55-year-old woman undergoes a cholecystectomy; The gallbladder contains multiple dark irregular small stones. The most likely cause of this type of gallstone is an increased blood level of:

A 36-year-old man presents with a two-month history of low back pain radiating to his left leg After clinical examination he is referred for an MRI scan. This shows a prolapsed intervertebral disc. The clinical signs are consistent with pressure on SI roots. Which combination of clinical signs is most likely?

A 20-year-old man with a severe head injury is being ventilated using intermittent positive pressure. Which of the following is a physiological consequence of this? (April & Sep)

A 3-year-old boy is admitted to hospital with severe vomiting. Radiographic examination reveals that he is suffering from annular pancreas. Which of these structures is constricted?

A 65-year-old man remains on the high dependency unit following a gastrectomy, three days previously. His urine output: has averaged 80ml/hour for the last 24 hours. He has one dry abdominal drain arid no nasogastric losses: His urea and electrolytes are normal He is to stay nil by mouth for a further 24 hours. Which of the following fluid regimes is most appropriate to his electrolyte and water requirements over the next 24 hours? (April & Sep)