Adolescent forced swim stress increases social anxiety-like behaviors and alters kappa opioid receptor function in the basolateral amygdala of male rats

Adolescence is a developmental period marked by robust neural alterations and heightened vulnerability to stress, a factor that is highly associated with increased risk for emotional processing deficits, such as anxiety. Stress-induced upregulation of the dynorphin/kappa opioid receptor (DYN/KOP) system is thought to, in part, underlie the negative affect associated with stress. The basolateral amygdala (BLA) is a key structure involved in anxiety, and neuromodulatory systems, such as the DYN/KOP system, can 1) regulate BLA neural activity in an age-dependent manner in stress-naïve animals and 2) underlie stress-induced anxiety in adults. However, the role of the DYN/KOP system in modulating stress-induced anxiety in adolescents is unknown. To test this, we examined the impact of an acute, 2-day forced swim stress (FSS - 10 min each day) on adolescent (~postnatal day (P) 35) and adult Sprague-Dawley rats (~P70), followed by behavioral, molecular and electrophysiological assessment 24 h following FSS. Adolescent males, but not adult males or females of either age, demonstrated social anxiety-like behavioral alterations indexed via significantly reduced social investigation and preference when tested 24 h following FSS. Conversely, adult males exhibited increased social preference. While there were no FSS-induced changes in expression of genes related to the DYN/KOP system in the BLA, these behavioral alterations were associated with alterations in BLA KOP function. Specifically, while GABA transmission in BLA pyramidal neurons from non-stressed adolescent males responded variably (potentiated, suppressed, or was unchanged) to the KOP agonist, U69593, U69593 significantly inhibited BLA GABA transmission in the majority of neurons from stressed adolescent males, consistent with the observed anxiogenic phenotype in stressed adolescent males. This is the first study to demonstrate stress-induced alterations in BLA KOP function that may contribute to stress-induced social anxiety in adolescent males. Importantly, these findings provide evidence for potential KOP-dependent mechanisms that may contribute to pathophysiological interactions with subsequent stress challenges.

Functional gene diversity of oolitic sands from Great Bahama Bank

Despite the importance of oolitic depositional systems as indicators of climate and reservoirs of inorganic C, little is known about the microbial functional diversity, structure, composition, and potential metabolic processes leading to precipitation of carbonates. To fill this gap, we assess the metabolic gene carriage and extracellular polymeric substance (EPS) development in microbial communities associated with oolitic carbonate sediments from the Bahamas Archipelago. Oolitic sediments ranging from high-energy 'active' to lower energy 'non-active' and 'microbially stabilized' environments were examined as they represent contrasting depositional settings, mostly influenced by tidal flows and wave-generated currents. Functional gene analysis, which employed a microarray-based gene technology, detected a total of 12,432 of 95,847 distinct gene probes, including a large number of metabolic processes previously linked to mineral precipitation. Among these, gene-encoding enzymes for denitrification, sulfate reduction, ammonification, and oxygenic/anoxygenic photosynthesis were abundant. In addition, a broad diversity of genes was related to organic carbon degradation, and N2 fixation implying these communities has metabolic plasticity that enables survival under oligotrophic conditions. Differences in functional genes were detected among the environments, with higher diversity associated with non-active and microbially stabilized environments in comparison with the active environment. EPS showed a gradient increase from active to microbially stabilized communities, and when combined with functional gene analysis, which revealed genes encoding EPS-degrading enzymes (chitinases, glucoamylase, amylases), supports a putative role of EPS-mediated microbial calcium carbonate precipitation. We propose that carbonate precipitation in marine oolitic biofilms is spatially and temporally controlled by a complex consortium of microbes with diverse physiologies, including photosynthesizers, heterotrophs, denitrifiers, sulfate reducers, and ammonifiers.

