Vesicants and nerve agents in chemical warfare. Decontamination and treatment strategies for a changed world.

Vesicants and nerve agents have been used in chemical warfare for ages. They remain a threat in today's altered political climate because they are relatively simple to produce, transport, and deploy. Vesicants, such as mustard and lewisite, can affect the skin, eyes, respiratory system, and gastrointestinal system. They leave affected persons at risk for long-term effects. Nerve agents, such as tabun, sarin, soman, and VX, hyperstimulate the muscarinic and nicotinic receptors of the nervous system. Physicians need to familiarize themselves with the clinical findings of such exposures and the decontamination and treatment strategies necessary to minimize injuries and deaths.

Binding of 125I-succinylated concanavalin A to bovine spermatozoa.

This study characterizes interactions of 125I-succinylated concanavalin A (125I-sucConA) with plasma membranes of intact bovine spermatozoa. Maximum binding was achieved by 30 min at 24 degrees C. Reversibility of binding was established by displacement of bound ligand with nonradioactive sucConA. Seventy-five percent of the bound sucConA was removed as a single kinetics class. When alpha-methylmannoside was used as a competitive ligand, 90% of the sucConA was removed. Saturability of binding sites, however, was not achieved over the concentration range of 125I-sucConA examined (0.13 micrograms/ml to 77 micrograms/ml). Binding kinetics of this system was complex and linear Scatchard analysis was not appropriate. The degree of 125I-sucConA binding to spermatozoa was influenced (P less than 0.01) by different iodination batches of 125I-sucConA. Complications due to iodination of ligand and the complex nature of its interaction with the membrane preclude the use of 125I-sucConA for a quantitative study of sperm membrane features.

Peripheral toxicity of hemicholinium-3 in mice.

1 The site (i.e. peripheral or central) of the toxicity produced by hemicholinium-3 in mice was investigated. 2 Hemicholinium-3 was measured fluorometrically and acetylcholine was determined by gas chromatography after intraventricular or intraperitoneal administration of hemicholinium-3. 3 Hemicholinium-3 was not detected in the brain nor were acetylcholine levels decreased in the brain after systemic administration. 4 The dose-response curve following intraventricular administration demonstrated that hemicholinium-3 was not as lethal after central administration as it was after peripheral administration. 5 Approximately 24% of a 75 microgram intraventricular dose of hemicholinium-3 was found in the periphery at death. 6 These results suggest that hemicholinium-3 manifests its toxicity primarily in the periphery.

Readability and its application to poison prevention.

To improve communication with the general public, poison prevention materials must be written in a language suited to the population to be reached. The information should be nontechnical, concise and easily understood. Sentence length of written material should be short and the vocabulary kept simple. Recall can be significantly improved by organizing statements and labeling categories (12). The readability level must be kept low enough for the general public to read, comprehend and remember the material. This generally means writing no higher than the seventh or eighth-grade level. By using readability formulas to evaluate written poison prevention educational materials and simplifying the reading level, writers can improve comprehension of the information.

In situ recording of rat heart contractility devoid of respiratory artifacts.

A device was constructed for obtaining the cardiac force of contraction in the rat in situ. The devices was constructed from heat-resistant glass tubing that was opened to form a concave channel. The channel was notched and cup-shaped at one end. The apparatus was positioned around the heart to isolate it from lung or diaphragmatic tissue movement. The procedure was rapid, simple, inexpensive and free of respiratory artifacts. The method was an improvement over the more common in vitro recording techniques, since the heart had an intact nerve and blood supply. The method allowed quantitation of changes in the force of contraction, blood pressure and heart rate following the administration of acetylcholine, epinephrine, potassium chloride and barium chloride.