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Stokes phenomenon refers to the fact that an asymptotic expansion of complex functions can differ in different regions of the complex plane, and that beyond the so-called Stokes lines the expansion has an unphysical divergence. An important special case is when the Stokes lines emanate from phase space caustics of a complex trajectory manifold. In this case, symmetry determines that to second order there is a double coverage of the space, one portion of which is unphysical. Building on the seminal but laconic findings of Adachi, we show that the deviation from second order can be used to rigorously determine the Stokes lines and therefore the region of the space that should be removed. The method has applications to wavepacket reconstruction from complex valued classical trajectories. With a rigorous method in hand for removing unphysical divergences, we demonstrate excellent wavepacket reconstruction for the Morse, Quartic, Coulomb, and Eckart systems.
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Complex-valued classical trajectories in complex time encounter singular times at which the momentum diverges. A closed time contour around such a singular time may result in final values for q and p that differ from their initial values. In this work, we develop a calculus for determining the exponent and prefactor of the asymptotic time dependence of p from the singularities of the potential as the singularity time is approached. We identify this exponent with the number of singularity loops giving distinct solutions to Hamilton's equations of motion. The theory is illustrated for the Eckart, Coulomb, Morse, and quartic potentials. Collectively, these potentials illustrate a wide variety of situations: poles and essential singularities at finite and infinite coordinate values. We demonstrate quantitative agreement between analytical and numerical exponents and prefactors, as well as the connection between the exponent and the time circuit count. This work provides the theoretical underpinnings for the choice of time contours described in the studies of Doll et al. [J. Chem. Phys. 58(4), 1343-1351 (1973)] and Petersen and Kay [J. Chem. Phys. 141(5), 054114 (2014)]. It also has implications for wavepacket reconstruction from complex classical trajectories when multiple branches of trajectories are involved.
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BACKGROUND: Plasma triglyceride levels are heritable and are correlated with the risk of coronary heart disease. Sequencing of the protein-coding regions of the human genome (the exome) has the potential to identify rare mutations that have a large effect on phenotype. METHODS: We sequenced the protein-coding regions of 18,666 genes in each of 3734 participants of European or African ancestry in the Exome Sequencing Project. We conducted tests to determine whether rare mutations in coding sequence, individually or in aggregate within a gene, were associated with plasma triglyceride levels. For mutations associated with triglyceride levels, we subsequently evaluated their association with the risk of coronary heart disease in 110,970 persons. RESULTS: An aggregate of rare mutations in the gene encoding apolipoprotein C3 (APOC3) was associated with lower plasma triglyceride levels. Among the four mutations that drove this result, three were loss-of-function mutations: a nonsense mutation (R19X) and two splice-site mutations (IVS2+1GâA and IVS3+1GâT). The fourth was a missense mutation (A43T). Approximately 1 in 150 persons in the study was a heterozygous carrier of at least one of these four mutations. Triglyceride levels in the carriers were 39% lower than levels in noncarriers (P<1×10(-20)), and circulating levels of APOC3 in carriers were 46% lower than levels in noncarriers (P=8×10(-10)). The risk of coronary heart disease among 498 carriers of any rare APOC3 mutation was 40% lower than the risk among 110,472 noncarriers (odds ratio, 0.60; 95% confidence interval, 0.47 to 0.75; P=4×10(-6)). CONCLUSIONS: Rare mutations that disrupt APOC3 function were associated with lower levels of plasma triglycerides and APOC3. Carriers of these mutations were found to have a reduced risk of coronary heart disease. (Funded by the National Heart, Lung, and Blood Institute and others.).
