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2.
Nat Commun ; 13(1): 2998, 2022 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-35637202

RESUMEN

Understanding how fast short-range interactions build up long-range order is one of the most intriguing topics in condensed matter physics. FeRh is a test specimen for studying this problem in magnetism, where the microscopic spin-spin exchange interaction is ultimately responsible for either ferro- or antiferromagnetic macroscopic order. Femtosecond laser excitation can induce ferromagnetism in antiferromagnetic FeRh, but the mechanism and dynamics of this transition are topics of intense debates. Employing double-pump THz emission spectroscopy has enabled us to dramatically increase the temporal detection window of THz emission probes of transient states without sacrificing any loss of resolution or sensitivity. It allows us to study the kinetics of emergent ferromagnetism from the femtosecond up to the nanosecond timescales in FeRh/Pt bilayers. Our results strongly suggest a latency period between the initial pump-excitation and the emission of THz radiation by ferromagnetic nuclei.

3.
Acta Crystallogr E Crystallogr Commun ; 78(Pt 2): 98-102, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-35145731

RESUMEN

A tetra-nuclear complex with an open-cubane-like core structure was synthesized from 2-meth-oxy-6-(pyridin-2-yl-hydrazonometh-yl)phenol (HL), namely, cyclo-tetra-kis-(µ-2-meth-oxy-6-{[2-(pyridin-2-yl)hydrazin-1-yl-idene]meth-yl}pheno-lato)tetra-nickel(II) tetra-kis-(perchlorate) aceto-nitrile monosolvate dihydrate, [Ni4(C13H12N3O2)4](ClO4)4·C2H3N·2H2O, and characterized using micro-analytical and spectroscopic techniques. The crystal-structure determination reveals the formation of a distorted Ni4O4 cubane-like core architecture encapsulated by four hydrazone Schiff base (HL) mol-ecules. A open-cube tetra-nuclear architecture is created in which nickel(II) ions of the NiN2O3 unit are connected by µ2-O anions of the phenolate moiety of HL. In this complex, each Ni centre has a slightly distorted square-pyramidal coordination environment. The supra-molecular architectures are stabilized via the presence of various inter-molecular hydrogen bonds and (ar-yl-aryl, ar-yl-chelate and chelate-chelate) stacking inter-actions.

4.
Breast Cancer Res Treat ; 190(2): 287-293, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34515905

RESUMEN

PURPOSE: Older cancer survivors required medical care during the COVID-19 pandemic, but there are limited data on medical care in this age group. METHODS: We evaluated care disruptions in a longitudinal cohort of non-metastatic breast cancer survivors aged 60-98 from five US regions (n = 321). Survivors completed a web-based or telephone survey from May 27, 2020 to September 11, 2020. Care disruptions included interruptions in seeing or speaking to doctors, receiving medical treatment or supportive therapies, or filling prescriptions since the pandemic began. Logistic regression models evaluated associations between care disruptions and education, medical, psychosocial, and COVID-19-related factors. Multivariate models included age, county COVID-19 death rates, comorbidity, and post-diagnosis time. RESULTS: There was a high response rate (n = 262, 81.6%). Survivors were 32.2 months post-diagnosis (SD 17.5, range 4-73). Nearly half (48%) reported a medical disruption. The unadjusted odds of care disruptions were higher with each year of education (OR 1.22, 95% CI 1.08-1.37, p = < 0.001) and increased depression by CES-D score (OR 1.04, CI 1.003-1.08, p = 0.033) while increased tangible support decreased the odds of disruptions (OR 0.99, 95% CI 0.97-0.99, p = 0.012). There was a trend between disruptions and comorbidities (unadjusted OR 1.13 per comorbidity, 95% CI 0.99-1.29, p = 0.07). Adjusting for covariates, higher education years (OR1.23, 95% CI 1.09-1.39, p = 0.001) and tangible social support (OR 0.98 95% CI 0.97-1.00, p = 0.006) remained significantly associated with having care disruptions. CONCLUSION: Older breast cancer survivors reported high rates of medical care disruptions during the COVID-19 pandemic and psychosocial factors were associated with care disruptions. CLINICALTRIALS. GOV IDENTIFIER: NCT03451383.


