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1.
Climacteric ; 21(1): 53-59, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29189095

RESUMEN

OBJECTIVE: This study examined relationships, by pregnancy histories, between bone mineral density (BMD) and coronary artery calcification (CAC) in postmenopausal women. METHODS: Forty women identified from their medical record as having pre-eclampsia (PE) were age/parity-matched with 40 women having a normotensive pregnancy (NP). Vertebral (T4-9) BMD and CAC were assessed by quantitative computed tomography in 73 (37 with PE and 36 with NP) of the 80 women. Analyses included linear regression using generalized estimating equations. RESULTS: Women averaged 59 years of age and 35 years from the index pregnancy. There were no significant differences in cortical, trabecular or central BMD between groups. CAC was significantly greater in the PE group (p = 0.026). In multivariable analysis, CAC was positively associated with cortical BMD (p = 0.001) and negatively associated with central BMD (p = 0.036). There was a borderline difference in the association between CAC and central BMD by pregnancy history (interaction, p = 0.057). CONCLUSIONS: Although CAC was greater in women with a history of PE, vertebral BMD did not differ between groups. However, both cortical and central BMD were associated with CAC. The central BMD association was marginally different by pregnancy history, suggesting perhaps differences in underlying mechanisms of soft tissue calcification.


Asunto(s)
Enfermedad de la Arteria Coronaria/complicaciones , Osteoporosis/complicaciones , Preeclampsia , Historia Reproductiva , Calcificación Vascular/diagnóstico por imagen , Absorciometría de Fotón , Densidad Ósea , Enfermedad de la Arteria Coronaria/epidemiología , Femenino , Humanos , Modelos Lineales , Menopausia , Persona de Mediana Edad , Minnesota/epidemiología , Análisis Multivariante , Osteoporosis/epidemiología , Embarazo , Factores de Riesgo , Tomografía Computarizada por Rayos X
2.
Mol Psychiatry ; 23(5): 1233-1243, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-28322273

RESUMEN

Numerous genetic and functional studies implicate variants of Neuregulin-1 (NRG1) and its neuronal receptor ErbB4 in schizophrenia and many of its endophenotypes. Although the neurophysiological and behavioral phenotypes of NRG1 mutant mice have been investigated extensively, practically nothing is known about the function of NRG2, the closest NRG1 homolog. We found that NRG2 expression in the adult rodent brain does not overlap with NRG1 and is more extensive than originally reported, including expression in the striatum and medial prefrontal cortex (mPFC), and therefore generated NRG2 knockout mice (KO) to study its function. NRG2 KOs have higher extracellular dopamine levels in the dorsal striatum but lower levels in the mPFC; a pattern with similarities to dopamine dysbalance in schizophrenia. Like ErbB4 KO mice, NRG2 KOs performed abnormally in a battery of behavioral tasks relevant to psychiatric disorders. NRG2 KOs exhibit hyperactivity in a novelty-induced open field, deficits in prepulse inhibition, hypersensitivity to amphetamine, antisocial behaviors, reduced anxiety-like behavior in the elevated plus maze and deficits in the T-maze alteration reward test-a task dependent on hippocampal and mPFC function. Acute administration of clozapine rapidly increased extracellular dopamine levels in the mPFC and improved alternation T-maze performance. Similar to mice treated chronically with N-methyl-d-aspartate receptor (NMDAR) antagonists, we demonstrate that NMDAR synaptic currents in NRG2 KOs are augmented at hippocampal glutamatergic synapses and are more sensitive to ifenprodil, indicating an increased contribution of GluN2B-containing NMDARs. Our findings reveal a novel role for NRG2 in the modulation of behaviors with relevance to psychiatric disorders.


Asunto(s)
Dopamina/metabolismo , Trastornos Mentales/metabolismo , Factores de Crecimiento Nervioso/deficiencia , Animales , Conducta Animal/fisiología , Encéfalo/metabolismo , Clozapina/farmacología , Dopamina/genética , Receptores ErbB/metabolismo , Masculino , Trastornos Mentales/genética , Ratones , Ratones Noqueados , Factores de Crecimiento Nervioso/genética , Factores de Crecimiento Nervioso/metabolismo , Neurregulina-1/genética , Neurregulina-1/metabolismo , Receptor ErbB-4/genética , Receptor ErbB-4/metabolismo , Transducción de Señal , Sinapsis/metabolismo , Transcriptoma
3.
Climacteric ; 18(2): 187-97, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25417709

RESUMEN

OBJECTIVE: Endothelial dysfunction occurs early in the atherosclerotic disease process, often preceding clinical symptoms. Use of menopausal hormone treatment (MHT) to reduce cardiovascular risk is controversial. This study evaluated effects of 4 years of MHT on endothelial function in healthy, recently menopausal women. METHODS: Endothelial function was determined by pulse volume digital tonometry providing a reactive hyperemia index (RHI) in a subset of women enrolled in the Kronos Early Estrogen Prevention Study. RHI was measured before and annually after randomization to daily oral conjugated equine estrogen (oCEE, 0.45 mg), weekly transdermal 17ß-estradiol (tE2, 50 µg) each with intermittent progesterone (200 mg daily 12 days of the month) or placebo pills and patch. RESULTS: At baseline, RHI averaged 2.39 ± 0.69 (mean ± standard deviation; n = 83), and over follow-up did not differ significantly among groups: oCEE, 2.26 ± 0.48 (n = 26); tE2, 2.26 ± 0.45 (n = 24); and placebo, 2.37 ± 0.37 (n = 33). Changes in RHI did not correlate with changes in traditional cardiovascular risk factors, but may inversely correlate with carotid intima medial thickness (Spearman correlation coefficient ρ = -0.268, p = 0.012). CONCLUSION: In this 4-year prospective assessment of recently menopausal women, MHT did not significantly alter RHI when compared to placebo.


