MRCP Part One BoFs

1. A 75-year-old man with isolated systolic hypertension, who also has urinary incontinence, gout and asthma, attends outpatients with a blood pressure reading of 190/86 mmHg. Which of the following drugs would you initiate for this patient?

A. Amlodipine
B Atenolol
C Bendrofluazide
D Doxazosin
E Valsartan

Answer: A

Amlodipine, a dihydropyridine calcium-channel blocker, is the drug of choice for the treatment of isolated systolic hypertension in the elderly, especially if thiazides are contraindicated in a patient, as in this man. Doxazosin is contraindicated in patients with urinary incontinence and, similarly, asthma negates the use of ß-blockers.

2. Following a severe stroke, a 52-year-old man complains of difficulty in remembering events, people's names and daily activities. He can remember events that occurred prior to his stroke, but appear unable to form new long-term memories. On neuropsychological testing, he is able to perform tasks such as solving puzzles, visual discriminations and skilled eye–hand co-ordination movements. However, he is unable to consolidate any new information for immediate explicit recall. What would be the most appropriate description of his present condition?

A Retrograde amnesia
B Simple amnesia
C Reverse amnesia
D Anterograde amnesia
E Brain amnesia

Answer: D

Failure to acquire and consolidate new information after trauma, eg severe disease, injury, surgery or malnutrition, is called 'anterograde amnesia'. Although other cognitive abilities remain intact, the patient cannot cope with daily life without help: this is due to major cognitive failure to store immediate learning experiences for long-term memory. The patient's language skills do not seem to be affected since he can carry on a conversation about general events, although he cannot recall them afterwards. The patient can also count backwards and forwards. Such patients tend to require constant care and supervision.

3. Calcium homeostasis is dependent on the fact that:

A. Most of the serum calcium exists as free calcium ions
B. Body calcium content is mainly regulated by kidneys
C. 99% of filtered Ca is reabsorbed in the kidneys
D. Calcitonin increases renal calcium excretion
E. Decreased renal excretion leads to hypercalcaemia in Sarcoidosis

Answer: C

In serum, most of the calcium ion is bound to albumin. Less than 50% of calcium is in the ionised form in serum, the rest being bound to protein and other anions like phosphate, citrate etc. The ionised form is most important in regulation of body functions. Intestinal absorption of calcium is the main regulator of calcium content. This is activated by 1, 25 (OH) 2 D3. Most of the calcium that is filtered by the kidneys is reabsorbed throughout the nephron, around 55% in the proximal convoluted tubule. Calcitonin is the most important factor regulating calcium excretion. Secreted by the parafollicular cells of the thyroid gland, this hormone responds to raised calcium levels by inhibiting bone resorption and increasing renal excretion. Increased intestinal absorption is the main cause for raised calcium levels in Sarcoidosis.

4. A 67-year-old man is referred to the hospital diabetes clinic with a new diagnosis of type-2 diabetes mellitus. He has a BMI of 29. Creatinine level is 150 nmol/l and he has 1+ protein on urinalysis. He has a past history of heart failure. Which of the following drugs are you most likely to prescribe?

A Chlorpropamide
B Gliclazide
C Pioglitazone
D Rosiglitazone
E Metformin

Answer: B

Gliclazide is a sulphonylurea and can be used alone or in combination therapy for type-2 diabetes mellitus. It acts by increasing insulin release from the pancreatic ß-cell. It can be used in mild to moderate renal failure. Pioglitazone and rosiglitazone are thiazolidinediones, which promotes insulin sensitivity by their action on the PPARg receptor (peroxisome proliferator activated receptor-g).They are associated with fluid retention and are contraindicated in heart failure. Chlorpropamide, a sulphonylurea, is rarely used now and is excreted by the kidney. Metformin is a biguanide and, although its mechanism of action is not entirely clear, it reduces insulin resistance and hepatic glucose production. It is thought to be able to cause lactic acidosis in certain circumstances and its use is contraindicated in patients with renal, hepatic or cardiac failure.

5. A 25-year-old man presents to A&E with an acute exacerbation of asthma that is failing to respond to inhaled bronchodilators. As part of the medical team on call you are asked to review him, and you decide to treat him with intravenous magnesium. Which of the following statements is true?

A. The usual dose is 2 mg
B. Magnesium increases acetylcholine release
C. Hypertension is commonly seen after treatment
D. Magnesium relaxes bronchial smooth muscle
E. Drowsiness and coma are features of hypomagnesaemia

Answer: D

Intravenous magnesium (2 g) is now indicated in the management of severe life-threatening acute asthma attacks. Its principal actions are to inhibit acetylcholine release at the neuromuscular junction, relax bronchial smooth muscle and stabilise mast cells. Unwanted effects are uncommon following single-dose therapy, although a slight decrease in blood pressure can be noticed and flushing can occur. Symptoms of Hypomagnesaemia include nausea, diarrhoea, flushing, hypertension, confusion, coma and loss of tendon reflexes.

