Clinical outcomes of esophageal granular cell tumors with different endoscopic resection methods

Esophageal granular cell tumors (GCTs), the second most common subepithelial tumors (SETs) of the esophagus, are potentially malignant with no definite management guidelines available. We retrospectively enrolled 35 patients with endoscopically resected esophageal GCTs between December 2008 and October 2021 and evaluated the clinical outcomes from the various methods performed. Several modified endoscopic mucosal resections (EMRs) were performed for treating esophageal GCTs. Clinical and endoscopic outcomes were evaluated. Mean age of patients was 55.8 ± 8.2, with majority being men (57.1%). Mean tumor size was 7.2 ± 2.6 mm, most (80.0%) were asymptomatic and present in the distal third of the esophagus (77.1%). Endoscopic characteristics predominantly included broad-based (85.7%) and whitish-to-yellowish color changes (97.1%). Endoscopic ultrasound (EUS) of 82.9% of the tumors revealed homogeneous hypoechoic SETs originating from the submucosa. The five endoscopic treatment methods used were: ligation-assisted (77.1%), conventional (8.7%), cap-assisted (5.7%), and underwater (5.7%) EMRs and ESD (2.9%). Mean procedure time was 6.6 ± 2.1 min, and no procedure-associated complications were noted. The en-bloc and complete histologic resection rates were 100% and 94.3%, respectively. No recurrences were noted during follow-up, and no significant differences in the clinical outcomes of the different methods of endoscopic resection were found. Based on tumor characteristics and therapeutic outcomes, modified EMR methods can be effective and safe. However, there were no significant differences in the clinical outcomes of the different methods of endoscopic resection.

Clinical and endoscopic characteristics of sessile serrated lesions with dysplasia/carcinoma

BACKGROUND/AIMS

Some sessile serrated lesions (SSLs) progress into dysplasia and colorectal cancer, however, the clinical and endoscopic characteristics of SSLs with dysplasia remain to be determined. In this study, we elucidated these characteristics in SSLs with dysplasia/carcinoma, compared with those of SSLs without dysplasia.

METHODS

We retrospectively collected the clinical, endoscopic, and pathological data of 254 SSLs from 216 patients endoscopically resected between January 2009 and December 2020.

RESULTS

All SSLs included 179 without dysplasia and 75 with dysplasia/carcinoma, including 55 with low-grade dysplasia, 10 with high-grade dysplasia, and 10 with submucosal cancer. In clinical characteristics, SSLs with dysplasia/carcinoma were significantly associated with advanced age, metabolic diseases, and high-risk adenomas. In endoscopic characteristics, SSLs with dysplasia/carcinoma were significantly associated with the distal colon, large size, polypoid morphology, surface-changes, no mucus cap, and narrow-band imaging international colorectal endoscopic classification (NICE) type 2/3. In the multivariate analysis, high-risk adenomas (odds ratio [OR], 2.98; p = 0.01), large size (OR, 1.18; p < 0.01), depression (OR, 11.74; p = 0.03), and NICE type 2/3 (OR, 14.97; p < 0.01) were significantly associated with SSLs with dysplasia/carcinoma.

CONCLUSIONS

SSLs had a higher risk of dysplasia in the distal colon than in the proximal colon. SSLs with large size, depression, and adenomatous surface-patterns, as well as those in patients with high-risk adenomas, increased the risk of dysplasia/ carcinoma. This suggests that the clinical and endoscopic characteristics can aid in the diagnosis and management of SSLs with dysplasia/carcinoma.

Approach for the Management of Indefinite-for-neoplasia Lesions Detected on Gastric Mucosal Biopsy

Indefinite-for-neoplasia is an expression used to describe lesions in which carcinoma or dysplasia cannot be clearly and conclusively established via biopsy. Gastric indefinite-for-neoplasia may represent a reactive change secondary to inflammation in some patients; however, some lesions are eventually diagnosed as dysplasia or carcinoma. Follow-up endoscopic biopsy is commonly performed in patients with gastric indefinite-for-neoplasia lesions. Nonetheless, patients may undergo resection based on a high index of clinical suspicion for dysplasia or carcinoma based on endoscopic findings. Accurate target biopsies of the lesion and effective communication with pathologists are required to improve diagnostic accuracy and avoid unnecessary re-examinations. It is important to establish endoscopic findings useful in differentiating lesions that require resection. In this review, we describe the approach for the management of indefinite-for-neoplasia lesions detected on gastric mucosal biopsy and the characteristics of lesions that require resection.

A large and pedunculated inflammatory pseudotumor with pseudosarcomatous change of the cecum mimicking a malignant polyp: a case report and literature review

Inflammatory pseudotumor (IPT) is a rare benign tumor of unknown etiology that can occur in almost any organ system. It has neoplastic features such as local recurrence, invasive growth, and vascular invasion, leading to the possibility of malignant sarcomatous changes. The clinical presentations of colonic IPT may include abdominal pain, anemia, a palpable mass, and intestinal obstruction. A few cases of colonic IPT have been reported, but colonic IPT with pedunculated morphology is very rare. Furthermore, since it can mimic malignant polyps, understanding the endoscopic findings of colonic IPT is important for proper treatment. Herein, we present a case of colonic IPT with pseudosarcomatous changes, presenting as a large polyp, mimicking a malignant polyp in the cecum, along with a literature review.

Efficacy and safety of one-step knife compared to conventional insulated-tip knife for endoscopic submucosal dissection: a preliminary study with prospective data collection and retrospective review

BACKGROUND

Endoscopic submucosal dissection (ESD) is not as tiresome as gastrectomy, but it is a time-consuming procedure. One-step knife (OSK) is a novel knife that combines a knife for ESD and an injection needle into one sheath. In this study, we aimed to compare the insulated tip type of OSK and conventional knife (CK) in terms of procedure time and complication rate.

METHODS

Medical records of patients with ESD using CK between February and September 2020 were retrospectively reviewed. Subsequently, data from patients who underwent ESD using OSK by September 2021 were prospectively collected. Total procedure time, procedure time by location and complication rate in the OSK and CK group were compared.

RESULTS

In the study period, a total of 203 patients (OSK, 102 patients; CK, 101 patients) were analyzed. On multivariate analysis, using CK, body location, resection size ≥ 40 mm, and submucosal fibrosis were associated with longer procedure time. The total procedure time was statistically significantly reduced in the OSK group (median 11 vs. 17 min, p < 0.01). The procedure time for each location was more reduced in the body (median 14 vs. 19 min p < 0.01) than the antrum (median 10 vs. 14 min, p = 0.01) in the OSK group. There was no significant difference in post-ESD bleeding and perforation in the two groups (3.9 vs. 3.9%, p = 0.99 and 1.0 vs. 2.0%, p = 0.56).

CONCLUSIONS

OSK significantly reduced the total procedure time of ESD. OSK could be an effective and safe knife for gastric ESD, especially for body lesions.

