Biochemistry Workshop

Question 1

what hormonal disorder can be associated with lung cancer?

Answer 1

SIADH

Question 2

what is the difference between Cushing’s disease and Cushing’s syndrome?

Answer 2

Syndrome = collection of signs and symptoms as associated with increased cortisol

Disease = the above as caused by bilateral pituitary adenoma

Question 3

what are osteolytic lesions?

Answer 3

Osteolytic lesions are areas of damaged bone that appear as holes on XR. They can be caused by a number of factors:

* Cancerous plasma cells: These cells can build up in bone marrow, preventing bones from breaking down and regrowing normally. This can lead to thinner bones that are more likely to fracture... Multiple myeloma

* Metastatic cancer: This is when cancer has spread beyond its original tumor site. 

* Uncontrollable cell division: Cells in the bone can start to divide and multiply uncontrollably.

Question 4

what is the difference between conjugated and unconjugated bilirubin?

Answer 4

Conjugated (water soluble; can travel in blood and be excreted)

Unconjugated (insoluble; can only travel in blood when paired with albumin, cannot be directly excreted)

Question 5

why can jaundice occur in cases of pancreatic cancer?

Answer 5

a carcinoma in the head of the pancreas blocks the bile duct.

this prevents bile from flowing from the liver to the small intestine, causing a build-up of bilirubin in the blood.

Question 6

describe causes of jaundice by build up of both unconjugated and conjugated bilirubin

Answer 6

Unconjugated bilirubin build up
there is increased production of bilirubin, impaired hepatic uptake of bilirubin or decreased conjugation. No dark urine (insoluble; cannot be excreted in this form). Most common cause of jaundice in newborns!

Conjugated bilirubin
the body has difficulty clearing bilirubin, leading to higher levels of conjugated bilirubin in the blood. ex a biliary or gallstone disease, such as gallstones, cholecystitis, or cholangitis. Head of pancreas carcinoma.

Question 7

why do dark urine and pale stools arise?

Answer 7

Dark urine: the excessive bilirubin is excreted through the kidneys

Pale stool: an obstructive or post-hepatic/liver pathology (normal faeces get their colour from bile pigments)

bilirubin cannot get into the gut –> excess excreted via urine instead