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3501 citation(s) found for "Xu, Timothy".

Recessive MYH6 Mutations in Hypoplastic Left Heart With Reduced Ejection Fraction
Theis, Jeanne L. , Zimmermann, Michael T. , Evans, Jared M., Eckloff, Bruce W., Wieben, Eric D. , Qureshi, M. Yasir , Olson, Timothy M. , Qureshi, Muhammad Y, O'Leary, Patrick W, O’Leary, Patrick , Qureshi, Muhammad Y , Zimmermann, Michael T , Theis, Jeanne L , Olson, Timothy M

Circulation: Cardiovascular Genetics | June 18, 2015 | Volume: 8 | Issue: 4 | Pages: 564-571

10.1161/circgenetics.115.001070 | PMID 26085007 Get It

Background— The molecular underpinnings of hypoplastic left heart are poorly understood. Staged surgical palliation has dramatically improved survival, yet eventual failure of the systemic right ventricle necessitates cardiac transplantation in a subset of patients. We sought to identify genetic determinants of hypoplastic left heart with latent right ventricular dysfunction in individuals with a Fontan circulation. Methods and Results— Evaluation of cardiac structure and function by echocardiography in patients with hypoplastic left heart and their first-degree relatives identified 5 individuals with right ventricular ejection fraction ≤40% after Fontan operation. Whole genome sequencing was performed on DNA from 21 family members, filtering for genetic variants with allele frequency <1% predicted to alter protein structure or expression. Secondary family-based filtering for de novo and recessive variants revealed rare inherited missense mutations on both paternal and maternal alleles of MYH6 , encoding myosin heavy chain 6, in 2 patients who developed right ventricular dysfunction 3 to 11 years postoperatively. Parents and siblings who were heterozygous carriers had normal echocardiograms. Protein modeling of the 4 highly conserved amino acid substitutions, residing in both head and tail domains, predicted perturbation of protein structure and function. Conclusions— In contrast to dominant MYH6 mutations with variable penetrance identified in other congenital heart defects and dilated cardiomyopathy, this study reveals compound heterozygosity for recessive MYH6 mutations in patients with hypoplastic left heart and reduced systemic right ventricular ejection fraction. These findings implicate a shared molecular basis for the developmental arrest and latent myopathy of left and right ventricles, respectively.
Global and local ancestry in African‐Americans: Implications for Alzheimer's disease risk
Hohman, Timothy J. , Bailey, Jessica N. Cooke , Reitz, Christiane , Jun, Gyungah , Beecham, Gary W. , Carney, Regina M., Vance, Jeffery M. , Rajbhandary, Ruchita, Lin, Chiao‐Feng , Larson, Eric B., Graff‐Radford, Neill R. , Evans, Denis A., Jager, Philip L. De , Crane, Paul K. , Buxbaum, Joseph D. , Murrell, Jill R. , Raj, Towfique , Ertekin‐Taner, Nilüfer , Baldwin, Clinton T., Green, Robert C. , Barnes, Lisa L. , Cantwell, Laura B., Fallin, M. Daniele , Go, Rodney C.P., Griffith, Patrick , Obisesan, Thomas O. , Lunetta, Kathryn L. , Kamboh, M. Ilyas , Bennett, David A. , Hardy, John , Hendrie, Hugh C. , Hall, Kathleen, Goate, Alison , Lang, Rosalyn, Byrd, Goldie S. , Kukull, Walter A. , Farrer, Lindsay A. , Martin, Eden R. , Pericak‐Vance, Margaret A. , Schellenberg, Gerard D. , Mayeux, Richard , Haines, Jonathan L. , Thornton‐Wells, Tricia A., Carroll, Steven L. , Bennett, David A. , Naj, Adam Christian , Liu, Zhi , Cuccaro, Michael L. , Vardarajan, Badri Narayan , Wang, Weixin , Valladares, Otto , Logue, Mark W. , Manly, Jennifer J. , López, Oscar L. , Foroud, Tatiana , Seto, Mabel , Hardy, John , Goate, Alison M , Barnes, Lisa L

