Clinical outcomes of colorectal endoscopic submucosal dissection and risk factors associated with piecemeal resection

BACKGROUND/AIMS

We aimed to investigate the factors associated with piecemeal resection of colorectal neoplasia (CRN), in spite of endoscopic submucosal dissection (ESD).

MATERIALS AND METHODS

We analyzed the retrospective data for colorectal ESD cases from January 2005 to April 2014. We also reviewed the piecemeal endoscopic mucosal resection (EMR) for CRNs ≥20 mm, performed over the same period.

RESULTS

En bloc resection was possible in 648 (85.7%) of 756 lesions in 740 patients. Multivariate analysis showed that hybrid ESD (odds ratio (OR), 29.07; 95% confidence interval (CI), 15.46-54.65; p<0.01) and mild or severe submucosal fibrosis (OR, 3.62; 95% CI, 1.94-6.76; p<0.01) were independently associated with piecemeal ESD. The en bloc ESD group showed higher histologic complete resection rate than the piecemeal ESD group (80.4% vs. 56.5%; p<0.01), and the piecemeal ESD group showed higher recurrence rate than in the en bloc ESD group (5.6% [4/72] vs. 0.7% [3/450]; p<0.01). Overall recurrence rate was 1.3% (7/522).

CONCLUSION

Hybrid ESD and submucosal fibrosis are independently associated with piecemeal ESD. Piecemeal ESD cases recurred more frequently than en bloc ESD cases.

Influence of anti-tumor necrosis factor-alpha therapy to pregnant inflammatory bowel disease women and their children's immunity

Background/Aims

The onset of inflammatory bowel disease (IBD) usually occurs at young age, and therefore, women IBD patients experience pregnancy during their disease progression. Recently, the use of anti-tumor necrosis factor-α (anti-TNF-α) has been rapidly increasing. The aim of this study was to evaluate pregnancy related outcomes in women with IBD who were treated with anti-TNF-α during pregnancy and immunity of their children.

Methods

Korean women with IBD who had been treated with anti-TNF-α during pregnancy had been enrolled. Medical records were reviewed and a survey was performed for each patient. For the patients who agreed on additional examination for their children, children’s growth, medical history and antibody to hepatitis B surface antigen (anti-HBs) titer were checked.

Results

All 18 patients had been diagnosed with Crohn’s disease. There was not any case of preterm delivery, low birth-weight infant, congenital anomaly, nor stillbirth. All 12 children had followed the regular vaccination schedule for hepatitis B and 4 of them showed negative results for anti-HBs. After the 1 booster vaccination, all children demonstrated seroconversion. Regarding live vaccines, 4 children had bacillus Calmette-Guerin and 4 had rotavirus vaccine before 6 months, without any specific side effects.

Conclusions

This was the first study of immunity of the children born from IBD women who had been treated with anti-TNF-α medication during their pregnancy. IBD women had comparable pregnancy outcomes with the general women population, suggesting that the disease activity rather than the administered medication would be more important in healthy pregnancy. Considering the history of vaccination and anti-HBs titers, immunity seems to be intact in the children.

Colonic Pseudo-obstruction With Transition Zone: A Peculiar Eastern Severe Dysmotility

Background/Aims

Previous studies from Korea have described chronic intestinal pseudo-obstruction (CIPO) patients with transition zone (TZ) in the colon. In this study, we evaluated the pathological characteristics and their association with long-term outcomes in Korean colonic pseudo-obstruction (CPO) patients with TZ.

Methods

We enrolled 39 CPO patients who were refractory to medical treatment and underwent colectomy between November 1989 and April 2016 (median age at symptoms onset: 45 [interquartile range, 29–57] years, males 46.2%). The TZ was defined as a colonic segment connecting a proximally dilated and distally non-dilated segment. Detailed pathologic analysis was performed.

Results

Among the 39 patients, 37 (94.9%) presented with TZ and 2 (5.1%) showed no definitive TZ. Median ganglion cell density in the TZ adjusted for the colonic circumference was significantly decreased compared to that in proximal dilated and distal non-dilated segments in TZ (+) patients (9.2 vs 254.3 and 150.5, P < 0.001). Among the TZ (+) patients, 6 showed additional pathologic findings including eosinophilic ganglionitis (n = 2), ulcers with combined cytomegalovirus infection (n = 2), diffuse ischemic changes (n = 1), and heterotropic myenteric plexus (n = 1). During follow-up (median, 61 months), 32 (82.1%) TZ (+) patients recovered without symptom recurrence after surgery. The presence of pathological features other than hypoganglionosis was an independent predictor of symptom recurrence after surgery (P = 0.046).

Conclusions

Hypoganglionosis can be identified in the TZ of most Korean CPO patients. Detection of other pathological features in addition to TZ-associated hypoganglionosis was associated with poor post-operative outcomes.

Development, validation, and application of a novel tool to measure disease-related knowledge in patients with inflammatory bowel disease

BACKGROUND/AIMS

The Crohn's and Colitis Knowledge (CCKNOW) score does not reflect updated knowledge relating to inflammatory bowel disease (IBD). The aim of this study was to develop, validate, and apply a novel tool to measure disease-related knowledge in IBD patients.

METHODS

A questionnaire composed of 24 items regarding knowledge of IBD was developed: Inflammatory Bowel Disease Knowledge (IBD-KNOW). Discriminate ability of IBD-KNOW was validated in three occupational groups (14 doctors, 20 nurses, and 19 clerks). The CCKNOW and IBD-KNOW were administered to IBD patients. Factors affecting the level of IBD-related knowledge were analyzed.

RESULTS

The median Inflammatory Bowel Disease Knowledge (IBD-KNOW) score was significantly different among the three groups for validation (22 doctors, 20 nurses, and five clerks; p < 0.001). The IBD-KNOW showed excellent internal consistency (Cronbach α = 0.952) and high correlation with CCKNOW (Spearman ρ = 0.827, p = 0.01). A total of 200 IBD patients (120 Crohn's disease, 80 ulcerative colitis) completed questionnaires. Multivariate analysis showed that a higher IBDKNOW score than the median was associated with hospitalization history (odds ratio [OR], 2.625; p = 0.003), high education level (OR, 2.498; p = 0.012), and information acquired from patient organization (OR, 3.305, p = 0.035).

CONCLUSION

The IBD-KNOW demonstrated excellent test characteristics. Hospitalization history, education level, and information acquired from patient organization play an important role in correct IBD-related knowledge.

Diagnostic Performance of Multidetector Computerized Tomography in the Detection of Abdominal Complications Early and Late After Liver Transplantation: A 10-Year Experience

BACKGROUND

Multidetector computerized tomography (MDCT) is considered to be a fast noninvasive diagnostic technique for the evaluation of postoperative complications in patients with liver transplantation (LT). However, its role has not been fully established in the diagnosis for detecting complications after liver transplantation. The aim of this work was to evaluate the diagnostic performance of MDCT for detecting abdominal complications in the early and late periods after LT.

METHODS

We retrospectively enrolled 75 patients who had undergone LT from March 2006 to January 2010, followed by MDCT from March 2006 to November 2017. Patients were divided into 2 groups according to the timing after LT: within the first 3 months (early period) or ≥3 months after LT (late period). We evaluated vascular, biliary, and other complications on MDCT. Angiography, endoscopic retrograde cholangiography, and percutaneous transhepatic cholangiography were used as reference standards.

RESULTS

We initially found 77 complications in 45 patients (60.0%) with the use of MDCT. After comparison with the reference standards, 83 complications were diagnosed in 49 patients (65.3%). Forty-seven complications (34 vascular, 10 biliary, 3 other complications) were diagnosed in 33 patients (44.0%) during the early period, and 36 complications (6 vascular, 20 biliary, 10 other complications) were detected in 27 patients (36.0%) in the late period. The sensitivity, specificity, and diagnostic accuracy of MDCT for diagnosing overall complications were, respectively, 93.6%, 90.2%, and 92.0% in the early period (for vascular complications: 97.1%, 92.6%, and 94.3%,; for biliary complications: 80.0%, 100%, and 97.7%) and 77.8%, 98.1%, and 89.8% in the late period (for vascular complications: 83.3%, 100%, and 98.9%; for biliary complications: 65.0%, 98.6%, and 90.9%).

CONCLUSIONS

Although MDCT in the late period should be interpreted with caution in patients with suspected biliary complication, MDCT is a reliable diagnostic technique for the identification of early and late abdominal complications after LT.

PD-L1 and immune infiltrates are differentially expressed in distinct subgroups of gastric cancer

This study investigates the association of PD-L1 expression and immune cell infiltrates and their impact on clinical outcome, in addition to their overlap with microsatellite instability (MSI), HER2 and ATM molecular subgroups of gastric cancer (GC). PD-L1 membrane expression on tumour cells (TC) and infiltrating immune cells (IC), CD3 + T-lymphocytes, CD8+ cytotoxic T-cells, ATM and HER2 were assessed by immunohistochemistry (IHC) in the ACRG (Asian Cancer Research Group) GC cohort (N = 380). EBV status was determined using in situ hybridization and MSI status was performed using PCR and MLH1 IHC. The PD-L1 segment was associated with increased T-cell infiltrates, while the MSI-high segment was enriched for PD-L1, CD3, and CD8. Multivariate analysis confirmed PD-L1 positivity, high CD3 and high CD8 as independent prognostic factors for both disease-free survival and overall survival (all p < 0.05). Patients with MSI-high tumours had better overall survival by both univariate and multivariate analysis. The ATM-low and HER2-high subgroups differed markedly in their immune profile; the ATM-low subgroups enriched for MSI, PD-L1 positivity and CD8 + T-cells, while the HER2 segment was enriched for MSS, with no enrichment for immune markers. Hence, we demonstrate a molecular profiling approach that can divide GC into four molecular subgroups, namely ATM-low, HER2-high, PD-L1 positive and MSI-high with differing levels of immune infiltrates and prognostic significance which may help to stratify patients for response to targeted therapies.

Increased Risk of Herpes Zoster Infection in Patients With Inflammatory Bowel Diseases in Korea

BACKGROUND & AIMS

Few data are available on risk of herpes zoster (HZ) infection in Asian patients with inflammatory bowel diseases (IBD). We investigated whether patients with IBD in Korea have an increased risk of HZ and sought to identify risk factors for infection.

METHODS

We performed a nationwide population-based study and a hospital-based, nested case-control study. Using the 2009-2013 data from the Korean national health insurance claims database, we calculated incidence rates and standardized incidence ratios (SIRs) of HZ infection in patients with IBD compared with the entire Korean population. In the nested case-control study, within a hospital-based cohort, 300 patients with IBD and HZ infection were matched with 895 patients with IBD without HZ.

RESULTS

In the nationwide population-based study, the incidence rate and SIR of HZ infection in patients with IBD were 18.34/1000 person-years and 1.48 (95% CI, 1.42-1.54), respectively. The SIR for HZ infection was higher in patients with Crohn's disease than in patients with ulcerative colitis (1.90 vs 1.36; P < .001) and higher in male patients than female patients (1.63 vs 1.33; P < .001). The incidence rate of HZ increased with age (P trend < .001), whereas the SIR of HZ infection decreased with age (P trend < .001). In the nested case-control study, corticosteroid use was associated with HZ infection (for ulcerative colitis, adjusted odds ratio, 2.44; 95% CI, 1.18-5.05 and for Crohn's disease, adjusted odds ratio, 2.70; 95% CI 1.25-5.83).

CONCLUSIONS

In a population-based study in Korea, we found patients with IBD to have an increased risk for HZ infection-especially among patients who are male, younger, or have Crohn's disease. Corticosteroid use increases risk of HZ infection in patients with IBD.

Incidence of Active Tuberculosis within One Year after Tumor Necrosis Factor Inhibitor Treatment according to Latent Tuberculosis Infection Status in Patients with Inflammatory Bowel Disease

BACKGROUND

We investigated the incidence of active tuberculosis among patients with inflammatory bowel disease (IBD) treated with tumor necrosis factor (TNF) inhibitors, with or without latent tuberculosis infection (LTBI).

METHODS

The study was performed at a Korean tertiary referral center between January 2011 and June 2017. In total, 740 patients with IBD who underwent LTBI screening tests and were followed-up for ≥ 1 year after TNF inhibitor treatment initiation were enrolled. LTBI was detected on the basis of tuberculin skin test results, interferon-gamma release assay results, chest X-ray findings, and previous tuberculosis treatment history. The patients were classified into LTBI (n = 84) or non-LTBI (n = 656) group. The risk of developing tuberculosis in each group was assessed on the basis of standardized incidence ratio (SIR) and 95% confidence interval (CI) for active tuberculosis.

RESULTS

Mean patient age was 33.1 years, and patients with Crohn's disease were predominant (80.7%). Within 1 year after the initiation of TNF inhibitor treatment, 1 patient in the LTBI group (1/84; 1.2%) and 7 patients in the non-LTBI group (7/656; 1.1%) developed active tuberculosis. The overall 1-year incidence of tuberculosis among the patients was significantly higher than that among the general population (SIR, 14.0; 95% CI, 7.0-28.0), and SIR was not affected by LTBI status (LTBI group: 14.5, 95% CI, 2.0-102.6; non-LTBI group: 14.0, 95% CI, 6.7-29.4).

CONCLUSION

Patients with IBD undergoing TNF inhibitor treatment showed a higher 1-year incidence of tuberculosis than the general population irrespective of LTBI status.

Multi-Spectral Fluorescence Imaging of Colon Dysplasia InVivo Using a Multi-Spectral Endoscopy System

BACKGROUND AND STUDY AIM: To develop a molecular imaging endoscopic system that eliminates tissue autofluorescence and distinguishes multiple fluorescent markers specifically on the cancerous lesions. METHODS: Newly developed multi-spectral fluorescence endoscope device has the potential to eliminate signal interference due to autofluorescence and multiplex fluorophores in fluorescent probes. The multiplexing capability of the multi-spectral endoscope device was demonstrated in the phantom studies and multi-spectral imaging with endoscopy and macroscopy was performed to analyze fluorescence signals after administration of fluorescent probe that targets cancer in the colon. Because of the limitations in the clinical application using rigid-type small animal endoscope, we developed a flexible channel insert-type fluorescence endoscope, which was validated on the colonoscopy of dummy and porcine model. RESULTS: We measured multiple fluorescent signals simultaneously, and the fluorescence spectra were unmixed to separate the fluorescent signals of each probe, in which multiple fluorescent probes clearly revealed spectral deconvolution at the specific targeting area in the mouse colon. The positive area of fluorescence signal for each probe over the whole polyp was segmented with analyzing software, and showed distinctive patterns and significantly distinguishable values: 0.46 ± 0.04, 0.39 ± 0.08 and 0.73 ± 0.12 for HMRG, CET-553 and TRA-675 probes, respectively. The spectral unmixing was finally demonstrated in the dummy and porcine model, corroborating the targeted multi-spectral fluorescence imaging of colon dysplasia. CONCLUSION: The multi-spectral endoscopy system may allow endoscopists to clearly identify cancerous lesion that has different patterns of various target expression using multiple fluorescent probes.

Safety of simultaneous endoscopic submucosal dissection for two large colorectal neoplasias in the same patient

BACKGROUND/AIMS

Multiple large colorectal lesions requiring endoscopic submucosal dissection (ESD) are sometimes diagnosed during colonoscopy. We evaluated the feasibility and safety of ESD of two colorectal lesions in one session.

MATERIALS AND METHODS

The lesions of 16 patients who underwent two ESD procedures in a single session (double ESD group) from November 2009 to July 2014 were matched with those of 64 patients who underwent a single ESD procedure (single ESD group) based on the size and location of the lesion and presence of submucosal fibrosis.

RESULTS

The net ESD time per patient was longer in double ESD group than in single ESD group (104.0±36.2 vs. 59.1±39.2 min, p<0.001). The net ESD time per lesion tended to be shorter in double ESD group than in single ESD group (49.6±30.0 vs. 59.1±39.2 min, p=0.077). The en bloc resection and curative resection rates did not differ between double ESD and single ESD groups (93.8 % vs. 98.4%, p=0.262; 90.6 % vs. 84.4 %, p=0.534, respectively). The intra- and postprocedural bleeding rates were 12.5% and 0% in double ESD group and 15.6% and 3.1% in single ESD group, respectively. Perforation occurred in two (6.3%) in double ESD group and in six (9.4%) in single ESD group (p=0.715).

CONCLUSION

Compared with the single ESD, two simultaneous colorectal ESD procedures in a patient did not increase complications; the en bloc and curative resection rates were similar when performed a single ESD procedure and two simultaneous ESD procedures.

Switching to tenofovir vs continuing entecavir for hepatitis B virus with partial virologic response to entecavir: a randomized controlled trial

Entecavir 0.5 mg (ETV) is widely used among treatment-naïve chronic hepatitis B (CHB) patients. However, 10%-30% of patients show partial virologic response (PVR) to the drug. If the hepatitis B virus (HBV) continues to replicate, the underlying liver disease may progress. Herein, we compared the efficacy of switching to tenofovir disoproxil fumarate (TDF) with that of continuing ETV in CHB patients with PVR to ETV. This was an open-label randomized controlled trial including CHB patients who had been receiving 0.5 mg of ETV for >12 months, but who still had detectable HBV DNA levels of >60 IU/mL without known resistance to ETV. Sixty patients were enrolled and 45 qualified for the study: Twenty-two patients were randomly assigned into the TDF group and 23 into the ETV group. After 12 months of treatment, the virologic response rate (HBV DNA <20 IU/mL) was significantly higher in the TDF group than in the ETV group, as measured using per-protocol analysis (55% vs 20%; P = .022) and intention-to-treat analysis (50% vs 17.4%; P = .020). The reduction in HBV DNA was greater (-1.13 vs -0.67 log₁₀ IU/mL; P = .024), and the mean HBV DNA level was lower (1.54 vs 2.01 log₁₀ IU/mL; P = .011) in the TDF group than in the ETV group. In conclusion, to achieve optimal response in CHB patients with PVR to ETV, switching to TDF would be a better strategy than continuing ETV. Appropriate modification of therapy would further improve the outcome of chronic HBV infection.

A high-resolution anorectal manometry parameter based on integrated pressurized volume: A study based on 204 male patients with constipation and 26 controls

BACKGROUND

Conventional anorectal manometric parameters based on linear waves cannot properly predict balloon expulsion (BE) time. We aimed to determine the correlation between integrated pressurized volume (IPV) parameters during simulated evacuation (SE) and BE time in healthy individuals and constipated patients and to assess the correlation between each parameter and symptoms.

METHODS

A total of 230 male participants (including 26 healthy volunteers and 204 chronically constipated patients) underwent high-resolution anorectal manometry (HRAM) and BE tests. The IPV was calculated by multiplying the amplitude, distance, and time from the HRAM profile. Receiver operating characteristic curve (ROC) analysis and partial least square regression (PLSR) were performed.

KEY RESULTS

ROC analysis indicated that the IPV ratio between the upper 1 cm and lower 4 cm of the anal canal was more effective for predicting BE time (area under the curve [AUC]: 0.74, 95% confidence interval [CI]: 0.67-0.80, P < .01) than the conventional anorectal parameters, including defecation index and rectoanal gradient (AUC: 0.60, 95% CI: 0.52-0.67, P = .01). PLSR analysis of a linear combination of IPV parameters yielded an AUC of 0.79. Moreover, the IPV ratio showed a greater clinical correlation with patient symptoms than conventional parameters.

CONCLUSIONS AND INFERENCES

The IPV parameters and the combination of IPV parameters via PLSR were more significantly correlated with BE time than the conventional parameters. Thus, this study presents a useful diagnostic tool for the evaluation of pathophysiologic abnormalities in dyssynergic defecation using IPV and BE time.

An Intergenic Variant rs9268877 Between HLA-DRA and HLA-DRB Contributes to the Clinical Course and Long-term Outcome of Ulcerative Colitis

BACKGROUND AND AIMS

The genetic contribution to the prognosis of ulcerative colitis [UC] is poorly understood, and most currently known susceptibility loci are not associated with prognosis. To identify genetic variants influencing the prognosis of UC, we performed an Immunochip-based study using an extreme phenotype approach.

METHODS

Based on the finding that the only association, Pdiscovery-meta <1 × 10-4, was located in the human leukocyte antigen [HLA], we focused our analyses on the HLA region. We performed the analysis using HLA imputation data from three independent discovery cohorts of 607 UC patients [243 poor-prognosis and 364 good-prognosis], followed by replication in 274 UC patients [145 poor-prognosis and 129 good-prognosis].

RESULTS

We found that rs9268877, located between HLA-DRA and HLA-DRB, was associated with poor-prognosis of UC at genome-wide significance (odds ratio [ORdiscovery] = 1.82; ORreplication = 1.55; ORcombined-meta = 1.72, pcombined-meta = 1.04 × 10-8), with effect size [OR] increasing incrementally according to worsening of prognosis in each of the three independent discovery cohorts and the replication cohort. However, rs9268877 showed no association with UC susceptibility [ORcombined-meta = 1.07, pcombined-meta = 0.135]; rs9268877 influenced 30-year clinical outcomes, and the presence of the rs9268877 risk allele had a sensitivity of 80.0% and specificity of 38.1% for colectomy.

CONCLUSIONS

Our results provide new insights into prognosis-associated genetic variation in UC, which appears to be distinct from the genetic contribution to disease susceptibility. These findings could be useful in identifying poor-prognosis patients who might benefit from early aggressive therapy.

Relation of Enteric α-Synuclein to Gastrointestinal Dysfunction in Patients With Parkinson's Disease and in Neurologically Intact Subjects

Background/Aims

α-Synucleinopathy in the brain is the neuropathological hallmark of Parkinson’s disease (PD). However, the functional impact of α-synucleinopathy in the enteric nervous system remains unknown. We aim to evaluate the association between gastrointestinal (GI) dysfunction and α-synuclein (αSYN) pathology in the stomach and colon of PD patients and controls, as well as to investigate the association between the αSYN pathology in GI tract and future PD risk.

Methods

A total of 35 PD patients and 52 neurologically intact subjects were enrolled in this study. Endoscopic biopsies were performed, and then immunohistochemical staining for αSYN was performed. All subjects completed the validated Rome III questionnaire for the assessment of GI symptoms. The association between GI symptoms and the αSYN pathology in GI mucosa was evaluated. Incident PD cases were assessed during a median follow-up of 46 months.

Results

The proportion of self-reported constipation and functional constipation through the Rome III questionnaire was significantly higher in PD patients than in controls (P < 0.001 and P = 0.015). However, no significant association was found between the αSYN pathology in the stomach and colon mucosa and constipation, as well as other GI symptoms including dyspepsia symptoms and abdominal discomfort or pain, regardless of the presence or absence of clinical PD (P > 0.05). No incident PD cases were diagnosed during study period.

Conclusions

Our present study suggests that the deposition of αSYN in the mucosal enteric nervous system may not be reflected by functional impairment of the affected segment of the gut.

Incidence and Risk Factor Analysis of Thromboembolic Events in East Asian Patients With Inflammatory Bowel Disease, a Multinational Collaborative Study

BACKGROUND

Inflammatory bowel disease (IBD) increases the risk of venous thromboembolism (VTE) events. However, the incidence and necessity of prophylaxis for VTE in Asian IBD patients is unknown. We examined the incidence of VTE in East Asian IBD patients and analyze the possible risk factors.

METHODS

We conducted a multinational retrospective study of 2562 hospitalized IBD patients from 2010 to 2015. Moreover, a nationwide cohort study from 2001 to 2013 from the Taiwan National Health Insurance Research Database (NHIRD) was conducted to analyze the incidence rate of VTE in IBD and non-IBD patients.

RESULTS

In the hospitalized cohort, 24 IBD patients [17 ulcerative colitis (UC) and 7 Crohn's disease (CD)] received a VTE diagnosis (0.9%). These patients had a higher proportion of extensive UC (P = 0.04), penetrating-type CD (P < 0.01), and bowel operation history (P = 0.01). VTE was associated with low hemoglobin (P < 0.01), low platelet (P < 0.01), and low albumin (P < 0.01) levels. For the nation-wide cohort study, 3178 IBD patients and 31,780 age- and sex-matched non-IBD patients were analyzed. The average incidence rate was 1.15 per 1000 person-years in the IBD cohort and 0.51 in the non-IBD cohort. The relative risk was 2.27 (95% CI, 1.99-2.60).

CONCLUSIONS

East Asian IBD patients carry a 2-fold increased risk of VTE than the general population. The incidence of VTE in the East Asian IBD patients is still lower than that in Western countries. Therefore, close monitoring rather than routine prophylaxis of VTE in East Asian IBD patients is recommended.

