GE reflux. However, the presence of SIM did not correlate with endoscopic findings.
Barrett Esophagus ; Biopsy ; Chest Pain ; Cough ; Esophagus ; Gastroesophageal Reflux ; Heartburn ; Hoarseness ; Light ; Metaplasia ; Microscopy ; Prospective Studies ; Proton Pumps ; Sensation

BACKGROUND/AIMS: Chronic gastritis is a common finding during endoscopy and it is very important to describe it correctly. This study was designed to evaluate the distribution of endoscopic gastritis and the differences according to age, sex or area. MATERIALS AND METHODS: A clinical analysis was conducted on 25,536 subjects who had undergone an upper endoscopy for routine health check-up. Endoscopic gastritis was classified into four types, superficial gastritis, erosive gastritis, atrophic gastritis and intestinal metaplasia. The distribution of the four types of gastritis was evaluated according to sex, age and area. RESULTS: 51.6% of the patients had experienced at least one of the symptoms (epigastric pain or discomfort, soarness, dyspepsia, abdominal pain) on at least a few occasions during the previous year. The incidence of normal gastric finding was 3,593 (14.1%). 21,943 (85.9%) subjects have at least more than one of endoscopic gastritis. The number of cases with superficial gastritis was 7,983 (31.3%), erosive gastritis 6,054 (23.7%), atrophic gastritis 6,918 (27.1%), and intestinal metaplasia 1,181 (7.1%). Erosive gastritis, atrophic gastritis and intestinal metaplasia were more frequent in men than women (P<0.001) and in the older age group (> or =60 years) than younger age group (P<0.001). CONCLUSIONS: The prevalence of endoscopic gastritis was very common, 85.9%. In addition, erosive gastritis, atrophic gastritis and intestinal metaplasia were more frequent in men and in the older age group, which is similar to gastric cancer or peptic ulcer. Cautious regular endoscopic follow-up might be necessary regardless of gastrointestinal symptoms in Korea.
Dyspepsia ; Endoscopy ; Female ; Gastritis ; Gastritis, Atrophic ; Helicobacter pylori ; Humans ; Incidence ; Korea ; Male ; Metaplasia ; Peptic Ulcer ; Prevalence ; Stomach Neoplasms

BACKGROUND/AIMS: Chronic gastritis is a common finding during endoscopy and it is very important to describe it correctly. This study was designed to evaluate the distribution of endoscopic gastritis and the differences according to age, sex or area. MATERIALS AND METHODS: A clinical analysis was conducted on 25,536 subjects who had undergone an upper endoscopy for routine health check-up. Endoscopic gastritis was classified into four types, superficial gastritis, erosive gastritis, atrophic gastritis and intestinal metaplasia. The distribution of the four types of gastritis was evaluated according to sex, age and area. RESULTS: 51.6% of the patients had experienced at least one of the symptoms (epigastric pain or discomfort, soarness, dyspepsia, abdominal pain) on at least a few occasions during the previous year. The incidence of normal gastric finding was 3,593 (14.1%). 21,943 (85.9%) subjects have at least more than one of endoscopic gastritis. The number of cases with superficial gastritis was 7,983 (31.3%), erosive gastritis 6,054 (23.7%), atrophic gastritis 6,918 (27.1%), and intestinal metaplasia 1,181 (7.1%). Erosive gastritis, atrophic gastritis and intestinal metaplasia were more frequent in men than women (P<0.001) and in the older age group (> or =60 years) than younger age group (P<0.001). CONCLUSIONS: The prevalence of endoscopic gastritis was very common, 85.9%. In addition, erosive gastritis, atrophic gastritis and intestinal metaplasia were more frequent in men and in the older age group, which is similar to gastric cancer or peptic ulcer. Cautious regular endoscopic follow-up might be necessary regardless of gastrointestinal symptoms in Korea.
Dyspepsia ; Endoscopy ; Female ; Gastritis ; Gastritis, Atrophic ; Helicobacter pylori ; Humans ; Incidence ; Korea ; Male ; Metaplasia ; Peptic Ulcer ; Prevalence ; Stomach Neoplasms

OBJECTIVES: The purpose of this study was to compare the microshear bond strength (microSBS) and bonding interfaces of two-step total-etching and self-etching adhesive systems to three etch types of dentin either the acid etched, laser etched or laser and acid etched. MATERIALS AND METHODS: The occlusal dentinal surfaces of thirty human molars were used. They were divided into six groups: group 1, 37% H3PO4 + Single Bond 2 (3M ESPE); group 2, Er:YAG laser (KEY Laser 3, KaVo) + Single Bond 2; group 3, Er:YAG laser + 37% H3PO4 + Single Bond 2; group 4, Clearfil SE Primer + Bond (Kuraray); group 5, Er:YAG laser + Clearfil SE Bond; group 6, Er:YAG laser + Clearfil SE Primer + Bond. The samples were subjected to microSBS testing 24 hr after bonding. Also scanning microscopic evaluations were made on the resin-dentin interfaces of six specimens. RESULTS: The microSBS of group 2 was significantly lower than that of groups 1 and 3 in Single Bond 2 (p < 0.05). There were significant differences among the uSBS of groups 4, 5, and 6 in Clearfil SE Bond (p < 0.05). Very short and slender resin tags were observed in groups 2 and 5. Long and slender resin tags and lateral branches of tags were observed in groups 3 and 6. CONCLUSIONS: Treatment of dentin surface using phosphoric acid or self-etching primer improved the adhesion of Er:YAG lased dentin.
Adhesives ; Bisphenol A-Glycidyl Methacrylate ; Dentin ; Humans ; Molar ; Phosphoric Acids ; Resin Cements

BACKGROUND/AIMS: For the endoscopic treatment of benign biliary strictures (BBS), it has been a drawback to use plastic stents or uncovered self-expandable metal stents. We investigated the efficacy and safety of temporary placing fully covered self-expandable metal stents (FCSEMS) in BBS. METHODS: We enrolled 12 cases that followed up more than 6 months after insertion of a FCSEMS in BBS via ERCP. The cohort consisted of 9 patients with recurrent cholangitis, 2 patients with postcholecystectomy and 1 patient with chronic pancreatitis. The efficacy was assessed according to the resolution of strictures and also the restricture after stent removal, and the safety was evaluated according to the complications associated with stent placement. Finally, the removability of FCSEMSs was assessed. RESULTS: The median time of FCSEMS placement was 6.0 months. Resolution of the BBS was confirmed in 8 cases (67%) after a median post-removal follow-up of 8.5 months. Restricture after stent removal happened in 4 cases (33%). The complications were severe abdominal pain (n=2), pancreatic abscess (n=1) and stent migration (n=6). In 7 cases, all the FCSEMSs were successfully removed by grasping them with forceps. CONCLUSIONS: Temporary placement of a FCSEMS in BBS showed good therapeutic effects, relative safety and easy removability. Further evaluation is needed for determining the causes of restricture and for developing a new stent with antimigration features.
Abdominal Pain ; Abscess ; Cholangiopancreatography, Endoscopic Retrograde ; Cholangitis ; Cohort Studies ; Constriction, Pathologic ; Follow-Up Studies ; Hand Strength ; Humans ; Pancreatitis, Chronic ; Plastics ; Stents