Organohalogen concentrations and a gross and histologic ...

Table 1
Classification of 91 East Greenland polar bears sampled during 1999-2002, into three groups of renal lesions (mild, moderate and
severe) based on glomerular/tubular lesions, hyalin casts, tubular protein droplets and pigments and interstitial changes. Presence of
histopathological changes is given by ”-”: absent, ”(+)”: mild, ”+”: moderate and ”++”: severe.
166
Categorisation
Mild
(n=53)
To test the relationship between histopathological changes, age, sex and
season, all individuals were categorised into one of three groups of severity
(mild, moderate and severe), based on the glomerular, tubular and interstitial
lesions (Table 1). This categorisation was also used in the further datahandling
of histopathological changes in relation to age/sex, season and
contaminants.
Relationships between renal lesions, age and sex
Moderate
(n=27)
Uniform glomerulonephhritis and -sclerosis – + ++
Hyalinisation of tubular basement membrane accompanied with atrophy and fibrosis as well as
total glomerular sclerosis
– + ++
Tubular cellproliferation – – (+)
Medullary cylindric hyaline casts (+) + ++
Tubular protein droplets and pigments + + +
Interstitial mononuclear cell infiltrations (+) (+) (+)
Frequency (%)
100
80
60
40
20
Severe
0
Moderate
Mild
Severe
(n=11)
Fig. 5 shows that no subadults exhibited severe renal lesions, while the
prevalence of mild, moderate and severe lesions, respectively, was the same
in adult females and adult males (p>0.6). This was also reflected in the mean
age of bears with severe lesions, which was significantly higher compared to
bears with mild and moderate lesions, respectively (both: p