Cammidge Reaction

Cammidge Reaction (Cammidge), proposed by the author for the diagnosis of pancreatic diseases. The reaction is apparently based on the presence in urine during pancreatic disease of poly- and disaccharides (dextrin?). Technique of the reaction: 10 cm³ of filtered urine freed from protein and sugar is mixed with 1 cm³ of strong HCl and hydrolyzed by boiling for 10 min. After cooling, the liquid is diluted with an equal volume of water, 4 g of lead carbonate is added to 10 cm³ of the mixture, and after some time, it is filtered. To the filtrate, 2 g of sodium acetate, 0.075 g of phenylhydrazine hydrochloride are added, and it is boiled for 3-4 min. Upon cooling, in case of a positive reaction, an osazone precipitate falls out in the form of rosettes of yellow crystals soluble in 30% sulfuric acid. In a new work, K. determines the amount of reducing substances by the Folin and Wu method before and after hydrolysis. The difference between the two determinations serves as a measure of the content of poly- and disaccharides in urine. According to Cammidge, the reaction gives a positive result in pancreatitis and tumors of the pancreas. Urine precipitated with half its volume of a saturated solution of corrosive sublimate, according to the author, gives a positive result only in new growths. The Cammidge reaction has not to this day received a satisfactory explanation either in regard to its chemical mechanism or in regard to the factors determining its positive or negative result. Most authors who have checked the value of the Cammidge reaction deny any diagnostic significance.