Business-to-business - "B2B" - refers to commerce between two businesses rather than to commerce between a business and an individual consumer. Transactions at the wholesale level are usually business-to-business while those at the retail level are most often business-to-consumer (B2C).

41 What is the difference between transudate and exudate?

42 I wish to ask about Meigs' syndrome. I know that it is an association of pleural effusion, ascites and benign ovarian tumours or fibromas. Is the effusion transudate or exudate?

43 I have read that patients with cystic fibrosis should not meet each other socially. Why is this?

44 I have a young patient with bilateral hilar lymphadenopathy but no other manifestations of sarcoidosis. How can I make a diagnosis?

45 We have read in your book that continuous oxygen therapy at home reduces mortality in chronic obstructive pulmonary disease (COPD). I am concerned that my patient might develop acute respiratory failure.

46 I have a patient with asthma who is on long-term inhaled corticosteroids. She is very concerned about long-term steroid therapy. Could I replace the steroids with a long-acting beta2 agonist?

47 What is the role of leukotriene-modifying agents in asthma?

48 Is it true that the Mantoux test is no longer used?

49 Is there a screening test that is useful for the diagnosis of lung cancer?

50 For how long should treatment be continued for cervical lymphadenopathy and abdominal tuberculosis? What role, if any, do steroids play in the treatment of these conditions?