Which one of the following causes of primary immunodeficiency is due to a defect in both B-cell and T-cell function?
Correct Answer E:
Combined B- and T-cell disorders: SCID WAS ataxic (SCID, Wiskott-Aldrich syndrome, ataxic telangiectasia).
Primary immunodeficiency:
Primary immunodeficiency disorders may be classified according to which component of the immune system they affect:
1- Neutrophil disorders:
2- B-cell disorders:
3- T-cell disorders:
4- Combined B- and T-cell disorders:
Which type of secondary messenger system does adrenaline stimulate?
Correct Answer D:
Second messengers:
Overview:
Cyclic AMP:
Protein kinase activity:
Calcium and/or phosphoinositides:
Cyclic GMP:
A patient who takes bendroflumethiazide is noted to have a potassium of 3.1 mmol/l.
What is the main mechanism causing hypokalaemia in patients taking bendroflumethiazide?
Correct Answer B:
Bendroflumethiazide - mechanism of hypokalaemia:
Increased delivery of sodium to the collecting ducts causes the sodium-potassium exchanger to release more potassium into the urine. Another cause is activation of the renin-angiotensin aldosterone system secondary to hypovolaemia.
Bendroflumethiazide:
Bendroflumethiazide (bendrofluazide) is a thiazide diuretic which works by inhibiting sodium absorption at the beginning of the distal convoluted tubule (DCT). Potassium is lost as a result of more sodium reaching the collecting ducts. Bendroflumethiazide has a role in the treatment of mild heart failure although loop diuretics are better for reducing overload. The main use of bendroflumethiazide was in the management of hypertension but recent NICE guidelines now recommend other thiazide-like diuretics such as indapamide and chlortalidone.
Common adverse effects:
Rare adverse effects:
Each one of the following is seen in Klinefelter's syndrome, except:
Klinefelter's syndrome:" Klinefelter's syndrome is associated with karyotype 47, XXY.
Features:
Diagnosis:
A 69-year-old female with a history of multiple myeloma is admitted with confusion.
The following results are obtained:
What is the most appropriate initial management?
The raised sodium is a function of dehydration and will correct once the patient is adequately rehydrated.
Hypercalcaemia: management:
The initial management of hypercalcaemia is rehydration with normal saline, typically 3-4 litres/day.
Following rehydration bisphosphonates may be used. They typically take 2-3 days to work with maximal effect being seenat 7 days.
Other options include:
There is a limited role for the use of furosemide in hypercalcaemia. It may be useful in patients who cannot tolerate aggressive fluid rehydration.
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