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1.
J Community Health Nurs ; 40(4): 266-272, 2023 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-37310163

RESUMEN

PURPOSE: This study evaluated the effectiveness of a community-based, interdisciplinary, medication education intervention for rural older adults. METHODS: The research design was a quasi-experimental pretest/posttest design. Self-efficacy, adherence to refills and medication, and knowledge were examined. An educational intervention was conducted with each participant on their prescribed medications. FINDINGS: Mean scores for the adherence to refills and medication subscale decreased from 9.9 to 8.5 (p = .003) indicating improved adherence. Mean scores for the knowledge subscale increased from 21.8 to 22.4 (p = .192). CONCLUSIONS: Results suggest a community-based, interdisciplinary, individualized medication education intervention could increase medication adherence in rural older adults.


Asunto(s)
Educación en Salud , Cumplimiento de la Medicación , Humanos , Anciano , Escolaridad , Población Rural
2.
J Gerontol Nurs ; 47(4): 7-12, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34038247

RESUMEN

This process evaluation of the Rural Elder Awareness of Medication Safety (REAMS) program provided identification of successful and unsuccessful elements along with barriers to and facilitators of this home-based pilot program. The REAMS program was developed to assist rural older adults aged >65 years and community health care organizations with strategies to improve health literacy related to medications. Recruitment of older adults, rurality of the program's setting, time constraints, and the onset of the COVID-19 pandemic were the greatest barriers. The collaborative relationship developed with community health care partners was the greatest facilitator. This relationship promoted shared ideas and adjustments in program design to achieve the outcome goals. The lessons learned from process evaluation may benefit future researchers or community health promotion planners with designing community-based programs for older adults in rural areas. Future research should focus on expanding recruitment opportunities in acute care, primary care, and home health with the inclusion of all established health care providers in the community. [Journal of Gerontological Nursing, 47(4), 7-12.].


Asunto(s)
Anciano Frágil , Alfabetización en Salud , Servicios de Atención de Salud a Domicilio/organización & administración , Educación del Paciente como Asunto/métodos , Conocimiento de la Medicación por el Paciente , Seguridad del Paciente , Servicios de Salud Rural/organización & administración , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Proyectos Piloto , Población Rural , Estados Unidos
3.
Nurs Educ Perspect ; 38(4): 198-200, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28628069

RESUMEN

Prolonged sitting time (ST) is a distinct risk factor for early mortality and cardiovascular disease. The purpose of this descriptive correlational study was to examine ST and health of Kentucky nurse educators. The written survey included demographic items, general health items, and ST. Total average ST was 10.8 hours (workdays) and 8 hours (non-workdays). There was no relationship between body mass index and ST; however, the medication used to treat hypertension and hypercholesterolemia was associated with increased ST. Nurse educators are at risk for negative health effects of prolonged ST, and effective interventions are imperative.


Asunto(s)
Docentes de Enfermería , Conducta Sedentaria , Humanos , Factores de Riesgo , Encuestas y Cuestionarios
4.
J Contin Educ Nurs ; 52(10): 482-488, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34609251

RESUMEN

BACKGROUND: An asynchronous online continuing education (CE) program was created to increase nurses' awareness and knowledge of occupationally related mental health issues among farmers. METHOD: The ADDIE (analysis, design, development, implementation, evaluation) model was followed to create the CE program. Articulate Storyline 3 (Articulate 360), a software tool, was used to build an interactive, e-learning, and virtual training module. RESULTS: The course was completed by 113 nurses. Eighty-two (72.5%) of these nurses completed the course evaluation. Of these, 69 (84.1%) reported that the course met their expectations. The majority of respondents indicated that the material was presented in a clear, organized manner (80.0%, n = 80) and that all course objectives were met, including being able to identify sources of stress among farmers (86.3%, n = 80), recognize manifestations of stress among farmers (86.4%, n = 81), understand farmers' mental health status (86.3%, n = 80), and identify mental health nursing practices (87.3%, n = 79). CONCLUSION: Nurses can provide more salient care to the farming population when they are equipped with an understanding of the culture and stress associated with farming. This online educational program has the potential to improve mental health care for farmers and their families. [J Contin Educ Nurs. 2021;52(10):482-488.].


