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1.
Hum Mol Genet ; 32(3): 496-505, 2023 01 13.
Artículo en Inglés | MEDLINE | ID: mdl-36048866

RESUMEN

Prolyl hydroxylase (PHD) inhibitors are in clinical development for anaemia in chronic kidney disease. Epidemiological studies have reported conflicting results regarding safety of long-term therapeutic haemoglobin (Hgb) rises through PHD inhibition on risk of cardiovascular disease. Genetic variation in genes encoding PHDs can be used as partial proxies to investigate the potential effects of long-term Hgb rises. We used Mendelian randomization to investigate the effect of long-term Hgb level rises through genetically proxied PHD inhibition on coronary artery disease (CAD: 60 801 cases; 123 504 controls), myocardial infarction (MI: 42 561 cases; 123 504 controls) or stroke (40 585 cases; 406 111 controls). To further characterize long-term effects of Hgb level rises, we performed a phenome-wide association study (PheWAS) in up to 451 099 UK Biobank individuals. Genetically proxied therapeutic PHD inhibition, equivalent to a 1.00 g/dl increase in Hgb levels, was not associated (at P < 0.05) with increased odds of CAD; odd ratio (OR) [95% confidence intervals (CI)] = 1.06 (0.84, 1.35), MI [OR (95% CI) = 1.02 (0.79, 1.33)] or stroke [OR (95% CI) = 0.91 (0.66, 1.24)]. PheWAS revealed associations with blood related phenotypes consistent with EGLN's role, relevant kidney- and liver-related biomarkers like estimated glomerular filtration rate and microalbuminuria, and non-alcoholic fatty liver disease (Bonferroni-adjusted P < 5.42E-05) but these were not clinically meaningful. These findings suggest that long-term alterations in Hgb through PHD inhibition are unlikely to substantially increase cardiovascular disease risk; using large disease genome-wide association study data, we could exclude ORs of 1.35 for cardiovascular risk with a 1.00 g/dl increase in Hgb.


Asunto(s)
Enfermedades Cardiovasculares , Accidente Cerebrovascular , Humanos , Enfermedades Cardiovasculares/genética , Estudio de Asociación del Genoma Completo , Factores de Riesgo , Prolil Hidroxilasas/genética , Predisposición Genética a la Enfermedad , Factores de Riesgo de Enfermedad Cardiaca , Accidente Cerebrovascular/genética , Análisis de la Aleatorización Mendeliana
2.
Am J Hum Genet ; 109(9): 1638-1652, 2022 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-36055212

RESUMEN

Hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs) are currently under clinical development for treating anemia in chronic kidney disease (CKD), but it is important to monitor their cardiovascular safety. Genetic variants can be used as predictors to help inform the potential risk of adverse effects associated with drug treatments. We therefore aimed to use human genetics to help assess the risk of adverse cardiovascular events associated with therapeutically altered EPO levels to help inform clinical trials studying the safety of HIF-PHIs. By performing a genome-wide association meta-analysis of EPO (n = 6,127), we identified a cis-EPO variant (rs1617640) lying in the EPO promoter region. We validated this variant as most likely causal in controlling EPO levels by using genetic and functional approaches, including single-base gene editing. Using this variant as a partial predictor for therapeutic modulation of EPO and large genome-wide association data in Mendelian randomization tests, we found no evidence (at p < 0.05) that genetically predicted long-term rises in endogenous EPO, equivalent to a 2.2-unit increase, increased risk of coronary artery disease (CAD, OR [95% CI] = 1.01 [0.93, 1.07]), myocardial infarction (MI, OR [95% CI] = 0.99 [0.87, 1.15]), or stroke (OR [95% CI] = 0.97 [0.87, 1.07]). We could exclude increased odds of 1.15 for cardiovascular disease for a 2.2-unit EPO increase. A combination of genetic and functional studies provides a powerful approach to investigate the potential therapeutic profile of EPO-increasing therapies for treating anemia in CKD.


