A 10-year experience with anastomotic leaks in upper gastrointestinal surgery-Retrospective cohort study

BACKGROUND

Anastomotic leak (AL) in upper gastrointestinal (UGI) surgery continues to be a diagnostic challenge. We seek to identify clinical parameters that predict AL and examine the effectiveness of investigations in evaluating AL following UGI surgeries.

METHODS

592 patients underwent UGI surgeries with an anastomosis between January 2011 and January 2021. Data on patient characteristics, surgery, postoperative investigations and outcomes were prospectively collected and analysed.

RESULTS

The overall occurrence of AL was 6.4 %. Tachycardia >120 BPM (OR 6.959, 95 % CI 1.856-26.100, p = 0.004) and leukocyte count >19 × 109/L (OR 3.327, 95 % CI 1.009-10.967, p = 0.048) were independent predictors of AL. On multivariate analysis, patients whose anastomosis was deemed high risk and had pre-emptive investigation done postoperatively to exclude a leak were less likely to require intervention and were more likely to be managed conservatively (66.7 % vs 14.3 %, p = 0.025). Methylene blue test, oral contrast study and Computed Tomography scan with intravenous and oral contrast had 50.0 %, 20.0 % and 9.1 % false negative results, while esophagogastroduodenoscopy had none. There was no misdiagnosed AL when more than 1 investigation (n = 15, 39.5 %) were performed.

CONCLUSION

Our study demonstrates that the presence of a triad including desaturation, tachycardia and leucocytosis predicts for AL following UGI surgery and for confirmation of a leak, evaluation with 2 or more investigation is needed. A practice of evaluating high risk anastomosis prior to commencement of feeding decreased the need for surgical intervention and improves success of conservative treatment.

A systematic review and meta-analysis of mediastinoscopy-assisted transhiatal esophagectomy (MATHE)

BACKGROUND

Transhiatal esophagectomy (THE) avoids thoracotomy but sacrifices mediastinal lymphadenectomy. Mediastinoscopy-assisted transhiatal esophagectomy (MATHE) allows for visualisation and en-bloc dissection of mediastinal lymph nodes while retaining the benefits of THE. However, given its novel inception, there is a paucity of literature. This study aimed to conduct the first meta-analysis to explore the efficacy of MATHE and clarify its role in the future of esophagectomy.

METHODS

Four databases (PubMed, EMBASE, Scopus, and Cochrane Library) were searched from inception to May 1, 2023. Studies were included if they reported outcomes for patients with esophageal cancer who underwent MATHE. Meta-analyses of proportions and pooled means were performed for the outcomes of intraoperative blood loss, lymph node (LN) harvest, mean hospital length of stay (LOS), mean operative time, R0 resection, conversion rates, 30-day mortality rate, 5-year OS, and surgical complications (anastomotic leak, cardiovascular [CVS] and pulmonary complications, chyle leak and recurrent laryngeal nerve palsy [RLN]). Sensitivity analyses were performed for outcomes with substantial statistical heterogeneity.

RESULTS

The search yielded 223 articles; 28 studies and 1128 patients were included in our analysis. Meta-analyses of proportions yielded proportion rates: 30-day mortality (0 %, 95 %CI 0-0), 5-year OS (60.5 %, 95 %CI 47.6-72.7), R0 resection (100 %, 95 %CI 99.3-100), conversion rate (0.1 %, 95 %CI 0-1.2). Among surgical complications, RLN palsy (14.6 %, 95 %CI 9.5-20.4) were most observed, followed by pulmonary complications (11.3 %, 95 %CI 7-16.2), anastomotic leak (9.7 %, 95 %CI 6.8-12.8), CVS complications (2.3 %, 95 %CI 0.9-4.1) and chyle leak (0.02 %, 95 %CI 0-0.8). Meta-analysis of pooled means yielded means: LN harvest (18.6, 95 %CI 14.3-22.9), intraoperative blood loss (247.1 ml, 95 %CI 173.6-320.6), hospital LOS (18.1 days, 95 %CI 14.4-21.8), and operative time (301.5 min, 95 %CI 238.4-364.6). There was moderate-to-high statistical heterogeneity. Findings were robust to sensitivity analyses.

CONCLUSION

MATHE is associated with encouraging post-operative mortality and complication rates, while allowing for radical mediastinal lymphadenectomy with reasonable lymph node harvest.

Ameliorating effect of 2'-Fucosyllactose and 6'-Sialyllactose on lipopolysaccharide-induced intestinal inflammation

Human milk oligosaccharides (HMO) affect gut microbiota during neonatal development, particularly with respect to the immune system. Bovine milk-based infant formulas have low oligosaccharide contents. Thus, efforts to fortify infant formulas with HMO are being undertaken. Two major HMO, 2'-fucosyllactose (2'-FL) and 6'-sialyllactose (6'-SL), exert anti-inflammatory effects; however, the associations between anti-inflammatory effects induced by 2'-FL and 6'-SL co-treatment and gut microbiota composition and metabolite modulation remain unclear. Therefore, in this study, we evaluated the effects of a mixture of these HMO. To determine the optimal HMO ratio for anti-inflammatory effects and elucidate its mode of action, LPS-induced inflammatory HT-29 epithelial cells and intestinal inflamed suckling mice were treated with various mixtures of 2'-FL and 6'-SL. 2'-FL:6'-SL ratio of 5:1 was identified as the most effective pre-treatment HMO mixture in vitro; thus, this ratio was selected and used for low, middle, and high-dose treatments for subsequent in vivo studies. In vivo, high-dose HMO treatment restored LPS-induced inflammation symptoms, such as body weight loss, colon length reduction, histological structural damage, and intestinal gene expression related to inflammatory responses. High-dose HMO was the only treatment that modulated the major phyla Bacteroidetes and Firmicutes and the genera Ihubacter, Mageeibacillus, and Saccharofermentans. These changes in microbial composition were correlated with intestinal inflammation-related gene expression and short-chain fatty acid production. To our knowledge, our study is the first to report the effects of Ihubacter, Mageeibacillus, and Saccharofermentans on short chain fatty acid levels, which can subsequently affect inflammatory cytokine and tight junction protein levels. Conclusively, the HMO mixture exerted anti-inflammatory effects through changes in microbiota and metabolite production. These findings suggested that supplementation of infant formula with HMO may benefit formula-fed infants by forming unique microbiota contributing to neonatal development.

Management of newborns and healthcare workers exposed to isoniazid-resistant congenital tuberculosis in the neonatal intensive care unit

BACKGROUND

Management of newborns and healthcare workers (HCWs) exposed to congenital tuberculosis (TB) in the neonatal intensive care unit (NICU) has been reported rarely.

AIM

To outline a contact investigation process for individuals exposed to congenital TB in the NICU and investigate nosocomial transmission. Additionally, to assess the efficacy and safety of window prophylaxis in exposed newborns.

