A Culture Collection of 50 Neisseria gonorrhoeae Isolates.

A culture collection of 50 Neisseria gonorrhoeae isolates is available from the CDC & FDA Antibiotic Resistance Isolate Bank. Associated data include antibiotic susceptibility information for azithromycin, cefixime, cefpodoxime, ceftriaxone, tetracycline, ciprofloxacin, penicillin, and spectinomycin and linked whole-genome sequences.

Maternal high-fat diet alters anxiety behavior and glucocorticoid signaling in adolescent offspring.

Maternal obesity and overconsumption of saturated fats during pregnancy have profound effects on offspring health, ranging from metabolic to behavioral disorders in later life. The influence of high-fat diet (HFD) exposure on the development of brain regions implicated in anxiety behavior is not well understood. We previously found that maternal HFD exposure is associated with an increase in anxiety behavior and alterations in the expression of several genes involved in inflammation via the glucocorticoid signaling pathway in adult rat offspring. During adolescence, the maturation of feedback systems mediating corticosteroid sensitivity is incomplete, and therefore distinct from adulthood. In this study, we examined the influence of maternal HFD on several measures of anxiety behavior and gene expression in adolescent offspring. We examined the expression of corticosteroid receptors and related inflammatory processes, as corticosteroid receptors are known to regulate circulating corticosterone levels during basal and stress conditions in addition to influencing inflammatory processes in the hippocampus and amygdala. We found that adolescent animals perinatally exposed to HFD generally showed decreased anxiety behavior accompanied by a selective alteration in the expression of the glucocorticoid receptor and several downstream inflammatory genes in the hippocampus and amygdala. These data suggest that adolescence constitutes an additional period when the effects of developmental programming may modify mental health trajectories.

Exercise and environment as an intervention for neonatal alcohol effects on hippocampal adult neurogenesis and learning.

Neonatal alcohol exposure impairs cognition and learning in adulthood and permanently damages the hippocampus. Wheel running (WR) improves hippocampus-associated learning and memory and increases the genesis and survival of newly generated neurons in the hippocampal dentate gyrus. WR significantly increases proliferation of newly generated dentate granule cells in alcohol-exposed (AE) and control rats on Postnatal Day (PD) 42 but only control rats show an increased number of surviving cells thirty days after WR (Helfer et al., 2009b). The present studies examined whether proliferation-promoting WR followed by survival-enhancing environmental complexity (EC) during adolescence could increase survival of new neurons in AE rats. On PD 4-9, pups were intubated with alcohol in a binge-like manner (5.25g/kg/day, AE), were sham-intubated (SI), or were reared normally (suckle control, SC). On PD 30 animals were assigned to WR (PD 30-42) followed by EC (PD 42-72; WR/EC) or were socially housed (SH/SH) for the duration of the experiment. All animals were injected with 200mg/kg bromodeoxyuridine (BrdU) on PD 41. In Experiment 1, survival of newly generated cells was significantly enhanced in the AE-WR/EC group in comparison with AE-SH/SH group. Experiment 2A examined trace eyeblink conditioning. In the SH/SH condition, AE impaired trace eyeblink conditioning relative to SI and SC controls. In the WR/EC condition, AE rats performed as well as controls. In Experiment 2B, the same intervention was examined using the context preexposure facilitation effect (CPFE); a hippocampus-dependent variant of contextual fear conditioning. Again, the WR/EC intervention reversed the deficit in conditioned fear to the context that was evident in the SH/SH condition. Post-weaning environmental manipulations promote cell survival and reverse learning deficits in rats that were exposed to alcohol during development. These manipulations may provide a basis for developing interventions that ameliorate learning impairments associated with human fetal alcohol spectrum disorders.

Perinatal high fat diet alters glucocorticoid signaling and anxiety behavior in adulthood.

