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58 citation(s) found for "Viswanathan, A".

Cytomorphology and sonographic features of ectopic thymic tissue diagnosed in paediatric FNA biopsies
Escobar, Fernando , Craig, Fiona E. , Simons, Jeffrey S. , Viswanathan, Pushpa, Yilmaz, S. , Monaco, Sara E. , Monaco, S E , Pantanowitz, Liron , Picarsic, Jennifer , Simons, J. P.

Mayo Clinic

Cytopathology | March 26, 2018 | Volume: 29 | Issue: 3 | Pages: 241-246

10.1111/cyt.12529 | PMID 29577488 Get It

IntroductionEctopic thymic tissue can arise as an asymptomatic neck mass, which may be detected on imaging studies. The aim of this study was to determine the incidence of ectopic thymic tissue in paediatric FNAs and to the correlate clinical, radiological and cytomorphological findings.MethodsFNAs in children with neck and mediastinal lesions performed between January 2012 and July 2016 were reviewed for cases of ectopic thymus. These were then evaluated and correlated with the cytology findings.ResultsOf 739 FNAs, 13 (1.8%) cases from 11 patients showed ectopic thymic tissue. The targeted lesions were in the thyroid (n = 7), submandibular region (n = 1), superior mediastinum (n = 1) and paratracheal region (n = 1). The most common indication was for microcalcifications concerning for papillary thyroid carcinoma on ultrasound (n = 6). Imaging findings included fusiform lesions with linear and punctuate bright echoes. The cytology evaluation showed small lymphocytes with discohesive epithelioid cells in most cases, and proteinaceous fluid in the cystic case. There were rare macrophages and Hassall's corpuscles. Flow cytometry and/or immunostains were performed in all cases, supporting thymic origin.ConclusionEctopic thymic tissue is rarely present as a neck mass or thyroid nodule on FNA biopsy. The ultrasound imaging findings reveal a well‐defined fusiform lesion with punctate bright echoes that could be misinterpreted as papillary thyroid carcinoma. The aspirates show a small lymphoid population, immunophenotypically compatible with thymic T‐cells, in addition to scattered epithelial cells. Therefore, knowledge of the typical ultrasonographic and cytopathological features can help make a definitive diagnosis and avoid more invasive procedures in paediatric patients.
Genetic variants in CETP increase risk of intracerebral hemorrhage
Anderson, Christopher D. , Falcone, Guido J. , Phuah, Chia‐Ling , Radmanesh, Farid , Brouwers, H. Bart , Battey, Thomas W.K., Biffi, Alessandro , Liu, Dajiang J. , Viswanathan, Anand , Greenberg, Steven M. , Brown, Devin L. , Worrall, Bradford B. , Silliman, Scott, Tirschwell, David , Flaherty, Matthew L. , Kraft, Peter , Jagiełła, Jeremiasz , Schmidt, Helena , Hansen, Björn M. , Jiménez-Conde, Jordi , Giralt‐Steinhauer, Eva , Elosúa, Roberto , Cuadrado‐Godia, Elisa , Soriano‐Tárraga, Carolina , Nieuwenhuizen, Koen M. van , Klijn, Catharina J.M. , Rannikmäe, Kristiina , Samarasekera, Neshika , Salman, Rustam Al‐Shahi , Sudlow, Catherine L., Deary, Ian J. , Morotti, Andrea , Pezzini, Alessandro , Pera, Joanna , Urbanik, Andrzej, Pichler, Alexander , Montaner, Joan , Fernández‐Cadenas, Israel , Delgado, Pilar , Słowik, Agnieszka , Schmidt, Reinhold, Kidwell, Chelsea S., Kittner, Steven J. , Waddy, Salina P., Langefeld, Carl D. , Kathiresan, Sekar , Woo, Daniel , Sudlow, Cathie , Lee, Chaeyoung , Meschia, James F , van Nieuwenhuizen, Koen M , Peloso, Gina M. , Ayres, Alison M. , Goldstein, Joshua Norkin , Selim, Magdy H. , Meschia, James F. , Enzinger, Christian , Norrving, Bo , Roquer, Jaume , Lindgren, Arne G. , Abecasis, Gonçalo R. , Willer, Cristen J , Rosand, Jonathan M. , Kraft, Peter , Montaner, Joan , Pezzini, Alessandro , Al-Shahi Salman, Rustam

Mayo Clinic

Annals of Neurology | September 22, 2016 | Volume: 80 | Issue: 5 | Pages: 730-740

