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1.  In Vivo and In Situ Evaluation of a Wireless Magnetoelastic Sensor Array for Plastic Biliary Stent Monitoring 
Biomedical microdevices  2013;15(3):509-517.
This paper presents the in vivo and in situ evaluation of a system that wirelessly monitors the accumulation of biliary sludge in a plastic biliary stent. The sensing element, located within the stent, is a passive array of magnetoelastic resonators that is queried by a wireless electromagnetic signal. The in vivo and in situ testing uses commercially-available plastic biliary stents, each enhanced with an array of ribbon sensors (formed from Metglas™ 2826MB). The sensor array is approximately 70 mm long and contains individual resonators that are 1 mm in width and have lengths of 10 mm, 14 mm, and 20 mm. The array is anchored into the 2.8 mm inner-diameter stent using a thermal staking technique. For the in situ testing, an instrumented stent is placed in various locations within the abdominal cavity of a female domestic swine carcass to evaluate the wireless range of the system; these results show that a wireless signal can be obtained from a range of at least 7.5 cm from a sensor array covered in bile. The in vivo testing includes the endoscopic implantation of an instrumented stent into the bile duct of a swine. After implantation, the swine was housed for a period of 4 weeks, during which the animal showed no ill effects and followed the expected growth curve from 29 kg to 42 kg. At the conclusion of the in vivo test, the animal was euthanized, and the instrumented stent explanted and examined. The results presented in this paper indicate that the monitoring system does not adversely affect the health of the animal and can feasibly provide sufficient wireless range after implantation.
doi:10.1007/s10544-013-9750-3
PMCID: PMC3738268  PMID: 23460136
Implant; Resonant Sensors; Biliary Sludge; Mass Sensors; Viscosity Sensors
2.  A survey of expert follow-up practices after successful endoscopic eradication therapy for Barrett's esophagus with high-grade dysplasia and intramucosal adenocarcinoma 
Gastrointestinal endoscopy  2013;78(5):696-701.
Background
Despite the increasing number of patients undergoing endoscopic therapy for Barrett's esophagus (BE) with high-grade dysplasia (HGD) or intramucosal cancer (IMC), there are few data to guide clinical decision making and research initiatives in the area of posttreatment follow-up.
Objectives
We aimed to define expert practice patterns regarding follow-up after endoscopic treatment of BE with HGD and IMC.
Design
Electronic survey.
Subjects
Forty-eight endoscopists in the United States with expertise in BE endotherapy based on high-impact publications and national reputation.
Intervention
A 21-item Web-based survey inquiring about post-BE endotherapy follow-up practices.
Results
Of 48 expert endoscopists, 42 completed the survey. After successful treatment of BE with HGD or IMC, all experts perform surveillance upper endoscopy, most commonly at 3-month intervals in the first posttreatment year, every 6 months during the second year, and annually thereafter. None of the experts perform surveillance EUS after treatment of HGD, and only 19% perform EUS after treatment of IMC. After cancer eradication, only 36% of experts refer patients for CT, and 24% refer patients for positron emission tomography. Thirty-eight percent of experts refer patients for a surgical opinion when IMC extends into the muscularis mucosa; 100% refer when IMC extends into submucosa.
Limitations
Not a consensus document; only U.S. experts included.
Conclusions
This study reports the follow-up practices of expert endoscopists after successful endotherapy for BE with HGD and IMC. Additional research is necessary to establish optimal surveillance intervals, the role of follow-up EUS, CT, and positron emission tomography, as well as the surgical implications of low-risk IMC extending into the muscularis mucosa.
doi:10.1016/j.gie.2013.04.196
PMCID: PMC3961573  PMID: 23711553
3.  Targeted imaging of esophageal neoplasia with a fluorescently labeled peptide: First in-human results 
Science translational medicine  2013;5(184):10.1126/scitranslmed.3004733.
