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476 citation(s) found for "Wallace, M".

Adenoma recurrence after endoscopic mucosal resection: propensity score analysis of old and new colonoscopes and Sydney recurrence tool implementation
Kandel, Pujan , Perez, Lady Mejia, Bingham, Russell, Lennon, Ryan J. , Woodward, Timothy A., Gómez, Victoria , Bouras, Ernest P., Wallace, Michael B. , Vinsard, Daniela Guerrero , Mejia Perez, Lady Katherine, Bingham, Russell L, Raimondo, Massimo , Wallace, Michael B , Pérez, Lady Katherine Mejía

Mayo Clinic

Endoscopy International Open | February 7, 2018 | Volume: 06 | Issue: 02 | Pages: E230-E241

10.1055/s-0043-122070 | PMID 29423433 Get It

Abstract Background and study aims Risk factors for colorectal adenoma recurrence after endoscopic mucosal resection (EMR) have been well documented. We assessed the efficacy of the newer 190 colonoscope versus the standard 180 colonoscope for complete resection of lateral spreading lesions. Patients and methods A single-center, retrospective study of patients who underwent EMR with Olympus 180 or 190 colonoscopes from January 1, 2010 to September 30, 2016. We included patients with lesions ≥ 20 mm and surveillance colonoscopy (SC1) after index EMR. A propensity score approach with inverse probability weighting was used to control for potential confounders. A secondary aim was to identify risk factors for recurrence and assess the applicability of the Sydney EMR recurrence tool (SERT) by grading each lesion of our cohort and analyzing associations with recurrence. Results Two hundred ninety-one lesions met inclusion criteria for the study. Odds ratio (OR) for recurrence with the 190 colonoscope was 1.06 (P = .85). Adenoma size (P = .02) and use of argon plasma coagulation (APC; P < .001) were risk factors for recurrence. Lesions with SERT scores > 0 had a higher recurrence risk during follow-up (32 % vs 21 %; OR 1.71; P = .05). Lesions with SERT scores = 0 reached a plateau for recurrence at 12 and 18 months in Kaplan-Meier curves. Conclusions The use of 190 colonoscopes did not measurably affect adenoma recurrence at SC1. Recurrence was associated with adenoma size, complementary APC for resection, and SERT scores > 0. Lesions with SERT scores = 0 that remain negative for recurrence at 18 months may return to routine surveillance.
Learning curve and competence for volumetric laser endomicroscopy in Barrett’s esophagus using cumulative sum analysis
Inamdar, Sumant , Smith, Michael S. , Rosen, Lisa, Han, Dennis , Chang, Kenneth J. , Leggett, Cadman, Lightdale, Charles J. , Sejpal, Divyesh V., Tearney, Guillermo J. , Thomas, Rebecca, Wallace, Michael B. , Leggett, Cadman L. , Wallace, Michael B , Trindade, Arvind J. , Pleskow, Douglas K. , Leggett, Cadman L