Prone positioning before extracorporeal membrane oxygenation for severe acute respiratory distress syndrome: A retrospective multicenter study

OBJECTIVE

To evaluate the clinical outcomes of patients with severe acute respiratory distress syndrome (ARDS) subjected to prone positioning before extracorporeal membrane oxygenation (ECMO).

DESIGN

A retrospective analysis of a multicenter cohort was carried out.

SETTING

Patients admitted to the Intensive Care Units of 11 hospitals in Korea.

PATIENTS

Patients were divided into those who underwent prone positioning before ECMO (n=28) and those who did not (n=34).

INTERVENTIONS

None.

VARIABLES OF INTEREST

Thirty-day mortality, ECMO weaning failure rate, mechanical ventilation weaning success rate, mechanical ventilation-free days at day 60.

RESULTS

The prone group had lower median peak inspiratory pressure and lower median dynamic driving pressure before ECMO. Thirty-day mortality was 21% in the prone group and 41% in the non-prone group (p=0.098). The prone group also showed a lower ECMO weaning failure rate, and a higher mechanical ventilation weaning success rate and more mechanical ventilation-free days at day 60. In the non-prone group, median dynamic compliance marginally decreased shortly after ECMO, but no significant change was observed in the prone group.

CONCLUSIONS

Prone positioning before ECMO was not associated to increased mortality and tended to exert a protective effect.

Pasture flock chicken cecal microbiome responses to prebiotics and plum fiber feed amendments

When prebiotics and other fermentation substrates are delivered to animals as feed supplements, the typical goal is to improve weight gain and feed conversion. In this work, we examined pasture flock chicken cecal contents using next generation sequencing (NGS) to identify and understand the composition of the microbiome when prebiotics and fermentation substrates were supplemented. We generated 16S rRNA sequencing data for 120 separate cecal samples from groups of chickens receiving one of 3 prebiotics or fiber feed additives. The data indicated that respective feed additives enrich for specific bacterial community members and modulate the diversity of the microbiome. We applied synthetic learning in microbial ecology (SLiME) analysis to interpret 16S rRNA microbial community data and identify specific bacterial operational taxonomic units (OTU) that are predictive of the particular feed additives used in these experiments. The results suggest that feed can influence microbiome composition in a predictable way, and thus diet may have indirect effects on weight gain and feed conversion through the microbiome.

Effects of feeding Original XPC™ to broilers with a live coccidiosis-vaccine under industry conditions: Part 1. Growth performance and Salmonella inhibition

Supplementation of poultry diets with Diamond V Original XPC™ (XPC) has been proposed as a means to ameliorate the commonly observed loss of appetite and depression of growth in birds given a live coccidiosis vaccine. A study was conducted to compare the effects on bird performance of a live coccidiosis vaccine in broilers, with and without the dietary inclusion of XPC (1.25 g/kg). Ross 708 male broilers (n = 1,280) were allocated to one of 4 feed treatments: cocci-vaccine (T1), cocci-vaccine + XPC (T2), cocci-vaccine + salinomycin in the grower diet only, (T3), and cocci-vaccine + salinomycin in the grower diet + XPC (T4). Birds consuming diets containing XPC (T2 and T4) and salinomycin (T3) exhibited increased (P < 0.05) feed intake and significantly heavier body weights at 28 d (1.70, 1.74, and 1.67 kg, respectively) and 42 d (3.29, 3.31, and 3.26 kg, respectively). Feed conversion ratio at 28 d was improved (P < 0.05) by adding XPC to diets (T2: 1.47 and T4: 1.44) compared to control diets (T1: 1.50 and T3: 1.47). Salmonella prevalence determined via selective media indicated the inclusion of XPC in the diet resulted in a significant reduction of Salmonella when compared to treatments lacking XPC. Molecular confirmation of Salmonella species indicated S. Kentucky to be present in 38 of the 39 positive samples. Results revealed the ability of XPC in reducing the prevalence of Salmonella. Results from this study also suggest that XPC could be used in conjunction with a live coccidiosis-vaccine to increase growth rate and improve feed conversion of broilers. However, further work is needed to delineate more specific effects directly attributable to XPC.

PSP1, a Phosphatidylserine-Recognizing Peptide, Is Useful for Visualizing Radiation-Induced Apoptosis in Colorectal Cancer In Vitro and In Vivo

Accurate and timely visualization of apoptotic status in response to radiation is necessary for deciding whether to continue radiation or change to another mode of treatment. This is especially critical in patients with colorectal cancer, which requires a delicate combination of surgery, radiation, and chemotherapy in order to achieve optimal outcome. In this study, we investigated the potential of phosphatidylserine-recognizing peptide 1 (PSP1) as an apoptosis-targeting probe, which identifies phosphatidylserine on cell surfaces. We first screened colon cancer cell lines for their sensitivity to radiation and selected two cell lines: HCT116 and HT29. Cell binding assay using fluorescence-activated cell sorting and optical imaging showed that HCT116 cells had better binding to PSP1 than HT29 cells. Thus, mouse xenograft model using HCT116 cells was generated and was topically irradiated with either single or fractionated dose of radiation followed by systemic administration of PSP1 for subsequent molecular optical imaging. We confirmed that the PSP1 probe was selectively bound to apoptosis-induced tumor in a radiation dose-dependent manner. We also observed that fractionated radiation regimen, which is recently being used in clinical situation, was more effective in inducing tumor apoptosis than corresponding single-dose radiation treatment. We then evaluated the correlation between tumor targeting of PSP1 and suppression effect of tumor development and found that tumor volume and fluorescence intensity were correlated before (correlation coefficient r² = 0.534) and after (r² = 0.848) radiation therapy. Our study shows that PSP1 peptide is an efficient index probe for deciding "go or no-go" for radiation therapy in colorectal cancer.

Molecular-based identification and detection of Salmonella in food production systems: current perspectives

Salmonella remains a prominent cause of foodborne illnesses and can originate from a wide range of food products. Given the continued presence of pathogenic Salmonella in food production systems, there is a consistent need to improve identification and detection methods that can identify this pathogen at all stages in food systems. Methods for subtyping have evolved over the years, and the introduction of whole genome sequencing and advancements in PCR technologies have greatly improved the resolution for differentiating strains within a particular serovar. This, in turn, has led to the continued improvement in Salmonella detection technologies for utilization in food production systems. In this review, the focus will be on recent advancements in these technologies, as well as potential issues associated with the application of these tools in food production. In addition, the recent and emerging research developments on Salmonella detection and identification methodologies and their potential application in food production systems will be discussed.

Magnetic resonance tumour regression grade and pathological correlates in patients with rectal cancer

BACKGROUND

Evidence to support the specific use of magnetic resonance tumour regression grade (mrTRG) is inadequate. The aim of this study was to investigate the pathological characteristics of mrTRG after chemoradiotherapy (CRT) for rectal cancer and the implications for surgery.

METHODS

Patients undergoing long-course CRT (45-50 Gy plus a booster dose of 4-6 Gy) for mid or low rectal cancer (cT3-4 or cN+ without metastasis) between 2011 and 2015 who had post-CRT rectal MRI before surgery were included retrospectively. Three board-certified experienced radiologists assessed mrTRG. mrTRG was correlated with pathological tumour regression grade (pTRG), ypT and ypN. In a subgroup of patients with mrTRG1-2 and no tumour spread (such as nodal metastasis) on MRI, the projected rate of completion total mesorectal excision (TME) if they underwent transanal excision (TAE) and had a ypT status of ypT2 or higher was estimated, and recurrence-free survival was calculated according to the operation (TME or TAE) that patients had actually received.

RESULTS

Some 439 patients (290 men and 149 women of mean(s.d.) age 62·2(11·4) years) were analysed. The accuracy of mrTRG1 for predicting pTRG1 was 61 per cent (40 of 66), and that for ypT1 or less was 74 per cent (49 of 66). For mrTRG2, these values were 22·3 per cent (25 of 112) and 36·6 per cent (41 of 112) respectively. Patients with mrTRG1 and mrTRG2 without tumour spread were ypN+ in 3 per cent (1 of 29) and 16 per cent (8 of 50) respectively. Assuming mrTRG1 or mrTRG1-2 with no tumour spread on post-CRT MRI as the criteria for TAE, the projected completion TME rate was 26 per cent (11 of 43) and 41·0 per cent (41 of 100) respectively. For the 100 patients with mrTRG1-2 and no tumour spread, recurrence-free survival did not differ significantly between TME (79 patients) and TAE (21) (adjusted hazard ratio 1·86, 95 per cent c.i. 0·42 to 8·18).