Asunto(s)
Neoplasias de la Mama , COVID-19 , Supervivientes de Cáncer , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/terapia , Femenino , Humanos , Persona de Mediana Edad , Pandemias , SARS-CoV-2
5.
Nat Commun ; 12(1): 2865, 2021 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-34001880

RESUMEN

The spin-phonon interaction in spin density wave (SDW) systems often determines the free energy landscape that drives the evolution of the system. When a passing energy flux, such as photoexcitation, drives a crystalline system far from equilibrium, the resulting lattice displacement generates transient vibrational states. Manipulating intermediate vibrational states in the vicinity of the critical point, where the SDW order parameter changes dramatically, would then allow dynamical control over functional properties. Here we combine double photoexcitation with an X-ray free-electron laser (XFEL) probe to control and detect the lifetime and magnitude of the intermediate vibrational state near the critical point of the SDW in chromium. We apply Landau theory to identify the mechanism of control as a repeated partial quench and sub picosecond recovery of the SDW. Our results showcase the capabilities to influence and monitor quantum states by combining multiple optical photoexcitations with an XFEL probe. They open new avenues for manipulating and researching the behaviour of photoexcited states in charge and spin order systems near the critical point.

6.
Res Sq ; 2021 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-33880464

RESUMEN

PurposeOlder cancer survivors required medical care during the COVID-19 pandemic despite infection risks, but there are limited data on medical care in this age group. METHODS: We evaluated care disruptions in a longitudinal cohort of non-metastatic breast cancer survivors ages 60-98 from five US regions (n=321). Survivors completed a web-based or telephone survey from May 27, 2020 to September 11, 2020. Care disruptions included self-reported interruptions in ability to see doctors, receive treatment or supportive therapies, or fill prescriptions. Logistic regression models evaluated bivariate and multivariate associations between care disruptions and education, medical, psychosocial and COVID-19-related factors. Multivariate models included age, county COVID-19 rates, comorbidity and post-diagnosis time. RESULTS: There was a high response rate (n=262, 81.6%). Survivors were 32.2 months post-diagnosis (SD 17.5, range 4-73). Nearly half (48%) reported a medical disruption. The unadjusted odds of care disruptions were significantly higher with more education (OR 1.23 per one-year increase, 95% CI 1.09-1.39, p =0.001) and greater depression (OR 1.04 per one-point increase in CES-D score, CI 1.003-1.08, p=0.033); tangible support decreased the odds of disruptions (OR 0.99, 95% CI 0.97-0.99 per one-point increase, p=0.012). There was a trend for associations between disruptions and comorbidity (unadjusted OR 1.13 per 1 added comorbidity, 95% CI 0.99-1.29, p=0.07). Adjusting for covariates, only higher education (p=0.001) and tangible social support (p=0.006) remained significantly associated with having care disruptions. CONCLUSIONS: Older breast cancer survivors reported high rates of medical care disruptions during the COVID-19 pandemic and psychosocial factors were associated with care disruptions.

7.
J Hum Hypertens ; 32(3): 171-179, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29330420

RESUMEN

Cognitive impairment is common in patients with hypertension. Left ventricular hypertrophy (LVH) is recognised as a marker of hypertension-related organ damage and is a strong predictor of coronary artery disease, heart failure and stroke. There is evidence that LVH is independently associated with cognitive impairment, even after adjustment for the presence of hypertension. We conducted a systematic review that examined cognitive impairment in adults with LVH. Independent searches were performed in Ovid MEDLINE, Ovid psycInfo and PubMed with the terms left ventricular hypertrophy and cognition. Seventy-three studies were identified when both searches were combined. After limiting the search to studies that were: (1) reported in English; (2) conducted in humans; (3) in adults aged 50 years and older; and (4) investigated the relationship between LVH and cognitive performance, nine papers were included in this systematic review. The majority of studies found an association between LVH and cognitive performance. Inspection of results indicated that individuals with LVH exhibited a lower performance in cognitive tests, when compared to individuals without LVH. Memory and executive functions were the cognitive domains that showed a specific vulnerability to the presence of LVH. A possible mechanism for the relationship between LVH and cognition is the presence of cerebral white matter damage. White matter lesions occur frequently in patients with LVH and may contribute to cognitive dysfunction. Together, the results of this review suggest that memory impairment and executive dysfunction are the cognitive domains that showed a particular association with the presence of LVH.


