Journal club of the week: Sulfur mustard (SM)

 Speaker: PhDs Dr. Fazlullah
Date: In the 06th June 2016
Topic: Sulfur mustard

In the 06th June 2016 journal club meeting, the PhDs Dr. Fazlullah introduced all participants to different types of the mustard compounds. Sulfur mustard (SM), commonly known as mustard gas, is a cytotoxic and vesicant chemical warfare agent with the ability to form large blisters on the exposed skin and in the lungs. Related chemical compounds with similar chemical structure and similar properties form a class of compounds known collectively as SM or mustard agents. Pure SM is colorless, viscous liquids at room temperature. When used in impure form, such as warfare agents, it is usually yellow-brown in color and has an odor resembling mustard plants, garlic or horseradish. The mechanism of cellular toxicity such as the compound readily eliminates a chloride ion by intramolecular nucleophilic substitution to form a cyclic sulfonium ion was discussed. This very reactive intermediate tends to cause permanent alkylation of the guanine nucleotide in DNA strands, which prevents cellular division and generally leads directly to apoptosis, or if cell death is not immediate, the damaged DNA may lead to the development of cancer. Oxidative stress would be another pathology involved in SM toxicity. SM is not very soluble in water but is very soluble in fat, contributing to its rapid absorption into the skin. The speaker briefly discussed the chronic effects of mustard gas on various systems which leave for long lasting. SM has extremely powerful vesicant effects on its victims. In addition, it is strongly mutagenic and carcinogenic, due to its alkylating properties. It is also lipophilic. Because people exposed to SM rarely suffer immediate symptoms, and mustard-contaminated areas may appear completely normal, victims can unknowingly receive high dosages. Within 24 hours of exposure to SM, victims experience intense itching and skin irritation, which gradually turns into large blisters filled with yellow fluid wherever the mustard agent contacted the skin. These are chemical burns and are very debilitating. SM vapor easily penetrates clothing fabrics such as wool or cotton, so it is not only the exposed skin of victims that gets burned. If the victim's eyes were exposed then they become sore, starting with conjunctivitis, after which the eyelids swell, resulting in temporary blindness. In rare cases of extreme ocular exposure to SM vapors, corneal ulceration, and anterior chamber scarring, and neovascularization can occur. At the end, all participants appreciated the speaker, asked questions and the speaker answered in a good way. Prof Mohammad Abdollahi summarized the whole presentation and gave suggestions to be aware of mustard gas exposure.