PubMed1993
The aim of the present work was to study the factors that influence the variation of diploid patterns in 75 areas of histologically normal gastric tissue, located in surgically resected stomachs due to early gastric cancer. Each sample was used as a diploid reference of its respective tumoral area. Fifty five samples were embedded in formalin and 20 corresponded to fresh tissue. It was found that in the older tissues, the cellular debris increased, the localization channel of the peaks shifted to the left (lower than channel 60) and the peak shape was deformed, with an increase in the variation coefficient (around 6) and an elevation and lengthening of phase S. When fresh tissue was used, the first peak was localized around channel 60-70, with a significant reduction of cellular debris, a lower variation coefficient amplitude (2-5) and a phase S adhered to the basal line. Aiming to observe the influence of paraffin embedding over time, 21 tissue samples originally assayed as fresh tissues, were reanalyzed one year later. The same alterations initially observed in old tissues were again noticed. According to these results, it is necessary to select adequate controls for flow cytometric analysis to obtain an adequate histogram interpretation, and specially to calculate the ADN index.