Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 97
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
N Engl J Med ; 387(15): 1385-1394, 2022 10 13.
Artículo en Inglés | MEDLINE | ID: mdl-36027560

RESUMEN

BACKGROUND: Limited data suggest a benefit of population-based screening for cardiovascular disease with respect to the risk of death. METHODS: We performed a population-based, parallel-group, randomized, controlled trial involving men 65 to 74 years of age living in 15 Danish municipalities. The participants were randomly assigned in a 1:2 ratio to undergo screening (the invited group) or not to undergo screening (the control group) for subclinical cardiovascular disease. Randomization was based on computer-generated random numbers and stratified according to municipality. Only the control group was unaware of the trial-group assignments. Screening included noncontrast electrocardiography-gated computed tomography to determine the coronary-artery calcium score and to detect aneurysms and atrial fibrillation, ankle-brachial blood-pressure measurements to detect peripheral artery disease and hypertension, and a blood sample to detect diabetes mellitus and hypercholesterolemia. The primary outcome was death from any cause. RESULTS: A total of 46,611 participants underwent randomization. After exclusion of 85 men who had died or emigrated before being invited to undergo screening, there were 16,736 men in the invited group and 29,790 men in the control group; 10,471 of the men in the invited group underwent screening (62.6%). In intention-to-treat analyses, after a median follow-up of 5.6 years, 2106 men (12.6%) in the invited group and 3915 men (13.1%) in the control group had died (hazard ratio, 0.95; 95% confidence interval [CI], 0.90 to 1.00; P = 0.06). The hazard ratio for stroke in the invited group, as compared with the control group, was 0.93 (95% CI, 0.86 to 0.99); for myocardial infarction, 0.91 (95% CI, 0.81 to 1.03); for aortic dissection, 0.95 (95% CI, 0.61 to 1.49); and for aortic rupture, 0.81 (95% CI, 0.49 to 1.35). There were no significant between-group differences in safety outcomes. CONCLUSIONS: After more than 5 years, the invitation to undergo comprehensive cardiovascular screening did not significantly reduce the incidence of death from any cause among men 65 to 74 years of age. (Funded by the Southern Region of Denmark and others; DANCAVAS ISRCTN Registry number, ISRCTN12157806.).


Asunto(s)
Enfermedades Cardiovasculares , Tamizaje Masivo , Humanos , Masculino , Calcio/análisis , Dinamarca/epidemiología , Incidencia , Tamizaje Masivo/métodos , Enfermedad Arterial Periférica/diagnóstico , Enfermedad Arterial Periférica/epidemiología , Anciano , Técnicas de Imagen Sincronizada Cardíacas , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/epidemiología
2.
Circulation ; 145(6): 427-436, 2022 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-34882430

RESUMEN

BACKGROUND: DANISH (The Danish Study to Assess the Efficacy of Implantable Cardioverter Defibrillators [ICDs] in Patients With Nonischemic Systolic Heart Failure on Mortality) found that primary-prevention ICD implantation was not associated with an overall survival benefit in patients with nonischemic systolic heart failure during a median follow-up of 5.6 years, although there was a beneficial effect on all-cause mortality in patients ≤70 years. This study presents an additional 4 years of follow-up data from DANISH. METHODS: In DANISH, 556 patients with nonischemic systolic heart failure were randomized to receive an ICD and 560 to receive usual clinical care and followed until June 30, 2016. In this long-term follow-up study, patients were followed until May 18, 2020. Analyses were conducted for the overall population and according to age (≤70 and >70 years). RESULTS: During a median follow-up of 9.5 years (25th-75th percentile, 7.9-10.9 years), 208/556 patients (37%) in the ICD group and 226/560 patients (40%) in the control group died. Compared with the control group, the ICD group did not have significantly lower all-cause mortality (hazard ratio [HR] 0.89, [95% CI, 0.74-1.08]; P = 0.24). In patients ≤70 years (n = 829), all-cause mortality was lower in the ICD group than the control group (117/389 [30%] versus 158/440 [36%]; HR, 0.78 [95% CI, 0.61-0.99]; P = 0.04), whereas in patients >70 years (n = 287), all-cause mortality was not significantly different between the ICD and control group (91/167 [54%] versus 68/120 [57%]; HR, 0.92 [95% CI, 0.67-1.28]; P = 0.75). Cardiovascular death showed similar trends (overall, 147/556 [26%] versus 164/560 [29%]; HR, 0.87 [95% CI, 0.70-1.09]; P = 0.20; ≤70 years, 87/389 [22%] versus 122/440 [28%]; HR, 0.75 [95% CI, 0.57-0.98]; P = 0.04; >70 years, 60/167 [36%] versus 42/120 [35%]; HR, 0.97 [95% CI, 0.65-1.45]; P = 0.91). The ICD group had a significantly lower incidence of sudden cardiovascular death in the overall population (35/556 [6%] versus 57/560 [10%]; HR, 0.60 [95% CI, 0.40-0.92]; P = 0.02) and in patients ≤70 years (19/389 [5%] versus 49/440 [11%]; HR, 0.42 [95% CI, 0.24-0.71]; P = 0.0008), but not in patients >70 years (16/167 [10%] versus 8/120 [7%]; HR, 1.34 [95% CI, 0.56-3.19]; P = 0.39). CONCLUSIONS: During a median follow-up of 9.5 years, ICD implantation did not provide an overall survival benefit in patients with nonischemic systolic heart failure. In patients ≤70 years, ICD implantation was associated with a lower incidence of all-cause mortality, cardiovascular death, and sudden cardiovascular death. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT00542945.