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Apolipoproteína C-III/genética , Enfermedad Coronaria/genética , Mutación , Triglicéridos/sangre , Apolipoproteína C-III/sangre , Población Negra/genética , Enfermedad Coronaria/sangre , Exoma , Genotipo , Heterocigoto , Humanos , Hígado/patología , Factores de Riesgo , Análisis de Secuencia de ADN , Población Blanca/genéticaRESUMEN
BACKGROUND: Systolic blood pressure (SBP) increases steadily with age and bears an independent continuous relationship with the incidence of cardiovascular events. Low-grade inflammation is a suspected pathomechanism causing vascular aging and promote coronary artery disease (CAD). Recent animal studies give evidence that Toll-like receptor 4 (TLR4) modulate inflammation and contribute to age-dependent SBP increase. However, there are no data about TLR4 and age-dependent blood pressure increase in human. METHODS AND RESULTS: We therefor investigate a human cohort of 2679 patients with CAD aged between 50-80 years. Genotypes were determined for the TLR4 single nucleotide polymorphism rs4986790 (TLR4 896A/G). Patients were stratified according to tertiles of age and the upper tertile was compared to lower tertiles. In this cohort we show that older patients with the TLR4 896 G allele had significantly lower SBP (TLR4 G allele carriers: 148.2 ± 30.4 mmHg versus A/A allele carrier: 154.9 ± 27.2 mmHg; P < 0.05) and lower pulse pressure (TLR4 G allele carriers: 69.1 ± 29.7 mmHg versus A/A allele carrier: 75.5 ± 26.4 mmHg; P < 0.05) as compared to TLR4 896A/A allele carrier. CONCLUSION: We demonstrate an association between the TLR4 SNP rs4986790 genotype and age-dependant blood pressure increase in patients with coronary artery disease.
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We present a potential energy surface fitting scheme based on multiplicative artificial neural networks. It has the sum of products form required for efficient computation of the dynamics of multidimensional quantum systems with the multi configuration time dependent Hartree method. Moreover, it results in analytic potential energy matrix elements when combined with quantum dynamics methods using Gaussian basis functions, eliminating the need for a local harmonic approximation. Scaling behavior with respect to the complexity of the potential as well as the requested accuracy is discussed.
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Percutaneous coronary intervention (PCI) has become an effective therapy to treat obstructive coronary artery diseases (CAD). However, one of the major drawbacks of PCI is the occurrence of restenosis in 5-25% of all initially treated patients. Restenosis is defined as the re-narrowing of the lumen of the blood vessel, resulting in renewed symptoms and the need for repeated intervention. To identify genetic variants that are associated with restenosis, a genome-wide association study (GWAS) was conducted in 295 patients who developed restenosis (cases) and 571 who did not (controls) from the GENetic Determinants of Restenosis (GENDER) study. Analysis of ~550 000 single nucleotide polymorphisms (SNPs) in GENDER was followed by a replication phase in three independent case-control populations (533 cases and 3067 controls). A potential susceptibility locus for restenosis at chromosome 12, including rs10861032 (P(combined) = 1.11 × 10(-7)) and rs9804922 (P(combined) = 1.45 × 10(-6)), was identified in the GWAS and replication phase. In addition, both SNPs were also associated with coronary events (rs10861032, P(additive) = 0.005; rs9804922, P(additive) = 0.023) in a trial based cohort set of elderly patients with (enhanced risk of) CAD (PROSPER) and all-cause mortality in PROSPER (rs10861032, P(additive) = 0.007; rs9804922, P(additive) = 0.013) and GENDER (rs10861032, P(additive) = 0.005; rs9804922, P(additive) = 0.023). Further analysis suggests that this locus could be involved in regulatory functions.
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Angioplastia Coronaria con Balón , Cromosomas Humanos Par 12/genética , Reestenosis Coronaria/genética , Reestenosis Coronaria/terapia , Sitios Genéticos/genética , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Anciano , Reestenosis Coronaria/mortalidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple/genéticaRESUMEN
Relatively low numbers of kringle 4 type 2 repeats in apolipoprotein(a) and specific haplotypes of the SLC22A3-LPAL2-LPA region on chromosome 6 are associated with an increased risk of coronary disease. We examined the possibility that rs3798220 and rs10455872, short variations located in LPA [the apolipoprotein(a) gene], and related to the number of kringle 4 type 2 repeats, may serve as markers for the association between haplotypes and acute myocardial infarction. Genotypes were determined with TaqMan assays in a sample of 2136 cases and 1211 controls. The minor alleles of rs3798220 and rs10455872 were associated with increased risks (rs3798220-C: adjusted OR 2.14, 95% CI, 1.37-3.33, P = 0.00080; rs10455872-G: adjusted OR 1.74, 95% CI 1.36-2.24, P < 0.00001). After adjustments were made for potential confounders, none of nine polymorphisms included in a haplotype analysis were singly related to disease. Two risk haplotypes were identified; one (CCTTGTGTG; OR 1.25, 95% CI 1.08-1.45, P = 0.0022) was correlated with rs3798220-C and the other (CCCTGGATC; OR 1.65, 95% CI 1.14-2.38, P = 0.0074) with rs10455872-G. Thus, the findings allowed for a more precise definition of risk-associated markers: specific nucleotides in LPA instead of standard haplotypes defined by noneffective variants from the extensive SLC22A3-LPAL2-LPA region.