METHODS

A baby, born at a gestational age of 28 + 1 weeks, was diagnosed with isoniazid-resistant congenital TB on the 39th day of admission to the level IV NICU. Newborns and HCWs exposed cumulatively for ≥8 h underwent contact investigation and follow-up for a year.

FINDINGS

Eighty-two newborns underwent contact investigation. All newborns displayed normal chest X-rays, and 42 hospitalized newborns tested negative for acid-fast bacilli stain and Xpert® MTB/RIF assay in their endotracheal sputum or gastric juices. Eighty received window prophylaxis: six of 75 on rifampin experienced mild adverse events, and none of the five on levofloxacin. After 12 weeks, five (6.1%) had a positive tuberculin skin test, all of whom had already received the Bacillus Calmette-Guérin vaccine and tested negative on TB interferon-gamma releasing assay. Of 119 exposed HCWs, three (2.5%) were diagnosed with latent TB infection and completed a four-month rifampin therapy. There was no active TB disease among exposed newborns and HCWs during a one-year follow-up.

CONCLUSION

Timely diagnosis of congenital TB is crucial for minimizing transmission among exposed neonates and HCWs in the NICU setting. In cases of isoniazid-resistant index patients, even premature newborns may consider the use of rifampin or levofloxacin for window prophylaxis.

Uninsured immigrants in the United States significantly delayed the initiation of prenatal care after the changes to the Public Charge Rule

OBJECTIVE

We estimated the impact of the changes made to the Public Charge Rule on the initiation of prenatal care among uninsured immigrants in the United States.

STUDY DESIGN

We used a difference-in-differences approach to analyse the impact of the changes made to the Public Charge Rule (first difference) on initiation of prenatal care between uninsured and privately insured immigrants (second difference).

METHODS

We used the natality data by the National Center for Health Statistics as the main data source, which includes all singleton births in a hospital to an immigrant birthing person aged from 15 to 44. The study covers three phases: (1) the period prior to the leaked draft Executive Orders concerning changes made to the public charge policy-from January 2014 to December 2016; (2) the period after the draft Executive Orders were leaked until the proposal of the Public Charge Rule-from January 2017 to September 2018; and (3) post proposal of the Public Charge Rule -from October 2018 to December 2019.

RESULTS

After the proposal of the Public Charge Rule in 2018, the odds of initiating prenatal care in the first trimester decreased among uninsured immigrants by 12% (odds ratio [OR]: 0.880; 95% confidence interval [CI]: 0.832, 0.931) compared to privately insured immigrants. The odds of second trimester initiation of prenatal care was also negatively associated with the leak of the draft Executive Orders (OR: 0.942; 95% CI: 0.905, 0.981).

CONCLUSION

The results of this study suggest that uninsured immigrants in the United States significantly delayed prenatal care after the changes were made to the Public Charge Rule.

Single-incision transgastric resection for gastric gastrointestinal stromal tumors in anatomically challenging locations

Surgical resection is the mainstay treatment for resectable gastrointestinal stromal tumors (GISTs). However, resection in anatomically challenging locations, such as near the gastroesophageal junction, lesser curve and fundus, remain technically challenging. We herein report the outcomes of the largest series of patients who underwent single-incision transgastric resection of an intraluminal gastric GIST. Our reduced-port resection technique for intraluminal GISTs in these anatomically challenging locations involves a single incision in the left hypochondrium, deepened to access the gastric lumen, with the surgery completed in a transgastric manner. A total of 22 patients received surgery with this technique at the National University Hospital in Singapore from November 2012 to September 2020. The median operative time was 101 (range 50-253) min, with no conversions to open surgery, median lesion size 3.6 (range 1.8-8.2) cm and median postoperative length of stay 5 (range 1-13) days. There was no 30-day mortality and no recurrence during the follow-up period. Our laparoscopic approach for reduced-port transgastric excision of intraluminal GISTs allows for adequate surgical clearance, convenient extraction and secure gastrostomy closure with low morbidity.

A Phase II Trial Evaluating Rapid Mid-Treatment Nodal Shrinkage to Select for Adaptive Deescalation in p16+ Oropharyngeal Cancer Patients Undergoing Definitive Chemoradiation

PURPOSE/OBJECTIVE(S)

The purpose of this study is to determine if rapid mid-treatment nodal shrinkage (RMNS) can identify patients with p16+ oropharyngeal cancer (OPC) who can be safely deescalated with reduced dose chemoradiation therapy (CRT). The primary endpoint was 2-year progression free survival (PFS).

MATERIALS/METHODS

Inclusion criteria were as follows: T1-3, N1, M0 (AJCC 8th edition) p16+ OPC with <10 pack-year smoking history. All patients were initially planned for standard dose CRT (70 Gy) and weekly cisplatin. Patients were evaluated with a CT scan at week 4 for RMNS, defined as >40% nodal volumetric reduction from baseline. If RMNS was achieved, they proceeded to deescalated CRT (60 Gy). If not, they received standard CRT. Biomarker correlates were collected at baseline and week 4 of CRT including plasma TTMV (tumor tissue modified viral) HPV DNA and MRI diffusion weighted imaging (DWI). Univariate logistic regression analyses (UVA) were performed to evaluate predictors of RMNS. Odds ratios with 95% CI are reported, using a p<0.05 for statistical significance with a two-sided test. Wilcoxon rank sum tests were used to evaluate differences between the two groups using p < 0.05, 2-sided) for statistical significance. All statistical procedures were performed using R () with no adjustments for multiple testing.

RESULTS

Thirty-six patients were enrolled: median age: 60 years; 81% male; primary site: 36% base of tongue, 53% tonsil, 11% both; T-stage: 39% T1, 50% T2, 11% T3; N-stage: 100% N1; any smoking history: 58% yes, 42% no; 67% (n = 24) had RMNS and received deescalated CRT while the remaining proceeded to standard CRT. At a median follow-up of 32.4 months, 2-year PFS between the standard and deescalated groups were 91.7% vs 90.9%, respectively (p = 0.97). All patients with recurrence underwent successful salvage treatment with 2-year OS 100% for all patients. On UVA, rapid TTMV HPV DNA clearance (baseline to week 4) (OR 12.0 [1.65-250], p = 0.034), lower MRI diffusivity (ADC) at baseline (OR 0.79 [0.61-0.97], p = 0.042) and week 4 (OR 0.76 [0.60-0.91], p = 0.009), and higher MRI diffusional kurtosis at baseline (OR 1.09 [1.01-1.21], p = 0.051) and week 4 (OR 1.24 [1.09-1.52], p = 0.009) were significantly associated with RMNS. When comparing the deescalated and standard cohorts, the mean baseline and week 4 MRI ADC were significantly lower and week 4 MRI diffusional kurtosis was significantly higher in the deescalated group.