Asunto(s)
Educación a Distancia , Enfermeras y Enfermeros , Educación Continua en Enfermería , Agricultores , Humanos , Salud Mental
5.
Eur J Paediatr Neurol ; 11(3): 160-6, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17257866

RESUMEN

OBJECTIVE: Scoliosis is a frequent complication (68-90%) of Duchenne muscular dystrophy (DMD). Prevention of limb deformities, rehabilitation in knee-ankle-foot-orthoses (KAFOs) and glucocorticoids prolong walking and standing, and might reduce scoliosis. We evaluated possible predictive factors for scoliosis development in a large DMD population. METHODS: Case notes of 123 DMD boys, > or = 17 years, followed at our centre between 1992 and 2002 were reviewed. Univariate analysis was used to relate two outcome measures (age at onset of scoliosis and severity at 17 years) with (i) glucocorticoids treatment; (ii) ages at (a) loss of independent ambulation, (b) rehabilitation into KAFOs, (c) loss of standing, (iii) forced vital capacity (FVC) (%) between 11 and 12 years and (iv) lower limb contractures. RESULTS: In total, 37/123 boys (30%) received intermittent prednisolone (0.75 mg/kg/day, 10 day/month) for a median 1-year (2 months-9 years), starting between 7.7 and 12.4 years (mean 9.5). About 96/123 (78%) were rehabilitated into KAFOs at 10.2+/-1.6 years. Age at loss of ambulation in KAFOs was 12.3+/-1.9 years and at loss of standing 12.8+/-2.1 years. About 95/123 (77%) boys developed scoliosis (Cobb angle >30 degrees ). Mean age+/-S.D. at scoliosis onset was 12.7+/-1.6 years. Forty-three boys (35%) had scoliosis surgery by 15+/-1.2 years. Later age at loss of ambulation (p<0.0001) and longer duration of prednisolone treatment (p=0.01) related to later scoliosis onset. Ages at loss of ambulation and standing were inversely related to scoliosis severity at 17 years (p<0.005). Hip asymmetry and %FVC at 11-12 years were directly related to scoliosis severity (p=0.02). CONCLUSIONS: Our data indicate a significant association between prolonged ambulation and a reduced risk of scoliosis development. Glucocorticoid administration, in our series, appear to be associated with a later onset of scoliosis, but did not alter the severity at 17 years, probably reflecting the shorter overall glucocorticoid exposure in this population.


Asunto(s)
Distrofia Muscular de Duchenne/complicaciones , Escoliosis/etiología , Adolescente , Factores de Edad , Edad de Inicio , Progresión de la Enfermedad , Humanos , Modelos Logísticos , Masculino , Distrofia Muscular de Duchenne/terapia , Valor Predictivo de las Pruebas , Prednisolona/uso terapéutico , Estudios Retrospectivos , Factores de Riesgo , Escoliosis/prevención & control
6.
Dalton Trans ; 46(45): 15704-15709, 2017 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-29094739

RESUMEN

A novel, facile and efficient method was developed for the activation of acetic acid modulated zirconium MOFs. The protocol involves briefly heating the material in water using microwave irradiation. MOF-808, DUT-84 and UiO-66 were all activated in this manner to remove the modulator and organic solvent from the framework post synthesis, with retention of MOF integrity post activation. The degree of activation was characterised by the use of TGA and NMR. The catalytic activity of the activated MOFs and their non-activated counterparts was investigated for chemical warfare agent (CWA) hydrolysis. Upon activation, an increase in the rate of hydrolysis was observed in the degradation of CWA simulant dimethyl 4-nitrophenyl phosphate (DMNP). MOF-808 and DUT-84 were also screened as catalysts for the hydrolysis of the V-series agent VM, with remarkable half-lives obtained for MOF-808 in the absence of any buffers. Currently employed MOF activation procedures involve the use of additional organic solvents post synthesis; we believe this method to be ideally efficacious for the organic desolvation of zirconium MOFs and removing modulator additives.

7.
Neuromuscul Disord ; 16(2): 93-8, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16427782

RESUMEN

The aim of this study was to validate the Hammersmith functional motor scale for children with spinal muscular atrophy in a large cohort of 90 non-ambulant children with spinal muscular atrophy type 2 or 3. All had a baseline assessment (T0) and were reassessed either at 3 months (T1) (n = 66) or at 6 months (T2) (n = 24). Inter-observer reliability, tested on 13 children among 3 examiners, was > 95%. Of the 66 children examined after 3 months 4 had adverse effects in between assessments and were excluded from the analysis. Forty-two (68%) of the remaining 62 reassessed had no variation in scores between T0 and T1 and 13 (21%) were within +/- 1 point. 9 (37.5%) of the 24 children reassessed after 6 months had no variation in scores between T0 and T2 and another 9 (37.5%) had variations within +/- 1 point. Our study confirms previous observations of the reliability of the scale and helps to establish a baseline for assessing changes of functional ability over 3 and 6 month intervals. This information can be valuable in view of therapeutic trials.


