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1.
J Hum Nutr Diet ; 32(6): 781-788, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31334579

RESUMEN

BACKGROUND: Novel and innovative imaging methods that rapidly estimate body fat percentage (%BF) are publicly available, yet little is known about their accuracy. The present study evaluated the test-retest reliability of a two-dimensional iPad (Apple, Inc., Cupertino, CA, USA) application (2D APP) and a three-dimensional body scanner (3D SCAN) for estimating %BF and compared both imaging methods with air displacement plethysmography (Bod Pod; Cosmed USA, Inc., Concord, CA, USA). METHODS: Seventy-nine adults (37 female, 42 male) varying widely in age [mean (SD), range] [32.9 (12.4), 18-65 years] and body mass index [25.0 (4.9), 18.2-41.8 kg m-2 ] were measured with the Bod Pod and twice with the 3D SCAN and the 2D APP in a repeated-measures design. RESULTS: Test-retest reliability was excellent for both the 2D APP (intraclass correlation = 0.993) and the 3D SCAN (intraclass correlation = 0.993) with the SEM <1% BF for both methods. Although the three methods were highly correlated with each other (r = 0.857-0.923), the mean %BF estimations were significantly different (P = 0.001). The 2D APP [19.9 (8.2)%BF] underestimated the Bod Pod value [21.9 (9.4)%BF] and the 3D SCAN [24.0 (6.8)%BF] overestimated. Additionally, the SE of estimate and total error exceeded 4% BF for both 2D APP and 3D SCAN, and both methods tended to overestimate lean participants and underestimate fat participants. CONCLUSIONS: Although highly reliable, neither the 2D APP, nor the 3D SCAN provided valid estimates of %BFBod Pod .


Asunto(s)
Composición Corporal , Diagnóstico por Imagen/instrumentación , Diagnóstico por Imagen/métodos , Pletismografía/métodos , Adiposidad , Adolescente , Adulto , Anciano , Índice de Masa Corporal , Computadores , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fotograbar/instrumentación , Fotograbar/métodos , Reproducibilidad de los Resultados , Adulto Joven
2.
J Intern Med ; 277(2): 260-271, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24345063

RESUMEN

OBJECTIVES: To address the diagnostic value of circulating microRNAs (miRNAs) in patients presenting with acute chest pain. DESIGN: In a prospective, international, multicentre study, six miRNAs (miR-133a, miR-208b, miR-223, miR-320a, miR-451 and miR-499) were simultaneously measured in a blinded fashion in 1155 unselected patients presenting with acute chest pain to the emergency department. The final diagnosis was adjudicated by two independent cardiologists. The clinical follow-up period was 2 years. RESULTS: Acute myocardial infarction (AMI) was the adjudicated final diagnosis in 224 patients (19%). Levels of miR-208b, miR-499 and miR-320a were significantly higher in patients with AMI compared to those with other final diagnoses. MiR-208b provided the highest diagnostic accuracy for AMI (area under the receiver operating characteristic curve 0.76, 95% confidence interval 0.72-0.80). This diagnostic value was lower than that of the fourth-generation cardiac troponin T (cTnT; 0.84) or the high-sensitivity cTnT (hs-cTnT; 0.94; both P < 0.001 for comparison). None of the six miRNAs provided added diagnostic value when combined with cTnT or hs-cTnT (ns for the comparison of combinations vs. cTnT or hs-cTnT alone). During follow-up, 102 (9%) patients died. Levels of MiR-208b were higher in patients who died within 30 days, but the prognostic accuracy was low to moderate. None of the miRNAs predicted long-term mortality. CONCLUSION: The miRNAs investigated in this study do not seem to provide incremental diagnostic or prognostic value in patients presenting with suspected AMI.


