Lipoproteins are key immunostimulatory components of Bacillus species for dendritic cell maturation and activation

Dendritic cells (DCs) play an important role in immunity by sensing and responding to invasive microbes. Bacillus species are rod-shaped sporulating bacteria that include the pathogenic Bacillus cereus and commensal Bacillus subtilis. Although the interaction between DC and these two Bacillus species has been studied, their key structural component that prompts DC activation is poorly understood. Here, we investigated the two Bacillus species in DC activation by whole cells and their representative microbe-associated molecular patterns (MAMPs). MAMPs including lipoteichoic acid (LTA), lipoprotein (LPP), and peptidoglycan (PGN) were purified from the two Bacillus species. Among the MAMPs, LPP from both species most potently induced the maturation and activation of DCs while PGN, but not LTA, moderately stimulated DCs. LPPs from both Bacillus species enhanced the expression of DC maturation markers including CCR7, CD40, CD80, CD83, CD86, CD205, MHC-I, and MHC-II. Among the MAMPs from B. cereus, PGN most considerably lowered the endocytic capacity of DCs implying DC maturation whereas PGN from B. subtilis lowered it to a similar degree to its LPP. Furthermore, DCs sensitized with LPPs from both Bacillus species and PGN from B. subtilis moderately induced TNF-α and IL-6 production. Notably, a combination of MAMPs did not show any synergistic effect on DC activation. Taken together, our results demonstrate that LPP is the key structural component in B. cereus and B. subtilis that leads to DC activation.

A novel defined TLR3 agonist as an effective vaccine adjuvant

Synthetic double-stranded RNA analogs recognized by Toll-like receptor 3 (TLR3) are an attractive adjuvant candidate for vaccines, especially against intracellular pathogens or tumors, because of their ability to enhance T cell and antibody responses. Although poly(I:C) is a representative dsRNA with potent adjuvanticity, its clinical application has been limited due to heterogeneous molecular size, inconsistent activity, poor stability, and toxicity. To overcome these limitations, we developed a novel dsRNA-based TLR3 agonist named NexaVant (NVT) by using PCR-coupled bidirectional in vitro transcription. Agarose gel electrophoresis and reverse phase-HPLC analysis demonstrated that NVT is a single 275-kDa homogeneous molecule. NVT appears to be stable since its appearance, concentration, and molecular size were unaffected under 6 months of accelerated storage conditions. Moreover, preclinical evaluation of toxicity under good laboratory practices showed that NVT is a safe substance without any signs of serious toxicity. NVT stimulated TLR3 and increased the expression of viral nucleic acid sensors TLR3, MDA-5, and RIG-1. When intramuscularly injected into C57BL/6 mice, ovalbumin (OVA) plus NVT highly increased the migration of dendritic cells (DCs), macrophages, and neutrophils into inguinal lymph node (iLN) compared with OVA alone. In addition, NVT substantially induced the phenotypic markers of DC maturation and activation including MHC-II, CD40, CD80, and CD86 together with IFN-β production. Furthermore, NVT exhibited an appropriate adjuvanticity because it elevated OVA-specific IgG, in particular, higher levels of IgG2c (Th1-type) but lower IgG1 (Th2-type). Concomitantly, NVT increased the levels of Th1-type T cells such as IFN-γ⁺CD4⁺ and IFN-γ⁺CD8⁺ cells in response to OVA stimulation. Collectively, we suggest that NVT with appropriate safety and effectiveness is a novel and promising adjuvant for vaccines, especially those requiring T cell mediated immunity such as viral and cancer vaccines.

Randomised clinical trial: comparison of tegoprazan and lansoprazole as maintenance therapy for healed mild erosive oesophagitis

BACKGROUND

Tegoprazan is a novel potassium-competitive acid blocker used to treat acid-related disorders.

AIM

To compare tegoprazan 25 mg with lansoprazole 15 mg as maintenance therapy in healed erosive oesophagitis (EE) METHODS: In this phase 3, double-blind, multi-centre study, patients with endoscopically confirmed healed EE were randomised 1:1 to receive tegoprazan 25 mg or lansoprazole 15 mg once daily for up to 24 weeks. The primary efficacy endpoint was the endoscopic remission rate after 24 weeks. The secondary efficacy endpoint was the endoscopic remission rate after 12 weeks. Safety endpoints included adverse events, clinical laboratory results and serum gastrin and pepsinogen I/II levels.

RESULTS

We randomised patients to tegoprazan 25 mg (n = 174) or lansoprazole 15 mg (n = 177). Most had mild EE (Los Angeles (LA) grade A: 57.3%, LA grade B: 37.3%). The endoscopic remission rate after 24 weeks was 90.6% with tegoprazan and 89.5% with lansoprazole. Tegoprazan was not inferior to lansoprazole for maintaining endoscopic remission at 24 weeks and 12 weeks. In subgroup analysis, tegoprazan 25 mg showed no significant difference in maintenance rate according to LA grade (p = 0.47). The maintenance effect of tegoprazan was consistent in CYP2C19 extensive metabolisers (p = 0.76). Increases in serum gastrin were not higher in tegoprazan-treated than lansoprazole-treated patients.

CONCLUSIONS

Tegoprazan 25 mg was non-inferior to lansoprazole 15 mg in maintenance of healing of mild EE. In this study, tegoprazan had a similar safety profile to lansoprazole.

Clinical feasibility of curative surgery after nab-paclitaxel plus gemcitabine-cisplatin chemotherapy in patients with locally advanced cholangiocarcinoma

387

Background: In a recent phase II trial, nab-paclitaxel plus gemcitabine-cisplatin (Gem/Cis/nab-P) demonstrated prolonged survival and unprecedentedly high response rate in patients with advanced cholangiocarcinoma following treatment. We aimed to evaluate the clinical feasibility of this triplet chemotherapy as induction chemotherapy in patients with locally advanced cholangiocarcinoma. Methods: We retrospectively reviewed patients with locally advanced cholangiocarcinoma who were treated with Gem/Cis/nab-P between October 2019 to December 2020. Resectability after induction chemotherapy was evaluated by a multidisciplinary team. Treatment response and surgical pathology were reviewed. Results: Of the 85 patients were included in this study. 46 (54.1%) had measurable lesions. The objective response rate (ORR) and disease control rate in patients with measurable disease were 51.1% and 85.1%, respectively. Fifty-two (61.2%) patients were determined as resectable. Four patients that were judged to be resectable did not undergo surgery due to patient refusal or poor performance status after chemotherapy. Finally, 48 out of 85 patients (56.5%) underwent subsequent curative surgery after induction chemotherapy. There were six complete remission cases (12.5%) in the final pathology, which all reported patients with extrahepatic cholangiocarcinoma. R0 resection was achieved in 46 out of the 48 patients (95.8%). Despite the initial locally advanced cholangiocarcinoma, a pathologic T stage of less than T2 was reported in 44 (95.7%) patients. Lymph node metastasis was confirmed in 13 (27.1%) patients. The overall survival rates in patients who had chemotherapy followed by surgery was better than in those treated with chemotherapy alone ( P = 0.009). Conclusions: Gem/Cis/nab-P as induction chemotherapy showed promising efficacy and clinical feasibility before curative surgery in patients with locally advanced cholangiocarcinoma. This study showed that triplet chemotherapy using Gem/Cis/nab-P has a clear down-staging effect through a high response rate in patients with cholangiocarcinoma

Preventive effect of biodegradable stents on biliary stricture and fibrosis after biliary anastomosis in a porcine model

Purpose

The current drain tubes for preventing surgically biliary anastomotic stricture are not naturally and easily removed. If a drain tube using biodegradable material is easily available and the degradation time of the tube is well controlled, surgical anastomotic stricture and fibrosis could be prevented. The aim of this animal study was to evaluate the preventive effect of novel biodegradable stents (BS) on biliary stricture and fibrosis after duct-to-duct (DD) biliary anastomosis.