Asunto(s)
Desfibriladores Implantables/normas , Insuficiencia Cardíaca Sistólica/epidemiología , Insuficiencia Cardíaca Sistólica/mortalidad , Anciano , Dinamarca , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Análisis de Supervivencia
3.
Eur Heart J ; 43(41): 4392-4402, 2022 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-36029019

RESUMEN

AIMS: A recent trial has shown that screening of men for cardiovascular disease (CVD) may reduce all-cause mortality. This study assesses the cost effectiveness of such screening vs. no screening from the perspective of European healthcare systems. METHODS AND RESULTS: Randomized controlled trial-based cost-effectiveness evaluation with a mean 5.7 years of follow-up. Screening was based on low-dose computed tomography to detect coronary artery calcification and aortic/iliac aneurysms, limb blood pressure measurement to detect peripheral artery disease and hypertension, telemetric assessment of the heart rhythm to detect atrial fibrillation, and measurements of the cholesterol and HgbA1c levels. Censoring-adjusted incremental costs, life years (LY), and quality-adjusted LY (QALY) were estimated and used for cost-effectiveness analysis. The incremental cost of screening for the entire health care sector was €207 [95% confidence interval (CI) -24; 438, P = 0.078] per invitee for which gains of 0.019 LY (95% CI -0.007; 0.045, P = 0.145) and 0.023 QALY (95% CI -0.001; 0.046, P = 0.051) were achieved. The corresponding incremental cost-effectiveness ratios were of €10 812 per LY and €9075 per QALY, which would be cost effective at probabilities of 0.73 and 0.83 for a willingness to pay of €20 000. Assessment of population heterogeneity showed that cost effectiveness could be more attractive for younger men without CVD at baseline. CONCLUSIONS: Comprehensive screening for CVD is overall cost effective at conventional thresholds for willingness to pay and also competitive to the cost effectiveness of common cancer screening programmes. The screening target group, however, needs to be settled.


Asunto(s)
Enfermedades Cardiovasculares , Masculino , Humanos , Análisis Costo-Beneficio , Enfermedades Cardiovasculares/prevención & control , Tamizaje Masivo/métodos , Años de Vida Ajustados por Calidad de Vida , Dinamarca/epidemiología
4.
Angew Chem Int Ed Engl ; 61(35): e202207137, 2022 08 26.
Artículo en Inglés | MEDLINE | ID: mdl-35718746

RESUMEN

The complexation of MgII with adenosine 5'-triphosphate (ATP) is omnipresent in biochemical energy conversion, but is difficult to interrogate directly. Here we use the spin- 1/2 ß-emitter 31 Mg to study MgII -ATP complexation in 1-ethyl-3-methylimidazolium acetate (EMIM-Ac) solutions using ß-radiation-detected nuclear magnetic resonance (ß-NMR). We demonstrate that (nuclear) spin-polarized 31 Mg, following ion-implantation from an accelerator beamline into EMIM-Ac, binds to ATP within its radioactive lifetime before depolarizing. The evolution of the spectra with solute concentration indicates that the implanted 31 Mg initially bind to the solvent acetate anions, whereafter they undergo dynamic exchange and form either a mono- (31 Mg-ATP) or di-nuclear (31 MgMg-ATP) complex. The chemical shift of 31 Mg-ATP is observed up-field of 31 MgMg-ATP, in accord with quantum chemical calculations. These observations constitute a crucial advance towards using ß-NMR to probe chemistry and biochemistry in solution.


Asunto(s)
Adenosina Trifosfato , Magnesio , Adenosina Trifosfato/química , Imidazoles , Espectroscopía de Resonancia Magnética/métodos
5.
N Engl J Med ; 375(13): 1221-30, 2016 09 29.
Artículo en Inglés | MEDLINE | ID: mdl-27571011

