RESUMEN
Despite much research, gaps remain in knowledge about the potential health effects of exposure to radiofrequency (RF) fields. This study investigated the effects of early-life exposure to pulsed long term evolution (LTE) 1,846 MHz downlink signals on innate mouse behavior. Animals were exposed for 30 min/day, 5 days/week at a whole-body average specific energy absorption rate (SAR) of 0.5 or 1 W/kg from late pregnancy (gestation day 13.5) to weaning (postnatal day 21). A behavioral tracking system measured locomotor, drinking, and feeding behavior in the home cage from 12 to 28 weeks of age. The exposure caused significant effects on both appetitive behaviors and activity of offspring that depended on the SAR. Compared with sham-exposed controls, exposure at 0.5 W/kg significantly decreased drinking frequency (P ≤ 0.000) and significantly decreased distance moved (P ≤ 0.001). In contrast, exposure at 1 W/kg significantly increased drinking frequency (P ≤ 0.001) and significantly increased moving duration (P ≤ 0.005). In the absence of other plausible explanations, it is concluded that repeated exposure to low-level RF fields in early life may have a persistent and long-term effect on adult behavior. Bioelectromagnetics. 2019;40:498-511. © 2019 The Authors. Bioelectromagnetics Published by Wiley Periodicals, Inc.
Asunto(s)
Efectos Tardíos de la Exposición Prenatal , Ondas de Radio/efectos adversos , Animales , Conducta Animal/efectos de la radiación , Peso Corporal/efectos de la radiación , Simulación por Computador , Femenino , Aprendizaje/efectos de la radiación , Masculino , Ratones , Ratones Endogámicos C57BL , Embarazo , Factores de Tiempo , Irradiación Corporal TotalRESUMEN
Although radio frequency (RF) electromagnetic fields emitted by mobile phones have received much attention, relatively little is known about the extremely low frequency (ELF) magnetic fields emitted by phones. This paper summarises ELF magnetic flux density measurements on global system for mobile communications (GSM) mobile phones, conducted as part of the MOBI-KIDS epidemiological study. The main challenge is to identify a small number of generic phone models that can be used to classify the ELF exposure for the different phones reported in the study. Two-dimensional magnetic flux density measurements were performed on 47 GSM mobile phones at a distance of 25 mm. Maximum resultant magnetic flux density values at 217 Hz had a geometric mean of 221 (+198/-104) nT. Taking into account harmonic data, measurements suggest that mobile phones could make a substantial contribution to ELF exposure in the general population. The maximum values and easily available variables were poorly correlated. However, three groups could be defined on the basis of field pattern indicating that manufacturers and shapes of mobile phones may be the important parameters linked to the spatial characteristics of the magnetic field, and the categorization of ELF magnetic field exposure for GSM phones in the MOBI-KIDS study may be achievable on the basis of a small number of representative phones. Such categorization would result in a twofold exposure gradient between high and low exposure based on type of phone used, although there was overlap in the grouping.
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Teléfono Celular/instrumentación , Campos Magnéticos , Algoritmos , Suministros de Energía Eléctrica , Europa (Continente)RESUMEN
This paper presents calculations of the induced current density in the body at 50 Hz from applied electric and magnetic fields. An extensive ensemble of 25 voxel models has been used to investigate the effects of body posture, anatomy, age and pregnancy. This set includes six adult models, eight child models and seven pregnant female models at various stages of gestation. The four postures investigated in the HPA adult model, NORMAN, were the standard position with the arms at the side, with the arms vertically above the head, the arms horizontally to the side and sitting.
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Envejecimiento/fisiología , Tamaño Corporal/fisiología , Electricidad , Modelos Biológicos , Postura/fisiología , Embarazo/fisiología , Recuento Corporal Total/métodos , Adulto , Carga Corporal (Radioterapia) , Niño , Simulación por Computador , Campos Electromagnéticos , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Adulto JovenRESUMEN
OBJECTIVE: The aim of the study was to determine the prevalence and characteristics of fetal alcohol syndrome (FAS) in a second primary school cohort in a community in South Africa. METHOD: Active case ascertainment, two-tier screening, and Institute of Medicine assessment methodology were employed among 857 first grade pupils, most born in 1993. Characteristics of children with FAS were contrasted with characteristics of a randomly selected control group from the same classrooms. Physical growth and development, dysmorphology and psychological characteristics of the children and measures of maternal alcohol use and smoking were analyzed. RESULTS: The rate of FAS found in this study is the highest yet reported in any overall community in the world, 65.2-74.2 per 1,000 children in the first grade population. These rates are 33-148 times greater than U.S. estimates and higher than in a previous cohort study in this same community (40.5-46.4 per 1,000). Detailed documentation of physical features indicates that FAS children in South Africa have characteristics similar to those elsewhere: poor growth and development, facial and limb dysmorphology, and lower intellectual functioning. Frequent, severe episodic drinking of beer and wine is common among mothers and fathers of FAS children. Their lives are characterized by serious familial, social and economic challenges, compared with controls. Heavy episodic maternal drinking is significantly associated with negative outcomes of children in the area of nonverbal intelligence but even more so in verbal intelligence, behavior and overall dysmorphology (physical anomalies). Significantly more FAS exists among children of women who were rural residents (odds ratio: 7.36, 95% confidence interval: 3.31-16.52), usually among workers on local farms. CONCLUSION: A high rate of FAS was documented in this community. Given social and economic similarities and racial admixture, we suspect that other communities in the Western Cape have rates that also are quite high.
