Monitoring Human Tissues for Toxic Substances (1991) / Chapter Skim
Currently Skimming:
5. Collection, Short-Term Storage, and Archiving of Tissues
5. Collection, Short-Term Storage, and Archiving of Tissues
Pages 99-110
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 99... ...
The National Health and Nutrition Examination Survey design provides a model for the collection of human tissues and is described in Appendix D A program that monitors environmental chemicals through analysis of chemical concentrations in solid tissues, such as fat or liver, requires a tissue collection network.
|
From page 100... ...
In a national human monitoring program, the selection of institutions to participate in the collection of tissues depends on both the characteristics of the persons from whom tissues are to be collected and the types of tissues needed. For example, if tissues are obtained primarily from accident victims who die very soon after their injury, collection is often restricted to coroners and medical examiners in designated geographic locations.
|
From page 101... ...
Storage freezers that keep temperatures above -80°C and that have a defrost cycle might compromise specimens and chemical analyses (see discussion below) , and freezing and thawing of solid tissue specimens can result in enzyme release into cells and destruction of cell membranes and cell integrity.
|
From page 102... ...
· Banked specimens can be analyzed in parallel with current specimens to provide accurate assessments of the efficacy of regulatory actions. Major banks of human tissues can be found in the Federal Republic of Germany, where blood, liver, and adipose tissue are banked (Kayser, 1982; Lewis et al., 1987)
|
From page 103... ...
Additional uses of the samples might be warranted and could include archiving for future retrospective analyses and development and for validation of analytic methods and use in special studies by other agencies or researchers; choice of sample size should account for such possibilities. ADDITIONAL ISSUES FOR CONSIDERATION The goals of a human-tissue bank, operated in parallel with an environmental monitoring program, should be clear and should be supported with a long-term commitment by the organization sponsoring the program.
|
From page 104... ...
For example, if only adipose tissues were stored and a class of nonlipophilic compounds were identified requiring analysis, valid measurements would be impossible, because the compounds would not concentrate in lipid. The environmental-specimen banking program of the Federal Republic of Germany has elected to analyze and bank three types of human tissue blood, liver, and adipose tissue—and nonhuman specimens to enable chemical analyses of a broad range of contaminants (Lewis et al., 1987~.
|
From page 105... ...
Storage Containers and Specimen Size Storage containers should be chosen to prevent contamination of specimens, be structurally stable, and ensure specimen stability at liquid-nitrogen temperatures. The National Institute of Standards and Technology elected to use Teflon containers for the storage of liver specimens in liquid nitrogen, whereas the special characteristics of blood required that it be collected in one type of container and stored in another (Wise and Zeisler, 1984; Wise and Zeisler, 1985~.
|
From page 106... ...
The availability of archived specimens for extramural projects, as well as potential funding for those projects, should be advertised by EPA. EPA's Scientific Advisory Board or the independent oversight committee that we recommend elsewhere could assist in that role of selecting extramural projects.
|
From page 107... ...
The tissue collection was not originally planned as an archive, but it became an archive because investigators did not want to dispose of remnant tissues that were considered a valuable resource. The archive is currently maintained by the Midwest Research Institute (MRI)
|
From page 108... ...
Specimens collected most recently (1988) had the bright yellow color typical of adipose tissue.
|
From page 109... ...
A primary question is the extent to which these storage artifacts affect specific analyses and compromise the value of the NHATS archive. The effects of storage of specimens at temperatures above -20°C (self-defrosting)
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.