| Autor: |
W J, Shih, P S, Bachorik, J A, Haga, G L, Myers, E A, Stein |
| Rok vydání: |
2000 |
| Předmět: |
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| Zdroj: |
Clinical chemistry. 46(3) |
| ISSN: |
0009-9147 |
| Popis: |
We estimated the effects of long-term storage at -70 degrees C on serum total cholesterol, HDL-cholesterol, and triglycerides in specimens that had been stored for up to 7 years. These estimates were made using measurements in serial specimens collected from the placebo control group of the Air Force/Texas Coronary Atherosclerosis Prevention Study over a period of approximately 5 years. We compared the group means for pairs of serial specimens taken at 6- and 12-month intervals, assuming that (a) a negligible placebo effect occurred between the serial specimen pairs; (b) in the absence of storage effects, the variation in the group means would reflect only normal biological variation and would not materially affect the group means for the serial specimens; (c) any systematic changes in these group means would reflect storage-related changes; and (d) storage-related changes are cumulative, i.e., the overall changes for a given storage period are the sum of the changes during previous storage periods. We observed average decreases of 2.0% per year for total cholesterol over 7 years and 2.8% per year in triglycerides for the first 5 years. HDL-cholesterol decreased by 1.3% per year, but this change was not statistically significant. This approach may be useful for estimating storage-related changes for studies in specimens stored for a period of years and for which stability data may not be available. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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