Alzheimer's & Dementia | June 16, 2015 | Volume: 12 | Issue: 3 | Pages: 233-243

10.1016/j.jalz.2015.02.012 | PMID 26092349 Get It

AbstractIntroductionAfrican‐American (AA) individuals have a higher risk for late‐onset Alzheimer's disease (LOAD) than Americans of primarily European ancestry (EA). Recently, the largest genome‐wide association study in AAs to date confirmed that six of the Alzheimer's disease (AD)‐related genetic variants originally discovered in EA cohorts are also risk variants in AA; however, the risk attributable to many of the loci (e.g., APOE, ABCA7) differed substantially from previous studies in EA. There likely are risk variants of higher frequency in AAs that have not been discovered.MethodsWe performed a comprehensive analysis of genetically determined local and global ancestry in AAs with regard to LOAD status.ResultsCompared to controls, LOAD cases showed higher levels of African ancestry, both globally and at several LOAD relevant loci, which explained risk for AD beyond global differences.DiscussionExploratory post hoc analyses highlight regions with greatest differences in ancestry as potential candidate regions for future genetic analyses.
MRI Findings in Nonlesional Hypertrophic Olivary Degeneration
Gu, Chris N., Wood, Christopher P. , Carr, Carrie M. , Kotsenas, Amy L. , Hunt, Christopher H. , Kaufmann, Timothy J.

Journal of Neuroimaging | June 15, 2015 | Volume: 25 | Issue: 5 | Pages: 813-817

10.1111/jon.12267 | PMID 26073621 Get It

ABSTRACTPURPOSEInvestigate the relative frequency of nonlesional versus lesional hypertrophic olivary degeneration (HOD) and potential explanations for nonlesional HOD.METHODSOur radiology report database was queried for “HOD” in all head MRI reports between 7/1/2002 and 7/1/2013 and identified 138 patients. Specific absence of HOD or cases with lesions within the dento‐rubro‐olivary pathway (DROP) or extending into the inferior olivary nuclei (ION) were excluded (22 in total). For included patients, 19 locations with the anatomic potential to connect to the ION or DROP were reviewed and grouped into embryological categories, along with the use of the drug metronidazole.RESULTSA total of 51 of 116 (44%) HOD patients did not have a causative lesion in the DROP. The 27/51 (53%) of these patients had progressive ataxia with palatal tremor (PAPT). The 28/51 (55%) patients had one or more lesions outside of the DROP and one of these 28 patients used metronidazole. The remaining 23/51 (45%; 19% of total HOD cohort) patients had no additional lesions in the brain and 6 of these 23 patients did not have a clinical diagnosis of PAPT.CONCLUSIONForty‐four percent of patients with HOD did not demonstrate an MRI‐identifiable lesion in the DROP, and 45% of those patients did not have identifiable brain lesions outside of the DROP. Thus, nearly a fifth of HOD cases may be truly idiopathic. A majority of patients without a DROP lesion had bilateral HOD and two‐thirds were male.
Volumetric computed tomography analysis of the olfactory cleft in patients with chronic rhinosinusitis
Pallanch, John F., Sansoni, E. Ritter, Jones, Cameron , Lawrence, Lauren A., Schlosser, Rodney J. , Mace, Jess C. , Smith, Timothy L. , Soler, Zachary M. , Schlosser, Rodney J

International Forum of Allergy & Rhinology | May 26, 2015 | Volume: 5 | Issue: 9 | Pages: 846-854