Methods

Ten mini-pigs were allocated to the control group (n = 5) and or the stent group (n = 5). The common bile duct was exposed through surgical laparotomy and then resected transversely. In the stent group, a 4-mm or 6-mm polydioxanone/magnesium sheath-core BS was inserted according to the width of the bile duct, followed by DD biliary anastomosis. In the control group, DD biliary anastomosis was performed without BS insertion.

Results

In the stent group, stents were observed without deformity for up to 4 weeks in all animals. Eight weeks later, histopathologic examination revealed that the common bile duct of the anastomosis site was relatively narrower in circumference in the control group compared to the stent group. The degree of fibrosis in the control group was more marked than in the stent group (3.84 mm vs. 0.68 mm, respectively; P < 0.05).

Conclusion

Our study showed that novel BS maintained their original shape and radial force for an adequate time and then disappeared without adverse events. The BS could prevent postoperative complications and strictures after DD biliary anastomosis.

Mechanical properties and degradation process of biliary self-expandable biodegradable stents

OBJECTIVES

The clinical outcomes and prevalence of adverse events associated with biliary biodegradable stents (BS) can differ according to degradation process and time. The aim of this study was to observe the degradation process and time of different BS prototypes, and to evaluate sequential changes in their mechanical properties.

METHODS

Using an in vitro bile flow phantom model, we compared degradation time, radial force changes, and morphologic changes among four different BS prototypes: polydioxanone (PDO) BS, polyglycolide (PGA) BS, polydioxanone/poly-l-lactic acid (PDO/PLLA) sheath-core BS, and polydioxaone/magnesium (PDO/Mg) sheath-core BS. Using an in vivo swine bile duct dilation model, we performed a direct peroral cholangioscopy (DPOC) examination to observe the biodegradation process and related adverse events at regular intervals.

RESULTS

In the bile flow phantom model, the PGA BS and PDO/Mg BS prototypes showed rapid radial force reduction and morphological changes and complete degradation within six weeks. PDO/PLLA BS maintained high radial force and kept their original shape for longer than the PDO BS, up to 16 weeks. A total of 24 BS were inserted into the dilated bile ducts of 12 swine. In this animal model, DPOC examination revealed that PDO BS and PDO/PLLA BS maintained their original shapes for approximately 12 weeks, but PDO BS showed a greater degree of fragmentation and induced biliary stones and bile duct obstruction.

CONCLUSION

Our results showed that PDO/PLLA BS maintained their original shape and radial force for a relatively long time and minimized adverse events.

Real-world efficacy and safety of nab-paclitaxel plus gemcitabine-cisplatin in patients with advanced biliary tract cancers: a multicenter retrospective analysis

Background

A recent phase II trial reported prolonged survival in patients with advanced biliary tract cancer (BTC) following treatment with nab-paclitaxel plus gemcitabine-cisplatin (Gem/Cis/nab-P). We aimed to evaluate the clinical outcomes of Gem/Cis/nab-P in Asian patients with advanced BTC in a real-world setting.

Methods

We reviewed the data of patients who received Gem/Cis/nab-P for the management of advanced BTC between September 2019 and April 2021 at four institutes in Korea. Patients were classified into the Gem/Cis/nab-P and nab-P addition groups depending on the starting point of nab-P administration.

Results

A total of 178 patients treated with Gem/Cis/nab-P were included in the study. Of these, 43.8% had intrahepatic cholangiocarcinoma (CCA), 34.8% had extrahepatic CCA, and 21.3% had gall bladder cancer. A total of 117 (65.7%) patients received Gem/Cis/nab-P as the first-line treatment, while 61 (34.3%) were treated with gemcitabine-cisplatin-based chemotherapy followed by nab-P addition. The objective response rate (ORR) and disease control rate in all patients were 42.1% and 84.8%, respectively. The ORR in the Gem/Cis/nab-P group was 47.9%, while that in the nab-P addition group was 31.1%. The median progression-free survival and overall survival were 8.5 months [95% confidence interval (CI), 6.9-10.1] and 14.6 months (95% CI, 10.2-19.0), respectively. In patients who received Gem/Cis/nab-P as initial treatment, the median PFS was 9.4 months (95% CI, 7.9-10.9) and the median OS was not-reached (95% CI, not available). Anemia (n = 42, 23.6%), neutropenia (n = 40, 22.5%), and thrombocytopenia (n = 16, 9.0%) were the most common grade 3-4 toxicities. A total of 20 patients (11.2%) had conversions from unresectable to resectable disease and underwent surgery with curative intent.

Conclusion

Gem/Cis/nab-P showed favorable real-life efficacy and safety outcomes in Korean patients with advanced BTC, which was consistent with the phase II trial outcomes.

Randomised clinical trial: comparison of tegoprazan and placebo in non-erosive reflux disease

BACKGROUND

Tegoprazan is a novel, fast- and long-acting potassium-competitive acid blocker that suppresses gastric acid secretion, which could benefit patients with non-erosive reflux disease (NERD), a type of gastroesophageal reflux disease.

AIM

To evaluate the efficacy and safety profiles of tegoprazan compared with those of a placebo in Korean patients with NERD.

METHODS

In this phase 3, double-blind, placebo-controlled, multicentre study, 324 Korean patients with NERD were randomised into three treatment groups: tegoprazan 50 mg, tegoprazan 100 mg and placebo. These drugs were provided once daily for 4 weeks. The primary endpoint was the proportion of patients with complete resolution of major symptoms (both heartburn and regurgitation) for the last 7 days of the 4-week treatment period. Other outcomes related to efficacy, safety and tolerability were also evaluated.

RESULTS

Among all, 42.5% (45/106), 48.5% (48/99) and 24.2% (24/99) of patients showed complete resolution of major symptoms at week 4 after receiving tegoprazan 50 mg, tegoprazan 100 mg, and placebo, respectively. Both doses of tegoprazan showed superior efficacy than the placebo (P = 0.0058 and P = 0.0004, respectively). The complete resolution rates of heartburn and proportions of heartburn-free days (as other efficacy outcomes) were significantly higher in both tegoprazan groups than in the placebo group (P < 0.05 for all). No significant difference in the incidence of treatment-emergent adverse events were noted.

CONCLUSIONS

Tegoprazan 50 and 100 mg showed superior therapeutic efficacy compared with the placebo, as well as a favourable safety profile in patients with NERD. Registration number: ClinicalTrials.gov identifier NCT02556021.

Efficacy of S-pantoprazole 10 mg in the Symptom Control of Non-erosive Reflux Disease: A Phase III Placebo-controlled Trial

Background/Aims

S-isomer (S) pantoprazole is more bioavailable and less dependent on cytochrome 2C19 than is racemic pantoprazole. We aim to evaluate the efficacy and safety of 10 mg S-pantoprazole for treatment of non-erosive reflux disease (NERD).

Methods

In this phase 3, double-blind, randomized placebo controlled, multicenter study, 174 NERD patients were randomized to one of both treatment groups 10 mg S-pantoprazole, or placebo once daily for 4 weeks. Symptoms and safety were assessed. The efficacy endpoints were complete relief of symptoms, > 50% improvement of all reflux symptoms and recurrence.

