26 results on '"Duvvuru S"'
Search Results
2. High-throughput behavioral phenotyping in the expanded panel of BXD recombinant inbred strains
- Author
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Philip, V. M., Duvvuru, S., Gomero, B., Ansah, T. A., Blaha, C. D., Cook, M. N., Hamre, K. M., Lariviere, W. R., Matthews, D. B., Mittleman, G., Goldowitz, D., and Chesler, E. J.
- Published
- 2010
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3. BEHAVIORAL ANALYSIS OF THE GENETIC MODULATION OF DEPRESSION AND ATAXIA USING AN EXTENDED PANEL OF BXD RECOMBINANT INBRED MOUSE LINES: 005
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Hamre, K. M., Du, X. P., Kincaide, K., Donohue, K., OʼHara, B., Philip, V., Duvvuru, S., Chesler, E., and Goldowitz, D.
- Published
- 2008
4. The PNPLA3 I148M variant is associated with transaminase elevations in type 2 diabetes patients treated with basal insulin peglispro
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Pillai, S, primary, Duvvuru, S, additional, Bhatnagar, P, additional, Foster, W, additional, Farmen, M, additional, Shankar, S, additional, Harris, C, additional, Bastyr, E, additional, Hoogwerf, B, additional, and Haupt, A, additional
- Published
- 2017
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5. A compile-time memory-reuse scheme for concurrent logic programs
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Duvvuru, S., primary, Sundararajan, R., additional, Tick, E., additional, Sastry, A. V. S., additional, Hansen, L., additional, and Zhong, X., additional
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6. The PNPLA3 I148M variant is associated with transaminase elevations in type 2 diabetes patients treated with basal insulin peglispro
- Author
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Pillai, S, Duvvuru, S, Bhatnagar, P, Foster, W, Farmen, M, Shankar, S, Harris, C, Bastyr, E, Hoogwerf, B, and Haupt, A
- Abstract
Basal insulin peglispro (BIL) is a novel insulin with hepato-preferential action. In phase 3 trials, BIL showed significantly improved glycemic control but higher levels of transaminases (alanine aminotransferase (ALT) and aspartate aminotransferase (AST)), triglycerides (TGs) and liver fat content (LFC) compared with insulin glargine (GL). As variants in PNPLA3 (I148M) and TM6SF2 (E167K) are associated with nonalcoholic fatty liver disease, we assessed these variants in type 2 diabetes (T2D) patients randomized to receive BIL (n=1822) or GL (n=1270) in three phase 3 trials. Magnetic resonance imaging assessments of LFC were conducted in a subset of patients (n=296). Analyses showed α-corrected significant increases in change from baseline in AST (P=0.0004) and nominal increases in ALT (P=0.019), and LFC (P=0.035) for PNPLA3 (148M/M) genotypes in the BIL arm at 26 weeks but no significant associations in GL. PNPLA3 (148M/M) was also associated with increases in total cholesterol (P=0.014) and low-density lipoprotein cholesterol (P=0.005) but not with hemoglobin A1c or TG. T2D patients with the PNPLA3 (148M/M) genotype treated with BIL may be more susceptible to increased liver fat deposition. The current data provide further insights into the biological role of PNPLA3 in lipid metabolism.
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- 2018
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7. Perceptual gender identity of voices in pre-pubertal children.
- Author
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Duvvuru S and Sreedevi N
- Abstract
The present study investigated sexual dimorphism in voices of children. Ten children each in the age group of 4-5 years and 5-6 years participated in the study. Listener's identification of gender in phonation and speech tasks were obtained. Results revealed that gender identification was better in the older age group, and in speech compared to phonation. The results are discussed with reference to perceptual cues taken by the listeners to identify the gender of the preadolescents. [ABSTRACT FROM AUTHOR]
- Published
- 2009
8. Evaluation of a branch target address cache
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Duvvuru, S., primary and Arya, S., additional
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9. An architecture for high instruction level parallelism
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Arya, S., primary, Sachs, H., additional, and Duvvuru, S., additional
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10. An architecture for high instruction level parallelism.
- Author
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Arya, S., Sachs, H., and Duvvuru, S.
- Published
- 1995
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11. Evaluation of a branch target address cache.
- Author
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Duvvuru, S. and Arya, S.
- Published
- 1995
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12. A Microbe Associated with Sleep Revealed by a Novel Systems Genetic Analysis of the Microbiome in Collaborative Cross Mice.
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Bubier JA, Philip VM, Quince C, Campbell J, Zhou Y, Vishnivetskaya T, Duvvuru S, Blair RH, Ndukum J, Donohue KD, Foster CM, Mellert DJ, Weinstock G, Culiat CT, O'Hara BF, Palumbo AV, Podar M, and Chesler EJ
- Subjects
- Animals, Anti-Bacterial Agents pharmacology, Bacteroides genetics, Chromosomes, Human, Pair 7 genetics, Gastrointestinal Microbiome genetics, Genomics, Genotype, Humans, Mice, Obesity microbiology, Obesity physiopathology, GTPase-Activating Proteins genetics, Guanine Nucleotide Exchange Factors genetics, Obesity genetics, Receptors, Leptin genetics, Sleep genetics
- Abstract
The microbiome influences health and disease through complex networks of host genetics, genomics, microbes, and environment. Identifying the mechanisms of these interactions has remained challenging. Systems genetics in laboratory mice ( Mus musculus ) enables data-driven discovery of biological network components and mechanisms of host-microbial interactions underlying disease phenotypes. To examine the interplay among the whole host genome, transcriptome, and microbiome, we mapped QTL and correlated the abundance of cecal messenger RNA, luminal microflora, physiology, and behavior in a highly diverse Collaborative Cross breeding population. One such relationship, regulated by a variant on chromosome 7, was the association of Odoribacter (Bacteroidales) abundance and sleep phenotypes. In a test of this association in the BKS.Cg- Dock7
m +/+ Leprdb / J mouse model of obesity and diabetes, known to have abnormal sleep and colonization by Odoribacter , treatment with antibiotics altered sleep in a genotype-dependent fashion. The many other relationships extracted from this study can be used to interrogate other diseases, microbes, and mechanisms., (Copyright © 2020 Bubier et al.)- Published
- 2020
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13. Coding variants in PNPLA3 and TM6SF2 are risk factors for hepatic steatosis and elevated serum alanine aminotransferases caused by a glucagon receptor antagonist.