10.1002/alr.21552 | PMID 26010298 Get It

BackgroundCommonly used computed tomography (CT) staging systems for chronic rhinosinusitis (CRS) focus on the sinuses and do not quantify disease in the olfactory cleft. The goal of the current study was to determine whether precise measurements of olfactory cleft opacification better correlate with olfaction in patients with CRS.MethodsOlfaction was assessed using the 40‐item Smell Identification Test (SIT‐40) before and after sinus surgery in adult patients. Olfactory cleft opacification was quantified precisely using three‐dimensional (3D), computerized volumetric analysis, as well as via semiquantitative Likert scale estimations at predetermined anatomic sites. Sinus opacification was also quantified using the Lund‐Mackay staging system.ResultsThe overall cohort (n = 199) included 89 (44.7%) patients with CRS with nasal polyposis (CRSwNP) and 110 (55.3%) with CRS without nasal polyposis (CRSsNP). The olfactory cleft opacified volume correlated with objective olfaction as determined by the SIT‐40 (Spearman's rank correlation coefficient [Rs] = −0.461; p < 0.001). The correlation was significantly stronger in the CRSwNP subgroup (Rs = −0.573; p < 0.001), whereas no appreciable correlation was found in the CRSsNP group (Rs = −0.141; p = 0.141). Correlations between sinus‐specific Lund‐Mackay CT scoring and SIT‐40 scores were weaker in the CRSwNP (Rs = −0.377; p < 0.001) subgroup but stronger in the CRSsNP (Rs = −0.225; p = 0.018) group when compared to olfactory cleft correlations. Greater intraclass correlations (ICCs) were found between quantitative volumetric measures of olfactory cleft opacification (ICC = 0.844; p < 0.001) as compared with semiquantitative Likert grading (ICC = 0.627; p < 0.001).ConclusionQuantitative measures of olfactory cleft opacification correlate with objective olfaction, with the strongest correlations seen in patients with nasal polyps.
Impact of Ibrutinib and Idelalisib on the Pharmaceutical Cost of Treating Chronic Lymphocytic Leukemia at the Individual and Societal Levels
Finnes, Heidi D. , Chaffee, Kari G. , Leis, José F., Chanan‐Khan, Asher , Call, Tim G., Rabe, Kari G. , Borah, Bijan J. , Chanan-Khan, Asher A., Shanafelt, Tait D. , Ding, Wei , Parikh, Sameer A. , Slager, Susan L. , Kay, Neil E. , Call, Timothy G.

Journal of Oncology Practice | May 15, 2015 | Volume: 11 | Issue: 3 | Pages: 252-258

10.1200/jop.2014.002469 | PMID 25804983 Get It

Although ibrutinib and idelalisib are profound treatment advances, they will dramatically increase individual out-of-pocket and societal costs of caring for patients with CLL.
Utilizing magnetization transfer imaging to investigate tissue remodeling in a murine model of autosomal dominant polycystic kidney disease
Kline, Timothy L. , Irazabal, María V. , Ebrahimi, Behzad , Udoji, Kelly N., Warner, Joshua , Korfiatis, Panagiotis , Mishra, Prasanna K. , Venkatesh, Sudhakar K. , Lerman, Lilach O. , Harris, Peter C. , Torres, Vicente E. , King, Bernard F., Hopp, Katharina , Warner, Joshua D, Macura, Slobodan I, Macura, Slobodan , Erickson, Bradley J. , Harris, Peter C , Torres, Vicente E , Venkatesh, Sudhakar K , Irazabal, Maria V

Magnetic Resonance in Medicine | May 14, 2015 | Volume: 75 | Issue: 4 | Pages: 1466-1473

10.1002/mrm.25701 | PMID 25974140 Get It

PurposeNoninvasive imaging techniques that quantify renal tissue composition are needed to more accurately ascertain prognosis and monitor disease progression in polycystic kidney disease (PKD). Given the success of magnetization transfer (MT) imaging to characterize various tissue remodeling pathologies, it was tested on a murine model of autosomal dominant PKD.MethodsC57Bl/6 Pkd1 R3277C mice at 9, 12, and 15 months were imaged with a 16.4T MR imaging system. Images were acquired without and with RF saturation in order to calculate MT ratio (MTR) maps. Following imaging, the mice were euthanized and kidney sections were analyzed for cystic and fibrotic indices, which were compared with statistical parameters of the MTR maps.ResultsThe MTR‐derived mean, median, 25th percentile, skewness, and kurtosis were all closely related to indices of renal pathology, including kidney weight/body weight, cystic index, and percent of remaining parenchyma. The correlation between MTR and histology‐derived cystic and fibrotic changes was R2 = 0.84 and R2 = 0.70, respectively.ConclusionMT imaging provides a new, noninvasive means of measuring tissue remodeling PKD changes and may be better suited for characterizing renal impairment compared with conventional MR techniques. Magn Reson Med 75:1466–1473, 2016. © 2015 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance.
Regenerative Therapy Prevents Heart Failure Progression in Dyssynchronous Nonischemic Narrow QRS Cardiomyopathy
Arrell, D. Kent , Martinez‐Fernandez, Almudena , Behfar, Atta , Kane, Garvan C. , Pérez-Terzic, Carmen, Crespo‐Diaz, Ruben , McDonald, Robert J. , Wyles, Saranya P. , Zlatkovic‐Lindor, Jelena, Yamada, Satsuki , Martinez-Fernandez, Almudena, Perez-Terzic, Carmen M, Crespo-Diaz, Ruben J, Zlatkovic-Lindor, Jelena, Nelson, Timothy J. , Terzic, André , Behfar, Atta