Asunto(s)
Neuronas Motoras/fisiología , Desempeño Psicomotor , Atrofias Musculares Espinales de la Infancia/fisiopatología , Niño , Preescolar , Estudios de Cohortes , Interpretación Estadística de Datos , Femenino , Humanos , Italia , Masculino , Variaciones Dependientes del Observador , Estudios Prospectivos , Análisis de Regresión , Reproducibilidad de los Resultados , Factores de Tiempo , Reino Unido
8.
Biochim Biophys Acta ; 1336(3): 434-44, 1997 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-9367171

RESUMEN

The ligand 1,4,7-triazacyclononane-1,4,7-tris(methylene methylphosphinic acid), NOTMP, was used to measure free MgII levels in blood plasma by 31P MRS. Separate resonances were observed for the free ligand and the MgII complex and the ratio of their resonance areas was used to evaluate the free, ionized MgII concentration, [Mg]free. The CaII and the ZnII complexes gave rise to separate resonances in the 31P spectrum in an aqueous sample. In human blood plasma samples, however, these resonances were never observed thus excluding the interference of these metal ions. Heparin, up to 150 units/ml, had no influence on the Mg-NOTMP equilibrium. The 31P MRS methodology was applied to twenty human blood plasma samples. Total MgII ([Mg]total), as measured by atomic absorption spectroscopy, averaged 0.85 +/- 0.12 mM while free ionized MgII ([Mg]free) measured by 31P MRS was 0.66 +/- 0.09 mM. The 31P MRS method gave inherently larger values for free ionized MgII than that reported by ion-selective electrodes (ISE). This was traced to a redistribution of existing plasma MgII species after the addition of about 2 mM of NOTMP. Calculations using existing thermodynamic data show that the ionized MgII concentration (iMg) and the concentration of MgII weakly complexed to small anions (Mg(comp)) both drop after the addition of NOTMP, with Mg(comp) dropping to negligible levels. Thus, the 31P MRS method appears to be less sensitive to variations in the concentration of weakly binding anions (bicarbonate, carbonate, chloride, lactate, phosphate, etc.) than the ISE method. Our data indicates that the difference between Mg(total), as measured by atomic absorption spectroscopy, and Mg(free), as measured by 31P MRS, provides an direct estimate of the protein bound MgII fraction.


Asunto(s)
Magnesio/sangre , Aniones , Calcio/sangre , Heparina , Humanos , Concentración de Iones de Hidrógeno , Indicadores y Reactivos , Ligandos , Espectroscopía de Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Modelos Químicos , Compuestos Organofosforados , Fósforo , Reproducibilidad de los Resultados , Espectrofotometría Atómica
9.
J Am Coll Cardiol ; 28(2): 455-9, 1996 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8800125

RESUMEN

OBJECTIVES: We studied the accuracy of dobutamine echocardiography for the detection of myocardial viability in patients with an occluded left anterior descending coronary artery and regional ventricular dysfunction. BACKGROUND: Contractile reserve during dobutamine echocardiography is an accurate marker of myocardial viability in patients with coronary stenoses and ventricular dysfunction. However, its accuracy in patients with an occluded vessel has not been evaluated. METHODS: We studied 41 patients with > 50% stenosis of the left anterior descending coronary artery and regional ventricular dysfunction who underwent dobutamine echocardiography for detection of viable myocardium. Contractile reserve was defined as improvement in wall motion score of two or more contiguous septal or anterior segments during doubutamine echocardiography. Recovery of function was defined as improvement in rest wall motion score of two or more contiguous segments after revascularization. RESULTS: Patients were classified into two groups according to the presence (n = 20) or absence (n = 21) of left anterior descending coronary artery occlusion. Contractile reserve was detected in 40% of patients with an occluded and 43% with a nonoccluded artery (p = 0.8). Of 41 patients, 27 underwent revascularization, 12 with and 15 without an occluded vessel. Recovery of function occurred in 6 (50%) of 12 patients in the occluded artery group and in 5 (33%) of 15 in the nonoccluded artery group (p = 0.4). Among patients with an occluded artery, the positive and negative predictive values of dobutamine echocardiography for recovery of function were 100% (95% confidence interval [CI] 48% to 100%) and 86% (95% CI 42% to 100%), respectively. CONCLUSIONS: Our results indicate that contractile reserve during dobutamine echocardiography can be detected in patients with an occluded vessel and may be useful for predicting recovery of function after revascularization.