Esophageal Stricture after Endoscopic Drainage of Esophageal Abscess as a Complication of Acute Phlegmonous Esophagitis: A Case Report

Esophageal abscess caused by acute phlegmonous esophagitis is rare but life-threatening. Rapid abscess drainage is an important part of the treatment, and endoscope-assisted intra-luminal abscess drainage is frequently performed. Although endoscopic drainage is less invasive than surgery, it has the potential to cause esophageal stricture as a complication. We present a rare case of esophageal stricture as a complication of intra-luminal drainage and evaluate a method to minimize the incidence of esophageal stricture complications.

Combination conventional endoscopy and endoscopic ultrasound can differentiate between esophageal granular cell tumors and leiomyomas

Esophageal leiomyomas and granular cell tumors (GCTs) are the 2 most common subepithelial tumors found in the esophagus. We attempted to differentiate the 2 tumors using endoscopic findings and endoscopic ultrasound (EUS) features. Between December 2008 and June 2021, a total of 38 esophageal GCTs and 11 esophageal leiomyomas originating from the muscularis mucosa were selected. Clinical characteristics and endoscopic features were retrospectively reviewed. Although esophageal GCTs are mainly located in the lower third of the esophagus (81.6%), esophageal leiomyomas are mainly located in the upper third of the esophagus (45.5%). Broad-based (84.2%, P = .002) and whitish-to-yellowish color changes (97.4%, P < .001) are significant endoscopic features of esophageal GCTs. The echogenicity of esophageal leiomyoma was similar to that of proper muscle echogenicity. However, the echogenicity of esophageal GCTs was hyperechoic compared to that of the proper muscle layer (90.0% vs 9.1%, respectively, P < .001). EUS revealed a clearer hyperechoic epithelial lining in the esophageal leiomyoma than in esophageal GCTs (100% vs 26.7%, respectively, P < .001). The 5 endoscopic factors (location of the lower third, broad base, whitish-to-yellowish color, hyper-echogenic, and unclear demarcated hyperechoic epithelial line) were counted to differentiate esophageal GCTs from esophageal leiomyomas. Tumors with 3 or more endoscopic factors were all esophageal GCTs. The characteristic endoscopic and EUS features of esophageal GCTs were broad-based, whitish-to-yellowish colored subepithelial tumors located in the lower third of the esophagus and hyperechoic tumor with an unclear demarcated hyperechoic epithelial line. A combination of these features can predict esophageal GCTs before endoscopic resection.

Underwater endoscopic mucosal resection of upper gastrointestinal subepithelial tumors: A case series pilot study (with video)

INTRODUCTION

Underwater endoscopic mucosal resection (UW-EMR) has been recently introduced as an effective technique for rectal third layer subepithelial tumors. Therefore, we aimed to assess the safety, efficacy, and procedure time of UW-EMR for upper gastrointestinal subepithelial tumors (SETs) originating from the deep mucosal and/or submucosal layers.

METHODS

Between August 2018 to July 2022, a total of 17 SETs (7 duodenal SETs, 6 gastric SETs, and 4 esophageal SETs) were included in this study. On endoscopic ultrasound examinations, the tumors were found to be embedded in the submucosa without muscularis propria invasion. All SETs were resected successfully using UW-EMR. The characteristics of the tumors and their R0 resection rate, adverse event rate, and recurrence rate were evaluated retrospectively.

RESULTS

The mean tumor size was 0.9 cm (range, 0.3-1.5 cm). En bloc resection and complete resection rates were 100%, respectively. The patients showed no complications such as perforation or bleeding. Histologic assessments of the resected tumors revealed 9 neuroendocrine tumors (7 on the duodenum, 2 on the stomach), 2 gastric cystica profunda, 1 gastric follicular lymphoma, 1 gastric fibromyxoma, 3 esophageal granular cell tumors, and 1 esophageal adenoid cystic carcinoma. The mean procedural time was 3.2 min (range, 1.3-8.7 minutes). The overall en bloc and complete resection rates were 100%, respectively. No recurrence was observed during the follow-up period.

CONCLUSION

UW-EMR is a safe and effective treatment for upper gastrointestinal SETs embedded in the submucosal layer. Further studies are needed to compare other endoscopic resection techniques.

Extragastric recurrence in patients who underwent surgical resection of stage I gastric cancer: Incidence, risk factors, and value of abdominal computed tomography as a postoperative surveillance method

Extragastric recurrence after radical resection of stage I gastric cancer is very rare. We investigated the incidence of extragastric recurrence and risk factors in patients who underwent surgical resection of stage I gastric cancer and evaluated the value of abdominal CT as a surveillance tool. This retrospective study enrolled 914 patients with stage I gastric cancer who underwent surgical resection at a single tertiary hospital. We investigated extragastric recurrence during the follow-up period, and disease-free survival (DFS) was assessed. Over a median follow-up period of 39 months, the overall incidence of extragastric recurrence was 2.2% (20/914). Risk factors for extragastric recurrence included deep submucosal invasion (SM2-3), muscularis propria invasion, and lymph node metastasis (hazard ratio [HR]=10.37, 28.101, and 6.843; P = .028, .002, and .001, respectively). Based on the number of risk factors, patients were stratified into 3 subgroups: low-risk (pT1aN0, pT1b(SM1)N0, 496/914), moderate-risk (pT1aN1, pT1b(SM1)N1, pT1b(SM2-3)N0, pT2N0, 369/914), and high-risk (pT1b(SM2-3)N1, 49/914). DFS was significantly longer in the low-risk group, followed by the moderate-risk and high-risk groups. We propose that postoperative CT surveillance should be omitted for stage 1A cases involving the mucosa and SM1 because of the extreme rarity of extragastric recurrence.

Clinical outcomes of gastroduodenal neuroendocrine tumors according to their WHO grade: A single-institutional retrospective analysis

The management of gastroduodenal neuroendocrine tumor (NET) has been controversial between radical surgical resection and local excision including endoscopic resection. A gastroduodenal NET grade (G), measured by their mitotic rate and Ki67 proliferation index, is important to predict prognosis. In this study, we aimed to compare the clinical outcomes of gastroduodenal NET according to grades in order to identify poor prognostic factors of gastroduodenal NETs. Fifty-four gastroduodenal NETs diagnosed between December 2008 and December 2020 in a tertiary referral hospital were retrospectively reviewed. The clinical outcomes of gastroduodenal NETs, according to tumor grades and factors associated with NET G2-3, were analyzed. A total of 52 gastroduodenal NET patients was enrolled. The mean follow-up period was 56.2 ± 40.1 months. The mean size of gastric and duodenal NET was 7.9 ± 11.0 mm and 9.8 ± 7.6 mm, respectively. During the study period, 72.7% (16/22) of gastric NETs and 83.3% (25/30) of duodenal NETS were G1. All G1 gastroduodenal NETs showed no lymph node or distant metastasis during the study periods. All G3 gastroduodenal NETs showed metastasis (one lymph node metastasis and 3 hepatic metastases). Among metastatic NETs, the smallest tumor size was a 13 mm gastric G3 NET. Factors associated with G2-3 NETs were larger tumor size, mucosal ulceration, proper muscle or deeper invasion, and lymphovascular invasion. A small-sized gastroduodenal NET confined to submucosa without surface ulceration may be suitable for endoscopic resection. After local resection of a gastroduodenal NET (G1) without lymphovascular and muscle proper invasion, follow-up examination without radical surgical resection can be recommended. G3 NETs may be treated by radical surgical resection, regardless of tumor size.