- Author
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Guzman CB, Duvvuru S, Akkari A, Bhatnagar P, Battioui C, Foster W, Zhang XM, Shankar SS, Deeg MA, Chalasani N, Hardy TA, Kazda CM, and Pillai SG
- Abstract
LY2409021 is a glucagon receptor antagonist that was associated with hepatic steatosis and elevated aminotransferases in phase 2 diabetes studies. We investigated the relationship between selected genetic variants and hepatic steatosis and elevated alanine aminotransferases (ALTs) associated with LY2409021. Patients participated in a 6-week placebo-controlled trial (I1R-MC-GLDI [GLDI], n = 246) and a 52-week placebo- and active comparator-controlled trial (I1R-MC-GLDJ [GLDJ], n = 158). GLDJ had endpoints at 6 months, including measures of hepatic fat fraction (HFF) by magnetic resonance imaging. The five genes tested were patatin-like phospholipase domain containing 3 ( PNPLA3 ) (rs738409 and rs738491), transmembrane 6 superfamily member 2 ( TM6SF2 ) (rs58542926), peroxisome proliferative activated receptor gamma coactivator 1 alpha ( PPARGC1A ) (rs4361373, rs3774921, rs2970849), adenylate cyclase 3 ( ADCY3 ) ( rs713586), and insulin-like growth factor 1 ( IGF-1 ) (rs1520220). In GLDI, PNPLA3 I148M ( P = 0.001) and TM6SF2 E167K ( P = 0.001) were significantly associated with an increase in ALT at 6 weeks for LY2409021 but not for placebo. In GLDJ, PNPLA3 I148M showed the same effect ( P = 0.007) on ALT at 6 months but the placebo or sitagliptin did not. In GLDJ, both PNPLA3 and TM6SF2 risk-allele carriers showed increases in HFF that were numerically greater but not statistically significant. The carriers of PNPLA3 and/or TM6SF2 risk alleles showed significantly increased ALT (GLDI, +13.28 U/L in carriers versus +4.84 U/L in noncarriers, P = 4 × 10
-5 ; GLDJ, +14.6 U/L in carriers versus +1.7 in noncarriers, P = 0.0018) and HFF (GLDJ, +5.35% in carriers versus 2.38% in noncarriers, P = 0.048). Elevation of transaminase and HFF were also noted in the noncarriers but at a significantly lower degree. Conclusion: The carriers of PNPLA3 and/or TM6SF2 variant alleles are at risk for hepatic steatosis and elevated ALT levels caused by LY2409021, a glucagon receptor antagonist. More studies are needed to investigate if our observations are generalizable to hepatic steatosis caused by other medications. ( Hepatology Communications 2018;2:561-570).- Published
- 2018
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14. The Effect of Timbre, Pitch, and Vibrato on Vocal Pitch-Matching Accuracy.
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Duvvuru S and Erickson M
- Subjects
- Acoustics, Adult, Biomechanical Phenomena, Female, Humans, Middle Aged, Speech Production Measurement, Tennessee, Vibration, Young Adult, Imitative Behavior, Phonation, Pitch Perception, Singing, Vocal Cords physiology, Voice Quality
- Abstract
Objective/hypothesis: This study seeks to examine how target stimulus timbre, vibrato, pitch, and singer classification affect pitch-matching accuracy., Study Design: This is a repeated-measures factorial design., Methods: Source signals were synthesized with a source slope of -12 dB/octave with and without vibrato at each of the pitches, C4, B4, and F5. These source signals were filtered using five formant patterns (A-E) constituting a total of 30 stimuli (5 formant patterns × 3 pitches × 2 vibrato conditions). Twelve sopranos and 11 mezzo-sopranos with at least 3 years of individual voice training were recruited from the University Of Tennessee, Knoxville, School of Music and the Knoxville Opera Company. Each singer attempted to match the pitch of all 30 stimuli presented twice in a random order., Results: Results indicated that there was no significant effect of formant pattern on pitch-matching accuracy. With increasing pitch from C4 to F5, pitch-matching accuracy increased in midpoint of the vowel condition but not in prephonatory set condition. Mezzo-sopranos moved toward being in tune from prephonatory to midpoint of the vowel. However, sopranos at C4 sang closer to being in tune at prephonatory but lowered the pitch at the midpoint of the vowel. Presence or absence of vibrato did not affect the pitch-matching accuracy. However, the interesting finding of the study was that singers attempted to match the timbre of stimuli with vibrato., Conclusions: The results of this study show that pitch matching is a complex process affected by many parameters., (Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)
- Published
- 2016
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15. PON1 Q192R genetic variant and response to clopidogrel and prasugrel: pharmacokinetics, pharmacodynamics, and a meta-analysis of clinical outcomes.
