Deficient social and play behavior in juvenile and adult rats after neonatal cortical lesion: effects of chronic pubertal cannabinoid treatment.
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The aim of the present study was to investigate the effects of neonatal excitotoxic lesions of the medial prefrontal cortex (mPFC) on social play, social behavior unrelated to play, and self-grooming in juvenile and adult rats. We additionally examined the behavioral effects of chronic pubertal treatment with the cannabinoid agonist WIN 55,212-2 (WIN) in order to test the hypothesis that early lesions render the brain vulnerable to cannabinoid intake in later life. Neonatal mPFC lesions and pubertal WIN treatment disrupted social play, social behavior, and self-grooming in juvenile and adult rats. Additionally, we observed more social play behaviors during light cycle in WIN-treated than in vehicle-treated rats. Notably, the combination of surgery and WIN treatment disrupted social behavior in lesioned and sham-lesioned rats. The present data indicate that the mPFC is important for adequate juvenile response selection in the context of social play and might be involved in the development of adult social and nonsocial behavior. Moreover, our data add further evidence for an involvement of the cannabinoid system in anxiety and social behavior. Additive effects of neonatal surgery-induced stress or cortical lesions in combination with pubertal cannabinoid administration are also shown. The disturbances of social and nonsocial behavior in rats are comparable to symptoms of early frontal cortex damage, as well as neurodevelopmental disorders in humans, such as schizophrenia and autism. Therefore, we propose the combination of neonatal cortical lesions with chronic cannabinoid administration during puberty as an animal model for studying neuronal mechanisms of impaired social functioning in neuropsychiatric disorders. (+info)
A transactional model of parent-infant interactions in alcoholic families.
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This study examined the transactional nature of parent-infant interactions over time among alcoholic and nonalcoholic families. The sample consisted of 222 families assessed at 12, 18, and 24 months of child age. Results indicated that infant behavior did not influence parental behavior across time, but parental behavior was longitudinally predictive of infant behavior during play interactions. Higher paternal alcohol consumption at 12 months was longitudinally predictive of negative parental behavior at 24 months. Other significant risk factors included marital conflict, fathers' depression, and fathers' education. Results highlight the nested nature of risk in alcoholic families and the direction of influence from parent to child during interactions and suggest that 1 pathway to risk among these children is through negative parent-infant interactions. (+info)
Evaluation of behavioral skills training to prevent gun play in children.
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This study evaluated behavioral skills training (BST), in a multiple baseline across subjects design, for teaching firearm safety skills to 6 6- and 7-year-old children. Similar to previous research with 4- and 5-year-olds, half of the children acquired the safety skills following BST and half acquired the skills following BST plus in situ training. (+info)
Chlorpyrifos accumulation patterns for child-accessible surfaces and objects and urinary metabolite excretion by children for 2 weeks after crack-and-crevice application.
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The Children's Post-Pesticide Application Exposure Study (CPPAES) was conducted to look at the distribution of chlorpyrifos within a home environment for 2 weeks after a routine professional crack-and-crevice application and to determine the amount of the chlorpyrifos that is absorbed by a child living within the home. Ten residential homes with a 2- to 5-year-old child in each were selected for study, and the homes were treated with chlorpyrifos. Pesticide measurements were made from the indoor air, indoor surfaces, and plush toys. In addition, periodic morning urine samples were collected from each of the children throughout the 2-week period. We analyzed the urine samples for 3,5,6-trichloropyridinol, the primary urinary metabolite of chlorpyrifos, and used the results to estimate the children's absorbed dose. Average chlorpyrifos levels in the indoor air and surfaces were 26 (pretreatment)/120 (posttreatment) ng/m3 and 0.48 (pretreatment)/2.8 (posttreatment) ng/cm2, respectively, reaching peak levels between days 0 and 2; subsequently, concentrations decreased throughout the 2-week period. Chlorpyrifos in/on the plush toys ranged from 7.3 to 1,949 ng/toy postapplication, with concentrations increasing throughout the 2-week period, demonstrating a cumulative adsorption/absorption process indoors. The daily amount of chlorpyrifos estimated to be absorbed by the CPPAES children postapplication ranged from 0.04 to 4.8 microg/kg/day. During the 2 weeks after the crack-and-crevice application, there was no significant increase in the amount of chlorpyrifos absorbed by the CPPAES children. (+info)
Heat related deaths to young children in parked cars: an analysis of 171 fatalities in the United States, 1995-2002.
