Clinical effects of oleoresin capsicum (pepper spray) on the human cornea and conjunctiva.

OBJECTIVE: To evaluate the effects of oleoresin capsicum (OC) on the human cornea and conjunctiva and to test the effectiveness of topical anesthetics for relief of pain. DESIGN: Prospective, randomized clinical trial. METHODS: Forty-seven subjects were examined before and at 10 minutes and 1 hour after exposure to pepper spray during a training exercise. Eleven subjects were reexamined at 1 week after exposure. A short, subjective questionnaire was given asking subjects to rate their pain, blurring of vision, and tearing. After exposure, subjects were randomly given a placebo, a topical nonsteroidal antiinflammatory agent, or a topical anesthetic. MAIN OUTCOME MEASURES: Visual acuity and corneal sensitivity with a Cochet-Bonnet aesthesiometer (scale of 1-6 cm) was measured and the eyes were examined with a portable slit lamp using fluorescein. Symptoms of pain, blurring of vision, and tearing were recorded in a ranking of 0 to 10. RESULTS: Visual acuity was unaffected by exposure to pepper spray. Corneal sensitivity was reduced from a pretest mean of 5.7 cm to a posttest mean of 0.6 cm 10 minutes after exposure. At 1 hour, the mean corneal sensitivity had recovered to 2.9 cm. Twenty-one percent of eyes had evidence of punctate epithelial erosions, but no corneal abrasions were found. All subjects reported significant pain, blurring of vision, and tearing at 10 minutes that was much improved by 1 hour. Topical flurbiprofen 0.03% improved symptoms in two of 11 subjects, whereas topical proparacaine hydrochloride 0.5% improved symptoms in 16 of 29 eyes. At 1 week after exposure, corneal sensation returned to baseline, and no corneal abnormalities were noted. CONCLUSIONS: The predominant symptom after exposure to OC was pain. Topical flurbiprofen was not helpful in reducing symptoms of exposure, whereas topical proparacaine was effective in relieving pain in most subjects. Corneal sensitivity was dramatically reduced at 10 minutes after exposure and was improved after 1 hour. At 1 week, corneal sensation had returned to normal, as had slit-lamp appearance on all subjects examined.

Effects of Clostridium perfringens recombinant and crude phospholipase C and theta-toxin on rabbit hemodynamic parameters.

Clostridium perfringens exotoxins have been implicated as major virulence factors responsible for shock and organ failure in gas gangrene, yet the mechanism(s) by which they mediate cardiovascular dysfunction remain enigmatic. Recombinant (r) phospholipase C (PLC), r theta-toxin, culture supernatant (crude toxin), or 0.9% NaCl was infused intravenously into awake rabbits. Cardiac index (CI), mean arterial pressure (MAP), heart rate (HR), central venous pressure (CVP), arterial blood gases, and hematocrit were measured 1 h before and for 3 h after toxin infusion. Crude toxin and rPLC decreased CI, MAP, and HR and increased CVP; mortality was 87.5% and 83%, respectively. r theta-toxin did not decrease CI or MAP and mortality was 25%. Further, crude toxin and rPLC but not r theta-toxin inhibited cardiac contractility (dF/dt) in isolated rabbit atrial muscles. These results suggest that PLC-induced myocardial dysfunction contributes to shock in C. perfringens infection.

Purification of recombinant Shiga-like toxin type I A1 fragment from Escherichia coli.

Shiga-like toxin I A1 (Slt-IA1) is a RNA N-glycosidase which depurinates a specific adenosine of 28 S eukaryotic rRNA thus inhibiting protein synthesis and ultimately leading to cell death. We have overexpressed this protein in Escherichia coli using a high copy number plasmid and purified the enzyme to homogeneity using a three-step process. Slt-IA1 is released from the periplasm of cells using polymyxin B sulfate, precipitated with ammonium sulfate, and adsorbed to a Matrex Gel Green A dye-ligand agarose column. The enzyme is eluted from the Green A agarose as a single peak with 0.32 M NaCl. Slt-IA1 was purified approximately 1979-fold and routinely gave yields greater than 100%. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed a single band with an apparent molecular weight of 28,000. An isoelectric point of 5.1 was determined using analytical isoelectric focusing gels. In an in vitro protein synthesis inhibition assay, 0.02 pM of purified Slt-IA1 inhibited protein synthesis by 50%.