Chemical pathology

Question 1

Which LFT is most raised in alcoholic liver disease, and chronic alcohol use?

Answer 1

AST, GGT

Question 2

Where in the liver is ALP produced?

Answer 2

Sinusoidal and canalicular membranes

Question 3

In which conditions is AFP raised?

Answer 3

Hepatocellular carcinoma, pregnancy, testicular cancer

Question 4

What is/isn’t detected in the urine of someone with obstructed jaundice?

Answer 4

Increased conjugated bilirubin, dark urine, absent urobilinogen

Question 5

What is fasting bilirubin used to diagnose?

Answer 5

Gilberts syndrome

Question 6

What is courvoisier’s sign?

Answer 6

in the presence of a painless palpable GB, jaundice is unlikely to be caused by gallstones.

Question 7

What biochemical abnormality common presents with depression

Answer 7

Hypercalcaemia

Question 8

What is a Pott’s fracture?

Answer 8

Ankle fracture involving the tibia and fibula

Question 9

What are the effects of PTH?

Answer 9

efflux of ca from bone, decreased urine ca loss, enhanced intestinal ca absorption, increased phosphate urinary excretion, enhances 1a hydroxylase

Question 10

How does hypercalcaemia cause polydipsia/polyuria?

Answer 10

Nephrogenic DI

Question 11

What type of renal stones tend to form staghorns?

Answer 11

Struvite (magnesium ammonium phosphate)

Question 12

Which is the commonest causative organism of renal stone infections?

Answer 12

Proteus

Question 13

Which tumours are associated with MEN1 and MEN2?

Answer 13

MEN1: pituitary, pancreas, parathyroid
MEN2: parathyroid, thyroid, phaeo

Question 14

When would you give pamidronate for hypercalcaemia?

Answer 14

Cancer patients for pain relief of bony mets

Question 15

What is the most important immediate management of hypercalcaemia?

Answer 15

IV 0.9% saline

Question 16

Which type of diuretics are avoided in hypercalcaemia and why?

Answer 16

Thiazides - increase Na/Ca anti porter, so more Ca is absorbed from lumen into cells.

Question 17

What bone changes are associated with hyperparathyroidism?

Answer 17

Osteitis fibrosa cystica (brown tumours), giant multinucleate cells

Question 18

Why does sarcoidosis cause hypercalcaemia?

Answer 18

Ectopic 1a hydroxylase production by macrophages

Question 19

Which organs produce ALP?

Answer 19

Liver, bone, intestines, placenta

Question 20

What is the most specific marker of acute pancreatitis?

Answer 20

Pancreatic lipase

Question 21

Causes of a raised serum amylase?

Answer 21

Acute pancreatitis, mumps parotitis, acute abdomen

Question 22

In relation to the onset of chest pain, when should troponin be measured?

Answer 22

6 and 12h after

Question 23

What are the other names for vitamin B1,2,3,6 and 12

Answer 23

Thiamine, riboflavin, niacin, pyridoxine, cobalamin

Question 24

What is the presenting triad of wernicke’s encephalopathy and what causes it?

Answer 24

ophthalmoplegia, ataxia, and confusion

B1 (thiamine) deficiency

Question 25

What are the 4 components contributing to daily energy expenditure?

Answer 25

* Resting energy expenditure * Exercise * Thermogenesis * Facultative thermogenesis

Question 26

What are 2 medications for obesity and how do they work?

Answer 26

Orlistat- inhibit pancreatic lipase | GLP-1 agonist- e.g. exanetide. increase satiety

Question 27

How is ALP affected in osteomalacia and why?

Answer 27

Increased due to 2ry hyperparathyroidism

Question 28

Which enzyme is most raised in viral hepatitis?

Answer 28

ALT

Question 29

What happens to vitamin D levels in primary hyperparathyroidism and why?

Answer 29

Reduces, as 1a hydroxylase uses up vitamin D

Question 30

What are the main indications for dialysis?

Answer 30

"AEIOU"-"A"- intractable acidosis; "E"- electrolyte disarray ( K+, Na+, Ca++); "I" - intoxicants (methanol ethylene glycol, Li, ASA); "O"- intractable fluid overload; "U"- uremic symptoms (nausea, seizure, pericarditis, bleeding).


Question 31

How to manage hyperkalaemia?

Answer 31

calcium gluconate, 50ml 50% dextrose and insulin

Question 32

Marker of glucose control over last 3 weeks, and what does it represent?

Answer 32

fructosamine 
- fraction of total serum proteins that are glycated (mainly albumin)

Question 33

What are the 3 main causes of a metabolic acidosis?

Answer 33

- H+ loss (i.e. vomiting) - Hypokalaemia - Ingestion of bicarbonate

Question 34

What are the 3 main causes of hypokalaemia?

Answer 34

- intestinal loss (d&v, fistula) - renal loss (mineralocorticoid excess, diuretics, renal tubular disease) - redistribution (insulin, alkalosis)

Question 35

How does hypokalaemia cause alkalosis in terms of cells, and the kidneys?

Answer 35

Cells 1. H+ moves into cells (due to lack of K for exchange with Na) Kidneys: 1. H is exchanged with Na), and kidneys increases H+ secretion (in exchange for Na) --> acidic urine 2. Generation of bicarbonate

Question 36

How does alkalosis cause hypokalaemia in terms of cells, and the kidneys?

Answer 36

K moves into cells (instead of H+), and kidneys increases K+ secretion

Question 37

What are the possible causes of cushing's syndrome?

Answer 37

pituitary, ectopic ACTH, adrenal tumour, iatrogenic

Question 38

How does ectopic ACTH cause hypokalaemia

Answer 38

VERY high levels of cortisol can bind to aldosterone receptor

Question 39

Which type of thyroid cancer is associated with MEN2?

Answer 39

Medullary