Marked changes in the C3H/HeN CLP mouse Peyer's patch histology are evident at both the light microscopic (A v B) level and at the electron microscopic level (C v D) 24 hours postsham or CLP. (A) Illustrates typical lymphocyte morphology. The figure is oriented with the mucosal epithelia (Mu) appearing on the right side of the picture moving towards the germinal center on the left-hand side (magnification = 216X). (C) Shows normal lymphocytic morphology encountered at an electron microscopic level in the sham mouse's Peyer's patch (magnification = 4825X). (B) Alternatively, shows changes typically encounter in the Peyer's patch of a septic mouse at a light microscopic level. Clusters of apoptotic cells (Apo), with condense nuclei, can be observed, appearing to increase in frequency within the germinal center of the CLP mouse's Peyer's patch, as opposed to the T-cell zone adjacent to the mucosal epithelia (Mu)(magnification = 216X). (D) Electron microscopic inspection of a typically cluster of apoptotic cells within the germinal center showed marked nuclear condensation (CN), cytoplasmic shrinkage, as well as evidence of apoptotic fragmentation (Apo)(magnification = 4825X).