Asunto(s)
Enfermedad Coronaria/diagnóstico por imagen , Dobutamina , Ecocardiografía , Disfunción Ventricular Izquierda/diagnóstico por imagen , Estudios de Casos y Controles , Angiografía Coronaria , Enfermedad Coronaria/complicaciones , Enfermedad Coronaria/cirugía , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Contracción Miocárdica/fisiología , Revascularización Miocárdica , Valor Predictivo de las Pruebas , Factores de Tiempo , Disfunción Ventricular Izquierda/etiología
10.
J Am Coll Cardiol ; 38(5): 1390-4, 2001 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-11691513

RESUMEN

OBJECTIVES: The goal of this study was to determine, in patients with a recent myocardial infarction (MI) and residual wall motion abnormalities within the distribution of the infarct-related artery, whether normal perfusion by myocardial contrast echocardiography (MCE) would accurately predict recovery of segmental left ventricular (LV) function. BACKGROUND: Left ventricular dysfunction after acute MI may be secondary to myocardial stunning or necrosis. Recent technical innovations in contrast echocardiography, including pulse inversion imaging and power Doppler, now allow full-motion echocardiographic perfusion assessment from a venous injection of fluorocarbon-based contrast agent. METHODS: Thirty-four patients with recent MI underwent baseline wall motion assessment and MCE two days after admission and follow-up echocardiography a mean of 55 days later. RESULTS: Perfusion by MCE predicted recovery of segmental function with a sensitivity of 77%, specificity of 83%, positive predictive value of 90% and overall accuracy of 79%. The mean wall motion score at follow-up was significantly better in perfused, compared with nonperfused, segments (1.4 vs. 2.2, p < 0.0001). Additionally, 90% of perfused segments improved, while the majority of nonperfused segments remained unchanged. CONCLUSIONS: Full-motion MCE utilizing an intravenous fluorocarbon-based agent and pulse inversion power Doppler techniques, identifies stunned myocardium, and accurately predicts recovery of segmental LV function in patients with recent MI.


Asunto(s)
Ecocardiografía Doppler/métodos , Ecocardiografía Doppler/normas , Infarto del Miocardio/complicaciones , Aturdimiento Miocárdico/diagnóstico por imagen , Aturdimiento Miocárdico/etiología , Disfunción Ventricular Izquierda/diagnóstico por imagen , Disfunción Ventricular Izquierda/etiología , Anciano , Albúminas , Angioplastia Coronaria con Balón , Angiografía Coronaria , Diagnóstico Diferencial , Ecocardiografía Doppler/instrumentación , Femenino , Fibrinolíticos/uso terapéutico , Fluorocarburos , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/patología , Infarto del Miocardio/terapia , Aturdimiento Miocárdico/patología , Necrosis , Valor Predictivo de las Pruebas , Pronóstico , Estudios Prospectivos , Recuperación de la Función , Método Simple Ciego , Resultado del Tratamiento , Ácidos Triyodobenzoicos , Disfunción Ventricular Izquierda/patología
11.
J Am Coll Cardiol ; 35(1): 201-8, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10636281

RESUMEN

OBJECTIVES: To determine the effect of preload in color M-mode Doppler flow propagation velocity (v(p)). BACKGROUND: The interpretation of Doppler filling patterns is limited by confounding effects of left ventricular (LV) relaxation and preload. Color M-mode v(p) has been proposed as a new index of LV relaxation. METHODS: We studied four dogs before and during inferior caval (IVC) occlusion at five different inotropic stages and 14 patients before and during partial cardiopulmonary bypass. Left ventricular (LV) end-diastolic volumes (LV-EDV), the time constant of isovolumic relaxation (tau), left atrial (LA) pre-A and LV end-diastolic pressures (LV-EDP) were measured. Peak velocity during early filling (E) and v(p) were extracted by digital analysis of color M-mode Doppler images. RESULTS: In both animals and humans, LV-EDV and LV-EDP decreased significantly from baseline to IVC occlusion (both p < 0.001). Peak early filling (E) velocity decreased in animals from 56 +/- 21 to 42 +/- 17 cm/s (p < 0.001) without change in v(p) (from 35 +/- 15 to 35 +/- 16, p = 0.99). Results were similar in humans (from 69 +/- 15 to 53 +/- 22 cm/s, p < 0.001, and 37 +/- 12 to 34 +/- 16, p = 0.30). In both species, there was a strong correlation between LV relaxation (tau) and v(p) (r = 0.78, p < 0.001, r = 0.86, p < 0.001). CONCLUSIONS: Our results indicate that color M-mode Doppler v(p) is not affected by preload alterations and confirms that LV relaxation is its main physiologic determinant in both animals during varying lusitropic conditions and in humans with heart disease.


