Repeated USMLE Questions Step 1- 373

Q- Amnestic syndrome due to thiamine deficiency is caused by lesions of which one of the following structures?

A- Cerebellum

B- Limbic system

C- Parietal lobe

D- Temporal lobe

B- Limbic system- Amnestic syndrome occurs due to lesions of the limbic system.

Q- Which of the following is NOT considered an indication for HIV testing?

A- Homosexuality

B- Patients with symptoms of AIDS

C- Recent positive test of a partner

D- Semen donor

A-Homosexuality- It is not considered an indication of testing unless it is associated with symptoms of AIDS.

Q- Which one of the following enzymes is extremely important in muscle energy metabolism through its role in purine nucleotide cycle?

A- Adenosine deaminase

B- Hypoxanthine-guanine phosphoribosyltransferase (HGPRT)

C- Myoadenylate deaminase

D- Myo-inositol monophosphatase

C- Myoadenylate deaminase- It catalyses the deamination of AMP to IMP which is important step in purine nucleotide metabolism.