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Apolipoproteínas A/genética , Infarto del Miocardio/genética , Polimorfismo de Nucleótido Simple , Anciano , Anciano de 80 o más Años , Femenino , Predisposición Genética a la Enfermedad , Haplotipos , Humanos , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND: The 9p21.3 locus is strongly associated with the risk of coronary artery disease (CAD) and with type 2 diabetes (T2D). We investigated the association of 9p21.3 variants with severity of CAD (defined by the number of vessel diseased [VD]) in the presence and absence of T2D. METHODS: We tested 11 9p21.3-variants for association in a white Italian study (N = 2,908), and carried out replication in 2 independent white populations, a German study (N = 2,028) and a Canadian Study (N=950). SNP association and permutation analyses were conducted. RESULTS: We identified two 9p21.3-variants, rs4977574 (P < 4×10(-4)) and rs2383207 (P < 1.5×10(-3)) that were associated with severity of CAD in subjects without T2D. Association of rs4977574 with severity of CAD was confirmed in the Canadian Study. Results from subgroup analysis among patients with T2D showed an interaction between rs10738610 and T2D with P = 4.82×10(-2). Further investigation showed that rs10738610 (P < 1.99×10(-2)) was found to be significantly associated with severity of CAD in subjects with T2D. CONCLUSIONS: The 9p21.3 locus is significantly associated with severity of CAD. The number of associations of 9p21.3 variants with severity of CAD is variable to the presence and absence of T2D. In a CAD-susceptible region of 115 kb, there is only one variant associated with the severity of coronary vessel disease in the presence of type 2 diabetes.
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Cromosomas Humanos Par 9 , Enfermedad de la Arteria Coronaria/genética , Diabetes Mellitus Tipo 2/complicaciones , Niño , Enfermedad de la Arteria Coronaria/complicaciones , Enfermedad de la Arteria Coronaria/patología , Humanos , Índice de Severidad de la EnfermedadRESUMEN
A wide variety of molecular systems that have recently come into the reach of experimental and theoretical investigation is dominated by quantum phenomena. However, even state of the art quantum propagation techniques are either unsuitable for general application to molecular systems with strong interference and tunneling characteristics or are computationally prohibitive for systems with more than a few degrees of freedom. In this Letter, we introduce a novel quantum propagation technique with wide applicability, controllable accuracy, and efficient utilization of computational resources. Its performance is validated for tunneling and dissociating systems with 1, 2, and 3 degrees of freedom, and the scaling behavior with respect to system dimensionality and requested accuracy is discussed.
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AIMS: In clopidogrel-treated patients undergoing coronary stenting, high on-treatment platelet reactivity was linked to a higher risk of stent thrombosis (ST). Platelet response to clopidogrel is significantly influenced by genetic factors. Recently published findings showed a highly significant impact of a common polymorphism (Q192R) within the paraoxonase-1 (PON1) gene on clopidogrel treatment efficacy but no influence of the CYP2C19*2 genetic variant as previously demonstrated. The aim of this study was to assess the impact of the PON1 Q192R genotype in parallel to that of CYP2C19*2 on the antiplatelet effect of clopidogrel and the risk of ST in clopidogrel-treated patients. METHODS AND RESULTS: In 1524 patients undergoing percutaneous coronary intervention, ADP-induced platelet aggregation was assessed in relation to PON1 Q192R and CYP2C19*2 genotypes. The clinical impact of genetic variants was investigated by comparing genotype frequencies of both genetic variants in a registry of 127 cases with early ST vs. an early ST-free control cohort (n = 1439). For PON1 Q192R genotypes, platelet aggregation values were similar across all genotype groups (P = 0.65). For CYP2C19*2 genotypes, significantly higher aggregation values were found in CYP2C19 wt/*2 and *2/*2 patients when compared with wt/wt allele carriers (P < 0.0001). Comparing genotype frequencies between ST cases and controls, no differences were observed for PON1 Q192R genotype distributions (P = 0.23), whereas the genotype distribution differed for CYP2C19*2 genotypes (P = 0.019). CONCLUSION: The PON1 Q192R genotype did not influence platelet response to clopidogrel or the risk of ST in clopidogrel-treated patients, whereas the CYP2C19*2 genotype impacted on both antiplatelet effect of clopidogrel and risk of coronary ST.