Asunto(s)
Volumen Sanguíneo/fisiología , Ecocardiografía Doppler en Color , Contracción Miocárdica/fisiología , Función Ventricular Izquierda/fisiología , Anciano , Animales , Velocidad del Flujo Sanguíneo/fisiología , Presión Sanguínea/fisiología , Enfermedad Coronaria/diagnóstico por imagen , Enfermedad Coronaria/fisiopatología , Enfermedad Coronaria/cirugía , Diástole/fisiología , Perros , Femenino , Enfermedades de las Válvulas Cardíacas/diagnóstico por imagen , Enfermedades de las Válvulas Cardíacas/fisiopatología , Enfermedades de las Válvulas Cardíacas/cirugía , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Valores de Referencia
12.
Cardiovasc Res ; 19(11): 674-8, 1985 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-4075357

RESUMEN

The action potential duration (APD) was measured using an Ag-AgCl electrode, in open chest anaesthetised dogs (n = 8) and puppies, 4 to 6 months old (n = 8), with complete atrio-ventricular dissociation and beta-adrenergic blockade. They were paced in the control period at a frequency of 120 beats . min-1. Both adults and puppies showed maximum action potential duration at a test pulse interval of over 700 ms. Below this the adult dogs showed a progressive shortening of the action potential duration (mean APD 81.5% at 200 ms). In contrast, the puppies showed much less shortening (91% at 200 ms; p less than 0.001). Measurements of Na+, K+-ATPase activity by the Rb uptake method gave values of 13.4 +/- 1.3 (puppies, n = 4) and 6.1 +/- 1.1 (adults, n = 6). These results may be consistent with the idea of a greater influx and efflux of sodium in the myocardial cells of the puppy compared with the adult dog.


Asunto(s)
Envejecimiento , Corazón/fisiología , Potenciales de Acción , Animales , Perros , Factores de Tiempo
13.
FEBS Lett ; 441(1): 6-10, 1998 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-9877154

RESUMEN

Swiss 3T3 cell lines were constructed co-expressing receptor activity modifying protein (RAMP) 1 with the calcitonin receptor-like receptor (CRLR), and showed 125I-calcitonin-gene-related peptide (CGRP) 1 binding indicative of a type I CGRP receptor. Application of CGRP1 led to an increase in cAMP, which in 2/5 cell lines was augmented following pertussis toxin (PTX) pre-treatment. In Xenopus oocytes, expression of RAMP1, which potentiates an endogenous CGRP receptor, led to constitutive activation of co-expressed GIRK potassium channels. This potassium current was increased following CGRP application or co-expression of CRLR, but decreased by PTX or co-expression of transducin. We conclude that the CGRP receptor can signal to both PTX sensitive and insensitive G proteins.


Asunto(s)
Proteínas de Unión al GTP/metabolismo , Proteínas de la Membrana/metabolismo , Canales de Potasio de Rectificación Interna , Receptores de Péptido Relacionado con el Gen de Calcitonina/fisiología , Receptores de Calcitonina/fisiología , Células 3T3 , Animales , Péptido Relacionado con Gen de Calcitonina/metabolismo , Péptido Relacionado con Gen de Calcitonina/farmacología , Proteína Similar al Receptor de Calcitonina , Línea Celular , AMP Cíclico/metabolismo , Canales de Potasio Rectificados Internamente Asociados a la Proteína G , Humanos , Péptidos y Proteínas de Señalización Intracelular , Proteínas de la Membrana/genética , Ratones , Oocitos/fisiología , Toxina del Pertussis , Canales de Potasio/metabolismo , Proteína 1 Modificadora de la Actividad de Receptores , Proteínas Modificadoras de la Actividad de Receptores , Receptores de Calcitonina/genética , Receptores de Péptido Relacionado con el Gen de Calcitonina/genética , Proteínas Recombinantes/metabolismo , Transducina/genética , Transducina/fisiología , Transfección , Factores de Virulencia de Bordetella/farmacología , Xenopus
14.
Neurology ; 59(4): 609-10, 2002 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-12196659

RESUMEN

The aim of this pilot study was to evaluate the effect of albuterol in children with spinal muscular atrophy (SMA). Thirteen patients (five with SMA II and eight with SMA III) were given oral albuterol for 6 months. There was a significant increase in myometry, forced vital capacity, and lean body mass between the baseline and the 6-month assessments (p < 0.05). Albuterol may have a beneficial effect in patients with SMA without causing any significant adverse effects. Larger randomized, placebo-controlled trials are needed to confirm this observation.