Mayo Clinic

Endoscopy | November 27, 2017 | Volume: 50 | Issue: 05 | Pages: 471-478

10.1055/s-0043-121569 | PMID 29179229 Get It

Abstract Background and study aims Little is known about the learning curve for image interpretation in volumetric laser endomicroscopy (VLE) in Barrett’s esophagus (BE). The goal of this study was to calculate the learning curve, competence of image interpretation, sensitivity, specificity, and accuracy of VLE among novice users. Methods 31 novice users viewed 96 VLE images electronically at three academic institutions after a brief training session. There were 24 images of each histologic type: normal gastric cardia, normal esophageal squamous epithelium, non-neoplastic BE, and neoplastic BE. The users were asked to identify the correct tissue type and level of confidence. The cumulative summation (CUSUM) technique was used to construct a learning curve. Results 22 (71 %) of the physicians achieved VLE interpretation competency during their 96-slide review. Half of the physicians achieved competency at 65 images (95 % confidence interval [CI] 45 – 85). There was a statistically significant association between confidence in diagnosis and selecting the correct histologic tissue type (P < 0.001). The median accuracy for esophageal squamous epithelium, normal gastric cardia, non-neoplastic BE, and neoplastic BE was 96 % (95 %CI 95 % – 96 %), 95 % (95 %CI 94 % – 96 %), 90 % (95 %CI 88 % – 91 %), 96 % (95 %CI 95 % – 96 %). The overall accuracy was 95 % (95 %CI 93 % – 95 %). Conclusion The majority of novice users achieved competence in image interpretation of VLE for BE, using a pre-selected image set, with a favorable learning curve after a brief training session. An electronic review of VLE images, prior to real-time use of VLE, is encouraged.
Development of an in vivo mouse model of discogenic low back pain
Shi, Changgui , Das, Vaskar, Li, Xin , Kc, Ranjan , Qiu, Sujun , O‐Sullivan, InSug , Ripper, Richard, Kroin, Jeffrey S., Mwale, Fackson , Wallace, Atiyayein A., Zhu, Bingqian , Wijnen, André J. van , Ji, Ming-liang , Lü, Jun , Votta‐Velis, Gina , Yuan, Wen, Im, Hee‐Jeong , van Wijnen, Andre J , Zhao, Lan , Yuan, Wen

Mayo Clinic

Journal of Cellular Physiology | November 18, 2017 | Volume: 233 | Issue: 10 | Pages: 6589-6602

10.1002/jcp.26280 | PMID 29150945 Get It

Discogenic low back pain (DLBP) is extremely common and costly. Effective treatments are lacking due to DLBP's unknown pathogenesis. Currently, there are no in vivo mouse models of DLBP, which restricts research in this field. The aim of this study was to establish a reliable DLBP model in mouse that captures the pathological changes in the disc and allows longitudinal pain testing. The model was generated by puncturing the mouse lumbar discs (L4/5, L5/6, and L6/S1) and removing the nucleus pulposus using a microscalpel under the microscope. Histology, molecular pathways, and pain‐related behaviors were examined. Over 12 weeks post‐surgery, animals displayed the mechanical, heat, and cold hyperalgesia along with decreased burrowing and rearing. Histology showed progressive disc degeneration with loss of disc height, nucleus pulposus reduction, proteoglycan depletion, and annular fibrotic disorganization. Immunohistochemistry revealed a substantial increase in inflammatory mediators at 2 and 4 weeks. Nerve growth factor was upregulated from 2 weeks to the end of the experiment. Nerve fiber ingrowth was induced in the injured discs after 4 weeks. Disc‐puncture also produced an upregulation of neuropeptides in dorsal root ganglia neurons and an activation of glial cells in the spinal cord dorsal horn. These findings indicate that the cellular and structural changes in discs, as well as peripheral and central nervous system plasticity, paralleled persistent, and robust behavioral pain responses. Therefore, this mouse DLBP model could be used to investigate mechanisms underlying discogenic pain, thereby facilitating effective drug screening and development of treatments for DLBP.
Animal models for studying the etiology and treatment of low back pain
Shi, Changgui , Qiu, Sujun , Riester, Scott M. , Das, Vaskar, Zhu, Bingqian , Wallace, Atiyayein A., Wijnen, André J. van , Mwale, Fackson , Iatridis, James C. , Sakai, Daisuke , Votta‐Velis, Gina , Yuan, Wen, Im, Hee‐Jeong , van Wijnen, Andre J , Iatridis, James C , Yuan, Wen

Mayo Clinic

Journal of Orthopaedic Research | September 18, 2017 | Volume: 36 | Issue: 5 | Pages: 1305-1312