Asunto(s)
Enfermedades Cardiovasculares/prevención & control , Endotelio Vascular/fisiología , Terapia de Reemplazo de Estrógeno , Menopausia/fisiología , Administración Cutánea , Administración Oral , Adulto , Endotelio Vascular/efectos de los fármacos , Estradiol/administración & dosificación , Estrógenos Conjugados (USP)/administración & dosificación , Femenino , Humanos , Hiperemia , Persona de Mediana Edad , Placebos , Progesterona/administración & dosificación , Estudios Prospectivos
4.
J Intern Med ; 276(5): 486-97, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24612202

RESUMEN

OBJECTIVE: Elevations in uric acid (UA) and the associated hyperuricaemia are commonly observed secondary to treatment with thiazide diuretics. We sought to identify novel single nucleotide polymorphisms (SNPs) associated with hydrochlorothiazide (HCTZ)-induced elevations in UA and hyperuricaemia. METHODS: A genome-wide association study of HCTZ-induced changes in UA was performed in Caucasian and African American participants from the pharmacogenomic evaluation of antihypertensive responses (PEAR) study who were treated with HCTZ monotherapy. Suggestive SNPs were replicated in Caucasians and African Americans from the PEAR study who were treated with HCTZ add-on therapy. Replicated regions were followed up through expression and pathway analysis. RESULTS: Five unique gene regions were identified in African Americans (LUC7L2, ANKRD17/COX18, FTO, PADI4 and PARD3B), and one region was identified in Caucasians (GRIN3A). Increases in UA of up to 1.8 mg dL(-1) were observed following HCTZ therapy in individuals homozygous for risk alleles, with heterozygotes displaying an intermediate phenotype. Several risk alleles were also associated with an increased risk of HCTZ-induced clinical hyperuricaemia. A composite risk score, constructed in African Americans using the 'top' SNP from each gene region, was strongly associated with HCTZ-induced UA elevations (P = 1.79 × 10(-7) ) and explained 11% of the variability in UA response. Expression studies in RNA from whole blood revealed significant differences in expression of FTO by rs4784333 genotype. Pathway analysis showed putative connections between many of the genes identified through common microRNAs. CONCLUSION: Several novel gene regions were associated with HCTZ-induced UA elevations in African Americans (LUC7L2, COX18/ANKRD17, FTO, PADI4 and PARD3B), and one region was associated with these elevations in Caucasians (GRIN3A).


Asunto(s)
Antihipertensivos/efectos adversos , Negro o Afroamericano/genética , Diuréticos/efectos adversos , Hidroclorotiazida/efectos adversos , Hiperuricemia/inducido químicamente , Hiperuricemia/genética , Polimorfismo de Nucleótido Simple , Población Blanca/genética , Adulto , Femenino , Estudio de Asociación del Genoma Completo , Genotipo , Humanos , Hipertensión/sangre , Hipertensión/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Farmacogenética , Factores de Riesgo
5.
J Thromb Haemost ; 11(7): 1279-86, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23648016

RESUMEN

BACKGROUND: The incidence of symptomatic venous thromboembolism (VTE) after knee arthroscopy is uncertain. OBJECTIVES: To estimate the incidence of symptomatic VTE after arthroscopic knee surgery. METHODS: In a population-based historical cohort study, all Olmsted County, MN, USA, residents undergoing a first arthroscopic knee surgery during the 18-year period of 1988-2005 were followed for incident deep venous thrombosis or pulmonary embolism. The cumulative incidence of VTE after knee arthroscopy was determined using the Kaplan-Meier product limit estimator. Patient age at surgery, sex, calendar year of surgery, body mass index, anesthesia characteristics, and hospitalization were tested as potential predictors of VTE using Cox proportional hazards modeling, both univariately and adjusted for age and sex. RESULTS: Among 4833 Olmsted County residents with knee arthroscopy, 18 developed postoperative VTE, all within the first 6 weeks after surgery. The cumulative incidence rates of symptomatic VTE at 7, 14, and 35 days were 0.2%, 0.3%, and 0.4%, respectively. The hazard for postoperative VTE was significantly increased for older patient age (hazard ratio = 1.34 for each 10-year increase in patient age; P = 0.03) and hospitalization either before or after knee arthroscopy (hazard ratio = 14.1; P < 0.001). CONCLUSIONS: The incidence of symptomatic VTE after arthroscopic knee surgery is very low. Older age and hospitalization are associated with increased risk. Routine prophylaxis to prevent symptomatic VTE is likely not needed in this patient population.