P4-01-14: Fulvestrant Regulates Epidermal Growth Factor (EGF) Ligands and Induces EGF Receptor Activation in MCF-7 Breast Cancer Cells

Selective Estrogen Receptor Modulators (SERMs) 4 Hydroxy Tamoxifen (4-HT) and fulvestrant (fulv) inhibit estrogen receptor a (ER) positive breast cancer growth. We have observed that treatment (24 to 48 hours) of fulv in MCF-7 cells induced a 190kDa tyrosine phosphorylated band, which was blocked by EGFR and HER-2 tyrosine kinase inhibitors erlotinib and lapatinib. Immunoprecipitation showed EGFR, HER-2, and HER-3 were all phosphorylated after fulv treatment. 4-HT and estradiol did not cause this phosphorylation. No changes in receptor level after fulv treatment were noted. Downstream MAPK signaling was also blocked by erlotinib and lapatinib. Fulv induced activation of EGFR was ER dependent, since fulv treatment in C4-12, an ER negative cell line derived from MCF-7 cells, did not induce EGFR activation. Co-treatment with estradiol and fulv prevented EGFR activation. To explore the possibility that fulv enhanced ligand expression, we collected conditioned media (CM) from MCF-7 cells after 48 hours of treatment. pEGFR was lost when CM was removed, but recurred within 30 minutes. Cycloheximide abolished the ability of fulv to activate EGFR suggesting autorcine production of EGFR ligands was induced by fulv. To detect specific EGFR ligands, we used qPCR to measure various EGFR ligand mRNA levels in MCF-7 and C4-12 cell at 1, 4, 24 and 48 hours after fulv treatment. TGF-α and HB-EGF mRNAs were upregulated over 48 hours, which correlated well with pEGFR activation. 4-HT did not affect mRNA levels of these ligands. In contrast, amphiregulin (AREG) mRNA levels were substantially reduced 48 hours after fulv treatment. A similar trend was seen for AREG mRNA levels in 4HT treated cells but to a much lesser extent. There was no change in any EGFR ligand mRNA levels in ER negative C4-12 cells. These qPCR data suggested differential regulation of EGFR ligands by fulv treatment contributed to EGFR family member activation and was dependent on ER expression. Upon fulv treatment, levels of ER were diminished with decreased detection of S167 and S118 ER phosphorylation sites. Monolayer cell growth analysis showed that while fulv treatment in SFM reduced MCF-7 cell numbers compared to control treatment, erlotinib plus fulv significantly reduced cell numbers below the level of cells maintained in fulv alone. In conclusion, we show that fulv, but not E2 or 4-HT, activates EGFR family members accompanied by upregulation of ligands. Since SERM resistance has been associated with EGFR family member activation, differential control of EGFR ligand gene expression by ER may contribute to the development of fulvestrant resistance in breast cancer.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-01-14.

Indicator microbes correlate with pathogenic bacteria, yeasts and helminthes in sand at a subtropical recreational beach site

AIMS

Research into the relationship between pathogens, faecal indicator microbes and environmental factors in beach sand has been limited, yet vital to the understanding of the microbial relationship between sand and the water column and to the improvement of criteria for better human health protection at beaches. The objectives of this study were to evaluate the presence and distribution of pathogens in various zones of beach sand (subtidal, intertidal and supratidal) and to assess their relationship with environmental parameters and indicator microbes at a non-point source subtropical marine beach.

METHODS AND RESULTS

In this exploratory study in subtropical Miami (Florida, USA), beach sand samples were collected and analysed over the course of 6 days for several pathogens, microbial source tracking markers and indicator microbes. An inverse correlation between moisture content and most indicator microbes was found. Significant associations were identified between some indicator microbes and pathogens (such as nematode larvae and yeasts in the genus Candida), which are from classes of microbes that are rarely evaluated in the context of recreational beach use.

CONCLUSIONS

Results indicate that indicator microbes may predict the presence of some of the pathogens, in particular helminthes, yeasts and the bacterial pathogen Staphylococcus aureus including methicillin-resistant forms. Indicator microbes may thus be useful for monitoring beach sand and water quality at non-point source beaches.

SIGNIFICANCE AND IMPACT OF THE STUDY

The presence of both indicator microbes and pathogens in beach sand provides one possible explanation for human health effects reported at non-point sources beaches.

Chronic ethanol and withdrawal effects on kainate receptor-mediated excitatory neurotransmission in the rat basolateral amygdala

