Doses Of Sulfur Mustard Research Articles

A 7‐Day Mouse Model to Assess Protection from Sulfur Mustard (SM) Skin Injury

The mouse ear vesicant model (MEVM) is a screening tool used to identify protective compounds against acute sulfur mustard (SM)‐induced skin injury. It provides endpoints of edema and histopathology 24 h following a topical SM exposure to assess protection against inflammation and tissue damage. To further evaluate successful compounds, the MEVM was modified for use as a 7‐day model. Dose response studies were conducted with SM to select an optimal challenge dose for the new model. Due to severity of SM‐induced tissue damage by Day 7, edema and histopathology were determined unreliable endpoints. Therefore, a modified Draize scoring system (no damage to extensive necrosis) was incorporated as an endpoint to evaluate tissue damage out to Day 7. To aid in optimal SM dose selection, retro synthetic capsaicin (RSCAP), a protective compound in the MEVM, was evaluated as a treatment 15 min before exposure to 0.06, 0.08, and 0.16 mg SM. The RSCAP compound provided similar significant protection at Day 7 against ...

Activation of Poly [ADP-Ribose] Polymerase in Endothelial Cells and Keratinocytes: Role in anin VitroModel of Sulfur Mustard-Mediated Vesication

Although endothelial cells and keratinocytes appear to be the primary cellular targets of sulfur mustard (SM), the role of the nuclear enzyme poly (ADP-ribose) polymerase (PARP) in SM-induced vesication has not been clearly defined. PARP is thought to play a crucial role in DNA repair mechanisms following exposure to alkylating agents like SM. Using a combination of fluorescence microscopy and biochemical assays, we tested the hypothesis that SM causes activation of PARP in endothelial cells and keratinocytes with subsequent loss of nicotinamide adenine dinucleotide (NAD) and depletion of adenosine triphosphate (ATP) levels. To determine if PARP activation accounts for SM-induced vesication, keratinocyte adherence and permeability of endothelial monolayers were measured asin vitrocorrelates of vesication. As early as 2 to 3 h after exposure to SM concentrations as low as 250 μM, dramatic changes were induced in keratinocyte morphology and microfilament architecture. Exposure to 500 μM SM induced a fourfold increase in PARP activity in endothelial cells, and a two- to threefold increase in keratinocytes. SM induced a dose-related loss of NAD+in both endothelial cells and keratinocytes. ATP levels fell to ∼50% of control levels in response to SM concentrations ≥500 μM. SM concentrations ≥250 μM significantly reduced keratinocyte adherence as early as 3 h after exposure. Endothelial monolayer permeability increased substantially with concentrations of SM >250 μM. These observations support the hypothesis that the pathogenic events necessary for SM-induced vesication (i.e., capillary leak and loss of keratinocyte adherence) at higher vesicating doses of SM (≥500 μM) may depend on NAD loss with PARP activation and subsequent ATP-dependent effects on microfilament architecture. Vesication developing as a result of exposure to lower concentrations of SM presumably occurs by mechanisms that do not depend on loss of cellular ATP (e.g., apoptosis and direct SM-mediated damage to integrins and the basement membrane).

Effect of sulfur mustard on murine lymphocytes

The effect on spleen cells of a single in vivo treatment with sulfur mustard was analyzed in mice 1 week after intoxication. A marked decrease in the number of total spleen cells was observed in mice receiving high doses of sulfur mustard. Flow cytometric analysis indicated that B-lymphocytes were relatively more affected than T-lymphocytes by this toxic compound. However, the function of remaining B-cells, measured by thymidine incorporation and immunoglobulin secretion in the presence of lipopolysaccharide, was not significantly impaired. In addition, sulfur mustard did not depress T-lymphocyte function since their proliferation in response to concanavalin A or to an anti-CD3 antibody was not affected by the treatment. These results suggest that whereas some observations reported in patients can be found in a murine model, additional in vitro studies with human lymphocytes could more adequately provide further information on sulfur-mustard-induced alterations of the immune system.

Microblister Formation in Vesicant-Exposed Pig Skin

AbstractSix pigs were cutaneously exposed for 1 hr to high doses of sulfur mustard (HD) by both direct droplet contact and indirect vapor. Tissue was harvested for microscopic examination after 72 hr. Three other pigs were cutaneously exposed to HD and lewisite (L) by droplet streak application. Histologically, all test subjects exhibited microvesicle formations of varying intensities. Vapor exposures produced diffuse lesions of lesser severity than lesions induced by direct droplet or droplet streak exposures, which affected smaller areas but to a greater depth. Blistering is a pathologic change commonly observed in human skin, but rarely reported in experimental animals. The appearance of microvesicles in HD- and L-exposed pig skin supports the use of this animal as a model for future studies involving HD or L injury.