Clinical sciences Flashcards
What features are associated with homocysteinuria?
Downward lens dislocation Myopia DVT/aretrial thrombosis learning difficulty seizures Fine fair hair Arachnodactyly OP kyphosis
What is the treatment of homcytseinuria
vitamin B6 (Pyridoxine)
What is power?
The probability of detecting a statistically significant difference
What is a confidence interval?
Two numbers in between which the true value lies
What is the p value
The probability of obtaining a result by chance at least as extreme as the one that was actually observed, assuming that the null hypothesis is true
Describe X linked recessive conditions
What is the exception to the rule?
if male has it then he has the disease as only has 1 X chromosome
(only males are affected)
Females can only be carriers
Exception = turner’s syndrome as only 1 X chromosome
Commonest cardiac defect in T21?
Endocardial cushion defect
What is the mechanism of metabolic alkalosis in hyperaldosteronism?
aldosterone causes reabsorption of Na+ in exchange for H+ in the distal convoluted tubule
Two examples of type 4 hypersensitivity reactions + mechanism
Tuberculin skin test Graft vs host disease GBS Scabies Allergic contact dermatitis
Mechanism: T cell mediated
Homocysteinuria lens dislocation?
Downward
Examples of type 2 hypersensitivity reactions + mechanism
- Autoimmune haemolytic anaemia
- ITP
- Goodpasture’s syndrome
- Pernicious anaemia
- Acute haemolytic transfusion reactions
- Rheumatic fever
- Pemphigus vulgaris / bullous pemphigoid
Mechanism: Cell bound - IgG/M binds to antigen on cell surface
Machnism + example of T3 hypersensitivity reaction
- Serum sickness
- Systemic lupus erythematosus
- Post-streptococcal glomerulonephritis
- Extrinsic allergic alveolitis (especially acute phase)
Mechanism: Immune complex - Free antigen and antibody (IgG, IgA) combine
Mechanism of T1 hypersensitivity reaction
IgE mediated (bound to mast cell)
Vitamin B1 =
Thiamine (you always forget)
T5 hypersensitivity reaction
Myasthaenia gravis
Graves disease
Commonest cause of trisomy 21
Non dysjunction
How to calculate power of the study?
1 - the probability of a type II error
What are 4 problems associuated
Wernicke’s encephalopathy: nystagmus, ophthalmoplegia and ataxia
Korsakoff’s syndrome: amnesia, confabulation
dry beriberi: peripheral neuropathy
wet beriberi: dilated cardiomyopathy
What is the presentation of dry beriberi?
Peripheral neuropathy
What is the presentation of wet beriberi?
Dilated cardiomyopathy
How to calculate anion gap?
[Na + K] - [HCO3 + Cl]
Treatment of methanol poisoning
Ethanol or fomepizole
What conditions are associated with HLA DR4
T1DM
RA
What condition is associated with HLA DQ2/DQ8
Coeliac disease
In X linked recessive disease what can an affected father only have?
A carrier daughter (Xx)
An unaffected son (xy) - as gives the y to him
(technically rare to have an affected father with a heterozygous mother)
What does IFN gamma do?
Activates macrophages
What type of receptor does insulin bind to?
Tyrosine kinase receptor
What does tropinin C, T and I bind to?
C: calcium
T: tropomysin
I: actin
Treatment of homocysteinuria
vit B6 (pyridoxine) suppliments
What structure overlies L renal hilum?
tail of pancreas
how does alcohol cause hypoglycaemia?
Increased first-phase insulin response
In Duchenne’s and Becker’s muscular dystrophy what is the mechanism?
Telomere shortening in muscle stem cells
What is a defining feature of kallmann syndrome?
ANOSMIA
What is the risk of CF mother having a child with CF (assuming dad is general population risk of carrier [1 in 20])?
1 in 40
How does IgG4 deficiency present?
Recurrent sinus + pulmonary infections
20% have asthma