Withdrawal (WD) anxiety is a significant factor contributing to continued alcohol abuse in alcoholics. This anxiety is extensive, long-lasting, and develops well after the obvious physical symptoms of acute WD. The neurobiological mechanisms underlying this prolonged WD-induced anxiety are not well understood. The basolateral amygdala (BLA) is a major emotional center in the brain and regulates the expression of anxiety. New evidence suggests that increased glutamatergic function in the BLA may contribute to WD-related anxiety following chronic ethanol exposure. Recent evidence also suggests that kainate-type ionotropic glutamate receptors are inhibited by intoxicating concentrations of acute ethanol. This acute sensitivity suggests potential (KA-R) contributions by these receptors to the increased glutamatergic function seen during chronic exposure. Therefore, we examined the effect of chronic intermittent ethanol (CIE) and WD on KA-R-mediated synaptic transmission in the BLA of Sprague-Dawley rats. Our study showed that CIE, but not WD, increased synaptic responses mediated by KA-Rs. Interestingly, both CIE and WD occluded KA-R-mediated synaptic plasticity. Finally, we found that BLA field excitatory postsynaptic potential responses were increased during CIE and WD via a mechanism that is independent of glutamate release from presynaptic terminals. Taken together, these data suggest that KA-Rs might contribute to postsynaptic increases in glutamatergic synaptic transmission during CIE and that the mechanisms responsible for the expression of KA-R-dependent synaptic plasticity might be engaged by chronic ethanol exposure and WD.

Identification of genotypically diverse Cryptococcus neoformans and Cryptococcus gattii isolates by Luminex xMAP technology

A Luminex suspension array, which had been developed for identification of Cryptococcus neoformans and Cryptococcus gattii isolates, was tested by genotyping a set of 58 mostly clinical isolates. All genotypes of C. neoformans and C. gattii were included. In addition, cerebrospinal fluid (CSF) obtained from patients with cryptococcal meningitis was used to investigate the feasibility of the technique for identification of the infecting strain. The suspension array correctly identified haploid isolates in all cases. Furthermore, hybrid isolates possessing two alleles of the Luminex probe region could be identified as hybrids. In CSF specimens, the genotype of the cryptococcal strains responsible for infection could be identified after optimization of the PCR conditions. However, further optimization of the DNA extraction protocol is needed to enhance the usability of the method in clinical practice.

Microcoding: the second step in DNA barcoding

After the process of DNA barcoding has become well advanced in a group of organisms, as it has in the economically important fungi, the question then arises as to whether shorter and literally more barcode-like DNA segments should be utilized to facilitate rapid identification and, where applicable, detection. Through appropriate software analysis of typical full-length barcodes (generally over 500 base pairs long), uniquely distinctive oligonucleotide 'microcodes' of less than 25 bp can be found that allow rapid identification of circa 100-200 species on various array-like platforms. Microarrays can in principle fulfill the function of microcode-based species identification but, because of their high cost and low level of reusability, they tend to be less cost-effective. Two alternative platforms in current use in fungal identification are reusable nylon-based macroarrays and the Luminex system of specific, colour-coded DNA detection beads analysed by means of a flow cytometer. When the most efficient means of rapid barcode-based species identification is sought, a choice can be made either for one of these methodologies or for basic high-throughput sequencing, depending on the strategic outlook of the investigator and on current costs. Arrays and functionally similar platforms may have a particular advantage when a biologically complex material such as soil or a human respiratory secretion sample is analysed to give a census of relevant species present.

Molecular sequence analyses of the intergenic spacer (IGS) associated with rDNA of the two varieties of the pathogenic yeast, Cryptococcus neoformans

The pathogen Crytococcus neoformans has been traditionally grouped in two varieties, C. neoforrmans var. neoformans (serotypes A, D and AD) and C. neoformans var. gattii (serotypes B and C). A recent taxonomic evaluation of C. neoformans var. neoformans described C. neoformans var. grubii as a new variety represented by serotype A isolates. Despite immunological, biochemical, ecological and molecular differences the three varieties are classified within one species. We examined the genetic variability of one hundred and five clinical and environmental isolates that included all varieties and serotypes. Sequence analysis of the intergenic spacer (IGS) associated with rDNA revealed significant differences in nucleotide composition between and within the varieties. Parsimony analysis showed five different genotypes representing distinct genetic lineages. Although there was a high degree of relatedness between serotype and genotype this relatedness was not exclusive as serotypes were not restricted to one particular genotypic group. Serotyping and sequence analyses indicate that C. neoformans var. grubii (serotype A) should not be recognized as a separate variety. Based on this study we propose to accept two separate species, C. neoformans (serotypes A, D and AD) and C. bacillisporus (serotypes B and C synonymous with C. neoformans var. gattii).