10.1002/jor.23741 | PMID 28921656 Get It

ABSTRACTChronic low back pain is a major cause of disability and health care costs. Effective treatments are inadequate for many patients. Animal models are essential to further understanding of the pain mechanism and testing potential therapies. Currently, a number of preclinical models have been developed attempting to mimic aspects of clinical conditions that contribute to low back pain (LBP). This review focused on describing these animal models and the main behavioral tests for assessing pain in each model. Animal models of LBP can be divided into the following five categories: Discogenic LBP, radicular back pain, facet joint osteoarthritis back pain, muscle‐induced LBP, and spontaneous occurring LBP models. These models are important not only for enhancing our knowledge of how LBP is generated, but also for the development of novel therapeutic regimens to treat LBP in patients. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1305–1312, 2018.
Using Naïve Bayesian Analysis to Determine Imaging Characteristics of KRAS Mutations in Metastatic Colon Cancer
Pershad, Yash , Govindan, Siddharth, Hara, Amy K., Bekaii‐Saab, Tanios , Wallace, Alex, Albadawi, Hassan , Öklü, Rahmi , Oklu, Rahmi , Bekaii-Saab, Tanios S , Borad, Mitesh J.

Mayo Clinic

Diagnostics | September 4, 2017 | Volume: 7 | Issue: 3 | Pages: 50

10.3390/diagnostics7030050 | PMID 28869500 Get It

Genotype, particularly Ras status, greatly affects prognosis and treatment of liver metastasis in colon cancer patients. This pilot aimed to apply word frequency analysis and a naive Bayes classifier on radiology reports to extract distinguishing imaging descriptors of wild-type colon cancer patients and those with v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations. In this institutional-review-board-approved study, we compiled a SNaPshot mutation analysis dataset from 457 colon adenocarcinoma patients. From this cohort of patients, we analyzed radiology reports of 299 patients (> 32,000 reports) who either were wild-type (147 patients) or had a KRAS (152 patients) mutation. Our algorithm determined word frequency within the wild-type and mutant radiology reports and used a naive Bayes classifier to determine the probability of a given word belonging to either group. The classifier determined that words with a greater than 50% chance of being in the KRAS mutation group and which had the highest absolute probability difference compared to the wild-type group included: “several”, “innumerable”, “confluent”, and “numerous” (p < 0.01). In contrast, words with a greater than 50% chance of being in the wild type group and with the highest absolute probability difference included: “few”, “discrete”, and “[no] recurrent” (p = 0.03). Words used in radiology reports, which have direct implications on disease course, tumor burden, and therapy, appear with differing frequency in patients with KRAS mutations versus wild-type colon adenocarcinoma. Moreover, likely characteristic imaging traits of mutant tumors make probabilistic word analysis useful in identifying unique characteristics and disease course, with applications ranging from radiology and pathology reports to clinical notes.
Applications of Endoscopic Ultrasonography in Pancreatic Cancer
Varadarajulu, Shyam, Wallace, Michael B. , Wallace, Michael B

Mayo Clinic

Cancer Control | August 30, 2017 | Volume: 11 | Issue: 1 | Pages: 15-22

10.1177/107327480401100103 | PMID 14749619 Get It

Background Accurate staging of pancreatic cancer is essential for surgical planning and for identification of locally advanced and metastatic disease that is incurable by surgery. Advances in endoscopic sonography (EUS), computed tomography (CT), and positron emission tomography have improved the accuracy of staging and reduced the number of incomplete surgical resections. Tissue acquisition is necessary in nonsurgical cases when chemoradiotherapy is considered. The complex regional anatomy of the pancreas makes cytologic diagnosis of malignancy at this region difficult without exploratory surgery. Although CT-guided fine-needle aspiration (FNA) is used for this purpose, reports of an increased risk of peritoneal dissemination of cancer cells and a false-negative rate of nearly 20% make this a poor choice. The ability to position the EUS-transducer in direct proximity to the pancreas by means of the stomach and duodenum, combined with the use of FNA, increases the specificity of EUS in detecting pancreatic malignancies. Methods The current literature regarding the accuracy of EUS with FNA in the evaluation of pancreatic cancer is reviewed. Results EUS accuracy ranges from 78% to 94% for tumor staging and from 64% to 82% for nodal staging. EUS also enables FNA of lesions that are too small to be identified by CT or MRI or too well encased by surrounding vascular structures to safely allow percutaneous biopsy. The accuracy for detecting invasion into the superior mesenteric artery and vein is lower than that for detecting portal or splenic vein invasion, especially for large tumors. EUS permits delivery of localized therapy such as celiac plexus neurolysis for pain control and direct intra-lesional injection of antitumor therapy. Conclusions EUS in combination with FNA is a highly accurate method of preoperative staging of pancreatic cancer, especially those too small to be characterized by CT or MRI, and it has the ability to obtain cytological confirmation of pancreatic cancer.
“Seek and you shall find” The Bible, Matthew 7:7
Werlang, Monia E., Francis, Dawn L., Wallace, Michael B. , Wallace, Michael B