Asunto(s)
Disfunción Cognitiva/etiología , Hipertrofia Ventricular Izquierda/complicaciones , Cognición/fisiología , Humanos
8.
Phys Rev Lett ; 117(5): 056401, 2016 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-27517781

RESUMEN

Symmetry breaking and the emergence of order is one of the most fascinating phenomena in condensed matter physics. It leads to a plethora of intriguing ground states found in antiferromagnets, Mott insulators, superconductors, and density-wave systems. Exploiting states of matter far from equilibrium can provide even more striking routes to symmetry-lowered, ordered states. Here, we demonstrate for the case of elemental chromium that moderate ultrafast photoexcitation can transiently enhance the charge-density-wave (CDW) amplitude by up to 30% above its equilibrium value, while strong excitations lead to an oscillating, large-amplitude CDW state that persists above the equilibrium transition temperature. Both effects result from dynamic electron-phonon interactions, providing an efficient mechanism to selectively transform a broad excitation of the electronic order into a well-defined, long-lived coherent lattice vibration. This mechanism may be exploited to transiently enhance order parameters in other systems with coupled degrees of freedom.

10.
Indian J Pharm Sci ; 77(1): 55-61, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25767319

RESUMEN

Fluconazole is a broad spectrum antifungal agent that has been extensively applied for the management of oral, pharyngeal and cutaneous candidiasis. Fluconazole has a high volume of distribution (0.55-0.65 l/kg) and has systemic toxicity due to high drug-drug interaction. The present study focuses on the formulation of bioadhesive film as a controlled release carrier for fluconazole. The formulation was intended to provide localized delivery of fluconazole exclusively at the site of infection, thereby reducing its total dose and hence, dose-related toxicities. Bioadhesive films were prepared by solvent casting method using sodium alginate and polyvinyl alcohol alone as well as in various combinations. Prepared films were evaluated for physical characteristics like, weight and content uniformity, film thickness, swelling index, microenvironment pH and folding endurance. In vitro drug release, in vitro and ex vivo residence time, bioadhesive strength and skin irritation were also studied. Accelerated stability study was conducted on the optimized formulation as per ICH guidelines. Weight of all the films were not more than 20 mg. Thickness of the films ranged between 0.09 to 0.15 mm whereas swelling indices showed a high extent of variation. Films composed of polyvinyl alcohol alone provided a swelling index of 6%. Bioadhesive strength was found to be more than 18 g. Microenvironment pH was near to 7.0 for most of the formulations. Ex vivo residence time of optimized batch was more than 5 h and it provided controlled drug release up to 8 h. As revealed in FT-IR and DSC studies, drug was found to be compatible with the excipients used in this study.

