2) anaphylaxis. The Columbia Encyclopedia, Sixth Edition. 2001
...When an anaphylactic state exists, a second dose of the same protein (commonly an antibiotic such as penicillin, or certain insect venoms) will cause a violent allergic...

3) salt, chemical compound. The Columbia Encyclopedia, Sixth Edition. 2001
...Characteristics and Classification of SaltsThe most familiar salt is sodium chloride, the principal component of common table salt. Sodium chloride, NaCl, and water,...

4) histamine. The Columbia Encyclopedia, Sixth Edition. 2001
...Although found in many plant and animal tissues, histamine is specifically important in human physiology because it is one of the chemicals released from certain...