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Países en Desarrollo , Trastornos del Espectro Alcohólico Fetal/epidemiología , Niño , Comparación Transcultural , Estudios Transversales , Femenino , Humanos , Incidencia , Recién Nacido , Inteligencia/efectos de los fármacos , Masculino , Embarazo , Población Rural/estadística & datos numéricos , Factores Socioeconómicos , SudáfricaRESUMEN
OBJECTIVE: A short course of moderately early dexamethasone therapy with a starting dose of 0.5 mg/kg/day improves lung compliance and shortens the duration of ventilatory support in preterm infants with respiratory distress syndrome (RDS). We conducted a double-blind, randomized study to evaluate whether a moderately early 14-day weaning course of low-dose dexamethasone affects adrenal function and facilitates weaning from the ventilator. PATIENTS AND METHODS: Thirty-six preterm infants with a gestational age < or =32 weeks who required ventilatory support for RDS on days 7-14 were randomized to a 14-day treatment course with dexamethasone (0.2 mg/kg/day start, tapering doses) or placebo (equivalent amounts of normal saline). Prior to the first study treatment and the day after completion of the treatment course, adrenal function was assessed from serum cortisol levels drawn before and 30 min after intravenous administration of 0.1 mg Cortrosyn. Extubation rate during treatment in both groups was compared. RESULTS: In both groups baseline serum cortisol levels decreased significantly during treatment, but stimulated cortisol levels did not change. After the 14-day treatment course, stimulated cortisol levels increased significantly from baseline levels in both groups (p<0.001), following Cortrosyn administration. More infants in the dexamethasone group were extubated within 7-14 days of study entry than in the placebo group (p<0.05). Hyperglycemia was more frequently diagnosed in the dexamethasone group and open-label dexamethasone treatment was given more frequently in the control group. CONCLUSIONS: A moderately early 14-day weaning course of low-dose dexamethasone does not significantly suppress the adrenal function of very preterm infants with RDS, but accelerates weaning from the ventilator.
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Insuficiencia Suprarrenal/inducido químicamente , Antiinflamatorios/uso terapéutico , Dexametasona/uso terapéutico , Síndrome de Dificultad Respiratoria del Recién Nacido/terapia , Desconexión del Ventilador , Glándulas Suprarrenales/efectos de los fármacos , Glándulas Suprarrenales/metabolismo , Insuficiencia Suprarrenal/sangre , Antiinflamatorios/administración & dosificación , Cosintropina/uso terapéutico , Dexametasona/administración & dosificación , Método Doble Ciego , Quimioterapia Combinada , Femenino , Humanos , Hidrocortisona/sangre , Recién Nacido , Inyecciones Intravenosas , Unidades de Cuidado Intensivo Neonatal , Masculino , Sistema Hipófiso-Suprarrenal/efectos de los fármacos , Sistema Hipófiso-Suprarrenal/metabolismo , Respiración Artificial , Síndrome de Dificultad Respiratoria del Recién Nacido/complicacionesRESUMEN
BACKGROUND: This study examined the association between prenatal alcohol exposure and attachment behavior in 4- and 5-year-old children. Prenatal alcohol exposure was hypothesized to be associated with insecure attachment behavior of the child toward the mother. It was also hypothesized that children with heavier prenatal alcohol exposure would exhibit higher levels of negative affect as well as poorer coping skills. The quality of maternal support in interaction with the child was predicted to mediate prenatal exposure effects. METHODS: Participants were 42 mother-child dyads, the majority of whom came from poverty backgrounds in which the mother was a single parent. Attachment security was measured using the Attachment Q-Set. RESULTS: Results revealed that prenatal alcohol exposure was highly related to attachment insecurity. Eighty percent of children who were exposed to alcohol during gestation were insecure, whereas 36% of unexposed children were insecure. Prenatal alcohol exposure also predicted child negative affect, which was related to lower levels of maternal emotional support of the child. However, when the mothers of the prenatally exposed children provided high levels of support, these children evidenced better coping skills and more secure attachment relations. CONCLUSIONS: Although prenatal alcohol exposure was found to relate to higher levels of insecure attachment, children of mothers who provided them with emotional support were more able to deal with frustration. These children also exhibited higher levels of attachment security. Thus, the mother's supportive presence may mediate the association between prenatal alcohol exposure and the child's security of attachment.