CONCLUSION

Patients with mrTRG1 without tumour spread may be suitable for TAE.

Recurrence rate of lateral margin-positive cases after en bloc endoscopic submucosal dissection of colorectal neoplasia

PURPOSE

We aimed to evaluate the recurrence rate of colorectal neoplasia showing histologic lateral margin involvement after en bloc endoscopic submucosal dissection (ESD).

METHODS

We reviewed 527 colorectal lesions that were removed by en bloc ESD from 2005 to 2013 and followed by endoscopy. Based on the postprocedural pathologic reports, the lesions were categorized as follows: lesions with clear deep and positive lateral margins (n = 63) and lesions with R0 resection (n = 299).

RESULTS

The tumor size was 45.7 ± 21.1 mm in the lateral margin-positive group and 30.6 ± 15.1 in the R0 group (P < 0.001). Procedure time was longer in the lateral margin-positive group than in the R0 group (94.3 ± 75.1 vs. 54.1 ± 48.9 min; P < 0.001). Lateral margin positivity was associated with ESD time ≥ 120 min in the multivariate analysis. Compared with 0-I morphology, LST-G was significantly associated with the lateral margin positivity. The volume of ESD experience in endoscopists may also be associated with the lateral margin positivity. Histologic reassessment of the specimen suggested that 32.2% of lateral margin-positive cases based on the initial pathology report were false-positive lateral margin involvement. The 5-year cumulative recurrence rate was 0.6% in the R0 group and 5% in the margin-positive group (P = 0.198).

CONCLUSIONS

The local recurrence rate was not higher in lateral margin-positive cases than in R0 resection cases if the colorectal epithelial neoplasia was removed in an en bloc manner using ESD. Meticulous pathologic interpretation may reduce unnecessarily frequent surveillance after en bloc ESD.

Effect of relative humidity on inactivation of foodborne pathogens using chlorine dioxide gas and its residues on tomatoes

The effect of relative humidity (RH) on the antimicrobial efficacy of chlorine dioxide (ClO₂ ) gas against foodborne pathogens on tomatoes was evaluated. Also, levels of ClO₂ residues on tomatoes after exposure to ClO₂ gas under different RH conditions were measured to determine the quantity of solubilized ClO₂ gas on tomato surfaces. Escherichia coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes were inoculated on tomatoes and exposed to ClO₂ gas (5, 10, 20 and 30 ppmv) under different RH conditions (50, 70 and 90%). As ClO₂ gas concentration and treatment time increased, significant differences (P < 0·05) were observed between inactivation levels under different RH conditions. Exposure to 30 ppmv of ClO₂ gas (50% RH) for 20 min resulted in 1·22-1·52 log reductions of the three foodborne pathogens. Levels of the three foodborne pathogens were reduced to below the detection limit (0·48 log CFU per cm² ) within 15 min when exposed to 30 ppmv of ClO₂ gas at 70% RH and within 10 min at 90% RH. At a given ClO₂ gas concentration, ClO₂ residues on tomatoes significantly (P < 0·05) increased with increasing RH, and there were close correlations between log reductions of pathogens and ClO₂ residues on tomatoes.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study reported on the correlation between the amount of ClO₂ residues on produce surfaces and the level of inactivation of pathogens after ClO₂ gas treatment. Variations in RH have great effect on the solubilization of ClO₂ gas on tomato surfaces considering that ClO₂ residues on tomatoes increased with increasing RH. Also, the amount of ClO₂ residues on tomatoes is positively correlated with the level of inactivation of pathogens. The results of this study provide insights for predicting inactivation patterns of foodborne pathogens by ClO₂ gas for practical application by the fresh produce industry.

Immunochip Meta-Analysis of Inflammatory Bowel Disease Identifies Three Novel Loci and Four Novel Associations in Previously Reported Loci

BACKGROUND AND AIMS

Recent meta-analysis of genome-wide association studies have identified over 241 inflammatory bowel disease susceptibility loci. However, the known variants only account for a fraction of inflammatory bowel disease heritability. To identify additional susceptibility loci, we performed a trans-ethnic meta-analysis as well as an Asian-specific meta-analysis, using all published Immunochip association results of inflammatory bowel disease.

METHODS

An inverse-variance fixed-effects meta-analysis was carried out across Korean and East Asian Immunochip datasets of 4156 cases and 4904 controls [Asian ancestry]. A trans-ethnic meta-analysis of inflammatory bowel disease was performed together with the European datasets of 38 155 cases and 48 485 controls genotyped on the immunochip using a Bayesian approach, Meta-Analysis of Trans-ethnic Association studies [MANTRA].

RESULTS

We identified seven novel associations, including three novel susceptibility loci at MYO10-BASP1, PPP2R3C/KIAA0391/PSMA6/NFKB1A and LRRK1 as well as four novel secondary associations within previously known loci at NCF4, TSPAN32, CIITA and VANGL2. The new loci further implicate alterations in B cell biology in Crohn's disease pathogenesis. The effects of five loci were universal across European and Asian ancestries, whereas the NCF4 and CIITA loci showed significant heterogeneity between European and East Asian populations. In addition, 103 previously known IBD loci showed supporting evidence of association with nominal significance [p < 0.05] in Asians.

CONCLUSIONS

Our findings of new loci not previously associated with IBD support the importance of studying inflammatory bowel disease genetics in diverse populations.

Prevalence of Fructose Malabsorption in Patients With Irritable Bowel Syndrome After Excluding Small Intestinal Bacterial Overgrowth

Background/Aims

Fructose malabsorption (FM) mimics symptoms of irritable bowel syndrome (IBS), and its prevalence has increased. Diagnosing FM in IBS is challenging because of its overlap with small intestinal bacterial overgrowth (SIBO). We assessed the prevalence of FM by comparing patients with IBS with asymptomatic control individuals after excluding SIBO using the glucose hydrogen breath test (HBT).

Methods

Patients diagnosed with IBS and asymptomatic control individuals were enrolled prospectively. Dietary habits were assessed with the Food Frequency Questionnaire. After excluding SIBO, participants underwent HBTs with both 15 g and 25 g of fructose.

Results

Thirty-five patients with IBS and 35 age- and sex-matched asymptomatic control individuals were enrolled. The 15-g fructose HBT yielded positive results in 7 of the 35 (20.0%) patients with IBS and in 2 of 35 (5.7%) controls (P = 0.070). The 25-g fructose HBT was positive in 16 of the 35 (45.7%) patients with IBS and in 8 of the 35 (22.9%) controls (P = 0.040). Analysis of the Food Frequency Questionnaire responses showed no significant differences between the 2 groups in dietary intake, although patients with IBS showed a significantly higher mean fiber intake than controls (21.24 ± 11.35 g vs 15.87 ± 7.07 g, respectively, P = 0.040).

Conclusions

The 25-g fructose HBT identified FM in a significantly higher percentage of SIBO-negative patients with IBS than in asymptomatic control individuals, suggesting that FM may correlate with IBS. Education regarding dietary control of foods containing fructose may be useful for the management of patients with IBS.

Is Clostridium difficile infection a real threat in patients with ulcerative colitis? A prospective, multicenter study in Korea

Background/Aims

Clostridium difficile infection (CDI) has been reported to be a cause of flare-ups in patients with ulcerative colitis (UC). We evaluated the prevalence and clinical outcomes of CDI in patients with UC hospitalized for flare-ups.

Methods

This was a prospective, multicenter study including 7 academic teaching hospitals in Korea. All consecutive patients with UC admitted for disease flare-up were enrolled. We detected the presence of CDI by using enzyme immunoassay, real-time polymerase chain reaction (RT-PCR) for toxin genes, and sigmoidoscopy.

Results

Eighty-one consecutive patients with UC were enrolled from January 2014 to December 2015. Among 81 patients, 8 (9.9%) were diagnosed with CDI. Most of the cases were identified by RT-PCR. Enzyme immunoassay was positive in 3 of 8 patients, and only 1 had typical endoscopic findings of pseudomembranous colitis. There were no differences in demographic data, length of hospital stay, or colectomy rate between patients with and without CDI.