Asunto(s)
Artroscopía/efectos adversos , Articulación de la Rodilla/cirugía , Tromboembolia Venosa/epidemiología , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Procedimientos Quirúrgicos Electivos , Femenino , Hospitalización , Humanos , Incidencia , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Minnesota/epidemiología , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Tromboembolia Venosa/prevención & control , Adulto Joven
6.
Pharmacogenomics J ; 13(3): 257-63, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22350108

RESUMEN

A recent genome-wide analysis discovered an association between a haplotype (from rs317689/rs315135/rs7297610) on Chromosome 12q15 and blood pressure response to hydrochlorothiazide (HCTZ) in African-Americans. Our aim was to replicate this association and investigate possible functional mechanisms. We observed similar associations between this haplotype and HCTZ response in an independent sample of 746 Caucasians and African-Americans randomized to HCTZ or atenolol treatment. The haplotype association was driven by variation at rs7297610, where C/C genotypes were associated with greater mean (systolic: 3.4 mmHg, P=0.0275; diastolic: 2.5 mmHg, P=0.0196) responses to HCTZ vs T-allele carriers. Such an association was absent in atenolol-treated participants, supporting this as HCTZ specific. Expression analyses in HCTZ-treated African-Americans showed differential pre-treatment leukocyte YEATS4 expression between rs7297610 genotype groups (P=0.024), and reduced post-treatment expression in C/C genotypes (P=0.009), but not in T-carriers. Our data confirm previous genome-wide findings at 12q15 and suggest differential YEATS4 expression could underpin rs7297610-associated HCTZ response variability, which may have future implications for guiding thiazide treatment.


Asunto(s)
Estudio de Asociación del Genoma Completo , Hidroclorotiazida/administración & dosificación , Hipertensión/genética , Factores de Transcripción/genética , Adulto , Negro o Afroamericano/genética , Antihipertensivos/administración & dosificación , Atenolol , Presión Sanguínea/genética , Cromosomas Humanos Par 12/genética , Ensayos Clínicos como Asunto , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica/genética , Genotipo , Haplotipos , Humanos , Hipertensión/tratamiento farmacológico , Hipertensión/patología , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Población Blanca/genética
7.
Pharmacogenomics J ; 13(5): 430-6, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22907731

RESUMEN

Thiazide-induced potassium loss may contribute to new onset diabetes (NOD). KCNJ1 encodes a potassium channel and one study observed that a KCNJ1 single-nucleotide polymorphism (SNP) was associated with changes in fasting glucose (FG) during hydrochlorothiazide (HCTZ) treatment. We used linear regression to test association of KCNJ1 SNPs and haplotypes with FG changes during HCTZ treatment in the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) study. We used logistic regression to test association of KCNJ1 variation with NOD in HCTZ-treated patients from the International Verapamil SR Trandolapril Study (INVEST). Multivariate regression analyses were performed by race/ethnicity with false discovery rate (FDR) correction. In PEAR blacks, a KCNJ1 SNP was associated with increased FG during HCTZ treatment (beta=8.47, P(FDR)=0.009). KCNJ1 SNPs and haplotypes were associated with NOD risk in all INVEST race/ethnic groups (strongest association: odds ratio 2.14 (1.31-3.53), P(FDR)=0.03). Our findings support that KCNJ1 variation is associated with HCTZ-induced dysglycemia and NOD.


Asunto(s)
Antihipertensivos/uso terapéutico , Diabetes Mellitus/genética , Diabetes Mellitus/metabolismo , Ayuno/metabolismo , Glucosa/metabolismo , Hidroclorotiazida/uso terapéutico , Polimorfismo de Nucleótido Simple/genética , Canales de Potasio de Rectificación Interna/genética , Anciano , Atenolol/uso terapéutico , Diabetes Mellitus/tratamiento farmacológico , Femenino , Haplotipos , Humanos , Masculino , Persona de Mediana Edad , Farmacogenética/métodos , Canales de Potasio de Rectificación Interna/metabolismo , Estudios Prospectivos , Verapamilo/uso terapéutico
8.
Climacteric ; 13(1): 45-54, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19657788

RESUMEN

BACKGROUND: Peripheral arterial, endothelium-dependent, flow-mediated reactive hyperemia is reduced in individuals with atherosclerosis. This study tested the hypothesis that digital tonometry, as a surrogate of endothelial function, is useful to stratify cardiovascular risk in recently menopausal women who are asymptomatic for cardiovascular disease. METHODS: Women undergoing screening for the Kronos Early Estrogen Prevention Study (KEEPS) were evaluated for conventional risk factors, flow-mediated reactive hyperemia by digital tonometry (RHI), carotid intima-media thickness (CIMT) by ultrasound, and coronary arterial calcium (CAC) by 64-slice CT scanner. RESULTS: One hundred and two non-diabetic Caucasian women (53.0 +/- 2.3 years old, 18.0 +/- 9.0 months past their last menses) participated; 72% were never-smokers. Fourteen women had positive CAC scores (range 0.5-133 Agatston units); CIMT ranged from 0.57 to 1.06 mm. RHI ranged from 1.26 to 5.44. RHI did not correlate with time past menopause, CAC, CIMT, total cholesterol or low density lipoprotein cholesterol. The significant negative correlation of RHI with body mass index (r = -0.21, p = 0.031) was lost in non-smokers (r = - 0.17, p = 0.14). There was also a negative correlation of high density lipoprotein cholesterol with CAC, both in the overall group and non-smokers (rho = -0.20, p = 0.05 and rho = -0.27, p = 0.02, respectively). CONCLUSIONS: RHI varies widely in healthy women within the first 3 years of menopause. RHI was not associated with standard risk assessment algorithms, CAC or CIMT. RHI may indicate an additional, independent component and non-invasive tool to further stratify cardiovascular risk in recently menopausal women. As KEEPS continues, data on RHI will provide information regarding hormonal therapy, endovascular biology and atherosclerotic risk.