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Hidrocarburo de Aril Hidroxilasas/genética , Arildialquilfosfatasa/genética , Oclusión de Injerto Vascular/genética , Inhibidores de Agregación Plaquetaria/uso terapéutico , Polimorfismo Genético/genética , Ticlopidina/análogos & derivados , Anciano , Angioplastia Coronaria con Balón/métodos , Aspirina/uso terapéutico , Clopidogrel , Enfermedad Coronaria/sangre , Enfermedad Coronaria/genética , Enfermedad Coronaria/terapia , Citocromo P-450 CYP2C19 , Femenino , Frecuencia de los Genes , Genotipo , Heterocigoto , Homocigoto , Humanos , Masculino , Persona de Mediana Edad , Agregación Plaquetaria/efectos de los fármacos , Estudios Prospectivos , Stents , Ticlopidina/uso terapéuticoRESUMEN
BACKGROUND: The cytochrome P450 (CYP) 2C19 isoenzyme plays an important role in clopidogrel metabolization. A recently explored CYP2C19*17 allelic variant has been linked to increased transcriptional activity, resulting in extensive metabolization of CYP2C19 substrates, which may lead to an enhanced platelet response to clopidogrel treatment. The aim of this study was to assess the impact of CYP2C19*17 on ADP-induced platelet aggregation, the risk of bleeding, and stent thrombosis in clopidogrel-treated patients undergoing percutaneous coronary intervention. METHODS AND RESULTS: The study population included 1524 patients undergoing percutaneous coronary intervention after pretreatment with 600 mg clopidogrel. Genotypes were determined with a TaqMan assay. ADP-induced platelet aggregation was assessed on a Multiplate analyzer. The primary clinical safety end point was the 30-day incidence of bleeding defined according to Thrombolysis in Myocardial Infarction criteria, and the primary clinical efficacy end point was the 30-day incidence of stent thrombosis. For both heterozygous (*wt/*17; n=546) and homozygous (*17/*17; n=76) allele carriers, significantly lower ADP-induced platelet aggregation values were found compared with wild-type homozygotes (*wt/*wt; n=902; P=0.039 and P=0.008, respectively). CYP2C19*17 allele carriage was significantly associated with an increased risk of bleeding; the highest risk was observed for CYP2C19*17 homozygous patients (P=0.01, chi(2) test for trend). Multivariate analysis confirmed the independent association of CYP2C19*17 allele carriage with platelet aggregation values (P<0.001) and the occurrence of bleeding (P=0.006). No significant influence of CYP2C19*17 on the occurrence of stent thrombosis was found (P=0.79). CONCLUSIONS: CYP2C19*17 carrier status is significantly associated with enhanced response to clopidogrel and an increased risk of bleeding.
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Hidrocarburo de Aril Hidroxilasas/genética , Enfermedad de la Arteria Coronaria/terapia , Trombosis Coronaria/prevención & control , Hemorragia/epidemiología , Agregación Plaquetaria/genética , Stents , Ticlopidina/análogos & derivados , Anciano , Hidrocarburo de Aril Hidroxilasas/metabolismo , Clopidogrel , Citocromo P-450 CYP2C19 , Femenino , Estudios de Seguimiento , Frecuencia de los Genes/genética , Genotipo , Heterocigoto , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Inhibidores de Agregación Plaquetaria/uso terapéutico , Polimorfismo Genético/genética , Factores de Riesgo , Ticlopidina/metabolismo , Ticlopidina/uso terapéutico , Resultado del TratamientoRESUMEN
Interleukin 18 is an important mediator of inflammation and has been associated with the development and aggravation of cardiovascular diseases. We report that common variation in the interleukin 18 gene is related to acute myocardial infarction, a frequent clinical manifestation of atherosclerosis and thrombosis in coronary arteries. In a population of European, mainly (90%) German, ancestry (2136 cases with acute myocardial infarction and 1211 controls), the association was based on specific alleles and haplotypes derived from a set of six tagging single nucleotide polymorphisms. The rs1946519-G (located in the 5' upstream region), rs360717-C (exon 1), rs5744241-G (intron 1), rs1834481-C (intron 3), and rs3882891-A (intron 5) alleles (P≤0.039) and a haplotype (GCGCAG haplotype; P=0.0028) containing the GCGCA motif derived from these alleles were associated with an increased risk of AMI. Corresponding with this result, the complementary alleles (rs1946519-T, rs360717-T, rs5744241-A, rs1834481-G, and rs3882891-C) and a haplotype (TTAGCG haplotype; P=0.018) with the TTAGC motif showed protective effects. Haplotypes not including the GCGCA or TTAGC motif were not related to AMI (P≥0.22). These observations suggest that the interleukin 18 gene is a susceptibility locus for acute myocardial infarction, a finding of potential interest in the clinical practice.