Conclusions

CDI was not a rare cause of flare-up in patients with UC in Korea. However, CDI did not appear to affect the course of UC flare-up in Korean patients. RT-PCR was sensitive in detecting CDI and can be considered a diagnostic tool in patients with UC flare-up.

A case of ulcerative colitis presenting with cerebral venous thrombosis

Patients with inflammatory bowel disease (IBD) have been reported to have an increased risk of thromboembolism. Cerebral venous thrombosis (CVT) is a rare but serious extraintestinal manifestation of IBD. Due to its highly variable manifestation and low incidence, CVT is not usually readily recognized by physicians. Herein, we report a case of a 35-year-old male presenting with CVT associated with ulcerative colitis (UC). The patient was admitted with chief complaints of bloody diarrhea that had started 3 days prior. Sigmoidoscopy showed hyperemic and edematous mucosa, friability, and shallow ulcers from the sigmoid colon to the rectum suggestive of IBD. Three days later, the patient started complaining of a headache, and gradually developed a decreased level of consciousness. Magnetic resonance imaging of the brain revealed CVT with hemorrhagic infarctions. An angiogram was obtained to evaluate the extent of CVT, and anticoagulation therapy was initiated with intravenous heparin. During hospitalization, he was diagnosed with UC and treated with 5-aminosalicylic acid. After discharge, the patient was recovered without neurological deficit, and remission of UC was also obtained. The presence of headache or acute worsening of neurological status in a patient with IBD should alert the health professionals about the possibility of CVT.

Influence of human parathyroid hormone during orthodontic tooth movement and relapse in the osteoporotic rat model: A preliminary study

OBJECTIVE

To investigate the effects of parathyroid hormone (PTH) on tooth movement in ovariectomized (OVX) rats by comparing the tooth movement distance and relapse and by examining the alveolar bone microstructure.

MATERIALS AND METHODS

Thirty 8-week-old female rats were classified into 3 groups: sham-operated, OVX and ovariectomized rats injected with PTH (PTH). Eight weeks later, a closed-coil spring appliance was placed between the maxillary incisor and the first molar and then activated with 50 cN of force. During tooth movement, 30 μg/kg of PTH was administered 3 times per week in the PTH group. Tooth movement distances were measured weekly. Five rats in each group were killed after 3 weeks for microcomputerized tomographic analysis, and the remaining 5 rats in each group were killed at an additional 3 weeks after the removal of the appliance to measure relapsed distance.

RESULTS

The OVX group showed significantly greater tooth movement compared to those in the other 2 groups at 2 and 3 weeks (P < .05). The relapse distance and relapse percentage for the OVX group were higher; however, it did not differ significantly from the PTH group. On micro-CT analysis, bone volume/tissue volume ratio and bone mineral density in the PTH group were significantly greater than in the OVX group (P < .05).

CONCLUSIONS

Application of PTH did not promote tooth movement in OVX rat, however, did lead to decrease in relapse tendency. Therefore, the application of PTH during orthodontic treatment of patients with osteoporosis should be carefully considered.

Association of CDKN2A/CDKN2B with inflammatory bowel disease in Koreans

BACKGROUND AND AIM

CDKN2A/CDKN2B locus on 9p21 is reported to be associated with various diseases, including cancer and cardiovascular and inflammatory diseases. Significant downregulation of CDKN2B-AS1 in inflamed colon tissue of inflammatory bowel disease (IBD) cases was reported in Europeans. This study aimed to confirm the suggestive association of CDKN2A/CDKN2B with IBD identified in our recent genome-wide association study (GWAS).

METHODS

We examined the association of CDKN2A/CDKN2B locus with IBD in an additional sample of 574 IBD cases and 542 controls, totaling 4068 cases and 8074 controls. In silico study was performed at various levels for functional annotation of the causal variant. Co-localization of the GWAS association signals and the corresponding expression quantitative trait loci in IBD-related tissues was evaluated using eCAVIAR.

RESULTS

An expanded GWAS showed genome-wide significant association of rs3731257 at 9p21 with IBD (odds ratio = 1.17, 95% confidence interval = 1.12-1.22, P_combined  = 5.68 × 10^-9 ) and Crohn's disease (odds ratio = 1.22, 95% confidence interval = 1.15-1.28, P_combined  = 8.85 × 10^-9 ) in the Korean population. Co-localization study suggested that both CDKN2B-AS1 and CDKN2A might be functionally associated with the locus in the small intestine.

CONCLUSIONS

rs3731257 in CDKN2A/CDKN2B is an IBD-susceptible locus in Koreans, with a suggestive role for small intestine-specific gene regulation. Our findings suggested that alterations of the CDKN2A/CDKN2B locus could affect the pathophysiology of IBD.

Clinical characteristics and long-term prognosis of elderly-onset Crohn's disease

OBJECTIVES

This study aimed to evaluate the clinical characteristics and clinical course of Asian elderly-onset Crohn's disease (EOCD) patients in a large well-defined cohort of South Korean IBD patients.

MATERIALS AND METHODS

From the Asan inflammatory bowel disease registry, we identified 29 EOCD patients (diagnosed with CD in age of 60 years or over) out of 2989 CD patients (1.0%). After excluding two patients with unclear data, 27 EOCD were matched with 108 young-onset CD (YOCD) and 108 middle age-onset CD (MOCD) for the interval from symptom onset to diagnosis (±3 years) and follow-up duration (±3 years).

RESULTS

Females were predominant in the EOCD group (59.3%) compared to MOCD (31.5%) and YOCD (29.6%) groups (p = .012). In EOCD group, terminal ileal location was the most common (63.0%) at diagnosis, whereas ileocolonic location in other groups (57.4% in MOCD and 78.7% in YOCD, respectively) (p < .001). Patients with perianal fistula at CD diagnosis were less common (14.8% in EOCD vs. 28.7% in MOCD vs. 49.1% in YOCD, p < .001). During follow-up, thiopurines were used less frequently in the EOCD group (48.1% in EOCD vs. 87.0% in MOCD vs. 89.8% in YOCD, p < .001), but the risk for intestinal resection was comparable among three groups (p = .583).

CONCLUSIONS

EOCD may have a better clinical course than MOCD and YOCD, as demonstrated by the similar risk for intestinal resection despite the less frequent use of thiopurines.

A case of ulcerative colitis presenting with cerebral venous thrombosis

Patients with inflammatory bowel disease (IBD) have been reported to have an increased risk of thromboembolism. Cerebral venous thrombosis (CVT) is a rare but serious extraintestinal manifestation of IBD. Due to its highly variable manifestation and low incidence, CVT is not usually readily recognized by physicians. Herein, we report a case of a 35-year-old male presenting with CVT associated with ulcerative colitis (UC). The patient was admitted with chief complaints of bloody diarrhea that had started 3 days prior. Sigmoidoscopy showed hyperemic and edematous mucosa, friability, and shallow ulcers from the sigmoid colon to the rectum suggestive of IBD. Three days later, the patient started complaining of a headache, and gradually developed a decreased level of consciousness. Magnetic resonance imaging of the brain revealed CVT with hemorrhagic infarctions. An angiogram was obtained to evaluate the extent of CVT, and anticoagulation therapy was initiated with intravenous heparin. During hospitalization, he was diagnosed with UC and treated with 5-aminosalicylic acid. After discharge, the patient was recovered without neurological deficit, and remission of UC was also obtained. The presence of headache or acute worsening of neurological status in a patient with IBD should alert the health professionals about the possibility of CVT.

Disability due to Inflammatory Bowel Disease Is Correlated with Drug Compliance, Disease Activity, and Quality of Life

Background/Aims

The inflammatory bowel disease disability index (IBD-DI) was recently developed for IBD to assess the functional consequences and disease burden. We applied the IBD-DI to a Korean population and identified predictive factors influencing IBD-related disability.

Methods

Between March and August 2015, 322 consecutive patients with IBD were prospectively recruited. Patients completed the IBD-DI questionnaire and Crohn’s and Ulcerative Colitis Questionnaire (CUCQ-8) for assessing quality of life. We examined the relationships between IBD-DI and disease activity or quality of life and analyzed predictive factors in Korean IBD patients.

Results

Enrolled patients completed both questionnaires. Total IBD-DI was correlated with CUCQ-8 scores in both ulcerative colitis (r=0.636, p<0.001) and Crohn’s disease (r=0.711, p<0.001). Total IBD-DI was also correlated with disease activity in both ulcerative colitis (r= −0.224, p=0.003) and Crohn’s disease (r= −0.307, p<0.001). Better drug compliance was associated with lower disability (p=0.001) and higher quality of life (p=0.003).

