Defining Smallness for Gestational Age in the Early Years of the Danish Medical Birth Registry

Background: Being born small for gestational age (SGA) is associated with decreased insulin sensitivity and increased blood pressure in childhood, but the association with clinical disease in early adulthood is less certain. The Danish Medical Birth Registry has registered all births in Denmark since 1973, but due to variable data quality, data is most often used only from 1981 onwards, and birth registers in other countries may have similar problems for the early years. We wanted to examine whether the data can be used for identification of children born SGA and used in future research. Methodology/Principal Findings: All persons born between 1974 and 1996 were identified in the Danish Medical Birth Registry (n = 1.704.890). Immigrants and children without data on gestational age and birth weight were excluded, and a total of 1.348.106 children were included in the analysis. The difference between the different variables used in the history of the registry were examined, and the quality of data in the birth registry from 1974-1981 was examined and compared to subsequent years. Data on birth weight and gestational age in the early years of the registry is inconsistent, and the identification of children born SGA is inaccurate, with 49 % false-positives. The biggest source of error is due to the rough and inaccurate intervals used for gestational age. By using –3 standard deviations as a cut-off for the identification of children born SGA, the number of false-positives was reduced to 9%, while the amount of false-negatives were increased. Conclusion: Choosing –3 standard deviations for identifying children born SGA is a viable, though not optimal solution fo

Anxiolytic-like effects observed in rats exposed to the elevated zero-maze following treatment with 5-HT₂/5-HT₃/5-HT₄ ligands

The present study examined the effects of administering selective 5-HT antagonists and agonists to rats tested in the elevated zero-maze (EZM) model of anxiety. The EZM paradigm has advantages over the elevated plus-maze (EPM) paradigm with respect to measuring anxiety, yet has been utilized less frequently. Three experiments were conducted each with a diazepam control (0.25, 0.5 and 0.75 mg/kg). In the first experiment, we administered the 5-HT(2C) antagonist RS 102221 (0.5, 1.0, and 2.0 mg/kg) and 5-HT(2C) agonist MK-212 (0.25, 0.5 and 0.75 mg/kg); in the second experiment, we administered the 5-HT(3) antagonist Y-25130 (0.1, 1.0 and 3.0 mg/kg) and 5-HT(3) agonist SR 57227A (0.1, 1.0 and 3.0 mg/kg), and in the third experiment, we administered the 5-HT(4) antagonist RS 39604 (0.01, 0.1, 1.0 mg/kg) and 5-HT(4) agonist RS 67333 (0.01, 0.1 and 0.5 mg/kg). The administration of 5-HT(2/3/4) subtype antagonists all generated behavioral profiles indicative of anxiolytic-like effects in the EZM, which was apparent from examination of both traditional and ethological measures. While little effect was observed from 5-HT(2) and 5-HT(3) agonists, the 5-HT(4) agonist RS 67333 was found to produce a paradoxical anxiolytic-like effect similar to that produced by the 5-HT(4) antagonist RS 39604. We conclude by discussing the implications of these findings