C ardiovascular disease underlies the majority of deaths in patients with dialysis-dependent end-stage renal disease (ESRD). 1 Standard cardiovascular therapies have rarely been tested in this population and with disappointing results. For example, 3 trials of HMG-CoA reductase inhibitors found that neither overall nor cardiovascular mortality was reduced in hemodialysis (HD) patients treated with statins compared with placebo. 2-4 These and other findings highlight the need to evaluate therapies to reduce cardiovascular morbidity and mortality specifically in patients receiving maintenance dialysis. 5 Several lines of evidence suggest that in ESRD, the heart undergoes progressive fibrosis and rarefaction of the microvasculature, 6-8 structural changes that predispose to arrhythmias and contribute to heart failure by reducing
The complex origin of urinary 17-ketosteroids on the one hand, and the need for technical simplicity on the other, make it desirable to have available a series of analytical methods. In some circumstances it may be sufficient to obtain a simple overall measurement which is highly non-specific; in others it may be desirable to measure, with greater specificity and at the cost of greater complexity, the 11-deoxy and/or the 11-oxy ketosteroid moieties; in still other circumstances it may be important to assess the excretion of the individual ketosteroids with methods of high precision and specificity, but of proportionately greater technical complexity. Various procedures have been investigated, especially with respect to accuracy and specificity. Hydrolysis with perchloric acid in tetrahydrofuran produces the same extensive destruction found with other mineral acids. The Girard reaction greatly improves specificity but does not remove all spurious Zimmermann chromogens. Thin-layer chromatography does not insure complete colorimetric specificity either, and it is found to be a prerequisite for quantitative gas chromatography. GLC using chloromethyldimethyl silyl ethers and 5α-dihydrotestosterone as an internal standard provides excellent separation and quantitation of the 7 individual 17-ketosteroids. Extensive precautions are required with GLC methods (including this one) to find and eliminate contaminants which have the same retention time as steroids of interest; the problem of specificity, so well known with Zimmermann chromogens, is not eliminated by the use of GLC.
A method is described for purification and group separation (11-oxy, 11-deoxy) of the 17-ketosteroids; this is followed by colorimetrie measurement of the groups or, after recombining them, by quantitative GLC analysis to measure the individual steroids.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.