Asunto(s)
Anemia , Enfermedad de la Arteria Coronaria , Infarto del Miocardio , Insuficiencia Renal Crónica , Anemia/tratamiento farmacológico , Anemia/genética , Enfermedad de la Arteria Coronaria/genética , Estudio de Asociación del Genoma Completo , Humanos , Análisis de la Aleatorización Mendeliana , Infarto del Miocardio/genética , Insuficiencia Renal Crónica/genética
3.
Chem Rev ; 121(7): 3627-3700, 2021 04 14.
Artículo en Inglés | MEDLINE | ID: mdl-33645985

RESUMEN

Nanocrystals (NCs) are one of the few nanotechnologies to have attained mass market applications with their use as light sources for displays. This success relies on Cd- and In-based wide bandgap materials. NCs are likely to be employed in more applications as they provide a versatile platform for optoelectronics, specifically, infrared optoelectronics. The existing material technologies in this range of wavelengths are generally not cost-effective, which limits the spread of technologies beyond a few niche domains, such as defense and astronomy. Among the potential candidates to address the infrared window, mercury chalcogenide (HgX) NCs exhibit the highest potential in terms of performance. In this review, we discuss how material developments have facilitated device enhancements. Because these materials are mainly used for their infrared optical features, we first review the strategies for their colloidal growth and their specific electronic structure. The review is organized considering three main device-related applications: light emission, electronic transport, and infrared photodetection.

4.
Kidney Int ; 102(3): 624-639, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35716955

RESUMEN

Estimated glomerular filtration rate (eGFR) reflects kidney function. Progressive eGFR-decline can lead to kidney failure, necessitating dialysis or transplantation. Hundreds of loci from genome-wide association studies (GWAS) for eGFR help explain population cross section variability. Since the contribution of these or other loci to eGFR-decline remains largely unknown, we derived GWAS for annual eGFR-decline and meta-analyzed 62 longitudinal studies with eGFR assessed twice over time in all 343,339 individuals and in high-risk groups. We also explored different covariate adjustment. Twelve genome-wide significant independent variants for eGFR-decline unadjusted or adjusted for eGFR-baseline (11 novel, one known for this phenotype), including nine variants robustly associated across models were identified. All loci for eGFR-decline were known for cross-sectional eGFR and thus distinguished a subgroup of eGFR loci. Seven of the nine variants showed variant-by-age interaction on eGFR cross section (further about 350,000 individuals), which linked genetic associations for eGFR-decline with age-dependency of genetic cross-section associations. Clinically important were two to four-fold greater genetic effects on eGFR-decline in high-risk subgroups. Five variants associated also with chronic kidney disease progression mapped to genes with functional in-silico evidence (UMOD, SPATA7, GALNTL5, TPPP). An unfavorable versus favorable nine-variant genetic profile showed increased risk odds ratios of 1.35 for kidney failure (95% confidence intervals 1.03-1.77) and 1.27 for acute kidney injury (95% confidence intervals 1.08-1.50) in over 2000 cases each, with matched controls). Thus, we provide a large data resource, genetic loci, and prioritized genes for kidney function decline, which help inform drug development pipelines revealing important insights into the age-dependency of kidney function genetics.


Asunto(s)
N-Acetilgalactosaminiltransferasas , Insuficiencia Renal Crónica , Insuficiencia Renal , Estudios Transversales , Sitios Genéticos , Estudio de Asociación del Genoma Completo , Tasa de Filtración Glomerular/genética , Humanos , Riñón , Estudios Longitudinales , N-Acetilgalactosaminiltransferasas/genética , Insuficiencia Renal/genética
5.
Am J Hum Genet ; 104(1): 112-138, 2019 01 03.
Artículo en Inglés | MEDLINE | ID: mdl-30595373

RESUMEN

Mitochondria (MT), the major site of cellular energy production, are under dual genetic control by 37 mitochondrial DNA (mtDNA) genes and numerous nuclear genes (MT-nDNA). In the CHARGEmtDNA+ Consortium, we studied genetic associations of mtDNA and MT-nDNA associations with body mass index (BMI), waist-hip-ratio (WHR), glucose, insulin, HOMA-B, HOMA-IR, and HbA1c. This 45-cohort collaboration comprised 70,775 (insulin) to 170,202 (BMI) pan-ancestry individuals. Validation and imputation of mtDNA variants was followed by single-variant and gene-based association testing. We report two significant common variants, one in MT-ATP6 associated (p ≤ 5E-04) with WHR and one in the D-loop with glucose. Five rare variants in MT-ATP6, MT-ND5, and MT-ND6 associated with BMI, WHR, or insulin. Gene-based meta-analysis identified MT-ND3 associated with BMI (p ≤ 1E-03). We considered 2,282 MT-nDNA candidate gene associations compiled from online summary results for our traits (20 unique studies with 31 dataset consortia's genome-wide associations [GWASs]). Of these, 109 genes associated (p ≤ 1E-06) with at least 1 of our 7 traits. We assessed regulatory features of variants in the 109 genes, cis- and trans-gene expression regulation, and performed enrichment and protein-protein interactions analyses. Of the identified mtDNA and MT-nDNA genes, 79 associated with adipose measures, 49 with glucose/insulin, 13 with risk for type 2 diabetes, and 18 with cardiovascular disease, indicating for pleiotropic effects with health implications. Additionally, 21 genes related to cholesterol, suggesting additional important roles for the genes identified. Our results suggest that mtDNA and MT-nDNA genes and variants reported make important contributions to glucose and insulin metabolism, adipocyte regulation, diabetes, and cardiovascular disease.


