STEREO - A PROGRAM ON A PC-WINDOWS-95 PLATFORM FOR RECORDING AND EVALUATING QUANTITATIVE STEREOLOGIC INVESTIGATIONS OF MULTISTAGE HEPATOCARCINOGENESIS IN RODENTS

The most common organ site of neoplasms induced by carcinogenic chemic als in the rodent bioassay is the liver. The development of cancer in rodent liver is a multistage process involving sequentially the stages of initiation, promotion, and progression. During the stages of promo tion and progression, numerous lesions termed altered hepatic foci (AH F) develop. STEREO was developed for the purpose of efficient and accu rate quantitation of AHF and related lesions in experimental and test rodents. The system utilized is equipped with a microcomputer (IBM-com patible PC running Windows 95) and a Summagraphics MICROGRID or SummaS ketch tablet digitizer. The program records information from digitizat ion of single or serial sections obtained randomly from rat liver tiss ue. With this information and the methods of quantitative stereology, both the number and volume percentage fraction of AHF in liver are cal culated in three dimensions. The recorded data files can be printed gr aphically or in the format of tabular numerical data. The results of s tereologic calculations are stored on floppy disks and can be sorted i nto different categories and analyzed or displayed with the use of sta tistics and graphic functions built into the overall program. Results may also be exported into Microsoft Excel for use at a later time. Any IBM-compatible PC capable of utilizing Windows 95 and MS Office can b e used with STEREO, which offers inexpensive, easily operated software to obtain three-dimensional information from sections of two dimensio ns for the identification and relative potency of initiators, promoter s, and progressors, and for the establishment of information potential ly useful in developing estimations of risk for human cancer. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.