Asunto(s)
Dolor en el Pecho/etiología , MicroARNs/sangre , Infarto del Miocardio/diagnóstico , Troponina T/sangre , Enfermedad Aguda , Anciano , Biomarcadores/sangre , Índice de Masa Corporal , Diagnóstico Diferencial , Diagnóstico Precoz , Electrocardiografía , Servicio de Urgencia en Hospital , Femenino , Estudios de Seguimiento , Humanos , Estimación de Kaplan-Meier , Luxemburgo , Masculino , Persona de Mediana Edad , Infarto del Miocardio/sangre , Infarto del Miocardio/complicaciones , Infarto del Miocardio/mortalidad , Valor Predictivo de las Pruebas , Pronóstico , Estudios Prospectivos , Medición de Riesgo , Factores de Riesgo , Sensibilidad y Especificidad , Suiza
3.
Eur Cell Mater ; 28: 358-71, 2014 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-25350251

RESUMEN

The object of this study was to elucidate the role of Ca++ signalling in the chondrogenic response of mesenchymal stem cells (MSCs) to hydrostatic pressure (HP). MSCs were seeded into agarose hydrogels, subjected to HP or kept in free swelling conditions, and were cultured either with or without pharmacological inhibitors of Ca++ mobility and downstream targets. Chelating free Ca++, inhibiting voltage-gated calcium channels, and depleting intracellular calcium storessuppressed the beneficial effect of HP on chondrogenesis, indicating that Ca++ mobility may play an important role in the mechanotransduction of HP. However, inhibition of stretch-activated calcium channels in the current experiment yielded similar results to the control group, suggesting that mechanotransduction of HP is distinct from loads that generate cell deformations. Inhibition of the downstream targets calmodulin, calmodulin kinase II, and calcineurin all knocked down the effect of HP on chondrogenesis, implicating these targets in MSCs response to HP. All of the pharmacological inhibitors that abolished the chondrogenic response to HP also maintained a punctate vimentin organisation in the presence of HP, as opposed to the mechanoresponsive groups where the vimentin structure became more diffuse. These results suggest that Ca++ signalling may transduce HP via vimentin adaptation to loading.


Asunto(s)
Señalización del Calcio , Condrogénesis , Células Madre Mesenquimatosas/metabolismo , Animales , Bloqueadores de los Canales de Calcio/farmacología , Quelantes del Calcio/farmacología , Células Cultivadas , Presión Hidrostática , Mecanotransducción Celular , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/fisiología , Porcinos , Vimentina/metabolismo
4.
Artículo en Francés | MEDLINE | ID: mdl-25011203

RESUMEN

Percutaneous aortic valve replacement (TAVI) is one of the most innovative procedure in interventional cardiology. The Direct Flow Medical transcatheter aortic valve (DFM) is a new nonmetallic valve which allows perfect repositioning and valve retrieval prior to the final deployment. This study is a prospective non-randomized evaluation of the DFM system in the Luxembourg registry. The study focused on 15 patients who received between March 2013 and October 2013 a percutaneous aortic valve replacement by DFM prosthesis. All clinical and echocardiographic data have been collected prospectively. Fifteen inoperable patients with severe aortic stenosis were evaluated. The average age of our population was 83 +/- 4.16 years, mean STS score was 16%. 46% of patients were in NYHA class III and 33.3% in NYHA class IV. Mean ejection fraction was 59% +/- 12.7, the average mean gradient was 52.86 +/- 18.5 mm Hg and mean aortic orifie was 0.63 +/- 0.15 cm2. Procedural success rate was 100%. The mean trans- valvular gradient decreased from 52.86 +/- 18.5 mm Hg to 12 +/- 4.2 mm Hg (p < 0.001). The average hospital stay was 14 +/- 7.6 days. The non-fatal major event rate at one month was 33.3%. The mortality rate at one month was limited to 6.6%. These results allow us to confirm the efficacy and safety of the DFM valve.


Asunto(s)
Estenosis de la Válvula Aórtica/cirugía , Válvula Aórtica/cirugía , Implantación de Prótesis de Válvulas Cardíacas/métodos , Prótesis Valvulares Cardíacas , Anciano , Anciano de 80 o más Años , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Humanos , Luxemburgo , Complicaciones Posoperatorias , Estudios Prospectivos , Sistema de Registros , Resultado del Tratamiento , Ultrasonografía
5.
Eur Cell Mater ; 25: 167-78, 2013 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-23389751