- Author
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Mega JL, Close SL, Wiviott SD, Man M, Duvvuru S, Walker JR, Sundseth SS, Collet JP, Delaney JT, Hulot JS, Murphy SA, Paré G, Price MJ, Sibbing D, Simon T, Trenk D, Antman EM, and Sabatine MS
- Subjects
- Aged, Amino Acid Substitution, Aryldialkylphosphatase metabolism, Clopidogrel, Female, Humans, Male, Middle Aged, Percutaneous Coronary Intervention, Randomized Controlled Trials as Topic, Ticlopidine administration & dosage, Ticlopidine pharmacokinetics, Acute Coronary Syndrome metabolism, Acute Coronary Syndrome therapy, Aryldialkylphosphatase genetics, Mutation, Missense, Prasugrel Hydrochloride administration & dosage, Prasugrel Hydrochloride pharmacokinetics, Ticlopidine analogs & derivatives
- Abstract
Clopidogrel and prasugrel are antiplatelet therapies commonly used to treat patients with cardiovascular disease. They are both pro-drugs requiring biotransformation into active metabolites. It has been proposed that a genetic variant Q192R (rs662 A>G) in PON1 significantly alters the biotransformation of clopidogrel and affects clinical outcomes; however, this assertion has limited support. The relationship between this variant and clinical outcomes with prasugrel has not been studied. We genotyped PON1 Q192R in 275 healthy subjects treated with clopidogrel or prasugrel and 2922 patients with an ACS undergoing PCI randomized to treatment with clopidogrel or prasugrel in the TRITON-TIMI 38 trial. A meta-analysis was performed including 13 studies and 16,760 clopidogrel-treated patients. Among clopidogrel-treated subjects, there were no associations between Q192R and active drug metabolite levels (P = 0.62) or change in platelet aggregation (P = 0.51). Consistent with these results, in clopidogrel-treated patients in TRITON-TIMI 38, there was no association between Q192R and the rates of CV death, myocardial infarction, or stroke (RR 11.2 %, QR 8.6 %, and QQ 9.3 %; P = 0.66) or stent thrombosis (RR 2.4 %, QR 0.7 %, and QQ 1.6 %, P = 0.30), with patients with the putative at-risk Q variant having numerically lower event rates. Likewise, among prasugrel-treated subjects, there were no associations between Q192R and active drug metabolite levels (P = 0.88), change in platelet aggregation (P = 0.97), or clinical outcomes (P = 0.72). In a meta-analysis, the Q variant was not significantly associated with MACE (QQ vs. RR 1.22, 95 % CI 0.84-1.76) or stent thrombosis (QQ vs. RR OR 1.36, 95 % CI 0.77-2.38). Furthermore, when restricted to the validation studies, the OR (95 % CI) for MACE and stent thrombosis were 0.99 (0.77-1.27) and 1.23 (0.74-2.03), respectively. In the present study, the Q192R genetic variant in PON1 was not associated with the pharmacologic or clinical response to clopidogrel, nor was it associated with the response to prasugrel. The meta-analysis reinforced a lack of a significant association between Q192R and cardiovascular outcomes in clopidogrel-treated patients.
- Published
- 2016
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16. Impact of CYP2C19 Metabolizer Status on Patients With ACS Treated With Prasugrel Versus Clopidogrel.
- Author
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Doll JA, Neely ML, Roe MT, Armstrong PW, White HD, Prabhakaran D, Winters KJ, Duvvuru S, Sundseth SS, Jakubowski JA, Gurbel PA, Bhatt DL, Ohman EM, and Fox KAA
- Subjects
- Acute Coronary Syndrome blood, Acute Coronary Syndrome genetics, Aged, Alleles, Clopidogrel, Cytochrome P-450 CYP2C19 metabolism, Dose-Response Relationship, Drug, Double-Blind Method, Female, Follow-Up Studies, Genotype, Humans, Male, Middle Aged, Platelet Aggregation Inhibitors administration & dosage, Platelet Function Tests, Purinergic P2Y Receptor Antagonists administration & dosage, Retrospective Studies, Ticlopidine administration & dosage, Treatment Outcome, Acute Coronary Syndrome drug therapy, Cytochrome P-450 CYP2C19 genetics, DNA genetics, Polymorphism, Genetic, Prasugrel Hydrochloride administration & dosage, Ticlopidine analogs & derivatives
- Abstract
Background: Certain alleles of the CYP2C19 gene are associated with higher platelet reactivity and increased ischemic events among patients treated with clopidogrel. However, the relationship of CYP2C19 genotype and outcomes in medically managed patients with acute coronary syndromes (ACS) is not known., Objectives: This study sought to assess the effect of CYP2C19 genotype on ischemic outcomes in patients with ACS initially managed medically without revascularization who were randomized to either clopidogrel or prasugrel., Methods: We classified patients as extensive metabolizers (EM) or reduced metabolizers (RM) based on CYP2C19 genotype and evaluated ischemic outcomes and platelet reactivity. Among 9,326 patients enrolled from 2008 to 2011, 5,736 participated in the genetics cohort; of these, 2,236 had platelet function testing data., Results: There was no association between CYP2C19 metabolizer status (EM vs. RM) and the primary composite endpoint of cardiovascular death, myocardial infarction (MI), or stroke (hazard ratio [HR]: 0.86). EM and RM patients had similar rates of the primary endpoint whether treated with prasugrel (HR: 0.82) or clopidogrel (HR: 0.91; p for interaction = 0.495). After adjusting for clinical and treatment variables, EM patients had a lower risk of MI versus RM patients (HR: 0.80), but risks of other outcomes were similar. RM patients had significantly higher mean P2Y12 reaction units versus EM patients when treated with clopidogrel (39.93), but not with prasugrel (3.87)., Conclusions: CYP2C19 metabolizer status is not associated with the composite outcome of cardiovascular death, MI, or stroke in medically managed ACS patients treated with clopidogrel or prasugrel. Our findings do not support routine CYP2C19 genetic testing in this population. (A Comparison of Prasugrel and Clopidogrel in Acute Coronary Syndrome Subjects [TRILOGY ACS]; NCT00699998)., (Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)
- Published
- 2016
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17. The effect of CYP2C19 gene polymorphisms on the pharmacokinetics and pharmacodynamics of prasugrel 5-mg, prasugrel 10-mg and clopidogrel 75-mg in patients with coronary artery disease.
