Flashcards in Liver Deck (12)
Brown pigment stones
Radiolucent. Biliary tract infection. Commonly seen in Asians.
Cholesterol stones, pigment stones, mixed stones
Black pigment stones
Radio-opaque (appear on x-ray) because they contain high amounts of calcium carbonate and phosphates. Calcium bilirubinate + calcium carbonate.
Chronic extravascular hemolysis - when increased unconjugated bilirubin precipitates in bile as calcium bilirubinate.
Small, spiculated, crumbly.
Black versus brown pigment stones - radiolucent or opaque?
Black: radio-opaque, brown: radio-lucent.
Converts cholesterol into bile acids.
Suppressed by fibrates (benzafibrate, fenofibrate, ciprofibrate).
If this is suppressed, increased concentration of cholesterol in bile. When gallbladder is hypomotile or there is more cholesterol than can dissolve, cholesterol precipitates into insoluble crystals. These eventually make gallstones.
Radiolucent with 10-20% opaque due to calcium carbonate. Usually stones of mixed composition. Stones contain CH, Calcium carbonate, some bilirubin pigment.
80% of gallstones.
- Crohn's Disease
- Advanced age
- Estrogen therapy
- Rapid wt loss
- Native American origin
REMEMBER: RISK FACTORS - THE 4 FS:
- FERTILE (PREGNANT)
Necessary for cholesterol biosynthesis; specifically catalyzes the HMG-CoA to mevalonate reaction. So decreased functionality of this enzyme would decrease cholesterol biosynthesis and discourage cholesterol gallstone formation.
Estrogen and cholesterol biosynthesis
Estrogen increases hepatic HMG-CoA reductase activity.
Thus, OCPs are a risk factor for cholesterol gallstones.
Aromatase and cholesterol biosynthesis
Aromatase catalyzes androgen --> estrogen conversion.
Estrogen increases hepatic HMG-CoA reductase activity. OCPs are a risk factor for cholesterol gallstones.
Deconjugates bilirubin. Bilirubin glucuronides get hydrolyzed. Associated with brown pigment stones - injured hepatocytes release beta glucuronidase and unconjugated bilirubin in the bile increases.
Typically contains cholesterol monohydrate crystals, calcium bilirubinate, and mucus. Known precursor to stone formation.