Treatment of Perianal and Anal Condylomata Acuminata: A New Operative Technique

rivative to a safe level. Nevertheless, it cannot be certain that the defence would never break down (Goldstein & Brown 1977). This possibility is now being investigated. To make my point concrete, I can mention that in a recent experiment in which acyclohexane solution of cholesterol (13.2 mg in 4 ml) was left in contact with air at about 20°C for 48 hours, enough hydroperoxide was formed to lower the interfacial tension by 48~0" The surface exposed to the air had a diameter of 1.7 ern. The estimation ofchange in the IT was made by a drop volume method in which the cyclohexane solution was passed through a glass tip into an aqueous phase of acid potassium phosphate. I am grateful to Professor H L Kornberg FRS for facilities provided, and to Dr J C Metcalfe, Dr G A Smith, Dr P K Tubbs and Professor A N Worden for helpful discussions. Yours truly