Form 30 - NBME

Question 1

what are 2 important structures of the ear developed from nerual crest cells?

Answer 1

cochlear
ossicles

Question 2

Symptoms of:
microcephaly
intellectual disability
growth restriction
congenital heart anomolies
mousy odour
can indicate what inborn metabolism error?

Answer 2

Phenylketonuria (PKU)
caused by enzyme deficiency: phenylalanine hydroxylase (PAH)
**
(BH4 deficiency can also cause this - enzyme deficiency of DHPR - dihydropteridine reductase)

Question 3

how many weeks does hCG maintain the corpus luteum (and thus progesterone) before placenta takes over?
Which cells of the plaenta secretes progesterone?

Answer 3

**8-10 weeks
syncytiotrophoblast of placenta

Question 4

What is contraindicated with OCP use?

Answer 4

Tobacco use (smokers >35yo)
risk of cardiovascular complications

Question 5

What would be potentially deficient in persons who are either vegetarian, celiac, chronic colorectal bleeding or gastric bypass surgery and how up on a blood smear

Answer 5

iron deficiency
microcytic anaemia (microcytes)

Question 6

What X-linked immunodeficiency is likely to present with increased susceptability to catalase + organisms and abnormal dihydrorhodamine test or nitroblue tetrazolium test

Answer 6

chronic granulomatous disease
susceptability to catalase + bacteria (i.e. S. aureus)
therefore likely to see granulomas
abscess - associated bacteria symptoms
tests: dihydrorhodamine will not show green fluouresence
nitroblue tetrazolium will not turn blue

caused by NADPH oxidase defect (in phagocytes - neutrophils, macrophages) - can’t generate ROS - (decreased respiratory burst) - granuloma formation

Question 7

where do osteoclasts derive from?
where do osteoblasts derive from?

Answer 7

monocytes (macrophage line)
mesenchymal stem cells

Question 8

in a condition producing dense yet brittle bones, a mutation in what factor can cause this

Answer 8

M-CSF (CSF-1)
macrophage - colony stimulating factor
osteoclasts are derived from monocytes

impaired differentiation and survivial of osteoclasts (responsible for bone resorption) - causes osteopetrosis

Question 9

what 3 symptoms are in the triad for Caplan syndrome (pneumoconiosis)

Answer 9

lung symptoms - cough, SOB, haemoptysis
multiple lung nodules
rheumatoid arthritis

Question 10

p24 is on the surface of what virus

Answer 10

HIV

Question 11

in patients with SLE that posess the anticardioleptin antibody - what test will produce a false positive

Answer 11

RPR - rapid plasma reagin
syphillis

RPR tests for presence of AB against cardioleptin-cholesterol-lecethin-antigen (reagin AB)

SLE can have:
+ANA,
+anti-dsDNA
active urine sedement
+/-
+antiphospholipid-AB
+anticardioleptin-AB
+antiB2-glycoprotein-1-AB
= predispose to venous/arteril thrombosis, recurrent pregnancy loss