Molecular analyses of the IGS & ITS regions of rDNA of the psychrophilic yeasts in the genus Mrakia

Species of the genus Mrakia are currently classified as synonyms based on molecular sequence analyses of the large sub-unit ribosomal DNA (LrDNA). Physiological and protein electrophoretic studies, however, reveal possible species differences. To clarify this discrepancy, we undertook molecular sequence analyses of the internal transcribed spacer (ITS) and intergenic spacer (IGS) regions of rDNA from the four psychrophilic Mrakia species and the psychrophilic yeast, Cryptococcus curiosus. Identical ITS sequences were found between C. curiosus, M. nivalis and M. frigida. Although, M. stokesii and M. gelida displayed identical ITS and IGS sequences, their sequences differed from the other three species by 2.3% and 38%, respectively. The results suggest that M. stokesii is a synonym of M. gelida, whereas M. nivalis is a synonym of M. frigida. Sequence differences (1.9%) observed in the IGS region indicates that C. curiosus is a distinct strain of M. frigida.

Organic osmolytes in aerobic bacteria from mono lake, an alkaline, moderately hypersaline environment

The identity and concentrations of intracellular organic solutes were determined by nuclear magnetic resonance spectroscopy for two strains of aerobic, gram-negative bacteria isolated from Mono Lake, Calif., an alkaline, moderately hypersaline lake. Ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid) was the major endogenous solute in both organisms. Concentrations of ectoine varied with external NaCl levels in strain ML-D but not in strain ML-G, where the level was high but invariant from 1.5 to 3.0 M NaCl. Hydroxyectoine also occurred in strain ML-D, especially at elevated NaCl concentrations (2.5 and 3.0 M), but at levels lower than those of ectoine. Exogenous organic solutes that might occur in Mono Lake were examined for their effects on the de novo synthesis of ectoine. Dimethylsulfoniopropionate (DMSP) (0.1 or 1 mM) did not significantly lower ectoine levels in either isolate, and only strain ML-G showed any capacity for DMSP accumulation. With nitrogen limitation, however, DMSP (0.1 mM) substituted for ectoine in strain ML-G and became the main organic solute. Glycine betaine (GB) was more effective than DMSP in affecting ectoine levels, principally in strain ML-D. Strain ML-D accumulated GB to 50 or 67% of its organic solute pool at 2.5 M NaCl, at an external level of 0.1 or 1 mM GB, respectively. Strain ML-D also accumulated arsenobetaine. The methylated zwitterionic compounds, probably metabolic products of phytoplankton (DMSP and GB) or brine shrimps (arsenobetaine) in Mono Lake, may function as osmolytes for indigenous bacteria when present at high concentrations or under conditions of nitrogen limitation or salt stress.

Amniotic band syndrome: a nursing perspective

Amniotic band syndrome is a disease process that is unfamiliar to many neonatal nurses. It's presentation is variable in both type and severity, and pathophysiology and etiology still mystify those who have studied it in depth. Although better understood today, there remain many unanswered questions. A review of the current literature revealed an abundant supply of medically-based information and also a lack of resources focused on nursing-oriented information. This paper addresses the nursing implications of caring for an infant with amniotic band syndrome. A knowledgeable nurse will be able to assist in the diagnosis of amniotic band syndrome and have a better understanding of how to care for both the infant and his family. Both nursing and medical research needs to continue in this area to gain more knowledge about this complex disease process.

Heparin resistance after intraoperative platelet-rich plasma harvesting

Records of anticoagulation for cardiopulmonary bypass from 58 patients who underwent elective coronary artery revascularization were analyzed to determine whether the harvesting of autologous platelet-rich plasma produces heparin resistance. The effect of preoperative heparin therapy on anticoagulation for cardiopulmonary bypass after harvesting of platelet-rich plasma was also evaluated. Patients were grouped by presence of preoperative heparin therapy and type of blood component harvested before cardiopulmonary bypass, including platelet-rich plasma, autologous whole blood, both, or neither. The dose of heparin required to initiate and to maintain anticoagulation for cardiopulmonary bypass was determined for each patient, and the groups were compared by two-way analysis of variance. Significantly more heparin was required to maintain anticoagulation for cardiopulmonary bypass in the platelet-rich plasma group than in the groups receiving autologous whole blood or no blood products. More heparin was also required to initiate and to maintain anticoagulation for cardiopulmonary bypass after preoperative heparin therapy. These results reinforce the concept that anticoagulation during cardiopulmonary bypass must be carefully monitored, and increased vigilance may be warranted in patients after harvesting of platelet-rich plasma.