CONCLUSION

In this phase II study, rapid mid-treatment nodal shrinkage appeared to select favorable risk p16+ oropharynx cancer patients for treatment de-escalation. Rapid clearance of TTMV HPV DNA at week 4 as well as MRI DWI biomarkers of low ADC and high diffusional kurtosis values were correlated with RMNS. A larger study is planned to incorporate RMNS and biomarkers for further treatment de-escalation. Additional trial information is available at ClinicalTrials.gov (Identifier: NCT03215719).

Real-World Validation of a Computer-Aided Diagnosis System for Prediction of Polyp Histology in Colonoscopy: A Prospective Multicenter Study

INTRODUCTION

Computer-aided diagnosis (CADx) of polyp histology could support endoscopists in clinical decision-making. However, this has not been validated in a real-world setting.

METHODS

We performed a prospective, multicenter study comparing CADx and endoscopist predictions of polyp histology in real-time colonoscopy. Optical diagnosis based on visual inspection of polyps was made by experienced endoscopists. After this, the automated output from the CADx support tool was recorded. All imaged polyps were resected for histological assessment. Primary outcome was difference in diagnostic performance between CADx and endoscopist prediction of polyp histology. Subgroup analysis was performed for polyp size, bowel preparation, difficulty of location of the polyps, and endoscopist experience.

RESULTS

A total of 661 eligible polyps were resected in 320 patients aged ≥40 years between March 2021 and July 2022. CADx had an overall accuracy of 71.6% (95% confidence interval [CI] 68.0-75.0), compared with 75.2% (95% CI 71.7-78.4) for endoscopists ( P = 0.023). The sensitivity of CADx for neoplastic polyps was 61.8% (95% CI 56.9-66.5), compared with 70.3% (95% CI 65.7-74.7) for endoscopists ( P < 0.001). The interobserver agreement between CADx and endoscopist predictions of polyp histology was moderate (83.1% agreement, κ 0.661). When there was concordance between CADx and endoscopist predictions, the accuracy increased to 78.1%.

DISCUSSION

The overall diagnostic accuracy and sensitivity for neoplastic polyps was higher in experienced endoscopists compared with CADx predictions, with moderate interobserver agreement. Concordance in predictions increased this diagnostic accuracy. Further research is required to improve the performance of CADx and to establish its role in clinical practice.

Gastroscopy after positive screening for faecal immunochemical tests and colonoscopy: A systematic review

BACKGROUND

Colorectal cancer (CRC) screening using the faecal immunochemical test (FIT) kits based on the detection of occult blood in stool is widely advocated in numerous screening programs worldwide. However, CRC is not commonly diagnosed in positive cases. We undertook this review to determine if there is evidence to suggest the use of opportunistic oesophago-gastro-duodenoscopy (OGD) in patients without CRC.

METHODS

A systematic review encompassing three electronic databases was performed. All peer-reviewed studies of FIT-positive patients who underwent either OGD and colonoscopy concurrently or OGD post-colonoscopy were included. Only studies from 2008 to 2022 using FIT kits were included to ensure studies not previously included in an earlier review were being analysed. A forward citation search of the included articles was also conducted to ensure no relevant articles were missed.

RESULTS

A total of 2409 records were extracted. Only four studies fulfilled the selection criteria and were included. Although the rates of abnormal OGD results were relatively high in the four studies, only 3 of 605 (0.50%) patients had gastric cancer in the entire review sample. No other malignancies were identified in all four studies. Other notable pathologies such as gastric polyps and gastritis were also reported.

CONCLUSIONS

There is little overall evidence to recommend UGI screening for all FIT-positive patients following a colonoscopy. However, there may be a role for clinicians to consider opportunistic OGD in this group of patients. Future research should examine patient populations from other sociocultural contexts including cost-effective analysis when considering changes in health guidelines on UGI screening.

Malignant ascites as a marker of peritoneal carcinomatosis burden in patients with colorectal and gastroesophageal cancer

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Background: Malignant ascites occurs frequently in patients with gastric cancer (GC) and colorectal cancer (CRC) with peritoneal metastasis (PM). The presence of PM and malignant ascites have been independently reported to confer resistance to systemic therapy and poorer prognosis. However, the occurrence of malignant ascites as a function of increasing peritoneal carcinomatosis burden has been less studied and reported. Methods: We reviewed prospective cohorts of gastric cancer and colorectal cancer patients with PM. The first cohort was a prospective group of GCPM patients receiving bi-directional systemic and peritoneal-directed therapies (catheter-based intraperitoneal chemotherapy and/or pressurized intraperitoneal aerosol chemotherapy respectively) at a tertiary oncology center in Singapore. Clinico-pathological data, including Peritoneal Cancer Index (PCI) and the presence or absence of ascites based on diagnostic laparoscopy, was collected. To orthogonally validate the hypothesis of malignant ascites as a function of peritoneal carcinomatosis burden in gastrointestinal malignancies, we studied the relationship between ascites, PM and survival in an independent cohort of metastatic CRC patients eligible for first-line systemic treatment enrolled in two randomized clinical trials in different Italian cancer centers. Results: In the first cohort of 82 patients with GCPM, the median PCI was 19 (inter-quartile range (IQR) 8 – 26) in the group with ascites and 3 (IQR 1 – 12) in the group without ascites (p=0.005), suggesting ascites occurs with higher PM burden. The median overall survival (OS) was poorer in patients with ascites (13.4 vs 16.4 months, HR 1.6, 95% CI 0.9 – 2.8, p=0.082). The median OS in patients with PCI of <7 was 17.3 months (95% 12.0 – 22.7) and 13.8 months (95% CI 11.0 – 16.6) in those with PCI score >7. In the validation cohort of 900 CRC patients, presence of malignant ascites and PM resulted in poorer survival compared to patients with PM and no malignant ascites (HR for OS PM with ascites vs PM without ascites 2.01 (95% CI 1.37 - 2.96), p<0.001). Interestingly, those with PM and ascites had a poorer survival to those with stage IV disease without peritoneal involvement, while those with PM without ascites did not have a statistically significant difference (PM with malignant ascites vs. no peritoneal disease, HR for OS 2.14, 95% CI 1.57 – 3.01, p=0.007; PM without ascites vs no peritoneal disease, HR for OS 1.10, 95% CI 0.91 – 1.34). Conclusions: Our study of patients with colorectal or gastric cancer and peritoneal metastases suggest the presence of malignant ascites as a function of increased peritoneal carcinomatosis burden among patients with metastatic gastrointestinal malignancies, with correspondingly poorer survival outcomes.