Asunto(s)
ADN Mitocondrial/genética , Genes Mitocondriales/genética , Variación Genética/genética , Metabolismo/genética , Mitocondrias/genética , Mitocondrias/metabolismo , Adipocitos/metabolismo , Índice de Masa Corporal , Enfermedades Cardiovasculares/genética , Enfermedades Cardiovasculares/metabolismo , Estudios de Cohortes , Diabetes Mellitus/genética , Diabetes Mellitus/metabolismo , Glucosa/metabolismo , Hemoglobina Glucada/metabolismo , Humanos , Insulina/metabolismo , Sitios de Carácter Cuantitativo , Relación Cintura-Cadera
6.
Nano Lett ; 21(15): 6671-6677, 2021 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-34339191

RESUMEN

Nanocrystals (NCs) have gained considerable attention for their broadly tunable absorption from the UV to the THz range. Nevertheless, their optical features suffer from a lack of tunability once integrated into optoelectronic devices. Here, we show that bias tunable aspectral response is obtained by coupling a HgTe NC array with a plasmonic resonator. Up to 15 meV blueshift can be achieved from a 3 µm absorbing wavelength structure under a 3 V bias voltage when the NC exciton is coupled with a mode of the resonator. We demonstrate that the blueshift arises from the interplay between hopping transport and inhomogeneous absorption due to the presence of the photonic structure. The observed tunable spectral response is qualitatively reproduced in simulation by introducing a bias-dependent diffusion length in the charge transport. This work expands the realm of existing NC-based devices and paves the way toward light modulators.

7.
Nano Lett ; 21(10): 4145-4151, 2021 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-33956449

RESUMEN

HgTe nanocrystals (NCs) enable broadly tunable infrared absorption, now commonly used to design light sensors. This material tends to grow under multipodic shapes and does not present well-defined size distributions. Such point generates traps and reduces the particle packing, leading to a reduced mobility. It is thus highly desirable to comprehensively explore the effect of the shape on their performance. Here, we show, using a combination of electron tomography and tight binding simulations, that the charge dissociation is strong within HgTe NCs, but poorly shape dependent. Then, we design a dual-gate field-effect-transistor made of tripod HgTe NCs and use it to generate a planar p-n junction, offering more tunability than its vertical geometry counterpart. Interestingly, the performance of the tripods is higher than sphere ones, and this can be correlated with a stronger Te excess in the case of sphere shapes which is responsible for a higher hole trap density.

8.
Kidney Int ; 99(4): 926-939, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33137338

RESUMEN

Rapid decline of glomerular filtration rate estimated from creatinine (eGFRcrea) is associated with severe clinical endpoints. In contrast to cross-sectionally assessed eGFRcrea, the genetic basis for rapid eGFRcrea decline is largely unknown. To help define this, we meta-analyzed 42 genome-wide association studies from the Chronic Kidney Diseases Genetics Consortium and United Kingdom Biobank to identify genetic loci for rapid eGFRcrea decline. Two definitions of eGFRcrea decline were used: 3 mL/min/1.73m2/year or more ("Rapid3"; encompassing 34,874 cases, 107,090 controls) and eGFRcrea decline 25% or more and eGFRcrea under 60 mL/min/1.73m2 at follow-up among those with eGFRcrea 60 mL/min/1.73m2 or more at baseline ("CKDi25"; encompassing 19,901 cases, 175,244 controls). Seven independent variants were identified across six loci for Rapid3 and/or CKDi25: consisting of five variants at four loci with genome-wide significance (near UMOD-PDILT (2), PRKAG2, WDR72, OR2S2) and two variants among 265 known eGFRcrea variants (near GATM, LARP4B). All these loci were novel for Rapid3 and/or CKDi25 and our bioinformatic follow-up prioritized variants and genes underneath these loci. The OR2S2 locus is novel for any eGFRcrea trait including interesting candidates. For the five genome-wide significant lead variants, we found supporting effects for annual change in blood urea nitrogen or cystatin-based eGFR, but not for GATM or LARP4B. Individuals at high compared to those at low genetic risk (8-14 vs. 0-5 adverse alleles) had a 1.20-fold increased risk of acute kidney injury (95% confidence interval 1.08-1.33). Thus, our identified loci for rapid kidney function decline may help prioritize therapeutic targets and identify mechanisms and individuals at risk for sustained deterioration of kidney function.