RESUMEN

BACKGROUND: The benefit of an implantable cardioverter-defibrillator (ICD) in patients with symptomatic systolic heart failure caused by coronary artery disease has been well documented. However, the evidence for a benefit of prophylactic ICDs in patients with systolic heart failure that is not due to coronary artery disease has been based primarily on subgroup analyses. The management of heart failure has improved since the landmark ICD trials, and many patients now receive cardiac resynchronization therapy (CRT). METHODS: In a randomized, controlled trial, 556 patients with symptomatic systolic heart failure (left ventricular ejection fraction, ≤35%) not caused by coronary artery disease were assigned to receive an ICD, and 560 patients were assigned to receive usual clinical care (control group). In both groups, 58% of the patients received CRT. The primary outcome of the trial was death from any cause. The secondary outcomes were sudden cardiac death and cardiovascular death. RESULTS: After a median follow-up period of 67.6 months, the primary outcome had occurred in 120 patients (21.6%) in the ICD group and in 131 patients (23.4%) in the control group (hazard ratio, 0.87; 95% confidence interval [CI], 0.68 to 1.12; P=0.28). Sudden cardiac death occurred in 24 patients (4.3%) in the ICD group and in 46 patients (8.2%) in the control group (hazard ratio, 0.50; 95% CI, 0.31 to 0.82; P=0.005). Device infection occurred in 27 patients (4.9%) in the ICD group and in 20 patients (3.6%) in the control group (P=0.29). CONCLUSIONS: In this trial, prophylactic ICD implantation in patients with symptomatic systolic heart failure not caused by coronary artery disease was not associated with a significantly lower long-term rate of death from any cause than was usual clinical care. (Funded by Medtronic and others; DANISH ClinicalTrials.gov number, NCT00542945 .).


Asunto(s)
Estimulación Cardíaca Artificial , Desfibriladores Implantables , Insuficiencia Cardíaca Sistólica/terapia , Anciano , Enfermedades Cardiovasculares/mortalidad , Muerte Súbita Cardíaca/epidemiología , Electrocardiografía , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Mortalidad , Volumen Sistólico
6.
Europace ; 21(6): 900-908, 2019 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-30796456

RESUMEN

AIM: The Danish Study to Assess the Efficacy of Implantable Cardioverter-Defibrillators (ICD) in Patients with Non-ischaemic Systolic Heart Failure (HF) on Mortality (DANISH) found no overall effect on all-cause mortality. The effect of ICD implantation on health-related quality of life (HRQoL) remains to be established as previous trials have demonstrated conflicting results. We investigated the impact of ICD implantation on HRQoL in patients with non-ischaemic systolic HF, a prespecified secondary endpoint in DANISH. METHODS AND RESULTS: In DANISH, a total of 1116 patients with non-ischaemic systolic HF were randomly assigned (1:1) to ICD implantation or usual clinical care (control). Patients completed disease-specific HRQoL as assessed by Minnesota Living with Heart Failure Questionnaire (MLHFQ; 0-105, high indicating worse). Changes in HRQoL 8 months after randomization were assessed with a mixed-effects model. At randomization, MLHFQ was completed by 935 (84%) patients (n = 472 in the ICD group and n = 463 in the control group) and was reassessed in 274 (58%) and 292 (63%) patients, respectively after 8 months for the primary analysis. Patients in the ICD group vs. the control group had similar improvements in MLHFQ after 8 months [least square mean -7.0 vs. -4.2 (P = 0.13)]. A clinically relevant improvement (decrease ≥5) in the MLHFQ overall score at 8 months was observed in 151 patients in the ICD group and 148 patients in the control group [55% vs. 51%, respectively (P = 0.25)]. CONCLUSION: Implantable cardioverter-defibrillator implantation in patients with non-ischaemic systolic HF did not significantly alter HRQoL compared with patients randomized to usual clinical care.


Asunto(s)
Desfibriladores Implantables , Insuficiencia Cardíaca/prevención & control , Calidad de Vida , Anciano , Dinamarca , Femenino , Humanos , Masculino , Persona de Mediana Edad
7.
Cardiology ; 142(3): 141-148, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31170719

RESUMEN

Current guidelines do not recommend coronary computed tomography angiography (CCTA) in patients with high levels of coronary calcium, as severe calcification leads to difficulties in estimating stenosis severity due to blooming artifacts obscuring the vessel lumen. Whether the CCTA-derived fractional flow reserve (FFRCT) improves the diagnostic performance of CCTA in patients with high levels of coronary calcification has not been sufficiently evaluated. We hypothesize that a noninvasive diagnostic strategy using FFRCT will perform comparably to an invasive diagnostic strategy in the detection of hemodynamically significant coronary artery disease (CAD) in clinical stable chest pain patients with high levels of coronary calcium. In this prospective, blinded, multicenter study, patients with suspected stable CAD referred for CCTA and demonstrating an Agatston score >399 will be included. Patients accepting inclusion will, in addition to CCTA, undergo invasive coronary angiography (ICA) and invasive FFR measurement. FFRCT analyses are performed by an external core laboratory blinded to any patient data, and the FFRCT results are blinded to all participating study sites. The primary objective is to evaluate whether FFRCT can identify patients with and without hemodynamically significant CAD, when ICA with FFR is the reference standard. A negative study result would question the clinical usefulness of FFRCT in patients with high levels of coronary calcium. A positive study result, however, would imply a reduction in the number of patients referred for coronary catheterization and, at the same time, increase the proportion of patients with hemodynamically significant CAD at the subsequent invasive examination.


