Touch important for side-effects of medicines for premature babies with respiratory problems

Discovering that touch is important for the side-effects of a medicine for premature babies with respiratory problems. This is what Sanne Claessens finds so fascinating about fundamental research in medical pharmacology. PhD defence 27 June.

Dexamethason

Claessens studied the effect of dexamethason, a synthetic stress hormone in common use in premature babies with respiratory problems. Dexamethason has a positive effect on the development of the baby's lungs, but it also has negative effects, for example on learning performance later in life. Animal experiments have even indicated a reduced life expectancy. In her animal experiments, Claessens indeed observed short-term side-effects on the development of the brain, effects that could be mitigaged by the use of another medicine administered locally in the brain. The long-term side-effects were shown to be much less negative than Claessens had expected on the basis of earlier research. This can be attributed to the fact that several different factors are at play.  

New to pharmacology

Claessens: 'The effect of dexamethason is influenced by environmental factors.'

In her research Claessens was able to exercise considerable influence on the side-effects. When the researchers picked up the new-born pups on a daily basis to mark them, the side-effects of dexamethason in the long-term were partially eliminated. Handling the pups stimulated the attention of the mother, which resulted in her paying more attention to them, in the form of licking them.  It is well known that the amount of maternal case during early life influences the development of the brain and consequently behaviour in later life.  This is because the degree of maternal care determines the expression of stress genes, via epigenetic modifications. Claessens' research is innovative in terms of the involvement of such an 'environmental factor' in the study of the effectiveness of a medication.  And also in the involvement of a clinical issue in pharmacological research.'

Inluence of environmental factors

Claessens concludes: 'The consequences of treatment with dexamethason are not unequivocal. They are largely influenced by environmental factors, such as material care. This means that the treatment may be sensitive to interventions.  And this means that my discovery may well have clinical implications. In any event, it emphasises the fact that attention needs to be paid to environmental factors such as adequate contact between premature babies in incubators and their parents. This finding emphasises the importance of fundamental research in clinical applications.'