Esophageal adenocarcinoma is rising rapidly in incidence, and usually develops from Barrett’s esophagus, a precursor condition commonly found in patients with chronic acid reflux. Pre-malignant lesions are challenging to detect on conventional screening endoscopy because of their flat appearance. Molecular changes can be used to improve detection of early neoplasia. We have developed a peptide that binds specifically to high-grade dysplasia and adenocarcinoma. We first applied the peptide ex vivo to esophageal specimens from 17 patients to validate specific binding. Next, we performed confocal endomicroscopy in vivo in 25 human subjects after topical peptide administration and found 3.8-fold greater fluorescence intensity for esophageal neoplasia compared with Barrett’s esophagus and squamous epithelium with 75% sensitivity and 97% specificity. No toxicity was attributed to the peptide in either animal or patient studies. Therefore, our first-in-humans results show that this targeted imaging agent is safe, and may be useful for guiding tissue biopsy and for early detection of esophageal neoplasia and potentially other cancers of epithelial origin, such as bladder, colon, lung, pancreas, and stomach.
doi:10.1126/scitranslmed.3004733
PMCID: PMC3859345  PMID: 23658246
4.  A comparison of surgical and endoscopic sample collection for pancreatic cyst fluid biomarker identification 
Journal of Proteome Research  2012;11(5):2904-2911.
Significant efforts are underway to develop new biomarkers from pancreatic cyst fluid. Previous research has made use of cyst fluid collected from surgically-removed cysts, but the clinical implementation of biomarkers would use cyst fluid collected by endoscopic ultrasound-guided, fine-needle aspiration (EUS-FNA). The purpose of this study was to investigate the clinical applicability of cyst fluid research obtained using surgical specimens. Matched pairs of operating-room collected (OR) and EUS-FNA samples from 12 patients were evaluated for the levels of three previously described biomarkers, CA 19-9, CEA, and glycan levels detected by wheat germ agglutinin on MUC5AC (MUC5AC-WGA). CA 19-9 and MUC5AC-WGA correlated well between the sample types, although CEA was more variable between the sample types for certain patients. The variability was not due to the time delay between EUS-FNA and OR collection or differences in total protein concentrations but may be caused by contamination of the cyst fluid with blood proteins. The classification of each patient based on thresholds for each marker was perfectly consistent between sample types for CA 19-9 and MUC5AC-WGA and mostly consistent for CEA. Therefore, results obtained using OR-collected pancreatic cyst fluid samples should reliably transfer to the clinical setting using EUS-FNA samples.
doi:10.1021/pr2012736
PMCID: PMC3345068  PMID: 22439797
5.  Longitudinal molecular imaging with single cell resolution of disseminated ovarian cancer in mice with a LED-based confocal microendoscope 
Purpose
We engineered a flexible fiber-optic microendoscope for longitudinal optical imaging studies in a mouse model of disseminated ovarian cancer.
Procedures
The microendoscope delivers 470 nm excitation light from a light-emitting diode through a fiber-optic bundle with outer diameter of 680 μm. Optics were optimized to maximize power and lateral resolution. We used this instrument to repetitively monitor intraperitoneal growth of HeyA8 ovarian cancer cells stably transduced with green fluorescent protein (GFP) over 4 weeks.
Results
The microendoscope achieves 0.7 mW power and lateral resolution of 4 μm. Initial in vivo imaging studies visualized single cells and small clusters of malignant cells with subsequent studies showing tumor masses and vasculature. We also resolved single cells within intraperitoneal tumor masses.
Conclusions
These studies establish microendoscope technology with single cell resolution for minimally-invasive, longitudinal imaging in living animals. This technology will advance future molecular imaging studies of ovarian cancer and other diseases.
doi:10.1007/s11307-010-0455-1
PMCID: PMC3502045  PMID: 21136184
Confocal; microscopy; fluorescence; in vivo; LED; fiber bundle; small animal imaging; ovarian cancer; xenograft; Zemax®
6.  Factors associated with esophageal stricture formation after endoscopic mucosal resection for neoplastic Barrett’s esophagus 
Gastrointestinal endoscopy  2011;74(4):753-760.
