GI and Endo

Question 1

impairment of which defense mechanism against giardia

Answer 1

CD4+ helper cells and IgA protease. IgA protease inhibits the giardia’s ability to adhere to mucosal membrane

Question 2

blind pouch connected to the ileum –> as pancreatic acini. What is it?

Answer 2

Meckel diverticulum/ Ectopy: microscopically and functional normal cells found in abnormal location due to embryonic maldevelopment

Question 3

critically ill patients presenting with right upper quadrant abdominal pain, nausea, recurrent fever. Diagnosis?

Answer 3

inflamed and enlarged gallbladder due to an acalculous cholecystitis (NO gallstones)

Question 4

impingement of the splenic artery will affect which artery the most?

Answer 4

short gastric –> left gastroepiploic has an anastamosis with right gastroepiploic

Question 5

Girl has T1D and was hyperglycemia due to missing insulin shots. which enzyme increases production of gluconeogenic precursors in her situation

Answer 5

glycerol kinase: TH –> glycerol + FA –> (glycerol kinase) G3P–> DHAP

Question 6

what do you give to a patient in hypoglycemia

Answer 6

intramuscular glucagon

Question 7

18 month old with gradual regression of developmental milestones, enlarged liver/spleen, diminished DTR, cherry red spot. Diagnosis and accumulation of what substrate

Answer 7

Niemann Pick disease: sphingomyelinase deficiency.

Question 8

infant with otitis media and many bronchiolitis. oral candidiasis, low gamma globulin level and absent thymic shadow. Diagnosis?

Answer 8

SCID: very low or absent CD3 T cells and hypogammaglobulinemia

Question 9

women with increased abdominal fat and loss of adipose tissue from extremities and face. which medication would cause this?

Answer 9

HAART therapy

Question 10

31 yo man with myalgias, anorexia, and skin rash. he consumed a lot of raw egg whites for he past several months. What vitamin is deficient, and which biochemical conversion is it involved in?

Answer 10

Biotin (B7) is important for carboxylase enzymes (Pyruvate to OAA). Remember that egg whites have high levels of biotin binding avidin

Question 11

4 month old boy with upward eye deviation, bilateral arma nd leg shaking, fair skinned, musty body odor. Essential AA?

Answer 11

Tyrosine. Pt has PKU deficient in phenylalanine hydroxylase, that converts phenylalanine into tyrosine.

Question 12

What does increased estrogen and progesterone due to thyroid hormone levels?

Answer 12

Increase total T4. estrogen increases the production of TBG levels, causing reduction of free T4 and T3 levels. Pt will restore free levels by increasing thyroid hormone production. once free levels are restored, total T4 and T3 levels are leveled but do not cause increase in TSH

Question 13

Histology description of Hashimoto’s thyroiditis

Answer 13

Mononuclear infiltrate consisting of lymphocytes and germinal centers. Follicles are surrounded by hurthle cells

Question 14

Decrease in LPL causes what condition?

Answer 14

familial chylomicronemia syndrome due to LPL deficiency. Usually manifests as acute pancreatitis, lipemia retinalis, and eruptive xanthomas.

Question 15

50yo women with new onset T2DM, acanthosis nigracans, increase glucose and HbA1c of 8. Whats the disease process?

Answer 15

Insulin resistance will increase free fatty acid levels by impairng insulin dependent glucose uptake and increasing hepatic gluconeogenesis.

Question 16

Low surface expression of which receptor prevents cell interaction with T lymphocytes upon antigen exposure?

Answer 16

MHC Class II –> remember this is only displayed y antigen presenting cells

Question 17

62yo man with severe colicky upper abdominal vomiting with right upper quadrant ab tenderness. enzymes responsible for black stones in gall bladder?