RESUMEN

The objective of this study was to examine the interplay between matrix stiffness and hydrostatic pressure (HP) in regulating chondrogenesis of mesenchymal stem cells (MSCs) and to further elucidate the mechanotransductive roles of integrins and the cytoskeleton. MSCs were seeded into 1 %, 2 % or 4 % agarose hydrogels and exposed to cyclic hydrostatic pressure. In a permissive media, the stiffer hydrogels supported an osteogenic phenotype, with little evidence of chondrogenesis observed regardless of the matrix stiffness. In a chondrogenic media, the stiffer gels suppressed cartilage matrix production and gene expression, with the addition of RGDS (an integrin blocker) found to return matrix synthesis to similar levels as in the softer gels. Vinculin, actin and vimentin organisation all adapted within stiffer hydrogels, with the addition of RGDS again preventing these changes. While the stiffer gels inhibited chondrogenesis, they enhanced mechanotransduction of HP. RGDS suppressed the mechanotransduction of HP, suggesting a role for integrin binding as a regulator of both matrix stiffness and HP. Intermediate filaments also appear to play a role in the mechanotransduction of HP, as only vimentin organisation adapted in response to this mechanical stimulus. To conclude, the results of this study demonstrate that matrix density and/or stiffness modulates the development of the pericellular matrix and consequently integrin binding and cytoskeletal structure. The study further suggests that physiological cues such as HP enhance chondrogenesis of MSCs as the pericellular environment matures and the cytoskeleton adapts, and points to a novel role for vimentin in the transduction of HP.


Asunto(s)
Citoesqueleto de Actina/fisiología , Diferenciación Celular , Matriz Extracelular/fisiología , Filamentos Intermedios/fisiología , Células Madre Mesenquimatosas/fisiología , Animales , Fenómenos Biomecánicos , Técnicas de Cultivo de Célula , Células Cultivadas , Condrogénesis , Colágeno/metabolismo , Medios de Cultivo , Módulo de Elasticidad , Glicosaminoglicanos/metabolismo , Hidrogeles , Presión Hidrostática , Mecanotransducción Celular , Microtúbulos/fisiología , Sus scrofa , Tubulina (Proteína)/metabolismo , Vimentina/metabolismo , Vinculina/metabolismo
6.
Eat Weight Disord ; 17(1): e54-6, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22751272

RESUMEN

Change in weight and body composition was assessed over a six-week holiday period. Baseline testing occurred the Monday or Tuesday prior to Thanksgiving Day (November 24 or 25, 2008), and the post-holiday assessment was the Monday or Tuesday after New Year's Day (January 5 or 6, 2009). Thirteen men and 21 women ranging in age from 23-61 years completed the study. The majority of participants (24 of 34) perceived that they had gained weight, and four did gain ≥2 kg. However, despite some changes to dietary and exercise habits, on average there was no difference between pre-holiday weight (74.0±17.8 kg) and post-holiday weight (73.9±18.1 kg), nor between pre-holiday body fat percentage (25.4±9.0%) and post-holiday body fat percentage (25.4±8.9%). Despite a perception of substantial weight gain, body weight and body fat remained unchanged over a six-week holiday period.


Asunto(s)
Composición Corporal , Imagen Corporal , Vacaciones y Feriados , Aumento de Peso , Pérdida de Peso , Adulto , Ejercicio Físico , Conducta Alimentaria , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad
7.
Artículo en Inglés | MEDLINE | ID: mdl-22272444

RESUMEN

BACKGROUND: Intracoronary infusion of autologous bone marrow cells (CTX) has been shown to improve myocardial function in post infarct patients and in patients with chronic ischemic cardiomyopathy. Long term results of CTX are unknown. METHODS AND RESULTS: In this small pilot study, eleven patients with chronic ischemic cardiomyopathy and ejection fraction (EF) of 19 +/- 1% were treated with CTX and followed for 7 years. Four patients died during follow-up, all because of progressive heart failure. All patients received an implantable cardioverter defibrillator (ICD) during the course of the study but only 1 patients developed ventricular tachycardia after CTX. One patient received resynchronization therapy. The overall clinical benefit of CTX was modest (NYHA 3.0 +/- 0.1 pre and 2.5 +/- 0.2 post CTX, p= 0.06). CTX was not associated with reverse remodeling. However, left ventricular EF (19 +/- 1% pre and 18 +/- 6% post) and left ventricular end-diastolic volumes (289 +/- 71 ml pre and 294 +/- 123 ml post) remained remarkably stable over 7-year follow-up in the survivors of this very sick population. CONCLUSIONS: During 7-year follow-up, CTX was associated with stabilization of EF and ventricular volumes but without significant clinical benefit or evidence of reverse remodeling.