- Author
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Gurbel PA, Bergmeijer TO, Tantry US, ten Berg JM, Angiolillo DJ, James S, Lindahl TL, Svensson P, Jakubowski JA, Brown PB, Duvvuru S, Sundseth S, Walker JR, Small D, Moser BA, Winters KJ, and Erlinge D
- Subjects
- Aged, Clinical Protocols, Clopidogrel, Coronary Artery Disease genetics, Female, Genotype, Humans, Male, Middle Aged, Phenotype, Piperazines administration & dosage, Platelet Aggregation drug effects, Platelet Aggregation genetics, Platelet Aggregation Inhibitors administration & dosage, Polymorphism, Genetic, Prasugrel Hydrochloride, Thiophenes administration & dosage, Ticlopidine administration & dosage, Ticlopidine pharmacokinetics, Treatment Outcome, Coronary Artery Disease drug therapy, Cytochrome P-450 CYP2C19 genetics, Piperazines pharmacokinetics, Platelet Aggregation Inhibitors pharmacokinetics, Thiophenes pharmacokinetics, Ticlopidine analogs & derivatives
- Abstract
CYP2C19 genotype has been shown to impact response to clopidogrel 75-mg but not prasugrel 10-mg. Here, we assessed effects of CYP2C19 metaboliser status on pharmacokinetics (PK) and pharmacodynamic (PD) responses to prasugrel 5-mg and 10-mg and clopidogrel 75-mg using data from two PK/PD studies in stable coronary artery disease (CAD) patients (GENERATIONS and FEATHER). Active metabolite concentrations (area under the curve, AUC[0-tlast]), maximum platelet aggregation (MPA) measured by light transmission aggregometry, vasodilator-stimulated phosphoprotein platelet reactivity index, and VerifyNow P2Y12-platelet reaction units (VN-PRU) were analysed by CYP2C19-predicted phenotype (extensive metaboliser [EM; N=154], *2-*8 non-carriers, vs reduced metaboliser [RM; N=41],*2-*8 carriers/*17 non-carriers). AUC(0-tlast) was unaffected by metaboliser status for prasugrel 5-mg and 10-mg (geometric mean EM/RM ratios 1.00, 95% confidence interval [CI]: 0.86,1.17, p>0.99; and 0.97, 95% CI:0.85,1.12, p=0.71, respectively), but was lower among RMs receiving clopidogrel 75-mg (1.37, 95% CI:1.14,1.65, p<0.001). Platelet reactivity was not significantly affected by CYP2C19 metaboliser status for prasugrel 5-mg, or for prasugrel 10-mg by MPA and VN-PRU, but for clopidogrel 75-mg was significantly higher in reduced metabolisers (all measures p<0.01). Prasugrel 10-mg showed greater antiplatelet effects vs clopidogrel 75-mg (all comparisons p<0.001). Prasugrel 5-mg showed greater antiplatelet effects vs clopidogrel 75-mg in RMs (all p<0.001), and comparable effects in EMs (all p≥0.37). In contrast to clopidogrel, prasugrel active metabolite PK was not influenced by CYP2C19 genotype. Antiplatelet effect for prasugrel 10-mg was greater irrespective of metaboliser status and for prasugrel 5-mg was greater for RMs and comparable for EMs as compared to clopidogrel 75-mg.
- Published
- 2014
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18. Transferring from clopidogrel loading dose to prasugrel loading dose in acute coronary syndrome patients. High on-treatment platelet reactivity analysis of the TRIPLET trial.