Olmesartan-associated Enteropathy with Acute Kidney Injury

Olmesartan, a recently introduced angiotensin II receptor blocker for hypertension, has been reported to cause drug-induced small bowel enteropathy. The diagnosis of olmesartan-associated enteropathy (OAE) needs clinical suspicion and the exclusion of coeliac disease, as it mimics coeliac sprue. Once diagnosed, it can be completely cured with the discontinuation of olmesartan. However, due to the extremely low incidence of OAE in Korea, clinical suspicion and diagnosis may be a challenge. The authors report the first case of OAE presenting with chronic diarrhea and acute kidney injury in Korea.

Seven-day triple therapy is sufficient to eradicate infection caused by Helicobacter pylori without 23S rRNA point mutation

ABSTRACT

Tailored therapy based on dual priming oligonucleotide-based polymerase chain reaction (DPO-PCR) can be considered an alternative to overcome the low eradication rate in high clarithromycin-resistance areas. The triple therapy (TT) duration of the tailored approach in most studies was 7 days for patients without point mutation. However, recent western guidelines have recommended a treatment duration of 14 days. The aim of this study was to compare the success rate of 7 and 14 days of TT for eradicating Helicobacter pylori without point mutation, as determined by DPO-PCR.Between Feb 2016 and Feb 2019, medical records of patients who underwent DPO-PCR were reviewed. Patients without point mutation as determined by DPO-PCR were enrolled in this study. The eradication success rate and adverse events were evaluated.A total of 366 patients without A2142G and A2143G point mutation were enrolled. The success rates of 7-day and 14-day TT were 88.4% (168/190) and 85.9% (151/176) by intention to treat analysis (P = .453) and 90.8% (168/185) and 90.4% (151/167) by per-protocol analysis (P = .900), respectively. The adverse event rates showed no significant difference between the 2 groups.In patients without point mutation based on DPO-PCR results, 7-day TT is as effective as 14-day TT. Therefore, 7 days may be considered as a cost-effective treatment duration in Korea.

Absent or impaired rectoanal inhibitory reflex as a diagnostic factor for high-grade (grade III-V) rectal prolapse: a retrospective study

Background

Clinically diagnosing high-grade (III–V) rectal prolapse might be difficult, and the prolapse can often be overlooked. Even though defecography is the significant diagnostic tool for rectal prolapse, it is noticed that rectoanal inhibitory reflex (RAIR) can be associated with rectal prolapse. This study investigated whether RAIR can be used as a diagnostic factor for rectal prolapse.

Methods

In this retrospective study, we evaluated 107 patients who underwent both anorectal manometry and defecography between July 2012 and December 2019. Rectal prolapse was classified in accordance with the Oxford Rectal Prolapse Grading System. Patients in the high-grade (III–V) rectal prolapse (high-grade group, n = 30), and patients with no rectal prolapse or low-grade (I, II) rectal prolapse (low-grade group, n = 77) were analyzed. Clinical variables, including symptoms such as fecal incontinence, feeling of prolapse, and history were collected. Symptoms were assessed using yes/no surveys answered by the patients. The manometric results were also evaluated.

Results

Frequencies of fecal incontinence (p = 0.002) and feeling of prolapse (p < 0.001) were significantly higher in the high-grade group. The maximum resting (77.5 vs. 96 mmHg, p = 0.011) and squeezing (128.7 vs. 165 mmHg, p = 0.010) anal pressures were significantly lower in the high-grade group. The frequency of absent or impaired RAIR was significantly higher in the high-grade group (19 cases, 63% vs. 20 cases, 26%, p < 0.001). In a multivariate analysis, the feeling of prolapse (odds ratio [OR], 23.88; 95% confidence interval [CI], 4.43–128.78; p < 0.001) and absent or impaired RAIR (OR, 5.36; 95% CI, 1.91–15.04, p = 0.001) were independent factors of high-grade (III–V) rectal prolapse. In addition, the percentage of the absent or impaired RAIR significantly increased with grading increase of rectal prolapse (p < 0.001). The sensitivity of absent or impaired RAIR as a predictor of high-grade prolapse was 63.3% and specificity 74.0%.

Conclusions

Absent or impaired RAIR was a meaningful diagnostic factor of high-grade (III–V) rectal prolapse. Furthermore, the absent or impaired reflex had a positive linear trend according to the increase of rectal prolapse grading.

Usefulness and Complications of Needle Knife Fistulotomy as a Rescue Procedure in Patients with Pancreaticobiliary Disease

Background/Aims

Needle knife fistulotomy (NKF) is a technique to facilitate pancreatic and biliary duct access during ERCP. The double-guidewire technique (DGT) is also used in cases of difficult cannulation, but it can increase the incidence of post-ERCP-pancreatitis (PEP). This study examined the success and complication rates of NKF after unsuccessful standard cannulation or DGT in patients with pancreaticobiliary disease.

Methods

The data of 209 patients who received NKF as a rescue procedure between January 2009 and December 2016 were reviewed retrospectively. The cannulation success and complication rates were assessed.

Results

The overall cannulation success rate was 90.4%. The success rates of patients who received NKF after standard cannulation or DGT were similar (82.6% [142/172] and 73.0% [27/37], respectively, p=0.179). Furthermore, there was no significant difference in the incidence of procedure-related adverse events between the two groups (10.5% [18/172] and 16.2% [6/37], respectively, p=0.391). Endoscopic retrograde pancreatic drainage (ERPD) insertion decreased the incidence of PEP (0% [0/16] in ERPD and 14.6% [19/130] in non-ERPD, p=0.132) among patients who received PD cannulation.

Conclusions

NKF is an effective and safe method that can be considered for rescue management after the initial failure of standard cannulation or DGT. NKF following standard cannulation can be preferred over NKF following DGT because of the higher success rate and the lower rate of pancreatitis, but the difference was not significant. PD stenting in patients at high risk of PEP can be considered to decrease pancreatitis.

Clinical outcomes of iatrogenic upper gastrointestinal endoscopic perforation: a 10-year study

Background

Upper gastrointestinal endoscopic examination is a relatively safe procedure; however, all endoscopic procedures are invasive and are associated with a risk of iatrogenic perforation. To evaluate clinical outcomes of iatrogenic upper gastrointestinal endoscopic perforation. Factors associated with surgical management or mortality were analyzed.

Methods

Between November 2008 and November 2018, the medical records of 149,792 upper gastrointestinal endoscopic procedures were evaluated. The mechanisms of perforations were categorized as electrocoagulation-induced or blunt trauma-induced injuries. The incidence and clinical outcomes of iatrogenic perforations based on the types of procedures performed were evaluated.

