Biological agents history

Other reports have linked the use of chemicals to leukopenia, a lowered leukocyte count, in the low-normal range for laboratory workers exposed to routine amounts of toxic chemicals (402). Presumably this lowered leukocyte count may indicate that the worker is more likely to develop adverse health effects from exposure to other toxins or biological agents. Also, a history of asthma may predispose an individual to heightened chemical sensitivity (392). 

Hydrazinopyridazines such as hydralazine have a venerable history as anti hypertensive agents. It is of note that this biological activity is maintained in the face of major modifications in the heterocyclic nucleus. The key intermediate keto ester in principle can be obtained by alkylation of the anion of pi peri done 44 with ethyl bromo-acetate. The cyclic acylhydrazone formed on reaction with hydrazine (46) is then oxidized to give the aromatized compound 47. The hydroxyl group is then transformed to chloro by treatment with phosphorus oxychloride (48). Displacement of halogen with hydrazine leads to the formation of endralazine (49). ... 

Based on the history of terrorist attacks, which have mostly involved hijacking and bombing of aircraft, current threat-detection measures have concentrated on detecting weapons or explosives. In the future, terrorist attacks could also involve the use of toxic chemicals, chemical and biological warfare agents, or even radiological and nuclear materials.1 2... 

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