Next steps in the validation of the pubertal assays Issues, questions, plans J. Kariya OSCP/USEPA December 11, 2003 Initial questions for EDMVS
Issues, questions, plans
December 11, 2003
To determine whether independent laboratories arrive at the same, correct conclusion about the ability of an unknown chemical to interact with the endocrine system when using the pubertal assays, in the absence of other information about the chemical.
To refine the protocol, if necessary, by identifying specific areas of difficulty in performing the assay.
The Parts will be done in parallel, to expedite EDSP and to avoid interference with the test of transferability.
* beyond what is already in the Critical Reviews in Tox protocol
Letters denote codes for chemicals. G and H are identical chemical but coded differently.
1. T4 and TSH will be required endpoints.
2. Thyroid fixative, weighing, and histology to be specified.
3. Removal of LABC complex for weighing to be described.
4. Standardized definitions of estrus stages and “irregular cycling” to be provided.
5. Identification and treatment of outliers to be specified. (continued)
6. Method for calculating mean and variances for day of VO/PPS when some animals have not reached this endpoint by the time of sacrifice to be included.
7. (dose volume to be specified?)
8. (dose setting procedure?)
9. Reporting format to be specified.
Note: last set of data took over a year to go from Work Assignment to EDMVS, without searching for subcontractors, without GLP, without dose-setting, and with a smaller number of labs to compare.
Not compatible with time frame