Asunto(s)
Enfermedades Cardiovasculares/epidemiología , Endotelio Vascular/fisiopatología , Menopausia/fisiología , Calcio/análisis , Enfermedades Cardiovasculares/fisiopatología , Arterias Carótidas/diagnóstico por imagen , Colesterol/sangre , LDL-Colesterol/sangre , Vasos Coronarios/química , Método Doble Ciego , Femenino , Humanos , Hiperemia/diagnóstico , Hiperemia/epidemiología , Lípidos/sangre , Persona de Mediana Edad , Medición de Riesgo/métodos , Túnica Íntima/diagnóstico por imagen , Túnica Media/diagnóstico por imagen , Ultrasonografía
9.
Clin Pharmacol Ther ; 86(5): 533-9, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19571804

RESUMEN

For combination antihypertensive therapy with thiazide diuretics and beta-blockers, the effect of the order of initiation of the drugs on the outcome has not been tested. Patients with uncomplicated hypertension were randomized to receive either hydrochlorothiazide (HCTZ) or atenolol monotherapy, followed by addition of the alternative drug. Blood pressure (BP) responses were evaluated by race and order of drug initiation. A total of 368 participants received combination therapy. Among the participants, blacks showed a greater BP-lowering effect than whites did with HCTZ monotherapy (-13.0/-7.4 mm Hg vs. -8.0/-4.2 mm Hg, P < 0.001) but a smaller BP-lowering effect than did whites with atenolol monotherapy (-1.1/-2.9 mm Hg vs. -9.9/-9.2 mm Hg, P < 0.0001). These differences were not evident during combination therapy. However, both groups showed greater response to HCTZ + atenolol than to atenolol + HCTZ (-19.1/-14.2 mm Hg vs. -15.6/-11.3 mm Hg, P < 0.0001). Despite optimal dosing of HCTZ + atenolol, only two-thirds of the participants achieved BP control. In HCTZ/atenolol combination antihypertensive therapy, the order in which the drugs are initiated affects total BP lowering during the first 4-6 months of therapy.


Asunto(s)
Antihipertensivos/uso terapéutico , Atenolol/uso terapéutico , Presión Sanguínea/efectos de los fármacos , Hidroclorotiazida/uso terapéutico , Hipertensión/tratamiento farmacológico , Adulto , Antihipertensivos/administración & dosificación , Atenolol/administración & dosificación , Población Negra , Esquema de Medicación , Quimioterapia Combinada , Femenino , Estudios de Seguimiento , Humanos , Hidroclorotiazida/administración & dosificación , Hipertensión/fisiopatología , Masculino , Persona de Mediana Edad , Población Blanca
10.
Br J Ophthalmol ; 93(8): 1116-20, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19304587

RESUMEN

AIMS: Excessive lipid accumulation in Bruch's membrane (BrM) is a hallmark of ageing, the major risk factor for age-related macular degeneration (AMD). Retinal pigment epithelial (RPE) cells may utilise reverse cholesterol transport (RCT) activity to move lipid into BrM, mediated through ATP-binding cassette A1 (ABCA1) and scavenger receptor BI (SR-BI). METHODS: ABCA1 expression was assessed by reverse transcription polymerase chain reaction (RT-PCR) and western blotting of human RPE cell extracts. Lipid transport assays were performed using radiolabelled photoreceptor outer segments (POS). ABCA1 and SR-BI expression was examined in normal mouse eyes by immunofluorescence staining. BrMs of ABCA1 and SR-BI heterozygous mice were examined microscopically. RESULTS: Human RPE cells expressed ABCA1 mRNA and protein. The ABCA1 and SR-BI inhibitor glyburide (also known as glibenclamide) abolished basal transport of POS-derived lipids in RPE cells in the presence of high-density lipoprotein. Mouse retina and RPE expressed ABCA1 and SR-BI. SR-BI was highly expressed in RPE. BrMs were significantly thickened in SR-BI heterozygous mice, but not in ABCA1 heterozygous mice. CONCLUSION: RPE cells express ABCA1 and SR-BI. This implies a significant role for SR-BI and ABCA1 in lipid transport and RCT in the retina and RPE.


Asunto(s)
Transportadoras de Casetes de Unión a ATP/metabolismo , Retina/metabolismo , Receptores Depuradores de Clase B/metabolismo , Transportador 1 de Casete de Unión a ATP , Transportadoras de Casetes de Unión a ATP/genética , Adulto , Animales , Lámina Basal de la Coroides/ultraestructura , Células Cultivadas , Electrorretinografía , Proteínas del Ojo/metabolismo , Expresión Génica , Humanos , Metabolismo de los Lípidos , Ratones , Ratones Mutantes , Microscopía Electrónica , ARN Mensajero/genética , Retina/fisiología , Epitelio Pigmentado de la Retina/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos
11.
J Hum Hypertens ; 23(8): 530-7, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19190656