Essential elements of weight loss apps for a multi-ethnic population with high BMI: a qualitative study with practical recommendations

Smartphone weight loss apps are constantly being developed but the essential elements needed by a multi-ethnic population with overweight and obesity remains unclear. Purpose: To explore the perceptions of an Asian multi-ethnic population with overweight and obesity on the essential elements of weight loss apps. Twenty two participants were purposively sampled from a specialist weight management clinic in Singapore from 13 April to 30 April 2021. Recorded interviews were conducted using face-to-face and videoconferencing modalities. Data saturation was reached at the 18th participant. Data analysis was performed using inductive content analysis with constant comparison between and within transcripts. Findings: Three themes and eight subthemes on the essential app components emerged-(a) comprehensive and flexible calorie counters; (b) holistic, gradual and individualized behavior change recommendations tailored for people with overweight and obesity, and (c) just-in-time reminders of future consequences. There was a need to incorporate flexible options for food logging; break down general recommendations into small steps towards sustainable changes; tailor app contents for people with overweight and obesity; and evoke one's considerations of future consequences. Future weight loss apps should be designed to meet the needs of those with overweight and obesity, the very population that needs assistance with weight loss. Future apps could consider leveraging the capacity of artificial intelligence to provide personalized weight management in terms of sustaining self-regulation behaviors, optimizing goal-setting and providing personalized and timely recommendations for weight loss.

Concomitant left atrial appendage closure with left ventricular assist device surgery can reduce ischemic cerebrovascular accidents

Background

It remains unknown if concomitant left atrial appendage closure (LAAC) at the time of left ventricular assist device (LVAD) surgery can reduce ischemic cerebrovascular accidents.

Purpose

The purpose of this study is to assess the impact of LAAC at LVAD surgery on the incidence of ischemic cerebrovascular accidents.

Methods

Between January 2012 and November 2021, 310 patients underwent LVAD surgery with HeartMate II or III. Out of 310 patients, 98 patients (31.6%) underwent concomitant LAAC. The cohort was divided into two groups: patients with LAAC (Group A, n=98) and without LAAC (Group B, n=212). To minimize device bias, LVAD surgery with HeartWare HVAD device was excluded. The ischemic cerebrovascular accident was defined as ischemic stroke, hemorrhagic stroke or transient ischemic attack. We reviewed early and long-term clinical outcomes. The incidence of ischemic cerebrovascular accidents was compared between two groups using the Kaplan-Meier method. We also investigated if LAAC was associated with ischemic cerebrovascular accidents by Cox proportional hazards analysis.

Results

There were no significant differences in baseline characteristics between two groups including age (Group A: 55.0±12.3 years old, Group B: 56.9±14.1 years old, p=0.26), preoperative CHADS2 score (Group A: 2.40±1.1, Group B: 2.58±1.1, p=0.19) and history of atrial fibrillation (Group A: 42.9%, Group B: 42.5%, p=0.95). In-hospital mortality was not significantly different between the two groups (Group A: 7.1%, Group B: 12.3%, p=0.16). In terms of postoperative complications, there were no significant differences between two groups in requiring extracorporeal membrane oxygenation, re-exploration for bleeding and newly required hemodialysis. Median follow up period was 474 days. Thirty-five patients (11.2%) developed ischemic cerebrovascular accidents (5 patients in Group A and 30 patients in Group B). The rate of freedom from ischemic cerebrovascular accidents in Group A (94.1% at 500 days and 94.1% at 1500 days) was significantly higher than that in Group B (88.2% at 500 days and 77.4% at 1500 days; log rank=0.024). In a Cox proportional hazards regression analysis including LAAC, age, history of atrial fibrillation, diabetes mellitus and Heartmate 3 device implantation, LAAC was associated with reducing the incidence of ischemic cerebrovascular accidents (hazard ratio 0.37, 95% CI 0.13–0.89, p=0.02).

Conclusion

Concomitant LAAC at the time of LVAD surgery can reduce ischemic cerebrovascular accidents without increasing perioperative mortality and complications.

Funding Acknowledgement

Type of funding sources: None.

Outcomes of a Phase II Study of Intraperitoneal Paclitaxel plus Systemic Capecitabine and Oxaliplatin (XELOX) for Gastric Cancer with Peritoneal Metastases

BACKGROUND

Adding intraperitoneal paclitaxel (IP-PTX) to paclitaxel/5-fluoropyrimidine has shown promising results in patients with gastric cancer peritoneal metastases (GCPM) but has not been studied with standard-of-care platinum/fluoropyrimidine combinations. Our goal to was evaluate IP-PTX with capecitabine/oxaliplatin (XELOX) in GCPM.

METHODS

Forty-four patients with GCPM received IP PTX (40 mg/m², Days 1, 8), oral capecitabine (1000 mg/m² twice daily, Days 1-14) and intravenous oxaliplatin (100 mg/m², Day 1) in 21-day cycles. Patients with synchronous GCPM underwent conversion surgery if they had good response after chemotherapy, conversion to negative cytology, no extraperitoneal metastasis, and no peritoneal disease during surgery. The primary endpoint was overall survival and secondary endpoints were progression-free survival and safety. Outcomes from the trial were compared against a matched cohort of 39 GCPM patients who received systemic chemotherapy (SC) comprising platinum/fluoropyrimidine.

RESULTS

The median OS for the IP and SC groups was 14.6 and 10.6 months (hazard ratio [HR] 0.44; 95% confidence interval [CI], 0.26-0.74; p = 0.002). The median PFS for the IP and SC group was 9.5 and 4.4 months respectively (HR 0.39; 95% CI 0.25-0.66; p < 0.001). Patients in the SC group were younger (IP vs. SC, 61 vs. 56 years, p = 0.021) and had better performance status (ECOG 0, IP vs. SC, 47.7% vs. 76.9%, p = 0.007) compared with the IP cohort. In IP group, conversion surgery was performed in 36.1% (13/36) of patients, with a median OS of 24.2 (95% CI 13.1-35.3) months and 1-year OS of 84.6%.

CONCLUSIONS

IP PTX with XELOX is a promising treatment option for GCPM patients. In patients with good response, conversion surgery was feasible with favourable outcomes.

The influence of anastomotic techniques on postoperative anastomotic complications: Results of the Oesophago-Gastric Anastomosis Audit

BACKGROUND

The optimal anastomotic techniques in esophagectomy to minimize rates of anastomotic leakage and conduit necrosis are not known. The aim of this study was to assess whether the anastomotic technique was associated with anastomotic failure after esophagectomy in the international Oesophago-Gastric Anastomosis Audit cohort.

METHODS

This prospective observational multicenter cohort study included patients undergoing esophagectomy for esophageal cancer over 9 months during 2018. The primary exposure was the anastomotic technique, classified as handsewn, linear stapled, or circular stapled. The primary outcome was anastomotic failure, namely a composite of anastomotic leakage and conduit necrosis, as defined by the Esophageal Complications Consensus Group. Multivariable logistic regression modeling was used to identify the association between anastomotic techniques and anastomotic failure, after adjustment for confounders.