- Author
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Diodati JG, Saucedo JF, Cardillo TE, Jakubowski JA, Henneges C, Effron MB, Lipkin FR, Walker JR, Duvvuru S, Sundseth SS, Fisher HN, and Angiolillo DJ
- Subjects
- Acute Coronary Syndrome blood, Acute Coronary Syndrome diagnosis, Aged, Blood Platelets metabolism, Clopidogrel, Cytochrome P-450 CYP2C19 genetics, Cytochrome P-450 CYP2C19 metabolism, Double-Blind Method, Drug Administration Schedule, Drug Resistance, Female, Genotype, Humans, Male, Middle Aged, Phenotype, Piperazines adverse effects, Piperazines metabolism, Platelet Aggregation Inhibitors adverse effects, Platelet Aggregation Inhibitors metabolism, Platelet Function Tests, Prasugrel Hydrochloride, Thiophenes adverse effects, Thiophenes metabolism, Ticlopidine administration & dosage, Ticlopidine adverse effects, Ticlopidine metabolism, Time Factors, Treatment Outcome, Acute Coronary Syndrome therapy, Blood Platelets drug effects, Drug Substitution, Percutaneous Coronary Intervention adverse effects, Piperazines administration & dosage, Platelet Aggregation Inhibitors administration & dosage, Thiophenes administration & dosage, Ticlopidine analogs & derivatives
- Abstract
High on-treatment platelet reactivity (HPR) has been identified as an independent risk factor for ischaemic events. The randomised, double-blind, TRIPLET trial included a pre-defined comparison of HPR in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI) following a placebo/600-mg clopidogrel loading dose (LD) immediately before a subsequent prasugrel 60-mg or 30-mg LD. Platelet reactivity was assessed using the VerifyNow® P2Y12 assay (P2Y12 Reaction Units, PRU) within 24 hours (h) following the placebo/clopidogrel LD (immediately prior to prasugrel LD), and at 2, 6, 24, 72 h following prasugrel LDs. The impact of CYP2C19 predicted metaboliser phenotype (extensive metabolisers [EM] and reduced metabolisers [RM]) on HPR status was also assessed. HPR (PRU ≥240) following the clopidogrel LD (prior to the prasugrel LD) was 58.5% in the combined clopidogrel LD groups. No significant difference was noted when stratified by time between the clopidogrel and prasugrel LDs (≤6 hs vs>6 h). At 6 h following the 2nd loading dose in the combined prasugrel LD groups, HPR was 7.1%, with 0% HPR by 72 h. There was no significant effect of CYP2C19 genotype on pharmacodynamic (PD) response following either prasugrel LD treatments at any time point, regardless of whether it was preceded by a clopidogrel 600-mg LD. In conclusion, in this study, patients with ACS intended for PCI showed a high prevalence of HPR after clopidogrel 600-mg LD regardless of metaboliser status. When prasugrel LD was added, HPR decreased substantially by 6 h, and was not seen by 72 h.
- Published
- 2014
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19. Clopidogrel metaboliser status based on point-of-care CYP2C19 genetic testing in patients with coronary artery disease.
- Author
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Erlinge D, James S, Duvvuru S, Jakubowski JA, Wagner H, Varenhorst C, Tantry US, Brown PB, Small D, Moser BA, Sundseth SS, Walker JR, Winters KJ, and Gurbel PA
- Subjects
- Adolescent, Aged, Clopidogrel, Coronary Artery Disease genetics, Female, Genotype, High-Throughput Screening Assays, Humans, Inactivation, Metabolic genetics, International Cooperation, Male, Middle Aged, Point-of-Care Systems, Polymorphism, Genetic, Ticlopidine pharmacokinetics, Ticlopidine therapeutic use, Treatment Outcome, Young Adult, Coronary Artery Disease drug therapy, Cytochrome P-450 CYP2C19 genetics, Genetic Testing methods, Ticlopidine analogs & derivatives
- Abstract
We compared results obtained with the Nanosphere Verigene® System, a novel point-of-care (POC) genetic test capable of analysing 11 CYP2C19 variants within 3 hours, to an established, validated genotyping method (Affymetrix™ DMET+; reference assay) for identifying extensive and reduced metabolisers of clopidogrel. Based on genotyping, patients (N=82) with stable coronary artery disease on clopidogrel 75 mg daily were defined as extensive metabolisers (*1/*1, *1/*17, *17/*17), reduced metabolisers (*1/*2, *1/*8, *2/*2, *2/*3), or of indeterminate metaboliser status (*2/*17). Pharmacokinetic exposure to clopidogrel's active metabolite and pharmacodynamic measures with P2Y12 reaction units (PRU) (VerifyNow®P2Y12 assay) and VASP PRI (PRI) were also assessed. There was a 99.9% overall concordance of marker-level data between the Nanosphere Verigene and DMET+ systems in identifying the CYP2C19 variants and 100% agreement in classifying the patients as extensive (n=59) or reduced metabolisers (n=15). Extensive metabolisers had significantly higher active metabolite exposure than reduced metabolisers (LS means 12.6 ng*h/ml vs 7.7 ng*h/ml; p<0.001). Extensive metabolisers also had lower PRU (LS means 158 vs 212; p=0.003) and VASP PRI (LS means 48% vs 63%, p=0.01) compared to reduced metabolisers. Rates of high on-treatment platelet reactivity were higher in reduced metabolisers compared to extensive metabolisers (VASP PRI ≥ 50%: 79% vs 47%; PRU >235: 33% vs 16%). The Nanosphere Verigene CBS system identified 11 CYP2C19 alleles in less than 3 hours with a high degree of accuracy when compared to a conventional method, and was further validated against pharmacokinetic and pharmacodynamic phenotypes.
- Published
- 2014
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20. Enhanced active metabolite generation and platelet inhibition with prasugrel compared to clopidogrel regardless of genotype in thienopyridine metabolic pathways.