Results

Eighty-eight patients were assigned to the S-pantoprazole group (25 males, mean 43.7 years old) and 86 to the placebo group (32 males, mean 43.0 years old), and 163 patients were subjected to full Analysis Set. A higher proportion of patients in the S-pantoprazole group had complete symptom relief (42.0 % [34/81] vs 17.1% [14/82], P < 0.001) and > 50% symptom responses (66.0% vs 50.0%, P = 0.010 for heartburn; 64.2% vs 28.0%, P = 0.010 for acid regurgitation; and 51.9% vs 30.5%, P = 0.03 for epigastric discomfort) compared to the placebo group. The factors associated with poor responsiveness to PPI were older age, female, greater body mass index, and severe baseline symptoms.

Conclusions

Low dose of S-pantoprazole (10 mg) for 4 weeks was more efficacious than placebo in providing reflux symptom relief in patients with NERD, especially acid regurgitation. More doses or longer periods of treatment with S-pantoprazole would be needed to completely eliminate symptoms.

Efficacy and Safety of Rebamipide versus Its New Formulation, AD-203, in Patients with Erosive Gastritis: A Randomized, Double- Blind, Active Control, Noninferiority, Multicenter, Phase 3 Study

Background/Aims

The mucoprotective drug rebamipide is used to treat gastritis and peptic ulcers. We compared the efficacy of Mucosta^Ⓡ (rebamipide 100 mg) and its new formulation, AD-203 (rebamipide 150 mg), in treating erosive gastritis.

Methods

This double-blind, active control, noninferiority, multicenter, phase 3 clinical trial randomly assigned 475 patients with endoscopically proven erosive gastritis to two groups AD-203 twice daily or Mucosta^Ⓡ thrice daily for 2 weeks. The intention-to-treat (ITT) analysis included 454 patients (AD-203, n=229; Mucosta^Ⓡ, n=225), and the per-protocol (PP) analysis included 439 patients (AD-203, n=224; Mucosta^Ⓡ, n=215). The posttreatment assessments included the primary (erosion improvement rate) and secondary endpoints (erosion and edema cure rates; improvement rates of redness, hemorrhage, and gastrointestinal symptoms). Drug-related adverse events were evaluated.

Results

According to the ITT analysis, the erosion improvement rates (posttreatment) in AD-203-treated and Mucosta^Ⓡ-treated patients were 39.7% and 43.8%, respectively. According to the PP analysis, the erosion improvement rates (posttreatment) in AD-203-treated and Mucosta^Ⓡ-treated patients were 39.3% and 43.7%, respectively. The one-sided 97.5% lower limit for the improvement rate difference between the study groups was −4.01% (95% confidence interval [CI], –13.09% to 5.06%) in the ITT analysis and −4.44% (95% CI, –13.65% to 4.78%) in the PP analysis. The groups did not significantly differ in the secondary endpoints in either analysis. Twenty-four AD-203-treated and 20 Mucosta^Ⓡ-treated patients reported adverse events but no serious adverse drug reactions; both groups presented similar adverse event rates.

Conclusions

The new formulation of rebamipide 150 mg (AD-203) twice daily was not inferior to rebamipide 100 mg (Mucosta^Ⓡ) thrice daily. Both formulations showed a similar efficacy in treating erosive gastritis.

What is the better surgical treatment option for recurrent common bile duct stones?

Purpose

Repeating endoscopic retrograde cholangiopancreatography (ERCP) in patients with recurrent common bile duct (CBD) stones is problematic in many ways. Choledochoduodenostomy (CDS) and choledochojejunostomy (CJS) are 2 surgical treatment options for recurrent CBD stones, and each has different advantages and disadvantages. The aim of this study was to compare the 2 surgical options in terms of the recurrence rate of CBD stones after surgical treatment.

Methods

This retrospective multicenter study included all patients who underwent surgical treatment due to recurrent CBD stones that were not effectively controlled by medical treatment and repeated ERCP between January 2006 and March 2015. We collected data from chart reviews and medical records. A recurrent CBD stone was defined as a stone found 6 months after the complete removal of a CBD stone by ERCP. Patients who underwent surgery for other reasons were excluded.

Results

A total of 27 patients were enrolled in this study. Six patients underwent CDS, and 21 patients underwent CJS for the rescue treatment of recurrent CBD stones. The median follow-up duration was 290 (180–1,975) days in the CDS group and 1,474 (180–6,560) days in the CJS group (P = 0.065). The postoperative complications were similar and tolerable in both groups (intestinal obstruction; 2 of 27, 7.4%; 1 in each group). CBD stones recurred in 4 patients after CDS (4 of 6, 66.7%), and 3 patients after CJS (3 of 21, 14.3%) (P = 0.010).

Conclusion

CJS may be a better surgical option than CDS for preventing further stone recurrence in patients with recurrent CBD stones.

Recent advances in the diagnosis and management of chronic pancreatitis

Chronic pancreatitis is a chronic condition characterized by pancreatic inflammation that causes fibrosis and the destruction of exocrine and endocrine tissues. Chronic pancreatitis is a progressive disease, and no physiological treatment is available to reverse its course. However, with advances in medical technology, the existing diagnostic and treatment methods for chronic pancreatitis are evolving. Managing patients with chronic pancreatitis is challenging and necessitates a multidisciplinary approach. In this review, we discuss the recent advances in the diagnosis and management of chronic pancreatitis and introduce future alternative modalities.

Robotic transduodenal ampullectomy: A novel minimally invasive approach for ampullary neoplasms

BACKGROUND

The adoption of minimally invasive surgery for transduodenal ampullectomy has been slow because of special characteristics and complexity of this procedure.

METHODS

Six patients underwent robotic transduodenal ampullectomy. We employed novel methods to facilitate exposure of the ampulla.

RESULTS

All patients completed robotic transduodenal ampullectomy, but one patient was immediately converted to robotic pancreaticoduodenectomy because of presence of invasive carcinoma on frozen biopsy. The final pathologic report revealed high-grade dysplasia in four patients, low-grade dyplasia in one, and T2N0 in one patient who converted to pancreaticoduodenectomy. There was no immediate postoperative complication or mortality. One patient was readmitted after 3 months because of stricture of the bile duct outlet. There was no recurrence over a median follow-up period of 20 months.

CONCLUSION

An appropriate combination of patient positioning and retraction method helps the robot surgical system to provide competent performance for sophisticated and precise manipulation of ampullary lesions.

Changes in bursal B cells in chicken during embryonic development and early life after hatching

The bursa of Fabricius, the primary lymphoid organ for B cell development found only in birds, offers novel approaches to study B cell differentiation at various developmental stages. Here, we explored the changes and mechanism involved in the developmental stages of bursal B cells. The bursal B cells rapidly increased in the late embryonic stage and around hatching, which coincided with changes in specific cell surface markers. Moreover, the cells in the bursa were divided by size into small (low forward- and side-scatter) or large (high forward- and side-scatter) via flow cytometry. It is intriguing that the proportion of small and large B cells was reversed during this period. Because little is known about this phenomenon, we hypothesized that size-based B cell population could be used as an indicator to distinguish their status and stage during B cell development in chicken. The results demonstrated that large B cells are actively proliferating cells than small B cells. Additionally, large B cells showed higher mRNA expression of both proliferation- and differentiation-associated genes compared to small B cells. Taken together, these data show that large bursal B cells are the main source of proliferation and differentiation during B cell development in chickens.

Evaluation of valve function in antireflux biliary metal stents

Background

To overcome duodenobiliary reflux induced by biliary stents, antireflux valve (ARV) biliary stents have been developed and showed improvement in stent patency. However, negative study results have also been reported because stent patency may be decreased by the malfunction of ARV itself. Given such mixed results, the true efficacy of ARV remains unknown and the mechanism of its dysfunction needs to be clearly elucidated. The aim of this study was to investigate the exact mechanism of ARV dysfunction using in vitro phantom models.

