1. Concerning cell death by apoptosis and necrosis, which of the following statement(s) is/are true [1] ?

I. Neither apoptosis nor necrosis require ATPII. In apoptosis, DNA breakdown is comprised of specific size fragments (multiples of 185 base pairs), whereas random sized DNA fragments are found in necrotic cell deathIII. Apoptotic cell death stimulates strong humor but not cellular immune responsesIV. During early and mid-phase apoptosis, the plasma membrane is intact and blebbed, whereas in necrosis, the plasma membrane is lysed and cell contents are strewn out
V. Both necrosis and apoptosis are most often caused by ischemia
A. I, II, and III are correct concerning cell death by apoptosis and necrosis
B. I and III are correct concerning cell death by apoptosis and necrosis
C. II and IV are correct concerning cell death by apoptosis and necrosis
D. V alone is correct concerning cell death by apoptosis and necrosis
E. All of the above statements are correct concerning cell death by apoptosis and necrosis

2. Select the correct answer concerning the entry of human immunodeficiency virus (HIV) into cells [2]:

I. Fusion inhibitors block entry of HIV into cells by blocking HIV gp120 binding to cellsII. Both CD4 and a coreceptor such as CCR5 or CXCR4 are required for HIV entry into cellsIII. HIV gp41 mediates the final steps of fusion of the HIV envelope with the cell membraneIV. Resistance to HIV fusion inhibitors by mutation of gp120 has not arisen
V. Naturally occuring mutations in chemokine receptor CCR5 have no effect on entry of HIV into cells
A. I, II, and III are correct concerning HIV entry into cells
B. I and III are correct concerning HIV entry into cells
C. II and IV are correct concerning HIV entry into cells
D. V alone is correct concerning HIV entry into cells
E. All of the above statements are correct concerning HIV entry into cells

3. Estrogen replacement therapy (ERT) is no longer recommended for general treatment and prophylaxis of post-menopausal women. Select the correct statement concerning the mechanisms of action of ERT [3]:

I. ERT increases levels of serum triglyceridesII. ERT increases levels of total cholesterolIII. ERT increases levels of HDL cholesterolIV. ERT stimulates osteoblast activity in bone
V. ERT increases levels of C-reactive protein (CRP), a marker of systemic inflammation
A. I, II, and III are correct
B. I and III are correct
C. II and IV are correct
D. V alone is correct
E. All of the above statements are correct

4. In several types of leukemia, the abelson tyrosine kinase is fused to another gene called bcr forming a mutant tyrosine kinase called bcr-abl. Select the correct statement concerning this mechanism of leukemogenesis [4]:

I. Bcr-Abl proteins alone cannot transform normal cells to neoplastic cellsII. About 60% of chronic myelogenous leukemia (CML) cases express bcr-abl fusion proteinsIII. Imatinib (Gleevec®) is a specific inhibitor bcr-abl tyrosine kinase activity with no activity on normal abl or other growth-factor tyrosine kinase receptorsIV. A minority of cells with bcr-abl gene fusions are positive for the Philadelphia t(9;22) chromosome
V. The bcr-abl tyrosine kinase is constitutively active and blocks apoptotic cell death
A. I, II, and III are correct
B. I and III are correct
C. II and IV are correct
D. V alone is correct
E. None of the above statements is correct

5. Select the correct answer concerning atherosclerotic plaques and thrombosis [5]:

I. Plaque rupture is the most frequent cause of coronary thrombosisII. Young plaques have high levels of tissue factor (TF) which is highly thrombogenic III. Mature plaques are stable, but can increase in size and lead to angina and claudicationIV. Plaques with large, eccentric lipid pools and foam cells are most likely to rupture
V. Plaques with low levels of inflammatory cells tend to be more stable than those with high levels of inflammatory cells
A. I, II, and III are correct
B. I and III are correct
C. II and IV are correct
D. V alone is correct
E. All of the above statements are correct

6. Select the correct statement concerning the relationship between insulin and metabolic effects in patients with type 2 diabetes mellitus (DM2) [6]:
I. Insulin levels are typically within the normal range in most patients with DM2II. Dysfunction of glucose transporters such as GLUT-4 are found in many cases of DM2III. Insulin signalling through its receptor is typically normal in patients with DM2IV. Insulin resistance contributes to endothelial dysfunction and reduced nitric oxide production
V. Pharmacologic elevation of insulin levels in DM2 patients does not affect their lipid levels
A. I, II, and III are correct
B. I and III are correct
C. II and IV are correct
D. V alone is correct
E. All of the above statements are correct

Answers

1. C
2. A
3. E
4. D
5. E
6. C