GI Final Review Flashcards
What factor raises the mortality risk with acute hepatitis E infection?
Third trimester pregnancy
HEV transmitted via contaminated food/water, blood, MTC
It is found that a patient has a sessile adenocarcinoma in the cecum. Molecular analysis of tumor demonstrates microsatellite instability. Immunostanding would likely review an absence of:
A. DNA mismatch repair protein.
B. Regulator of cell cycle.
C. Receptor tyrosine kinase
D. Small GTP binding proteins.
E. Transcriptional regulator.
A. DNA mismatch repair protein.
Colon cancer due to microsatellite instability = HNPCC/Lynch Syndrome (autosomal DOM)
Laparoscopic exploration of a patient reveals a smooth liver with normal morphologic features, but a grossly black appearance. What deficiency caused this?
MRP2 - mediates ATP-dependent transport of organic anions across the membrane of hepatocytes, as well as exports conjugated bilirubin into bile —> pigment not secreted from the hepatocyte is stored in the lysosome and causes black color
DX = Dubin Johnson syndrome: autosomal recessive disorder caused by mutation in ABCC2 Gene, which encodes glycoprotein called multi drug resistant protein 2 (MRP2)
74-year-old patient presents with acute onset of RUQ pain that is severe and constant. No past surgical history or travel. 102 fever. Scleral icterus is noted. Significant tenderness in the RUQ to both percussion and palpation. Ultrasound shows dilation of the common bile duct. Diagnosis?
A. Acute, viral hepatitis.
B. Acute cholecystitis.
C. Primary biliary cholangitis.
D. Acute cholangitis.
E. Acute pancreatitis.
D. Acute cholangitis.
A.k.a. ascending cholangitis - life-threatening condition caused by an ascending bacterial infection of the biliary tree
Classic presentation = fever + RUQ pain + jaundice
Which of the following is a cause of bilirubin (pigment) stones?
A. Oral contraceptive pills
B. Chronic hemolysis
C. High cholesterol diet.
D. Biliary tract infection
E. Dyslipidemia.
B. Chronic hemolysis
A/B/E others are associated with cholesterol stones
Biliary tract infections cause brown stones (not black)
Which of the following is consistent of biopsy of a patient with Zollinger Ellison syndrome?
A. Neutrophilic infiltration.
B. Parietal gland, hyperplasia.
C. Atrophic gastritis
D. MALToma
E. G cell hyperplasia.
B. Parietal gland hyperplasia - due to increase in gastrin secretion
41-year-old woman presents with debilitating fatigue and pruritus worsening over the past six months. Labs show normal liver function tests, except for markedly elevated alkaline phosphatase, an abnormal GGTP, and elevated cholesterol. Additional testing would likely demonstrate an increase in:
A. Anticardiolipin antibodies
B. Anti smooth muscle antibodies.
C. P – ANCA titers
D. Anti-mitochondrial antibodies.
E. Alpha-fetoprotein.
D. Anti-mitochondrial antibodies.
Dx = primary biliary cholangitis
Fatigue + itching are primary complaints
In which of the following is consistent with VIPoma?
A. Low gastric pH (<2)
B. Hypocalcemia
C. Enhanced glycogenolysis.
D. Hypokalemia.
E. Hypoglycemia.
D. Hypokalemia.
VIP is a potent stimulator of cAMP production and inhibitor of gastric acid secretion, promotes vasodilation/glycogenolysis/lipolysis/bone resorption
Secondary effects include huge secretion of water and electrolytes from the G.I. epithelial cells, hypokalemia, facial flushing, decreased gastric acidity, elevated blood glucose, and hypercalcemia
Mutation in which of the following is most likely to cause pancreatic cancer?
A. Small GTP binding protein.
B. Receptor, tyrosine kinase.
C. Serine threonine kinase
D. DNA mismatch repair gene
E. Cell – cell adhesion molecule
A. Small GTP binding protein.
Most frequently mutated is KRAS —> constitutive activation of ras, a small GTP binding protein that activates MAPK and PI3K/AKT pathways
other mutations include SMAD4 and p53
What is the most sensitive and specific indirect test of pancreatic function?
Fecal elastase - decreased when there is pancreatic insufficiency
57 year old patient with 15 year history of DM2. Presents with nausea, bloating, and early satiety. evaluation reveals delayed gastric emptying. What can be given as an appropriate therapeutic strategy for this patient to increase smooth muscle contractility and peristalsis?
Acetylcholine
MOA natalizumab
Monoclonal antibody that targets alpha4 integrin receptors on endothelial cells lining blood vessels
Decreases inflammation by blocking leukocytes migration
MOA lubiprostone
Chloride channel activator, leading to water and chloride secretion in to the stool and softer stool consistency
Helps relieve constipation
19 year old patient visits physician because his eyes look yellow in the morning. He feels well and is active in sports. No PMH. Minimal scleral icterus, normal heart sounds, no JVD, no hepatomegaly or splenomegaly. Lab analysis demonstrates total bilirubin of 3, and direct fraction of 0.1. Hepatitis B surface antigen is negative. Diagnosis?
Gilbert syndrome - elevated unconjugated bilirubin with no other symptoms
Onset occurs later in life (not at birth)
A rise in serum direct bilirubin would be expected in:
A. Physiological jaundice
B. Gilbert syndrome.
C. Crigler Najjar syndrome.
D. Dubin Johnson syndrome.
E. Hemolytic, anemia.
D. Dubin Johnson syndrome - decreased activity of MRP2 (transporter that exports conjugated bilirubin)
All others have reduced or total deficiency in the bilirubin UDP-glucoronyl transferase activity, which is important for conjugation of bilirubin to become direct bilirubin
Elevated conjugated bilirubin + near normal unconjugated bilirubin + absence of fecal stercobilin in a jaundiced patient =
A. Cholestasis.
B. Hemolytic, anemia.
C. Absence of bilirubin, UDP-glucoronyl transferase
D. Gilbert syndrome.
A. Cholestasis.
Absence of fecal urobilin indicates an obstruction of the biliary tract by gallstones, leading to cholestasis
A patient with a defect in the urea cycle can still temporarily detoxify ammonia through…
Amidation of glutamate to yield glutamine
High blood methionine concentration = deficiency in what enzyme?
Cystathionine b-synthase