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749 citation(s) found for "Xi, Dan".

PheKB: a catalog and workflow for creating electronic phenotype algorithms for transportability
Kirby, Jacqueline, Speltz, Peter, Rasmussen, Luke V. , Gottesman, Omri, Peissig, Peggy , Pacheco, Jennifer A. , Tromp, Gerard , Pathak, Jyotishman , Ellis, Stephen B. , Thompson, Will K, Savova, Guergana , Haines, Jonathan L. , Roden, Dan M. , Denny, Joshua C. , Basford, Melissa , Carrell, David , Lingren, Todd , Roden, Dan M. , Harris, Paul A. , Denny, Joshua C , Rasmussen, Luke V , Pacheco, Jennifer A

Mayo Clinic

Journal of the American Medical Informatics Association | March 30, 2016 | Volume: 23 | Issue: 6 | Pages: 1046-1052

10.1093/jamia/ocv202 | PMID 27026615 Get It

Abstract Objective Health care generated data have become an important source for clinical and genomic research. Often, investigators create and iteratively refine phenotype algorithms to achieve high positive predictive values (PPVs) or sensitivity, thereby identifying valid cases and controls. These algorithms achieve the greatest utility when validated and shared by multiple health care systems. Materials and Methods We report the current status and impact of the Phenotype KnowledgeBase (PheKB, http://phekb.org ), an online environment supporting the workflow of building, sharing, and validating electronic phenotype algorithms. We analyze the most frequent components used in algorithms and their performance at authoring institutions and secondary implementation sites. Results As of June 2015, PheKB contained 30 finalized phenotype algorithms and 62 algorithms in development spanning a range of traits and diseases. Phenotypes have had over 3500 unique views in a 6-month period and have been reused by other institutions. International Classification of Disease codes were the most frequently used component, followed by medications and natural language processing. Among algorithms with published performance data, the median PPV was nearly identical when evaluated at the authoring institutions (n = 44; case 96.0%, control 100%) compared to implementation sites (n = 40; case 97.5%, control 100%). Discussion These results demonstrate that a broad range of algorithms to mine electronic health record data from different health systems can be developed with high PPV, and algorithms developed at one site are generally transportable to others. Conclusion By providing a central repository, PheKB enables improved development, transportability, and validity of algorithms for research-grade phenotypes using health care generated data.
Activity of the oral mitogen‐activated protein kinase kinase inhibitor trametinib in RAS‐mutant relapsed or refractory myeloid malignancies
Popplewell, Leslie , Boyiadzis, Michael , Foran, James M. , Platzbecker, Uwe , Vey, Norbert , Walter, Roland B. , Olin, Rebecca L. , Raza, Azra , Giagounidis, Aristoteles , Al‐Kali, Aref , Kadia, Tapan M. , Garcia‐Manero, Guillermo , Bauman, John W., Wu, Yuehui , Liu, Yuan , Schramek, Dan, Cox, Donna S. , Wissel, Paul , Kantarjian, Hagop M. , Borthakur, Gautam , Jabbour, Elias , Platzbecker, Uwe , Walter, Roland B , Kantarjian, Hagop