Asunto(s)
Agonistas Adrenérgicos beta/uso terapéutico , Albuterol/uso terapéutico , Atrofias Musculares Espinales de la Infancia/tratamiento farmacológico , Absorciometría de Fotón , Agonistas Adrenérgicos beta/efectos adversos , Albuterol/efectos adversos , Presión Sanguínea/efectos de los fármacos , Composición Corporal/efectos de los fármacos , Niño , Preescolar , Estudios de Cohortes , Esquema de Medicación , Electrocardiografía/efectos de los fármacos , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Contracción Isométrica/efectos de los fármacos , Masculino , Contracción Muscular/efectos de los fármacos , Proyectos Piloto , Resultado del Tratamiento , Capacidad Vital/efectos de los fármacos
15.
Neuropharmacology ; 38(11): 1647-56, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10587080

RESUMEN

The GABA(B) receptor has been shown to consist of a heterodimer of two related 7-transmembrane receptors GABAB-R1 and GABA(B)-R2. These receptors share close homology to the Ca2+-sensing receptor and also to the metabotropic glutamate receptors, which have also been shown to respond to extracellular calcium. We show here that the GABA(B) receptor also has Ca2+ sensing properties. Ca2+ (0.001-1 mM) potentiated the GABA stimulation of [35S]GTPgammaS binding in membranes prepared from CHO cells stably expressing the GABA(B)-R1/R2 heterodimer. The GABA EC50 was reduced from 72 to 7.7 microM by addition of 1 mM Ca2+, with no change in the maximum response. A similar effect was observed in membranes from rat brain cortex. Ca2+ also potentiated GABA inhibition of forskolin-stimulated cAMP levels in the CHO cells and enhanced coupling to GIRK K+ channels in Xenopus oocytes. Other divalent cations were ineffective. The effects of Ca2+ were found to be agonist dependent with baclofen having a reduced sensitivity compared to GABA. Calcium appears to act allosterically to enhance GABA responses at the GABA(B) receptor, however, unlike the Ca2+-sensing receptor and some of the mGluR family, Ca2+ does not act as a ligand in its own right.


Asunto(s)
Calcio/farmacología , Corteza Cerebral/efectos de los fármacos , Guanosina 5'-O-(3-Tiotrifosfato)/metabolismo , Receptores de GABA-B/efectos de los fármacos , Receptores de Glutamato Metabotrópico/efectos de los fármacos , Ácido gamma-Aminobutírico/farmacología , Secuencia de Aminoácidos/genética , Animales , Baclofeno/farmacología , Células CHO , Calcio/fisiología , Corteza Cerebral/metabolismo , Cricetinae , Agonistas del GABA/farmacología , Masculino , Ratas , Receptores de GABA-B/genética , Receptores de GABA-B/metabolismo , Receptores de Glutamato Metabotrópico/genética , Receptores de Glutamato Metabotrópico/metabolismo , Xenopus , Ácido gamma-Aminobutírico/fisiología
16.
Am J Cardiol ; 79(10): 1309-13, 1997 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-9165148

RESUMEN

Contractile reserve, during low-dose dobutamine echocardiography, is frequently used for the assessment of myocardial viability in patients with coronary artery disease (CAD) and left ventricular (LV) dysfunction. Whether contractile reserve is affected by the severity of the underlying CAD is presently unknown. Accordingly, we studied 58 patients with stable CAD and LV dysfunction who underwent coronary angiography and low-dose dobutamine echocardiography. In each vascular region the worst stenosis was identified and quantitated as percent diameter stenosis. Segmental wall motion during echocardiography was scored visually and rest and dobutamine wall motion score indexes were calculated. Contractile reserve was defined as > or = 1 grade improvement in wall motion score of > or = 2 contiguous segments along with > or = 20% reduction in global wall motion score index with dobutamine. There was no difference between patients with (n = 26) and without (n = 32) contractile reserve in percent coronary stenosis (89 +/- 17% vs 87 +/- 17%, p = 0.6), number of coronary arteries with > 50% diameter stenosis (2.0 +/- 0.8 vs 2.2 +/- 0.7, p = 0.4), number of occluded coronary arteries (1.2 +/- 0.9 vs 1.1 +/- 0.9, p = 0.6), or the prevalence of collaterals demonstrated angiographically (61% vs 56%, p = 0.5). Our data demonstrates that in patients with CAD and LV dysfunction, the prevalence of contractile reserve during low-dose dobutamine echocardiography is independent of the angiographic extent and severity of CAD.