Asunto(s)
Angiografía por Tomografía Computarizada , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Reserva del Flujo Fraccional Miocárdico , Calcificación Vascular/diagnóstico por imagen , Calcio/sangre , Cateterismo Cardíaco , Dolor en el Pecho/etiología , Enfermedad de la Arteria Coronaria/fisiopatología , Dinamarca , Hemodinámica , Humanos , Estudios Multicéntricos como Asunto , Valor Predictivo de las Pruebas , Estudios Prospectivos , Ensayos Clínicos Controlados Aleatorios como Asunto , Calcificación Vascular/fisiopatología
8.
Circulation ; 136(19): 1772-1780, 2017 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-28877914

RESUMEN

BACKGROUND: The DANISH study (Danish Study to Assess the Efficacy of ICDs [Implantable Cardioverter Defibrillators] in Patients With Non-Ischemic Systolic Heart Failure on Mortality) did not demonstrate an overall effect on all-cause mortality with ICD implantation. However, the prespecified subgroup analysis suggested a possible age-dependent association between ICD implantation and mortality with survival benefit seen only in the youngest patients. The nature of this relationship between age and outcome of a primary prevention ICD in patients with nonischemic systolic heart failure warrants further investigation. METHODS: All 1116 patients from the DANISH study were included in this prespecified subgroup analysis. We assessed the relationship between ICD implantation and mortality by age, and an optimal age cutoff was estimated nonparametrically with selection impact curves. Modes of death were divided into sudden cardiac death and nonsudden death and compared between patients younger and older than this age cutoff with the use of χ2 analysis. RESULTS: Median age of the study population was 63 years (range, 21-84 years). There was a linearly decreasing relationship between ICD and mortality with age (hazard ratio [HR], 1.03; 95% confidence interval [CI], 1.003-1.06; P=0.03). An optimal age cutoff for ICD implantation was present at ≤70 years. There was an association between reduced all-cause mortality and ICD in patients ≤70 years of age (HR, 0.70; 95% CI, 0.51-0.96; P=0.03) but not in patients >70 years of age (HR, 1.05; 95% CI, 0.68-1.62; P=0.84). For patients ≤70 years old, the sudden cardiac death rate was 1.8 (95% CI, 1.3-2.5) and nonsudden death rate was 2.7 (95% CI, 2.1-3.5) events per 100 patient-years, whereas for patients >70 years old, the sudden cardiac death rate was 1.6 (95% CI, 0.8-3.2) and nonsudden death rate was 5.4 (95% CI, 3.7-7.8) events per 100 patient-years. This difference in modes of death between the 2 age groups was statistically significant (P=0.01). CONCLUSIONS: In patients with systolic heart failure not caused by ischemic heart disease, the association between the ICD and survival decreased linearly with increasing age. In this study population, an age cutoff for ICD implantation at ≤70 years yielded the highest survival for the population as a whole. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00542945.


Asunto(s)
Muerte Súbita Cardíaca/prevención & control , Desfibriladores Implantables , Cardioversión Eléctrica/instrumentación , Insuficiencia Cardíaca Sistólica/terapia , Prevención Primaria/instrumentación , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Distribución de Chi-Cuadrado , Muerte Súbita Cardíaca/etiología , Dinamarca , Cardioversión Eléctrica/efectos adversos , Cardioversión Eléctrica/mortalidad , Femenino , Insuficiencia Cardíaca Sistólica/diagnóstico , Insuficiencia Cardíaca Sistólica/etiología , Insuficiencia Cardíaca Sistólica/mortalidad , Humanos , Estimación de Kaplan-Meier , Modelos Lineales , Masculino , Persona de Mediana Edad , Análisis Multivariante , Modelos de Riesgos Proporcionales , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento , Adulto Joven
9.
Eur Heart J ; 38(6): 413-421, 2017 02 07.
Artículo en Inglés | MEDLINE | ID: mdl-27941018