Journal of the American Heart Association | May 12, 2015 | Volume: 4 | Issue: 5 | Pages: No page available

10.1161/jaha.114.001614 | PMID 25964205 Get It

Background Cardiac resynchronization therapy using bi‐ventricular pacing is proven effective in the management of heart failure (HF) with a wide QRS ‐complex. In the absence of QRS prolongation, however, device‐based resynchronization is reported unsuitable. As an alternative, the present study tests a regenerative cell‐based approach in the setting of narrow QRS ‐complex HF. Methods and Results Progressive cardiac dyssynchrony was provoked in a chronic transgenic model of stress‐triggered dilated cardiomyopathy. In contrast to rampant end‐stage disease afflicting untreated cohorts, stem cell intervention early in disease, characterized by mechanical dyssynchrony and a narrow QRS ‐complex, aborted progressive dyssynchronous HF and prevented QRS widening. Stem cell‐treated hearts acquired coordinated ventricular contraction and relaxation supporting systolic and diastolic performance. Rescue of contractile dynamics was underpinned by a halted left ventricular dilatation, limited hypertrophy, and reduced fibrosis. Reverse remodeling reflected a restored cardiomyopathic proteome, enforced at systems level through correction of the pathological molecular landscape and nullified adverse cardiac outcomes. Cell therapy of a dyssynchrony‐prone cardiomyopathic cohort translated prospectively into improved exercise capacity and prolonged survivorship. Conclusions In narrow QRS HF, a regenerative approach demonstrated functional and structural benefit, introducing the prospect of device‐autonomous resynchronization therapy for refractory disease.
Abstract 274: Occupational exposure to agricultural pesticides and CLL risk
Hallberg, Emily J., Achenbach, Sara J., Call, Timothy G. , Allmer, Cristine, Liebow, Mark , Rabe, Kari G. , Shanafelt, Tait D. , Kay, Neil E. , Cerhan, James R. , Slager, Susan L.

Cancer Research | May 4, 2015 | Volume: 74 | Issue: 19_Supplement | Pages: 274-274