Asunto(s)
Cardiotónicos , Enfermedad Coronaria/diagnóstico por imagen , Enfermedad Coronaria/fisiopatología , Dobutamina , Ecocardiografía , Contracción Miocárdica , Disfunción Ventricular Izquierda/fisiopatología , Cardiotónicos/administración & dosificación , Angiografía Coronaria , Dobutamina/administración & dosificación , Humanos , Persona de Mediana Edad , Estudios Prospectivos , Estudios Retrospectivos , Disfunción Ventricular Izquierda/diagnóstico por imagen
17.
Am J Cardiol ; 82(5): 564-8, 1998 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-9732880

RESUMEN

Dobutamine atropine stress echocardiography (DASE) detects coronary artery disease (CAD) by increasing myocardial oxygen demand causing ischemia. The sensitivity of the test for detection of CAD is reduced in patients with submaximal stress. We hypothesized that increasing cardiac work load by adding isometric exercise would improve the detection of ischemia during DASE. We studied 31 patients, mean age 57+/-11 years, with angiographically documented CAD. Patients underwent DASE using incremental dobutamine doses from 5 to 40 microg/kg/min, followed by atropine if peak heart rate was <85% of predicted maximal. Hand grip was then performed for 2 minutes at 33% of maximal voluntary contraction, while dobutamine infusion was maintained at the peak dose. The addition of hand grip during dobutamine stress was associated with a significant increase in systolic blood pressure (143+/-21 vs 164+/-24 mm Hg, p = 0.001) and left ventricular end-systolic circumferential wall stress (72+/-30 x 10(3) dynes/cm2 vs 132+/-34 x 10(3) dynes/cm2, p = 0.004). Wall motion score index increased from 1.0 at rest to 1.15+/-0.18 with dobutamine (p = 0.0004 vs rest), and increased further to 1.29+/-0.22 with the addition of hand grip (p = 0.004 vs dobutamine). Ischemia was detected in 19 patients (62%) with dobutamine-atropine stress alone and in 25 (83%) after the addition of hand grip (p <0.05). The addition of hand grip during DASE is feasible, and improves the detection of myocardial ischemia.


Asunto(s)
Angina de Pecho/diagnóstico por imagen , Atropina , Cardiotónicos , Enfermedad Coronaria/diagnóstico por imagen , Dobutamina , Ecocardiografía , Prueba de Esfuerzo , Fuerza de la Mano/fisiología , Contracción Isométrica/fisiología , Adulto , Anciano , Angina de Pecho/fisiopatología , Circulación Coronaria/efectos de los fármacos , Circulación Coronaria/fisiología , Enfermedad Coronaria/fisiopatología , Ecocardiografía/efectos de los fármacos , Prueba de Esfuerzo/efectos de los fármacos , Femenino , Hemodinámica/efectos de los fármacos , Hemodinámica/fisiología , Humanos , Masculino , Persona de Mediana Edad , Miocardio/metabolismo , Consumo de Oxígeno/efectos de los fármacos , Consumo de Oxígeno/fisiología
18.
Am J Cardiol ; 83(2): 218-22, 1999 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-10073824

RESUMEN

Endocardial resolution during 2-dimensional echocardiography is technically limited in at least 10% to 15% of patients. Recently, several ultrasound imaging innovations have been introduced that may improve endocardial resolution and decrease the proportion of technically difficult studies. This study compares tissue harmonic imaging, intravenous sonicated albumin, and Doppler myocardial imaging in patients with technically difficult echocardiograms. Twenty-eight patients with known or suspected cardiac disease and poor baseline endocardial resolution were studied. Only harmonic imaging (conventional and optimized for tissue) was superior to baseline fundamental imaging (p <0.001). Harmonic imaging was superior to baseline imaging in all myocardial regions and in the majority of patients, including those with the worst baseline studies.