11.
Br J Pharmacol ; 169(1): 51-68, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23425116

RESUMEN

BACKGROUND AND PURPOSE: AMG 181 is a human anti-α4 ß7 antibody currently in phase 1 and 2 trials in subjects with inflammatory bowel diseases. AMG 181 specifically targets the α4 ß7 integrin heterodimer, blocking its interaction with mucosal addressin cell adhesion molecule-1 (MAdCAM-1), the principal ligand that mediates α4 ß7 T cell gut-homing. EXPERIMENTAL APPROACH: We studied the in vitro pharmacology of AMG 181, and the pharmacokinetics and pharmacodynamics of AMG 181 after single or weekly i.v. or s.c. administration in cynomolgus monkeys for up to 13 weeks. KEY RESULTS: AMG 181 bound to α4 ß7 , but not α4 ß1 or αE ß7 , and potently inhibited α4 ß7 binding to MAdCAM-1 (but not vascular cell adhesion molecule-1) and thus inhibited T cell adhesion. Following single i.v. administration, AMG 181 Cmax was dose proportional from 0.01 to 80 mg·kg(-1) , while AUC increased more than dose proportionally. Following s.c. administration, dose-proportional exposure was observed with single dose ranging from 5 to 80 mg·kg(-1) and after 13 weekly doses at levels between 20 and 80 mg·kg(-1) . AMG 181 accumulated two- to threefold after 13 weekly 80 mg·kg(-1) i.v. or s.c. doses. AMG 181 had an s.c. bioavailability of 80%. The linear elimination half-life was 12 days, with a volume of distribution close to the intravascular plasma space. The mean trend for the magnitude and duration of AMG 181 exposure, immunogenicity, α4 ß7 receptor occupancy and elevation in gut-homing CD4+ central memory T cell count displayed apparent correlations. CONCLUSIONS AND IMPLICATIONS: AMG 181 has in vitro pharmacology, and pharmacokinetic/pharmacodynamic and safety characteristics in cynomolgus monkeys that are suitable for further investigation in humans.


Asunto(s)
Anticuerpos Monoclonales/administración & dosificación , Linfocitos T CD4-Positivos/metabolismo , Inmunoglobulinas/metabolismo , Integrinas/metabolismo , Mucoproteínas/metabolismo , Animales , Anticuerpos Monoclonales/farmacocinética , Anticuerpos Monoclonales/farmacología , Anticuerpos Monoclonales Humanizados , Disponibilidad Biológica , Linfocitos T CD4-Positivos/inmunología , Adhesión Celular/efectos de los fármacos , Moléculas de Adhesión Celular , Línea Celular , Relación Dosis-Respuesta a Droga , Femenino , Semivida , Humanos , Inyecciones Intravenosas , Inyecciones Subcutáneas , Macaca fascicularis , Masculino , Distribución Tisular
12.
Int J Cardiol ; 167(4): 1226-31, 2013 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-22483251

RESUMEN

BACKGROUND: The natural history of aortic stenosis (AS) in elderly patients remains poorly defined. In an elderly cohort over long-term follow-up, we assessed: 1) rates and predictors of hemodynamic progression and 2) composite aortic valve replacement (AVR) or death endpoint. METHODS: Consecutive Department of Veterans' Affairs patients with AS (>60 years) were prospectively enrolled between 1988 and 1994 (n=239) and followed until 2008. Patients with ≥ 2 trans-thoracic echocardiograms >6 months apart were included in the progression analysis (n=147). Baseline demographics, comorbidities and echocardiography parameters were recorded. Follow-up was censored at AVR/death. RESULTS: The age of patients was 73 ± 6 years; 82% were male. Baseline AS severity was mild (67%), moderate (23%) and severe (10%). Follow-up was 6.5 ± 4 years (range: 1-17 years). Annualized mean aortic valve gradient progression rates were: mild AS 4 ± 4 mmHg/year; moderate AS 6 ± 5 mmHg/year and severe AS 10 ± 8 mmHg/year (p<0.001). Five-year event-free survival was 66 ± 5%, 23 ± 7% and 20 ± 10% for mild, moderate and severe AS respectively. Progression to severe AS occurred in 35% and 74% of patients with mild and moderate AS respectively. Independent predictors of rapid progression were: baseline AS severity (per grade) (OR 2.6, p=0.001), aortic valve calcification (per grade) (OR 2.1, p=0.01), severe renal impairment (OR 4.0, p=0.04) and anemia (OR 2.3, p=0.05). CONCLUSIONS: In elderly patients, hemodynamic progression of AS is predicted by AS severity, renal function, aortic valve calcification and history of anemia. These factors identify patients at high risk of rapid hemodynamic progression, for whom more frequent clinical and echocardiographic surveillance is advisable.