Answer 17

Beta glucuronidase. black stones are due to chronic hemolysis and increased enterohepatic cyling of bilirubin –> increased unconjugated vili–> calcium bilirubin precipitation

Question 18

polyp characteristics that has the greatest risk for malignant transformation

Answer 18

2cm villous adenomatous polyp

Question 19

Cause of duodenal ulcers beyond the duodenal bulb?

Answer 19

ZES. H pylori infection are most proximal duodenal ulcers

Question 20

43yo travel history to south america. Spotty hepatocyte necrosis with inflammatory cell infiltration via biopsy. Dx?

Answer 20

Acute hepatitis due to hep A. Pt presents with fever, malaise, anorexia, NV, right upper quadrant abdominal pain

Question 21

5 day old lethargic baby with sunken fontanelle, hepatomegaly. Breast fed and presents with E coli sepsis. Dx?

Answer 21

Galactosemia: defect in galactose 1 phosphate uridyl transferase= increase in galactose 1 phosphate. Pt will be infant with jaundice, vomiting, hepatomegaly, renal dysfunction

Question 22

pathophys of jejunum or ileum atresia?

Answer 22

vascular injury, often presents with bilious emesis and abdominal distension

Question 23

Pt with family history of colon cancer, endometrial cancer, and presents with adenocarcinoma. Dx?

Answer 23

Mutation in MSH2 (mismatch repair enzyme) = Lynch syndrome.

Question 24

52 yo women with small non obstructing gallstones. How should you treat her?

Answer 24

Bile acid supplement. She has cholesterol gallstones, and administering bile acids will reduce cholesterol secretion and increase biliary bile acid concentration

Question 25

where does H pylori associated antral gastritis create ulcers?

Answer 25

duodenum. Antral gastritis destroys somatostatin in antrum –> increase gastin levels –> increase acid –> more acid entering duodenum

Question 26

39yo man with fever, fatigue, joint pain, and rash. PMH is unremarkable, not married with history of multiple hetersexual partners. elevations in ALT and AST. Dx?

Answer 26

Acute hep B. remember that its not hep C because hep C is often asymptomatic

Question 27

what s abetalipoproteinemia?

Answer 27

AR, loss of function of MTP gene. Lab shows low plasma TG and cholesterol levels, chylomicrons, VLDLs, and apoB are absent

Question 28

What structure is compromised with a tumor at the third part of the duodenum?

Answer 28

SMA. SMA and abdominal aorta sandwhiches duodenum, and if there is an anterior tumor, it can invade the SMA

Question 29

Liver cirrhosis causes gynecomastia. What other symptom has the same pathogenesis?

Answer 29

Spider angiomata due to impaired estrogen in the liver

Question 30

4wk old with jaundice, pale colored stools, high total and direct bili. Dx?

Answer 30

Biliary atresia. Obstruction of extrahepatic bile ducts.

Question 31

marker of biliary tract disease?

Answer 31

alk phos and y glutamyl transferase

Question 32

54yo an with hemochromatosis. Serum ferritin is 1800ug/mL. Where is the genetic defect?

Answer 32

HFE gene (C282Y). HFE normally interacts with transferrin receptor on cell surface to facilitate endocytosis of iron transferrin complex. Impaired HFE = decreased sensing iron = increase intestinal absorption, decrease hepcidin synthesis

Question 33

tubular or villous adenomas are more likely to be malignant?

Answer 33

Villous

Question 34

Pt is coinfected with Hep B and D. How does Hep B allow D to infect?

Answer 34

Hep D has to coated by external coat hep B surface antigen to HBV to penetrate hepatocyte.

Question 35

Cofactor involved in converting nitrogen isotopes into OAA?

Answer 35

Pyridoxine. needed for transaminases

Question 36

PT with gall stones in common bile duct and gallbladder. Stomes are dark brown, soft and composed of calcium bilirubinate. Pathogenesis?

Answer 36

These are pigment stones made from unconjugated bilirubin. Brown stones are usually associated with bacterial infection –> release of beta flucuronidase by injured hepatocytes with increases the amount of unconjugated bili