Results

Iatrogenic endoscopic perforations occurred in 28 cases (0.019%). Iatrogenic perforation-related mortality occurred in 3 patients. The iatrogenic perforation rate based on the types of procedures performed was as follows: diagnostic endoscopy = 0.002%, duodenal endoscopic mucosal resection = 0.9%, esophageal endoscopic submucosal dissection = 10.7%, gastric endoscopic submucosal dissection = 0.2%, endoscopic self-expandable metal stent insertion for malignant esophageal obstruction = 0.1%, duodenoscope-induced injury = 0.02%, endoscopic sphincterotomy = 0.08%, and ampullectomy = 6.8%. All electrocoagulation-induced perforations (n = 21) were managed successfully (15 cases of endoscopic closure, 5 cases treated conservatively, and 1 case treated surgically). Three patients died among those with blunt trauma-induced perforations (n = 7). The factors associated with surgical management or mortality were old age, poor performance status (Eastern Cooperative Oncology Group score ≥ 1), advanced malignancy, and blunt trauma.

Conclusions

Most cases of electrocoagulation-induced iatrogenic perforations can be treated using endoscopic clips. If endoscopic closure fails for blunt trauma-induced perforations, prompt surgical management is mandatory.

Possible indication of endoscopic resection in undifferentiated early gastric cancer

Endoscopic resection for early gastric cancer (EGC) without lymph node metastasis may be a valuable treatment option. To date, endoscopic resection for undifferentiated EGC is being investigated. We evaluated the risk of lymph node metastasis in undifferentiated EGC by examining the preoperative endoscopic findings and operated pathologic specimen. The medical records of patients who underwent surgical resection because of undifferentiated EGC between November 2008 and December 2015 were reviewed retrospectively. The risk factors associated with lymph node metastasis and the lymph node metastasis rate in the expanded indication of undifferentiated EGC were evaluated. A total of 376 patients with undifferentiated EGC (233 signet ring cell type and 143 poorly differentiated type) were analyzed. Lymph node metastasis was found in 9.8% of the patients. Among the patients who met the expanded criteria (59 patients), only one patient had lymph node metastasis (signet ring cell type without ulceration and 15 mm in size). The risk factors associated with lymph node metastasis were lesion size >20 mm (OR 3.013), scar deformity (OR 2.248), surface depression (OR 2.360), submucosal invasion (OR 3.427), and lymphovascular invasion (OR 6.296). Before endoscopic resection of undifferentiated EGC, careful selection of patients should be considered. The undifferentiated EGC with size ≥15 mm, scar deformity, surface depression, submucosal invasion, and lymphovascular invasion should be considered surgical resection instead of endoscopic resection.

Clinical implications of fecal calprotectin and fecal immunochemical test on mucosal status in patients with ulcerative colitis

Although fecal calprotectin (Fcal) and the fecal immunochemical test (FIT) have been associated with endoscopic activity in ulcerative colitis (UC), the clinical implications of each marker depending on the mucosal status are not well known.A total of 174 results obtained from 128 patients with UC who simultaneously underwent colonoscopy and fecal tests were retrospectively evaluated from March 2015 to February 2018. The correlation and predictability of fecal markers as a surrogate marker of endoscopic activity, and the sensitivity, specificity, and predictive value of fecal tests for mucosal healing were statistically evaluated.Both fecal tests showed a statistically significant correlation with Mayo Endoscopic Subscore (MES) (Fcal: r = 0.678, P < .001 and FIT: r = 0.635, P < .001) and Ulcerative Colitis Endoscopic Index of Severity (UCEIS) (Fcal: r = 0.711, P < .001 and FIT: r = 0.657, P < .001). Fcal was statistically superior to FIT in predictive accuracy for endoscopic activity (area under the curve [AUC]: 0.863 vs 0.765 with MES, P < .001 and AUC; 0.847 vs 0.757 with UCEIS, P < .001). FIT was superior to Fcal in sensitivity for mucosal healing (98.0% vs 78.4% with MES, 94.9% vs 74.6% with UCEIS).Fcal and FIT were well correlated with endoscopic activity in UC and can be surrogate markers of mucosal inflammation. Depending on mucosal status, Fcal was more accurate in predicting the endoscopic activity in active inflammation, whereas FIT was more sensitive in predicting the achievement of mucosal healing.

Clinical outcomes of endoscopic submucosal dissection for lesions on the proximal location between remnant and entire stomach

BACKGROUND

Tumors located on the proximal stomach are associated with a longer procedure time and lower en-block resection of endoscopic submucosal dissection (ESD). Additionally, it is more difficult to perform ESD for lesions after distal gastrectomy because of the narrow inner space. We aimed to evaluate the therapeutic outcomes of ESD for lesions on the remnant stomach compared with those on the upper third of the entire stomach.

METHODS

A total of 135 patients with a neoplasm located on the proximal stomach who received ESD between Aug 2008 and Dec 2016 were enrolled. We retrospectively reviewed en-bloc resection rate, complete resection rate, and complication rate according to whether distal gastrectomy was performed. Clinical outcomes were compared among the 1:2 propensity-matched groups.

RESULTS

Between the remnant stomach and entire stomach, the en-bloc [92% (23/25) and 92.0% (46/50), respectively; P = 1.000] and complete resection [84% (21/25) and 88.0 (44/50), respectively; P = 0.723] rates were not significantly different. In patients with lesions that indicated ESD, there was no significant difference in en-bloc and complete resection rates. In a multivariable analysis, submucosal fibrosis [odds ratio (OR) 5.9, 95% confidence interval (CI) 1.1-30.7] and submucosa invasive cancer (OR 10.1, 95% CI 1.4-74.3) were independent risk factors for incomplete resection.

CONCLUSIONS

ESD is a feasible therapeutic option for lesions located on the proximal stomach regardless the operation history of distal gastrectomy. However, the complete resection rate decreases for lesions with submucosal fibrosis or the submucosa invasion.

Efficacy of preoperative colonoscopic tattooing with indocyanine green on lymph node harvest and factors associated with inadequate lymph node harvest in colorectal cancer

Objective: Adequate lymph node harvest (LNH) in colorectal cancer is closely related to survival. This study aimed to evaluate the effect of preoperative colonoscopic tattooing (PCT) with indocyanine green (ICG) on adequate LNH in colorectal cancer. Materials and methods: A total of 1079 patients who underwent surgical resection for colorectal cancer were divided into two groups: a tattooing group and a non-tattooing group. The patients were retrospectively analyzed for the number and adequacy of LNH according to tumor locations and stages. Univariate and multivariate analysis for factors associated with adequate LNH were done. Results: There was no significant difference between the two groups in the number and adequacy of LNH according to tumor locations. However, T1 colorectal cancer in the tattooing group had significantly higher adequate LNH (91.6% vs 82.1%, OR 2.370, p = .048) and T1 and N0 rectal cancer in the tattooing group also had higher adequate LNH although there was no statistical significance (100% vs 82.4%, OR 12.088, p = .095; 96.9% vs 84.8%, OR 5.570, p = .099) when compared to the non-tattooing group. Male sex and T1 stage were significantly associated with inadequate LNH in multivariate analysis (OR 0.556 (95% CI 0.340-0.909), p = .019; OR 0.555 (95% CI 0.339-0.910), p = .019, respectively). Conclusion: PCT with ICG did not improve adequate LNH in colorectal cancer but effectively improved adequate LNH in early colorectal cancer. Male sex and early cancer were risk factors for inadequate LNH in colorectal cancer, so PCT is needed for adequate LNH in these patients.