Asunto(s)
Estenosis de la Válvula Aórtica/diagnóstico , Estenosis de la Válvula Aórtica/mortalidad , Progresión de la Enfermedad , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Tasa de Supervivencia/tendencias
14.
Transplant Proc ; 44(7): 2197-201, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22974954

RESUMEN

INTRODUCTION: Machine perfusion to preserve kidneys for transplantation has grown over the past decade with demonstrated diagnostic and therapeutic benefits. Flow and resistance patterns are used to predict delayed graft function (DGF) and posttransplant graft survival. Preimplantation biopsies obtained serve a similar role in evaluating kidneys especially if they meet expanded criteria. The reliability of available data is greater if there is a correlation among various forms of assessment. In this study we attempted to study serial pump parameters that might correlate with abnormal findings in preimplantation biopsies and subsequently in outcomes after transplantation. METHODS: Two hundred sixty-eight kidneys were assessed for changes in pump pressures in mm Hg, flow in mL/min, resistance in mm Hg/mL/min, and temperature in °C at 15-minute intervals. Allografts were separated into two groups on the basis of pathology; group 1 showed abnormal (AH) and group 2 normal histology (NH). AH was defined by the presence of glomerulosclerosis in ≥10% of sampled glomeruli or arteriosclerosis affecting at least 10% of the arterial lumens of sampled intrarenal arteries. We assessed discordance between frozen and permanent sections. Measured clinical outcomes included DGF, 1-year graft survival, 1-year serum creatinine and estimated glomerular filtration rate (eGFR). Statistical analysis was performed using a paired Student t test and chi-square analysis. RESULTS: Compared to NH kidneys, those with AH showed uniformly significant lower flow rates and higher resistances during the entire perfusion. Graft pathology did not predict DGF (70% versus 60%, P = .45). However, 1-year graft survival (96.2% versus 80%, P = .07) and eGFR (58 versus 48 mL/min, P = .19) were lower among kidneys with AH, though these matrics did not reach significance. CONCLUSION: Preimplantation biopsy findings correlated with flow and resistance to perfusion. If a discrepancy is evident upon evaluation of a donor kidney, a repeat biopsy is prudent prior to discarding or using the organ.


Asunto(s)
Arteriosclerosis/fisiopatología , Glomeruloesclerosis Focal y Segmentaria/fisiopatología , Trasplante de Riñón , Humanos , Perfusión
15.
Transplant Proc ; 44(7): 2202-6, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22974955

RESUMEN

INTRODUCTION: Pulsatile pump perfusion of potential kidneys for transplantation is known to decrease the rate of delayed graft function (DGF) and improve their 1-year survival. Flow and resistance parameters are often used to determine the suitability of kidneys for transplantation. Kidneys with low flow rates are often subjected to higher pressures to improve flow. This study evaluated the effect of higher pump pressures on posttransplant renal function. METHODS: We performed a retrospective analysis of 73 deceased donor kidneys preserved using pump perfusion (LifePort) at our center between May 2006 and September 2009. We calculated the mean pump pressure (MP) for the duration of perfusion of each kidney, using systolic pressure (SP) and diastolic pressure (DP) readings with the following formula: (MP = DP + 1/3 (SP - DP). The kidneys were divided into a low (LP; n = 49) and a high-pressure group (HP; n = 24) based on a MP cutoff value of 23 mm Hg. The two groups were then compared for differences in perfusion dynamics and primary endpoints including DGF and 1-year graft survival. Statistical analysis was performed using paired Student t test and chi-square analysis. RESULTS: The two groups were comparable for donor age, extended criteria, sensitization, and cold ischemic times. They differed significantly in higher initial (0.65 ± 0.4 versus 0.4 ± 0.2, P = .01), average (0.25 ± 0.08 versus 0.18 ± 0.06, P = .0006), and terminal resistance (0.21 ± 0.07 versus 0.17 ± 0.06, P = .008) of HP versus LP kidneys. Flow rates were comparable between the two groups. DGF was higher in HP kidneys (75% versus 40%, P = .006) with similar 1-year graft survival (87.5% versus 89%, P = .7). CONCLUSIONS: Perfusate flow through a kidney can be improved by increasing pressure settings to overcome elevated resistance. This maneuver was not associated with a lower rate of DGF after transplantation. One-year graft survival remained unaffected.