Methods

Two experimental models were designed to evaluate two important environmental factors suspected to cause ARV malfunction, i.e. bile flow and pH. Three types of ARV metal stents from different companies were used for the experiments: a funnel type ARV, a windsock type ARV, and a wine glass-shaped ARV. Ten stents of each type were tested (five stents in the bile flow phantom model, and another five stents in the duodenal pH environmental model). To determine ARV malfunction, ARV-induced flow resistance was measured using a custom-made testing device. All stents from the two models were removed every 2 weeks for 12 weeks after stent insertion and were evaluated on morphological and functional changes of the ARV.

Results

Only ARV of wine glass-shaped ARV was morphologically changed due to silicone bond detachment in the bile flow model. All types of ARV were morphologically changed in the pH model. The morphological changes of ARV influenced the flow resistance. The antegrade pressure gradients were increased over time in the pH model (p < 0.05).

Conclusions

Morphological change of the ARVs may induce dysfunction of ARV metal stents, which is mainly due to duodenal pH environment. In the future, development of new ARV that is not affected by duodenal environmental factors can be expected to improve stent patency.

Electronic supplementary material

The online version of this article (10.1186/s12876-018-0878-8) contains supplementary material, which is available to authorized users.

H9N2-specific IgG and CD4+CD25+ T cells in broilers fed a diet supplemented with organic acids

Organic acids have long been known for their beneficial effects on growth performance in domestic animals. However, their impact on immune responses against viral antigens in chickens is unclear. The present study aimed to investigate immunological parameters in broilers immunized with a H9N2 vaccine and/or fed a diet containing organic acids (citric, formic, and lactic acids). We allotted 1-day-old broilers into 4 groups: control (C), fed a diet supplemented with organic acids (O), administered a H9N2 vaccine (V), and fed a diet supplemented with organic acids and administered a H9N2 vaccine (OV). Blood and spleen samples were taken at 2, 7 and 14 d post vaccination (DPV). At 14 DPV, total and H9N2-specific IgG levels were significantly lower in the OV group than in the V group. However, it was intriguing to observe that at 2 DPV, the percentage of CD4+CD25+ T cells was significantly higher in the OV group than in the other groups, indicating the potential induction of regulatory T cells by organic acids. In contrast, at 2 DPV, the percentage of CD4+CD28+ T cells were significantly lower in the OV group than in the other groups, suggesting that CD28 molecules are down-regulated by the treatment. The expression of CD28 on CD4+ T cells, up-regulated by the stimulation with phorbol 12-myristate 13-acetate (PMA) and ionomycin (Iono), was inhibited upon organic acid treatment in OV group. In addition, the proliferation of lymphocytes, stimulated with formalin-inactivated H9N2, was significantly higher in the V group than in the OV group. Alpha 1-acid glycoprotein (AGP) production was significantly lower in the OV group than in the V group, suggesting that the organic acids inhibited the inflammation caused by the vaccination. Overall, induction of regulatory CD4+CD25+ T cells, coinciding with the decrease of H9N2-specific antibodies, was observed in broilers fed organic acids.

Transcription Factor KLF10 Constrains IL-17-Committed Vγ4+ γδ T Cells

γδ T cells, known to be an important source of innate IL-17 in mice, provide critical contributions to host immune responses. Development and function of γδ T cells are directed by networks of diverse transcription factors (TFs). Here, we examine the role of the zinc finger TFs, Kruppel-like factor 10 (KLF10), in the regulation of IL-17-committed CD27^- γδ T (γδ^27--17) cells. We found selective augmentation of Vγ4⁺ γδ^27- cells with higher IL-17 production in KLF10-deficient mice. Surprisingly, KLF10-deficient CD127^hi Vγ4⁺ γδ^27--17 cells expressed higher levels of CD5 than their wild-type counterparts, with hyper-responsiveness to cytokine, but not T-cell receptor, stimuli. Thymic maturation of Vγ4⁺ γδ^27- cells was enhanced in newborn mice deficient in KLF10. Finally, a mixed bone marrow chimera study indicates that intrinsic KLF10 signaling is requisite to limit Vγ4⁺ γδ^27--17 cells. Collectively, these findings demonstrate that KLF10 regulates thymic development of Vγ4⁺ γδ^27- cells and their peripheral homeostasis at steady state.

Experimental study on the friction effect of plastic stents for biliary stone fragmentation (with video)

BACKGROUND AND AIM

In patients with irretrievable or intractable bile duct stone, temporary insertion of a plastic stent (PS) followed by further endoscopic retrograde cholangiopancreatography (ERCP) or surgery has been recommended as a 'bridge' therapy. However, the exact mechanism of stone fragmentation has not been discovered. The aim of the present study was to evaluate whether PS shape can facilitate stone fragmentation.

METHODS

Using a new in vitro bile flow phantom model, we compared the friction effect among three different PS groups (straight PS group, double pigtail-shaped PS group, and screw-shaped PS group) and a control group. Each group had 10 silicon tube blocks that separately contained one stone and two PS. The control group had 10 blocks each with only a stone and no PS. We carried out analysis of the friction effect by stone weight and volume changes among the groups, excluding fragmented stones.

RESULTS

After 8 weeks, complete fragmentation was noted in one out of 34 cholesterol stones (2.9%) and in four out of six pigmented stones (66.7%). Fragmentation tended to be more prominent in the screw-shaped PS group than in the straight PS group, double pigtail-shaped group, and control group (volume change: -11.33%, 7.94%, 4.43%, and 2.05%, respectively, P = 0.1390; weight change: -9.30%, 0.71%, -0.10%, and -1.23%, respectively, P = 0.3553).

CONCLUSION

Stone fragmentation may be induced by PS friction effect. Also, screw-shaped plastic stents may improve friction effect. These results may help guide future PS development and clinical decisions.

Synthetic 8-hydroxydeoxyguanosine inhibited metastasis of pancreatic cancer through concerted inhibitions of ERM and Rho-GTPase

8-hydroxydeoxyguanosine (8-OHdG) is generated consequent to oxidative stress, but its paradoxical anti-oxidative, anti-inflammatory, and anti-mutagenic effects via Rho-GTPase inhibition were noted in various models of inflammation and cancer. Metastasis occurs through cell detachment, epithelial-mesenchymal transition (EMT), and cell migration; during these processes, changes in cell morphology are initiated through Rho-GTPase-dependent actin cytoskeleton polymerization. In this study, we explored the anti-metastatic mechanisms of 8-OHdG in Panc-1 pancreatic cancer cells. 8-OHdG inhibits cell migration by inactivating ERM and Rho-GTPase proteins, and inhibiting focal adhesion kinase (FAK) and matrix metalloproteinases (MMPs). At 15min, 8-OHdG significantly inactivated ERM (p < 0.05) and led to a significant retardation of wound healing; siERM and H1152 (ROCK inhibitor) had similar effects (p < 0.05). However, FAK inhibitor 14, DPI (NOX inhibitor), and NAC (antioxidant) significantly delayed wound healing without inhibiting ERM or CD44 (p < 0.05). In the experiments on cell migration, siERM, siCD44, DPI, and 8-OHdG significantly inhibited MMPs. 8-OHdG significantly decreased DCF-DA activation in Panc-1 pancreatic cancer cells and down-regulated NOXs (nox-1, nox-2, and nox-3). Finally, all of these anti-migration actions of 8-OHdG resulted in significant inhibition of EMT, as evidenced by the up-regulation of ZO-1 and claudin-1 and down-regulation of vimentin. We found significant inhibition of lung metastasis of Panc-1 cells by 8-OHdG. In conclusion, exogenous 8-OHdG had potent anti-metastasis effects mediated by either ERM or Rho GTPase inhibition in metastasis-prone pancreatic cancer cells.

