Benzylpenicillin of penicillin allergy. Use during pregnancy is generally safe. It is in the penicillin and β-lactam class of medications. Benzylpenicillin was discovered in 1929 by Alexander Fleming and came into commercial use in 1942. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. The wholesale cost in the developing world is about US$0.24–2.72 per day. In the United States a course of treatment costs $100–200. As an antibiotic, benzylpenicillin is noted to possess effectiveness mainly against Gram-positive organisms. Some Gram-negative organisms such as "Neisseria gonorrhoeae" and "Leptospira
Valentine Leeper woman", and as being at "the forefront of insightful biography". Valentine Leeper Valentine Alexa Leeper (14 February 1900 – 26 July 2001) was an Australian classicist, teacher, polemicist, and letter-writer of renown. Valentine Leeper was born on Valentine's Day 1900 in the Leeper Building of Trinity College at the University of Melbourne, daughter of Dr Alexander Leeper, first Warden of that college, and his second wife, Mary (née Moule). Her half-brothers, Reginald Leeper and Allen Leeper, both became prominent British diplomats. Her brother, Geoffrey Leeper, became the first professor of agricultural chemistry at the University of Melbourne. Valentine was educated