Asunto(s)
Albúminas , Medios de Contraste , Ecocardiografía Doppler/métodos , Endocardio/diagnóstico por imagen , Anciano , Ecocardiografía/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos
19.
Br J Pharmacol ; 111(2): 483-8, 1994 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8004393

RESUMEN

1. High voltage-activated calcium currents were recorded in nerve growth factor (NGF)-differentiated PC12 cells with the whole-cell patch clamp technique. After exposure to NGF for 3-10 days the PC12 cells developed neurone-like processes and calcium currents which were pharmacologically separable into L- and N-types (defined by sensitivity to nifedipine and omega-conotoxin GVIA respectively). 2. After blocking the L-type calcium channels with nifedipine (10 microM), omega-conotoxin GVIA blocked approximately 85% of the remaining calcium current with an IC50 of 3 nM and a Hill coefficient of 1. The block by conotoxin GVIA was irreversible on the time scale of these experiments. These results suggested that the majority of the nifedipine-insensitive calcium current was N-type. 3. Fluspirilene, a substituted diphenylbutylpiperidine with potent neuroleptic properties, reversibly inhibited the N-type component in a dose-dependent manner with an IC50 of 30 nM. The Hill coefficient of the block was 0.25. The fraction of current blocked was the same at all test potentials examined (-30 to +40 mV). 4. These data indicate that the neuroleptic properties of fluspirilene may be due, at least in part, to an inhibition of neuronal N-type calcium channels. This finding raises the possibility that modulation of N-type calcium channel activity by drugs derived from substituted diphenylbutylpiperidines may provide a novel way of altering neurotransmitter release and hence brain function.


Asunto(s)
Bloqueadores de los Canales de Calcio/farmacología , Fluspirileno/farmacología , Factores de Crecimiento Nervioso/farmacología , Animales , Cadmio/farmacología , Canales de Calcio/efectos de los fármacos , Canales de Calcio/metabolismo , Diferenciación Celular/efectos de los fármacos , Medios de Cultivo , Electrofisiología , Cinética , Nifedipino/farmacología , Células PC12 , Péptidos/farmacología , omega-Conotoxina GVIA
20.
Br J Pharmacol ; 105(4): 925-8, 1992 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-1380375

RESUMEN

1. The depolarizations elicited by seven neurokinin receptor agonists were examined in both rat and guinea-pig superior cervical ganglia by use of grease-gap methodology in the presence of tetrodotoxin (0.1 microM). Responses were normalised with respect to 1 microM eledoisin. 2. The rank order of agonist potency in the rat ganglia was senktide greater than substance P greater than substance P methyl ester = eleidosin = Sar-Met-substance P greater than neurokinin B greater than neurokinin A, whereas in guinea-pig superior cervical ganglion (SCG) the rank order was senktide greater than Sar-Met-substance P greater than neurokinin B = eledoisin = substance P methyl ester. The concentration-effect curves for substance P and neurokinin A in guinea-pig ganglia were biphasic which precluded the determination of meaningful potency values. 3. The maximal depolarization achieved by subtype selective ligands was different between these two species. On rat and guinea-pig SCG, the NK3-selective ligand, senktide, produced a maximal depolarization of 27% and 274% respectively, whereas the NK1-selective ligand, substance P methyl ester, produced depolarizations of 77% and 64% respectively. 4. The depolarizations induced by substance P methyl ester and senktide in either species were unaffected by atropine (1 microM), suggesting a lack of involvement of presynaptic neurokinin receptors in the generation of the response. 5. The potency of substance P methyl ester, senktide, and neurokinin A were unaffected by pretreating ganglia with the peptidase inhibitors bacitracin (40 micrograms ml-1), leupeptin (4 micrograms ml-1), and chymostatin (2 micrograms ml-1). Similarly, these peptidase inhibitors had no effect on the maximal depolarizations achieved by any of these agonists.6. It is evident that rat and guinea-pig superior cervical ganglia possess both NK, and NK3 receptors, but that their net contribution to depolarizations are different between the two species. The depolarizations in guinea-pig SCG are mediated predominantly by an NK3 subtype and in rat SCG by an NK, receptor subtype.


Asunto(s)
Ganglios Simpáticos/efectos de los fármacos , Receptores de Neurotransmisores/efectos de los fármacos , Animales , Ganglios Simpáticos/fisiología , Cobayas , Técnicas In Vitro , Masculino , Potenciales de la Membrana/efectos de los fármacos , Neuroquinina A/farmacología , Neuroquinina B/farmacología , Ratas , Ratas Endogámicas , Receptores de Neuroquinina-2 , Receptores de Neurotransmisores/clasificación , Receptores de Neurotransmisores/fisiología , Especificidad de la Especie , Sustancia P/análogos & derivados , Sustancia P/farmacología
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