Asunto(s)
Estudio de Asociación del Genoma Completo , Riñón , Proteínas Quinasas Activadas por AMP , Creatinina , Tasa de Filtración Glomerular/genética , Humanos , Proteína Disulfuro Isomerasas , Reino Unido
9.
Nano Lett ; 20(8): 6185-6190, 2020 08 12.
Artículo en Inglés | MEDLINE | ID: mdl-32662652

RESUMEN

Mercury telluride (HgTe) nanocrystals are among the most versatile infrared (IR) materials with the absorption of lowest energy optical absorption which can be tuned from the visible to the terahertz range. Therefore, they have been extensively considered as near IR emitters and as absorbers for low-cost IR detectors. However, the electroluminescence of HgTe remains poorly investigated despite its ability to go toward longer wavelengths compared to traditional lead sulfide (PbS). Here, we demonstrate a light-emitting diode (LED) based on an indium tin oxide (ITO)/zinc oxide (ZnO)/ZnO-HgTe/PbS/gold-stacked structure, where the emitting layer consists of a ZnO/HgTe bulk heterojunction which drives the charge balance in the system. This LED has low turn-on voltage, long lifetime, and high brightness. Finally, we conduct short wavelength infrared (SWIR) active imaging, where illumination is obtained from a HgTe NC-based LED, and demonstrate moisture detection.


Asunto(s)
Nanopartículas , Óxido de Zinc , Oro , Rayos Infrarrojos , Iluminación
10.
Nano Lett ; 20(5): 3999-4006, 2020 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-32283029

RESUMEN

To date, defect-tolerance electronic structure of lead halide perovskite nanocrystals is limited to an optical feature in the visible range. Here, we demonstrate that IR sensitization of formamidinium lead iodine (FAPI) nanocrystal array can be obtained by its doping with PbS nanocrystals. In this hybrid array, absorption comes from the PbS nanocrystals while transport is driven by the perovskite which reduces the dark current compared to pristine PbS. In addition, we fabricate a field-effect transistor using a high capacitance ionic glass made of hybrid FAPI/PbS nanocrystal arrays. We show that the hybrid material has an n-type nature with an electron mobility of 2 × 10-3 cm2 V-1 s-1. However, the dark current reduction is mostly balanced by a loss of absorption. To overcome this limitation, we couple the FAPI/PbS hybrid to a guided mode resonator that can enhance the infrared light absorption.

11.
Am J Hum Genet ; 100(1): 51-63, 2017 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-28017375

RESUMEN

Genome-wide association studies (GWASs) have identified loci for erythrocyte traits in primarily European ancestry populations. We conducted GWAS meta-analyses of six erythrocyte traits in 71,638 individuals from European, East Asian, and African ancestries using a Bayesian approach to account for heterogeneity in allelic effects and variation in the structure of linkage disequilibrium between ethnicities. We identified seven loci for erythrocyte traits including a locus (RBPMS/GTF2E2) associated with mean corpuscular hemoglobin and mean corpuscular volume. Statistical fine-mapping at this locus pointed to RBPMS at this locus and excluded nearby GTF2E2. Using zebrafish morpholino to evaluate loss of function, we observed a strong in vivo erythropoietic effect for RBPMS but not for GTF2E2, supporting the statistical fine-mapping at this locus and demonstrating that RBPMS is a regulator of erythropoiesis. Our findings show the utility of trans-ethnic GWASs for discovery and characterization of genetic loci influencing hematologic traits.


Asunto(s)
Eritrocitos/metabolismo , Eritropoyesis/genética , Proteínas de Unión al ARN/genética , Grupos Raciales/genética , África/etnología , Alelos , Animales , Teorema de Bayes , Etnicidad/genética , Europa (Continente)/etnología , Asia Oriental/etnología , Femenino , Estudio de Asociación del Genoma Completo , Humanos , Desequilibrio de Ligamiento , Masculino , Pez Cebra/genética
12.
Arterioscler Thromb Vasc Biol ; 39(6): 1182-1190, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31070471

