41.   The immune system fights infection by identifying tissues foreign to the body and sending out antibodies to destroy them.

42.   Their chemical assaults weaken the invaders to help the immune system fight the infection.

43.   This pattern suggests, the scientists say, that the drugs fought chlamydia infections and protected some men from heart attacks.

44.   To fight infections, some scientists hope to design or find molecules that bind to the bacterial sensors, blocking out the signaling molecules.

45.   Those cells carry oxygen to organs, fight infection and help with clotting.

46.   Though few natural tonics have been tested as rigorously as drugs, many have been used for centuries to fight infection, boost immunity and restore lost vigor.

47.   Vitamin A helps fight infection.

48.   When blood vessels in that area are injured, there is no delivery system for antibiotics to fight infection.

49.   When the body fights infection, immune cells gather at the infection site, causing swelling.

50.   While antibiotics can fight infections in the devices, replacement appears to result in higher survival rates, the study said.