Mayo Clinic

Cancer | March 19, 2016 | Volume: 122 | Issue: 12 | Pages: 1871-1879

10.1002/cncr.29986 | PMID 26990290 Get It

BACKGROUNDRAS/RAF/mitogen‐activated protein kinase activation is common in myeloid malignancies. Trametinib, a mitogen‐activated protein kinase kinase 1 (MEK1)/MEK2 inhibitor with activity against multiple myeloid cell lines at low nanomolar concentrations, was evaluated for safety and clinical activity in patients with relapsed/refractory leukemias.METHODSThis phase 1/2 study accrued patients with any relapsed/refractory leukemia in phase 1. In phase 2, this study accrued patients with relapsed/refractory acute myeloid leukemia (AML) or high‐risk myelodysplastic syndromes (MDS) with NRAS or KRAS mutations (cohort 1); patients with AML, MDS, or chronic myelomonocytic leukemia (CMML) with a RAS wild‐type mutation or an unknown mutation status (cohort 2); and patients with CMML with an NRAS or KRAS mutation (cohorts 3).RESULTSThe most commonly reported treatment‐related adverse events were diarrhea, rash, nausea, and increased alanine aminotransferase levels. The phase 2 recommended dose for Trametinib was 2 mg orally daily. The overall response rates were 20%, 3%, and 27% for cohorts 1, 2, and 3, respectively, and this indicated preferential activity among RAS‐mutated myeloid malignancies. Repeated cycles of trametinib were well tolerated with manageable or reversible toxicities; these results were similar to those of other trametinib studies.CONCLUSIONSThe selective, single‐agent activity of trametinib against RAS‐mutated myeloid malignancies validates its therapeutic potential. Combination strategies based on a better understanding of the hierarchical role of mutations and signaling in myeloid malignancies are likely to improve the response rate and duration. Cancer 2016;122:1871–9. © 2016 American Cancer Society.
Differential requirement for de novo lipogenesis in cholangiocarcinoma and hepatocellular carcinoma of mice and humans
Li, Lei , Che, Li , Tharp, Kevin M. , Pilo, Maria G., Cao, Dan , Cigliano, Antonio , Latte, Gavinella , Xu, Zhong , Ribback, Silvia , Dombrowski, Frank, Evert, Matthias , Stahl, Andreas , Chen, Xin , Park, Hyo‐Min , Gores, Gregory J. , Calvisi, Diego Francesco

Mayo Clinic

Hepatology | February 25, 2016 | Volume: 63 | Issue: 6 | Pages: 1900-1913

10.1002/hep.28508 | PMID 26910791 Get It

Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) are the most prevalent types of primary liver cancer. These malignancies have limited treatment options, resulting in poor patient outcomes. Metabolism reprogramming, including increased de novo lipogenesis, is one of the hallmarks of cancer. Fatty acid synthase (FASN) catalyzes the de novo synthesis of long‐chain fatty acids from acetyl‐coenzyme A and malonyl‐coenzyme A. Increased FASN expression has been reported in multiple tumor types, and inhibition of FASN expression has been shown to have tumor‐suppressing activity. Intriguingly, we found that while FASN is up‐regulated in human HCC samples, its expression is frequently low in human ICC specimens. Similar results were observed in mouse ICC models induced by different oncogenes. Ablating FASN in the mouse liver did not affect activated AKT and Notch (AKT/Notch intracellular domain 1) induced ICC formation in vivo. Furthermore, while both HCC and ICC lesions develop in mice following hydrodynamic injection of AKT and neuroblastoma Ras viral oncogene homolog oncogenes (AKT/Ras), deletion of FASN in AKT/Ras mice triggered the development almost exclusively of ICCs. In the absence of FASN, ICC cells might receive lipids for membrane synthesis through exogenous fatty acid uptake. In accordance with the latter hypothesis, ICC cells displayed high expression of fatty acid uptake‐related proteins and robust long‐chain fatty acid uptake. Conclusion: Our data demonstrate that FASN dependence is not a universal feature of liver tumors: while HCC development is highly dependent of FASN and its mediated lipogenesis, ICC tumorigenesis can be insensitive to FASN deprivation; our study supports novel therapeutic approaches to treat this pernicious tumor type with the inhibition of exogenous fatty acid uptake. (Hepatology 2016;63:1900‐1913)
The phenotypic legacy of admixture between modern humans and Neandertals
Simonti, Corinne , Vernot, Benjamin , Bastarache, Lisa , Böttinger, Erwin P. , Chisholm, Rex L. , Crosslin, David R. , Hebbring, Scott J. , Jarvik, Gail P. , Li, Rongling, Pathak, Jyotishman , Ritchie, Marylyn D. , Roden, Dan M. , Tromp, Gerard , Prato, Jeffrey D., Bush, William S. , Akey, Joshua M. , Denny, Joshua C. , Capra, John A. , Carrell, David , Kullo, Iftikhar J. , Roden, Dan M. , Verma, Shefali S. , Denny, Joshua C , Jarvik, Gail P , Bush, William S