RESUMEN

Objective- Inflammation is a causal risk factor for cardiovascular disease (CVD). sPLA2-IIA (group IIA secretory phospholipase A2) plays an integral role in regulating vascular inflammation. Although studies investigated sPLA2-IIA in secondary prevention, we prospectively evaluated sPLA2-IIA mass and genetic variants with CVD events in a primary prevention population with chronic inflammation. Approach and Results- The JUPITER trial (Justification for the Use of Statins in Prevention: An Intervention Trial Evaluating Rosuvastatin) randomized participants with LDL (low-density lipoprotein) <130 mg/dL and hsCRP (high-sensitivity C-reactive protein) ≥2 mg/L to high-intensity rosuvastatin versus placebo. Baseline and 1-year plasma sPLA2-IIA mass was measured (N=11 269 baseline; N=9620 1 year). We also identified genetic variants influencing sPLA2-IIA using genome-wide association and examined them with CVD. Three hundred thirteen incident CVD events occurred during follow-up. Baseline sPLA2-IIA mass (median, 25th-75th percentile: 3.81, 2.49-6.03 ng/mL) was associated with increased risk of CVD: risk factor-adjusted hazard ratio (95% CI; P) per SD increment: 1.22 (1.08-1.38; P=0.002). This remained significant (1.18; 1.04-1.35; P=0.01) after incrementally adjusting for hsCRP. Similar estimates were observed in rosuvastatin and placebo groups ( P treatment interaction>0.05). The rs11573156C variant in PLA2G2A (encoding sPLA2-IIA) had the strongest effect on sPLA2-II: median (25th-75th percentile, ng/mL) for CC and GG genotypes: 2.79 (1.97-4.01) and 7.38 (5.38-10.19), respectively; and had nonsignificant trend for higher CVD risk (hazard ratio, 1.11; 95% CI, 0.89-1.38; P=0.34). Conclusions- In the JUPITER population recruited on chronic inflammation, sPLA2-IIA mass was associated with CVD risk relating to vascular inflammation not fully reflected by hsCRP. Additional studies, including larger functional genetic and clinical studies, are needed to determine whether sPLA2-IIA may be a potential pharmacological target for primary prevention of CVD. Clinical Trial Registration- URL: http://www.clinicaltrials.gov . Unique identifier: NCT00239681.


Asunto(s)
Enfermedades Cardiovasculares/enzimología , Dislipidemias/enzimología , Fosfolipasas A2 Grupo II/sangre , Inflamación/enzimología , Anciano , Antiinflamatorios/uso terapéutico , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/genética , Enfermedades Cardiovasculares/prevención & control , Método Doble Ciego , Dislipidemias/tratamiento farmacológico , Dislipidemias/epidemiología , Dislipidemias/genética , Femenino , Predisposición Genética a la Enfermedad , Fosfolipasas A2 Grupo II/genética , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Incidencia , Inflamación/tratamiento farmacológico , Inflamación/epidemiología , Inflamación/genética , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Prevención Primaria , Estudios Prospectivos , Medición de Riesgo , Factores de Riesgo , Rosuvastatina Cálcica/uso terapéutico , Factores de Tiempo , Resultado del Tratamiento
13.
PLoS Genet ; 13(6): e1006812, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28614350

RESUMEN

Phenotypic variance heterogeneity across genotypes at a single nucleotide polymorphism (SNP) may reflect underlying gene-environment (G×E) or gene-gene interactions. We modeled variance heterogeneity for blood lipids and BMI in up to 44,211 participants and investigated relationships between variance effects (Pv), G×E interaction effects (with smoking and physical activity), and marginal genetic effects (Pm). Correlations between Pv and Pm were stronger for SNPs with established marginal effects (Spearman's ρ = 0.401 for triglycerides, and ρ = 0.236 for BMI) compared to all SNPs. When Pv and Pm were compared for all pruned SNPs, only BMI was statistically significant (Spearman's ρ = 0.010). Overall, SNPs with established marginal effects were overrepresented in the nominally significant part of the Pv distribution (Pbinomial <0.05). SNPs from the top 1% of the Pm distribution for BMI had more significant Pv values (PMann-Whitney = 1.46×10-5), and the odds ratio of SNPs with nominally significant (<0.05) Pm and Pv was 1.33 (95% CI: 1.12, 1.57) for BMI. Moreover, BMI SNPs with nominally significant G×E interaction P-values (Pint<0.05) were enriched with nominally significant Pv values (Pbinomial = 8.63×10-9 and 8.52×10-7 for SNP × smoking and SNP × physical activity, respectively). We conclude that some loci with strong marginal effects may be good candidates for G×E, and variance-based prioritization can be used to identify them.


