Tuesday, 1 May 2012

The Experiments (a guest post by Dr. Phil Ainslie)

Sorry for the vagueness of our experiments so far (this is entirely my fault as I’ve not contributed to the blog despite Greg hounding me everyday). The main ones happen when we get to the lab in about 4-5 days time. However, to keep us (read PhD students) out of too much trouble, we are conducting a few experiments en route to the lab. The idea of doing them en route is to help understand how our bodies’ change with progressive ascent to 5000m. A brief overview of these include:

1.     Blood flow to the brain upon ascent to high altitude. For this experiment, we measure blood flow to the brain using ultrasound techniques. We do this at around 3500 m, 4200 m and at 5000 m. We also are making these measurements in groups of Sherpa’s (i.e. a population born and bred and adapted to high altitudes). The idea of doing these studies is to see if changes in blood flow to the brain are important in causing migraine like headaches which most of will have at 5000 m.  These experiments are also important in helping is understand how low levels of oxygen may negatively influence our ability to maintain a constant oxygen supply to our brain. Such low levels of oxygen are also common in conditions like lung disease and heart failure.

2.     Heart function in Sherpa children living at 3500 m. One of the many unique aspects of being at high altitude is that the pressures in our lungs increase. This is not a good thing of course! Whilst we know a little bit about the cause and consequences of how and why such pressure in the lungs develop in adults at high altitude (and various pathologies at sea-level), we know nothing about the development of these pressures in children at high altitude. We are very fortunate to have good support from a local hospital nearby in Kunde, located at 3900 m. So for these experiments we estimate pressure in the lungs using ultrasound and also how these pressures may influence normal heart function. We are testing 20-30 children between the ages of 8-14 who have been born and live at 3500 m. As controls, we have tested children who were previously born and lived at 3500 m but have moved to lower altitudes (1400 m). We will also see how heart function in these groups compare to children born and raised at sea-level in the UK. We ultimately hope to understand the relationship between pressure in the lungs and heart function.

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