Preprocedural prediction of non-curative endoscopic submucosal dissection for early gastric cancer

Background and aim

Endoscopic submucosal dissection (ESD) has been accepted as the treatment of choice for early gastric cancer (EGC) without lymph node metastasis. However, additional surgical gastrectomy should be considered after non-curative endoscopic resection. We aimed to evaluate the predictive factors associated with non-curative endoscopic resection.

Methods

Between November 2008 and June 2015, a retrospective study was conducted in a single, tertiary, referral hospital. A total of 596 EGC lesions resected by ESD were analyzed. Non-curative endoscopic resection was defined as the occurrence of lesions associated with piecemeal resection, positive resection margins, lymphovascular invasion, or lesions that did not meet the expanded indications for ESD.

Results

The rate of non-curative endoscopic resection was 16.1%. The mean follow-up period was 35.3 ± 25.0 months. Associated predictive factors for non-curative endoscopic resection were female sex (OR, 2.470; p = 0.004), lesion size ≥ 20 mm (OR 3.714; p < 0.001), longer procedure time (OR 2.449, p = 0.002), ulceration (OR 3.538, p = 0.002), nodularity (OR 2.967, p<0.001), depression (OR 1.806, p = 0.038), undifferentiated carcinoma (OR 2.825, p = 0.031) and lesion located in the mid or upper third of stomach (OR 7.135 and OR 4.155, p<0.001, respectively). As the number of risk factors increased, the risk of non-curative ESD also increased.

Conclusions

Prior to selection of ESD, the risks associated with non-curative ESD should be considered so that appropriate treatment modalities may be selected.

Endoscopic predictive factors associated with local recurrence after gastric endoscopic submucosal dissection

OBJECTIVE

Endoscopic submucosal dissection (ESD) has been accepted as the treatment of choice for gastric epithelial neoplasia. Endoscopic characteristics of the primary lesion and post-ESD scars may be informative to predict the possibility of local recurrence.

METHODS

Between November 2008 and July 2015, a retrospective study was conducted in a single-tertiary referral hospital. Consecutive patients who underwent ESD for early gastric cancer (EGC) or high-grade dysplasia were analyzed to evaluate the incidence of local recurrence and associated endoscopic characteristics.

RESULTS

A total of 639 lesions were analyzed. The rates of en-bloc and complete resection were 98.1% and 95.5%, respectively. A total of 15 local recurrent lesions were found (2.3%). The endoscopic findings of primary lesions associated with local recurrence were a lesion size ≥20 mm (odds ratio, OR, 4.408; 95% confidence interval, CI, 1.369-14.186, p = .013) and incomplete endoscopic resection (OR 17.059, 95% CI 4.887-59.551, p < .001). During follow-up endoscopic examinations, atypical scar findings (non-flat morphology, erythematous color change and uneven surface pattern) were significant endoscopic findings to predict local recurrence. Local recurrence was absent for ESD scars with even-flat morphology without erythema.

CONCLUSION

Lesions with larger size (≥ 20 mm) and incompletely resected lesions had higher risk of local recurrence. Endoscopic forceps biopsy is unnecessary for even-flat ESD scar without erythematous changes.

Pathologic outcomes of endoscopic submucosal dissection for gastric epithelial neoplasia

Endoscopic submucosal dissection (ESD) has been widely implemented for the treatment of gastric superficial neoplasia. However, the final pathologic diagnosis after ESD may be different from that indicated by the results of endoscopic forceps biopsy. This study identified risk factors for gastric epithelial lesions so that early gastric cancer (EGC) could be diagnosed after ESD.From December 2008 to January 2017, 1541 lesions (1410 patients) diagnosed as initial adenoma or indefinite for neoplasia by endoscopic forceps biopsy were enrolled. The EGC rate and factors predicting upstaged diagnoses were analyzed retrospectively.The diagnostic discrepancy rate was 31.1%. Upstaged and downstaged diagnostic rates after ESD were 23.8% and 7.3%, respectively. The upstaged diagnosis rate for EGC was 18.8%. Gross depression (OR, 16.017) and surface redness (OR, 22.136) were significantly associated with EGC and lesions indefinite for neoplasia during the initial endoscopic forceps biopsy. Central depression (OR, 2.959), nodular surface (OR, 6.581), and surface redness (OR, 6.399) were significantly associated with EGC and lesions with low-grade dysplasia during the initial endoscopic forceps biopsy. Central depression (OR, 1.999), nodular surface (OR, 1.733), surface redness (OR 2.283), lesion location (upper third of the stomach) (OR, 3.989), and tumor size ≥10 mm (OR, 2.200) were significantly associated with EGC and lesions with high-grade dysplasia during the initial endoscopic forceps biopsy.Central depression, nodular surface, surface redness, lesion location, and tumors >10 mm were associated with EGC. Gastric epithelial lesions with these characteristics require attention before ESD.

Endoscopic submucosal dissection of gastric neoplasms using a snare tip

BACKGROUND

Endoscopic submucosal dissection (ESD) enables the complete removal of gastric lesions regardless of tumor size. ESD is typically performed using one of several available electrocautery knives and endoscopic mucosal resection (EMR) is performed using a diathermic snare. We aimed to investigate the clinical outcomes and complications in patients in whom a snare tip was used for ESD.

MATERIALS AND METHODS

We retrospectively evaluated the medical records of 30 patients who underwent removal of a gastric lesion using a snare tip by ESD or hybrid ESD (ESD with snaring). For hybrid ESD, snaring was performed after an adequate submucosal dissection. The clinical outcomes according to the endoscopic procedure performed were evaluated.

RESULTS

ESD was performed in 12 patients and hybrid ESD was performed in 26 patients. Overall en-bloc and complete resection rates were both 97.4%. There was one case where piece-meal resection was performed in the hybrid ESD group. There were no procedure related complications such as perforation or bleeding. The mean specimen size was 2.8 ± 0.6 cm in the ESD group and 2.3 ± 0.5 cm in the hybrid ESD group (p = .031). The mean procedure time did not differ between the two methods (12.8 min in ESD and 9.7 min in hybrid ESD, p = .060).

CONCLUSIONS

The snare tip can be used as an electrocautery knife to incise the mucosa and dissect the submucosa during removal of a gastric lesion.

Predictors of upstage diagnosis after endoscopic resection of gastric low-grade dysplasia

BACKGROUND

The optimal management of precursor lesions such as gastric low-grade dysplasia is crucial in order to improve gastric cancer-related mortality. However, there are no universally accepted management guidelines regarding which lesions should be resected or should be monitored by follow-up visits.