RESUMEN

Aims: To examine the 3.5 year prognosis of stable coronary artery disease (CAD) as assessed by coronary computed tomography angiography (CCTA) in real-world clinical practice, overall and within subgroups of patients according to age, sex, and comorbidity. Methods and results: This cohort study included 16,949 patients (median age 57 years; 57% women) with new-onset symptoms suggestive of CAD, who underwent CCTA between January 2008 and December 2012. The endpoint was a composite of late coronary revascularization procedure >90 days after CCTA, myocardial infarction, and all-cause death. The Kaplan-Meier estimator was used to compute 91 day to 3.5 year risk according to the CAD severity. Comparisons between patients with and without CAD were based on Cox-regression adjusted for age, sex, comorbidity, cardiovascular risk factors, concomitant cardiac medications, and post-CCTA treatment within 90 days. The composite endpoint occurred in 486 patients. Risk of the composite endpoint was 1.5% for patients without CAD, 6.8% for obstructive CAD, and 15% for three-vessel/left main disease. Compared with patients without CAD, higher relative risk of the composite endpoint was observed for non-obstructive CAD [hazard ratio (HR): 1.28; 95% confidence interval (CI): 1.01-1.63], obstructive one-vessel CAD (HR: 1.83; 95% CI: 1.37-2.44), two-vessel CAD (HR: 2.97; 95% CI: 2.09-4.22), and three-vessel/left main CAD (HR: 4.41; 95% CI :2.90-6.69). The results were consistent in strata of age, sex, and comorbidity. Conclusion: Coronary artery disease determined by CCTA in real-world practice predicts the 3.5 year composite risk of late revascularization, myocardial infarction, and all-cause death across different groups of age, sex, or comorbidity burden.


Asunto(s)
Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Adulto , Anciano , Angina Estable/diagnóstico por imagen , Angina Estable/mortalidad , Estudios de Cohortes , Angiografía por Tomografía Computarizada/mortalidad , Angiografía Coronaria/mortalidad , Enfermedad de la Arteria Coronaria/mortalidad , Dinamarca/epidemiología , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Infarto del Miocardio/mortalidad , Revascularización Miocárdica/mortalidad , Intervención Coronaria Percutánea/mortalidad , Pronóstico
10.
Biochem J ; 468(3): 495-506, 2015 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-25846210

RESUMEN

Class 1 cytokine receptors regulate essential biological processes through complex intracellular signalling networks. However, the structural platform for understanding their functions is currently incomplete as structure-function studies of the intracellular domains (ICDs) are critically lacking. The present study provides the first comprehensive structural characterization of any cytokine receptor ICD and demonstrates that the human prolactin (PRL) receptor (PRLR) and growth hormone receptor (GHR) ICDs are intrinsically disordered throughout their entire lengths. We show that they interact specifically with hallmark lipids of the inner plasma membrane leaflet through conserved motifs resembling immuno receptor tyrosine-based activation motifs (ITAMs). However, contrary to the observations made for ITAMs, lipid association of the PRLR and GHR ICDs was shown to be unaccompanied by changes in transient secondary structure and independent of tyrosine phosphorylation. The results of the present study provide a new structural platform for studying class 1 cytokine receptors and may implicate the membrane as an active component regulating intracellular signalling.


Asunto(s)
Membrana Celular/metabolismo , Modelos Moleculares , Receptores de Prolactina/metabolismo , Receptores de Somatotropina/metabolismo , Línea Celular , Membrana Celular/química , Dicroismo Circular , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Membrana Dobles de Lípidos/química , Membrana Dobles de Lípidos/metabolismo , Resonancia Magnética Nuclear Biomolecular , Fragmentos de Péptidos/química , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/metabolismo , Fosfatidilcolinas/química , Fosfatidilcolinas/metabolismo , Fosfatidilserinas/química , Fosfatidilserinas/metabolismo , Pliegue de Proteína , Estructura Terciaria de Proteína , Receptores de Prolactina/química , Receptores de Prolactina/genética , Receptores de Somatotropina/química , Receptores de Somatotropina/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Dispersión del Ángulo Pequeño , Transducción de Señal , Tirosina/metabolismo , Difracción de Rayos X
11.
Mol Pharm ; 12(11): 4067-76, 2015 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-26393273

RESUMEN

The aim of this study was to investigate if molecular interactions between the weak base cinnarizine and lipolysis products were affecting the morphology of precipitated drug formed during in vitro lipolysis. In vitro lipolysis studies of a self-nanoemulsifying drug delivery system with or without cinnarizine were conducted. The digestion phases (aqueous phase and pellet phase) were separated by ultracentrifugation, and the pellet was isolated and lyophilized. The lyophilized pellets were examined by X-ray powder diffraction, (13)C solid-state nuclear magnetic resonance ((13)C NMR), (1)H liquid-state NMR ((1)H NMR) spectroscopy and differential scanning calorimetry (DSC). The (13)C NMR data indicated that the carbonyl groups and aliphatic part of the lipids undergo structural changes when the pellet contains cinnarizine. The (1)H NMR data suggests interactions occurring around the nitrogens on cinnarizine and the carboxylic group of fatty acids. DSC thermograms showed cinnarizine to be homogeneously incorporated into the lipids of the pellet, and no free amorphous cinnarizine was present. The three techniques (13)C NMR, (1)H NMR, and DSC complement each other and suggest interactions to occur between fatty acids and cinnarizine, which in turn favors amorphous precipitation.


