71.   T-cells are a major target of HIV after the viral infection begins causing symptoms of AIDS and the immune system is compromised.

72.   The challenge was to figure out what had caused their symptoms.

73.   The drugs are unpleasant to take, causing flulike symptoms, including fever, lethargy, malaise, and achiness.

74.   The mosquito-borne pathogen causes no symptoms in most people.

75.   The low-dose version causes troublesome symptoms such as breast tenderness.

76.   The Nipah virus, for example, appears to hide without causing disease symptoms in a species of fruit-eating bat.

77.   The parasites move through the bloodstream, where they can live for years without causing symptoms.

78.   The reduction of blood flow would be less likely to cause symptoms as quickly in a larger artery.

79.   The study is the first to document that the nonhormonal bone-building drug prevents fractures significant enough to cause symptoms.

80.   The tumors can cause symptoms like pain, weight loss and severe abdominal bloating that can make patients appear pregnant.