PATIENTS AND METHODS

We retrospectively analyzed data from 1006 gastric low-grade dysplasia lesions that had been resected via endoscopic submucosal dissection. We also evaluated the endoscopic risk factors associated with upstage diagnosis from low-grade dysplasia to high-grade dysplasia or gastric cancer.

RESULTS

The mean age of our patients was 63.7 ± 9.1 years and 70.3% of our study population included men. The predominant location and gross type of lesions was the lower third of the stomach (78.6%) and the elevated type (57.8%), respectively. The rates of pathological concordance, upstage, and downstage diagnosis were 85.3, 12.1, and 2.6%, respectively. Multivariate analysis, after adjusting for age and sex, showed that a lesion size ≥ 10 mm (Odds ratio [OR] 2.231; p = 0.003), erythema (OR 7.315; p < 0.001), nodularity (OR 5.589; p < 0.001), depression (OR 3.024; p = 0.002), and erosion (OR 7.680; p < 0.001) were all factors significantly associated with upstage diagnosis. Furthermore, an increasing number of risk factors was associated with an increasing frequency of upstage diagnosis; if there were no risk factors, then there was no upstage diagnosis.

CONCLUSIONS

This study identified several risk factors that were significantly associated with the upstage diagnosis of gastric low-grade dysplasia: lesion size ≥ 10 mm and a variety of surface changes (erythema, nodularity, depression, and erosion). Our data indicate that if there is no evidence of these endoscopic risk factors, then regular follow-up may be considered, according to the patient's combined comorbid conditions.

The Value of Computed Tomography in Preoperative N Staging of Early Gastric Cancer Meeting the Endoscopic Resection Criteria

This correction is being published to correct Fig. 2B in above article.

The clinical outcomes and risk factors associated with incomplete endoscopic resection of rectal carcinoid tumor

BACKGROUND AND AIM

The risk of lymph node metastasis of a small rectal carcinoid tumor (<10 mm) is known to be lower than that of tumors at other gastrointestinal sites. Although rectal carcinoid tumors can be treated by endoscopic resection, the resected specimen may be incomplete. The consequences of an incomplete resection are not well known.

METHOD

From December 2008 to November 2015, cases of rectal carcinoid tumors resected by endoscopic resection techniques such as endoscopic submucosal dissection (ESD), or endoscopic mucosal resection using band ligation device (EMR-L), or cap aspiration (EMR-C) were enrolled. The factors associated with incomplete endoscopic resection and clinical outcomes were retrospectively analyzed.

RESULTS

During the study period, a total of 134 rectal carcinoid tumors were resected by endoscopic techniques; ESD (n = 53), EMR-C (n = 65), and EMR-L (n = 16). The mean tumor size was 5.5 ± 2.4 mm. The mean follow-up period was 835 ± 501 days. The en bloc resection and complete resection rates were 100 and 85.8%, respectively. Procedure time was longer and the size of the resected tumor was larger in the ESD group than in the EMR-C or EMR-L (p < 0.001) group by the univariate analysis. A factor related to incomplete resection was central depression on the surface (OR 11.529, 95% CI 2.377-55.922, p = 0.002), as revealed by the multivariate analysis. Nineteen patients had an incomplete resection status and did not undergo additional resection treatment; none of these patients had recurrence during the study period.

CONCLUSIONS

A rectal carcinoid tumor with a central depression on the surface was associated with a higher incomplete resection rate. After an incomplete resection of small rectal carcinoid tumors, without evidence of lymphovascular invasion, a periodic follow-up examination without additional resection may be recommended.

The Value of Computed Tomography in Preoperative N Staging of Early Gastric Cancer Meeting the Endoscopic Resection Criteria

Background/Aims

This study evaluated the value of abdominal computed tomography (CT) in preoperative N staging of early gastric cancers (EGCs) within standard and expanded indications of endoscopic resection (ER) and investigated the factors affecting accuracy.

Methods

Between March 2009 and March 2016, a total of 268 patients with EGC within the standard and expanded indications of ER underwent preoperative abdominal CT and surgical gastrectomy with lymph node (LN) dissection. Preoperative N staging of CT was compared with the pathologic result.

Results

The accuracy of N staging for EGCs within the standard and expanded indications was 86.1% (235/268). There was no LN metastasis in patients with cN1 in CT staging. LN metastasis was found in 7 patients with EGCs that met the expanded ER indication and cN0 in CT staging. According to the univariate analysis, ulcers, including scars, were associated with the false positive of lymph node metastasis in abdominal CT (odds ratio 3.56; 95% confidence interval 1.56-8.15).

Conclusions

The present study suggests that the value of abdominal CT is limited for nodal staging of EGCs that meet the ER indication.

Polyp missing rate and its associated risk factors of referring hospitals for endoscopic resection of advanced colorectal neoplasia

Missed polyps are frequently observed in surveillance colonoscopy or referral resection. We evaluated the polyp missing rate and its associated risk factors in patients who were referred to a tertiary hospital for endoscopic resection of advanced colorectal neoplasia.A total of 388 patients with advanced neoplasia who underwent colonoscopy in their referring hospitals and only endoscopic resection without total colonoscopy in Pusan National University Yangsan Hospital from 2009 to 2014 and who underwent surveillance colonoscopy within 6 to 12 months were retrospectively analyzed.The per-patient missing rate for polyps, adenomas, and advanced neoplasia in referring hospital were 58.2% (226 cases), 47.2% (183 cases), and 5.7% (22 cases), respectively. The advanced neoplasia in surveillance colonoscopy comprised the following: ≥1 cm lesions (11 cases, 50%), high-grade dysplasia (4 cases, 18.2%), villous adenoma (4 cases, 18.2%), and invasive cancer (3 cases, 13.6%). Risk factors for missed adenomas in multivariate analysis were ≥60 years (P = .004), male (P <.001), and no usage of the cap-assisted colonoscopy (P = .015). Missed polyps/adenomas were most frequent in the ascending colon (P <.001).The missing rate for polyps/adenomas of referring hospitals was higher than expected. Especially, patients with old age or male, or no usage of cap-assisted colonoscopy on initial colonoscopy were at increased risk of missed adenoma. Careful complete colonoscopy during referral resection or early surveillance colonoscopy is mandatory in the patients with advanced colorectal neoplasia and unknown-quality index colonoscopy.

[A Case of Intramural Hematoma of the Esophagus Mimicking Acute Coronary Syndrome]

Intramural hematoma of the esophagus is a rare condition that can be spontaneous or secondary to trauma, toxic ingestion, or intervention. If it is the spontaneous type, it usually presents initially with epigastric pain, hematemesis or dysphagia. We present a case of intramural hematoma of the esophagus mimicking acute coronary syndrome. A 63-year-old man presented with severe acute chest pain. He has four coronary stents that were inserted five years ago, from a different hospital, and is on dual antiplatelet agents. Coronary angiography was performed immediately under the suspicion of acute coronary syndrome, and we found that there was no obvious clogging of the coronary arteries. Next, chest computed tomography was performed due to suspected aortic dissection, and the result was also negative. Four days later, endoscopy was performed and intramural hematoma covered with large ulcers was diagnosed.

