Organohalogen concentrations and a gross and histologic ...

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150 vailability (Apr-Jul) and low (Aug-Oct) (p>0.11). But there was a larger hepatocytic lipid content for subadults (both micro- and macro-vesiculary) in the bears sampled in Apr-Jul when compared to bears from Aug-Oct (p=0.05). Adult bears from Jan-Jun (but not for Apr-Jul) showed higher frequency of portal fibrosis, when compared to adult bears from Aug-Oct (p0.28), and neither for mononuclear cell infiltrations nor lipid granulomas (both: p>0.25). Relationship between histology and contaminants In the comparison of contaminant levels and histopathological changes, individuals were categorised into three groups (absent, mild and moderate) based on the severity of histological changes (Table 2). ∑-DDTs mean levels differed between pathology groups for adult females (p
Relationship between histology and BMD We measured the bone mineral density (BMD) within groups of histology (absent, mild and moderate) in 44 subadult, adult female and adult male polar bears (Table 3). The sample size for subadults and adult males were too small to evaluate the relationship between histopathological changes and BMD. For adult females, there was no significant difference in BMD levels between groups of mild and moderate histopathological changes. Levels, age relations and the negative correlations between ∑-PCBs, ∑-DDTs, dieldrin and ∑-CHLs, respectively, and skull BMD are reported in Sonne et al., (Accepted with revision). Table 3 Mean (SD) levels of of Bone Mineral Density (BMD; g hydroxyapatite/cm 2 ) in the skull of 44 East Greenland polar bears investigated for liver lesions during 1999-2002. The concentrations are divided on age/sex groups (subadults, adult females and adult males respectively) and liver histological changes based on the results from Table 1. Number of samples are given in paranthesis. “.” indicates missing data. n.s. indicate no statistical significant differences between the three means of the specific age/se s . x group at 5% level. ‡ could not be evaluated due to low sampling size. Histopathology Subadults ‡ Adult females n.s. Adult males ‡ Absent . . 2.2 (1) Mild 1.7±0.4 (19) 1.9±0.1 (10) n.s. 2.3±0.3 (10) Moderate . 2±0.2 (3) n.s. 2.6 (1) Discussion Nuclear dislocation was found in nearly all individuals. Studies by Sato et al., (2001) of polar bears from Svalbard revealed the same, and it was proposed that it could be related to the high vitamin A accumulation (natural storage) in Ito-cells, accumulated through the ”fatty” Arctic marine food chains. In mammalian species, the dislocation is usually associated with hepatitis, carcinomas, hyperplasia (adenomatous) or regeneration (Ibid.). However, in the study by Sato et al., (2001) such histopathological changes were not found. Whether the histological changes in the East Greenland polar bears could be associated to the nuclear dispositioning, could not be evaluated from our study because all individuals exhibited some or all of the histopathological changes. If there was a link between nuclear dislocation and organohalogens or hepatocytic lipid accumulation (e.g. MacLachlan and Cullen 1995) could not be evaluated either. Lipid The Ito-cells are the accumulation and storage site for lipids and vitamin A in polar bears (Leighton et al., 1988, Senoo et al.,1999, 2001). In the present study, fat accumulation (lipids) were found in hepatocytes and Ito-cells (centrolobularily and centroacinary respectively). Polar bears are hyperphagiae from April to July, where they build up their fat deposits (Ramsay and Stirling 1988; Messier et al., 1992). Based on samples from the same polar bears as used in the present study, Dietz et al., (2004) showed a highly seasonal pattern in the lipid-% in adipose tissue, with the lowest levels in spring (Mar-May) during hyperphagia and the highest during Sept. In the present investigation, the seasonal difference in hepatocytic lipid content of subadults (Apr-Jul higher than Aug-Oct) probably reflected the high seal blubber consumption in spring (Ramsay and Stirling 1988; Messier et al., 1992). 151
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National Environmental Research Ins
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National Environmental Research Ins
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Contents Summary 7 Resumé 11 Prefa
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Paper III-b Periodontitis and tooth
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Summary Marine mammals in the Arcti
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elations between histological chang
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Resumé Betydelige mængder svært
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signifikante relationer blev fundet
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Preface Since ca. 1960 signficant a
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Acquarone, Poul Johansen and Inge B
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Abbreviations ∑ Sum of congeners
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Introduction Study area and samplin
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content and composition) varying wi
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Of the PCBs found in the East Green
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son Bay bears while the difference
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Individual levels and biological ef
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No. skulls collected 50 45 40 35 30
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temperature extremes and/or food av
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Chapter 3 Bone mineral density and
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BMD analysed by DXA reflects the ar
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Table 4 Range in the levels (ng/g l
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Chapter 4 Liver histology of East G
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Table 7 Levels of ∑-PCBs, ∑-DDT
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Frequency (%) 100 80 60 40 20 Sever
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Effects of PBBs (PolyBrominated Bip
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Etiology and pathogenesis E Figure
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common sign (Acland 1995, Feldman 1
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Conclusions and final assessments O
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of CYP-450 activity that impact cir
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Regarding renal tissue, we will try
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Bernhoft, A., Ø. Wiig and J. U. Sk
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Feldman, E. C. (1995): Hyperadrenoc
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(eds.): Ringed seals in the North A
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McCormack, K. M., W. M. Kluwe, V. L
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Rosing-Asvid, A., E. W. Born and M.
