Both experiments scored tumors in the same way (24 Swiss roll sections; 150 μm between sections).
We used 10 Swiss roll sections (250 μm apart) for Ptgdr knockout mice and their controls.
Haematoxylin and eosin staining of 'Swiss roll' sections confirmed these differences (see online supplementary figure S10).
For example, we used up to 24 Swiss roll sections for scoring tumors in our first report 5 and in the PTGDS and PPARG experiments shown here.
A reduction in polyp number and size was also evident in methylene blue-stained intestinal segments (figure 1C) and in haematoxylin and eosin-stained 'Swiss roll' sections (figure 1D).
Measurements of crypt depth were taken on micrographs of all well-oriented crypts from H&E-stained "swiss roll" sections of distal colon using ImageJ version 1.38 (National Institutes of Health, Bethesda, MD).
Adenomas were counted histologically at 6 or 14 weeks, without knowing genotypes 5. We used 24 Swiss roll sections spaced 150 μm apart for PTGDS transgenic mice, Pparg knockout mice, and their controls.
We histologically examined >35,000 tumors in Swiss roll sections (Fig. 1A E), including 9837 tumors from 147 mice in Ptgdr knockout experiments, 21,763 tumors from 104 mice in experiments on PTGDS transgenic and Pparg knockout mice, and 3431 tumors reexamined from 39 HPGDS transgenic mice and controls from earlier work 5.
Adventures into the specialty-roll section of the menu, however, turned a bit bumpy.
The experimental research analyses the performance of an old riveted structure, as well as a new equivalent prefabricated hot rolled section, to determine areas which are highly susceptible to fatigue failure.