Bile Flow Phantom Model and Animal Bile Duct Dilation Model for Evaluating Biliary Plastic Stents with Advanced Hydrophilic Coating

Background/Aims

The efforts to improve biliary plastic stents (PSs) for decreasing biofilm formation and overcome short patency time have been continued. The aim of this study is to evaluate the effect of advanced hydrophilic coating for patency and biodurability of PS.

Methods

Using an in vitro bile flow phantom model, we compared patency between prototype PS with hydrophilic coating (PS+HC) and prototype PS without hydrophilic coating (PS−HC). We performed an analysis of the degree of luminal narrowing by microscopic examination. Using an in vivo swine bile duct dilation model made by endoscopic papillary closure and stent insertion, we evaluated biodurability of hydrophilic coating.

Results

In the phantom model, PS+HC showed less biofilm formation and luminal narrowing than PS−HC at 8 weeks (p<0.05). A total of 31 stents were inserted into the dilated bile duct of seven swine models, and 24 stents were successfully retrieved 8 weeks later. There was no statistical difference of stent patency between the polyethylene PS+HC and the polyurethane PS+HC. The biodurability of hydrophilic coating was sustained up to 8 weeks, when assessing the coating layer by scanning electron microscopy examination.

Conclusions

Advanced hydrophilic coating technology may extend the patency of PS compared to uncoated PS.

Emerging Targets to Relieve Fat Stress-Induced Liver Diseases: UDCA, Tocotrienol, ω-3 PUFAs, and IgY Targeted NPC1L1 Cholesterol Transporter

Fat stress-induced liver disease is a hepatic manifestation of metabolic syndrome initiated by excess fat accumulation and encompasses a wide spectrum of diseases from non-alcoholic fatty liver disease to nonalcoholic steatohepatitis, a precursor lesion progressing to more aggressive liver cirrhosis and hepatocellular carcinoma. Although the incidence of these fat stress-induced liver diseases is rapidly increasing worldwide in parallel with the growing epidemics of obesity and metabolic diseases, its exact pathogenesis is not well defined. Although obesity, sedentary life-style, altered dietary pattern, insulin resistance, altered intestinal barrier function, inflammatory cytokines, and oxidative stress have been acknowledged as contributing factors because of the indefinite pathogenesis of metabolic diseases, the only reliable treatment is lifestyle intervention composed of restrictive diet and exercise. Additionally, some existing medications such as pioglitazone and antioxidants such as vitamin E were reported to be effective; in this review, several novel agents especifically targeting nonalcoholic fatty liver disease pathogenesis under clinical trial will be introduced. These include an NPC1L1 blocker (ezetimibe), which significantly improved histological and symptomatic scores associated with steatohepatitis and fibrosis; clofibrate, phentoxyfylline, ursodeoxycholic acid, and tocopherol, all of which are prescribed to relieve fat stress; and additional IgY targeted NPC1L1, tocotrienol, ursodeoxycholic acid, and ω-3 polyunsaturated fatty acids, which are actively under investigation to confirm the safety of long-term use.

Hominin interbreeding and the evolution of human variation

Mitochondrial Eve confirms the “out of Africa” theory, but the evidence also supports interbreeding between Homo sapiens and other hominins: Neanderthals, Denisovans, and Homo heidelbergensis. This article explains how interbreeding between early H. sapiens and archaic hominins occurred. The availability of edible insects in East Asia aided the spread of the unaggressive, highly cooperative Neanderthals, who interbred with H. sapiens in Asia, resulting in a higher admixture of Neanderthal DNA in East Asian populations. Geographical variation in degree of interbreeding between H. sapiens and Neanderthals likely contributed to neurological and behavioral differences in modern humans. Similarly, people with Denisovan genetic admixture were better able to dwell in mountainous regions, allowing their genetic legacy to cross the Himalayas and persist in Southeast Asian and Oceanian H. sapiens. In the Sub-Saharan region, unaffected by Denisovan or Neanderthal interbreeding, H. sapiens interbred with H. heidelbergensis, because high humidity militated against fire-making and allowed the survival of these non-fire-making hominins.

Mutagenicity and Immune Toxicity of Emulsion-type Sausage Cured with Plasma-treated Water

Cold plasma has been developed to reduce microbial contamination and to improve safety of food and medical products. In addition, the technology can be used in the manufacture of sausages without addition of nitrite. To be applied in food industry commercially, the new technology should be safe and efficient. However, toxicological test of plasma-treated food is limited. Therefore, the purpose of this study was to determine the mutagenicity and immune toxicity of the meat products cured with plasma-treated water (PTW) as a nitrite source. Emulsion sausages were prepared with no nitrite (control), sodium nitrite (SCS), and PTW (SCP). For a mutagenicity test, the Ames test was performed with the sausage samples. For immune toxicity test, 8-wk-old female Balb/c mice were given free access to the sausages in order to evaluate the tumor necrosis factor (TNF)-α level. As a result, no mutagenicity was detected in the sausages by the Ames test. The serum TNF-α values were less than 10 pg/mL in mice after feeding control and treated samples for 32 d, indicating that no inflammatory response was occurred by feeding the sausages made by PTW. Therefore, the present study opens the possibility of using plasma-treated water as a nitrite source without any toxicity.

Common Bile Duct Obstruction Due to a Large Stone at the Duodenal Stump

Enterolith is a rare complication of Billroth II gastrectomy. Most enterolith cases have been reported in association with diverticula, tuberculosis, and Crohn's disease. We report the case of a huge enterolith that developed in the duodenal stump following common bile duct obstruction and cholangitis, necessitating surgery. The enterolith was clearly visible on the abdominal computed tomography. It was removed through a duodenotomy. The surgery was successful without any significant complications.

Optimal Methods for the Management of Iatrogenic Colonoscopic Perforation

Background/Aims:

Colonoscopic perforations have been managed with exploratory laparotomy, and have resulted in some morbidity and mortality. Recently, laparoscopic surgery is commonly performed for this purpose. The aim of this study was to compare the outcomes of several management strategies for iatrogenic colonoscopic perforations.

Methods:

We retrospectively reviewed the medical records of patients who had been treated for colonoscopic perforation between January 2004 and April 2013 at CHA Bundang Medical Center in Korea.

Results:

A total of 41 patients with colonoscopic perforation were enrolled. Twenty patients underwent conservative management with a success rate of 90%. Surgical management was performed in 23 patients including two patients who were converted to surgical management after the failure of the initial conservative management. Among 14 patients who underwent surgery at 8 hours after the perforation, there was no considerable difference in adverse outcomes between the laparotomy group and the laparoscopic surgery group. The medical costs and claim rate were 1.45 and 1.87 times greater in the exploratory laparotomy group, respectively.

Conclusions:

Conservative management of colonoscopic perforation could be an option for patients without overt symptoms of peritonitis or with a small defect size. If surgical management is required, laparoscopic surgery may be considered as the initial procedure even with a delayed diagnosis.

