One of the main causes of painful scrotal swelling is testicular torsion. This is an injury or an event that causes a testicle in the scrotal sac to twist and cut off blood circulation. This very painful injury could cause tissue death to the scrotum in a matter of hours. Medical conditions and diseases can also cause the scrotum to swell.
As said, credit and debit cards (cartes bancaires or cartes bleus) are widely used in France. This is also practical as automatic payments are common in France for things like train/metro tickets, parking, motorway tolls, etc.
The CAC 40 is similar to the Dow Jones Industrial Average in that it is the most commonly used index that represents the overall level and direction of the market in France. At the time of writing (Aug 2005), the CAC 40 included such companies as Renault, Michelin, L'Oreal and Vivendi Universal.