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OBJECTIVE: To describe the circumstances surrounding heat related deaths to young children in passenger compartments of motor vehicles. METHODS: Cases of heat related deaths to children aged +info)
Perinatal exposure to the fungicide prochloraz feminizes the male rat offspring.
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Prochloraz is a commonly used fungicide that has shown multiple mechanisms of action in vitro. It antagonizes the androgen and the estrogen receptors, agonizes the Ah receptor, and inhibits aromatase activity. In vivo prochloraz acts antiandrogenically in the Hershberger assay by reducing weights of reproductive organs, affecting androgen-regulated gene expressions, and increasing luteinizing hormone (LH) levels. The purpose of this study was to investigate reproductive toxic effects after exposure during gestation and lactation to prochloraz alone and a mixture of five pesticides (deltamethrin, methiocarb, prochloraz, simazine, and tribenuron-methyl). Prochloraz (30 mg/kg/day) or the mixture (20 mg/kg/day) was dosed to pregnant Wistar dams from gestational day (GD) 7 until postnatal day (PND) 16. Some dams were taken for cesarean section at GD 21, and others were allowed to give birth. Results showed that prochloraz and the mixture significantly reduced plasma and testicular testosterone levels in GD 21 male fetuses, whereas testicular progesterone was increased. Gestational length was increased by prochloraz. Chemical analysis of the rat breast milk showed that prochloraz was transferred to the milk. In males a significant increase of nipple retention was found, and the bulbourethral gland weight was decreased, whereas other reproductive organs were unaffected. In addition cytochrome P450 (CYP)1A activities in livers were induced by prochloraz, possibly as a result of Ah receptor activation. Behavioral studies showed that the activity level and sweet preference of adult males were significantly increased. Overall these results strongly indicate that prochloraz feminizes the male offspring after perinatal exposure, and that these effects are due, at least in part, to diminished fetal steroidogenesis. (+info)
Out on a limb: risk factors for arm fracture in playground equipment falls.
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OBJECTIVES: To investigate and quantify fall height, surface depth, and surface impact attenuation as risk factors for arm fracture in children who fall from playground equipment. DESIGN: Unmatched case control study. SETTING: Five case hospitals and 78 randomly selected control schools. PARTICIPANTS: Children aged less than 13 years in Victoria, Australia who fell from school playground equipment and landed on their arm. Cases sustained an upper limb fracture and controls had minor or no injury. A total of 402 cases and 283 controls were included. INTERVENTIONS: Children were interviewed in the playground as soon as possible after their fall. MAIN OUTCOME MEASURES: Falls were recreated on site using two validated impact test devices: a headform (measuring peak G and HIC) and a novel anthropometric arm load dummy. Equipment and fall heights, as well as surface depth and substrate were measured. RESULTS: Arm fracture risk was greatest for critical equipment heights above 1.5 m (OR 2.39, 95% CI 1.49 to 3.84, p<0.01), and critical fall heights above 1.0 m (OR 2.96, 95% CI 1.71 to 5.15, p<0.01). Peak headform deceleration below 100G was protective (OR 0.67, 95% CI 0.45 to 0.99, p = 0.04). Compliance with 20 cm surface depth recommendation was poor for both cases and controls. CONCLUSIONS: Arm fracture-specific criteria should be considered for future standards. These include surface and height conditions where critical headform deceleration is less than 100G. Consideration should also be given to reducing maximum equipment height to 1.5 m. Improved surface depth compliance and, in particular, guidelines for surface maintenance are required. (+info)
Effects of self-evaluation on preschool children's use of social interaction strategies with their classmates with autism.
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This study investigated effects of a self-evaluation procedure on preschool children's use of social interaction strategies among their classmates with autism. Three triads of children (comprised of 1 trained normally developing peer, 1 untrained peer, and 1 child with autism) participated. A multiple baseline design across subjects was used to demonstrate that peers who were taught facilitative strategies increased their use of strategies only after the self-evaluation intervention was introduced. Improvements in social behavior of children with autism was associated with peers' increased strategy use. Untrained peers demonstrated little change in their social behavior. Treatment effects were replicated when trained peers were asked to use self-evaluation with other children with autism during other play times. Self-evaluation procedures enhanced the use of social interaction strategies on the part of normally developing peers during social skills interventions. (+info)