Conclusions

Disability from IBD was correlated with disease activity and poor quality of life. Better drug compliance was associated with lower disability and higher quality of life. Our findings indicate that physicians should emphasize the importance of medication compliance for IBD patients.

Tick microbial communities within enriched extracts of Amblyomma maculatum

Our objective of this study was to explore the bacterial microbiome in fresh or fresh-frozen adult Amblyomma maculatum (Gulf Coast ticks) using extracts enriched for microbial DNA. We collected 100 questing adult A. maculatum, surface disinfected them, and extracted DNA from individual ticks collected the same day or after storage at -80 °C. Because only extracts with microbial DNA concentrations above 2 ng/μL were considered suitable for individual analysis, we expected fewer samples to meet these requirements. Of individual ticks extracted, 48 extracts met this minimum concentration. We pooled 20 additional extracts that had lower concentrations to obtain seven additional pools that met the minimum DNA concentration. Libraries created from these 55 samples were sequenced using an Illumina MiSeq platform, and data sets were analyzed using QIIME to identify relative abundance of microorganisms by phylum down to genus levels. Proteobacteria were in greatest abundance, followed by Actinobacteria, Firmicutes, and Bacteroidetes, at levels between 1.9% and 6.4% average relative abundance. Consistent with the Francisella-like endosymbiont known to be present in A. maculatum, the genus Francisella was detected at highest relative abundance (72.9%; SE 0.02%) for all samples. Among the top ten genera identified (relative abundance ≥ 0.5%) were potential extraction kit contaminants, Sphingomonas and Methylobacterium, the soil bacterium Actinomycetospora, and the known A. maculatum-associated genus, Rickettsia. Four samples had Rickettsia at greater than 1% relative abundance, while nine additional samples had Rickettsia at low (0.01-0.04%) relative abundance. In this study, we used the entire microbe-enriched DNA extract for whole ticks for microbiome analysis. A direct comparison of the microbiome in microbe-enriched DNA and total genomic DNA extracts from halves of the same tick would be useful to determine the utility of this extraction method in this system. We anticipate that future tick microbiome studies will be valuable to explore the influence of microbial diversity on pathogen maintenance and transmission, and to evaluate niche-specific microbiomes within individual tick tissues.

Abstract P1-01-02: Targeting PTK6 to treat mesenchymal triple negative breast cancer

Background/Rational: Patients with triple negative breast cancers (TNBC) have limited therapeutic options beyond conventional chemotherapy. Unfortunately, high-risk for metastatic recurrence and chemotherapy resistant diseases cause the worst 5-year survival rate in patients with TNBC, which have been significant clinical challenges. Novel therapeutic targets or strategies to combat metastasis and chemotherapy resistance are necessary to improve quality of life and outcomes for patients with high risk TNBC. Epithelial-to-mesenchymal transition (EMT) and anoikis resistance are processes recognized as contributing to enhanced metastatic potential and treatment resistance. A subset of TNBC exhibits mesenchymal gene signatures and phenotypes that may be associated with high metastatic recurrence, chemotherapy resistance and immunosuppression. In a functional genomic screen, we identified several candidates as novel regulators of EMT and anoikis sensitivity of TNBC cells. We have focused on roles of one highly validated candidate, protein tyrosine kinase 6 (PTK6) on EMT, anoikis resistance and metastatic capacity in TNBC. Methods: We analyzed expression of PTK6 and mesenchymal markers in patient triple negative tumors by immunohistochemistry. In breast epithelial and TNBC cell lines, the levels of PTK6 were genetically modulated, and determined effects on growth, migration and EMT. In vivo mouse models were used to show effects of PTK6 inhibition on metastatic capacity of TNBC cells. We have also validated effects of PTK6 specific small molecule inhibitor on TNBC growth and metastases. In order to dissect specific mechanisms by which PTK6 inhibition regulates TNBC mesenchymal phenotypes, we used a siRNA library screening and identified novel E3 ligases that may be responsible for PTK6 inhibition-induced EMT regulation. Results: Overexpression of PTK6 in MCF10A cells is sufficient to promote an EMT; promotes migration, suppresses epithelial markers (E-cadherin/claudin-1) and increases mesenchymal markers (N-cadherin and fibronectin). In contrast, PTK6 inhibition either PTK6 shRNAs or treatment with a specific kinase inhibitor enhances E-cadherin expression and suppresses migration, anoikis resistance and lung colonization of TNBC cells. PTK6-dependent E-cadherin regulation is specifically dependent on levels of SNAIL, a transcriptional repressor that is associated with poor TNBC patient prognosis. SNAIL down-regulation by PTK6 inhibition is directly responsible for the modulation of anoikis sensitivity, which is in turn causally linked to lung colonization potential. PTK6 inhibition promotes the proteasome-dependent degradation of SNAIL via a novel mechanism independent of GSK3β/β-TRCP pathway or Fbox E3ligases (FBXO5, FBXO11, FBXL14) that are known to regulate SNAIL ubiquitination. Using a siRNA library screening approach, we identified novel E3 ligase candidates that may be responsible for SNAIL ubiquitination and degradation downstream of PTK6 inhibition. Conclusion/Future direction: PTK6 is a representative novel regulator of EMT and anoikis resistance that can be targeted to prevent metastases of TNBC. Modulation of mesenchymal phenotypes of TNBC cells may be able to regulate chemotherapy resistance and/or immunosuppressive microenvironment.

Citation Format: Ito K, Park SH, Nayak A, Byerly J, Irie HY. Targeting PTK6 to treat mesenchymal triple negative breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-01-02.

Endoscopic features and clinical outcomes of colorectal mucosa-associated lymphoid tissue lymphoma

BACKGROUND AND AIMS

Colorectal mucosa-associated lymphoid tissue (MALT) lymphoma is a rare disease. The purpose of this study was to investigate the clinical and endoscopic features of colorectal MALT lymphoma.

METHODS

Patients diagnosed with colorectal MALT lymphoma at Asan Medical Center from 2002 to 2016 were eligible. Medical records were reviewed to investigate clinical features and treatment outcomes. Endoscopic pictures were assessed to characterize the endoscopic features of colorectal MALT lymphoma.

RESULTS

A total of 51 patients were enrolled. The median age was 60 years (interquartile range, 55-71), and 21 (41%) were men. Twenty-six patients (51%) were asymptomatic. Forty-four patients (86%) were in early disease stages, namely Lugano stages I, II, and II_E. Endoscopic appearances were classified as 4 distinct types: subepithelial tumor type (26 patients, 51%), polyposis type (10 patients, 20%), epithelial mass type (7 patients, 14%), and ileitis type (8 patients, 16%). The rectum (20 patients, 39%) was the most common location, followed by the ileocecal area (15 patients, 30%). An initial endoscopic impression of lymphoma was made in only 7 patients. Forceps biopsy sampling as the initial tissue acquisition method could histologically diagnose MALT lymphoma in 28 of 35 patients (80%). Polypectomy as the initial histologic diagnosis could diagnose MALT lymphoma in 16 of 16 patients. Progression-free and overall survival rates at 5 years were 92% and 94%, respectively.

CONCLUSIONS

Colorectal MALT lymphomas show various endoscopic appearances, complicating the endoscopic suspicion of colorectal MALT lymphoma. The prognosis of colorectal MALT lymphoma was excellent.

Dog Sperm Cryopreservation in Glucose-Fructose or Sucrose Supplemented Glycerol-Free Tris: Effect of Post-Thaw Incubation Time on Gene Expression Related to Apoptosis and Motility

　　OBJECTIVE: The study evaluated the effects of glucose-fructose or sucrose supplementation in glycerol-free Tris (GFT) solution on motility, viability, the level of reactive oxygen species (ROS), as well as the level of apoptosis (BAX and BCL2) and motility (SMCP)-related gene expression of dog spermatozoa.

MATERIALS AND METHODS

Spermatozoa (5×10⁷ sperm/ml) were cryopreserved in GFT containing 86 mM glucose and 86 mM fructose (GF-GFT) or 100 mM sucrose (S-GFT). Progressive motility, viability, ROS (H₂O₂) level and mRNA gene expression of spermatozoa were evaluated 0 h, 3 h or 6 h post-thaw at 24°C.