Asunto(s)
Trasplante de Riñón , Donantes de Tejidos , Perfusión , Presión , Estudios Retrospectivos
16.
Transplant Proc ; 44(7): 2207-12, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22974956

RESUMEN

UNLABELLED: Pulsatile pump perfusion of kidney transplants is known to decrease delayed graft function (DGF) and improve 1 year graft survival when compared to static cold preservation. Kidneys with better flow and resistance parameters on perfusion are likely to have a better post transplant function. These parameters are commonly used to evaluate kidneys being considered for transplantation. This study assesses the time frame for a kidney within which it reaches optimal perfusion parameters. All kidneys pumped between 5/2006 and 9/2009 on a Lifeport© kidney transporter at our local organ procurement agency were studied. 190 kidneys were evaluated and then divided into two groups based on whether terminal flows increased or declined after prolonged perfusion. All kidneys were assessed for changes in flow (F), resistance (R) and temperature at 15 minute intervals. Discards, DGF and one year graft survival were noted. The Student paired t test and Chi-square analysis were used to compare data. A multiple logistic regression analysis was performed to study independent predictors of DGF on pump perfusion. RESULTS: For all kidneys, the mean initial flow was 59 ± 35 mL/min which improved to an average flow of 128 ± 38 mL/min with continued perfusion. The maximal flow and terminal flows were 148 ± 51 and 135 ± 38 mL/min respectively. The flows at 2, 4, and 6 hours was 125 ± 41, 128 ± 42 and 130 ± 39 mL/min respectively. Kidneys that improved on continued perfusion had a significantly lower discard rate (20 vs 34% p < 0.05), but a higher incidence of DGF (64 vs 39%, P < .05). One year graft loss (death censored) was comparable in the two groups. (4/42 vs. 3/33, P = .94). Resistance at 2, 4, and 6 hours was predictive of DGF, as was donor anoxia and cerebrovascular accident (CVA) as the cause of death. CONCLUSIONS: Kidneys on pulsatile pump perfusion tend to show improved flows and decreased resistance over time. The average flow for a kidney is reached by 2 hours. Those kidneys that start with lower flow rates that improve after 2 hours with continued perfusion are less likely to be discarded but are still associated with a greater incidence of delayed graft function. Resistance at 2 hours predicts DGF while initial resistance predicts one year graft survival.


Asunto(s)
Trasplante de Riñón , Perfusión , Donantes de Tejidos , Adulto , Humanos , Persona de Mediana Edad , Pronóstico
17.
Nano Lett ; 12(9): 4711-4, 2012 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-22827514

RESUMEN

We characterize nanostructures of Bi(2)Se(3) that are grown via metal-organic chemical vapor deposition using the precursors diethyl selenium and trimethyl bismuth. By adjusting growth parameters, we obtain either single-crystalline ribbons up to 10 µm long or thin micrometer-sized platelets. Four-terminal resistance measurements yield a sample resistivity of 4 mΩ·cm. We observe weak antilocalization and extract a phase coherence length l(ϕ) = 178 nm and spin-orbit length l(so) = 93 nm at T = 0.29 K. Our results are consistent with previous measurements on exfoliated samples and samples grown via physical vapor deposition.


