Sex differences after chronic stress in the expression of opioid-, stress- and neuroplasticity-related genes in the rat hippocampus.

Opioid peptides and their receptors re-organize within hippocampal neurons of female, but not male, rats following chronic immobilization stress (CIS) in a manner that promotes drug-related learning. This study was conducted to determine if there are also sex differences in gene expression in the hippocampus following CIS. Adult female and male rats were subjected to CIS (30 min/day) for 10 days. Twenty-four hours after the last stressor, the rats were euthanized, the brains were harvested and the medial (dentate gyrus/CA1) and lateral (CA2/CA3) dorsal hippocampus were isolated. Following total RNA isolation, cDNA was prepared for gene expression analysis using a RT2 Profiler PCR expression array. This custom designed qPCR expression array contained genes for opioid peptides and receptors, as well as genes involved in stress-responses and candidate genes involved in synaptic plasticity, including those upregulated following oxycodone self-administration in mice. Few sex differences are seen in hippocampal gene expression in control (unstressed) rats. In response to CIS, gene expression in the hippocampus was altered in males but not females. In males, opioid, stress, plasticity and kinase/signaling genes were all down-regulated following CIS, except for the gene that codes for corticotropin releasing hormone, which was upregulated. Changes in opioid gene expression following chronic stress were limited to the CA2 and CA3 regions (lateral sample). In conclusion, modest sex- and regional-differences are seen in expression of the opioid receptor genes, as well as genes involved in stress and plasticity responses in the hippocampus following CIS.

Differences in prevalence of community-associated MRSA and MSSA among U.S. and non-U.S. born populations in six New York Community Health Centers.

BACKGROUND: Staphylococcus aureus is the most common cause of Skin and Soft Tissue Infections (SSTIs) in the community in the United States of America. Community Health Centers (CHC) serve as primary care providers for thousands of immigrants in New York. METHODS: As part of a research collaborative, 6 New York City-area CHCs recruited patients with SSTIs. Characterization was performed in all S. aureus isolates from wounds and nasal swabs collected from patients. Statistical analysis examined the differences in wound and nasal cultures among immigrant compared to native-born patients. RESULTS: Wound and nasal specimens were recovered from 129 patients and tested for antibiotic susceptibility. 40 patients were immigrants from 15 different countries. Although not statistically significant, immigrants had lower rates of MRSA infections (n = 15) than did native-born participants, and immigrants showed significantly higher rates of MSSA wound cultures (n = 11) (OR = 3.5, 95% CI: 1.3, 9.7). CONCLUSIONS: In our study, immigrants were more likely to present with SSTIs caused by MSSA than US-born patients. Immigants also reported lower frequencies of antibiotic prescription or consumption in the months prior to SSTI infection. This suggests that antibiotic resistance may vary regionally and that immigrants presenting with SSTIs may benefit from a broader range of antibiotics.

Self administration of oxycodone alters synaptic plasticity gene expression in the hippocampus differentially in male adolescent and adult mice.

Abuse and addiction to prescription opioids such as oxycodone (a short-acting Mu opioid receptor (MOP-r) agonist) in adolescence is a pressing public health issue. We have previously shown differences in oxycodone self-administration behaviors between adolescent and adult C57BL/6J mice and expression of striatal neurotransmitter receptor genes, in areas involved in reward. In this study, we aimed to determine whether oxycodone self-administration differentially affects genes regulating synaptic plasticity in the hippocampus of adolescent compared to adult mice, since the hippocampus may be involved in learning aspects associated with chronic drug self administration. Hippocampus was isolated for mRNA analysis from mice that had self administered oxycodone (0.25 mg/kg/infusion) 2h/day for 14 consecutive days or from yoked saline controls. Gene expression was analyzed with real-time polymerase chain reaction (PCR) using a commercially available "synaptic plasticity" PCR array containing 84 genes. We found that adolescent and adult control mice significantly differed in the expression of several genes in the absence of oxycodone exposure, including those coding for mitogen-activated protein kinase, calcium/calmodulin-dependent protein kinase II gamma subunit, glutamate receptor, ionotropic AMPA2 and metabotropic 5. Chronic oxycodone self administration increased proviral integration site 1 (Pim1) and thymoma viral proto-oncogene 1 mRNA levels compared to controls in both age groups. Both Pim1 and cadherin 2 mRNAs showed a significant combined effect of Drug Condition and Age × Drug Condition. Furthermore, the mRNA levels of both cadherin 2 and cAMP response element modulators showed an experiment-wise significant difference between oxycodone and saline control in adult but not in adolescent mice. Overall, this study demonstrates for the first time that chronic oxycodone self-administration differentially alters synaptic plasticity gene expression in the hippocampus of adolescent and adult mice.