Mayo Clinic

Science | February 12, 2016 | Volume: 351 | Issue: 6274 | Pages: 737-741

10.1126/science.aad2149 | PMID 26912863 Get It

The legacy of human-Neandertal interbreeding Non-African humans are estimated to have inherited on average 1.5 to 4% of their genomes from Neandertals. However, how this genetic legacy affects human traits is unknown. Simonti et al. combined genotyping data with electronic health records. Individual Neandertal alleles were correlated with clinically relevant phenotypes in individuals of European descent. These archaic genetic variants were associated with medical conditions affecting the skin, the blood, and the risk of depression. Science , this issue p. 737
PlGF/VEGFR-1 Signaling Promotes Macrophage Polarization and Accelerated Tumor Progression in Obesity
Incio, João , Tam, Josh, Rahbari, Nuh N. , Suboj, Priya, McManus, Dan T., Chin, Shan M. , Vardam, Trupti D., Batista, Ana , Babykutty, Suboj , Jung, Keehoon , Hato, Tai , Ligibel, Jennifer A. , Krop, Ian E. , Puchner, Stefan B., Schlett, Christopher L. , Hoffmman, Udo, Ancukiewicz, Marek, Shibuya, Masabumi , Carmeliet, Peter , Soares, Raquel , Duda, Dan G. , Jain, Rakesh K., Fukumura, Dai , Khachatryan, Anna , Jain, Rakesh K., Duda, Dan G

Mayo Clinic

Clinical Cancer Research | February 9, 2016 | Volume: 22 | Issue: 12 | Pages: 2993-3004

10.1158/1078-0432.ccr-15-1839 | PMID 26861455 Get It

Abstract Purpose: Obesity promotes pancreatic and breast cancer progression via mechanisms that are poorly understood. Although obesity is associated with increased systemic levels of placental growth factor (PlGF), the role of PlGF in obesity-induced tumor progression is not known. PlGF and its receptor VEGFR-1 have been shown to modulate tumor angiogenesis and promote tumor-associated macrophage (TAM) recruitment and activity. Here, we hypothesized that increased activity of PlGF/VEGFR-1 signaling mediates obesity-induced tumor progression by augmenting tumor angiogenesis and TAM recruitment/activity. Experimental Design: We established diet-induced obese mouse models of wild-type C57BL/6, VEGFR-1 tyrosine kinase (TK)-null, or PlGF-null mice, and evaluated the role of PlGF/VEGFR-1 signaling in pancreatic and breast cancer mouse models and in human samples. Results: We found that obesity increased TAM infiltration, tumor growth, and metastasis in pancreatic cancers, without affecting vessel density. Ablation of VEGFR-1 signaling prevented obesity-induced tumor progression and shifted the tumor immune environment toward an antitumor phenotype. Similar findings were observed in a breast cancer model. Obesity was associated with increased systemic PlGF, but not VEGF-A or VEGF-B, in pancreatic and breast cancer patients and in various mouse models of these cancers. Ablation of PlGF phenocopied the effects of VEGFR-1-TK deletion on tumors in obese mice. PlGF/VEGFR-1-TK deletion prevented weight gain in mice fed a high-fat diet, but exacerbated hyperinsulinemia. Addition of metformin not only normalized insulin levels but also enhanced antitumor immunity. Conclusions: Targeting PlGF/VEGFR-1 signaling reprograms the tumor immune microenvironment and inhibits obesity-induced acceleration of tumor progression. Clin Cancer Res; 22(12); 2993–3004. ©2016 AACR.
Novel Bloodless Potassium Determination Using a Signal‐Processed Single‐Lead ECG
Sapir, Yehu , Dugan, Jennifer , Ackerman, Michael J. , Asirvatham, Samuel J. , Striemer, Bryan L., Bukartyk, Jan , Bennet, Kevin E. , Ladewig, Dorothy J., Gilles, Emily J., Sadot, Dan , Geva, Amir B. , Friedman, Paul A. , Dillon, John J, Dugan, Jennifer L, Bruce, Charles J. , Attia, Zachi I. , DeSimone, Christopher V. , Dillon, John J., Somers, Virend K. , Scott, Christopher G. , Asirvatham, Samuel J

Mayo Clinic

Journal of the American Heart Association | January 25, 2016 | Volume: 5 | Issue: 1 | Pages: No page available

