Deborah Doctor

The paraoxonase 1 variant I-F11 affords asymptomatic protection against the lethal effects of G-type chemical warfare nerve agents (CWNA). Here, we tested whether adeno-associated virus8 (AAV8) is able to deliver I-F11 for extended periods of time and at levels affording asymptomatic protection against 2-5LD50 doses of G-type CWNA in mice. I-F11 gene expression levels in mouse blood were assessed under the influence of three different promoters and found to be significantly higher with TBG compared to CMV and CASI. A single tail vein or intramuscular injection of AAV8-TBG-I-F11 resulted in robust production of the enzyme, which reached concentrations of up to 1 to 2 mg/ml in mouse blood for up to 6 months. Mice containing 0.75 mg/ml or higher concentrations of I-F11 in their blood were afforded asymptomatic protection against multiple 5LD50 exposures of GD, GF, GA, and GB, a total of 9 exposures over a seven-week period. We also conducted studies showing that I-F11 is most efficacio...

Chemical warfare nerve agents are organophosphorus chemical compounds that induce cholinergic crisis, leaving little or no time for medical intervention to prevent death. The current chemical treatment regimen may prevent death but does not prevent postexposure complications such as brain damage and permanent behavioral abnormalities. In the present study, we have demonstrated an adeno-associated virus 8 (AAV8)–mediated paraoxonase 1 variant IF-11 (PON1-IF11) gene therapy that offers asymptomatic prophylactic protection to mice against multiple lethal doses of G-type chemical warfare nerve agents, namely, tabun, sarin, cyclosarin, and soman, for up to 5 months in mice. A single injection of liver-specific adeno-associated viral particles loaded with PON1-IF11 gene resulted in expression and secretion of recombinant PON1-IF11 in milligram quantities, which has the catalytic power to break down G-type chemical warfare nerve agents into biologically inactive products in vitro and in vi...

Exogenously administered cholinesterases (ChEs) have been successfully used as a safe and efficacious prophylactic treatment to prevent poisoning by organophosphorus (OP) compounds in animal models. Of the ChEs evaluated so far, human serum butyrylcholinesterase (Hu BChE) is the most suitable candidate for human use. The potential application of Hu BChE as an OP detoxifying drug relies on its ability to

A rapid and sensitive assay for pyridinium oximes in plasma and tissue was developed. The method was suitable for the analysis of mono- and di-pyridinium oximes and utilizes ultrafiltration followed by cation-exchange high-performance liquid chromatography with UV detection. The assay was originally developed for the measurement of the oxime MMB-4 in plasma for which the lower limit of detection was 0.0005 pg and the limit of quantitation was 0.001 to 2.5 microg. The assay required as little as 50 microL of whole blood or 30 pL of tissue homogenate, and it was used for a pharmacokinetic study from a single intramuscular injection of MMB-4 (dichloride or dimethylsulfonate salt) in the guinea pig. Both salts were found to have similar pharmacokinetic properties in the plasma with a T1/2 of about 34 to 42 min and the area-under-the-curve values increased dose dependently. MMB-4 tissue concentrations were much lower than the plasma. The tissue levels peaked at 5-20 min depending on the tissue. A rank of concentration was diaphragm > heart > thigh muscle.

Huperzine A (Hup A) is under investigation as a treatment of Alzheimer's disease because of its properties of reversible and specific AChE inhibition. It has additional interesting pharmacological effects such as the protection of primary neuronal cells isolated from embryonic rat brains from glutamate-induced toxicity. We have isolated a new compound which has similar absorbance characteristics as Hup A from blood of rats administered Hup A. Monitoring the effluent from reversed-phase high-performance liquid chromatography (RP-HPLC) of blood collected 60 min after Hup A treatment at an absorbance of 308 nm (lambdamax for Hup A), yielded a peak height and area for this compound that was approximately 1.4-fold the initial Hup A peak. The compound was isolated from RP-HPLC fractions from blood and liver for analysis by mass spectrometry and nuclear magnetic resonance (NMR). The compound gave an (M+H)+ ion with m/z 259 in positive ion mode, yielding a molecular weight (MW) of 258. ...