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Predisposición Genética a la Enfermedad , Interleucina-18/genética , Infarto del Miocardio/genética , Polimorfismo de Nucleótido Simple/genética , Estudios de Casos y Controles , Cromosomas Humanos Par 11/genética , Femenino , Frecuencia de los Genes/genética , Sitios Genéticos/genética , Haplotipos/genética , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Fumar/genéticaRESUMEN
ABSTRACT: What is the nature of tunnelling? This yet unanswered question is as pertinent today as it was at the dawn of quantum mechanics. This article presents a cross section of current perspectives on the interpretation, computational modelling, and numerical investigation of tunnelling processes in attosecond physics as debated in the Quantum Battles in Attoscience virtual workshop 2020.
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A role of thrombospondins (TSPs) in atherosclerosis and thrombosis was suggested by associations of single nucleotide polymorphisms in the genes coding for TSP-1 (rs2228262; Asn700Ser), TSP-2 (rs8089; 3' untranslated region), and TSP-4 (rs1866389; Ala387Pro) with myocardial infarction (MI). However, these findings were not consistently confirmed in replication studies. We determined the genotypes related to these polymorphisms in a large case-control sample of MI and performed a meta-analysis of data obtained in the present sample and available from prior studies that included Europeans or Americans of European origin. In the population examined here, the carriers of the minor allele of the polymorphism in the TSP-2 gene (GG and TG genotypes) had a mildly statistically significant higher risk of MI than the homozygous carriers of the major allele (TT genotype) [adjusted odds ratio (OR) 1.19; 95% confidence interval (CI), 1.02 to 1.39]. In similar comparisons, no associations of the polymorphisms in the TSP-1 (adjusted OR 1.12; 95% CI, 0.93 to 1.35) and TSP-4 (adjusted OR 0.99; 95% CI, 0.85 to 1.16) genes with MI were observed. The meta-analysis included 6388 (TSP-1), 4930 (TSP-2), and 6978 (TSP-4) cases. None of the polymorphisms was found to be linked with the risk of MI. Thus, despite associations in certain individual studies, the synthesis of available evidence did not suggest that the TSP polymorphisms included in this study were associated with MI.
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Predisposición Genética a la Enfermedad , Infarto del Miocardio/genética , Polimorfismo de Nucleótido Simple , Trombospondina 1/genética , Trombospondinas/genética , Estudios de Casos y ControlesRESUMEN
BACKGROUND: The prodrug clopidogrel requires activation by cytochrome P-450 (CYP) enzymes for its antiplatelet effect. The genes encoding enzymes for clopidogrel activation are polymorphic, leading to reduced or increased function, depending on the respective genotype. Reduced-function alleles have been associated with an increase in cardiovascular events. METHODS: We tested the association of the presence of the ABCB1 (C/T) T-allele, CYP2C19*2 (G/A) A-allele, or CYP2C19*17 (C/T) T-allele with the primary end point of the need of clinically-driven target lesion revascularization (TLR) and the secondary end points of major adverse cardiovascular events (MACE; including death, myocardial infarction [MI], and TLR) at 1 year in a high-risk population of 928 patients with acute MI. RESULTS: Carriers of the CYP2C19*17 T-allele, with increased clopidogrel activation, had a 37% relative reduction in the TLR incidence, the primary end point (14.0% vs 22.3%, P = .002), and a 22% relative reduction of the secondary end point MACE (22.0% vs 28.1%, P = .04) compared with noncarriers, respectively. The association of the T-allele with TLR remained significant in the multivariate analysis (P = .001). The ABCB1 (C/T) and the CYP2C19*2 (G/A) polymorphisms were not associated with the incidence of TLR or MACE. CONCLUSIONS: Based on the genetic analysis in a high-risk population of acute MI patients with interventional treatment and continuous clopidogrel therapy, our study found a protective effect for carriers of an increased-function CYP2C19*17 T-allele with significantly lower rates of TLR and MACE. T-allele carriers with acute MI and increased clopidogrel activation had significantly reduced clinical event rates.
