Dear friends - We have 25 rats, 14 of these subjected to partial removal of kidney tissue, 11 to sham operation, and then followed for 6 weeks. So far we have data on 26 urine metabolites measured by NMR 7 times during the observation. I have smoothed the measurements by b.splines in fda including a roughness penalty, and inspecting the mean curves for nephrectomized and sham animals indicate differences for several of the metabolites. Now the real idea is to use the NMR measurements to understand what goes on in the kidneys since we know the partial removal of kidney tissue will result in progressive damage in the kidneys - the nature of that is what we want to understand. We have a blood sample from the rats just prior to sacrifice, and the creatinine concentration there is a good proxy for "renal function". So the course of concentrations of the metabolites are thought to be valuable in understanding the physiology. Some of these are thought to be correlated. We have two groups where sham animals have better renal function than partially nephrectomized, but there is variation in both groups which is also interesting - some animals progress more rapidly after "the same operation" than others - we would like to know why. The data are available (eventually - the resulting blood tests still are missing) if anyone would like to have a look but the main issue is if it is at all feasible to make fda work on such a problem.
Best wishes
Troels Ring,
Nephrology
Aalborg,  Denmark

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