Which one of the following statements regarding allergy testing is incorrect?
Correct Answer D:
Skin prick testing can be read after 15-20 minutes. Skin patch testing is read after 48 hours.
Allergy tests:
Which one of the following types of blood vessel is first to vasoconstrict in the presence of hypoxia?
Correct Answer E:
Pulmonary arteries vasoconstrict first in the presence of hypoxia.
Respiratory physiology: hypoxia:
A fall in the partial pressure of oxygen in the blood leads to vasoconstriction of the pulmonary arteries. This allows blood to be diverted to better aerated areas of the lung and improves the efficiency of gaseous exchange.
You review a 30-year-old man shortly after he is discharged from the Intensive Care Unit after being admitted with pneumococcal pneumonia. This is his second admission in 18 months with a severe pneumonia. During his first admission Hemophilus influenzae was grown from his sputum. He also describes having frequent episodes of sinusitis and recurrent skin abscesses.
Which one of the following complement deficiencies is he most likely to be suffering from?
Complement deficiencies:
Complement is a series of proteins that circulate in plasma and are involved in the inflammatory and immune reaction of the body. Complement proteins are involved in chemotaxis, cell lysis and opsonization.
C1 inhibitor (C1-INH) protein deficiency:c
C1q, C1rs, C2, C4 deficiency (classical pathway components):
C3 deficiency:
C5 deficiency:
C5-9 deficiency:
Which one of the following features is least commonly seen in patients with pseudoxanthoma elasticum?
Correct Answer B:
Pseudoxanthoma elasticum:
Pseudoxanthoma elasticum is an inherited condition (usually autosomal recessive*) characterised by an abnormality in elastic fibres.
Features:
*There are reports of autosomal dominant inheritance in a minority of cases
T-Helper cells of the Th1 subset typically secrete:
Correct Answer B: T-Helper cells:
There are two major subsets of T-Helper cells:
Th1:
Th2: