USMLE RX

Question 1

features of trptophan deficiency

Answer 1

also called niacin
- dementia, diarrhoea, dermatitis
(pellagra)

Question 2

what mode of inheritance is haemochromatosis

Answer 2

autosomal recessive

Question 3

what mode of inheritance is CF

Answer 3

autosomal recessive

Question 4

what mode of inheritance is hereditary spherocytosis

Answer 4

autosomal dominant

Question 5

what mode of inheritance is glucose-6-phosphate dehydrogenase deficiency

Answer 5

x-linked recessive

Question 6

what vitamin is biotin and when is it found

Answer 6

vitamin B7
excessive ingestion of egg whites, antibiotic use

Question 7

alcoholic hypoglycaemia results due to an increase in what metabolite ratio

Answer 7

NADH:NAD
increased NADH to the liver inhibits gluconeogenesis

Question 8

in alcohol intoxication does serum Na go high or low

Answer 8

remains normal
serum osmolality increases with normal Na

Question 9

presentation of glucose-6-phosphate deficiency

Answer 9

infancy
hepatomegaly
hypoglycaemia
lactic acidosis
(unable to convert G6P to glucose which causes accumulation of glycogen in the liver so results in hypoglycaemia. different from other glycogen storage diseases due to hepatomegaly)

Question 10

presentation of galactosaemia

Answer 10

infantile cataracts
hepatomegaly
vomiting and jaundice
occurs upon ingestion of formula milk

Question 11

presentation of alpha-1,6 - glucosidase (cori disease)

Answer 11

hypotonia
wasting
hypoglycaemia
hepatomegaly
elevated CK

Question 12

primary prevention

Answer 12

i.e. vaccines
preventing onset of a disease

Question 13

seocndary prevention

Answer 13

i.e. smear tests
early identification of disease before symptom onset

Question 14

tertiary prevention

Answer 14

treating symptomatic disease

Question 15

primordial prevention

Answer 15

minimising risk factors that put people at risk of disease

Question 16

quartenary prevention

Answer 16

prevents over treatment in patients being treated for a disease, to suggest ethically acceptable alternatives

Question 17

corkscrew spirochete

Answer 17

borellia burgdorferi (lyme disease)
(Ixodes tick)

Question 18

gram negative bacterium that causes a positive weil felix reaction

Answer 18

rickettssia rickettsi

Question 19

hapten formation stimulating T cell formation

Answer 19

non-IgE mediated drug reactions

Question 20

features of hypomagnaesemia

Answer 20

diminished deep tendon reflexes
PR prolongation
associated with CKD

Question 21

what chromosome is NF found on

Answer 21

22

Question 22

what pharyngeal arch is the ductus arteriosus derived from

Answer 22

6th

Question 23

what is the thyroglossal duct derived from

Answer 23

primitive floor of pharynx

Question 24

what are the parafollicular C cells derived from

Answer 24

4th pharyngeal arch

Question 25

what are the thyroid follicular cells derived from

Answer 25

endoderm

Question 26

what cells degrade histamine and leukotrienes

Answer 26

eosinophils

Question 27

what type of immune cell localise along blood vessel walls

Answer 27

neutrophils

Question 28

what cells ingest bacteria in the sequestrial immune response

Answer 28

macrophages

Question 29

what cells modulate the immune response and develop in the thymus

Answer 29

T cells

Question 30

what cells release histamine and heparin

Answer 30

basophils

Question 31

name 3 conditions which are examples of type II hypersensitivity reactions

Answer 31

goodpastures graves rheumatic fever

Question 32

name 2 conditions which are type III hypersensitivity reactions

Answer 32

SLE polyarteritis nodosa

Question 33

name 2 conditions which are type IV hypersensitivity reactions

Answer 33

MS T2DM

Question 34

genetic defect in myotonic dystrophy

Answer 34

CTG trinucleotide repeat autosomal dominant anticipation

Question 35

presentation of myotonic dystrophy

Answer 35

myopathy muscle weakness hypotonia unable to relax muscles cataract

Question 36

immunoglobulins responsible for warm and cold autoimmune haemolytic anaemia

Answer 36

warm IgG (greatly warm) cold IgM (mega cold)

Question 37

UTI with causative organisms bile insensitivity and haemolysis

Answer 37

enterococcus

Question 38

UTI with hydrogen sulphide positive

Answer 38

proteus salmonella

Question 39

kidney stones not visible on XR

Answer 39

urate

Question 40

what layers of the skin are affected in psoriasis

Answer 40

hyperkeratosis of stratnum corneum and hyperplasia of stratnum spinosum

Question 41

what layer of the skin is affected in lichen planus

Answer 41

hyperkeratosis of stratnum granulosum

Question 42

what molecule is responsible for transport from prophase to metaphase in the cell cycle

Answer 42

B tubulin

Question 43

function of topiosomerase in cell cycle

Answer 43

unwinds DNA for replication

Question 44

function of TP53 in the cell cycle

Answer 44

arrests cell progression from G1 to S phase

Question 45

function of Rb in cell cycle

Answer 45

arrests cell progression from G1 to S phase

Question 46

pathophysiology of Galactosaemia

Answer 46

galactose-1-uridyltransferase deficiency (GALT) leads to accumulation of galactose-1-phosphate and galactitol

Question 47

derivative of 1st pharyngeal pouch

Answer 47

eustachian tube, middle ear, mastoid air cells

Question 48

derivative of 2nd pharyngeal pouch

Answer 48

epithelial lining of palatine tonsil

Question 49

derivative of 3rd pharyngeal pouch

Answer 49

dorsal - inferior parathyroid ventral - thymus

Question 50

derivative of 4th pharyngeal pouch

Answer 50

dorsal - superior parathyroid ventral - parafollicular C cells

Question 51

antibiotics to avoid in pregnancy

Answer 51

SAFe Children Take Good Care sulphonamides aminoglycosides flouroquinolones chloramphenicol tetracyclines griseofulvan clindamycin

Question 52

pathophysiology of gilberts syndrome

Answer 52

reduced UDP glucoronyltransferase resulting in build up of unconjugated bilirubin in times of stress/illnes

Question 53

pathophysiology of dubin-johnson syndrome

Answer 53

impaired excretion of conjugated bilirubin resulting in conjugated hyperbilirubinaemia

Question 54

pathophysiology of crigler najjar syndrome

Answer 54

total absent UDP glucoronidyl transferase presents early in life with jaundic, kernicterus and unconjugated hyperbilirubinaemia requires liver transplant, phototherapy and plasmophoresis type II is less severe form and can be treated with phenobarbital which increases liver enzymes

Question 55

pathophysiology of rotter syndrome

Answer 55

impaired hepatic storage of conjugated bilirubin = elevated conjugated bilirubin levels phenotypically similar to dubin-johnson but less severe and no black liver