Asunto(s)
Bloqueadores de los Canales de Calcio/química , Precipitación Química , Cinarizina/química , Sistemas de Liberación de Medicamentos , Lípidos/química , Rastreo Diferencial de Calorimetría , Química Farmacéutica , Portadores de Fármacos , Lipólisis , Solubilidad , Factores de Tiempo
12.
Angew Chem Int Ed Engl ; 54(52): 15756-61, 2015 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-26563985

RESUMEN

Metal-ion-responsive transcriptional regulators within the MerR family effectively discriminate between mono- and divalent metal ions. Herein we address the origin of the specificity of the CueR protein for monovalent metal ions. Several spectroscopic techniques were employed to study Ag(I) , Zn(II) , and Hg(II) binding to model systems encompassing the metal-ion-binding loop of CueR from E. coli and V. cholerae. In the presence of Ag(I) , a conserved cysteine residue displays a pKa  value for deprotonation of the thiol that is close to the physiological pH value. This property is only observed with the monovalent metal ion. Quantum chemically optimized structures of the CueR metal site with Cys 112 protonated demonstrate that the conserved Ser 77 backbone carbonyl oxygen atom from the other monomer of the homodimer is "pulled" towards the metal site. A common allosteric mechanism of the metalloregulatory members of the MerR family is proposed. For CueR, the mechanism relies on the protonation of Cys 112.

13.
Chemphyschem ; 15(18): 3929-32, 2014 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-25303164

RESUMEN

ß-nuclear magnetic resonance (NMR) spectroscopy is highly sensitive compared to conventional NMR spectroscopy, and may be applied for several elements across the periodic table. ß-NMR has previously been successfully applied in the fields of nuclear and solid-state physics. In this work, ß-NMR is applied, for the first time, to record an NMR spectrum for a species in solution. (31)Mg ß-NMR spectra are measured for as few as 10(7) magnesium ions in ionic liquid (EMIM-Ac) within minutes, as a prototypical test case. Resonances are observed at 3882.9 and 3887.2 kHz in an external field of 0.3 T. The key achievement of the current work is to demonstrate that ß-NMR is applicable for the analysis of species in solution, and thus represents a novel spectroscopic technique for use in general chemistry and potentially in biochemistry.


Asunto(s)
Magnesio/análisis , Espectroscopía de Resonancia Magnética/métodos , Líquidos Iónicos/química , Radioisótopos/análisis , Soluciones
14.
Pharm Res ; 30(1): 280-9, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22996567

RESUMEN

PURPOSE: To understand the transformation pathways amongst anhydrate/hydrate solid forms of sodium naproxen and to highlight the importance of a polymorphic dihydrate within this context. METHODS: Multi-temperature dynamic vapour sorption (DVS) analysis combined with variable-humidity X-ray powder diffraction (XRPD) to establish the transformation pathways as a function of temperature and humidity. XRPD and thermogravimetric analysis (TGA) to characterise bulk samples. Monitoring of in-situ dehydration using solid-state (13)C CP/MAS spectroscopy. RESULTS: At 25 °C, anhydrous sodium naproxen (AH) transforms directly to one dihydrate polymorph (DH-II). At 50 °C, AH transforms stepwise to a monohydrate (MH) then to the other dihydrate polymorph (DH-I). DH-II transforms to a tetrahydrate (TH) more readily than DH-I transforms to TH. Both dihydrate polymorphs transform to the same MH. CONCLUSIONS: The properties of the polymorphic dihydrate control the transformation pathways of sodium naproxen.


Asunto(s)
Antiinflamatorios no Esteroideos/química , Naproxeno/química , Agua/química , Cristalización , Humedad , Difracción de Polvo , Sodio/química , Temperatura , Termogravimetría , Difracción de Rayos X
15.
Analyst ; 138(7): 2096-103, 2013 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-23400050

RESUMEN

A method for quantification of total soluble protein-derived thiols in beer was developed based on the formation of fluorescent adducts with the maleimide compound ThioGlo 1. The problem of interference from fluorescent adducts of sulfite and ThioGlo 1 was solved by HPLC separation of the adducts followed by fluorescence detection. Using standard addition of GSH, a detection limit of 0.028 µM thiols was achieved. The application and validation of the method was demonstrated for beers with different color intensities, and the application range is in principle for any biological system containing thiols. However, the quantification of cysteine was complicated by a lower fluorescence response of its ThioGlo 1 adducts. Based on the studies of the responses of a series of cysteine-derived thiols and (1)H NMR studies of the structures of ThioGlo 1 adducts with GSH and cysteine, it was concluded that thiols with a neighboring free amino group yield ThioGlo 1 adducts with a reduced fluorescence intensity.