Asunto(s)
Trasplante de Médula Ósea , Cardiomiopatías/terapia , Isquemia Miocárdica/terapia , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Volumen Sistólico , Trasplante Autólogo , Disfunción Ventricular Izquierda/terapia
8.
Science ; 274(5288): 790-2, 1996 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-8864121

RESUMEN

Photoperiodic responses, such as the daylength-dependent control of reproductive development, are associated with a circadian biological clock. The photoperiod-insensitive early-flowering 3 (elf3) mutant of Arabidopsis thaliana lacks rhythmicity in two distinct circadian-regulated processes. This defect was apparent only when plants were assayed under constant light conditions. elf3 mutants retain rhythmicity in constant dark and anticipate light/dark transitions under most light/dark regimes. The conditional arrhythmic phenotype suggests that the circadian pacemaker is intact in darkness in elf3 mutant plants, but the transduction of light signals to the circadian clock is impaired.


Asunto(s)
Arabidopsis/fisiología , Ritmo Circadiano , Luz , Fotoperiodo , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Oscuridad , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Movimiento , Mutación , Fenotipo , Proteínas del Complejo del Centro de Reacción Fotosintética/genética , Hojas de la Planta/fisiología , Plantas Modificadas Genéticamente
9.
Artículo en Francés | MEDLINE | ID: mdl-19999622

RESUMEN

INTRODUCTION: Left Ventricular twist (LV twist) is defined as the apical counter-clockwise rotation relative to the clockwise basal rotation. It has been shown that LV twist decreases after myocardial infarction (MI) and that it is well correlated with left ventricular ejection fraction. Most studies have only evaluated anterior wall MI. The aim of our study was to determine whether LV twist is dependent on the infarct territory (anterior vs. inferior) and whether there is a correlation between LV twist and matrix metalloproteinase-9, a marker of LV remodeling. METHODS: We measured LV twist using echocardiography with 2D speckle tracking in patients with acute MI and in a control group. RESULTS: We evaluated 27 controls and 35 patients with acute MI, 15 with anterior wall and 20 with inferior wall MI. LV twist was significantly decreased after MI, compared to the control group (10.93 +/- 2.05 vs 15.5 +/- 2.29; p = 0.003). There was no difference between anterior and inferior MI. LV rotation was decreased in the infarct area. We did not observe a correlation between LV twist and MMP-9, or creatine phosphokinase. CONCLUSION: With this study we confirm that LV twist decreases after acute MI. Moreover, we show that LV apical rotation is mostly decreased after large anterior MI. As apical rotation is important for ejection and aspiration (untwisting), this could be a possible mechanism of LV dysfunction after MI.


Asunto(s)
Ventrículos Cardíacos/fisiopatología , Infarto del Miocardio/fisiopatología , Adulto , Infarto de la Pared Anterior del Miocardio/fisiopatología , Ecocardiografía , Humanos , Infarto de la Pared Inferior del Miocardio/fisiopatología , Infarto del Miocardio/diagnóstico por imagen , Isquemia Miocárdica/diagnóstico por imagen , Isquemia Miocárdica/fisiopatología , Valores de Referencia , Rotación , Disfunción Ventricular Izquierda/etiología
10.
Meat Sci ; 155: 109-114, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31103942

RESUMEN

The purpose of this study was to determine the effect of captive bolt lengths on penetration hole characteristics, brain damage, and specified risk material (SRM) dispersal. Cattle were stunned with a pneumatic captive bolt stunner using: standard (15.2 cm; STRD), medium (16.5 cm; MED), or long (17.8 cm; LON) bolts. Heads (N = 293) and exsanguination blood (N = 103) were collected for analyses. Penetration hole diameter and depth differed by treatment (P ≤ 0.004); both parameters were greatest for LON (P < 0.05). Presence of damage in frontal, parietal, and occipital lobes, olfactory bulb, and collective area including the corpus callosum, fornix and thalamus were impacted by treatment (P < 0.003). Treatment did not impact SRM dispersal (P = 0.33), determined by presence of glial acidic fibrillary protein. Data suggest that bolt length affects both the extent of brain damage and the specific structures damaged but all bolt lengths are successful in causing substantial brain damage and subsequent insensibility.


