The brain-derived neurotrophic factor VAL68MET polymorphism modulates how developmental ethanol exposure impacts the hippocampus.

Prenatal exposure to alcohol causes a wide range of deficits known as fetal alcohol spectrum disorders (FASDs). Many factors determine vulnerability to developmental alcohol exposure including timing and pattern of exposure, nutrition and genetics. Here, we characterized how a prevalent single nucleotide polymorphism in the human brain-derived neurotrophic factor (BDNF) gene (val66met) modulates FASDs severity. This polymorphism disrupts BDNF's intracellular trafficking and activity-dependent secretion, and has been linked to increased incidence of neuropsychiatric disorders such as depression and anxiety. We hypothesized that developmental ethanol (EtOH) exposure more severely affects mice carrying this polymorphism. We used transgenic mice homozygous for either valine (BDNFval/val ) or methionine (BDNFmet/met ) in residue 68, equivalent to residue 66 in humans. To model EtOH exposure during the second and third trimesters of human pregnancy, we exposed mice to EtOH in vapor chambers during gestational days 12 to 19 and postnatal days 2 to 9. We found that EtOH exposure reduces cell layer volume in the dentate gyrus and the CA1 hippocampal regions of BDNFmet/met but not BDNFval/val mice during the juvenile period (postnatal day 15). During adulthood, EtOH exposure reduced anxiety-like behavior and disrupted trace fear conditioning in BDNFmet/met mice, with most effects observed in males. EtOH exposure reduced adult neurogenesis only in the ventral hippocampus of BDNFval/val male mice. These studies show that the BDNF val66met polymorphism modulates, in a complex manner, the effects of developmental EtOH exposure, and identify a novel genetic risk factor that may regulate FASDs severity in humans.

Choroid plexus cysts do not affect fetal neurodevelopment.

OBJECTIVE: To determine whether an isolated finding of a choroid plexus cyst (CPC) during routine ultrasound is associated with altered fetal growth or development. STUDY DESIGN: Prospective, case-control study comparing 35 CPC cases to 67 controls. Neurobehavioral development assessment included 50 min long serial recordings of heart rate, motor activity and their interrelation at 24, 28, 32 and 36 weeks gestation. Growth measurement was based on three ultrasound evaluations of femur length, biparietal diameter, head circumference and abdominal circumference at initial exam, 28 and 36 weeks. RESULTS: Longitudinal analyses revealed no differences in fetal heart rate, variability or accelerations; the number or duration of fetal movements or total motor activity; nor fetal movement-fetal heart rate coupling. CPC cases had slightly smaller head and abdominal circumferences at 28 weeks, but these differences had disappeared by 36 weeks. CPC detection was more common when routine exams were conducted earlier (18.8 versus 19.5 weeks; P<0.01). CONCLUSION: Despite the presumption that CPCs with normal karyotypes are benign variants, little empirical support exists. These results indicate that CPCs detected by prenatal ultrasound do not pose or reveal a threat to fetal development.

The biochemical status of metabolites of alkane-utilizing Pseudomonas organisms.

Examination of the metabolic products formed by five alkane-utilizing Pseudomonas organisms during growth on various alkanes and on glucose as sole carbon sources indicates that many metabolites may be of predominantly synthetic origin rather than intermediary metabolites of alkane breakdown. This conclusion is supported by an examination of the effect of fluoroacetate on such fermentations.

The metabolism of n-decane by a Pseudomonas.

The growth of a Pseudomonas on n-decane was found to produce stearic acid, oleic acid, palmitic acid, palmitoleic acid, decanoic acid, octanoic acid, beta-hydroxydecanoic acid, beta-hydroxyoctanoic acid, beta-hydroxyhexanoic acid and beta-hydroxyadipic acid. Small amounts of n-decanamide and n-valeramide were also isolated. The effects of nitrogen and oxygen limitation on the formation of these products in continuous fermentations is reported.