Role of NAD(P)H Oxidase in Superoxide Generation and Endothelial Dysfunction in Goto-Kakizaki (GK) Rats as a Model of Nonobese NIDDM

Background: Cardiovascular disease is the leading cause of mortality in diabetics, and it has a complex etiology that operates on several levels. Endothelial dysfunction and increased generation of reactive oxygen species are believed to be an underlying cause of vascular dysfunction and coronary artery disease in diabetes. This impairment is likely the result of decreased bioavailability of nitric oxide (NO) within the vasculature. However, it is unclear whether hyperglycemia per se stimulates NADPH oxidase-derived superoxide generation in vascular tissue. Methods and Results: This study focused on whether NADPH oxidase-derived superoxide is elevated in vasculature tissue evoking endothelial/smooth muscle dysfunction in the hyperglycemic (16964 mg%) Goto-Kakizaki (GK) rat. By dihydroethidine fluorescence staining, we determined that aorta superoxide levels were significantly elevated in 9 month-old GK compared with age matched Wistar (GK; 19566%, Wistar; 10063.5%). Consistent with these findings, 10 26 mol/L acetylcholine-induced relaxation of the carotid artery was significantly reduced in GK rats compared with age matched Wistar (GK; 4167%, Wistar; 10065%) and measurements in the aorta showed a similar trend (p =.08). In contrast, relaxation to the NO donor SNAP was unaltered in GK compared to Wistar. Endothelial dysfunction was reversed by lowering of superoxide with apocynin, a specific Nox inhibitor. Conclusions: The major findings from this study are that chronic hyperglycemia induces significant vascular dysfunction i

Pre-Clinical Evaluation of a Novel Nanoemulsion-Based Hepatitis B Mucosal Vaccine

Hepatitis B virus infection remains an important global health concern despite the availability of safe and effective prophylactic vaccines. Limitations to these vaccines include requirement for refrigeration and three immunizations thereby restricting use in the developing world. A new nasal hepatitis B vaccine composed of recombinant hepatitis B surface antigen (HBsAg) in a novel nanoemulsion (NE) adjuvant (HBsAg-NE) could be effective with fewer administrations.Physical characterization indicated that HBsAg-NE consists of uniform lipid droplets (349+/-17 nm) associated with HBsAg through electrostatic and hydrophobic interactions. Immunogenicity of HBsAg-NE vaccine was evaluated in mice, rats and guinea pigs. Animals immunized intranasally developed robust and sustained systemic IgG, mucosal IgA and strong antigen-specific cellular immune responses. Serum IgG reached > or = 10(6) titers and was comparable to intramuscular vaccination with alum-adjuvanted vaccine (HBsAg-Alu). Normalization showed that HBsAg-NE vaccination correlates with a protective immunity equivalent or greater than 1000 IU/ml. Th1 polarized immune response was indicated by IFN-gamma and TNF-alpha cytokine production and elevated levels of IgG(2) subclass of HBsAg-specific antibodies. The vaccine retains full immunogenicity for a year at 4 degrees C, 6 months at 25 degrees C and 6 weeks at 40 degrees C. Comprehensive pre-clinical toxicology evaluation demonstrated that HBsAg-NE vaccine is safe and well tolerated in multiple animal models.Our results suggest that needle-free nasal immunization with HBsAg-NE could be a safe and effective hepatitis B vaccine, or provide an alternative booster administration for the parenteral hepatitis B vaccines. This vaccine induces a Th1 associated cellular immunity and also may provide therapeutic benefit to patients with chronic hepatitis B infection who lack cellular immune responses to adequately control viral replication. Long-term stability of this vaccine formulation at elevated temperatures suggests a direct advantage in the field, since potential excursions from cold chain maintenance could be tolerated without a loss in therapeutic efficacy

Lipidomes of brain from rats acutely intoxicated with diisopropylfluorophosphate identifies potential therapeutic targets.

Organophosphates (OPs), a class of phosphorus-containing chemicals that act by disrupting cholinergic transmission, include both toxic and fast-acting chemical warfare agents as well as less toxic but more easily accessible OP pesticides. The classical atropine/2-PAM antidote fails to protect against long-term symptoms following acute intoxication with OPs at levels that trigger status epilepticus. Acute OP intoxication also causes a robust neuroinflammatory response, which is implicated in the pathogenesis of long-term effects. In this study, we characterized the profiles of lipid mediators, important players in neuroinflammation, in the rat model of acute DFP intoxication. The profiles of lipid mediators were monitored in three different regions of the brain (cortex, hippocampus, and cerebellum) at 0, 1, 3, 7, 14, and 28 days post-exposure. The distribution pattern of lipid mediators was distinct in the three brain regions. In the cerebellum, the profile is dominated by LOX metabolites, while the lipid mediator profiles in cortex and hippocampus are dominated by COX metabolites followed by LOX and CYP 450 metabolites. Following acute DFP intoxication, most of the pro-inflammatory lipid mediators (e.g., PGD2 and PGE2) increased rapidly from day 1, while the concentrations of some anti-inflammatory lipid mediators (e.g. 14,15 EpETrE) decreased after DFP intoxication but recovered by day 14 post-exposure. The lipidomics results suggest two potential treatment targets: blocking the formation of prostaglandins by inhibiting COX and stabilizing the anti-inflammatory lipid mediators containing epoxides by inhibiting the enzyme soluble epoxide hydrolase (sEH)