RESUMEN

Haemostatic markers have been implicated in the development and progression of vascular disease. We investigated the associations of several haemostatic markers (fibrinogen, D-dimer, FV, FVII, FVIII, von Willebrand factor (vWF) and antithrombin III) with two quantitative measures of vascular disease in adults with hypertension. Participants included 1051 African Americans (65+/-9 years, 72% women) and 894 non-Hispanic whites (61+/-9 years, 55% women) belonging to hypertensive sibships. Phenotypes of vascular disease included the ankle-brachial index (ABI), a measure of peripheral arterial disease, and urinary albumin/creatinine ratio (UACR), a surrogate of glomerular endothelial function. Generalized estimating equations were used to assess whether plasma levels of haemostatic markers were associated with measures of arteriosclerosis, after adjustment for conventional risk factors and medication (statin, aspirin and oestrogen) use. Higher fibrinogen and D-dimer were significantly associated with lower ABI in African Americans (P<0.001 and 0.004 respectively) and in non-Hispanic whites (P<0.001 and 0.010 respectively). Higher fibrinogen (P<0.001), D-dimer (P=0.003), FVIII (P<0.001) and vWF (P<0.001) were significantly associated with higher UACR in African Americans, whereas, in non-Hispanic whites, higher fibrinogen (P=0.020) and FVII (P=0.006) were significantly associated with higher UACR. Our findings indicate that in adults with essential hypertension, several markers in the haemostatic pathway are independently associated with ABI and UACR, two measures of vascular disease..


Asunto(s)
Arteriosclerosis/sangre , Aterosclerosis/sangre , Biomarcadores/sangre , Hipertensión/sangre , Negro o Afroamericano , Anciano , Albuminuria/orina , Índice Tobillo Braquial , Antitrombina III/metabolismo , Arteriosclerosis/diagnóstico , Arteriosclerosis/etnología , Aterosclerosis/diagnóstico , Aterosclerosis/etnología , Creatinina/orina , Factor V/metabolismo , Factor VII/metabolismo , Factor VIII/metabolismo , Femenino , Productos de Degradación de Fibrina-Fibrinógeno/metabolismo , Fibrinógeno/metabolismo , Humanos , Hipertensión/diagnóstico , Hipertensión/etnología , Masculino , Persona de Mediana Edad , Población Blanca , Factor de von Willebrand/metabolismo
12.
Br J Ophthalmol ; 90(5): 616-20, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-16622093

RESUMEN

BACKGROUND/AIM: [corrected] The transport of radiolabelled photoreceptor outer segments (POS) lipids was investigated by cultured retinal pigment epithelial cells (RPE). Phagocytosis of POS by the RPE is essential to maintain the health and function of the photoreceptors in vivo. POS are phagocytised at the apical cell surface of RPE cells. Phagocytised POS lipids may be either recycled to the photoreceptors for reincorporation into new POS or they may be transported to the basolateral surface for efflux into the circulation. RESULTS: The authors have demonstrated that high density lipoprotein (HDL) stimulates efflux of radiolabelled lipids, of POS origin, from the basal surface of RPE cells in culture. Effluxed lipids bind preferentially to HDL species of low and high molecular weight. Effluxed radiolabelled phosphotidyl choline was the major phospholipid bound to HDL, with lesser amounts of phosphatidyl ethanolamine, phosphatidyl inosotol. Effluxed radiolabelled triglycerides, cholesterol, and cholesterol esters also bound to HDL. Lipid free apolipoprotein A-I (apoA-I) and apoA-I containing vesicles also stimulate lipid efflux. CONCLUSION: The findings suggest a role for HDL and apoA-I in regulating lipid and cholesterol transport from RPE cells that may influence the pathological lipid accumulation associated with age related macular degeneration.


Asunto(s)
Células Epiteliales/metabolismo , Metabolismo de los Lípidos , Lipoproteínas HDL/metabolismo , Epitelio Pigmentado Ocular/metabolismo , Adulto , Apolipoproteína A-I/metabolismo , Transporte Biológico , Células Cultivadas , Cromatografía en Capa Delgada , Humanos , Lípidos/análisis , Masculino , Fosfatidilcolinas/análisis , Fosfatidilcolinas/metabolismo , Fosfatidiletanolaminas/análisis , Fosfatidiletanolaminas/metabolismo , Fosfatidilinositoles/análisis , Fosfatidilinositoles/metabolismo , Radioisótopos , Segmento Externo de la Célula en Bastón/metabolismo
13.
Cereb Cortex ; 14(9): 974-85, 2004 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15084497

RESUMEN

Frontal cortex controls voluntary movement through projections to striatum that continue as parallel pallido-thalamic loops. In previous studies we found evidence of a double dissociation in rat striatum between visuospatial response time (RT) and radial maze delayed non-matching (DNM) tasks. Here we compare the effects of frontal cortical lesions on these tasks. We found that lesions involving sensorimotor areas in dorsolateral cortex affect RT for responding to visuospatial stimuli without affecting other measures of response speed or producing signs of attentional or sensory impairment. These deficits were equivalent to impairments observed with lesions in sensorimotor areas of dorsolateral striatum. Dorsal prefrontal lesions produced RT deficits indicative of attentional impairment that have not been observed with striatal or thalamic lesions. This suggests contributions of prefrontal cortex to attention independent of striatum and thalamus. Prefrontal lesions had significant but circumscribed effects on DNM consistent with effects of lesions in anatomically related areas of striatum or thalamus observed in earlier studies. These results are consistent with evidence implicating prefrontal cortex in aspects of spatial memory mediated by anatomically related pathways in the basal ganglia and thalamus.