Image Quality Analysis of Various Gastrointestinal Endoscopes: Why Image Quality Is a Prerequisite for Proper Diagnostic and Therapeutic Endoscopy

Arising from human curiosity in terms of the desire to look within the human body, endoscopy has undergone significant advances in modern medicine. Direct visualization of the gastrointestinal (GI) tract by traditional endoscopy was first introduced over 50 years ago, after which fairly rapid advancement from rigid esophagogastric scopes to flexible scopes and high definition videoscopes has occurred. In an effort towards early detection of precancerous lesions in the GI tract, several high-technology imaging scopes have been developed, including narrow band imaging, autofocus imaging, magnified endoscopy, and confocal microendoscopy. However, these modern developments have resulted in fundamental imaging technology being skewed towards red-green-blue and this technology has obscured the advantages of other endoscope techniques. In this review article, we have described the importance of image quality analysis using a survey to consider the diversity of endoscope system selection in order to better achieve diagnostic and therapeutic goals. The ultimate aims can be achieved through the adoption of modern endoscopy systems that obtain high image quality.

Extragastroesophageal Malignancy-Associated Secondary Achalasia: A Rare Association of Pancreatic Cancer Rendering Alarm Manifestation

Secondary achalasia or pseudoachalasia is a rare esophageal motor abnormality, which mimics primary achalasia; it is not easily distinguishable from idiopathic achalasia by manometry, radiological examination, or endoscopy. Although the majority of reported pseudoachalasia cases are associated with neoplasms at or near the esophagogastric (EG) junction, other neoplastic processes or even chronic illnesses such as rheumatoid arthritis can lead to the development of pseudoachalasia, for example, mediastinal masses, gastrointestinal (GI) tumors of the liver and biliary tract, and non-GI malignancies. Therefore, even if a patient presents with the typical findings of achalasia, we should be alert to the possibility of other GI malignancies besides EG tumors. For instance, pancreatic cancer was found in the case reported here; only four such cases have been reported in the literature. A 47-year-old man was admitted to our center with a 3-month history of dysphagia. His endoscopic and esophageal manometric findings were compatible with primary achalasia. However, unresponsiveness to diverse conventional achalasia treatments led us to suspect secondary achalasia. An active search led to a diagnosis of pancreatic mucinous cystadenocarcinoma invading the gastric fundus and EG junction. This rare case of pseudoachalasia caused by pancreatic carcinoma emphasizes the need for suspecting GI malignancies other than EG tumors in patients refractory to conventional achalasia treatment.

Bio-sheet graft therapy for artificial gastric ulcer after endoscopic submucosal dissection: an animal feasibility study

BACKGROUND

Various bio-sheet grafts have been attempted either to accelerate healing of artificial ulcers or to prevent adverse events after endoscopic submucosal dissection (ESD), but neither prospective nor mechanistic studies were available.

OBJECTIVE

To evaluate the substantial effect of a bio-sheet graft on artificial ulcer healing and its feasibility as an endoscopic treatment modality.

DESIGN

Preclinical, in vivo animal experiment and proof-of-concept study.

SETTING

Animal laboratory.

SUBJECTS

Three mini-pigs, Sus scrofa, mean age 14 months.

INTERVENTION

Multiple ulcers sized 2.5 cm in diameter were generated by ESD in 3 mini-pigs and were assigned randomly into the following 3 groups; control group, bio-sheet group, or combination (bio-sheet plus drug) group. Bio-sheet grafts or bio-sheet plus drug combinations were applied on the artificial ulcers immediately after the ESD.

MAIN OUTCOME MEASUREMENTS

Feasibility and efficacy of endoscopic bio-sheet graft therapy for the management of artificial ulcers and the evaluation of healing conditions based on histology changes in the remaining gastric bed tissues harvested from the stomachs.

RESULTS

Thirty-three ESD specimens were obtained. On an image analysis of the ratio of healed area in the remaining gastric bed tissue compared with the matched dissected gastric mucosa, the control group showed the most significant improvement in healing activity among the 3 groups (P < .05), whereas the severity of inflammation in the remaining ulcer tissue was significantly attenuated in bio-sheet and combination groups (P < .05).

LIMITATIONS

Animal model.

CONCLUSION

Although the bio-sheet grafts provided physical protection from gastric acid attack as reflected in the attenuated inflammation on the ulcer beds, unexpected delayed ulcer healing was noted in the bio-sheet graft group because of its physical hindrance of the healing process.

Association between folate metabolism-related polymorphisms and colorectal cancer risk

Folate has essential roles in DNA synthesis, repair and methylation. Folate metabolism-related gene variants may modulate the levels of this vitamin and affect the cancer risk. Thus, whether these polymorphisms play an important role in carcinogenesis, particularly colorectal cancer (CRC) development, has been a subject interest. The present study investigated the association between polymorphisms in the methylenetetrahydrofolate reductase (MTHFR), thymidylate synthase (TS) and the reduced folate carrier 1 (RFC1) genes and CRC risk. Polymorphisms in MTHFR (677C>T and 1298A>C), TS [1494del6 and the TS enhancer region (TSER)] and RFC1 (-43T>C, 80G>A and 696C>T) were characterized using polymerase chain reaction-restriction fragment length polymorphism in 477 CRC cases and 514 controls. Although no polymorphisms were significantly associated with the CRC risk in the overall sample, significant associations between folate metabolism-related polymorphisms and CRC risk were identified in the stratified analyses. The MTHFR 677CT/1298AC and MTHFR 1298AC+CC/TSER 2R3R genotypes in the presence of plasma folate levels ≤4.12 ng/ml were associated with significantly increased CRC risk. In addition, individuals with the MTHFR 677TT/TSER 3R3R or MTHFR 677/TSER 3R3R/TS 1494 0bp6bp+6bp6bp genotypes and diabetes mellitus (DM) were at an increased risk for CRC. Therefore, the data suggest that i) MTHFR polymorphisms combined with low plasma folate levels and ii) polymorphisms in folate metabolism-related genes combined with metabolic syndrome risk factors (hypertension and DM) increase the odds of developing CRC.

Endoscopic Submucosal Dissection Using a Novel Versatile Knife: An Animal Feasibility Study (with Video)

Background/Aims

In order to reduce the procedure time and the number of accessory changes during endoscopic submucosal dissection (ESD), we developed a novel versatile knife, which has the combined advantages of several conventional knives. The aim of this study was to compare the efficacy, safety, and histological quality of ESD performed using this novel versatile knife and a combination of several conventional knives.

Methods

This was an in vivo animal study comparing two different modalities of ESD in mini-pigs. Completion time of each resection was documented, and the resected specimens were retrieved and evaluated for completeness. To assess the quality control of the procedures and adverse events, detailed histopathological examinations were performed.

Results

A total of 18 specimens were dissected by ESD safely and easily (nine specimens using the new versatile knife; nine specimens by mixing conventional knives). All resections were completed as en bloc resections. There was no significant difference in procedure time between the 2 modalities (456 seconds vs. 355 seconds, p=0.258) and cutting speed (1.983 mm²/sec vs. 1.57 mm²/sec, p=1.000). The rate of adverse events and histological quality did not statistically differ between the modalities.

Conclusions

ESD with a versatile knife appeared to be an easy, safe, and technically efficient method.