RESULTS

Of the 2238 esophagectomies, the anastomosis was handsewn in 27.1%, linear stapled in 21.0%, and circular stapled in 51.9%. Anastomotic techniques differed significantly by the anastomosis sites (P < .001), with the majority of neck anastomoses being handsewn (69.9%), whereas most chest anastomoses were stapled (66.3% circular stapled and 19.3% linear stapled). Rates of anastomotic failure differed significantly among the anastomotic techniques (P < .001), from 19.3% in handsewn anastomoses, to 14.0% in linear stapled anastomoses, and 12.1% in circular stapled anastomoses. This effect remained significant after adjustment for confounding factors on multivariable analysis, with an odds ratio of 0.63 (95% CI, 0.46-0.86; P = .004) for circular stapled versus handsewn anastomosis. However, subgroup analysis by anastomosis site suggested that this effect was predominantly present in neck anastomoses, with anastomotic failure rates of 23.2% versus 14.6% versus 5.9% for handsewn versus linear stapled anastomoses versus circular stapled neck anastomoses, compared with 13.7% versus 13.8% versus 12.2% for chest anastomoses.

CONCLUSIONS

Handsewn anastomoses appear to be independently associated with higher rates of anastomotic failure compared with stapled anastomoses. However, this effect seems to be largely confined to neck anastomoses, with minimal differences between techniques observed for chest anastomoses. Further research into standardization of anastomotic approach and techniques may further improve outcomes.

POS0859 C-REACTIVE PROTEIN AND INTERLEUKIN-6: POTENTIAL BIOMARKERS OF DISEASE ACTIVITY AND TREATMENT RESPONSE IN SYSTEMIC SCLEROSIS-INTERSTITIAL LUNG DISEASE

Background

Clinically feasible and valid biomarkers of systemic sclerosis-interstitial lung disease (SSc-ILD) are needed. While promising candidate biomarkers are under investigation (e.g., KL-6, CCL-8), clinical assays for these proteins are not currently available. C-reactive protein (CRP) measurements are feasible, cost-effective, and have been shown to predict mortality in SSc.1 Measuring interleukin (IL)-6, a proinflammatory cytokine implicated in SSc-ILD pathogenesis, is also feasible in most clinical settings.

Objectives

(1) To investigate whether CRP and IL-6 levels change in response to treatment with immunosuppression in SSc-ILD; (2) To explore whether the change in CRP and IL-6 predict the future course of forced vital capacity (FVC).

Methods

CRP and IL-6 levels were measured in serum at baseline and after 12 months in participants of Scleroderma Lung Study (SLS) II (patients with active SSc-ILD receiving 24 months of mycophenolate or 12 months cyclophosphamide followed by 12 months of placebo2). Measured values were log-transformed to remove skewness. The FVC%-predicted was measured every 3 months over the course of 24 months. Spearman’s correlations evaluated the relationship between baseline CRP or IL-6 measurements and other patient parameters. Paired t-tests were used to compare the change in individual CRP and IL-6 measurements from baseline to 12 months. Linear mixed effects models were used to examine the relationship between the change in CRP and IL-6 (baseline to 12 months) and the subsequent course of the FVC (12 to 24 months). All analysis were performed for the entire cohort and separately by treatment arm.

Results

Of the 142 participants of SLS II, 101 had CRP and IL-6 measurements at baseline and 12 months. Baseline CRP and IL-6 levels correlated significantly with higher modified Rodnan skin score (CRP: r=0.3, P=0.005; IL-6: r=0.2, P=0.01) and shorter disease duration (CRP: r=-0.3, P=0.005; IL-6: r=-0.2, P=0.01) and were higher in patients with diffuse SSc (CRP: P=0.007; IL-6: P=0.01). Relationships to baseline FVC and DLCO were not observed. CRP decreased significantly from baseline to 12 months in the whole group (P=0.01), but the decrease was slightly greater in patients randomized to mycophenolate versus cyclophosphamide (-0.47 vs. -0.33 ug/mL). IL-6 also decreased from baseline to 12 months in the whole group with a trend towards significance (P=0.10) (Figure 1). The mean decrease in IL-6 was again slightly greater in patients randomized to mycophenolate versus cyclophosphamide (-0.31 vs. -0.10 pg/mL). After controlling for baseline FVC and treatment arm in the mixed effects model, there was a relationship between the decrease in CRP from baseline to 12 months and an improved course of FVC 12 to 24 months (Estimate -0.64), but this did not reach significance (P=0.14). However, after controlling for baseline FVC and treatment arm, a greater decrease in IL-6 from baseline to 12 months was significantly associated with a greater improvement in FVC from 12 to 24 months (Estimate -1.28; P=0.01).

Figure 1.

Change in CRP (A) and IL-6 (B) from baseline to 12 months by treatment arm in SLS II. CYC=cyclophosphamide (Blue), MMF=mycophenolate (red)

Conclusion

Patients with active SSc-ILD receiving one year of immunosuppressive therapy in the SLS II study experienced reductions in their CRP and IL-6 levels over this interval. The magnitude of the decrease in CRP and IL-6 over the first year also correlated with the course of FVC over the ensuing 12 months. These findings suggest a dynamic relationship between CRP and IL-6 measurements and the course of SSc-ILD in patients on immunosuppressive therapy. Further investigation of these findings is warranted.

References

[1]Liu et al. Arthritis Care Res 2013.

[2]Tashkin et al. Lancet Resp Med 2016.

Disclosure of Interests

Elizabeth Volkmann Speakers bureau: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Grant/research support from: Forbius, Kadmon, Horizon, Boehringer Ingelheim, Donald Tashkin: None declared, Holly Wilhalme: None declared, Marka Lyons: None declared, Grace Kim: None declared, Jonathan Goldin: None declared, Michael Roth Grant/research support from: Genentech, Shervin Assassi Consultant of: Boehringer Ingelheim

POS0852 SYMPTOMS OF GASTROESOPHAGEAL REFLUX ARE A BETTER PREDICTOR OF SYSTEMIC SCLEROSIS-RELATED INTERSTITIAL LUNG DISEASE PROGRESSION THAN QUANTITATIVE RADIOGRAPHIC ASSESSMENT OF ESOPHAGEAL PARAMETERS

Background

Esophageal dysfunction affects the majority of patients with systemic sclerosis (SSc). Gastroesophageal reflux (GERD)-associated microaspiration may serve as an inciting and/or exacerbating factor in the pathogenesis of interstitial lung disease (ILD) in SSc. Few studies have investigated the relationship between objective measures of esophageal involvement in SSc and the progression of SSc-ILD.

Objectives

(1) To investigate whether patient-reported symptoms of GERD predict SSc-ILD severity and progression; (2) To explore whether quantitative radiographic measurements of esophageal parameters predict SSc-ILD severity and progression.

