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2.
Psychoneuroendocrinology ; 51: 151-63, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25313535

RESUMEN

Early life stress can alter hypothalamic pituitary adrenal (HPA) axis function. Differences in cortisol levels have been found in preterm infants exposed to substantial procedural stress during neonatal intensive care, compared to infants born full-term, but only a few studies investigated whether altered programming of the HPA axis persists past toddler age. Further, there is a dearth of knowledge of what may contribute to these changes in cortisol. This prospective cohort study examined the cortisol profiles in response to the stress of cognitive assessment, as well as the diurnal rhythm of cortisol, in children (n=129) born at varying levels of prematurity (24-32 weeks gestation) and at full-term (38-41 weeks gestation), at age 7 years. Further, we investigated the relationships among cortisol levels and neonatal procedural pain-related stress (controlling for multiple medical confounders), concurrent maternal factors (parenting stress, depressive and anxiety symptoms) and children's behavioral problems. For each aim we investigate acute cortisol response profiles to a cognitive challenge as well as diurnal cortisol patterns at home. We hypothesized that children born very preterm will differ in their pattern of cortisol secretion from children born full-term, possibly depended on concurrent child and maternal factors, and that exposure to neonatal pain-related stress would be associated with altered cortisol secretion in children born very preterm, possibly in a sex-dependent way. Saliva samples were collected from 7-year old children three times during a laboratory visit for assessment of cognitive and executive functions (pretest, mid-test, end-study day acute stress profile) and at four times over two consecutive non-school days at home (i.e. morning, mid-morning, afternoon and bedtime-diurnal rhythm profile). We found that cortisol profiles were similar in preterm and full-term children, albeit preterms had slightly higher cortisol at bedtime compared to full-term children. Importantly, in the preterm group, greater neonatal procedural pain-related stress (adjusted for morphine) was associated with lower cortisol levels on the study day (p=.044) and lower diurnal cortisol at home (p=.023), with effects found primarily in boys. In addition, child attention problems were negatively, and thought problems were positively, associated with the cortisol response during cognitive assessment on the study day in preterm children. Our findings suggest that neonatal pain/stress contributes to altered HPA axis function up to school-age in children born very preterm, and that sex may be an important factor.


Asunto(s)
Hidrocortisona/análisis , Sistema Hipotálamo-Hipofisario/fisiopatología , Dolor/fisiopatología , Sistema Hipófiso-Suprarrenal/fisiopatología , Niño , Ritmo Circadiano/fisiología , Femenino , Humanos , Recién Nacido , Recien Nacido Prematuro , Masculino , Saliva/química , Estrés Psicológico/fisiopatología
4.
Auton Neurosci ; 156(1-2): 19-26, 2010 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-20335078

RESUMEN

The inhibition of bladder sensory transmission is critical for the pharmacotherapy of urine storage symptoms. The purpose of this study is to examine the correlation between pharmacologically-induced changes in cystometric parameters and spinal c-Fos expression in anesthetized rats with bladder hyperactivity induced by the intravesical infusion of acetic acid. Animals were intravenously infused with either oxybutynin (OXY), a muscarinic receptor antagonist, tamsulosin (TAM), an alpha1-adrenoceptor antagonist, CL316243 (CL), a beta3-adrenoceptor agonist, or saline. Morphine (MOR) treatment served as a positive control to inhibit bladder afferent activity. Intermicturition intervals, micturition pressure and pressure threshold were measured after intravesical acetic acid infusion. Animals were then perfused and spinal cords were removed. Sections from the L6 spinal cord were immunostained with an anti-c-Fos antibody, and c-Fos positive cells in the dorsal region were counted. CL and MOR significantly increased intermicturition intervals, whereas OXY and TAM had no significant effect on intermicturition intervals. While TAM and MOR did not affect the micturition pressure, OXY and CL caused a significant decrease. Pressure threshold was significantly decreased by CL and increased by MOR. All drugs significantly decreased the number of c-Fos positive cells with the following order of efficacy: MOR>CL>OXT>TAM. The number of c-Fos positive cells in each animal from all treatment groups was negatively correlated with its average intermicturition interval and pressure threshold, but not with its micturition pressure. Bladder afferent activity is suppressed by several clinically proven mechanisms as measured by c-Fos expression, despite the varied effects on cystometric parameters of each pharmacological treatment.


Asunto(s)
Proteínas Proto-Oncogénicas c-fos/biosíntesis , Médula Espinal/efectos de los fármacos , Médula Espinal/metabolismo , Vejiga Urinaria/efectos de los fármacos , Vejiga Urinaria/fisiología , Animales , Dioxoles/farmacología , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Ácidos Mandélicos/farmacología , Ratas , Ratas Sprague-Dawley , Sulfonamidas/farmacología , Tamsulosina , Micción/efectos de los fármacos , Micción/genética
5.
J Gen Physiol ; 135(5): 433-48, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20421371

RESUMEN

Long QT interval syndrome (LQTS) type 1 (LQT1) has been reported to arise from mutations in the S3 domain of KCNQ1, but none of the seven S3 mutations in the literature have been characterized with respect to trafficking or biophysical deficiencies. Surface channel expression was studied using a proteinase K assay for KCNQ1 D202H/N, I204F/M, V205M, S209F, and V215M coexpressed with KCNE1 in mammalian cells. In each case, the majority of synthesized channel was found at the surface, but mutant I(Ks) current density at +100 mV was reduced significantly for S209F, which showed approximately 75% reduction over wild type (WT). All mutants except S209F showed positively shifted V(1/2)'s of activation and slowed channel activation compared with WT (V(1/2) = +17.7 +/- 2.4 mV and tau(activation) of 729 ms at +20 mV; n = 18). Deactivation was also accelerated in all mutants versus WT (126 +/- 8 ms at -50 mV; n = 27), and these changes led to marked loss of repolarizing currents during action potential clamps at 2 and 4 Hz, except again S209F. KCNQ1 models localize these naturally occurring S3 mutants to the surface of the helices facing the other voltage sensor transmembrane domains and highlight inter-residue interactions involved in activation gating. V207M, currently classified as a polymorphism and facing lipid in the model, was indistinguishable from WT I(Ks). We conclude that S3 mutants of KCNQ1 cause LQTS predominantly through biophysical effects on the gating of I(Ks), but some mutants also show protein stability/trafficking defects, which explains why the kinetic gain-of-function mutation S209F causes LQT1.


Asunto(s)
Canal de Potasio KCNQ1/genética , Síndrome de QT Prolongado/genética , Mutación Missense/genética , Potenciales de Acción/fisiología , Animales , Línea Celular , Fibroblastos/citología , Fibroblastos/fisiología , Humanos , Activación del Canal Iónico/fisiología , Canal de Potasio KCNQ1/química , Ratones , Modelos Animales , Técnicas de Placa-Clamp , Estructura Terciaria de Proteína/genética , Proteínas Tirosina Quinasas Receptoras/genética , Proteínas Tirosina Quinasas Receptoras/fisiología , Transfección
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