A 25-year-old woman presents for her first cervical smear.
What is the most important aetiological factor causing cervical cancer?
Correct Answer E: Whilst a number of the above are known to contribute to the development of cervical cancer infection with human papilloma virus 16 & 18 is by far the most important factor.
Cervical cancer: The incidence of cervical cancer peaks around the 6th decade. It may be divided into:
Features:
Risk factors:
*the strength of this association is sometimes debated but a large study published in the Lancet (2007 Nov 10;370(9599):1609-21) confirmed the link.
Which one of the following foodstuffs contains the most calories per unit weight?
Correct Answer B:
Energy from food: The amount of energy that may be derived from 1 gram of food is as follows:
A 24-year-old man is planning an expedition to the Andes. He asks for advice on preventing acute mountain sickness (AMS), other than gradual ascent.
What is the most appropriate advice?
Correct Answer A: Acetazolamide, a carbonic anhydrase inhibitor, has an evidence to support its use in preventing AMS.
Interestingly, there actually appears to be a positive correlation between physical fitness and the risk of developing AMS.
Altitude related disorders: There are three main types of altitude related disorders: acute mountain sickness (AMS), which may progress to high altitude pulmonary edema (HAPE) or high altitude cerebral edema (HACE). All three conditions are due to the chronic hypobaric hypoxia which develops at high altitudes.
Acute mountain sickness is generally a self-limiting condition. Features of AMS start to occur above 2,500 - 3,000m, developing gradually over 6-12 hours and potentially last a number of days:
Prevention and treatment of AMS:
A minority of people above 4,000m go onto develop high altitude pulmonary oedema (HAPE) or high altitude cerebral oedema (HACE), potentially fatal conditions:
Management of HACE:
Management of HAPE:
*The relative merits of these different treatments has only been studied in small trials. All seem to work by reducing systolic pulmonary artery pressure.
Which one of the following causes of primary immunodeficiency is due to a defect in neutrophil function?
Correct Answer E:
Primary immunodeficiency:
Primary immunodeficiency disorders may be classified according to which component of the immune system they affect.
Neutrophil disorders:
B-cell disorders:
T-cell disorders:
Combined B- and T-cell disorders:
The serum potassium is measured in a 1,000 patients taking an ACE inhibitors. The mean potassium is 4.6 mmol/l with a standard deviation of 0.3 mmol/l.
Which one of the following statements is correct?
Correct Answer E: We know that 68.3% of values of a normally distributed variable lie within 1 standard deviation of the mean. This means the range is 4.3 to 4.9 mmol/l.
Normal distribution: The normal distribution is also known as the Gaussian distribution or 'bell-shaped' distribution. It describes the spread of many biological and clinical measurements.
Properties of the Normal distribution:
Standard deviation:
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