Asunto(s)
Bismuto/química , Cristalización/métodos , Nanopartículas del Metal/química , Nanopartículas del Metal/ultraestructura , Compuestos Orgánicos/química , Selenio/química , Conductividad Eléctrica , Sustancias Macromoleculares/química , Ensayo de Materiales , Conformación Molecular , Tamaño de la Partícula , Gases em Plasma/química , Propiedades de Superficie
18.
Eur Heart J Cardiovasc Imaging ; 13(10): 827-33, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22736713

RESUMEN

AIMS: To assess the capacity of global longitudinal strain (GLS) in patients with aortic stenosis (AS) to (i) detect the subclinical left ventricular (LV) dysfunction [LV ejection fraction (LVEF) ≥50% patients]; (ii) predict all-cause mortality and major adverse cardiac events (MACE) (all patients), and (iii) provide incremental prognostic information over current risk markers. METHODS AND RESULTS: Patients with AS (n = 146) and age-matched controls (n = 12) underwent baseline echocardiography to assess AS severity, conventional LV parameters and GLS via speckle tracking echocardiography. Baseline demographics, symptom severity class and comorbidities were recorded. Outcomes were identified via hospital record review and subject/physician interview. The mean age was 75 ± 11, 62% were male. The baseline aortic valve (AV) area was 1.0 ± 0.4 cm(2) and LVEF was 59 ± 11%. In patients with a normal LVEF (n = 122), the baseline GLS was controls -21 ± 2%, mild AS -18 ± 3%, moderate AS -17 ± 3% and severe AS -15 ± 3% (P< 0.001). GLS correlated with the LV mass index, LVEF, AS severity, and symptom class (P< 0.05). During a median follow-up of 2.1 (inter-quartile range: 1.8-2.4) years, there were 20 deaths and 101 MACE. Unadjusted hazard ratios (HRs) for GLS (per %) were all-cause mortality (HR: 1.42, P< 0.001) and MACE (HR: 1.09, P< 0.001). After adjustment for clinical and echocardiographic variables, GLS remained a strong independent predictor of all-cause mortality (HR: 1.38, P< 0.001). CONCLUSIONS: GLS detects subclinical dysfunction and has incremental prognostic value over traditional risk markers including haemodynamic severity, symptom class, and LVEF in patients with AS. Incorporation of GLS into risk models may improve the identification of the optimal timing for AV replacement.


Asunto(s)
Estenosis de la Válvula Aórtica/mortalidad , Anciano , Anciano de 80 o más Años , Análisis de Varianza , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/patología , Biomarcadores , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Pronóstico , Estudios Prospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Volumen Sistólico , Ultrasonografía , Función Ventricular Izquierda , Victoria
19.
Exp Physiol ; 97(4): 477-85, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22198016

RESUMEN

Renin-angiotensin system blockade slows but does not prevent the cardiovascular complications of chronic kidney disease (CKD). Angiotensin-converting enzyme (ACE) 2 is differentially regulated in acute kidney injury, with increased cardiac ACE2 but decreased kidney ACE2 levels. This study investigated the effect of long-term ACE inhibition on cardiac and renal ACE2 in rats with CKD induced by subtotal nephrectomy (STNx). Sprague-Dawley rats had sham (control) or STNx surgery. Control rats received vehicle (n = 9) and STNx rats ramipril (1 mg kg(-1) day(-1); n = 10) or vehicle (n = 10) for 28 days. Subtotal nephrectomy resulted in impaired creatinine clearance (P < 0.05), proteinuria (P < 0.05), renal fibrosis (P < 0.05) and reduced renal cortical ACE2 mRNA (P < 0.05) and activity (P < 0.05). In rats with CKD, ramipril improved creatinine clearance (P < 0.05) and was associated with an increase in cortical but not medullary ACE2 activity (P < 0.05). Compared with control rats, STNx rats were hypertensive (P < 0.01), with increased left ventricular end-diastolic pressure (LVEDP; P < 0.01), left ventricular hypertrophy (LVH; P < 0.05) and interstitial (P < 0.05) and perivascular fibrosis (P < 0.01). In rats with CKD, ramipril decreased blood pressure (P < 0.001) and reduced LVEDP (P < 0.01), LVH (P < 0.01) and perivascular fibrosis (P < 0.05) but did not significantly reduce interstitial fibrosis. There was no change in cardiac ACE2 in rats with CKD compared with control rats. In rats with CKD, ACE inhibition had major benefits to reduce blood pressure and cardiac hypertrophy and to improve creatinine clearance, but did not significantly impact on cardiac ACE2, cardiac interstitial fibrosis, renal fibrosis or proteinuria. Thus, in rats with CKD, renal ACE2 deficiency and lack of activation of cardiac ACE2 may contribute to the progression of cardiac and renal tissue injury. As long-term ACE inhibition only partly ameliorated the adverse cardio-renal effects of CKD, adjunctive therapies that lead to further increases in ACE2 activity may be needed to combat the cardio-renal complications of CKD.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Regulación Enzimológica de la Expresión Génica , Fallo Renal Crónico/tratamiento farmacológico , Fallo Renal Crónico/enzimología , Miocardio/patología , Nefrectomía , Peptidil-Dipeptidasa A/biosíntesis , Peptidil-Dipeptidasa A/deficiencia , Enzima Convertidora de Angiotensina 2 , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Animales , Hipertensión/tratamiento farmacológico , Hipertensión/enzimología , Hipertrofia Ventricular Izquierda/tratamiento farmacológico , Hipertrofia Ventricular Izquierda/enzimología , Miocardio/metabolismo , Peptidil-Dipeptidasa A/genética , Ramipril/farmacología , Ramipril/uso terapéutico , Ratas , Ratas Sprague-Dawley , Resultado del Tratamiento
20.
AJNR Am J Neuroradiol ; 32(9): 1640-5, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21799045