Location characteristics of early gastric cancer treated with endoscopic submucosal dissection

BACKGROUND AND STUDY AIMS

The timely detection of early gastric cancer (EGC) is important in performing endoscopic submucosal dissection (ESD). We attempted to determine the location characteristics of regions where EGC is frequently detected and analyzed the EGC characteristics associated with that location.

METHODS

We retrospectively reviewed the medical records of patients with EGC treated by ESD between November 2008 and August 2016. We retrospectively investigated and analyzed 647 EGC lesions.

RESULTS

The patients' mean age was 66.7 ± 10.8 years. The patient population was predominantly male (77.1%, 499/647). A well-to-moderately differentiated carcinoma was observed in 97.2% of patients. The common site of carcinoma occurrence was the lower part of the stomach (the antrum and lower third of body, 89.6%). Among the stomach hemispheres, the lesser curvature side was the most frequent site of EGC (43.9%). The posterior side of EGC was more frequent than anterior side of EGC (20.4 vs. 15.6%, respectively). Submucosal invasive EGC was more frequent in the mid-to-upper parts of stomach than lower part of stomach (odds ratio 1.919; confidence interval 1.014-3.623; p = 0.045).

CONCLUSIONS

Most EGCs that are resectable with ESD were found in the lower part and in the lesser curvature of the stomach. The submucosal invasive EGC was more frequent in the mid-to-upper part of stomach.

Efficacy and safety of limited endoscopic sphincterotomy before self-expandable metal stent insertion for malignant biliary obstruction

AIM

To evaluate the safety and efficacy of limited endoscopic sphincterotomy (ES) before placement of self-expandable metal stent (SEMS).

METHODS

This was a retrospective analysis of 244 consecutive patients with unresectable malignant biliary obstruction, who underwent placement of SEMSs following limited ES from December 2008 to February 2015. The diagnosis of malignant biliary obstruction and assessment of patient eligibility for the study was established by a combination of clinical findings, laboratory investigations, imaging and pathological results. All patients were monitored in the hospital for at least 24 h following endoscopic retrograde cholangio pancreatography (ERCP). The incidence of immediate or early post-ERCP complications such as post-ERCP pancreatitis (PEP) and bleeding related to limited ES were considered as primary outcomes. Also, characteristics and complications according to the cancer type were classified.

RESULTS

Among the 244 patients included, the underlying diagnosis was cholangiocarcinoma in 118 patients, pancreatic cancer in 79, and non-pancreatic or non-biliary malignancies in the remaining 47 patients. Early post-ERCP complications occurred in 9 patients (3.7%), with PEP in 7 patients (2.9%; mild, 6; moderate, 1) and mild bleeding in 2 patients (0.8%). There was no significant association between the incidence of post-ERCP complications and the type of malignancy (cholangiocarcinoma vs pancreatic cancer vs others, P = 0.696) or the type of SEMS used (uncovered vs covered, P = 1.000). Patients who had more than one SEMS placed at the first instance were at a significantly higher risk of post-ERCP complications (one SEMS vs two SEMS, P = 0.031). No other factors were predictive of post-ERCP complications.

CONCLUSION

Limited ES is feasible and safe, and effectively facilitates the placement of SEMS, without any significant risk of PEP or severe bleeding.

Clinical Outcomes of Dilation Therapy for Anastomotic Esophageal Stricture

Background/Aims

Benign esophageal stricture after esophagectomy is not an infrequent complication. Anastomotic esophageal stricture requires frequent multiple dilations. We aimed to evaluate the clinical outcomes of dilation therapies using an endoscopic balloon or bougie dilator and analyzed the risk factors associated with refractory stricture.

Methods

Between January 2009 and May 2016, the medical records of 21 patients treated with endoscopic balloon dilation or bougie dilation for esophageal anastomotic strictures were retrospectively reviewed.

Results

During the study periods, a total of 21 patients were diagnosed with esophageal anastomotic stricture and included for analysis (17 male; mean age, 68.2±7.2 years at the first procedure). The mean stricture length was 6.4±8.1 mm. The refractory stricture was found in 28.6% of patients, and successful relief of dysphagia was achieved in 71.4% of patients. The major complication associated with dilations was absent. Factors associated with refractory stricture were stricture length (> 10 mm, p<0.049) and diabetes mellitus (p=0.035). Additive bougie dilations achieved clinical success in 4 out of 7 patients.

Conclusions

Dilation with endoscopic balloon or bougie dilator was an effective and safe procedure for benign anastomotic esophageal strictures of less than 10 mm in length.

Assessment of disease activity by fecal immunochemical test in ulcerative colitis

AIM

To evaluate the efficacy of quantitative fecal immunochemical test (FIT) as biomarker of disease activity in ulcerative colitis (UC).

METHODS

Between February 2013 and November 2014, a total of 82 FIT results, obtained in conjunction with colonoscopies, were retrospectivelyevaluated for 63 patients with UC. The efficacy of FIT for evaluation of disease activity was compared to colonoscopic findings. Quantitative fecal blood with automated equipment examined from collected feces. Endoscopic disease severity were assessed using the Mayo endoscopic subscore (MES) classification. The extent of disease were classified by proctitis (E1), left sided colitis (E2), and extensive colitis (E3). Clinical activity were subgrouped by remission or active.

RESULTS

All of 21 patients with MES 0 had negative FIT (< 7 ng/mL), but 22 patients with MES 2 or 3 had a mean FIT of > 134.89 ng/mL. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of negative FIT about mucosal healing were 73.33%, 81.82%, 91.49%, 51.43% and 73.17%, respectively. The sensitivity, specificity, PPV, NPV and accuracy of predictive value of positive FIT (cutoff value > 100 ng/mL) about active disease status were 45.45%, 93.33%, 71.43%, 82.35% and 26.83%, respectively. Among patients with clinical remission, FIT was negative in 31 (81.6%) of 38 cases, with a mean fecal hemoglobin concentration of 6.12 ng/mL (range, negative to 80.9 ng/mL) for this group of patients. Among patients with clinical active disease, FIT was negative in 16 (36.4%) out of 44 cases, with a mean fecal hemoglobin concentration > 167.4 ng/mL for this group of patients. FIT was positively correlated with endoscopic activity (r = 0.626, P < 0.01) and clinical activity (r = 0.496, P < 0.01). But, FIT did not correlate with the extent of disease (r = -0.047, P = 0.676)

CONCLUSION

Quantitative FIT can be a non-invasive and effective biomarker for evaluation of clinical and endoscopic activity in UC, but not predict the extent of disease.

