Organohalogen concentrations and a gross and histologic ...

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Skull BMD and histology
The relationship between BMD and histology was tested for subadults, adult
females and adult males, respectively. The model was a ANCOVA with
BMD (bone mineral density) as dependent variable, age as covariable variable,
histology as class variable and their 1 st
order interaction links (age*
histology). The model reduction and identification of significant factors were
similar to those described in the previous section.
Results
Kidney
The kidney histology of the 91 polar bears (50 subadults, 22 adult females
and 19 adult males) collected from 1999 to 2002, were multilobulated similar
to e.g. domestic cow (Bos taurus) and ringed seal (Phoca hispida) (e.g. Dragert
et al., 1975; Habel, 1992, Sonne-Hansen et al., 2002) and the histology of each
functional unit (lobule) appeared to be similar to marine mammal renal tissue
in general (Ibid.). It was not possible to investigate the entire kidney
macroscopically during the hunt and sampling.
Glomerular lesions
Moderate and severe uniform glomerulonephritis and –sclerosis was found
in 38 of the 91 examinated East Greenland polar bears (Fig. 1). When these
lesions were present, PAS-positive (hyalinisation) increase of the mesangial
matrix was found (Fig. 1). In the examination of the basement membranes by
PAS-M silverstaining, no humps (segmental thickening) were present but we
could detect obvious mesangial cell-proliferations, but no proliferations of the
glomerular endothelial cells, while occasionally proliferation of visceral
epithelial cells of Bowman’s capsule was found. In few cases small glomerular
unifocal hyalin nodules were found as well as segmental capsular adhesions
between glomerular basement membranes and Bowman’s capsule with luminal
PAS-positive hyalin depositioning of Bowman’s space. Dense PASpositive
total hyalinisation (sclerosis) of the glomeruli was found in the most
severe cases of glomerulonephritis – and sclerosis and tubular atrophy and fibrosis
(Fig. 2).