| 1. |
- Berger, Michelle L., et al.
(författare)
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Alternative and legacy flame retardants in marine mammals from three northern ocean regions
- 2023
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Ingår i: Environmental Pollution. - 0269-7491 .- 1873-6424. ; 335, s. 122255-122255
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Tidskriftsartikel (refereegranskat)abstract
- Flame retardants are globally distributed contaminants that have been linked to negative health effects in humans and wildlife. As top predators, marine mammals bioaccumulate flame retardants and other contaminants in their tissues which is one of many human-imposed factors threatening population health. While some flame retardants, such as the polybrominated diphenyl ethers (PBDE), have been banned because of known toxicity and environmental persistence, limited data exist on the presence and distribution of current-use alternative flame retardants in marine mammals from many industrialized and remote regions of the world. Therefore, this study measured 44 legacy and alternative flame retardants in nine marine mammal species from three ocean regions: the Northwest Atlantic, the Arctic, and the Baltic allowing for regional, species, age, body condition, temporal, and tissue comparisons to help understand global patterns. PBDE concentrations were 100–1000 times higher than the alternative brominated flame retardants (altBFRs) and Dechloranes. 2,2′,4,5,5′-pentabromobiphenyl (BB-101) and hexabromobenzene (HBBZ) were the predominant altBFRs, while Dechlorane-602 was the predominant Dechlorane. This manuscript also reports only the second detection of hexachlorocyclopentadienyl-dibromocyclooctane (HCDBCO) in marine mammals. The NW Atlantic had the highest PBDE concentrations followed by the Baltic and Arctic which reflects greater historical use of PBDEs in North America compared to Europe and greater industrialization of North America and Baltic countries compared to the Arctic. Regional patterns for other compounds were more complicated, and there were significant interactions among species, regions, body condition and age class. Lipid-normalized PBDE concentrations in harbor seal liver and blubber were similar, but HBBZ and many Dechloranes had higher concentrations in liver, indicating factors other than lipid dynamics affect the distribution of these compounds. The health implications of contamination by this mixture of compounds are of concern and require further research.
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| 2. |
- Bignert, Anders, et al.
(författare)
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9. Contaminants and Health of Aquatic Wildlife
- 2012. - 1
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Ingår i: Ecology and Animal Health. - Uppsala : Baltic University Press. - 9789186189129 ; , s. 73-85
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Bokkapitel (populärvet., debatt m.m.)
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| 3. |
- Bredhult, Carolina, et al.
(författare)
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Effects of chlorinated biphenyls and metabolites on human uterine myocyte proliferation
- 2007
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Ingår i: Human and Experimental Toxicology. - : SAGE Publications. - 0960-3271 .- 1477-0903. ; 26:10, s. 801-809
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Tidskriftsartikel (refereegranskat)abstract
- Uterine myometrial cells are responsive to sex steroids, which could make them susceptible to actions of endocrine disrupting environmental contaminants such as some PCBs. The aim of this investigation was to identify possible effects of some chlorinated biphenyls (CBs) and their metabolites on myometrial cell proliferation. Myometrial cells obtained from women in both phases of the menstrual cycle and from pregnant women were grown in vitro and exposed to CB 101, CB 118, 3'-MeSO2-CB 101, 4'-MeSO2-CB 101, 4-OH-CB 107, 17 beta-estradiol, progesterone, ethinylestradiol or levonorgestrel. The proliferative activity was studied by a BrdU assay. Myometrial cell cultures originating from pregnant women exhibited decreased proliferation in response to 3'-MeSO2-CB 101, 4'-MeSO2-CB 101 and 4-OH-CB 107. Estradiol, a combination of 1 nM 17 beta-estradiol and 10 nM progesterone, ethinylestradiol and levonorgestrel also reduced the proliferation of the myometrial cells, regardless of whether the cells were collected from either of the menstrual cycle phases or from pregnant women. To our knowledge this study is the first to demonstrate that some CBs affect the proliferative activity of human uterine myocytes.
