Past test Flashcards

Question

Mechanism of action of trimethoprim?

Answer 1

interferes with DNA synthesis by inhibiting dihydrofolate reductase may, therefore, interact with methotrexate, which also inhibits dihydrofolate reductase

Answer 2

Interactions avoid prescribing trimethoprim or co-trimoxazole concurrently - increases risk of marrow aplasia high-dose aspirin increases the risk of methotrexate toxicity secondary to reduced excretion Methotrexate toxicity the treatment of choice is folinic acid

Answer 3

A conmbination medicadtion containing emtricitabine and tenofavir ## Footnote recommended as first line therapy in the UK It can lead to renal tubular damage

Answer 4

Condition characterised by dilation of the collecting ducts in the papillae with accompanying cystic changes. cyst formation is commonly associated with the development of small calculi in the papillary zones with surounding increased density - this is because the dilated collecting ducts are filled with contrast medium,

Answer 5

Recurrent haemoptysis with segmental collapse is a typical presentation of bronchial carcinoid. Recurrent pneumonia Can rarely cause carcinoid syndrome

Answer 6

urinary 5-HIAA plasma chromogranin A y

Answer 7

somatostatin analogues e.g. octreotide diarrhoea: cyproheptadine may help

Answer 8

an antimetabolite that inhibits dihydrofolate reductase, which interferes with tetrahydrofolate stores required for synthesis of purines and thymidylate in inflammatory cells.

Answer 9

McCune-Albright syndrome is not inherited, it is due to a random, somatic mutation in the GNAS gene. Features precocious puberty cafe-au-lait spots polyostotic fibrous dysplasia short stature

Answer 10

Ehler-Danlos syndrome is an autosomal dominant connective tissue disorder that mostly affects type III collagen. This results in the tissue being more elastic than normal leading to joint hypermobility and increased elasticity of the skin. Features and complications elastic, fragile skin joint hypermobility: recurrent joint dislocation easy bruising aortic regurgitation, mitral valve prolapse and aortic dissection subarachnoid haemorrhage angioid retinal streaks

Answer 11

When the fluid is infected when the pH <7.2 when the gram stains shows the presence of organisms when the fluid is frankly purulent when clinical improvement is slow despite abx therapy

Answer 12

Persistently high FSH and low oestrogen

Answer 13

Fragile X syndrome is a trinucleotide repeat disorder. Features in males learning difficulties large low set ears, long thin face, high arched palate macroorchidism hypotonia autism is more common mitral valve prolapse Features in females (who have one fragile chromosome and one normal X chromosome) range from normal to mild Diagnosis can be made antenatally by chorionic villus sampling or amniocentesis analysis of the number of CGG repeats using restriction endonuclease digestion and Southern blot analysis

Answer 14

Addisons disease autoimmune thyroid disease All woman should be tested for the FMR1 premutation (fragile X) regardless of family history

Answer 15

shown to be as effective as tricyclic antidepressants in the treatment of mild-moderate depression mechanism: thought to be similar to SSRIs (although noradrenaline uptake inhibition has also been demonstrated) **Inducer of the P450 system

Answer 16

hypersomnia cataplexy hypnagogic/hypnopompic hallucinations sleep paralysis

Answer 17

to aid elimination of some drugs that are prone to enterohepatic circulation - charcoal adsorbs drug excreted in bile and prevents reabsorption in the small bowel. typical examples include aspirin, quinine, carbamezapin, phenobarbital and theophylline

Answer 18

Systemic sclerosis (ulcers very unusual in primary raynaud's phenomenon)

Answer 19

Limited scleroderma with systemic involvement -anti-centromere antibody Diffuse scleroderma - scleroderma involving the trunk and proximal limbs as well as face and distal limbs (anti-Scl70 aka anti-topoisomerase-1

Answer 20

MRI is the investigation of choice

Answer 21

Phenytoin induces vitamin K metabolism, which can cause a relative vitamin K deficiency, creating the potential for heamorrhagic disease of the newborn

Answer 22

## Footnote associated with HLA B8, DR3

Answer 23

It is important to consider the rare but relatively benign condition of benign familial hypocalciuric hypercalcaemia, caused by an autosomal dominant genetic disorder. Diagnosis is usually made by genetic testing and concordant biochemistry (urine calcium : creatinine clearance ratio <0.01-distinguished from primary hyperparathyroidism).