Maternal obesity carries significant health risks for offspring that manifest later in life, including metabolic syndrome, cardiovascular disease and affective disorders. Programming of the hypothalamic-pituitary-adrenal (HPA) axis during development mediates both metabolic homeostasis and the response to psychosocial stress in offspring. A diet high in fat alters maternal systemic corticosterone levels, but effects in offspring on limbic brain areas regulating the HPA axis and anxiety behavior are poorly understood. In addition to their role in the response to psychosocial stress, corticosteroid receptors form part of the glucocorticoid signaling pathway comprising downstream inflammatory processes. Increased systemic inflammation is a hallmark of high-fat diet exposure, though altered expression of these genes in limbic brain areas has not been examined. We studied the influence of high-fat diet exposure during pre-weaning development in rats on gene expression in the amygdala and hippocampus by quantitative real-time polymerase chain reaction (PCR), anxiety behavior in the Open field, elevated plus maze and light-dark transition tasks, and corticosterone levels in response to stress by radioimmunoassay. As adults, offspring exposed to perinatal high-fat diet show increased expression of corticosterone receptors in the amygdala and altered pro-inflammatory and anti-inflammatory expression in the hippocampus and amygdala in genes known to be regulated by the glucocorticoid receptor. These changes were associated with increased anxiety behavior, decreased basal corticosterone levels and a slower return to baseline levels following a stress challenge. The data indicate that the dietary environment during development programs glucocorticoid signaling pathways in limbic areas relevant for the regulation of HPA function and anxiety behavior.

Effects of exercise and environmental complexity on deficits in trace and contextual fear conditioning produced by neonatal alcohol exposure in rats.

In rodents, voluntary exercise and environmental complexity increases hippocampal neurogenesis and reverses spatial learning and long-term potentiation deficits in animals prenatally exposed to alcohol. The present experiment extended these findings to neonatal alcohol exposure and to delay, trace, and contextual fear conditioning. Rats were administered either 5.25 g/kg/day alcohol via gastric intubation or received sham-intubations (SI) between Postnatal Day (PD) 4 and 9 followed by either free access to a running wheel on PD 30-41 and housing in a complex environment on PD 42-72 (wheel-running plus environmental complexity; WREC) or conventional social housing (SHSH) from PD 30 to 72. Adult rats (PD 80 ± 5) received 5 trials/day of a 10-s flashing-light conditioned stimulus (CS) paired with .8 mA footshock either immediately (delay conditioning) or after a 10-s trace interval (trace conditioning) for 2 days. Neonatal alcohol exposure impaired context and trace conditioning, but not short-delay conditioning. The WREC intervention did not reverse these deficits, despite increasing context-related freezing in ethanol-exposed and SI animals.

Neonatal alcohol exposure disrupts hippocampal neurogenesis and contextual fear conditioning in adult rats.

Developmental alcohol exposure can permanently alter brain structures and produce functional impairments in many aspects of behavior, including learning and memory. This study evaluates the effect of neonatal alcohol exposure on adult neurogenesis in the dentate gyrus of the hippocampus and the implications of such exposure for hippocampus-dependent contextual fear conditioning. Alcohol-exposed rats (AE) received 5.25g/kg/day of alcohol on postnatal days (PD) 4-9 (third trimester in humans), in a binge-like manner. Two control groups were included: sham-intubated (SI) and suckle-control (SC). Animals were housed in social cages (3/cage) after weaning. On PD80, animals were injected with 200mg/kg BrdU. Half of the animals were sacrificed 2h later. The remainder were sacrificed on PD114 to evaluate cell survival; separate AE, SI, and SC rats not injected with BrdU were tested for the context preexposure facilitation effect (CPFE; ~PD117). There was no difference in the number of BrdU+ cells in AE, SI and SC groups on PD80. On PD114, cell survival was significantly decreased in AE rats, demonstrating that developmental alcohol exposure damages new cells' ability to incorporate into the network and survive. Behaviorally tested SC and SI groups preexposed to the training context 24h prior to receiving a 1.5mA 2s footshock froze significantly more during the context test than their counterparts preexposed to an alternate context. AE rats failed to show the CPFE. The current study shows the detrimental, long-lasting effects of developmental alcohol exposure on hippocampal adult neurogenesis and contextual fear conditioning.

Analysis of xylem formation in pine by cDNA sequencing.

