Fig. 2.

High levels of p-SMAD 1/5/9 were detected in the arterioles and adjacent cells in tissue sections from 2 non-uremic calciphylaxis patients. Von Kossa (vK) staining (a, b) and p-SMAD 1/5/9 staining of the corresponding vessel (c, d) are shown. Sectioning of the tissue resulted in artifactual changes in the medial layer of the calcified vessel wall in a; the location of the intimal layer and remaining blood vessel lumen are indicated by a blue, dashed circle. In (c), there is complete loss of the medial and intimal portion of the same vessel. The blue dashed circle indicates the expected location of the blood vessel lumen, corresponding to the adjacent tissue section shown in a. In tissue sections from one patient with calciphylaxis, von Kossa (vK) staining was negative (e, f), while an adjacent section containing the same vessel stained strongly for the presence of p-SMAD 1/5/9 (g, h). Given the size and appearance of the blood vessel, it was unlikely that the absence of calcification was an artifact of sample processing. Black boxes in (a, c, e, g) indicate the magnified regions shown in (b, d, f, h) respectively. Arrows in (d, h) indicate the location of representative p-SMAD 1/5/9-positive cells. Black bars in (a, c, e, g) indicate 100 μm. Black bars in (b, d, f, h) indicate 20 μm.