6. A 27-year-old woman who had previously undergone a terminal ileal and limited right-colon resection for Crohn's disease was seen in clinic. She reported increased diarrhoea but was otherwise well. Investigations showed: CRP < 5 mg/dl; Hb 13.2 g/dl; WCC 8.6 × 109/l; platelets 244 x 109/l. Repeat colonoscopy was normal to the neoterminal ileum; a barium follow-through showed a normal mucosa; and a lactose hydrogen breath test was normal. What is the most likely cause of her diarrhoea?

A Bile-salt malabsorption
B Collagenous colitis
C Mesalazine
D Primary sclerosing cholangitis
E Small-bowel bacterial overgrowth

Answer: A

Bile-salt malabsorption causes a secretory diarrhoea. Bile salts usually undergo enterohepatic circulation, being reabsorbed in the terminal ileum. Post-surgery, this system fails and so malabsorption occurs. There is a theoretical failure of absorption of fat-soluble vitamins; however, this rarely becomes clinically significant. Treatment is with a bile-salt binder (cholestyramine).
Collagenous colitis is a thickening of the subepithelial collagen band resulting in diarrhoea. It is associated with Coeliac disease. Mesalazine can cause bowel frequency, but rarely true diarrhoea. Primary sclerosing cholangitis is not a cause of diarrhoea. Bacterial small-bowel overgrowth is rare but may occur after surgery. The lack of an early peak on the breath test counts against this.

7. A 40-year-old diabetic is receiving insulin. Which of the following enzymes is most likely to be inhibited by insulin?

A Glucose 6-phosphate dehydrogenase
B Pyruvate carboxylase
C Glycogen synthetase
D Acetyl-CoA carboxylase
E ATP citrate lyase

Answer: B

Insulin inhibits gluconeogenesis by inhibiting the enzymes involved in the process. Pyruvate carboxylase is an enzyme involved in gluconeogenesis, hence its action is inhibited by insulin. Insulin increases glycogenesis in the liver and muscle by stimulating glycogen synthetase. Insulin activates the hexose monophosphate (HMP) shunt by inducing the synthesis of glucose 6-phosphate dehydrogenase. Both acetyl-CoA carboxylase and ATP citrate lyase are stimulated to increase the synthesis of fatty acids.

8. A 19-year-old man is being treated for tuberculosis and complains of numb feet. Nerve conduction studies (NCS) show: Sural sensory action potential 8 mV (> 15 mV)
Median sensory action potential 9 mV (> 20 mV)
Common peroneal nerve action potential 50 m/s (> 45 m/s)
What drug is most likely to have caused this problem?

A Rifampicin
B Isoniazid
C Pyrazinamide
D Ethambutol
E Paracetamol

Answer: B

The NCS values above are consistent with an axonal neuropathy that is classically caused by isoniazid.

9. A 26-year-old Asian woman complains of back pain and tenderness in her thighs. She also mentions that she finds it difficult to climb stairs. She has never smoked and does not drink alcohol. She has well-controlled asthma and takes a low-dose inhaled corticosteroid only. Her full blood count is normal. She has an alkaline phosphatase level of 250 U/l (normal, 40–125 U/l); her plasma calcium concentration is 1.98 mmol/l (normal, 2.12–2.62 mmol/l). Her liver and kidney function tests are normal. What would you expect her pelvic radiograph to show?

A Decreased bone density
B Translucent bands
C Punched-out osteolytic lesions
D Bone expansion and sun-ray appearance
E Layers of periosteal new bone formation

Answer: B

This woman has osteomalacia, which is characterised by translucent bands (Looser's zones or pseudofractures) at points of stress. Osteomalacia is characterised by back pain, muscle weakness and bone tenderness. It is due to vitamin D deficiency. Biochemical abnormalities are a raised alkaline phosphatase and low calcium and phosphate levels.

10. A woman who has recently used cocaine presents to A&E saying she can feel insects crawling under her skin. What is this symptom known as?

A. Illusion
B. Haptic hallucination
C. Visual hallucination
D. Delusion of infestation
E. Auditory hallucination

Answer: B

This is the sensation of feeling insects in the absence of a stimulus, and is therefore a haptic hallucination. Haptic hallucinations can be interpreted in a delusional way and can lead on to delusional beliefs of infestation. This sensation of crawling insects is also known as the ‘cocaine bug’ and is associated with the ingestion of high doses of cocaine. Cocaine use can also lead to an acute toxic psychosis, with marked agitation, paranoia, auditory and visual hallucinations.