Asunto(s)
HDL-Colesterol/genética , LDL-Colesterol/genética , Interacción Gen-Ambiente , Obesidad/genética , Índice de Masa Corporal , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Femenino , Heterogeneidad Genética , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Genotipo , Humanos , Masculino , Obesidad/sangre , Polimorfismo de Nucleótido Simple , Sitios de Carácter Cuantitativo/genética , Factores de Riesgo , Fumar/genética , Población Blanca/genética
15.
PLoS Genet ; 13(4): e1006528, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28448500

RESUMEN

Physical activity (PA) may modify the genetic effects that give rise to increased risk of obesity. To identify adiposity loci whose effects are modified by PA, we performed genome-wide interaction meta-analyses of BMI and BMI-adjusted waist circumference and waist-hip ratio from up to 200,452 adults of European (n = 180,423) or other ancestry (n = 20,029). We standardized PA by categorizing it into a dichotomous variable where, on average, 23% of participants were categorized as inactive and 77% as physically active. While we replicate the interaction with PA for the strongest known obesity-risk locus in the FTO gene, of which the effect is attenuated by ~30% in physically active individuals compared to inactive individuals, we do not identify additional loci that are sensitive to PA. In additional genome-wide meta-analyses adjusting for PA and interaction with PA, we identify 11 novel adiposity loci, suggesting that accounting for PA or other environmental factors that contribute to variation in adiposity may facilitate gene discovery.


Asunto(s)
Adiposidad/genética , Dioxigenasa FTO Dependiente de Alfa-Cetoglutarato/genética , Ejercicio Físico , Obesidad/genética , Adiposidad/fisiología , Índice de Masa Corporal , Epigenómica , Femenino , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Genotipo , Humanos , Masculino , Obesidad/fisiopatología , Circunferencia de la Cintura , Relación Cintura-Cadera
16.
Nano Lett ; 19(6): 3981-3986, 2019 06 12.
Artículo en Inglés | MEDLINE | ID: mdl-31059646

RESUMEN

The gating of nanocrystal films is currently driven by two approaches: either the use of a dielectric such as SiO2 or the use of electrolyte. SiO2 allows fast bias sweeping over a broad range of temperatures but requires a large operating bias. Electrolytes, thanks to large capacitances, lead to the significant reduction of operating bias but are limited to slow and quasi-room-temperature operation. None of these operating conditions are optimal for narrow-band-gap nanocrystal-based phototransistors, for which the necessary large-capacitance gate has to be combined with low-temperature operation. Here, we explore the use of a LaF3 ionic glass as a high-capacitance gating alternative. We demonstrate for the first time the use of such ionic glasses to gate thin films made of HgTe and PbS nanocrystals. This gating strategy allows operation in the 180 to 300 K range of temperatures with capacitance as high as 1 µF·cm-2. We unveil the unique property of ionic glass gate to enable the unprecedented tunability of both magnitude and dynamics of the photocurrent thanks to high charge-doping capability within an operating temperature window relevant for infrared photodetection. We demonstrate that by carefully choosing the operating gate bias, the signal-to-noise ratio can be improved by a factor of 100 and the time response accelerated by a factor of 6. Moreover, the good transparency of LaF3 substrate allows back-side illumination in the infrared range, which is highly valuable for the design of phototransistors.

17.
Int J Obes (Lond) ; 43(3): 457-467, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30232418

RESUMEN

OBJECTIVE: Indices of body fat distribution are heritable, but few genetic signals have been reported from genome-wide association studies (GWAS) of computed tomography (CT) imaging measurements of body fat distribution. We aimed to identify genes associated with adiposity traits and the key drivers that are central to adipose regulatory networks. SUBJECTS: We analyzed gene transcript expression data in blood from participants in the Framingham Heart Study, a large community-based cohort (n up to 4303), as well as implemented an integrative analysis of these data and existing biological information. RESULTS: Our association analyses identified unique and common gene expression signatures across several adiposity traits, including body mass index, waist-hip ratio, waist circumference, and CT-measured indices, including volume and quality of visceral and subcutaneous adipose tissues. We identified six enriched KEGG pathways and two co-expression modules for further exploration of adipose regulatory networks. The integrative analysis revealed four gene sets (Apoptosis, p53 signaling pathway, Proteasome, Ubiquitin-mediated proteolysis) and two co-expression modules with significant genetic variants and 94 key drivers/genes whose local networks were enriched with adiposity-associated genes, suggesting that these enriched pathways or modules have genetic effects on adiposity. Most identified key driver genes are involved in essential biological processes such as controlling cell cycle, DNA repair, and degradation of regulatory proteins are cancer related. CONCLUSIONS: Our integrative analysis of genetic, transcriptional, and biological information provides a list of compelling candidates for further follow-up functional studies to uncover the biological mechanisms underlying obesity. These candidates highlight the value of examining CT-derived and central adiposity traits.