Asunto(s)
Mataderos , Lesiones Traumáticas del Encéfalo/patología , Inmovilización/métodos , Bienestar del Animal , Animales , Bovinos , Proteína Ácida Fibrilar de la Glía/sangre , Traumatismos Penetrantes de la Cabeza/veterinaria , Inmovilización/instrumentación
11.
Plant Cell ; 3(9): 877-892, 1991 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12324621

RESUMEN

We present the initial phenotypic characterization of an Arabidopsis mutation, terminal flower 1-1 (tfl1-1), that identifies a new genetic locus, TFL1. The tfl1-1 mutation causes early flowering and limits the development of the normally indeterminate inflorescence by promoting the formation of a terminal floral meristem. Inflorescence development in mutant plants often terminates with a compound floral structure consisting of the terminal flower and one or two subtending lateral flowers. The distal-most flowers frequently contain chimeric floral organs. Light microscopic examination shows no structural aberrations in the vegetative meristem or in the inflorescence meristem before the formation of floral buttresses. The wild-type appearance of lateral flowers and observations of double mutant combinations of tfl1-1 with the floral morphogenesis mutations apetala 1-1 (ap1-1), ap2-1, and agamous (ag) suggest that the tfl1-1 mutation does not affect normal floral meristems. Secondary flower formation usually associated with the ap1-1 mutation is suppressed in the terminal flower, but not in the lateral flowers, of tfl1-1 ap1-1 double mutants. Our results suggest that tfl1-1 perturbs the establishment and maintenance of the inflorescence meristem. The mutation lies on the top arm of chromosome 5 approximately 2.8 centimorgans from the restriction fragment length polymorphism marker 217.

12.
Plant Cell ; 5(6): 639-655, 1993 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12271079

RESUMEN

In Arabidopsis, floral meristems arise in continuous succession directly on the flanks of the inflorescence meristem. Thus, the pathways that regulate inflorescence and floral meristem identity must operate both simultaneously and in close spatial proximity. The TERMINAL FLOWER 1 (TFL1) gene of Arabidopsis is required for normal inflorescence meristem function, and the LEAFY (LFY), APETALA 1 (AP1), and APETALA 2 (AP2) genes are required for normal floral meristem function. We present evidence that inflorescence meristem identity is promoted by TFL1 and that floral meristem identity is promoted by parallel developmental pathways, one defined by LFY and the other defined by AP1/AP2. Our analysis suggests that the acquisition of meristem identity during inflorescence development is mediated by antagonistic interactions between TFL1 and LFY and between TFL1 and AP1/AP2. Based on this study, we propose a simple model for the genetic regulation of inflorescence development in Arabidopsis. This model is discussed in relation to the proposed interactions between the inflorescence and the floral meristem identity genes and in regard to other genes that are likely to be part of the genetic hierarchy regulating the establishment and maintenance of inflorescence and floral meristems.

13.
Br J Pharmacol ; 173(1): 88-102, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26406609

RESUMEN

BACKGROUND AND PURPOSE: Adenosine has been proposed to exert anti-hypertrophic effects. However, the precise regulation and the role of the different adenosine receptor subtypes in the heart and their effects on hypertrophic signalling are largely unknown. We aimed to characterize expression and function of adenosine A1 receptors following hypertrophic stimulation in vitro and in vivo. EXPERIMENTAL APPROACH: Pro-hypertrophic stimuli and adenosine A1 receptor stimulation of neonatal rat cardiomyocytes and male C57/Bl6 mice, sc. drug administration, real-time PCR, (3) [H]-leucine-incorporation assay, immunostaining, tissue staining, Western blots, gravimetric analyses and echocardiography were applied in this study. KEY RESULTS: In neonatal rat cardiomyocyte cultures, phenylephrine, but not angiotensin II or insulin-like growth factor 1 (IGF1), up-regulated adenosine A1 receptors concentration-dependently. The hypertrophic phenotype (cardiomyocyte size, sarcomeric organization, total protein synthesis, c-fos expression) mediated by phenylephrine (10 µM), but not that by angiotensinII (1 µM) or IGF1 (20 ng·mL(-1) ), was counteracted by the selective A1 receptor agonist, N6-cyclopentyladenosine. In C57/BL6 mice, continuous N6-cyclopentyladenosine infusion (2 mg·kg(-1) ·day(-1) ; 21 days) blunted phenylephrine (120 mg·kg(-1) ·day(-1) ; 21 days) induced hypertrophy (heart weight, cardiomyocyte size and fetal genes), fibrosis, MMP 2 up-regulation and generation of oxidative stress - all hallmarks of maladaptive remodelling. Concurrently, phenylephrine administration increased expression of adenosine A1 receptors. CONCLUSIONS AND IMPLICATIONS: We have presented evidence for a negative feedback mechanism attenuating pathological myocardial hypertrophy following α1 -adrenoceptor stimulation. Our results suggest adenosine A1 receptors as potential targets for therapeutic strategies to prevent transition from compensated myocardial hypertrophy to decompensated heart failure due to chronic cardiac pressure overload.


