ABSTRACT. Background. Leptin, the protein product of the ob gene, is produced by the adipocyte and seems to function as a link between adiposity, satiety, and activity. Leptin has also been found to be necessary for pubertal development, conception, and pregnancy in mice, and is increased in prepubertal children, independent of adiposity, suggesting a role in childhood growth and development. This study investigated 100 mother/newborn pairs to determine the role of leptin in neonatal development. Placental tissue was assayed for leptin mRNA to evaluate it as a source of leptin production in utero.Methods. One hundred mother/newborn pairs were enrolled in this study. Radioimmunoassay was performed for leptin on maternal venous and newborn cord blood. Leptin concentrations were measured in 43 children in Tanner stages 1 and 2 as a control group. Placental tissue was obtained from five mothers and assayed for leptin mRNA by reverse transcription/polymerase chain reaction (RT/PCR). Human placental cell lines JAR and JEG-3 were also assayed for leptin mRNA expression.Results. Leptin was present in all newborns studied at a mean concentration of 8.8 ng/mL (؎9.6 standard deviations). Leptin concentrations in cord blood correlated with newborn weight (r ‫؍‬ .51), body mass index (BMI) (r ‫؍‬ .48), and arm fat (r ‫؍‬ .42). There was no correlation between leptin and insulin. When statistically covarying for adiposity for newborns and Tanner stages 1 and 2 children, newborns had greater concentrations of leptin (mean, 10.57 ng/mL) than children (mean, 3.04 ng/mL). Leptin was present in all mothers at a mean value of 28.8 ng/mL (؎22.2 standard deviations). Leptin concentration correlated with prepregnancy BMI (r ‫؍‬ .56), BMI at time of delivery (r ‫؍‬ .74), and arm fat (r ‫؍‬ .73). Maternal leptin correlated with serum insulin (r ‫؍‬ .49). There was no correlation between maternal and newborn leptin concentrations. Thirteen percent of newborns had higher leptin concentrations than their mothers. Placental tissue from five separate placentas expressed leptin mRNA at comparable or greater levels than adipose tissue. Two human trophoblastic placental cell lines, JAR and JEG-3, also expressed leptin mRNA. Conclusions.The correlation between leptin and adiposity found in children and adults was also found in newborns. Serum leptin concentrations in newborns were increased more than three-fold compared with children in Tanner stages 1 and 2 when controlling for adiposity, suggesting that leptin concentrations in the newborn are not explained by adiposity alone. Maternal leptin concentrations correlated with measures of adiposity at delivery but did not correlate with newborn adiposity or leptin. Leptin mRNA was expressed both in placental tissue and in two human placental cell lines. These data suggest that leptin has a role in intrauterine and neonatal development and that the placenta provides a source of leptin for the growing fetus. Pediatrics 1997; 100(1). URL: http://www.pediatrics.org/cgi/content/full/ 100/1/e1; leptin, ...

This study investigated the effectiveness of graduated exposure, verbal mping skills, and their combination in treating fear of the dark in 4and 5-year-old normal children, using both be-, havioral and subjective measures of fearfulness. Only those groups which received direct exposure to the dark during treatment demonstrated significant changes in dark tolerance. Non-significant differences in dark tolerance for high versus low instructiond demand conditions in two posttests were obtained. Analysis of subjective fear ratings suggested questionable validity in the children's abilities to label subjective fearfulness. The effectiveness of behavioral techniques in modifying adult fears has been well documented (Leitenberg, 1976; Marks, 1974). However, relatively little research has been reported comparing various approaches to the treatment of fears and phobias in children (Graziano, DeGiovanni , & Garcia, 1979). Generally, approaches to treating children's fears have sought to provide either direct exposure to fear stimuli or to dter verbal or coping skills related David V. Sheslow is affiliated with the Child Diagnostic and Development Clinic, Alfred I. dubat Institute, Andrew S. Bondy is with Rutgers University, and R o s a r y 0. Nelson is with the University of North Camfina at Greensboro. Portions of this paper were presented at the meeting of the Southeastern Psychologicat Assmiation, Miami, May, 1977. Requests for reprints should be sent to: David V. Sheslow; A l f d I. duPont Institute; P. 0. Box 269; Whington, DE 19869. SpeciaI thanks are extended to the children and staff at Baynes Happy Day Nursery, Greensborn, NorthCamha, for their support and cooperation, and to Susan CorriberSheslow for her assistance in completing this study.

No abstract

No abstract

No abstract

Background. The identification of the ob gene and its adipocyte-specific protein leptin has provided the first physiologic links to the regulatory system controlling body weight. In adults, elevations of serum leptin concentrations were closely correlated with the percentage of body fat. This study investigated whether leptin concentrations were elevated in obese children and the relationship between leptin concentrations and gender, pubertal stage, and race. Methods. Seventy-seven children (44 girls and 33 boys), mean age, 11.3 years, with a body mass indices (BMIs) greater than 95% for age, race, and gender (mean BMI, 34.4) constituted the obese group. Thirty children (20 girls and 10 boys), mean age, 13.3 years, with BMIs less than 85% for age, race, and sex formed the control group. Radioimmunoassay for serum leptin was performed on a blood sample collected from each child after an overnight fast. Results. The mean serum concentration of leptin in the obese group was 38.6 (SD, 21) ng/mL compared with 7.8 (SD, 6.5) ng/mL in the control group. Serum leptin concentrations were highly correlated with BMI (r = .88). Analysis of covariance revealed a main effect for Tanner stage and gender. Conclusions. As in adults, obese children have high concentrations of serum leptin, which were highly correlated with arm fat and BMI. Increased adipose tissue in children is associated directly with serum leptin concentration. Leptin concentrations were found to vary with Tanner stage independent of adiposity. Compared with boys, girls had increased leptin concentrations independent of adiposity. It was hypothesized that children manifest a relative "leptin resistance" to support increased growth and development of reproductive capacity.

No abstract

No abstract