10.1161/jaha.115.002746 | PMID 26811164 Get It

Background Hyper‐ and hypokalemia are clinically silent, common in patients with renal or cardiac disease, and are life threatening. A noninvasive, unobtrusive, blood‐free method for tracking potassium would be an important clinical advance. Methods and Results Two groups of hemodialysis patients (development group, n=26; validation group, n=19) underwent high‐resolution digital ECG recordings and had 2 to 3 blood tests during dialysis. Using advanced signal processing, we developed a personalized regression model for each patient to noninvasively calculate potassium values during the second and third dialysis sessions using only the processed single‐channel ECG . In addition, by analyzing the entire development group's first‐visit data, we created a global model for all patients that was validated against subsequent sessions in the development group and in a separate validation group. This global model sought to predict potassium, based on the T wave characteristics, with no blood tests required. For the personalized model, we successfully calculated potassium values with an absolute error of 0.36±0.34 mmol/L (or 10% of the measured blood potassium). For the global model, potassium prediction was also accurate, with an absolute error of 0.44±0.47 mmol/L for the training group (or 11% of the measured blood potassium) and 0.5±0.42 for the validation set (or 12% of the measured blood potassium). Conclusions The signal‐processed ECG derived from a single lead can be used to calculate potassium values with clinically meaningful resolution using a strategy that requires no blood tests. This enables a cost‐effective, noninvasive, unobtrusive strategy for potassium assessment that can be used during remote monitoring.
P3‐169: Reduced default network functional connectivity and verbal learning in cognitively unimpaired late middle‐aged and older adults: Exploratory findings from the arizona ApoE cohort study
Beck, Irene , Roontiva, Auttawut, Wroolie, Tonita, Dunbar, Cole, Peshkin, Eric, Bandy, Dan, Rasgon, Nathalie, Caselli, Richard J. , Reiman, Eric M. , Chen, Kewei , Bauer, Robert , Peshkin, Eric

Mayo Clinic

Alzheimer's & Dementia | December 15, 2015 | Volume: 11 | Issue: 7S_Part_15 | Pages: No page available

10.1016/j.jalz.2015.06.1540 Get It

P2‐225: Utilizing primary family caregivers in delirium prevention in patients with pre‐existing dementia hospitalized with acute stroke
Sonchik, Sarah Z., Comer, Meghan R., Capampangan, Dan J.

Mayo Clinic

Alzheimer's & Dementia | December 15, 2015 | Volume: 11 | Issue: 7S_Part_12 | Pages: No page available

10.1016/j.jalz.2015.06.765 Get It

Identification and Functional Characterization of a Novel CACNA1C -Mediated Cardiac Disorder Characterized by Prolonged QT Intervals With Hypertrophic Cardiomyopathy, Congenital Heart Defects, and Sudden Cardi
Boczek, Nicole J. , Ye, Dan , Jin, Fang , Tester, David J. , Kelcher, April M. Huseby , Bos, J. Martijn , Johnson, Aaron J. , Kanter, Ronald J. , Ackerman, Michael J. , Huseby, April, Kanter, Ronald, Johnson, Aaron J. , Kelcher, April M H , Bos, Johan M

Mayo Clinic

Circulation: Arrhythmia and Electrophysiology | October 20, 2015 | Volume: 8 | Issue: 5 | Pages: 1122-1132

10.1161/circep.115.002745 | PMID 26253506 Get It

Background— A portion of sudden cardiac deaths can be attributed to structural heart diseases, such as hypertrophic cardiomyopathy (HCM) or cardiac channelopathies such as long-QT syndrome (LQTS); however, the underlying molecular mechanisms are distinct. Here, we identify a novel CACNA1C missense mutation with mixed loss-of-function/gain-of-function responsible for a complex phenotype of LQTS, HCM, sudden cardiac death, and congenital heart defects. Methods and Results— Whole exome sequencing in combination with Ingenuity variant analysis was completed on 3 affected individuals and 1 unaffected individual from a large pedigree with concomitant LQTS, HCM, and congenital heart defects and identified a novel CACNA1C mutation, p.Arg518Cys, as the most likely candidate mutation. Mutational analysis of exon 12 of CACNA1C was completed on 5 additional patients with a similar phenotype of LQTS plus a personal or family history of HCM-like phenotypes and identified 2 additional pedigrees with mutations at the same position, p.Arg518Cys/His. Whole cell patch clamp technique was used to assess the electrophysiological effects of the identified mutations in Ca V 1.2 and revealed a complex phenotype, including loss of current density and inactivation in combination with increased window and late current. Conclusions— Through whole exome sequencing and expanded cohort screening, we identified a novel genetic substrate p.Arg518Cys/His-CACNA1C, in patients with a complex phenotype including LQTS, HCM, and congenital heart defects annotated as cardiac-only Timothy syndrome. Our electrophysiological studies, identification of mutations at the same amino acid position in multiple pedigrees, and cosegregation with disease in these pedigrees provide evidence that p.Arg518Cys/His is the pathogenic substrate for the observed phenotype.