Asunto(s)
Atención/fisiología , Lóbulo Frontal/fisiología , Memoria/fisiología , Desempeño Psicomotor/fisiología , Conducta Espacial/fisiología , Animales , Femenino , Masculino , Estimulación Luminosa/métodos , Ratas , Ratas Long-Evans , Tiempo de Reacción/fisiología
14.
Am J Med ; 111(6): 433-8, 2001 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-11690567

RESUMEN

PURPOSE: To determine the incidence of thromboembolic complications after cardioversion in patients with atrial flutter. SUBJECTS AND METHODS: We reviewed 615 electrical cardioversions performed electively in 493 patients with atrial flutter. Embolic complications were evaluated during the 30 days after cardioversion. Follow-up data were obtained by follow-up visits and by contacting the treating physician. RESULTS: Anticoagulants had been administered in 415 cardioversions (67%). Cardioversion was successful in 570 procedures (93%). Three embolic events (in 3 patients) occurred in the 30 days after 550 successful cardioversions with completed follow-up (0.6% of successful procedures; 95% confidence interval, 0.1% to 1.6%). Two of the 3 patients had not been anticoagulated, whereas the third patient had subtherapeutic oral anticoagulation. No embolic event occurred in procedures performed with adequate anticoagulation. The incidence of embolism in patients regardless of subtherapeutic anticoagulation was 1% (3 of 303 successful cardioversions). CONCLUSIONS: We observed a low (0.6%) incidence of postcardioversion thromboembolic complications in patients with atrial flutter. Embolic events did not occur in patients with adequate anticoagulation.


Asunto(s)
Aleteo Atrial/terapia , Cardioversión Eléctrica/efectos adversos , Tromboembolia/etiología , Tromboembolia/fisiopatología , Administración Oral , Anciano , Anciano de 80 o más Años , Anticoagulantes/administración & dosificación , Anticoagulantes/uso terapéutico , Aleteo Atrial/diagnóstico por imagen , Aleteo Atrial/fisiopatología , Femenino , Estudios de Seguimiento , Heparina/uso terapéutico , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias , Estudios Retrospectivos , Factores de Riesgo , Tromboembolia/diagnóstico por imagen , Ultrasonografía
15.
Mayo Clin Proc ; 76(11): 1111-9, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11702899

RESUMEN

OBJECTIVES: To determine levels of natriuretic peptides (NPs) in patients with end-stage renal disease (ESRD) and to examine the relationship of these cardiovascular peptides to left ventricular hypertrophy (LVH) and to cardiac mortality. PATIENTS AND METHODS: One hundred twelve dialysis patients without clinical evidence of congestive heart failure underwent plasma measurement of NP concentrations and echocardiographic investigation for left ventricular mass index (LVMI). RESULTS: Plasma atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) concentrations correlated positively with LVMI and inversely with left ventricular ejection fraction, whereas C-type NP and Dendroaspis NP levels did not correlate with LVMI. In dialysis patients with LVH (LVMI >125 g/m2), plasma ANP and BNP concentrations were increased compared with those in dialysis patients without LVH (both P<001). In a subset of 15 dialysis patients without LVH or other concomitant diseases, plasma BNP concentrations were not significantly increased compared with those in 35 controls (mean +/- SD, 20.1+/-13.4 vs 13.5+/-9.6 pg/mL; P=.06), demonstrating that the BNP concentration was not increased by renal dysfunction alone. Furthermore, the BNP level was significantly higher in the 16 patients who died from cardiovascular causes compared with survivors (mean +/- SD, 129+/-13 vs 57+/-7 pg/mL; P<.003) and was significantly associated with greater risk of cardiovascular death in Cox regression analysis (P<.001), as was the ANP level (P=.002). CONCLUSIONS: Elevation of the plasma BNP concentration is more specifically related to LVH compared with the other NP levels in patients with ESRD independent of congestive heart failure. Thus, BNP serves as an important plasma biomarker for ventricular hypertrophy in dialysis patients with ESRD.


Asunto(s)
Factor Natriurético Atrial/sangre , Hipertrofia Ventricular Izquierda/sangre , Fallo Renal Crónico/sangre , Péptido Natriurético Encefálico/fisiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores , Estudios de Casos y Controles , Comorbilidad , Femenino , Hemodinámica , Humanos , Fallo Renal Crónico/etiología , Modelos Lineales , Masculino , Persona de Mediana Edad , Péptido Natriurético Encefálico/sangre , Curva ROC , Diálisis Renal , Factores de Riesgo
16.
N Engl J Med ; 345(14): 1022-9, 2001 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-11586954