Background
EMR for early neoplastic Barrett’s esophagus is gaining favor over esophagectomy. Esophageal stricture development has been reported as a common complication of EMR, photodynamic therapy, and combination endoscopic therapy.
Objective
To determine clinical and procedural predictors of symptomatic stricture formation after EMR.
Design
Retrospective analysis.
Setting
Tertiary-care referral university hospital.
Patients
Data were retrospectively reviewed on 73 patients at our institution who underwent EMR monotherapy for Barrett’s esophagus with high-grade dysplasia or intramucosal cancer since January 2006.
Intervention
EMR.
Main Outcome Measurements
Symptomatic esophageal stricture formation.
Results
Symptomatic esophageal stricture formation was noted in 24.7% of patients undergoing EMR. Stricture formation on univariate analysis was associated with percentage of circumference of esophageal lumen resected, total pieces resected, number of EMR sessions, and tobacco use. A threshold effect was found at 50% of esophageal circumference resected (66.7% vs 27.2% developed strictures above and below the threshold, respectively; P = .004). A 25-pack-year or greater history of tobacco use had a threshold effect on esophageal stricture formation (77.8% vs 7.2% developed strictures above and below the threshold, respectively; P =.02). In multivariate analysis, resection of >50% of the circumference was strongly associated with stricture formation (odds ratio [OR] 4.17; 95% confidence interval [CI], 1.27–13.7). A 25-pack-year or greater history of tobacco use also trended toward stricture formation (OR 3.33; 95% CI, 0.929–12.1).
Limitations
Retrospective design, sample size.
Conclusion
Resection of at least 50% of the esophageal mucosal circumference is strongly associated with stricture formation. Patients with strong histories of tobacco use also may be more likely to develop esophageal strictures following EMR.
doi:10.1016/j.gie.2011.05.031
PMCID: PMC3481547  PMID: 21820109
7.  A Randomized Trial of Rectal Indomethacin to Prevent Post-ERCP Pancreatitis 
The New England Journal of Medicine  2012;366(15):1414-1422.
Background
Preliminary research suggests that rectally administered nonsteroidal antiinflammatory drugs may reduce the incidence of pancreatitis after endoscopic retrograde cholangiopancreatography (ERCP).
Methods
In this multicenter, randomized, placebo-controlled, double-blind clinical trial, we assigned patients at elevated risk for post-ERCP pancreatitis to receive a single dose of rectal indomethacin or placebo immediately after ERCP. Patients were determined to be at high risk on the basis of validated patient- and procedure-related risk factors. The primary outcome was post-ERCP pancreatitis, which was defined as new upper abdominal pain, an elevation in pancreatic enzymes to at least three times the upper limit of the normal range 24 hours after the procedure, and hospitalization for at least 2 nights.
Results
A total of 602 patients were enrolled and completed follow-up. The majority of patients (82%) had a clinical suspicion of sphincter of Oddi dysfunction. Post-ERCP pancreatitis developed in 27 of 295 patients (9.2%) in the indomethacin group and in 52 of 307 patients (16.9%) in the placebo group (P = 0.005). Moderate-to-severe pancreatitis developed in 13 patients (4.4%) in the indomethacin group and in 27 patients (8.8%) in the placebo group (P = 0.03).
Conclusions
Among patients at high risk for post-ERCP pancreatitis, rectal indomethacin significantly reduced the incidence of the condition. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT00820612.)
doi:10.1056/NEJMoa1111103
PMCID: PMC3339271  PMID: 22494121
8.  EUS and pancreatic cyst fluid analysis: Is the juice worth the aqueeze? 
doi:10.3978/j.issn.2078-6891.2011.042
PMCID: PMC3397625  PMID: 22811851

Results 1-8 (8)