- Author
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Braun OÖ, Angiolillo DJ, Ferreiro JL, Jakubowski JA, Winters KJ, Effron MB, Duvvuru S, Costigan TM, Sundseth S, Walker JR, Saucedo JF, Kleiman NS, and Varenhorst C
- Subjects
- ATP Binding Cassette Transporter, Subfamily B, ATP Binding Cassette Transporter, Subfamily B, Member 1 genetics, ATP Binding Cassette Transporter, Subfamily B, Member 1 metabolism, Aged, Alleles, Aryl Hydrocarbon Hydroxylases genetics, Aryldialkylphosphatase genetics, Aryldialkylphosphatase metabolism, Biotransformation genetics, Blood Platelets physiology, Cell Adhesion Molecules metabolism, Cells, Cultured, Clopidogrel, Coronary Artery Disease genetics, Cytochrome P-450 CYP2C19, Female, Humans, Male, Microfilament Proteins metabolism, Middle Aged, Phosphoproteins metabolism, Platelet Activation drug effects, Polymorphism, Genetic, Prasugrel Hydrochloride, Prospective Studies, Receptors, Purinergic P2Y12 metabolism, Ticlopidine administration & dosage, Vasodilator-Stimulated Phosphoprotein, Aryl Hydrocarbon Hydroxylases metabolism, Blood Platelets drug effects, Coronary Artery Disease drug therapy, Piperazines administration & dosage, Pyridines metabolism, Thiophenes administration & dosage, Ticlopidine analogs & derivatives
- Abstract
Clopidogrel response varies according to the presence of genetic polymorphisms. The CYP2C19*2 allele has been associated with impaired response; conflicting results have been reported for CYP2C19*17, ABCB1, and PON1 genotypes. We assessed the impact of CYP2C19, PON1, and ABCB1 polymorphisms on clopidogrel and prasugrel pharmacodynamic (PD) and pharmacokinetic (PK) parameters. Aspirin-treated patients (N=194) with coronary artery disease from two independent, prospective, randomised, multi-centre studies comparing clopidogrel (75 mg) and prasugrel (10 mg) were genotyped and classified by predicted CYP2C19 metaboliser phenotype (ultra metabolisers [UM] = *17 carriers; extensive metabolisers [EM] = *1/1 homozygotes; reduced metabolisers [RM] = *2 carriers). ABCB1 T/T and C/T polymorphisms and PON1 A/A, A/G and G/G polymorphisms were also genotyped. PD parameters were assessed using VerifyNow® P2Y12 and vasodilator stimulated phosphoprotein (VASP) expressed as platelet reactivity index (PRI) after 14 days of maintenance dosing. Clopidogrel and prasugrel active metabolite (AM) exposure was calculated in a cohort of 96 patients. For clopidogrel, genetic variants in CYP2C19, but not ABCB1 or PON1, affected PK and PD. For prasugrel, none of the measured genetic variants affected PK or PD. Compared with clopidogrel, platelet inhibition with prasugrel was greater even in the CYP2C19 UM phenotype. Prasugrel generated more AM and achieved greater platelet inhibition than clopidogrel irrespective of CYP2C19, ABCB1, and PON1 polymorphisms. The lack of effect from genetic variants on prasugrel AM generation or antiplatelet activity is consistent with previous studies in healthy volunteers and is consistent with improved efficacy in acute coronary syndrome patients managed with percutaneous coronary intervention.
- Published
- 2013
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21. The effect of change in spectral slope and formant frequencies on the perception of loudness.
- Author
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Duvvuru S and Erickson M
- Subjects
- Humans, Loudness Perception, Speech Acoustics
- Abstract
Objective/hypothesis: This study attempts to understand how changes in spectral slope and formant frequency influence changes in perceived loudness. It was hypothesized that voices synthesized with steeper spectral slopes will be perceived as less loud than voices synthesized with less steep spectral slopes, in spite of the fact that they are of equal root mean square (RMS) amplitude. It was also hypothesized that stimuli with higher formant patterns will be perceived as louder than those with lower formant patterns, in spite of the fact that they are of equal RMS amplitude., Study Design: Repeated measures factorial design., Methods: For the pitches A3, C4, B4, and F5, three different source signals were synthesized with varying slopes of -9, -12, and -15 dB/octave using a frequency vibrato rate of 5.6 Hz and a frequency vibrato extent of 50 cents. Each of the three source signals were filtered using two formant patterns, a lower formant pattern typical of a mezzo-soprano (pattern A) and a higher formant pattern typical of a soprano (pattern B) for the vowel /a/. For each pitch, the six stimuli were combined into all possible pairs and normalized to equal RMS amplitude. Listeners were presented with 120 paired stimuli (60 pairs repeated twice). The listener's task was to indicate whether the first or second stimulus in the pair was louder., Results: Generally, as the spectral slope decreased, perceived loudness increased, with the magnitude of the perceived difference in loudness being related to the degree of difference in spectral slope. Likewise, at all pitches except A3, perceived loudness increased as formant frequency increased., Conclusion: RMS amplitude is an important predictor of loudness perception, but many other factors also affect the perception of this important vocal parameter. Spectral composition is one such factor and must be considered when using loudness perception in the process of clinical diagnostics., (Copyright © 2013 The Voice Foundation. Published by Mosby, Inc. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
22. Decrease in high on-treatment platelet reactivity (HPR) prevalence on switching from clopidogrel to prasugrel: insights from the switching anti-platelet (SWAP) study.