Asunto(s)
Cerveza/análisis , Proteínas/química , Compuestos de Sulfhidrilo/análisis , Cromatografía Líquida de Alta Presión/métodos , Cisteína/química , Colorantes Fluorescentes/química , Glutatión/química , Naftalenos , Resonancia Magnética Nuclear Biomolecular , Pirroles
16.
Carbohydr Polym ; 308: 120649, 2023 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-36813341

RESUMEN

Heparin, a major anticoagulant drug, comprises a complex mixture of motifs. Heparin is isolated from natural sources while being subjected to a variety of conditions but the detailed effects of these on heparin structure have not been studied in depth. Therefore, the result of exposing heparin to a range of buffered environments, ranging pH values from 7 to 12, and temperatures of 40, 60 and 80 °C were examined. There was no evidence of significant N-desulfation or 6-O-desulfation in glucosamine residues, nor of chain scission, however, stereochemical re-arrangement of α-L-iduronate 2-O-sulfate to α-L-galacturonate residues occurred in 0.1 M phosphate buffer at pH 12/80 °C. The results confirm the relative stability of heparin in environments like those during extraction and purification processes; on the other hand, the sensitivity of heparin to pH 12 in buffered solution at high temperature is highlighted, providing an important insight for heparin manufacturers.


Asunto(s)
Heparina , Sulfatos , Heparina/química , Ácido Idurónico , Fosfatos
17.
Clin Gastroenterol Hepatol ; 10(4): 434-8.e1, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22155560

RESUMEN

BACKGROUND & AIMS: Patients with painful chronic pancreatitis (CP) might have abnormal brain function. We assessed cortical thickness in brain areas involved in visceral pain processing. METHODS: We analyzed brain morphologies of 19 patients with painful CP and compared them with 15 healthy individuals (controls) by using a 3T magnetic resonance scanner. By using an automated method with surface-based cortical segmentation, we assessed cortical thickness of the primary (SI) and secondary (SII) somatosensory cortex; prefrontal cortex (PFC); frontal cortex (FC); anterior (ACC), mid (MCC), and posterior (PCC) cingulate cortex; and insula. The occipital middle sulcus was used as a control area. The pain score was determined on the basis of the average daily amount of pain during 1 week. RESULTS: Compared with controls, patients with CP had reduced overall cortical thickness (P = .0012), without effects of modification for diabetes, alcoholic etiologies, or opioid treatment (all P values >.05). In patients with CP, the cortical thickness was decreased in SII (P = .002, compared with controls), PFC (P = .046), FC (P = .0003), MCC (P = .001), and insula (P = .002). There were no differences in cortical thickness between CP patients and controls in the control area (P = .20), SI (P = .06), ACC (P = .95), or PCC (P = .42). Cortical thickness in the affected areas correlated with pain score (r = 0.47, P = .003). CONCLUSIONS: In patients with CP, brain areas involved in pain processing have reduced cortical thickness. As a result of long-term, ongoing pain input to the neuromatrix, cortical thickness might serve as a measure for overall pain system dysfunction, as observed in other diseases characterized by chronic pain.


Asunto(s)
Corteza Cerebral/patología , Dimensión del Dolor/métodos , Pancreatitis Crónica/complicaciones , Dolor Visceral/fisiopatología , Adulto , Anciano , Corteza Cerebral/diagnóstico por imagen , Femenino , Experimentación Humana , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Radiografía
18.
JACC Cardiovasc Imaging ; 15(6): 1046-1058, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35680213

RESUMEN

BACKGROUND: The influence of extensive coronary calcifications on the diagnostic and prognostic value of coronary computed tomography angiography-derived fractional flow reserve (FFRCT) has been scantily investigated. OBJECTIVES: The purpose of this study was to investigate the diagnostic and short-term role of FFRCT in chest pain patients with Agatston score (AS) >399. METHODS: This was a prospective multicenter study of 260 stable patients with suspected coronary artery disease (CAD) and AS >399. FFRCT was measured blinded by an independent core laboratory. All patients underwent invasive coronary angiography (ICA) and FFR if indicated. The agreement of FFRCT ≤0.80 with hemodynamically significant CAD on ICA/FFR (≥50% left main or ≥70% epicardial artery stenosis and/or FFR ≤0.80) was assessed. Patients undergoing FFR had colocation FFRCT measured, and the lowest per-patient FFRCT was registered in all patients. The association among per-patient FFRCT, coronary revascularization, and major clinical events (all-cause mortality, myocardial infarction, or unstable angina hospitalization) at 90-day follow-up was evaluated. RESULTS: Median age and AS were 68.5 years (IQR: 63-74 years) and 895 (IQR: 587-1,513), respectively. FFRCT was ≤0.80 in 204 patients (78%). Colocation FFRCT (n = 112) showed diagnostic accuracy, sensitivity, and specificity to identify hemodynamically significant CAD of 71%, 87%, and 54%. The area under the receiver-operating characteristics curve (AUC) was 0.75. When using the lowest FFRCT (n = 260), per-patient accuracy, sensitivity, and specificity were 57%, 95%, and 32%, respectively. The AUC was 0.84. A total of 85 patients underwent revascularization, and FFRCT was ≤0.80 in 96% of these. During follow-up, major clinical events occurred in 3 patients (1.2%), all with FFRCT ≤0.80. CONCLUSIONS: Most patients with AS >399 had FFRCT ≤0.80. Using ICA/FFR as the reference revealed a moderate diagnostic accuracy of colocation FFRCT. Compared with the lowest per-patient FFRCT, colocation FFRCT measurement improved diagnostic accuracy and specificity. The 90-day follow-up was favorable with few coronary revascularizations and no major clinical events occurring in patients with FFRCT >0.80. (Use of FFR-CT in Stable Intermediate Chest Pain Patients With Severe Coronary Calcium Score [FACC]; NCT03548753).