10.1002/ana.24780 | PMID 27717122 Get It

ObjectiveIn observational epidemiologic studies, higher plasma high‐density lipoprotein cholesterol (HDL‐C) has been associated with increased risk of intracerebral hemorrhage (ICH). DNA sequence variants that decrease cholesteryl ester transfer protein (CETP) gene activity increase plasma HDL‐C; as such, medicines that inhibit CETP and raise HDL‐C are in clinical development. Here, we test the hypothesis that CETP DNA sequence variants associated with higher HDL‐C also increase risk for ICH.MethodsWe performed 2 candidate‐gene analyses of CETP. First, we tested individual CETP variants in a discovery cohort of 1,149 ICH cases and 1,238 controls from 3 studies, followed by replication in 1,625 cases and 1,845 controls from 5 studies. Second, we constructed a genetic risk score comprised of 7 independent variants at the CETP locus and tested this score for association with HDL‐C as well as ICH risk.ResultsTwelve variants within CETP demonstrated nominal association with ICH, with the strongest association at the rs173539 locus (odds ratio [OR] = 1.25, standard error [SE] = 0.06, p = 6.0 × 10−4) with no heterogeneity across studies (I2 = 0%). This association was replicated in patients of European ancestry (p = 0.03). A genetic score of CETP variants found to increase HDL‐C by ∼2.85mg/dl in the Global Lipids Genetics Consortium was strongly associated with ICH risk (OR = 1.86, SE = 0.13, p = 1.39 × 10−6).InterpretationGenetic variants in CETP associated with increased HDL‐C raise the risk of ICH. Given ongoing therapeutic development in CETP inhibition and other HDL‐raising strategies, further exploration of potential adverse cerebrovascular outcomes may be warranted. Ann Neurol 2016;80:730–740
A Phase I Trial of Vorinostat and Alvocidib in Patients with Relapsed, Refractory, or Poor Prognosis Acute Leukemia, or Refractory Anemia with Excess Blasts-2
Holkova, Beata , Supko, Jeffrey G. , Ames, Matthew M. , Shapiro, Geoffrey I. , Perkins, Edward Brent, Ramakrishnan, Viswanathan , Tombes, Mary Beth, Honeycutt, Connie, McGovern, Renee M., Shrader, Ellen, Wellons, Martha D., Sankala, Heidi, Doyle, Austin, Wright, John, Roberts, John D. , Reid, Joel M. , Kmieciak, Maciej , Wright, John, Grant, Steven , Shapiro, Geoffrey I

Mayo Clinic

Clinical Cancer Research | March 20, 2013 | Volume: 19 | Issue: 7 | Pages: 1873-1883

10.1158/1078-0432.ccr-12-2926 | PMID 23515411 Get It

Abstract Purpose: This phase I study was conducted to identify the maximum-tolerated dose (MTD) of alvocidib when combined with vorinostat in patients with relapsed, refractory, or poor prognosis acute leukemia, or refractory anemia with excess blasts-2. Secondary objectives included investigating the pharmacokinetic and pharmacodynamic effects of the combination. Experimental Design: Patients received vorinostat (200 mg orally, three times a day, for 14 days) on a 21-day cycle, combined with 2 different alvocidib administration schedules: a 1-hour intravenous infusion, daily × 5; or a 30-minute loading infusion followed by a 4-hour maintenance infusion, weekly × 2. The alvocidib dose was escalated using a standard 3+3 design. Results: Twenty-eight patients were enrolled and treated. The alvocidib MTD was 20 mg/m2 (30-minute loading infusion) followed by 20 mg/m2 (4-hour maintenance infusion) on days one and eight, in combination with vorinostat. The most frequently encountered toxicities were cytopenias, fatigue, hyperglycemia, hypokalemia, hypophosphatemia, and QT prolongation. Dose-limiting toxicities (DLT) were cardiac arrhythmia-atrial fibrillation and QT prolongation. No objective responses were achieved although 13 of 26 evaluable patients exhibited stable disease. Alvocidib seemed to alter vorinostat pharmacokinetics, whereas alvocidib pharmacokinetics were unaffected by vorinostat. Ex vivo exposure of leukemia cells to plasma obtained from patients after alvocidib treatment blocked vorinostat-mediated p21CIP1 induction and downregulated Mcl-1 and p-RNA Pol II for some specimens, although parallel in vivo bone marrow responses were infrequent. Conclusions: Alvocidib combined with vorinostat is well tolerated. Although disease stabilization occurred in some heavily pretreated patients, objective responses were not obtained with these schedules. Clin Cancer Res; 19(7); 1873–83. ©2013 AACR.
Effects of 11β-hydroxysteroid dehydrogenase-1 inhibition on hepatic glycogenolysis and gluconeogenesis
Winnick, Jason J. , Ramnanan, Christopher J. , Saraswathi, Viswanathan , Roop, Joshua, Jacobson, Peer B., Jung, Paul , Basu, Rita , Cherrington, Alan D. , Scott, M. , Edgerton, Dale S.

