The Arf6 activator Efa6/PSD3 confers regional specificity and modulates ethanol consumption in Drosophila and humans.

Ubiquitously expressed genes have been implicated in a variety of specific behaviors, including responses to ethanol. However, the mechanisms that confer this behavioral specificity have remained elusive. Previously, we showed that the ubiquitously expressed small GTPase Arf6 is required for normal ethanol-induced sedation in adult Drosophila. Here, we show that this behavioral response also requires Efa6, one of (at least) three Drosophila Arf6 guanine exchange factors. Ethanol-naive Arf6 and Efa6 mutants were sensitive to ethanol-induced sedation and lacked rapid tolerance upon re-exposure to ethanol, when compared with wild-type flies. In contrast to wild-type flies, both Arf6 and Efa6 mutants preferred alcohol-containing food without prior ethanol experience. An analysis of the human ortholog of Arf6 and orthologs of Efa6 (PSD1-4) revealed that the minor G allele of single nucleotide polymorphism (SNP) rs13265422 in PSD3, as well as a haplotype containing rs13265422, was associated with an increased frequency of drinking and binge drinking episodes in adolescents. The same haplotype was also associated with increased alcohol dependence in an independent European cohort. Unlike the ubiquitously expressed human Arf6 GTPase, PSD3 localization is restricted to the brain, particularly the prefrontal cortex (PFC). Functional magnetic resonance imaging revealed that the same PSD3 haplotype was also associated with a differential functional magnetic resonance imaging signal in the PFC during a Go/No-Go task, which engages PFC-mediated executive control. Our translational analysis, therefore, suggests that PSD3 confers regional specificity to ubiquitous Arf6 in the PFC to modulate human alcohol-drinking behaviors.

Effect of human milk formula with bovine colostrum supplementation on bone mineral density in infant cynomolgus macaques.

Insulin-like growth factor 1 (IGF1) is a regulator of human growth during infancy and childhood, known to promote bone and muscle growth as well as lipid accumulation. This study aimed to investigate the effects of formula milk with or without IGF1 supplementation (in the form of pure IGF1 or bovine colostrum) on growth and body composition in infant cynomolgus macaques during the first 6 months of life. Three groups of infants were nursery-reared and received formula milk with or without IGF1 or bovine colostrum supplementation for 4 months, and a fourth group consisting of breast-fed infants was included for comparison (n=6 for each group). Ranked-based analysis of covariance was used to detect differences between adjusted means for sex. No differences in weight, height, fat mass, and fat-free mass could be detected between groups. However, bone mineral density (BMD) was significantly different between groups at the end of formula feeding. Infants that received bovine colostrum supplementation displayed higher mean BMD than infants of all other groups, with no differences between the latter three groups. In conclusion, our results suggest that supplementation with bovine colostrum can enhance BMD in formula-fed infants, an effect that apparently does not depend on IGF1. Bovine colostrum supplementation could be beneficial for long-term bone health in infants with suboptimal bone growth.

A theoretical study on protonation of some halogen substituted pyridine derivatives.

The geometries of 12 multi-halogenated pyridine derivatives were optimized using theoretical methods. The Hartree-Fock (HF) method with the 6-31G(d) and B3LYP method with 6-31G(d) basis sets were found to be adequate in calculation of absolute acidity constants, pK(a) values. A perfect correlation between the computed and experimentally obtained acidity constants, pK(a) values, was observed.

Relapsing polychondritis--an Oriental case series.

INTRODUCTION: Relapsing polychondritis (RPC) has been described mainly in Caucasian populations. Reports from other ethnic groups are few. OBJECTIVES: To describe the clinical characteristics, management and outcome of RPC patients seen in an Oriental population in Singapore. METHODS: The case records of RPC patients treated in our department from 1989 to 2001 were reviewed. Only 12 fulfilled the McAdam-Michet-Damiani-Levine diagnostic criteria and these were studied. RESULTS: The female-to-male ratio in our series was 3:1. There were 10 ethnic Chinese and two Malay patients. The age of onset of symptoms ranges from three to 65 years, with a mean of 34 years. A diagnosis was made from two weeks to three years after onset, with a median of 4.5 months. There were 10 patients with pinna, nine articular, eight ocular, six laryngotracheal, five inner ear, four nasal and one cardiac involvement. Five presented with fever. None of them had cutaneous, renal or central nervous system involvement. Ten had raised ESR at presentation. One patient developed discoid lupus erythematosus two years later. All 12 patients received prednisolone with eight of them requiring additional immunosuppressants. Two patients had resistant disease failing to respond adequately to various immunosuppressants together with prednisolone. There was no mortality amongst the nine patients who had remained on follow-up at the time of this report. Five of the six patients with laryngotracheal involvement had tracheostomy and one of them had airway stenting as well. CONCLUSION: Our series suggests that although the clinical manifestations of RPC are similar in the Oriental and the Caucasian populations, Oriental patients may have less cutaneous, renal or nervous system involvement and more serious airway complications.

Tissue microangiography using a simplified barium sulphate cadaver injection technique.

This study investigated the application of soft tissue X-ray imaging as a method of studying vascular anatomy in injected cadaveric specimens. The arterial system of the anatomical region of interest was perfused with a barium sulphate-gelatin suspension. After curing, the tissues were removed by meticulous dissection and examined using the soft tissue X-ray imaging system. This technique of microangiography was able to demonstrate the entire arterial system of the perfused specimen. This simplified technique shows great potential in the study of vascular anatomy of flaps.

Identification and cloning of a novel heterogeneous nuclear ribonucleoprotein C-like protein that functions as a transcriptional activator of the hepatitis B virus enhancer II.

Liver specificity of hepatitis B virus (HBV) replication has been attributed to the action of its second enhancer (EII). We report here the characterization of EII and the subsequent isolation of a novel liver-specific DNA-binding protein which binds to and activates EII. The cDNA clone of the protein, designated E2BP, was isolated from a lambda gt11 expression library constructed from the hepatoma cell line HuH-6 which was screened with a binding site probe derived from EII. Sequence analysis of E2BP revealed 86.6% homology with a rat heterogeneous nuclear ribonucleoprotein C protein sequence, while conformational studies suggest a helix-loop-helix motif as a DNA-binding site. Cloned E2BP expressed in human fibroblasts by transient transfection displayed EII binding and activating characteristics similar to those of native E2BP in hepatocytes.

Detection of integrated hepatitis B virus DNA in hepatocellular carcinoma cell lines by nonradioactive in situ hybridization.

A sensitive and specific nonradioactive in situ hybridization method capable of detecting single-copy integrated hepatitis B virus (HBV) DNA sequences in hepatocellular carcinoma (HCC) cell lines was developed. In situ hybridization of biotinylated HBV (adr, adw) DNA probes with nine different human HCC cell lines were carried out in 96-well microtiter plates. Integration was detected in HCC cell lines HCCM, Hep3B, huH-1, huH-4, and PLC/PRF/5. Detection of single-copy HBV DNA sequences was also achieved in Hep3B and huH-4. HCC cell lines HepG2, HUH-6, HUH-7, Mahlavu, and the non-HCC control MCF-7, gave clear negative results. These results show a 100% correlation with those obtained by Southern blot hybridization assay. The results demonstrate that nonradioactive detection of single-copy integrated HBV DNA sequences in HCC cell lines is possible by the method described, which has potential application for viral genome analysis requiring in situ hybridization.