Asunto(s)
Agonistas del Receptor de Adenosina A1/farmacología , Agonistas de Receptores Adrenérgicos alfa 1/efectos adversos , Cardiomegalia/prevención & control , Fibrosis/prevención & control , Receptor de Adenosina A1/metabolismo , Adenosina/análogos & derivados , Adenosina/farmacología , Angiotensina II/farmacología , Animales , Animales Recién Nacidos , Técnicas de Cultivo de Célula , Relación Dosis-Respuesta a Droga , Factor I del Crecimiento Similar a la Insulina/farmacología , Masculino , Metaloproteinasa 2 de la Matriz/metabolismo , Ratones , Miocitos Cardíacos/metabolismo , Estrés Oxidativo/efectos de los fármacos , Fenilefrina/antagonistas & inhibidores , Fenilefrina/farmacología , Ratas , Regulación hacia Arriba/efectos de los fármacos
14.
Genetics ; 149(2): 597-605, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9611176

RESUMEN

A new mutant of Arabidopsis thaliana that initiates flowering early and terminates the inflorescence with floral structures has been identified and named terminal flower2 (tfl2). While these phenotypes are similar to that of the terminal flower1 (tfl1) mutant, tfl2 mutant plants are also dwarfed in appearance, have reduced photoperiod sensitivity and have a more variable terminal flower structure. Under long-day and short-day growth conditions tfl1 tfl2 double mutants terminate the inflorescence without development of lateral flowers; thus, unlike tfl1 single mutants the double mutant inflorescence morphology is not affected by day length. The enhanced phenotype of the double mutant suggests that TFL2 acts in a developmental pathway distinct from TFL1. The complex nature of the tfl2 single mutant phenotype suggests that TFL2 has a regulatory role more global than that of TFL1. Double mutant analysis of tfl2 in combination with mutant alleles of the floral meristem identity genes LEAFY and APETALA1 demonstrates that TFL2 function influences developmental processes controlled by APETALA1, but not those regulated by LEAFY. Thus, the TFL2 gene product appears to have a dual role in regulating meristem activity, one being to regulate the meristem response to light signals affecting the development of the plant and the other being the maintenance of inflorescence meristem identity.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis/genética , Genes de Plantas/fisiología , Meristema/genética , Reproducción/genética , Arabidopsis/crecimiento & desarrollo , Proteínas de Homeodominio/genética , Proteínas de Dominio MADS , Meristema/crecimiento & desarrollo , Mutación/genética , Fenotipo , Proteínas de Plantas/genética
15.
Am J Psychiatry ; 148(10): 1329-35, 1991 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-1897612

RESUMEN

OBJECTIVE: Because women with late luteal phase dysphoric disorder (LLPDD) experience symptomatic affective states predictably, they can be studied to determine whether there are biological findings related solely to the clinically symptomatic state. The authors sought to answer the question, Does body temperature change with affective state? METHOD: The core body temperature and motor activity patterns of 10 women with premenstrual syndrome (PMS), six of whom also met criteria for LLPDD, and no other psychological or medical illness were compared to those of six women with chronic, noncyclic dysphoria and six asymptomatic comparison women at four phases of the menstrual cycle. RESULTS: The nocturnal temperatures of the women with PMS/LLPDD were significantly higher than those of the comparison subjects across the entire menstrual cycle, but there were no differences in nocturnal activity levels. The women with noncyclic dysphoria had a mean nocturnal temperature in the follicular phase as high as that of the women with PMS/LLPDD. The temperatures of all women were higher in the luteal phase than in the follicular phase. CONCLUSIONS: These findings suggest that in the future investigators should document menstrual cycle phase in all female subjects and, when studying body temperature, should carefully monitor symptomatic state in comparison subjects.