Mayo Clinic

American Journal of Physiology-Endocrinology and Metabolism | February 13, 2013 | Volume: 304 | Issue: 7 | Pages: E747-E756

10.1152/ajpendo.00639.2012 | PMID 23403942 Get It

The aim of this study was to determine the effect of prolonged 11β-hydroxysteroid dehydrogenase-1 (11β-HSD1) inhibition on basal and hormone-stimulated glucose metabolism in fasted conscious dogs. For 7 days prior to study, either an 11β-HSD1 inhibitor (HSD1-I; n = 6) or placebo (PBO; n = 6) was administered. After the basal period, a 4-h metabolic challenge followed, where glucagon (3×-basal), epinephrine (5×-basal), and insulin (2×-basal) concentrations were increased. Hepatic glucose fluxes did not differ between groups during the basal period. In response to the metabolic challenge, hepatic glucose production was stimulated in PBO, resulting in hyperglycemia such that exogenous glucose was required in HSD-I ( P < 0.05) to match the glycemia between groups. Net hepatic glucose output and endogenous glucose production were decreased by 11β-HSD1 inhibition ( P < 0.05) due to a reduction in net hepatic glycogenolysis ( P < 0.05), with no effect on gluconeogenic flux compared with PBO. In addition, glucose utilization ( P < 0.05) and the suppression of lipolysis were increased ( P < 0.05) in HSD-I compared with PBO. These data suggest that inhibition of 11β-HSD1 may be of therapeutic value in the treatment of diseases characterized by insulin resistance and excessive hepatic glucose production.
Vascular risk factors and dementia
Viswanathan, Anand , Rocca, Walter A. , Tzourio, Christophe , Tzourio, Christophe

Mayo Clinic

Neurology | January 26, 2009 | Volume: 72 | Issue: 4 | Pages: 368-374

10.1212/01.wnl.0000341271.90478.8e | PMID 19171835 Get It

Mutation in Glycerol-3-Phosphate Dehydrogenase 1–Like Gene ( GPD1-L ) Decreases Cardiac Na + Current and Causes Inherited Arrhythmias
London, Barry , Michalec, Michael, Mehdi, Haider , Zhu, Xiaodong , Kerchner, Laurie J. , Sanyal, Shamarendra, Viswanathan, Prakash C., Pfahnl, Arnold , Shang, Lijuan L., Madhusudanan, Mohan, Baty, Catherine J. , Lagana, Stephen M. , Gutmann, Rebecca, Ackerman, Michael J. , McNamara, Dennis M. , Dudley, Samuel C. , Aleong, Ryan G. , Weiss, Raul , London, Barry

Mayo Clinic

Circulation | October 29, 2007 | Volume: 116 | Issue: 20 | Pages: 2260-2268

10.1161/circulationaha.107.703330 | PMID 17967977 Get It

Background— Brugada syndrome is a rare, autosomal-dominant, male-predominant form of idiopathic ventricular fibrillation characterized by a right bundle-branch block and ST elevation in the right precordial leads of the surface ECG. Mutations in the cardiac Na + channel SCN5A on chromosome 3p21 cause ≈20% of the cases of Brugada syndrome; most mutations decrease inward Na + current, some by preventing trafficking of the channels to the surface membrane. We previously used positional cloning to identify a new locus on chromosome 3p24 in a large family with Brugada syndrome and excluded SCN5A as a candidate gene. Methods and Results— We used direct sequencing to identify a mutation (A280V) in a conserved amino acid of the glycerol-3-phosphate dehydrogenase 1–like ( GPD1-L ) gene. The mutation was present in all affected individuals and absent in >500 control subjects. GPD1-L RNA and protein are abundant in the heart. Compared with wild-type GPD1-L, coexpression of A280V GPD1-L with SCN5A in HEK cells reduced inward Na + currents by ≈50% ( P <0.005). Wild-type GPD1-L localized near the cell surface to a greater extent than A280V GPD1-L. Coexpression of A280V GPD1-L with SCN5A reduced SCN5A cell surface expression by 31±5% ( P =0.01). Conclusions— GPD1-L is a novel gene that may affect trafficking of the cardiac Na + channel to the cell surface. A GPD1-L mutation decreases SCN5A surface membrane expression, reduces inward Na + current, and causes Brugada syndrome.
EGFR-T790M Is a Rare Lung Cancer Susceptibility Allele with Enhanced Kinase Activity
Vikis, Haris G., Sato, Mitsuo , James, Michael A. , Wang, Daolong, Wang, Yian , Wang, Min , Jia, Dongmei , Liu, Yan , Bailey‐Wilson, Joan E. , Pinney, Susan M. , Petersen, Gloria M. , Wiest, Jonathan S., Fain, Pamela R., Schwartz, Ann G. , Gazdar, Adi F. , Gaba, Colette , Rothschild, Henry, Mandal, Diptasri , Kupert, Elena, Seminara, Daniela, Viswanathan, Avinash, Govindan, Ramaswamy , Anderson, Marshall W., You, Ming , Amos, Christopher I. , Andrade, Mariza de , Yang, Ping , Minna, John Dorrance , Wilson, Richard K , Pinney, Susan M , Govindan, Ramaswamy