Asunto(s)
Perfilación de la Expresión Génica/métodos , Estudio de Asociación del Genoma Completo/métodos , Obesidad , Tejido Adiposo Blanco/diagnóstico por imagen , Adulto , Pesos y Medidas Corporales , Femenino , Redes Reguladoras de Genes/genética , Humanos , Estudios Longitudinales , Masculino , Obesidad/diagnóstico por imagen , Obesidad/epidemiología , Obesidad/genética , Obesidad/fisiopatología , Tomografía Computarizada por Rayos X , Transcriptoma/genética
18.
PLoS Med ; 14(9): e1002383, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28898252

RESUMEN

BACKGROUND: Glycated hemoglobin (HbA1c) is used to diagnose type 2 diabetes (T2D) and assess glycemic control in patients with diabetes. Previous genome-wide association studies (GWAS) have identified 18 HbA1c-associated genetic variants. These variants proved to be classifiable by their likely biological action as erythrocytic (also associated with erythrocyte traits) or glycemic (associated with other glucose-related traits). In this study, we tested the hypotheses that, in a very large scale GWAS, we would identify more genetic variants associated with HbA1c and that HbA1c variants implicated in erythrocytic biology would affect the diagnostic accuracy of HbA1c. We therefore expanded the number of HbA1c-associated loci and tested the effect of genetic risk-scores comprised of erythrocytic or glycemic variants on incident diabetes prediction and on prevalent diabetes screening performance. Throughout this multiancestry study, we kept a focus on interancestry differences in HbA1c genetics performance that might influence race-ancestry differences in health outcomes. METHODS & FINDINGS: Using genome-wide association meta-analyses in up to 159,940 individuals from 82 cohorts of European, African, East Asian, and South Asian ancestry, we identified 60 common genetic variants associated with HbA1c. We classified variants as implicated in glycemic, erythrocytic, or unclassified biology and tested whether additive genetic scores of erythrocytic variants (GS-E) or glycemic variants (GS-G) were associated with higher T2D incidence in multiethnic longitudinal cohorts (N = 33,241). Nineteen glycemic and 22 erythrocytic variants were associated with HbA1c at genome-wide significance. GS-G was associated with higher T2D risk (incidence OR = 1.05, 95% CI 1.04-1.06, per HbA1c-raising allele, p = 3 × 10-29); whereas GS-E was not (OR = 1.00, 95% CI 0.99-1.01, p = 0.60). In Europeans and Asians, erythrocytic variants in aggregate had only modest effects on the diagnostic accuracy of HbA1c. Yet, in African Americans, the X-linked G6PD G202A variant (T-allele frequency 11%) was associated with an absolute decrease in HbA1c of 0.81%-units (95% CI 0.66-0.96) per allele in hemizygous men, and 0.68%-units (95% CI 0.38-0.97) in homozygous women. The G6PD variant may cause approximately 2% (N = 0.65 million, 95% CI 0.55-0.74) of African American adults with T2D to remain undiagnosed when screened with HbA1c. Limitations include the smaller sample sizes for non-European ancestries and the inability to classify approximately one-third of the variants. Further studies in large multiethnic cohorts with HbA1c, glycemic, and erythrocytic traits are required to better determine the biological action of the unclassified variants. CONCLUSIONS: As G6PD deficiency can be clinically silent until illness strikes, we recommend investigation of the possible benefits of screening for the G6PD genotype along with using HbA1c to diagnose T2D in populations of African ancestry or groups where G6PD deficiency is common. Screening with direct glucose measurements, or genetically-informed HbA1c diagnostic thresholds in people with G6PD deficiency, may be required to avoid missed or delayed diagnoses.


