TSH is produced by the:

A positive niacin test is most characteristic of Mycobacterium:

A first-morning sputum specimen is received for acid-fast culture. The specimen is centrifuged, and the sediment is inoculated on two Lowenstein-Jensen slants that are incubated at 35C in 5%-10% CO2. After 1 week, the slants show abundant growth over the entire surface. Stains reveal gram-negative bacilli. To avoid this problem:

Which of the following inorganic substances are excreted in the urine in the largest amount?

Hepatitis C (nonenteric form of non-A, non-B hepatitis) differs from hepatitis A and hepatitis B because it:

A patient has a history of mild hemorrhagic episodes. Laboratory results include a prolonged prothrombin time and activated partial thromboplastin time. The abnormal prothrombin time was corrected by normal and adsorbed plasma, but not aged serum. Which of the following coagulation factors is deficient?

In a disk diffusion susceptibility test, which of the following can result if disks are placed on the inoculated media and left at room temperature for an hour before incubation?

In which of the following conditions would a NORMAL level of creatine kinase be found?

Following repeat exposure to an antigen, rapid antibody production to an elevated level that persists for a long period of time is called:

The most serious transfusion reactions are due to incompatibility in which of the following blood group systems?