Antioxidative phytoceuticals to ameliorate pancreatitis in animal models: An answer from nature

Despite enthusiastic efforts directed at elucidating critical underlying mechanisms towards the identification of novel therapeutic targets for severe acute pancreatitis (SAP), the disease remains without a specific therapy to be executed within the first hours to days after onset of symptoms. Although earlier management for SAP should aim to either treat organ failure or reduce infectious complications, the current standard of care for the general management of AP in the first hours to days after onset of symptoms include intravenous fluid replacement, nutritional changes, and the use of analgesics with a close monitoring of vital signs. Furthermore, repeated evaluation of severity is very important, as the condition is particularly unstable in the early stages. In cases where biliary pancreatitis is accompanied by acute cholangitis or in cases where biliary stasis is suspected, an early endoscopic retrograde cholangiopancreatography is recommended. However, practice guidelines regarding the treatment of pancreatitis are suboptimal. In chronic pancreatitis, conservative management strategies include lifestyle modifications and dietary changes followed by analgesics and pancreatic enzyme supplementation. Recently, attention has been focused on phytoceuticals or antioxidants as agents that could surpass the limitations associated with currently available therapies. Because oxidative stress has been shown to play an important role in the pathogenesis of pancreatitis, antioxidants alone or combined with conventional therapy may improve oxidative-stress-induced organ damage. Interest in phytoceuticals stems from their potential use as simple, accurate tools for pancreatitis prognostication that could replace older and more tedious methods. Therefore, the use of antioxidative nutrition or phytoceuticals may represent a new direction for clinical research in pancreatitis. In this review article, recent advances in the understanding of the pathogenesis of pancreatitis are discussed and the paradigm shift underway to develop phytoceuticals and antioxidants to treat it is introduced. Despite the promise of studies evaluating the effects of antioxidants/phytoceuticals in pancreatitis, translation to the clinic has thus far been disappointing. However, it is expected that continued research will provide solid evidence to justify the use of antioxidative phytoceuticals in the treatment of pancreatitis.

Nrf2-mediated mucoprotective and anti-inflammatory actions of Artemisia extracts led to attenuate stress related mucosal damages

The aim of this study was to compare biological actions between isopropanol and ethanol extracts of Artemisia including antioxidant, anti-inflammatory, and cytoprotective actions. Antioxidant activities were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) method and confocal microscopy on lipopolysaccharide-induced RGM1 cells, cytoprotection effects evaluated by detecting heme oxygenase-1 (HO-1), Nf-E2 related factor2 (Nrf2) and heat shock protein 70 (HSP70), and anti-inflammatory effects investigated by measuring inflammatory mediators. Water immersion restraint stress was imposed to provoke stress related mucosal damages (SRMD) in rats. Isopropanol extracts of Artemisia showed the higher DPPH radical scavenging activity and lesser LPS-induced reactive oxygen species productions and increased HO-1 expression through increased nuclear translocation of Nrf2 transcription factor compared to ethanol extracts. The increased expression of HSP70 and decreased expression of endothelin-1 were only increased with isopropanol extracts. A concentration-dependent inhibition of LPS-induced COX-2 and iNOS even at a rather lower concentration than ethanol extract was achieved with isopropanol extracts. Cytokine protein array revealed Artemisia extracts significantly attenuated the levels of CXCL-1, CXCL-16, and MCP-1. These orchestrated actions led to significant rescue from SRMD. Conclusively, Artemisia extracts imposed significant antioxidant and anti-inflammatory activity against SRMD and isopropanol extracts were superior to ethanol extracts in these beneficiary actions of Artemisia.

Predictive proteomic biomarkers for inflammatory bowel disease-associated cancer: Where are we now in the era of the next generation proteomics?

Recent advances in genomic medicine have opened up the possibility of tailored medicine that may eventually replace traditional “one-size-fits all” approaches to the treatment of inflammatory bowel disease (IBD). In addition to exploring the interactions between hosts and microbes, referred to as the microbiome, a variety of strategies that can be tailored to an individual in the coming era of personalized medicine in the treatment of IBD are being investigated. These include prompt genomic screening of patients at risk of developing IBD, the utility of molecular discrimination of IBD subtypes among patients diagnosed with IBD, and the discovery of proteome biomarkers to diagnose or predict cancer risks. Host genetic factors influence the etiology of IBD, as do microbial ecosystems in the human bowel, which are not uniform, but instead represent many different microhabitats that can be influenced by diet and might affect processes essential to bowel metabolism. Further advances in basic research regarding intestinal inflammation may reveal new insights into the role of inflammatory mediators, referred to as the inflammasome, and the macromolecular complex of metabolites formed by intestinal bacteria. Collectively, knowledge of the inflammasome and metagenomics will lead to the development of biomarkers for IBD that target specific pathogenic mechanisms involved in the spontaneous progress of IBD. In this review article, our recent results regarding the discovery of potential proteomic biomarkers using a label-free quantification technique are introduced and on-going projects contributing to either the discrimination of IBD subtypes or to the prediction of cancer risks are accompanied by updated information from IBD biomarker research.

Molecular imaging for theranostics in gastroenterology: one stone to kill two birds

Molecular imaging in gastroenterology has become more feasible with recent advances in imaging technology, molecular genetics, and next-generation biochemistry, in addition to advances in endoscopic imaging techniques including magnified high-resolution endoscopy, narrow band imaging or autofluorescence imaging, flexible spectral imaging color enhancement, and confocal laser endomicroscopy. These developments have the potential to serve as "red flag" techniques enabling the earlier and accurate detection of mucosal abnormalities (such as precancerous lesions) beyond biomarkers, virtual histology of detected lesions, and molecular targeted therapy-the strategy of "one stone to kill two or three birds"; however, more effort should be done to be "blue ocean" benefit. This review deals with the introduction of Raman spectroscopy endoscopy, imaging mass spectroscopy, and nanomolecule development for theranostics. Imaging of molecular pathological changes in cells/tissues/organs might open the "royal road" to either convincing diagnosis of diseases that otherwise would only be detected in the advanced stages or novel therapeutic methods targeted to personalized medicine.

Recent advances in molecular imaging of premalignant gastrointestinal lesions and future application for early detection of barrett esophagus

Recent advances in optical molecular imaging allow identification of morphologic and biochemical changes in tissues associated with gastrointestinal (GI) premalignant lesions earlier and in real-time. This focused review series introduces high-resolution imaging modalities that are being evaluated preclinically and clinically for the detection of early GI cancers, especially Barrett esophagus and esophageal adenocarcinoma. Although narrow band imaging, autofluorescence imaging, and chromoendoscopy are currently applied for this purpose in the clinic, further adoptions of probe-based confocal laser endomicroscopy, high-resolution microendoscopy, optical coherence tomography, and metabolomic imaging, as well as imaging mass spectrometry, will lead to detection at the earliest and will guide predictions of the clinical course in the near future in a manner that is beyond current advancements in optical imaging. In this review article, the readers will be introduced to sufficient information regarding this matter with which to enjoy this new era of high technology and to confront science in the field of molecular medical imaging.

Application of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Imaging Mass Spectrometry (MALDI-TOF IMS) for Premalignant Gastrointestinal Lesions

Imaging mass spectrometry (IMS) is currently receiving large attention from the mass spectrometric community, although its use is not yet well known in the clinic. As matrix-assisted laser desorption/ionization time-of-flight (MALDI)-IMS can show the biomolecular changes in cells as well as tissues, it can be an ideal tool for biomedical diagnostics as well as the molecular diagnosis of clinical specimens, especially aimed at the prompt detection of premalignant lesions much earlier before overt mass formation, or for obtaining histologic clues from endoscopic biopsy. Besides its use for pathologic diagnosis, MALDI-IMS is also a powerful tool for the detection and localization of drugs, proteins, and lipids in tissue. Measurement of parameters that define and control the implications, challenges, and opportunities associated with the application of IMS to biomedical tissue studies might be feasible through a deep understanding of mass spectrometry. In this focused review series, new insights into the molecular processes relevant to IMS as well as other field applications are introduced.