Methods

Participants of Scleroderma Lung Study (SLS) II (24 months of mycophenolate versus 12 months cyclophosphamide followed by 12 months of placebo in patients with active SSc-ILD) were included.1 The UCLA SCTC GIT 2.0 was used to assess the severity of reflux at baseline. Quantitative image analysis was used to calculate the diameter and area of the esophagus in the area of maximum dilation. Univariate and multivariable linear regression analyses were used to evaluate the relationship between baseline reflux scores/esophageal parameters and the severity and progression of SSc-ILD based on the quantitative radiographic extent of ILD (QILD) and fibrosis (QLF) in the lobe of maximum involvement (LM). All multivariable models controlled for treatment arm and baseline ILD severity, as well as proton pump inhibitor (PPI) use.

Results

Among the 141 of 142 SLS II participants with patient-reported reflux scores at baseline, the mean score was 0.57, indicating moderate reflux. The mean maximal esophageal diameter and area at baseline were 22 mm and 242 mm2, respectively. There were no significant correlations between reflux scores, esophageal diameter, esophageal area and QILD-LM and QLF-LM at baseline. However, in the 96 participants with HRCT scans available at 24 months, increased reflux scores were significantly associated with worsening of QLF-LM and QILD-LM (Figure 1). Even after controlling for disease severity at baseline, treatment arm and PPI use, reflux scores remained significantly associated with change in QLF-LM (P-value 0.05) and QILD-LM (P-value 0.003). Neither the maximum esophageal area, nor the maximum esophageal diameter was associated with the change in QILD-LM or QLF-LM in univariate or multivariate analyses.

Figure 1.

Increased reflux scores at baseline are associated with increased progression (worsening) of QILD (A) and QLF (B) in the lobe of maximum involvement in patients with SSc-ILD.

Conclusion

Increased self-reported reflux was independently associated with worsening radiographic fibrosis and ILD in patients receiving treatment for SSc-ILD. The maximum esophageal diameter and esophageal area did not correlate with reflux scores and did not predict severity or progression of SSc-ILD. These findings illustrate the importance of eliciting a careful patient history of reflux symptoms in patients with ILD and further highlight the need for improved objective measures of esophageal dysfunction in SSc.

References

[1]Tashkin et al. Lancet Resp Med 2016.

Disclosure of Interests

Elizabeth Volkmann Speakers bureau: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Grant/research support from: Forbius, Horizon, Kadmon, Boehringer Ingelheim, Donald Tashkin: None declared, Mei Leng: None declared, Grace Kim: None declared, Jonathan Goldin: None declared, Michael Roth Grant/research support from: Genentech

POS0068 CHANGES IN QUANTITATIVE INTERSTITIAL LUNG DISEASE SCORES ON HIGH-RESOLUTION CT IN IDIOPATHIC INFLAMMATORY MYOSITIS

Background

The idiopathic inflammatory myopathies (IIM) are autoimmune connective tissue diseases affecting skeletal muscle, skin and other organ systems. IIM-related interstitial lung disease (IIM-ILD) is the most common extra-muscular manifestation, being the leading cause of morbidity and mortality. Several studies have suggested that ILD pattern based on chest high-resolution computed tomography (HRCT) can be related to disease course and treatment response, but the results vary considerably. Moreover, the clinical impact of the quantitative ILD (QILD) score, a validated computer-aided scoring system in assessing ILD severity from HRCT, and its longitudinal changes have not yet been evaluated in IIM-ILD.

Objectives

This study aims to investigate ILD patterns and QILD scores in patients with IIM-ILD, to identify their clinical impact, and to delineate longitudinal changes of QILD measurement.

Methods

A total of 80 patients with IIM (polymyositis 22, and dermatomyositis 58) who underwent at least 2 times of serial HRCT scans were included. Visual ILD patterns were assessed by multiple thoracic radiologists. Quantitative analysis of HRCT was presented as total extent of QILD scores (%) in whole lung and most severe zone. Individual time-estimated ΔQILD score between first 2 visits was derived using a linear approximation of yearly change, where the duration of median (IQR) was 1.0 (0.4-1.6) years in the first 2 HRCT scans.

Results

The median (IQR) age of the patients was 52.0 (43.5-58.5) years and 60 (75.0%) were women. Baseline median score of whole lung-QILD and most severe zone-QILD were 28.1% (19.1-43.8) and 68.0% (45.5-81.8), respectively, and QILD score showed significant correlations with pulmonary function tests (r=-0.349, p=0.002 for % predicted forced vital capacity; and r=-0.381, p=0.001 for % predicted diffusing capacity for carbon monoxide). The individual time-estimated yearly ΔQILD score between first 2 visits presented that approximately half of the patients showed improvement or stability in QILD scores; however, when patients were sorted by visual assessment in ILD subtype on HRCT, approximately two-thirds of the patients with usual interstitial pneumonia (UIP) pattern were aggravated in QILD scores and less than half of subjects with nonspecific interstitial pneumonia and organizing pneumonia were aggravated (Figure 1, 80% for UIP vs. 44.4% for non-UIP, p=0.013). There was no immunosuppressive drugs related to meaningful improvement in QILD scores during first 2 visits. Notably, we observed significant aggravation of QILD scores in tacrolimus users (n=7, median time-estimated whole lung-yarly ΔQILD 20.3 (2.7-38.4)) compared with tacrolimus non-users (n=73, median time estimated whole lung-yearly ΔQILD -1.2 (-8.3-6.5)). Among 80 patients, 6 (7.5%) were died due to various lung complications. Higher baseline QILD scores were noted in deaths (median whole lung-QILD 45.4 (32.9-56.5)) than in survivors (median whole lung-QILD 26.9 (19.0-42.4)), albeit not significant (p=0.084). Poor survival rate was observed in patients with high grade of ground glass opacity by visual assessment in right upper lobe (log-rank test, p=0.042). Among subgroup of patients with 3 serial HRCT scans (n=41), dynamic changes of four distinct patterns (improving, worsening, convex, and concave) were observed.

Figure 1.

Cleveland dot plot of individual time-estimated yearly ΔQILD during fist 2 visits.

Conclusion

The changes in QILD score in IIM-ILD are dynamic and present different by visual assessment. QILD score has the potential for evaluation of the severity changes, prognosis and medication response in patients with IIM-ILD.

References

[1]Tashkin DP, et al. Ann Rheum Dis 2016;75(2):374-81.

7 truncated values in the graph A. NSIP: nonspecific interstitial pneumonia; OP: organizing pneumonia; UIP: usual interstitial pneumonia.