Mayo Clinic

Endoscopy | July 26, 2017 | Volume: 49 | Issue: 08 | Pages: 729-731

10.1055/s-0043-110669 | PMID 28746963 Get It

Bacterial Endocarditis as a Complication of Transurethral Prostatic Resection
Merritt, Wallace A.

Mayo Clinic

Journal of Urology | June 30, 2017 | Volume: 65 | Issue: 1 | Pages: 100-107

10.1016/s0022-5347(17)68464-7 | PMID 14804770 Get It

Nephrolithiasis Complicating Chronic Ulcerative Colitis after Ileostomy: A Report of Six Cases
Lindahl, Wallace W., Bargen, J. Arnold

Mayo Clinic

Journal of Urology | June 29, 2017 | Volume: 46 | Issue: 2 | Pages: 183-192

10.1016/s0022-5347(17)70907-x Get It

Incidence of hematologic malignancy and cause‐specific mortality in the Women's Health Initiative randomized controlled trial of calcium and vitamin D supplementation
Ammann, Eric M. , Haraldsson, Bjarni , Wallace, Robert B. , Johnson, Karen , Lin, Emily M., Link, Brian K. , Drake, Matthew T. , Haraldsson, Bjarni , Desai, Pinkal , Link, Brian K

Mayo Clinic

Cancer | June 27, 2017 | Volume: 123 | Issue: 21 | Pages: 4168-4177

10.1002/cncr.30858 | PMID 28654155 Get It

BACKGROUNDPrior evidence of a possible link between vitamin D status and hematologic malignancy (HM) in humans comes from observational studies, leaving unresolved the question of whether a true causal relationship exists.METHODSThe authors performed a secondary analysis of data from the Women's Health Initiative Calcium/Vitamin D (CaD) trial, a large randomized controlled trial of CaD supplementation compared with placebo in older women. Kaplan‐Meier and Cox proportional hazards survival analysis methods were used to evaluate the relationship between treatment assignment and 1) incident HM and 2) HM‐specific mortality over 10 years following randomization. HMs were classified by cell type (lymphoid, myeloid, or plasma cell) and analyzed as distinct endpoints in secondary analyses.RESULTSA total of 34,763 Women's Health Initiative CaD trial participants (median age, 63 years) had complete baseline covariate data and were eligible for analysis. Women assigned to CaD supplementation had a significantly lower risk of incident HM (hazard ratio [HR], 0.80; 95% confidence interval [95% CI], 0.65‐0.99) but not HM‐specific mortality (HR, 0.77 [95% CI, 0.53‐1.11] for the entire cohort; and HR, 1.03 [95% CI, 0.70‐1.51] among incident HM cases after diagnosis). In secondary analyses, protective associations were found to be most robust for lymphoid malignancies, with HRs of 0.77 (95% CI, 0.59‐1.01) and 0.46 (95% CI, 0.24‐0.89), respectively, for cancer incidence and mortality in those assigned to CaD supplementation.CONCLUSIONSThe current post hoc analysis of data from a large and well‐executed randomized controlled trial demonstrates a protective association between modest CaD supplementation and HM risk in older women. Additional research concerning the relationship between vitamin D and HM is warranted. Cancer 2017;123:4168–4177. © 2017 American Cancer Society.