Skin decontamination efficacy of potassium ketoxime on rabbits exposed to sulfur mustard.

CONTEXT: The chemical weapon sulfur mustard (SM) is a blister agent, and currently, there is no effective antidote. OBJECTIVE: To evaluate the decontamination efficacy of potassium ketoxime against SM and preliminarily elucidate its decontamination mechanism. MATERIALS AND METHODS: Potassium ketoxime reacted with SM, and SM residues were tested at different time intervals by T-135 colorimetry after the reaction. Rabbit skin was topically exposed to 2 mg/cm(2) SM, treated with potassium ketoxime 1 min later, and observed after 6, 12, and 24 h. Gas chromatography-mass spectroscopy was employed to screen and identify the main products of potassium ketoxime decontamination of SM. RESULTS: Potassium ketoxime had a great effect against SM contamination. With a mass ratio of decontaminant: SM of 50:1, decontamination rates against SM were 87.5% after 30 s, 95.9% after 1 min, and 99.0% after 5 min. Fifteen minutes after exposure to SM, the untreated group showed clear erythema lesions, whereas the experimental group showed no clear erythema lesions within 6 h. After 12 and 24 h, the areas of damaged skin in the experimental group were 0.038 and 0.125 cm(2), respectively, compared with 2.21 and 2.65 cm(2) in the control group. Histopathological analysis revealed that treatment with potassium ketoxime also reduced inflammation-induced damage. CONCLUSION: The results of this study indicate that potassium ketoxime reacted rapidly and completely with SM, and thus, it was found to be a suitable and effective skin decontaminant against SM. The decontamination reaction mechanism is mainly related to nucleophilic substitution.

Spinal cord injury in rats treated using bone marrow mesenchymal stem-cell transplantation.

The aim of this study was to observe the effects of bone marrow mesenchymal stem-cell transplantation (BMSCs) in repairing acute spinal cord damage in rats and to examine the potential beneficial effects. 192 Wistar rats were randomized into 8 groups. Spinal cord injury was created. Behavior and limb functions were scored. Repairing effects of BMSCs transplantation was evaluated and compared. In vitro 4',6-diamidino-2-phenylindole (DAPI)-tagged BMSCs were observed, and whether they migrated to the area of spinal cord injury after intravenous tail injection was investigated. The expression of neuron-specific protein (NSE) on BMSCs was examined. Fifteen days after transplantation, the BMSCs-treated groups scored significantly higher in limb function tests than the untreated group. Pathological sections of the bone marrow after operation showed significant recovery in treated groups in comparison to the control group. After transplantation, small amounts of fluorescent-tagged BMSCs can be found in the blood vessels in the area of spinal cord injury, and fluorescent-tagged BMSCs were diffused in extravascular tissues, whereas the DAPI-tagged BMSCs could not be detected,and BrdU/NSE double-labeled cells were found in the injured marrow. BMSCs improve behavioral responses and can repair spinal cord injuries by migrating to the injured area, where they can differentiate into neurons.