lecture 7 - hyperuricemia

Question 1

what are the purine bases

Answer 1

guanine

adenine

Question 2

clinical implications that can occur after purine catabolism

Answer 2

uric acid enters blood -> excretion

uric acid ionises with NA+ -> leads to urate crystals forming -> inflammation in joints

Question 3

what are the pyrimidines

Answer 3

thymine
cytosine
uracil

Question 4

what are the steps of catbolism of purines

Answer 4

dephosphorylation of nucleotide

deamination and ribose hydrolysis

oxidation to form uric acid

Question 5

how do we obtainin purines

Answer 5

1. diet - red meat shell fish
2. denovo synthesis
3. salvage pathway

Question 6

salvage pathway for adenine

Answer 6

1. taken from food
2. converted to AMP using APRT
3. attaches to a phosphate group from PRPP to adenine

Question 7

salvage pathway for guanine

Answer 7

1. taken from food
2. converted to GMP using HGPRT
3. attaches to phosphate group from PRPP to guanine

Question 8

what is de novo synthesis

Answer 8

cells can synthesis purine from other precursor molecules

in liver

Question 9

what enzymes are involved in de novo synthesis

Answer 9

PRPPS
ATase

Question 10

how is gout caused

Answer 10

ingestion of large quantities of purine rich foods and alcohol

Question 11

what is gout

Answer 11

an inflammatory disease by formation of urate crystals in synovial fluid

Question 12

what is a biomarker for gout

Answer 12

elevated uric acid

Question 13

why does hyperuricaemia occur

Answer 13

uric acid is elecated

Question 14

what is PRPPS superactivity

Answer 14

enzyme becomes continuously acitvated

Due to mutations in the PRPS1 gene

Question 15

what is Von Girke’s disease

Answer 15

glycogen storage disease due to g6p deficiency

Question 16

what are characteristics of hyperuricaemia

Answer 16

diet rich in purines

increased turnover of nucleic acids

accelerated purine degradation
increased ATP degradation

decreased excretion from kidneys

Question 17

four stages of gout

Answer 17

asymptomatic

acute

inter critical

chronic tophaceous

Question 18

Uric acid reference ranges

Answer 18

Male: 0.1-0.46 mmol/L

Female 0.1-0.36

Question 19

Treatment of hyperuricaemia

Answer 19

Reduce purine rich foods

Corticosteroids

Uricosuric drugs

Question 20

how is secondary hyperuricaemia caused

Answer 20

excess alcohol intake

increased turnover of nucleic acids

decreased excretion from kidneys caused by renal disease

Question 21

how is gout diagnosed

Answer 21

patient history

physical examination of joint

test for hyperucaemia

Question 22

cause of HYPOuricaemia

Answer 22

low serum urate

Question 23

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