- Author
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Saucedo JF, Angiolillo DJ, DeRaad R, Frelinger AL 3rd, Gurbel PA, Costigan TM, Jakubowski JA, Ojeh CK, Duvvuru S, and Effron MB
- Subjects
- Acute Coronary Syndrome blood, Aged, Aryl Hydrocarbon Hydroxylases genetics, Aryl Hydrocarbon Hydroxylases metabolism, Blood Platelets drug effects, Blood Platelets metabolism, Cell Adhesion Molecules blood, Clopidogrel, Cytochrome P-450 CYP2C19, Double-Blind Method, Female, Genotype, Humans, Male, Microfilament Proteins blood, Middle Aged, Pharmacogenetics, Phenotype, Phosphoproteins blood, Piperazines adverse effects, Piperazines metabolism, Platelet Aggregation drug effects, Platelet Aggregation Inhibitors adverse effects, Platelet Aggregation Inhibitors metabolism, Platelet Function Tests, Prasugrel Hydrochloride, Prospective Studies, Purinergic P2Y Receptor Antagonists adverse effects, Purinergic P2Y Receptor Antagonists metabolism, Receptors, Purinergic P2Y12 blood, Receptors, Purinergic P2Y12 drug effects, Thiophenes adverse effects, Thiophenes metabolism, Ticlopidine administration & dosage, Ticlopidine adverse effects, Ticlopidine metabolism, Treatment Outcome, Vasodilator-Stimulated Phosphoprotein, Acute Coronary Syndrome drug therapy, Drug Substitution, Piperazines administration & dosage, Platelet Aggregation Inhibitors administration & dosage, Purinergic P2Y Receptor Antagonists administration & dosage, Thiophenes administration & dosage, Ticlopidine analogs & derivatives
- Abstract
The prevalence of high platelet reactivity (HPR) in patients who have switched from clopidogrel to prasugrel during maintenance phase after an acute coronary syndrome (ACS) event is unknown. Therefore, the effect of switching from clopidogrel to prasugrel on the prevalence of HPR was evaluated. This analysis from the previously reported SWAP (SWitching Anti Platelet) study assessed HPR at baseline, 2 and 24 hours, and seven days after switching from clopidogrel to prasugrel maintenance dose (MD), with or without a prasugrel loading dose (LD) using four definitions: maximum platelet aggregation (MPA) >65% (primary endpoint), MPA >50%, P2Y12 reaction units (PRU) >235, and platelet reactivity index (PRI) ≥ 50%. A total of 95 patients were available for analysis; 56 patients provided DNA for genetic assessments of cytochrome P450 (CYP) 2C19. There were 26 (27.4%) patients with HPR at the end of the clopidogrel run-in (defined as MPA >65%). The HPR prevalence varied by each definition and ranged from 19% (PRU >235) to 68% (PRI ≥ 50 %). A significantly higher HPR prevalence was observed during clopidogrel versus the combined prasugrel therapy groups at seven days as measured by MPA >65% (21.2% vs. 4.5%, p<0.05), PRU >235 (18.8% vs. 0%, p=0.001), and PRI ≥ 50 % (66.7% vs. 7.9%, p<0.0001). There was a significantly higher percentage of subjects carrying at least one reduced function allele with HPR measured by MPA >65% (p=0.02) or PRU >235 (p=0.05) than non-carriers with HPR. Switching ACS patients during maintenance clopidogrel therapy to prasugrel with or without an LD is associated with a reduced HPR prevalence and may provide an alternative strategy to treat patients with HPR, independent of CYP2C19 genotype.
- Published
- 2013
- Full Text
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23. The major locus for mouse adenovirus susceptibility maps to genes of the hematopoietic cell surface-expressed LY6 family.
- Author
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Spindler KR, Welton AR, Lim ES, Duvvuru S, Althaus IW, Imperiale JE, Daoud AI, and Chesler EJ
- Subjects
- Alleles, Animals, Antigens, Ly biosynthesis, Female, Hematopoietic Stem Cells metabolism, Male, Mice, Mice, Inbred A, Mice, Inbred BALB C, Mice, Inbred C3H, Adenoviridae genetics, Antigens, Ly genetics, Chromosome Mapping methods, Genetic Predisposition to Disease, Hematopoietic Stem Cells immunology, Multigene Family immunology, Quantitative Trait Loci immunology
- Abstract
Susceptibility to mouse adenovirus type 1 is associated with the major quantitative trait locus Msq1. Msq1 was originally mapped to a 13-Mb region of mouse chromosome (Chr) 15 in crosses between SJL/J and BALB/cJ inbred mice. We have now narrowed Msq1 to a 0.75-Mb interval from 74.68 to 75.43 Mb, defined by two anonymous markers, rs8259436 and D15Spn14, using data from 1396 backcross mice. The critical interval includes 14 Ly6 or Ly6-related genes, including Ly6a (encoding Sca-1/TAP), Ly6e (Sca-2/Tsa1), Ly6g (Gr-1), and gpihbp1 (GPI-anchored high-density lipoprotein-binding protein 1), as well as the gene encoding an aldosterone synthase (Cyp11b2). The Ly6 family members are attractive candidates for virus susceptibility genes because their products are GPI-anchored membrane proteins expressed on lymphoid and myeloid cells, with proposed functions in cell adhesion and cell signaling. To determine interstrain variation in susceptibility and produce additional resources for cloning Msq1, we assayed the susceptibility phenotype of four previously untested inbred mouse strains. Susceptibility of strain 129S6/SvEvTac was subsequently localized to the Ly6 complex region, using polymorphic genetic markers on Chr 15 in a population of 271 (129S6/SvEvTac x BALB/cJ)F(1) x BALB/cJ backcross mice. We identified a major 129S6/SvEvTac susceptibility allele, Msq1(129S6), on Chr 15 in the same region as Msq1(SJL). The results indicate that a major host factor in mouse adenovirus type 1 susceptibility is likely to be a member of the Ly6 gene family.
