Recent observations concerning RNA methylation and polyamine metabolism in cystic fibrosis. pp. 223-41.

Determination of fibroblast proliferation rates and RNA methylation patterns in our laboratory 
has revealed no alteration in cells from cystic fibrosis patients. Blood 
polyamines are located predominantly in erythrocytes with low concentrations in plasma; 
sweat has likewise been shown to have a low content of 
spermidine and spermine. Whole blood polyamine concentrations fluctuate from one individual 
to another and are especially variable in females subject to the 
hormonal changes of the menstrual cycle. Because of the variability in 
the spermidine and spermine content of blood, it is useful to 
express such data on the basis of the spermidine/spermine ratio; however, 
results must be analyzed according to sex and, in the case 
of females, should be interpreted in relationship to the menstrual cycle. 
Spermidine/spermine ratios are significantly elevated in whole blood extracts and isolated 
erythrocytes from male CF homo- and heterozygotes. 