Disclosure of Interests

None declared

Textbook outcome following oesophagectomy for cancer: international cohort study

Background

Textbook outcome has been proposed as a tool for the assessment of oncological surgical care. However, an international assessment in patients undergoing oesophagectomy for oesophageal cancer has not been reported. This study aimed to assess textbook outcome in an international setting.

Methods

Patients undergoing curative resection for oesophageal cancer were identified from the international Oesophagogastric Anastomosis Audit (OGAA) from April 2018 to December 2018. Textbook outcome was defined as the percentage of patients who underwent a complete tumour resection with at least 15 lymph nodes in the resected specimen and an uneventful postoperative course, without hospital readmission. A multivariable binary logistic regression model was used to identify factors independently associated with textbook outcome, and results are presented as odds ratio (OR) and 95 per cent confidence intervals (95 per cent c.i.).

Results

Of 2159 patients with oesophageal cancer, 39.7 per cent achieved a textbook outcome. The outcome parameter ‘no major postoperative complication’ had the greatest negative impact on a textbook outcome for patients with oesophageal cancer, compared to other textbook outcome parameters. Multivariable analysis identified male gender and increasing Charlson comorbidity index with a significantly lower likelihood of textbook outcome. Presence of 24-hour on-call rota for oesophageal surgeons (OR 2.05, 95 per cent c.i. 1.30 to 3.22; P = 0.002) and radiology (OR 1.54, 95 per cent c.i. 1.05 to 2.24; P = 0.027), total minimally invasive oesophagectomies (OR 1.63, 95 per cent c.i. 1.27 to 2.08; P &lt; 0.001), and chest anastomosis above azygous (OR 2.17, 95 per cent c.i. 1.58 to 2.98; P &lt; 0.001) were independently associated with a significantly increased likelihood of textbook outcome.

Conclusion

Textbook outcome is achieved in less than 40 per cent of patients having oesophagectomy for cancer. Improvements in centralization, hospital resources, access to minimal access surgery, and adoption of newer techniques for improving lymph node yield could improve textbook outcome.

Textbook outcome following oesophagectomy for cancer: international cohort study

BACKGROUND

Textbook outcome has been proposed as a tool for the assessment of oncological surgical care. However, an international assessment in patients undergoing oesophagectomy for oesophageal cancer has not been reported. This study aimed to assess textbook outcome in an international setting.

METHODS

Patients undergoing curative resection for oesophageal cancer were identified from the international Oesophagogastric Anastomosis Audit (OGAA) from April 2018 to December 2018. Textbook outcome was defined as the percentage of patients who underwent a complete tumour resection with at least 15 lymph nodes in the resected specimen and an uneventful postoperative course, without hospital readmission. A multivariable binary logistic regression model was used to identify factors independently associated with textbook outcome, and results are presented as odds ratio (OR) and 95 per cent confidence intervals (95 per cent c.i.).

RESULTS

Of 2159 patients with oesophageal cancer, 39.7 per cent achieved a textbook outcome. The outcome parameter 'no major postoperative complication' had the greatest negative impact on a textbook outcome for patients with oesophageal cancer, compared to other textbook outcome parameters. Multivariable analysis identified male gender and increasing Charlson comorbidity index with a significantly lower likelihood of textbook outcome. Presence of 24-hour on-call rota for oesophageal surgeons (OR 2.05, 95 per cent c.i. 1.30 to 3.22; P = 0.002) and radiology (OR 1.54, 95 per cent c.i. 1.05 to 2.24; P = 0.027), total minimally invasive oesophagectomies (OR 1.63, 95 per cent c.i. 1.27 to 2.08; P < 0.001), and chest anastomosis above azygous (OR 2.17, 95 per cent c.i. 1.58 to 2.98; P < 0.001) were independently associated with a significantly increased likelihood of textbook outcome.

CONCLUSION

Textbook outcome is achieved in less than 40 per cent of patients having oesophagectomy for cancer. Improvements in centralization, hospital resources, access to minimal access surgery, and adoption of newer techniques for improving lymph node yield could improve textbook outcome.

Attenuation of intrinsic aging of the skin via elimination of senescent dermal fibroblasts with senolytic drugs

BACKGROUND

Skin aging is caused by numerous factors that result in structural and functional changes in cutaneous components. Research has shown that senescent cells are known to accumulate in skin aging, however, the role of senescent cells in skin aging has not been defined.

OBJECTIVES

To elucidate the role of senescent cell in skin aging, we evaluated the effect of known senolytic drugs on senescent dermal fibroblasts.

METHODS

Primary human dermal fibroblasts (HDFs) were induced to senescence by long-term passaging, UV irradiation, and H2O2 treatment. Cell viability was measured after treatment of ABT-263 and ABT-737 on HDFs. Young and aged hairless mice were intradermally injected with drugs or vehicle on the dorsal skin for 10 days. Skin specimens were obtained and reverse-transcription quantitative PCR, western blotting, and histological analysis were performed.

RESULTS

We found that ABT-263 and ABT-737 induced selective clearance of senescent dermal fibroblasts, regardless of the method of senescence induction. Aged mouse skin treated with ABT-263 or ABT-737 showed increased collagen density, epidermal thickness, and proliferation of keratinocytes, as well as decreased senescence-associated secretory phenotypes, such as MMP-1 and IL-6.

CONCLUSIONS

Taken together, our results indicate that selective clearance of senescent skin cells can attenuate and improve skin aging phenotypes and that senolytic drugs may be of potential use as new therapeutic agents for treating aging of the skin.

Single-Cell Atlas of Lineage States, Tumor Microenvironment, and Subtype-Specific Expression Programs in Gastric Cancer

Gastric cancer heterogeneity represents a barrier to disease management. We generated a comprehensive single-cell atlas of gastric cancer (>200,000 cells) comprising 48 samples from 31 patients across clinical stages and histologic subtypes. We identified 34 distinct cell-lineage states including novel rare cell populations. Many lineage states exhibited distinct cancer-associated expression profiles, individually contributing to a combined tumor-wide molecular collage. We observed increased plasma cell proportions in diffuse-type tumors associated with epithelial-resident KLF2 and stage-wise accrual of cancer-associated fibroblast subpopulations marked by high INHBA and FAP coexpression. Single-cell comparisons between patient-derived organoids (PDO) and primary tumors highlighted inter- and intralineage similarities and differences, demarcating molecular boundaries of PDOs as experimental models. We complemented these findings by spatial transcriptomics, orthogonal validation in independent bulk RNA-sequencing cohorts, and functional demonstration using in vitro and in vivo models. Our results provide a high-resolution molecular resource of intra- and interpatient lineage states across distinct gastric cancer subtypes.

SIGNIFICANCE

We profiled gastric malignancies at single-cell resolution and identified increased plasma cell proportions as a novel feature of diffuse-type tumors. We also uncovered distinct cancer-associated fibroblast subtypes with INHBA-FAP-high cell populations as predictors of poor clinical prognosis. Our findings highlight potential origins of deregulated cell states in the gastric tumor ecosystem. This article is highlighted in the In This Issue feature, p. 587.