10.1158/1538-7445.am2014-274 Get It

Abstract Background Previous literature regarding the association between occupational exposure to agricultural pesticides and non-Hodgkin lymphoma (NHL) risk has been inconsistent, particularly when looking at specific lymphoma subtypes. Most recently, a large European case-control study showed an elevated risk of chronic lymphocytic leukemia (CLL) among those ever exposed to inorganic and organic pesticides with the strongest association among those exposed to organophosphates. However, when restricting the analysis to subjects with high confidence of exposure, these associations were attenuated (Cocco P., 2013). We used case-control data from the Mayo Clinic to evaluate whether there is an increased risk of CLL among individuals with known occupational exposure to agricultural pesticides. Methods We evaluated pesticide exposure and CLL risk in a clinic-based study of newly diagnosed CLL cases and frequency-matched controls enrolled at the Mayo Clinic from 2002-2012. 200 CLL cases and 474 controls returned a detailed farming and pesticide exposure questionnaire that was modeled after the Agricultural Health Study, where exposure was based on pesticide-specific application. Unconditional logistic regression, adjusted for age and sex, was used to estimate odds ratios (ORs) and 95% confidence intervals (CI). We evaluated the effect of each pesticide individually, by chemical class of pesticides, and by an aggregate of multiple pesticide exposure on CLL risk. Results Among those participants with detailed farming data, the mean age of CLL diagnosis was 66 years and 76% were male; for controls, the mean age at enrollment was 65 years and 66% were male. Risk of CLL was mildly elevated, but not significant, amongst those with application of any pesticide (OR 1.39; 95% C.I. 0.92-2.10). When broken down by chemical class, risk of CLL was also mildly elevated, but not significant, for application of organophosphates and carbamates (OR 1.21; 95% CI 0.84-1.73; OR 1.21; 95% 0.85-1.73, respectively). Organochlorines, phenoxy compounds, pyrethriods and triazines showed no evidence of an elevated risk, nor did we see evidence of a trend that CLL risk increases with number of pesticides applied. Discussion Our preliminary results provide inconclusive support for the role of pesticide exposure as a possible risk factor for CLL. However our sample size was small. Additional data will be incorporated, including confidence of exposure measures, as well as other modifying factors, to further evaluate these results. Citation Format: Emily J. Hallberg, Sara J. Achenbach, Kari G. Rabe, Timothy G. Call, Cristine Allmer, Tait D. Shanafelt, Mark Liebow, Neil E. Kay, James R. Cerhan, Susan L. Slager. Occupational exposure to agricultural pesticides and CLL risk. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 274. doi:10.1158/1538-7445.AM2014-274
Abstract 2713: Small-molecule FASN inhibitors promote growth inhibition growth and apoptosis of breast cancer
Lupu, Ruth , Guerrico, Anatilde González, Khurana, Ashwani, Heuer, Timothy S., Kemble, George, KVP, Chandra Mohan

Cancer Research | May 4, 2015 | Volume: 74 | Issue: 19_Supplement | Pages: 2713-2713

10.1158/1538-7445.am2014-2713 Get It

Abstract Increased de novo lipogenesis due to enhanced expression of several lipogenic enzymes has been found in many types of human cancers. Fatty acid synthase (FASN), the key enzyme in the de novo lipogenesis pathway, is one of the most commonly over-expressed lipogenic enzymes. Studies in the past decade have recognized FASN overexpression as a molecular marker for poor prognosis and malignant phenotype of many cancers. Tumor-associated FASN, by conferring growth and survival advantages rather than functioning as an anabolic energy-storage pathway, has also been suggested to play an active part in the development, maintenance, and metastatic progression of human cancers. More recently, FASN has been implicated in contributing to cellular resistance to several anticancer treatments. A variety of agents have been developed to target lipogenic enzymes and the key regulators involved in lipid metabolism in cancer cell for therapeutic purposes. The development of several FASN inhibitors has been reported from both academic labs and industries. When used in in vitro, xenograft and genetically induced mouse model studies, these inhibitors have supported FASN as an excellent target. A new generation of FASN inhibitors was developed at 3-V Biosciences that are highly specific, reversible inhibitors of FASN. One compound in this series, TVB-2640, is orally bioavailable and has progressed into Phase 1 clinical studies. The effect of two anti-FASN drugs in this series, TVB-3150 and TVB-3199 were tested for their effect on breast cancer cells. We demonstrated that the EC50 is between 9-50 nM, depending on the drug and the tested cell line. We then demonstrated that the drugs inhibited the anchorage-dependent and -independent growth of FASN expressing cells in a dose dependent manner. The apparent mechanism by which the FASN inhibitors promote inhibition of growth is by inducing apoptotic cell death in a time- and dose-dependent manner that involves regulation of apoptotic and pro-apoptotic proteins. Furthermore, the combination of the anti-FASN drugs with small molecule inhibitors of the antiapoptotic proteins Bcl-2 and Bcl-xL significantly increased the apoptotic effect in a synergistic manner compared to either of the synthetic inhibitors alone. In vivo studies demonstrate tumor growth inhibition without toxicity. Clinical development of a first-in-class, orally active, potent, and reversible FASN inhibitor as a novel cancer therapeutic is ongoing. Citation Format: Ruth Lupu, Anatilde Gonzalez Guerrico, Ashwani Khurana, Timothy Heuer, George Kemble, Chandra Mohan KVP. Small-molecule FASN inhibitors promote growth inhibition growth and apoptosis of breast cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2713. doi:10.1158/1538-7445.AM2014-2713