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Valentino, R., S. Savastano, A. P.
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Paper I Seasonal and temporal trend
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eproductive rates of seals in the B
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concentrations of the 41 individual
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Figure 1 Capture locations of the p
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Table 4 Results of ANOVAs (F-value
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Long-Term Temporal Changes in OC Co
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Discussion Geographical Variation i
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sen et al. (2001) studied the trend
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higher than reported in other studi
Page 91 and 92:
Bergman A, Olsson M. Pathology of b
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Muir D, Norstrom RJ. Geographical d
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Wiig Ø, Gjertz I, Hansson R, Thoma
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Key words: polar bear, Ursus mariti
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2. Materials and methods 2.1 Sampli
Page 101 and 102: 2.3 Age Determination The age deter
Page 103 and 104: No. skulls collected 50 45 40 35 30
Page 105 and 106: Table 4 Results (test and p-values)
Page 107 and 108: Table 6 Results from F-tests (p-val
Page 109 and 110: (oxy-chlordane, trans-chlordane, ci
Page 111 and 112: Also Pertoldi et al. (1997) investi
Page 113 and 114: study could not document a relation
Page 115 and 116: Lie E, Bernhoft A, Riget FF, Beliko
Page 117 and 118: function in harbour seals (Phoca vi
Page 119 and 120: (p=0.94). Negative correlation betw
Page 121 and 122: Osteodensitometry X-ray osteodensit
Page 123 and 124: Figure 2 BMD (g cm 2 ) in skulls fr
Page 125 and 126: Table 3 Significant results from th
Page 127 and 128: 2003) and plasma retinol and thyroi
Page 129 and 130: Comiso JC. 2002. A rapidly declinin
Page 131 and 132: Manalagas SC, Jilka RJ. 1995. Bone
Page 133 and 134: Valentine DW, Soulé M. 1973. Effec
Page 135 and 136: have the potential for adverse heal
Page 137 and 138: Dioxin-like contaminants Extraction
Page 139 and 140: Concentration 9000 8000 7000 6000 5
Page 141 and 142: Acknowledgements Danish Cooperation
Page 143 and 144: Polischuk, S. C., R. J. Letcher, R.
Page 145 and 146: Paper IV Liver histology of free-ra
Page 147 and 148: Histology All tissue samples were t
Page 149 and 150: Figure 1 Hepatic lipid accumulation
Page 151: Figure 2 Left: Portal mononuclear c
Page 155 and 156: kinson 1996). Due to these mechanis
Page 157 and 158: sues. Arctic Monitoring and Assessm
Page 159 and 160: van Duursen, M.B.M., Sanderson, J.
Page 161 and 162: Introduction Polar bears (Ursus mar
Page 163 and 164: Briefly, ∑PCBs is the sum (s) of
Page 165 and 166: Figure 1 Bottom: example of glomeru
Page 167 and 168: Figure 3 Tubular cell proliferation
Page 169 and 170: Hyalin casts Hyalin casts were eval
Page 171 and 172: Figure 6 Hyperemia (arrows) in the
Page 173 and 174: al., 2003). We did not find such a
Page 175 and 176: ANDERSEN, M., E. LIE, A. E. DEROCHE
Page 177 and 178: LUROSS, J. M., M. ALAEE, D. B. SERG
Page 179 and 180: organic mercury in liver and kidney
Page 181 and 182: Introduction Polar bears (Ursus mar
Page 183 and 184: Macroscopic examination of reproduc
Page 185 and 186: Results and discussion The female p
Page 187 and 188: SC II PC/LC Figure 2 The histology
Page 189 and 190: The relatively low levels of analys
Page 191 and 192: (Table 4), and we therefore conclud
Page 193 and 194: Acknowledgements Danish Cooperation
Page 195 and 196: Letcher RJ, Klasson-Wehler E, Bergm
Page 197 and 198: Swart RL, Ross PS, Vedder LJ, Timme
Page 199 and 200: 10. Heier, A., C. Sonne, A. Gröne,
Page 201 and 202: crine organs and skulls in the East
Page 203:
To investigate the relation between
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