Relapsed Brucellosis Presenting as Neurobrucellosis with Cerebral Vasculitis in a Patient Previously Diagnosed with Brucellar Spondylitis: A Case Report

Brucellosis is a multisystem disease with various clinical symptoms. Neurobrucellosis is a rare but serious manifestation of brucellosis. A 60-year-old man with a previous diagnosis of brucellar spondylitis presented with sudden onset of aphasia and numbness of the right upper extremity. Cerebral angiography showed diffuse narrowing and dilatation on the distal branches of both the anterior cerebral artery (ACA) and the left middle cerebral artery (MCA) which indicated cerebral vasculitis, and the patient's Brucella agglutinin titer was 1:1280. After combined antimicrobial and steroid therapy was started, the patient's condition improved significantly, and he was discharged after 1 month. Antimicrobial therapy was continued for 16 months on an outpatient basis, and the last Brucella agglutinin titer was 1:40. To our knowledge, this is the first case of relapsed neurobrucellosis with vasculitis in Korea to have been treated successfully.

Thrombotic Complications during Interventional Lung Assist: Case Series

Interventional lung assist (iLA) effectively reduces CO₂ retention and allows protective ventilation in cases of life-threatening hypercapnia. Despite the clinical efficacy of iLA, there are a few major limitations associated with the use of this approach, such as bleeding, thrombosis, and catheter-related limb ischemia. We presented two cases in which thrombotic complications developed during iLA. We demonstrated the two possible causes of thrombotic complications during iLA; stasis due to low blood flow and inadequate anticoagulation.

Vibrio vulnificus cytolysin induces superoxide anion-initiated apoptotic signaling pathway in human ECV304 cells

Previous studies showed that exposure to Vibrio vulnificus cytolysin (VVC) caused characteristic morphologic changes and dysfunction of vascular structures in lung. VVC showed cytotoxicity for mammalian cells in culture and acted as a vascular permeability factor. In this study, the underlying mechanisms of VVC-induced cytotoxicity was investigated on ECV304 cell, a human vascular endothelial cell line. When cells were exposed to 0.4 hemolytic units (HU) of VVC, consecutive apoptotic events were observed; the elevation of superoxide anion (O (-.)(2)), the release of cytochrome c, the activation of caspase-3, the cleavage of poly(ADP-ribose) polymerase, and the DNA fragmentation. The pretreatment with 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO), O(-.) 2) scavenger, completely abolished O(-.)(2) levels and downstream apoptotic events. Moreover, pretreatment with cyclosporin A (CsA), a mitochondrial permeability transition inhibitor, was capable of attenuating O(-.)(2)-mediated cytochrome c release and caspase-3 activation, and consequent apoptosis. Apoptosis, as demonstrated by oligonucleosomal DNA fragmentation and fluorescence microscopy, was induced 24 h after VVC treatment, which was also prevented by caspase-3 inhibitor, Ac-DEVD-CHO. Caspase-1 inhibitor, Ac-YVAD-CHO, did not protect ECV 304 cells from apoptosis. These results suggest a scenario where VVC-induced apoptosis is triggered by the generation of O(-.)(2), release of cytochrome c from mitochondria, activation of caspase-3, degradation of poly(ADP-ribose) polymerase, and DNA fragmentation. The induction of apoptosis in endothelial cells by VVC may provide a pivotal mechanism for understanding the pathophysiology of septicemia.

Effect of an extract of the root of Scutellaria baicalensis and its flavonoids on aflatoxin B1 oxidizing cytochrome P450 enzymes

The inhibition of aflatoxin B1 (AFB1) metabolism by a water extract of the root of Scutellaria baicalensis and its flavonoids was examined in liver microsomes. AFB1 is known to be metabolized to aflatoxin M1 (AFM1), aflatoxin Q1 (AFQ1), and AFB1-8,9-epoxide (AFBO). The water extract potently inhibited the production of AFM1 by cytochrome P450 (CYP)1A1/2 and slightly reduced AFBO formation by CYP1A1/2, CYP2B1, CYP2C11 and CYP3A1/2 in TCDD-treated rat liver microsomes. IC50 values for AFM1 and AFBO formation were 6.8 and 122.4 microg/ml, respectively. Wogonin showed the highest inhibitory activity towards AFM1 formation among the flavonoids isolated from the extract. On the other hand, the extract had no effects on the formation of AFBO and AFQ1 in human liver microsomes, and on the activities of CYP2B1, CYP2C11 and CYP3A1/2 which were detected by hydroxylation patterns of testosterone. These results demonstrated that the extract of the root of Scutellaria baicalensis has a specific inhibitory effect on CYP1A1/2 among CYP enzymes involved in AFB1 metabolism by rat and human microsomes.

Activation of caspase cascades in Korean mistletoe (Viscum album var. coloratum) lectin-II-induced apoptosis of human myeloleukemic U937 cells

Mistletoe lectins are of high biological activity and exert cytotoxic effects. We have previously shown that Korean mistletoe, Viscum album var. coloratum, lectin-II specifically induces apoptotic cell death in cancer cells, not normal lymphocytes. The destructive mechanism by mistletoe lectins on tumor cells was mediated by activation of c-JUN N-terminal kinase (JNK)/stress-activated protein kinase. Herein, we investigated the involvement of caspase cascade and its proteolytic cleavage effects on biosubstrates of human myeloleukemic U937 cells by D-galactoside and N-acetyl-galactosamine-specific Korean mistletoe lectin-II. Mistletoe lectin-II induced ladder pattern DNA fragmentation and activation of caspase-3, -8, and -9 of U937 cells, but not caspase-1 protease, in a time- and dose-dependent manner. Consistent with catalytic activation of protease, both poly(ADP-ribose) polymerase (PARP) and protein kinase C-delta (PKC-delta) are also cleaved in mistletoe lectin-II-treated U937 cells. An inhibitor of caspase-3-like protease, DEVD-CHO peptide, significantly inhibited mistletoe lectin-II-induced apoptosis, PARP cleavage, and fragmentation of DNA. These results provide the evidence that Korean mistletoe lectin-II induces apoptotic death of U937 cells via activation of caspase cascades.

Association of Shc, Cbl, Grb2, and Sos following treatment with 2,3,7,8-tetrachlorodibenzo-p-dioxin in primary rat hepatocytes

c-Src kinases and p21 Ras are known to be implicated in 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-mediated signal transduction. However, the effects of TCDD on the molecular interaction of adaptor complex in the protein tyrosine kinase signaling cascade have not been reported. The present study is designed to clarify whether TCDD modulates the molecular interactions of Shc, Cbl, Grb2, and Sos in primary rat hepatocytes. TCDD causes an electrophoretic mobility shift of Sos and increases Sos/Grb2 association. Tyrosine phosphorylated Shc, mainly p52, unloads to the Grb2/Sos complex upon TCDD stimulation. Interestingly, TCDD decreases the tyrosine phosphorylation level of Cbl, although Cbl recruits more Grb2 and Shc proteins by TCDD. These results indicate that TCDD modulates the molecular interaction of adaptor complex proteins including Shc, Grb2, Sos, and Cbl. Furthermore, tyrosine phosphorylation of Cbl may not be critical for interaction of the protein with Grb2 and Shc in the TCDD signaling pathway in primary rat hepatocytes.