Asunto(s)
Temperatura Corporal/fisiología , Ritmo Circadiano/fisiología , Síndrome Premenstrual/fisiopatología , Adulto , Regulación de la Temperatura Corporal , Femenino , Fase Folicular/fisiología , Humanos , Fase Luteínica/fisiología , Ciclo Menstrual/fisiología , Monitoreo Fisiológico , Actividad Motora/fisiología
16.
Am J Clin Nutr ; 71(6): 1392-402, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10837277

RESUMEN

Biological differences exist in the body composition of blacks and whites. We reviewed literature on the differences and similarities between the 2 races relative to fat-free body mass (water, mineral, and protein), fat patterning, and body dimensions and proportions. In general, blacks have a greater bone mineral density and body protein content than do whites, resulting in a greater fat-free body density. Additionally, there are racial differences in the distribution of subcutaneous fat and the length of the limbs relative to the trunk. The possibility that these differences are a result of ethnicity rather than of race is also examined. Because most equations that predict relative body fat were derived from predominantly white samples, biological variation between the races in these body-composition indexes has practical significance. Systematic error can result in the inaccurate estimation of the relative body fat of blacks, and therefore of definitions of obesity, if these inherent differences are ignored.


Asunto(s)
Población Negra , Composición Corporal , Población Blanca , Constitución Corporal , Agua Corporal , Densidad Ósea , Humanos , Minerales , Proteínas
17.
Sleep ; 21(2): 207-12, 1998 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-9542804

RESUMEN

Wrist actigraphy is increasingly used to track circadian rest-activity cycles and to identify states of wakefulness and sleep, yet the measurement characteristics of activity recorders have never been compared. Two widely used recorders are compared here: the MotionLogger from Ambulatory Monitoring, Inc (AM) and the Gaehwiler (G). They were worn together on the same wrist for periods averaging 41.5 hours by five members of a research team. Activity counts were stored every half-minute. Pairwise comparisons between recorders of each type showed both types to be reliable. Each also validly detected circadian rest/activity cycles. Both types suffered, however, from insensitivity. For the lower 75% of activity levels, the variance of data from the G was indeed so small as to be essentially uninformative. Since these levels include over 95% of all nocturnal data, the G must be less sensitive than the AM to small nocturnal movements, including those signifying arousal. An additional difference is that data from the AM but not the G were distributed in biphasic fashion. Biphasic activity levels are consistent with the common assumption that activity/wakefulness and rest/sleep are distinct neurobehavioral states. As the use of actigraphy increases, the important differences found here between two leading instruments point to an urgent need for standards by which activity recorders can be compared. Aspects of instrument design that could be quantitatively rated are reliability, validity, ruggedness and artifact rejection.


Asunto(s)
Ritmo Circadiano/fisiología , Actividad Motora/fisiología , Sueño REM/fisiología , Vigilia/fisiología , Humanos
18.
Sleep ; 15(3): 202-11, 1992 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-1621020

RESUMEN

Six unmedicated narcoleptic subjects and nine normal controls lived in a temporal isolation laboratory for 18-22 days. They were permitted to "free-run" for the last 9-13 days. Brief cognitive and motor performance tests were repeated on average six times per subjective day. They consisted of serial search, complex verbal reasoning tasks and manual dexterity of each hand. Only minor differences in performance were found between the narcoleptic subjects and controls. Narcoleptic subjects showed mild impairment of accuracy on the search task that could be explained by occasional lapses and an afternoon dip in performance. Narcoleptic subjects also tended to perform some tasks more slowly, but the group differences were not significant. Neither speed nor accuracy of performance of narcoleptic subjects decreased over the course of the experiment. By one standard of performance, therefore, all or nearly all of the sleep need of these subjects was met by the sleep they obtained in the laboratory. That amount, in turn, did not exceed the total sleep obtained by the normal controls. Significant time-of-day effects were found in narcoleptic subjects for speed of verbal reasoning (progressive slowing over the course of the day), manual dexterity (fluctuations in speeds) and accuracy of serial search (afternoon dip). These variations in performance could not be attributed to changes in core body temperature or to occurrences of naps or meals.