RESULTS

The motility of spermatozoa cryopreserved in GF-GFT was increased throughout the post-thaw incubation time. The motility of spermatozoa cryopreserved in S-GFT was increased at 3 h of post-thaw incubation. The sperm ROS level in the GF-GFT group was inconsistent during the post-thaw incubation time; however, the ROS level in the S-GFT group was gradually increased with progression of the post-thaw incubation period. The post-thaw incubation had no substantial effect on the mRNA expression of the BAX, BCL2, and SMCP genes of spermatozoa in both the GF-GFT and S-GFT groups.

CONCLUSION

The supplementation of glucose and fructose improves progressive sperm motility during 6 h of post-thaw incubation while maintaining similar sperm viability. The addition of GF to GFT for cryopreservation and post-thaw incubation would yield more functional spermatozoa for future assisted reproduction practices.

Assessment of factors associated with smoking cessation at diagnosis or during follow-up of Crohn's disease

BACKGROUND AND AIM

Smoking cessation is known to improve the course of Crohn's disease (CD). However, the factors associated with smoking cessation after CD diagnosis have not been well established.

METHODS

Clinical characteristics and change in smoking status were evaluated in 445 current smokers at the time of CD diagnosis. Patients were classified into three subgroups based on their final smoking status and time of smoking cessation: non-quitters, quitters at diagnosis, and quitters during follow-up.

RESULTS

The overall smoking cessation rate was 55.7% (248 of 445 patients). The diagnosis of CD was the main reason for quitting (41.5%, 103 of 248 patients). Smoking cessation at the time of CD diagnosis was associated with intestinal resection within 3 months from CD diagnosis (odds ratio [OR] 2.355, 95% confidence interval [CI] 1.348-4.116, P = 0.003), light smoking (OR 2.041, 95% CI 1.157-3.602, P = 0.014), and initiation of smoking before 18 years of age (OR 0.570, 95% CI 0.327-0.994, P = 0.047). Light smoking (OR 1.762, 95% CI 1.019-3.144, P = 0.043) and initiation of smoking before 18 years (OR 0.588, 95% CI 0.381-0.908, P = 0.017) were also associated with overall smoking cessation.

CONCLUSION

Quitters after CD diagnosis, including quitters at diagnosis and quitters during follow-up, had features distinct from those of non-quitters. Given the motivation at CD diagnosis, a detailed history of smoking habits should be taken and all current smokers should be encouraged to quit smoking at the time of CD diagnosis.

Clinical characteristics and long-term prognosis of elderly onset ulcerative colitis

BACKGROUND AND AIM

The aim of this study was to investigate the clinical characteristics and prognosis of patients with elderly onset ulcerative colitis (EOUC), a new growing subgroup of UC.

METHODS

This study retrospectively analyzed 3060 South Korean UC patients diagnosed between 1977 and 2014. The clinical characteristics and prognosis of EOUC, defined as UC in those aged ≥ 60 years at diagnosis, were compared with those of non-EOUC (NEOUC).

RESULTS

Among the 3060 patients, 226 were diagnosed with EOUC (7.4%, median age at diagnosis 65.9 years [interquartile range, 62.9-68.7 years], 58.4% male). The frequency of EOUC increased from 3.9% in the interval 1977-1999 to 9.7% in the interval 2008-2014 (P < 0.001). There were more ex-smokers in the EOUC than in the NEOUC group (44.2% vs 19.9%, P < 0.001). In the EOUC group, extensive colitis at diagnosis, and the maximum extent thereof, was less than in the NEOUC group (13.7% vs 22.6%, P = 0.002, and 34.5% vs 42.5%, P = 0.011, respectively). The 10-year cumulative colectomy rate was significantly higher in the EOUC than in the NEOUC group (12.6% vs 7.7%, P = 0.015). UC-related and all-cause mortality were higher in the EOUC than in the NEOUC group (3.5% vs 0.6%, P < 0.001, and 12.4% vs 1.8%, P < 0.001, respectively).

CONCLUSION

Elderly onset ulcerative colitis patients are likely to exhibit distinct features both at diagnosis and during follow-up. It is necessary to pay more attention to, and to conduct further studies on, this particular group of patients.

Rapamycin-insensitive companion of mTOR (RICTOR) amplification defines a subset of advanced gastric cancer and is sensitive to AZD2014-mediated mTORC1/2 inhibition

Background

Targeting oncogenic genomic aberrations is an established therapeutic strategy in multiple tumor types. Molecular classification has uncovered a number of novel targets, and rapamycin-insensitive companion of mTOR (RICTOR) amplification has been identified in lung cancer. Further investigation assessing the therapeutic potential of RICTOR amplification as a novel target across advanced cancers is needed.

Patients and methods

Tumor samples from 640 patients with metastatic solid tumors, primarily gastrointestinal and lung cancers were prospectively subjected to a next-generation sequencing (NGS) assay to identify molecular targets. Samples with NGS-detected RICTOR amplification were confirmed with FISH. A RICTOR-amplified patient-derived cell (PDC) line was generated and used to investigate the effectiveness of selective AKT, mTORC1, and mTORC1/2 inhibition.

Results

NGS identified 13 (2%) of 640 patients with RICTOR-amplified tumors (6 gastric, 3 NSCLC, 1 SCLC, 1 CRC, 1 sarcoma, 1 MUO). Of the 13 patients, seven patients had RICTOR protein overexpression by IHC. The prevalence of RICTOR amplification in gastric cancer by NGS was 3.8% (6/160). FISH testing confirmed amplification (RICTOR/control >2) in 5/13 (38%) of samples, including four gastric cancers and one lung cancer. Treatment of a RICTOR amplified PDC with a selective AKT (AZD5363), selective mTORC1 (everolimus), dual mTORC1/2 (AZD2014), and the multi-target kinase inhibitor pazopanib demonstrated preferential sensitivity to the mTORC1/2 inhibitor (AZD2014). Knockdown of RICTOR reversed PDC sensitivity to AZD2014, validating the importance of RICTOR amplification to the PDC line.

Conclusions

RICTOR amplification is a rare but therapeutically relevant genomic alteration across solid tumors. Our results support further pre-clinical and clinical investigation with AZD2014 in RICTOR amplified gastric cancer and highlights the importance of genomic profiling.

18F-NaF PET/CT for the evaluation of temporomandibular joint disorder

AIM

To investigate the usefulness of a quantitative parameter (maximum standardised uptake value [SUVmax]) of ¹⁸F-sodium fluoride (NaF) positron-emission tomography (PET)/computed tomography (CT) for the evaluation of temporomandibular joint (TMJ) disorder (TMD).

MATERIALS AND METHODS

Seventy-six TMD patients (male: female=14:62, age=40.3±17.1 years, bilateral: unilateral=40:36) with 152 TMJs were enrolled. The ¹⁸F-NaF PET/CT parameter (SUVmax) was compared with the presence of TMJ arthralgia (arthralgic=86, non-arthralgic=66) and clinical subtypes based on the Research Diagnostic Criteria for TMD Axis I (TMD osteoarthritis=49, non-TMD osteoarthritis=67, and asymptomatic TMJ=36). Splint therapy was applied to 48 patients for 6 months without considering ¹⁸F-NaF PET/CT findings. Post-splint therapy ¹⁸F-NaF PET/CT was performed in 32 patients and clinical responses to the therapy were classified into improvement (n=33), no change (n=10), or aggravation (n=7) for 50 TMJs excluding asymptomatic TMJs (n=14).

RESULTS

SUVmax was significantly greater in arthralgic TMJs than in non-arthralgic TMJs (6.62±3.56 versus 4.32±1.53, p<0.0001). SUVmax was also significantly greater in TMD osteoarthritis (6.75±3.85) than in non-TMD osteoarthritis (5.21±2.70) and asymptomatic TMJs (4.86±1.99; p=0.0386). After splint therapy, SUVmax was significantly increased in aggravated TMJs (from 7.80±3.72 to 11.00±5.74, p=0.0156), whereas no significant change in SUVmax was observed in improved (from 6.16±2.68 to 6.09±2.60, p=0.4915) and unchanged (from 6.46±4.19 to 6.77±4.32, p=0.3223) TMJs.

CONCLUSIONS

¹⁸F-NaF PET/CT is a useful imaging tool for TMD evaluation because SUVmax showed a fair diagnostic performance for arthralgic TMJ and TMD osteoarthritis, and a correlation with the therapeutic response.