No abstract

Exposure to the nerve agent soman is difficult to treat due to the rapid dealkylation of soman-acetylcholinesterase (AChE) conjugate known as aging. Oxime antidotes commonly used to reactivate organophosphate inhibited AChE are ineffective against soman, while the efficacy of the recommended nerve agent bioscavenger butyrylcholinesterase is limited by strictly stoichiometric scavenging. To overcome this limitation, we tested ex vivo, in human blood, and in vivo, in soman exposed mice, the capacity of aging-resistant human AChE mutant Y337A/F338A in combination with oxime HI-6 to act as a catalytic bioscavenger of soman. HI-6 was previously shown in vitro to efficiently reactivate this mutant upon soman, as well as VX, cyclosarin, sarin and paraoxon inhibition. We here demonstrate that ex vivo, in whole human blood, 1 μM soman was detoxified within 30 minutes when supplemented with 0.5 μM Y337A/F338A AChE and 100 μM HI-6. This combination was further tested in vivo. Catalytic scavenging of soman in mice improved the therapeutic outcome and resulted in the delayed onset of toxicity symptoms. Furthermore, in a preliminary in vitro screen we identified an even more efficacious oxime than HI-6, in a series of forty-two pyridinium aldoximes, and five imidazole 2-aldoxime N-propyl pyridinium derivatives. One of the later imidazole aldoximes, RS-170B, was a 2–3 –fold more effective reactivator of Y337A/F338A AChE than HI-6 due to the smaller imidazole ring, as indicated by computational molecular models, that affords a more productive angle of nucleophilic attack.

Chorioamnionitis is an intra-amniotic infection with serious maternal and neonatal complications. Clinical studies suggest antibiotic administration before delivery reduces the risk of complications compared to after delivery. Our center implemented a standardized intrapartum gentamicin computerized provider order entry and dosage form dispensing system intended to improve treatment initiation efficiency in hospitalized obstetric patients. The primary objective of this retrospective study was to determine if these system changes were associated with decreased time from gentamicin ordering to administration in patients with chorioamnionitis. A secondary objective was to compare clinical outcomes before and after system changes. Classification and regression tree (CART) analyses was applied to identify key predictors. Results demonstrated a trend towards reduced time to administration in the post-implementation group. Clinical outcomes were not altered. CART analysis revealed that post-implementation assignment and length of membrane rupture predicted shorter time to gentamicin initiation. This study suggests that the specific system changes we implemented were safe and improved efficiency, but additional changes are needed to have a clinically significant impact.