Right ventricle function before and after different types of cardiac surgery

Funding Acknowledgements

Type of funding sources: None.

Background

Right ventricular (RV) dysfunction is an established independent predictor for adverse prognosis in a heterogeneous group of cardiac surgery patients (pts). However, there is lack of information about normal and abnormal dynamics of echocardiographic parameters for different types of cardiac surgery.

The aim of the study was to define changes in RV parameters after cardiac surgery.

Methods

sixty-five pts (39 men, 62 ± 9 years old) were selected into prospective study (NCT03953755). There were the groups of pts with left-sided valves surgery with/ without tricuspid valve (TV) repair, and pts with left-sided coronary artery bypass surgery without lesions of right coronary artery were included control group. A transthoracic echocardiography assessment before and an average of 101 days (88-115) following the operation was performed. Tricuspid annular plane systolic excursion (TAPSE), fractional area change (FAC), strain of the RV free wall (SRV), and right atrial volume were assessed in groups of patients with and without tricuspid valve repair as in CABG-group. Follow-up during 12 months was available in all pts.

Results

Valve repair for secondary tricuspid regurgitation was performed in nineteen patients undergoing left-sided valve surgery. Thirty-six patients had repair and/or replacement of left-sided valves without a tricuspid valve operation. There was a strong correlation between TAPSE, FAC, and RV strain before the operation (R = 0.61-0.67, p &lt; 0.000001). However, there was no correlation between TAPSE and FAC; TAPSE, and RV strain after the operation. TAPSE and RV strain significantly decreased after the operations and were below the normal range in both the groups with valve surgery, whereas, the CABG group showed only significantly TAPSE decreasing, RV strain was unchanged. TAPSE was 20 ± 5mm vs. 13 ± 2 mm, p &lt; 0.0003 for the group which underwent tricuspid valve repair; 22 ± 4mm vs. 14 ± 4 mm, p &lt; 0.0000001 for the group with tricuspid valves which were not operated on; 25 ± 6mm vs. 16 ± 3 mm, p &lt; 0.009 for CABG group. There was no difference in TAPSE and SRV ranges among patients with and without tricuspid valve repair. Dynamics in SRV didn’t correlate with patients’ clinical status or with normalized right chambers volumes. An increase in FAC correlated with a decrease in right chamber sizes after operations (R=-0.46, p &lt; 0.03). More prominent decreasing in TAPSE was connected in adverse events during follow-up (dTAPSE 6.7 ± 3.5 mm vs. 12.7 ± 5.1 mm, p &lt; 0.02)

Conclusion

TAPSE significantly decreases in all patients after CABG or valve cardiac operations with/without tricuspid valve repair, range of TAPSE were below normal standard in all patients. However more severe decreasing in TAPSE is connected with further adverse outcomes.

Bactericidal and antibiofilm properties of Rumex japonicus Houtt. on multidrug-resistant Staphylococcus aureus isolated from milk

Multidrug-resistant (MDR) Staphylococcus aureus and its biofilm formation have been challenging to control in milk and dairy industries. Biofilms formed by Staph. aureus may result in the failure of antibacterial agents and disinfectants to penetrate the biofilm in an attempt to control contamination. Novel natural antibacterial agents are required to combat MDR bacteria and biofilms. In this study, we evaluated the bactericidal, antibiofilm, and antimotility effects of Rumex japonicus Houtt. (RJH) extract on MDR Staph. aureus isolated from milk. The RJH extract exhibited good antibacterial activity against MDR strains with minimum inhibitory concentrations (MIC) ranging from 0.78 to 6.25 mg/mL and minimum bactericidal concentrations ranging from 3.125 to 12.5 mg/mL. The extract showed strong inhibition of biofilm formation (81.9%) at sub-MIC value and eradication of biofilm at higher concentrations. The motility of Staph. aureus was effectively blocked by the extract. Major compounds emodin, chrysophanol, and physcion were identified in RJH extract using HPLC-linear trap quadrupole (LTQ)/Orbitrap-mass spectrometry. The extract was nontoxic to human epithelial cell lines such as Caco-2 and HT-29 cell lines at concentrations ranging from 0.1 to 0.5 mg/mL, and from 0.1 to 0.75 mg/mL, respectively. These findings suggest that RJH extract could be an alternative to synthetic preservatives in milk and dairy products.

Induction of Gastric Cancer by Successive Oncogenic Activation in the Corpus

BACKGROUND & AIMS

Metaplasia and dysplasia in the corpus are reportedly derived from de-differentiation of chief cells. However, the cellular origin of metaplasia and cancer remained uncertain. Therefore, we investigated whether pepsinogen C (PGC) transcript-expressing cells represent the cellular origin of metaplasia and cancer using a novel Pgc-specific CreERT2 recombinase mouse model.

METHODS

We generated a Pgc-mCherry-IRES-CreERT2 (Pgc-CreERT2) knock-in mouse model. Pgc-CreERT2/+ and Rosa-EYFP mice were crossed to generate Pgc-CreERT2/Rosa-EYFP (Pgc-CreERT2/YFP) mice. Gastric tissues were collected, followed by lineage-tracing experiments and histologic and immunofluorescence staining. We further established Pgc-CreERT2;KrasG12D/+ mice and investigated whether PGC transcript-expressing cells are responsible for the precancerous state in gastric glands. To investigate cancer development from PGC transcript-expressing cells with activated Kras, inactivated Apc, and Trp53 signaling pathways, we crossed Pgc-CreERT2/+ mice with conditional KrasG12D, Apcflox, Trp53flox mice.

RESULTS

Expectedly, mCherry mainly labeled chief cells in the Pgc-CreERT2 mice. However, mCherry was also detected throughout the neck cell and isthmal stem/progenitor regions, albeit at lower levels. In the Pgc-CreERT2;KrasG12D/+ mice, PGC transcript-expressing cells with KrasG12D/+ mutation presented pseudopyloric metaplasia. The early induction of proliferation at the isthmus may reflect the ability of isthmal progenitors to react rapidly to Pgc-driven KrasG12D/+ oncogenic mutation. Furthermore, Pgc-CreERT2;KrasG12D/+;Apcflox/flox mice presented intramucosal dysplasia/carcinoma and Pgc-CreERT2;KrasG12D/+;Apcflox/flox;Trp53flox/flox mice presented invasive and metastatic gastric carcinoma.

CONCLUSIONS

The Pgc-CreERT2 knock-in mouse is an invaluable tool to study the effects of successive oncogenic activation in the mouse corpus. Time-course observations can be made regarding the responses of isthmal and chief cells to oncogenic insults. We can observe stomach-specific tumorigenesis from the beginning to metastatic development.