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Hidrocarburo de Aril Hidroxilasas/fisiología , Infarto del Miocardio/genética , Inhibidores de Agregación Plaquetaria/farmacocinética , Polimorfismo Genético/fisiología , Ticlopidina/análogos & derivados , Anciano , Alelos , Angioplastia Coronaria con Balón , Hidrocarburo de Aril Hidroxilasas/genética , Biotransformación , Enfermedades Cardiovasculares/genética , Enfermedades Cardiovasculares/terapia , Clopidogrel , Angiografía Coronaria , Reestenosis Coronaria/prevención & control , Citocromo P-450 CYP2C19 , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Infarto del Miocardio/terapia , Recurrencia , Reoperación , Stents , Accidente Cerebrovascular/genética , Ticlopidina/farmacocinéticaRESUMEN
The influence of a dissipative environment on scattering of a particle by a barrier is investigated by using the recently introduced bohmian mechanics with complex action [J. Chem. Phys. 125, 231103 (2006)]. An extension of this complex trajectory based formalism to include the interaction of the tunneling particle with an environment of harmonic oscillators with a continuous spectral density and at a certain finite temperature allows us to calculate transmission probabilities beyond the weak system bath coupling regime. The results display an increasing tunneling probability for energies below the barrier and a decreased transmission above the barrier due to the coupling. Furthermore, we demonstrate that solutions of a markovian master equation fail to do so in general.
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AIMS: Several studies have demonstrated that the mutant *2 allele of the CYP2C19 681G>A loss-of-function polymorphism is associated with diminished metabolization of clopidogrel into its active thiol metabolite and an attenuated platelet response to clopidogrel treatment. It is not known whether patients carrying the mutant CYP2C19*2 allele have a higher risk of stent thrombosis (ST) compared with homozygous CYP2C19*1 wild-type allele carriers following percutaneous coronary intervention (PCI). The aim of this study was to assess the impact of the CYP2C19 681G>A loss-of-function polymorphism on ST following PCI performed after pre-treatment with clopidogrel. METHODS AND RESULTS: The study population included 2485 consecutive patients undergoing coronary stent placement after pre-treatment with 600 mg of clopidogrel. Genotypes were determined with a TaqMan assay. The primary endpoint of the study was the incidence of definite ST within 30 days following PCI. Of the patients studied, 1805 (73%) were CYP2C19 wild-type homozygotes (*1/*1) and 680 (27%) carried at least one *2 allele (*1/*2 or *2/*2). The cumulative 30-day incidence of ST was significantly higher in CYP2C19*2 allele carriers (*1/*2 or *2/*2) vs. CYP2C19 wild-type homozygotes (*1/*1) [10 patients (1.5%) in CYP2C19*2 allele carriers vs. 7 (0.4%) in CYP2C19 wild-type homozygotes (*1/*1), HR 3.81, 95% CI 1.45-10.02, P = 0.007; P = 0.006 after adjustment for confounding variables]. The risk of ST was highest (2.1%) in patients with the CYP2C19 *2/*2 genotype (P = 0.002). CONCLUSION: CYP2C19*2 carrier status is significantly associated with an increased risk of ST following coronary stent placement.
