The population etiologic fraction for a particular disease from Factor X alone is five times greater than that from Factor Y alone. If the relative risk associated with Factor X is 2, and with Factor Y is 20, which of the following statements is true?
A. The risk of developing the disease is greater in those exposed to Factor X only than in those exposed to Factor Y only.
B. Fewer persons are exposed to Factor Y than to Factor X.
C. The proportion of the disease in the population attributable to Factor Y is greater than that attributable to Factor X.
D. More persons are exposed to Factor Y than to Factor x.

Adouble-blinded trial for a new indication is conducted under an ind comparing two (2) marketed drugs, at twice the approved prescribed doses. on day 2, subject 603 had difficulty breathing. although it was life-threatening initially, subject 603 was treated and discharged directly from the emergency department after complete recovery. on day 5, subject 20 had a headache, which led to hospitalization and required blood pressure lowering medications. these episodes cannot be explained on the basis of the pharmacological property of either drug or the subjects' medical histories. the investigator would submit an sae report for: a. neither of the subjects b. subject 603 only c. subject 20 only d. both of the subjects

What is the function of reverse transcriptase in retroviruses? a) it uses viral rna as a template for dna synthesis.b) it converts host cell rna into viral dna.c) it translates viral rna into proteins.d) it uses viral rna as a template for making complementary rna strands.

A46-year-old man with a history of hypertension and hypercholesterolemia visits the physician for a routine followup. the patient's job involves a lot of travelling, and he admits to occasionally forgetting to take his medications with him when he travels. he complains of several episodes of chest pain in the past few months. the pain is sharp in nature, mainly over his lower chest and epigastrium, and tends to come on when walking. he believes these episodes are due to indigestion and has been taking antacids. there is a family history of heart disease, and his father died of a heart attack at age 48. on physical examination, his blood pressure is 150/80 mmhg and heart rate is 86/min. his lungs are clear to auscultation. cardiac auscultation reveals normal rate and rhythm, without rubs, gallops, or murmurs. there is no pedal oedema. he is sent for an exercise stress test. five minutes into the test, he develops st depression of 3mm in leads v1-v5. the st segment depression is greater than 0.12 seconds in duration and the stress test is stopped. which of the following is the most appropriate next step in management? - coronary angiography- holter monitor- no further tests are required- repeat stress test with thallium- upper gastrointestinal endoscopy