Asunto(s)
Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/genética , Variación Genética , Estudio de Asociación del Genoma Completo , Hemoglobina Glucada/genética , Diabetes Mellitus Tipo 2/epidemiología , Hemoglobina Glucada/metabolismo , Humanos , Fenotipo , Riesgo
19.
BMC Nephrol ; 18(1): 32, 2017 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-28103844

RESUMEN

BACKGROUND: We developed a genetic risk score (GRS) and examined whether the GRS may predict incident stage 3 chronic kidney disease (CKD) independent of common clinical risk factors. METHOD: The present study included 2,698 individuals who attended the 15th (1977 to 1979) and the 24th exams (1995 to 1998) in the Framingham Original cohort or the 6th (1995 to 1998) and the 8th exams (2005 to 2008) in the Framingham Offspring cohort. A weighted GRS was constructed combining 53 single nucleotide polymorphisms (SNPs) associated with lower creatinine-based estimated glomerular filtration rate (eGFR). Stage 3 CKD was defined as eGFR <60 mL/min/1.73 m2, and incident cases were identified at follow-up after excluding prevalent cases at baseline. RESULTS: A total of 292 incident cases and 2,406 non-cases were identified over, on average, 11 years of follow-up. After adjustment for sex, age, cohort, baseline eGFR, hypertension, diabetes, and dipstick proteinuria, the odds ratio of incident stage 3 CKD was 1.37 (95%CI: 1.02-1.83) per 10 alleles of the GRS (P = 0.04). There was no statistically significant difference between the C-statistic without and with inclusion of the GRS (0.783 and 0.785, respectively; P = 0.39). CONCLUSIONS: A GRS developed based on 53 SNPs associated with reduced eGFR was prospectively associated with incident stage 3 CKD. However, this score did not substantially improve discrimination of stage 3 CKD beyond the common clinical risk factors.


Asunto(s)
Predisposición Genética a la Enfermedad/epidemiología , Predisposición Genética a la Enfermedad/genética , Pruebas Genéticas/métodos , Polimorfismo de Nucleótido Simple/genética , Modelos de Riesgos Proporcionales , Insuficiencia Renal Crónica/epidemiología , Insuficiencia Renal Crónica/genética , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Marcadores Genéticos/genética , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Insuficiencia Renal Crónica/diagnóstico , Reproducibilidad de los Resultados , Medición de Riesgo/métodos , Sensibilidad y Especificidad , Estados Unidos/epidemiología
20.
Hum Mol Genet ; 23(25): 6961-72, 2014 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-25104851

RESUMEN

FTO is the strongest known genetic susceptibility locus for obesity. Experimental studies in animals suggest the potential roles of FTO in regulating food intake. The interactive relation among FTO variants, dietary intake and body mass index (BMI) is complex and results from previous often small-scale studies in humans are highly inconsistent. We performed large-scale analyses based on data from 177,330 adults (154 439 Whites, 5776 African Americans and 17 115 Asians) from 40 studies to examine: (i) the association between the FTO-rs9939609 variant (or a proxy single-nucleotide polymorphism) and total energy and macronutrient intake and (ii) the interaction between the FTO variant and dietary intake on BMI. The minor allele (A-allele) of the FTO-rs9939609 variant was associated with higher BMI in Whites (effect per allele = 0.34 [0.31, 0.37] kg/m(2), P = 1.9 × 10(-105)), and all participants (0.30 [0.30, 0.35] kg/m(2), P = 3.6 × 10(-107)). The BMI-increasing allele of the FTO variant showed a significant association with higher dietary protein intake (effect per allele = 0.08 [0.06, 0.10] %, P = 2.4 × 10(-16)), and relative weak associations with lower total energy intake (-6.4 [-10.1, -2.6] kcal/day, P = 0.001) and lower dietary carbohydrate intake (-0.07 [-0.11, -0.02] %, P = 0.004). The associations with protein (P = 7.5 × 10(-9)) and total energy (P = 0.002) were attenuated but remained significant after adjustment for BMI. We did not find significant interactions between the FTO variant and dietary intake of total energy, protein, carbohydrate or fat on BMI. Our findings suggest a positive association between the BMI-increasing allele of FTO variant and higher dietary protein intake and offer insight into potential link between FTO, dietary protein intake and adiposity.


Asunto(s)
Proteínas en la Dieta/administración & dosificación , Ingestión de Energía/genética , Obesidad/etnología , Obesidad/genética , Polimorfismo de Nucleótido Simple , Proteínas/genética , Adulto , Negro o Afroamericano , Anciano , Alelos , Dioxigenasa FTO Dependiente de Alfa-Cetoglutarato , Pueblo Asiatico , Índice de Masa Corporal , Carbohidratos de la Dieta/administración & dosificación , Grasas de la Dieta/administración & dosificación , Femenino , Frecuencia de los Genes , Humanos , Masculino , Persona de Mediana Edad , Obesidad/metabolismo , Obesidad/patología , Población Blanca
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