RESUMEN

BACKGROUND: Circulating markers indicating the instability of atherosclerotic plaques could have diagnostic value in unstable angina or acute myocardial infarction. We evaluated pregnancy-associated plasma protein A (PAPP-A), a potentially proatherosclerotic metalloproteinase, as a marker of acute coronary syndromes. METHODS: We examined the level of expression of PAPP-A in eight culprit unstable coronary plaques and four stable plaques from eight patients who had died suddenly of cardiac causes. We also measured circulating levels of PAPP-A, C-reactive protein, and insulin-like growth factor I (IGF-I) in 17 patients with acute myocardial infarction, 20 with unstable angina, 19 with stable angina, and 13 controls without atherosclerosis. RESULTS: PAPP-A was abundantly expressed in plaque cells and extracellular matrix of ruptured and eroded unstable plaques, but not in stable plaques. Circulating PAPP-A levels were significantly higher in patients with unstable angina or acute myocardial infarction than in patients with stable angina and controls (P<0.001). A PAPP-A threshold value of 10 mlU per liter identified patients who had acute coronary syndromes with a sensitivity of 89.2 percent and a specificity of 81.3 percent. PAPP-A levels correlated with levels of C-reactive protein and free IGF-I, but not with markers of myocardial injury (troponin I and the MB isoform of creatine kinase). CONCLUSIONS: PAPP-A is present in unstable plaques, and circulating levels are elevated in acute coronary syndromes; these increased levels may reflect the instability of atherosclerotic plaques. PAPP-A is a new candidate marker of unstable angina and acute myocardial infarction.


Asunto(s)
Angina Inestable/sangre , Infarto del Miocardio/sangre , Proteína Plasmática A Asociada al Embarazo/análisis , Anciano , Angina de Pecho/sangre , Angina Inestable/diagnóstico , Biomarcadores/análisis , Biomarcadores/sangre , Proteína C-Reactiva/análisis , Estudios de Casos y Controles , Enfermedad de la Arteria Coronaria/diagnóstico , Enfermedad de la Arteria Coronaria/patología , Vasos Coronarios/patología , Muerte Súbita Cardíaca , Femenino , Humanos , Factor I del Crecimiento Similar a la Insulina/análisis , Masculino , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico , Miocardio/patología , Pronóstico , Análisis de Regresión
17.
J Am Soc Echocardiogr ; 14(10): 978-86, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11593202

RESUMEN

Systolic and especially diastolic Doppler time intervals may be early markers of myocardial ischemia inducible by dobutamine-atropine stress echocardiography (DASE). We postulated that the Doppler myocardial performance index (MPI) may help differentiate ischemic from nonischemic responses. Hemodynamic and Doppler echocardiography variables were measured prospectively at every stress level of DASE in 32 patients (mean age 67 +/- 13 years). Adequate recordings were obtained in 27 patients; 13 had an ischemic response (group I) and 14 a nonischemic response (group II). Heart rate differed between groups at baseline. At equivalent peak stress, left ventricular wall motion score index was significantly greater and ejection fraction lower in group I patients. Of the Doppler variables, only the MPI consistently differed between groups, irrespective of the number of stress levels compared. The Doppler MPI may be a useful adjunct to wall motion analysis in the detection of myocardial ischemia during DASE.


Asunto(s)
Presión Sanguínea , Ecocardiografía Doppler , Prueba de Esfuerzo/métodos , Isquemia Miocárdica/diagnóstico por imagen , Isquemia Miocárdica/fisiopatología , Agonistas Adrenérgicos beta , Adulto , Anciano , Anciano de 80 o más Años , Análisis de Varianza , Antiarrítmicos , Atropina , Diástole , Dobutamina , Femenino , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Prospectivos , Proyectos de Investigación , Sístole
18.
J Am Coll Cardiol ; 38(3): 690-7, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11527619

RESUMEN

OBJECTIVES: This study examined gender differences and temporal changes in the clinical characteristics of patients referred for nuclear stress imaging, their imaging results and subsequent utilization of coronary angiography and revascularization. BACKGROUND: Gender bias may influence resource utilization in patients with coronary artery disease (CAD). No study has analyzed gender differences and time trends in patients referred for noninvasive testing and subsequent use of invasive procedures. METHODS: Between January 1986 and December 1995, 14,499 patients (5,910 women and 8,589 men) without established CAD underwent stress myocardial perfusion imaging. The clinical characteristics, imaging results, coronary angiograms and revascularization outcomes were compared in women and men over time. RESULTS: The mean pretest probability of CAD was lower in women (45%) than in men (70%) (p < 0.001). More women (69%) than men (42%) had normal nuclear images (p < 0.001). Men (17%) were more likely than women (8%) to undergo coronary angiography (p < 0.001). Male gender was independently associated with referral for coronary angiography (multivariate model: chi-square = 16, p < 0.001) but was considerably weaker than the imaging variables (summed reversibility score: chi-square = 273, p < 0.001). Revascularization was performed in more men (46% of the population undergoing angiography) than women (39%) (p = 0.01), but gender was not independently associated with referral to revascularization. There were no significant differences in clinical, imaging or invasive variables between the genders over time. CONCLUSIONS: There was little evidence for a bias against women in this study. Women were somewhat less likely to undergo coronary angiography but were referred for stress perfusion imaging more liberally. Practice patterns remained constant over this 10-year period.