- Published
- 2010
- Full Text
- View/download PDF
24. A preference for edgewise interactions between aromatic rings and carboxylate anions: the biological relevance of anion-quadrupole interactions.
- Author
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Jackson MR, Beahm R, Duvvuru S, Narasimhan C, Wu J, Wang HN, Philip VM, Hinde RJ, and Howell EE
- Subjects
- Benzene chemistry, Energy Transfer, Formates chemistry, Hydrogen Bonding, Ligands, Protein Folding, Quantum Theory, Amino Acids, Aromatic chemistry, Amino Acids, Dicarboxylic chemistry, Chemistry, Physical methods, Proteins chemistry
- Abstract
Noncovalent interactions are quite important in biological structure-function relationships. To study the pairwise interaction of aromatic amino acids (phenylalanine, tyrosine, tryptophan) with anionic amino acids (aspartic and glutamic acids), small molecule mimics (benzene, phenol or indole interacting with formate) were used at the MP2 level of theory. The overall energy associated with an anion-quadrupole interaction is substantial (-9.5 kcal/mol for a benzene-formate planar dimer at van der Waals contact distance), indicating the electropositive ring edge of an aromatic group can interact with an anion. Deconvolution of the long-range coplanar interaction energy into fractional contributions from charge-quadrupole interactions, higher-order electrostatic interactions, and polarization terms was achieved. The charge-quadrupole term contributes between 30 to 45% of the total MP2 benzene-formate interaction; most of the rest of the interaction arises from polarization contributions. Additional studies of the Protein Data Bank (PDB Select) show that nearly planar aromatic-anionic amino acid pairs occur more often than expected from a random angular distribution, while axial aromatic-anionic pairs occur less often than expected; this demonstrates the biological relevance of the anion-quadrupole interaction. While water may mitigate the strength of these interactions, they may be numerous in a typical protein structure, so their cumulative effect could be substantial.
- Published
- 2007
- Full Text
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25. Envirometrics. Part I: Modeling of water salinity and air quality data.
- Author
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Braibanti A, Gollapalli NR, Jonnalagaddaj SB, Duvvuru S, and Rupenaguntla SR
- Subjects
- Environmental Monitoring methods, Fresh Water analysis, Least-Squares Analysis, Multivariate Analysis, New York, North Carolina, Air Pollutants analysis, Models, Theoretical, Water Pollutants, Chemical analysis
- Abstract
Envirometrics utilises advanced mathematical, statistical and information tools to extract information. Two typical environmental data sets are analysed using MVATOB (Multi Variate Analysis TOol Box). The first data set corresponds to the variable river salinity. Least median squares (LMS) detected the outliers whereas linear least squares (LLS) could not detect and remove the outliers. The second data set consists of daily readings of air quality values. Outliers are detected by LMS and unbiased regression coefficients are estimated by multi-linear regression (MLR). As explanatory variables are not independent, principal component regression (PCR) and partial least squares regression (PLSR) are used. Both examples demonstrate the superiority of LMS over LLS.
- Published
- 2001
26. Isolation of a human serum protein that inhibits the growth of Cryptococcus neoformans.
- Author
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Duvvuru S, Brummer E, Morelli R, and Stevens DA
- Subjects
- Antifungal Agents chemistry, Antifungal Agents isolation & purification, Blood Proteins chemistry, Chromatography, Gel, Chromatography, Ion Exchange, Cryptococcus neoformans growth & development, Culture Media, Electrophoresis, Polyacrylamide Gel, Humans, Antifungal Agents pharmacology, Blood Proteins isolation & purification, Blood Proteins pharmacology, Cryptococcus neoformans drug effects
- Abstract
Human serum at 5 to 10% (v/v) in tissue culture medium RPMI-1640, inhibits the growth of Cryptococcus neoformans by 80 to 93%. Serum fractionated on molecular sieve columns (Sephadex G-200) yielded an active protein fraction. This fraction at 100 micrograms protein/ml inhibited the growth of C. neoformans by 54%. When an active G-200 fraction was applied to a dye affinity column (Affi-Gel Blue) the fraction with inhibitory activity was bound by the column and was eluted with 1.4 M NaCl in 0.1 M phosphate buffer (pH 7.4). The bound fraction at 62.5 micrograms protein/ml inhibited C. neoformans growth by 82%. On native polyacrylamide gel electrophoresis (Nu-PAGE) the bound fraction migrated as a major and a minor band. Under the reducing conditions of sodium dodecyl sulfate (SDS)-PAGE the bound fraction yielded 4 prominent bands with MW ranging from 175 kDa to 45 kDa. Purification of the active Sephadex G-200 peak was achieved using an anion exchange column (DEAE-Sephacel). Protein eluted with 0.1 M NaCl had strong anticryptococcal activity (12.5 micrograms/ml, 79% inhibition), which in SDS-PAGE migrated as a single band with an approximate MW of 85 kDA. This protein appears important in natural host resistance to C. neoformans and polymorphisms or deficiencies may have epidemiologic and diagnostic relevance.
- Published
- 1998
- Full Text
- View/download PDF
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