Organohalogen concentrations and a gross and histologic ...

Figure 3
Tubular cell proliferation at the
cortico-medullary border of a 7year-old
male East Greenland polar
bear sampled in January 2001
(PAS, 40x). Arrows indicate pigments
in distal convoluted tubules.
Note the pale colour and the polygonal
shape of the cells. Bar: 50
µm.
Figure 4
Intense focal mononuclear cell
infiltration of interstitial renal tissue
of a 3.5-year-old female East
Greenland polar bear sampled in
September 1999. Arrows indicate
atrophic tubule (with macrophages
containing pigments) (PAS, 20x).
Bar: 25 µm.
Interstitial changes
Mononuclear cell infiltrations (lymphocytes, plasma cells and macrophages)
were found in cortex and papilla in 35 individual of varying degrees (Fig. 4),
and was categorised as chronic focal non-suppurative interstitial nephritis.
In 25 of these cases, the infiltrates were located in cortex and/or medulla
and in 10 cases located in the papilla (one 6-year-old male exhibited both
cortical, medullary and papillary interstitial nephritis). In cases of intense
cell infiltrations these were accompanied by tubular atrophy (Fig. 4), but rarely
fibrosis or medullary luminal hyaline casts of protein cylindres.
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