Asunto(s)
Ritmo Circadiano , Narcolepsia/psicología , Pruebas Neuropsicológicas , Desempeño Psicomotor , Fases del Sueño , Aislamiento Social , Vigilia , Adulto , Anciano , Nivel de Alerta , Atención , Temperatura Corporal , Cataplejía/diagnóstico , Cataplejía/psicología , Formación de Concepto , Conducta Alimentaria , Femenino , Humanos , Masculino , Persona de Mediana Edad , Narcolepsia/diagnóstico , Solución de Problemas
19.
Sleep ; 15(1): 28-40, 1992 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-1557592

RESUMEN

Six healthy young men and eight early middle-aged men were isolated from environmental time cues for 15 days. For the first 6-7 days (one or two nights adaptation, four nights baseline), their sleep and meals were scheduled to approximate their habitual patterns. Their daily routines were then shifted 6 hours earlier by terminating the sixth or seventh sleep episode 6 hours early. The new schedules were followed for the next 8 or 9 days. Important age-related differences in adjustment to this single 6-hour schedule shift were found. For the first 4-day interval after the shift, middle-aged subjects had larger increases of waking time during the sleep period and earlier termination of sleep than young subjects. They also reported larger decreases in alertness and well-being and larger increases in sleepiness, weariness and effort required to perform daily functions. The rate of adjustment of the circadian core temperature rhythm to the new schedule did not differ between groups. These results suggest that the symptoms reported by the middle-aged subjects may be due mainly to difficulty maintaining sleep at early times of the circadian day. The compensatory response to sleep deprivation may also be less robust in middle-aged individuals traveling eastbound.


Asunto(s)
Envejecimiento/psicología , Ritmo Circadiano , Privación de Sueño , Fases del Sueño , Viaje , Adolescente , Adulto , Humanos , Luz , Masculino , Persona de Mediana Edad , Tiempo de Reacción , Sueño REM
20.
J Am Geriatr Soc ; 41(12): 1353-60, 1993 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8227919

RESUMEN

OBJECTIVE: To test the effectiveness of a nursing-centered intervention to prevent functional decline among hospitalized elderly medical patients. DESIGN: Prospective cohort study with stratified and matched cohort analyses. SETTING: General medicine wards of a university teaching hospital. PATIENTS: Two hundred sixteen patients aged > or = 70 years (85 intervention and 131 control patients). INTERVENTION: The intervention included identification and surveillance of frail older patients, twice-weekly rounds of the Geriatric Care Team, and a nursing-centered educational program. MAIN OUTCOME MEASURE: Functional decline, defined as a net decline in five activities of daily living (ADLs). RESULTS: In stratified analyses, the intervention resulted in a beneficial effect with a relative risk of 0.82 (95% confidence interval [CI] 0.54 to 1.24) in patients (n = 106) with one of four geriatric target conditions at baseline (eg, delirium, functional impairment, incontinence, and pressure sores). The intervention had no effect in patients without target conditions at baseline (n = 110); thus, this subgroup was excluded from further analyses. When patients were matched on number of target conditions and risk for functional decline at baseline (n = 66), the intervention resulted in a significant beneficial effect, with a reduction in functional decline from 64% in controls to 41% in the intervention group, for a relative risk of 0.64 (95% CI, 0.43 to 0.96). The intervention group had significantly less decline in ADL score and in individual ADLs than control subjects. Specific interventions aimed at maximizing function, such as physical therapy, were received more often by intervention patients; however, the beneficial effects of the intervention were achieved without increasing per-day hospital costs. CONCLUSIONS: The intervention appears effective to decrease functional decline in targeted elderly hospitalized medical patients.


Asunto(s)
Actividades Cotidianas , Enfermería Geriátrica/organización & administración , Modelos de Enfermería , Servicio de Enfermería en Hospital/organización & administración , Grupo de Atención al Paciente , Anciano , Anciano de 80 o más Años , Connecticut , Femenino , Evaluación Geriátrica , Hospitales con más de 500 Camas , Hospitales Universitarios/organización & administración , Humanos , Masculino , Evaluación de Resultado en la Atención de Salud , Estudios Prospectivos
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