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Angioplastia Coronaria con Balón , Hidrocarburo de Aril Hidroxilasas/genética , Enfermedad Coronaria/terapia , Oclusión de Injerto Vascular/genética , Polimorfismo Genético/genética , Stents , Anciano , Clopidogrel , Citocromo P-450 CYP2C19 , Femenino , Genotipo , Homocigoto , Humanos , Masculino , Inhibidores de Agregación Plaquetaria/metabolismo , Ensayos Clínicos Controlados Aleatorios como Asunto , Factores de Riesgo , Ticlopidina/análogos & derivados , Ticlopidina/metabolismoRESUMEN
OBJECTIVE: Fibrinogen has a role in inflammatory processes and participates in atherosclerotic plaque formation. Despite intensive investigation, there is no clear evidence for a role of variations in the genes coding for the fibrinogen-alpha, fibrinogen-beta, and fibrinogen-gamma polypeptide chains in myocardial infarction. We examined the association of haplotypes in the 50-kb fibrinogen gene region with myocardial infarction in 2 large case-control samples. METHODS AND RESULTS: Study sample 1 consisted of 3657 patients with myocardial infarction and 1211 control individuals and sample 2 comprised 1392 patients and 1392 controls. Haplotypes were inferred from genotype analyses of tagging single nucleotide polymorphisms dispersed among the fibrinogen genes. The frequencies of these haplotypes were not significantly different between the case and control groups in either sample (P > or = 0.07). In addition, haplotypes specific for individual fibrinogen genes were analyzed. No substantial differences in the frequencies of these haplotypes were observed between the groups (P > or = 0.13). Finally, haplotypes composed of SNPs that exhibited relatively low pairwise allelic associations among each other were examined. The proportions of the haplotypes were not significantly different between cases and controls (P > or = 0.12). CONCLUSIONS: A haplotype analysis did not reveal a link between genetic variations in the fibrinogen gene region and myocardial infarction.
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Fibrinógeno/genética , Infarto del Miocardio/genética , Polimorfismo de Nucleótido Simple , Anciano , Alelos , Estudios de Casos y Controles , Femenino , Frecuencia de los Genes , Variación Genética , Haplotipos , Humanos , Desequilibrio de Ligamiento , Masculino , Persona de Mediana Edad , Infarto del Miocardio/sangre , Infarto del Miocardio/etiología , Factores de RiesgoRESUMEN
The Caldeira-Leggett master equation for dissipative quantum dynamics has predominantly been implemented in phase space, where it plays the role of a quantum Fokker-Planck equation. Here we demonstrate the feasibility of a pure coordinate space implementation in the case of intermediate damping strength and temperature, for times long enough to observe thermal equilibration. After a thorough numerical investigation of the analytically solvable harmonic oscillator case, a Morse oscillator model is studied. This is a case in which a quantal phase space approach would be difficult to implement and we show how analytical results for thermal averages are reproduced to a surprisingly high degree.
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Química Física/métodos , Técnicas de Química Analítica/métodos , Simulación por Computador , Cinética , Modelos Estadísticos , Modelos Teóricos , Oscilometría , Teoría Cuántica , TemperaturaRESUMEN
BACKGROUND AND AIM: Previous studies have shown conflicting results regarding circulating homocysteine levels in patients with type 2 diabetes. METHODS AND RESULTS: This observational study included 2121 patients with angiographically proven coronary artery disease (507 patients with type 2 diabetes and 1614 patients without diabetes). Circulating homocysteine levels, methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism, renal function, presence of coronary artery disease (CAD) diagnosed by coronary angiography, and circulating folate and vitamin B12 status were assessed. Plasma homocysteine levels [median (25th; 75th percentile)] were significantly higher in patients with diabetes than in those without [12.4 micromol/L (9.9 micromol/L; 15.9 micromol/L) versus 11.7 micromol/L (9.6 micromol/L; 14.5 micromol/L), P=0.011]. Diabetes affected homocysteine levels only in patients with a glomerular filtration rate <90 mL/min [13.0 micromol/L (10.5 micromol/L; 16.7 micromol/L) in patients with diabetes versus 12.2 micromol/L (10.1 micromol/L; 15.2 micromol/L) in patients without diabetes, P=0.006] but not in those with a glomerular filtration rate > or = 90 mL/min [10.1 micromol/L (8.1 micromol/L; 12.4 micromol/L) versus 10.2 micromol/L (8.8 micromol/L; 12.3 micromol/L), P=0.267]. Multivariable analysis did not show an independent association between diabetes and homocysteine level (P=0.342). CONCLUSION: Circulating homocysteine levels are increased in patients with type 2 diabetes compared with non-diabetic patients due to a more diabetes-associated adverse risk profile rather than to diabetes itself.