Asunto(s)
Sesgo , Enfermedad Coronaria/diagnóstico por imagen , Enfermedad Coronaria/epidemiología , Tomografía Computarizada de Emisión de Fotón Único/estadística & datos numéricos , Angioplastia Coronaria con Balón , Angiografía Coronaria , Puente de Arteria Coronaria , Enfermedad Coronaria/terapia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores Sexuales , Radioisótopos de Talio
19.
J Am Coll Cardiol ; 38(3): 867-75, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11527647

RESUMEN

OBJECTIVES: We sought to assess the impact of contrast injection and harmonic imaging, on the measure by echocardiography of left ventricular (LV) remodeling. BACKGROUND: Left ventricular remodeling is a precursor of LV dysfunction, but the impact of contrast injection and harmonic imaging on the accuracy or reproducibility of echocardiography is unclear. METHODS: We prospectively collected LV images by using simultaneous methods. Then, LV volumes were measured off-line, in blinded manner and in random order. The accuracy of echocardiography was determined in comparison to electron beam computed tomography (EBCT) in 26 patients. The reproducibility of echocardiography was assessed by three blinded observers with different training levels in 32 patients. RESULTS: End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF), as measured by EBCT (195 +/- 55, 58 +/- 24 and 137 +/- 35 ml and 71 +/- 5%, respectively) and echocardiography with harmonic imaging and contrast injection (194 +/- 51, 55 +/- 20 and 140 +/- 35 ml and 72 +/- 4%, respectively), showed no differences (all p > 0.15) and excellent correlations (all r > 0.87). In contrast, echocardiography using harmonic imaging without contrast injection underestimated the EBCT results (all p < 0.01). Reproducibility was superior with rather than without contrast injection for intraobserver and interobserver variabilities (all p < 0.001). Values measured by different observers were different without contrast injection, but were similar with contrast injection (all p > 0.18). Consequently, intrinsic patient differences represented a larger and almost exclusive proportion of global variability with contrast injection for EDV (94 vs. 79%), ESV (93 vs. 82%), SV (87 vs. 53%) and EF (84 vs. 41%), as compared with harmonic imaging without contrast injection (all p < 0.005). CONCLUSIONS: For assessment of LV remodeling, echocardiography with harmonic imaging and contrast injection improved the accuracy and reproducibility, as compared with imaging without contrast injection. With contrast injection, variability was almost exclusively due to intrinsic patient differences. Therefore, when evaluation of LV remodeling is deemed important, assessment after contrast injection should be the preferred echocardiographic approach.


Asunto(s)
Ecocardiografía Doppler/métodos , Aumento de la Imagen , Función Ventricular Izquierda , Remodelación Ventricular , Anciano , Albúminas , Medios de Contraste , Femenino , Fluorocarburos , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Estudios Prospectivos , Reproducibilidad de los Resultados , Volumen Sistólico , Tomografía Computarizada por Rayos X/métodos
20.
Am J Med ; 111(2): 96-102, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11498061

RESUMEN

PURPOSE: We sought to determine the importance of a third heart sound (S(3)) and its relation to hemodynamic and valvular dysfunction. SUBJECTS AND METHODS: We prospectively enrolled 580 patients who had isolated valvular regurgitation (mitral, n = 299; aortic, n = 121) or primary left ventricular dysfunction with or without functional mitral regurgitation (n = 160). We analyzed the associations between the clinical finding of an audible S(3) (as noted in routine clinical practice by internal medicine physicians) and hemodynamic alterations measured by comprehensive quantitative Doppler echocardiography. RESULTS: S(3) was more prevalent in patients with primary left ventricular dysfunction (46%, n = 73) than in organic mitral (16%, n = 47) or aortic (12%, n = 14) regurgitation (P <0.001). Patients with an S(3) were more likely to have class III-IV symptoms (55% [74 of 137] vs. 18% [80 of 443] of those without an S(3), P <0.001) and had a higher mean [+/- SD] pulmonary pressure (55 +/- 15 vs. 41 +/- 11 mm Hg, P <0.001). An S(3) was also related to a higher early filling velocity due to a greater filling volume, restrictive filling, or both. An S(3) was a marker of severe regurgitation (regurgitant fraction > or =40%) in patients with primary left ventricular dysfunction (odds ratio [OR] = 2.4; 95% confidence interval [CI]: 1.1 to 5.5), mitral regurgitation (OR = 17; 95% CI: 5.8 to 52), and aortic regurgitation (OR = 7.1; 95% CI: 1.8-28). An S(3) was also associated with restrictive filling in primary left ventricular dysfunction (OR = 3.0; 95% CI, 1.6 to 5.9), marked dilatation in mitral regurgitation (OR = 20; 95% CI: 6.8 to 58), and an ejection fraction (<50%) in aortic regurgitation (OR = 19; 95% CI: 6.0 to 62). CONCLUSION: An audible S(3) is an important clinical finding, indicating severe hemodynamic alterations, and should lead to a comprehensive assessment and consideration of vigorous medical or surgical treatment.


Asunto(s)
Insuficiencia de la Válvula Aórtica/fisiopatología , Ecocardiografía Doppler , Soplos Cardíacos/fisiopatología , Insuficiencia de la Válvula Mitral/fisiopatología , Disfunción Ventricular Izquierda/fisiopatología , Anciano , Insuficiencia de la Válvula Aórtica/diagnóstico por imagen , Velocidad del Flujo Sanguíneo , Presión Sanguínea , Diagnóstico Diferencial , Diástole , Femenino , Soplos Cardíacos/diagnóstico por imagen , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Insuficiencia de la Válvula Mitral/diagnóstico por imagen , Variaciones Dependientes del Observador , Valor Predictivo de las Pruebas , Estudios Prospectivos , Presión Esfenoidal Pulmonar , Volumen Sistólico , Sístole , Disfunción Ventricular Izquierda/diagnóstico por imagen
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