Secondary xylem (wood) formation is likely to involve some genes expressed rarely or not at all in herbaceous plants. Moreover, environmental and developmental stimuli influence secondary xylem differentiation, producing morphological and chemical changes in wood. To increase our understanding of xylem formation, and to provide material for comparative analysis of gymnosperm and angiosperm sequences, ESTs were obtained from immature xylem of loblolly pine (Pinus taeda L.). A total of 1,097 single-pass sequences were obtained from 5' ends of cDNAs made from gravistimulated tissue from bent trees. Cluster analysis detected 107 groups of similar sequences, ranging in size from 2 to 20 sequences. A total of 361 sequences fell into these groups, whereas 736 sequences were unique. About 55% of the pine EST sequences show similarity to previously described sequences in public databases. About 10% of the recognized genes encode factors involved in cell wall formation. Sequences similar to cell wall proteins, most known lignin biosynthetic enzymes, and several enzymes of carbohydrate metabolism were found. A number of putative regulatory proteins also are represented. Expression patterns of several of these genes were studied in various tissues and organs of pine. Sequencing novel genes expressed during xylem formation will provide a powerful means of identifying mechanisms controlling this important differentiation pathway.

Molecular cloning and sequence analysis of the penton base genes of type II avian adenoviruses.

We describe here the identification of the penton base gene of hemorrhagic enteritis virus (HEV), a type II avian adenovirus, in a 2477-base pair (bp)-EcoRI fragment of the viral DNA by sequence analysis. Identification is based on an extensive amino acid homology between the HEV-open reading frame and the penton base of a fowl adenovirus (FAV-10) and various human adenoviruses. The 1344 bp-penton base gene of HEV encodes a 448-amino acid polypeptide of molecular weight of 50,843 Da. The nucleotide sequences of penton base genes of HEV and marble spleen disease virus (MSDV) are identical. The HEV penton base lacks the RGD motif, present in most human adenoviruses (Ad2, Ad3, Ad4, and Ad 12) suggesting that HEV may not use alpha v integrins to gain entry into host cells. Further sequence analysis revealed the presence of a Leu-Asp-Val (LDV) motif in the HEV penton base amino acid sequence similar to most of the human adenoviruses. LDV motif on the fibronectin has been shown to interact with the alpha 4 beta 1 integrins on cells, which includes lymphocytes and monocytes. The presence of LDV motif in the penton base of HEV implicates the involvement of alpha 4 beta 1 integrins in the viral internalization into host cells.

Quantitation of human cytomegalovirus glycoprotein H gene in cells using competitive PCR and a rapid fluorescence-based detection system.

A technique is described for quantitation of the human cytomegalovirus (HCMV) glycoprotein H (gH) gene in cells using a quantitative-competitive polymerase chain reaction (QC-PCR). Two recombinant DNA molecules, differing in size due to a 92-bp deletion within the HCMV gH sequence, were used in co-amplification studies to construct a standard curve from which the copy number of the gH gene present in clinical samples could be interpolated. The use of primers labeled with a fluorescent dye allowed direct detection of the amplified products by measuring the amount of fluorescence emitted by each specific PCR fragment with an automated DNA sequencer coupled to a software program. This system was validated subsequently using bronchoalveolar lavage cells obtained from immunocompromised patients and found to be highly sensitive and reproducible over a range of 5-50,000 HCMV gH copies. This rapid procedure could easily be applied to study the pathogenesis of HCMV infection, identify the patients at high risk of developing HCMV disease, and monitor the effects of antiviral therapy at the molecular level.

Isolation of replication-competent molecular clones of visna virus.

Visna virus is the prototypic member of a subfamily of retroviruses responsible for slow infections of animals and humans. As a part of our investigation of the functions of viral gene products in virus replication, we have isolated three infectious molecular clones and determined the complete nucleotide sequences of two of the clones. We have also characterized the progeny of the biologically cloned viral stocks and of the infectious clones and document considerable heterogeneity in plaque size and antigenic phenotype of the former that is reduced to near homogeneity in the progeny of the infectious clones. It thus should now be possible to trace the emergence of antigenic variants of visna virus as well as ascribe defined functions to structural and regulatory genes of the virus in determining neurovirulence and the slow tempo of infection.