Prevalence of occult hepatitis B virus infection in hemodialysis patients

BACKGROUND/AIMS

The prevalence of occult HBV infection depends on the prevalence of HBV infection in the general population. Hemodialysis patients are at increased risk for HBV infection. The aim of this study was to determine the prevalence of occult HBV infection in hemodialysis patients.

METHODS

Total of 98 patients undergoing hemodialysis in CHA Bundang Medical Center (Seongnam, Korea) were included. Liver function tests and analysis of HBsAg, anti-HBs, anti-HBc and anti-HCV were performed. HBV DNA testing was conducted by using two specific quantitative methods.

RESULTS

HBsAg was detected in 4 of 98 patients (4.1%), and they were excluded. Among 94 patients with HBsAg negative and anti-HCV negative, one (1.1%) patient with the TaqMan PCR test and 3 (3.2%) patients with the COBAS Amplicor HBV test were positive for HBV DNA. One patient was positive in both methods. Two patients were positive for both anti-HBs and anti-HBc and one patient was negative for both anti-HBs and anti-HBc.

CONCLUSIONS

The present study showed the prevalence of occult HBV infection in HBsAg negative and anti-HCV negative patients on hemodialysis at our center was 3.2%. Because there is possibility of HBV transmission in HBsAg negative patients on hemodialysis, more attention should be given to prevent HBV transmission.

Functional self-expandable metal stents in biliary obstruction

Biliary stents are widely used not only for palliative treatment of malignant biliary obstruction but also for benign biliary diseases. Each plastic stent or self-expandable metal stent (SEMS) has its own advantages, and a proper stent should be selected carefully for individual condition. To compensate and overcome several drawbacks of SEMS, functional self-expandable metal stent (FSEMS) has been developed with much progress so far. This article looks into the outcomes and defects of each stent type for benign biliary stricture and describes newly introduced FSEMSs according to their functional categories.

Gastrointestinal cancers in a peutz-jeghers syndrome family: a case report

A 17-year-old man was diagnosed as Peutz-Jeghers syndrome (PJS) because of pigmented lip and multiple gastrointestinal polyps. He had anemia and underwent polypectomy on the duodenum and colon. His maternal family members were patients with PJS. His mother used to be screened with endoscopy to remove large polyps. One and half years later, he underwent jejunal segmental resection due to intussusceptions. He underwent endoscopic polypectomy every 2 to 3 years. When he was 23 years old, high-grade dysplasia was found in colonic polyp and his mother underwent partial pancreatectomy due to intraductal papillary mucinous carcinoma. When he was 27 years old, diffuse gastric polyps on the greater curvature of corpus expanded and grew. Therefore, wide endoscopic polypectomy was done. Histological examination revealed focal intramucosal carcinoma and low-grade dysplasia in hamartomatous polyps. We report cases of cancers occurred in first-degree relatives with PJS.

Angular positioning of stent increases bowel perforation after self-expandable metal stent placement for malignant colorectal obstruction

Background/Aims

Some factors like stent wires, balloon dilatation and use of guide wires seems to increase perforation after self-expandable metal stent (SEMS) placement, but few studies mentioned about the relationship between angulation of malignant stricture and perforation. The present study aimed to confirm that more angular positioning of stents increases perforation.

Methods

This study was conducted with retrospectively evaluation at Digestive Disease Center, CHA Bundang Medical Center, CHA University. Between January 2002 and August 2011, SEMS was inserted in 130 patients with malignant colorectal obstruction. We studied the difference in the angle of stenosis between perforation and non-perforation groups using fluorography images.

Results

SEMS insertion was performed in 130 cases of obstruction due to colon cancer. Perforation occurred in eight patients (6.2%) of them. Thirteen cases were excluded from the analysis due to poor fluoroscopic images. Among the eight patients with perforation, the mean stenosis angle was 109.9° compared to 153.1° in the nonperforation group, indicating that the angle was more acute in the perforation group (p=0.016).

Conclusions

This study shows that more angular positioning of stent increases bowel perforation after SEMS placement for malignant colorectal obstruction.

Unusual complications related to endoscopic retrograde cholangiopancreatography and its endoscopic treatment

Endoscopic retrograde cholangiopancreatography (ERCP)-induced complications, once occurred, can lead to significant morbidity. Commonly 5% to 10% of patients experience procedure related complications such as post-ERCP pancreatitis, biliary hemorrhage, and cholangitis, in descending order. However, complications such as perforation, pneumothorax, air embolism, splenic injury, and basket impaction are rare but are associated with high mortality if occurred. Such unexpected unusual complications might extend the length of hospitalization, require urgent surgical intervention, and put the patient in miserable condition leading to permanent disability or mortality. Although these ERCP-induced complications can be minimized by a skilled operator using advanced techniques and devices, the occurrence of unusual complications are hard to expect and induce very difficult management condition. In this review, we will focus on the uncommon complications related to ERCP. This review is also aimed at suggesting optimal endoscopic treatment strategies for several complications based on our institutional experiences.

New antireflux self-expandable metal stent for malignant lower biliary obstruction: in vitro and in vivo preliminary study

AIM

Antireflux plastic biliary stents prevent duodenal biliary reflux and improve the stent patency rate. However, the efficacy of the antireflux valve in a self-expandable metal stent (SEMS) for a malignant biliary obstruction has not been well established. We evaluated the efficacy of a SEMS with an antireflux valve using in vitro flow studies and determined the impact of reducing duodenobiliary reflux on the stent patency rate.

METHODS

In vitro testing was conducted using a bile perfusion system to evaluate the antegrade and retrograde flow resistance, and to determine the ideal shape for the valve. Then, a prospective case series in humans was conducted with an adequately designed SEMS with an antireflux valve.

RESULTS

During the study period, five patients with an unresectable non-hilar malignant biliary obstruction underwent insertion of a SEMS with an antireflux valve. Placement of the SEMS with antireflux valve was successful on the first attempt in all patients, and no procedure-related complications occurred. Follow up was obtained in all cases. Serum bilirubin level did not decrease to the normal range within 1 month in four patients. Stent occlusions occurred in all four patients as a result of valve malfunctions due to sludge impaction or a clog. Therefore, the study was terminated early due to unexpected results.

CONCLUSION

SEMS with an antireflux valve was ineffective in patients with non-hilar malignant biliary obstruction due to limitations on current stent technology.

Rifaximin Plus Levofloxacin-Based Rescue Regimen for the Eradication of Helicobacter pylori

Background/Aims

This study assessed the efficacy of a rifaximin plus levofloxacin-based rescue regimen in patients that had failed both triple and quadruple standard regimens for the eradication of Helicobacter pylori.

Methods

We treated patients for H. pylori between August 2009 and April 2011. The triple regimen consisted of combined treatment with amoxicillin, clarithromycin, and pantoprazole for 1 week. For failed cases, a quadruple regimen of tetracycline, metronidazole, bismuth dicitrate, and lansoprazole for 1 week was administered. The rescue regimen for persistently refractory cases was rifaximin 200 mg t.i.d., levofloxacin 500 mg q.d., and lansoprazole 15 mg b.i.d. for 1 week.

Results

In total, 482 patients were enrolled in this study. The eradication rates associated with the first and second regimens were 58% and 60%, respectively. Forty-seven out of 58 patients who failed with the second-line regimen received rifaximin plus levofloxacin-based third-line therapy. The eradication rate for the third regimen was 65%. The cumulative eradication rates were 58%, 85%, and 96% for each regimen, respectively.

Conclusions

A rifaximin plus levofloxacin-based regimen could be an alternative rescue therapy in patients with resistance to both triple and quadruple regimens for the eradication of H. pylori.