Mayo Clinic

Cancer Research | May 18, 2007 | Volume: 67 | Issue: 10 | Pages: 4665-4670

10.1158/0008-5472.can-07-0217 | PMID 17510392 Get It

Abstract The use of tyrosine kinase inhibitors (TKI) has yielded great success in treatment of lung adenocarcinomas. However, patients who develop resistance to TKI treatment often acquire a somatic resistance mutation (T790M) located in the catalytic cleft of the epidermal growth factor receptor (EGFR) enzyme. Recently, a report describing EGFR-T790M as a germ-line mutation suggested that this mutation may be associated with inherited susceptibility to lung cancer. Contrary to previous reports, our analysis indicates that the T790M mutation confers increased Y992 and Y1068 phosphorylation levels. In a human bronchial epithelial cell line, overexpression of EGFR-T790M displayed a growth advantage over wild-type (WT) EGFR. We also screened 237 lung cancer family probands, in addition to 45 bronchoalveolar tumors, and found that none of them contained the EGFR-T790M mutation. Our observations show that EGFR-T790M provides a proliferative advantage with respect to WT EGFR and suggest that the enhanced kinase activity of this mutant is the basis for rare cases of inherited susceptibility to lung cancer. [Cancer Res 2007;67(10):4665–70]
Identification of a Novel Tumor Suppressor Gene p34 on Human Chromosome 6q25.1
Vikis, Haris G., Wang, Yian , Jia, Dongmei , Wang, Daolong, Bailey‐Wilson, Joan E. , Pinney, Susan M. , Petersen, Gloria M. , Wiest, Jonathan S., Fain, Pamela R., Schwartz, Ann G. , Gazdar, Adi F., Gaba, Colette , Rothschild, Henry, Mandal, Diptasri , Kupert, Elena, Seminara, Daniela, Liu, Yan , Viswanathan, Avinash, Govindan, Ramaswamy , Anderson, Marshall W., You, Ming , Wang, Min , Bierut, Laura Jean , Amos, Christopher I. , Andrade, Mariza de , Yang, Ping , Gazdar, Adi, Minna, John Dorrance , Wilson, Richard K , Pinney, Susan M , Govindan, Ramaswamy

Mayo Clinic

Cancer Research | January 8, 2007 | Volume: 67 | Issue: 1 | Pages: 93-99

10.1158/0008-5472.can-06-2723 | PMID 17210687 Get It

Abstract In this study, we observed loss of heterozygosity (LOH) in human chromosomal fragment 6q25.1 in sporadic lung cancer patients. LOH was observed in 65% of the 26 lung tumors examined and was narrowed down to a 2.2-Mb region. Single-nucleotide polymorphism (SNP) analysis of genes located within this region identified a candidate gene, termed p34. This gene, also designated as ZC3H12D, C6orf95, FLJ46041, or dJ281H8.1, carries an A/G nonsynonymous SNP at codon 106, which alters the amino acid from lysine to arginine. Nearly 73% of heterozygous lung cancer tissues with LOH and the A/G SNP also exhibited loss of the A allele. In vitro clonogenic and in vivo nude mouse studies showed that overexpression of the A allele exerts tumor suppressor function compared with the G allele. p34 is located within a recently mapped human lung cancer susceptibility locus, and association of the p34 A/G SNP was tested among these families. No significant association between the less frequent G allele and lung cancer susceptibility was found. Our results suggest that p34 may be a novel tumor suppressor gene involved in sporadic lung cancer but it seems not to be the candidate familial lung cancer susceptibility gene linked to chromosomal region 6q23-25. [Cancer Res 2007;67(1):93–9]