RESUMEN

BACKGROUND AND PURPOSE: The regional leptomeningeal score is a strong and reliable imaging predictor of good clinical outcomes in acute anterior circulation ischemic strokes and can therefore be used for imaging based patient selection. Efforts to determine biological determinants of collateral status are needed if techniques to alter collateral behavior and extend time windows are to succeed. MATERIALS AND METHODS: This was a retrospective Institutional Review Board-approved study of patients with acute ischemic stroke and M1 middle cerebral artery+/- intracranial internal carotid artery occlusion at our center from 2003 to 2009. The rLMC score is based on scoring pial and lenticulostriate arteries (0, no; 1, less; 2, equal or more prominent compared with matching region in opposite hemisphere) in 6 ASPECTS regions (M1-6) plus anterior cerebral artery region and basal ganglia. Pial arteries in the Sylvian sulcus are scored 0, 2, or 4. Good clinical outcome was defined as mRS ≤ 2 at 90 days. RESULTS: The analysis included 138 patients: 37.6% had a good (17-20), 40.5% a medium (11-16), and 21.7% a poor (0-10) rLMC score. Interrater reliability was high, with an intraclass correlation coefficient of 0.87 (95% CI, 0.77%-0.95%). On univariate analysis, no single vascular risk factor was associated with the presence of poor rLMCs (P ≥ .20 for all comparisons). In multivariable analysis, the rLMC score (good versus poor: OR, 16.7; 95% CI, 2.9%-97.4%; medium versus poor: OR, 9.2, 95% CI, 1.7%-50.6%), age (< 80 years), baseline ASPECTS (≥ 8), and clot burden score (≥ 8) were independent predictors of good clinical outcome. CONCLUSIONS: The rLMC score is a strong imaging parameter on CT angiography for predicting clinical outcomes in patients with acute ischemic strokes.


Asunto(s)
Isquemia Encefálica/diagnóstico por imagen , Angiografía Cerebral/métodos , Infarto de la Arteria Cerebral Anterior/diagnóstico por imagen , Infarto de la Arteria Cerebral Media/diagnóstico por imagen , Meninges/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Enfermedad Aguda , Angiografía Cerebral/normas , Angiografía Cerebral/estadística & datos numéricos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Meninges/irrigación sanguínea , Variaciones Dependientes del Observador , Piamadre/irrigación sanguínea , Piamadre/diagnóstico por imagen , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Estudios Retrospectivos , Tomografía Computarizada por Rayos X/normas , Tomografía Computarizada por Rayos X/estadística & datos numéricos
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