Asunto(s)
Calcinosis , Enfermedad de la Arteria Coronaria , Estenosis Coronaria , Reserva del Flujo Fraccional Miocárdico , Dolor en el Pecho , Angiografía por Tomografía Computarizada , Angiografía Coronaria/métodos , Enfermedad de la Arteria Coronaria/complicaciones , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/terapia , Estenosis Coronaria/complicaciones , Estenosis Coronaria/diagnóstico por imagen , Estenosis Coronaria/terapia , Vasos Coronarios/diagnóstico por imagen , Humanos , Valor Predictivo de las Pruebas , Estudios Prospectivos , Tomografía Computarizada por Rayos X
19.
Biomacromolecules ; 12(5): 1844-50, 2011 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-21462966

RESUMEN

Hydration of rhamnogalacturonan-I (RG-I) derived from potato cell wall was analyzed by (13)C single-pulse (SP) magic-angle-spinning (MAS) and (13)C cross-polarization (CP) MAS nuclear magnetic resonance (NMR) and supported by (2)H SP/MAS NMR experiments. The study shows that the arabinan side chains hydrate more readily than the galactan side chains and suggests that the overall hydration properties can be controlled by modifying the ratio of these side chains. Enzymatic modification of native (NA) RG-I provided samples with reduced content of arabinan (sample DA), galactan (sample DG), or both side chains (sample DB). Results of these samples suggested that hydration properties were determined by the length and character of the side chains. NA and DA exhibited similar hydration characteristics, whereas DG and DB were difficult to hydrate because of the less hydrophilic properties of the rhamnose-galacturonic acid (Rha-GalA) backbone in RG-I. Potential food ingredient uses of RG-I by tailoring of its structure are discussed.


Asunto(s)
Pared Celular/química , Espectroscopía de Resonancia Magnética/métodos , Pectinas/química , Solanum tuberosum/química , Agua/química , Isótopos de Carbono
20.
Acta Odontol Scand ; 69(3): 151-7, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21198339

RESUMEN

OBJECTIVE: Drooling in neurodegenerative diseases is associated with social impediment. Previous treatments of drooling have little effect or are effective but with severe side effects. Therefore, there is a need to test new methods such as the use of botulinum toxin type A (BTX-A). MATERIAL AND METHODS: This open, prospective study deals with treatment of drooling in 12 patients with amyotrophic lateral sclerosis and three with Parkinson's disease. Injections of BTX-A (Botox) were given into the parotid (25-40 units) and submandibular (15-30 units) glands with ultrasonographic guidance. After BTX-A treatment, the patients were followed for 2 months with evaluations every second week by means of self-assessed rating scales for drooling intensity, discomfort and treatment effect, and determination of unstimulated whole saliva (UWS) flow rate, and inorganic and organic UWS composition. The treatment was repeated up to four times, but seven patients dropped out shortly after the first treatment due to marked worsening of their disease-related condition. RESULTS: Drooling and flow were reduced (P < 0.05) 2 weeks after treatment, without side-effects. The maximal reductions during the observation period were 40% for drooling and 30% for flow. There was a systematic variation in flow during the observation period, with an initial decrease and then an increase followed by a second decrease. Amylase activity and total protein concentration generally increased with decreasing flow (P ≤ 0.03). CONCLUSION: Inhibition of acetylcholine release from postganglionic parasympathetic nerve endings by injection of BTX-A into salivary glands seemed useful for secondary sialorrhoea, although cyclic variations in flow may occur, possibly due to transitory sprouting and regeneration.


Asunto(s)
Esclerosis Amiotrófica Lateral/complicaciones , Toxinas Botulínicas Tipo A/uso terapéutico , Fármacos Neuromusculares/uso terapéutico , Enfermedad de Parkinson/complicaciones , Sialorrea/tratamiento farmacológico , Acetilcolina/metabolismo , Anciano , Algoritmos , Toxinas Botulínicas Tipo A/administración & dosificación , Toxinas Botulínicas Tipo A/farmacología , Femenino , Humanos , Inyecciones , Masculino , Fármacos Neuromusculares/administración & dosificación , Fármacos Neuromusculares/farmacología , Glándula Parótida/efectos de los fármacos , Estudios Prospectivos , Saliva/química , Saliva/metabolismo , Salivación/efectos de los fármacos , Tasa de Secreción/efectos de los fármacos , Sialorrea/etiología , Glándula Submandibular/efectos de los fármacos , Ultrasonografía Intervencional
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA