October 2013 JPGN
1 - Mutations in which four nuclear genes are associated with mitochondrial DNA depletion and rapidly progressive liver failure?
2 - Which of the following are not described presentations of mitochondrial DNA depletion?
A   - Intestinal pseudobstruction
B   - Acute liver failure following Valproic acid therapy.
C   - Intractable seizures.
D   - Apparent viral induced liver failure
E   - Migraine Headaches
F   - All of the above are described
3 - Concerning hepatotoxic medications and genetic testing the authors conclude that current evidence supports:
A   - Isoniazid should never be prescribed to individuals with known mutations in DGUOK
B   - DGUOK, MPV17 and POLG sequencing should always be performed prior to starting valproic acid
C   - Caution should be exercised in prescribing hepatotoxic drugs to individuals carrying, or who are suspected of carrying mutations in DGUOK, POLG & MPV17
D   - Fructose should be used to treat liver injury in individuals with mitochondrial DNA depletion
4 - Which of the following statements is not true?
A   - Liver disease severe enough to require liver transplantation causes mitochondrial DNA depletion
B   - In animal models, bile acid accumulation causes mitochondrial dysfunction
C   - Being a carrier for a mutation in an mtDNA depletion gene is more common in individuals with viral, unexplained or drug induced liver disease than the general population
D   - Mitochondrial copy number is lower in individuals with viral, unexplained or drug induced liver disease than liver donors
5 - All of the following stimulate gastrin secretion except:
A   - Calcium
B   - Vagal stimulation
C   - Long-chain fatty acids
D   - Gastric distention
E   - Peptides
6 - The difference between serum gastrin levels in the treatment naïve infants versus the treatment experienced infants (previously exposed to H2-receptor antagonists, PPIs or both) can best be described by the following statement:
A   - There is little difference in any of the age sub-groups analyzed (1-<4, 4-<8m, 8-<12 months)
B   - The greatest difference is seen in infants between 1-4 months of age
C   - The difference increases with increasing age
D   - The difference is statistically significant in all three age subgroups analyzed
E   - The greatest difference is in the oldest age subgroup
7 - Which of the following statements accurately describes serum gastrin levels reported in this study in infants less than one year of age?
A   - Serum gastrin levels are generally elevated above adult normal ranges for the entire first year of life especially in infants between birth and 8 months of age
B   - Serum gastrin levels are reduced at birth and rise to adult levels by 4 months of age
C   - Serum gastrin levels are unresponsive to acid-suppressive medications (proton-pump inhibitors, H2-receptor antagonists) in the first 4 months of life, but rise in response after 4 months of age
D   - Hypergastrinemia is more commonly seen in infants exposed to proton pump inhibitors than H2-receptor antagonists
E   - In infants, exposure to acid-suppressive medications must be long-term (>3 months) in order to result in enterochromaffin cell like (ECL) hyperplasia and hypergastrinemia
8 - The most likely potential confounder for interpretation of serum gastrin levels inherent in the design of this study is:
A   - Lack of knowledge about the H. Pylori infection status in every patient.
B   - Lack of a uniform protein intake between breast fed and bottle fed infants
C   - Inability to impose a uniform fasting period of at least 8 hours prior to sampling the blood for serum gastrin levels
D   - Control of the doses of PPIs or H2RAs in infants with prior exposure to these medications
E   - Variability in the type of serum gastrin radioimmunoassay employed