Clinical Sciences

Question 1

Type 1 HS reaction

Answer 1

Anaphylactic - Antigen reacts with IgE which is bound to mast cells

Examples - General Atopy / Anaphylaxis

Question 2

Type 2 HS reaction

Answer 2

Cell Bound - IgG or IgM binds to antigen on cell surface

Examples - AI haemolysis, pemphigoid, Acute haemolytic reactions, ITP, pernicious anaemia

Question 3

Type 3 HS reaction

Answer 3

Immune complex - Freen antigen and antibody bind

Examples - EAA, SLE. Post strep GN and serum sickness

Question 4

Type 4 HS Reaction

Answer 4

Delayed - T cell mediated

TB
G vs H
Scabies
Allergic dermatitis
MS
GBS

Question 5

Tumour suppressor genes

Answer 5

These genes normally control the cell cycle so when you lose / impair their function there is an increased risk of cancer

Rb - Retinoblastoma
p53 - many cancers
BRCA
APC - CRC
NF1 - Neurofibramatosis
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Question 6

Drugs to Avoid in pregnancy

Answer 6

Abx - CIpro, tetracyclines, Sulphs and chloramphenicol

Psych - Lithium and BNZD

Aspirin

Carbimoalzole

Amiodarone

Methotrexate

Sulfonylureas

Question 7

Cardiac Action Potential

Answer 7

Split into numerous stages

Rapid depolarisation - 0 - Rapid influx of NA+ - reaches +30mV

Early repolrisation - 1 - slow efflux of potassium

Plateau phase - 2 - Slow influx of Calcium ions (L channels) but no more sodium influx

Repolarisation - 3 - Calcium ion stop moving in and fast K+ efflux - makes more negative.

Resting Potential - 4 - Na+/K+ ATPase pump restores via slow influx of sodium into cell

Question 8

Oncogenes

Answer 8

Cancer promoting genes that derise from normal genes called proto-oncogenes. They become ongonenes via mutation, translation or increased protein expression.

They cause a gain in function and increase risk of cancer

ABL - CML
c-MYC- Burkitts
n-MYC - Neuroblastoma
RET - MEN 1 and 2
RAS - Pan`creatic

Question 9

ATN

Answer 9

Most common cause of AKI

Causes can be split into ischaemia (sepsis and shock) and toxins (rhabdo, contrast and aminoglycosides)

You get:
Necrosis ot tubules - loss of their nuceli and detachment from the basement membrane
Blockage of tubules by necrotic cells
Tubule dilatation

Key feature is muddy brown casts in urine

Question 10

Metabolic Alkalosis

Answer 10

Either causes by gain of bicarbonate or loss of hydrogen ions

Vomiting and diarrhoea
Diuretics
Low potassium
Cushings
Primary Hyperaldosteronism

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Question 11

HLA associations

Answer 11

HLA antigens are encoded for by genes on chromsome 6.

HLA A3 - haemochromatosis

B51 - Bechets

DQ2/DQ8 - coeliacs

DR2 - narcolepsy and goodpastures

DR4 - T1DM + RA

DR3 - PBC, sjogrens and dermatitis herpetiformis

Question 12

Vitamin B1

Answer 12

Thiamine!

Important function in the catabolism of sugars and amino acids so issues with it affect tissues with high metabolic rate ie the brain and heart

Def can be caused by excessive alcohol and malnutrition

Wet beriberi - cardiomyopathy
Dry - Peripheral neuropathy
Korsakoffs and wernickes

Question 13

Clinical Features of Downs syndrome

Answer 13

Complciations
- Hypothyroid
Short
- LD
- Alzheimers
-Sunfertility
- Atlantoaxial instaility
- ALL

Cardiac:

• Endocardial cushion defect - most common
• VST
• AST
  Tetraoly