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| 4. |
- Bredhult, Carolina, 1980-
(författare)
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Effects of some Endocrine Disruptors on Human and Grey Seal Uterine Cells
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The effects of environmental contaminants in humans and animals are of great concern. Some contaminants are endocrine disruptors that may interfere with the endogenous hormonal signalling and disturb, for example, reproductive organs and functions.Primary uterine myometrial cells originating from women and Baltic grey seals were exposed to some polychlorinated biphenyls (PCBs) and their metabolites. Even though human and Baltic grey seal myometrial cells responded differently to the tested PCBs, the results indicate that PCBs can influence myometrial cell proliferation in vitro.The prevalence of uterine leiomyomas was investigated among 257 Baltic grey seals. Leiomyomas were only present in females older than 22 years, at a prevalence of 65%. Proliferation in leiomyoma cells was detected in individuals lacking ovarian proliferation support, suggesting the presence of an exogenous stimulant. By taking into account temporal alterations in the contaminant burden of the seals, PCB exposure was found to be associated with leiomyoma prevalence. In conclusion, PCB exposure may be related to uterine leiomyoma development and proliferation in Baltic grey seals in vivo.Human endometrial endothelial cells (HEECs) were exposed to some endocrine disruptors, and the effects of the endocrine disruptors on cell proliferation and viability were studied. All evaluated endocrine disruptors decreased HEEC proliferation and most also decreased HEEC viability. Further studies revealed that the reduction in HEEC proliferation after exposure to o,p’-DDT was associated with differential expression of mRNA involved in proliferation, defence response, and lipid and cholesterol metabolism compared to untreated HEEC. In conclusion, these studies suggest that endocrine disruptors affect cultured cells from the female reproductive tract of humans and grey seals, and may have deleterious effects on proliferation, viability, and genes involved in defence response, and lipid or cholesterol metabolism.
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| 5. |
- Bredhult, Carolina, et al.
(författare)
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Effects of some endocrine disruptors on the proliferation and viability of human endometrial endothelial cells in vitro
- 2007
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Ingår i: Reproductive Toxicology. - : Elsevier BV. - 0890-6238 .- 1873-1708. ; 23:4, s. 550-559
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Tidskriftsartikel (refereegranskat)abstract
- Endocrine disrupting chemicals (EDCs) pose a potential threat to human reproductive health. We studied the proliferation and viability of human endometrial endothelial cells (HEECs) in vitro after exposure to 2,2-bis(o,p-chlorophenyl)-1,1,1-trichloroethane (o,p′-DDT), 3,3′,4,4′-tetrachlorobiphenyl (CB 77), 3,3′,4,4′,5-pentachlorobiphenyl (CB 126), di-n-butyl phthalate (DBP), bisphenol A (BPA), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and 17β-oestradiol, progesterone, 17α-ethynyl oestradiol and levonorgestrel. Cell proliferation was studied using immunocytochemistry for PCNA expression and a 5-bromo-2′-deoxyuridine assay. Cell viability was studied by vital staining with propidium iodide and Hoechst 33258. HEECs in primary culture responded with increased proliferation to oestradiol and with decreased proliferation to levonorgestrel and the EDCs. Some EDCs also affected cell viability and increased the proportion of necrotic cells. However, the decrease in proliferation in response to DBP and TCDD cannot be explained by cell death. In light of these results, it is possible that the EDCs could have effects in vivo as well as in vitro, and influence processes involving for example endometrial angiogenesis.
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| 6. |
- Bredhult, Carolina, et al.
(författare)
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Study of the relation between the incidence of uterine leiomyomas and the concentrations of PCB and DDT in Baltic gray seals
- 2008
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Ingår i: Reproductive Toxicology. - : Elsevier BV. - 0890-6238 .- 1873-1708. ; 25:2, s. 247-255
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Tidskriftsartikel (refereegranskat)abstract
- Exposure to environmental contaminants is believed to be associated with the previously described decrease in the reproduction rate of Baltic gray seals. In the present study the prevalence of uterine leiomyomas was investigated in 257 Baltic gray seal females examined during 1973-2007, in relation to the levels of polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT) in Baltic biota, using an estimated exposure index. Additionally, the proliferative activity in leiomyomas, occurrence of corpora lutea, and blubber concentrations of PCB and DDT were investigated in a subset of females. Leiomyomas were only found in females 22-41 years old, at a prevalence of 65%. No differences in blubber concentrations of PCB or DDT were detected between the subset of leiomyoma-bearing females and reference females, but the estimated exposure index indicated that the PCB level in Baltic biota might be related to the leiomyoma prevalence in Baltic gray seal females.
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| 7. |
- Britt-Marie, Bäcklin, et al.
(författare)
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Temporal and Geographical Variation of Intestinal Ulcers in Grey Seals (Halichoerus grypus) and Environmental Contaminants in Baltic Biota during Four Decades
- 2021
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Ingår i: Animals. - : MDPI AG. - 2076-2615. ; 11:10, s. 2968-2968
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Tidskriftsartikel (refereegranskat)abstract
- The prevalence of intestinal ulcers and parasites was investigated in 2172 grey seals (Halichoerus grypus) collected in the Baltic Sea and 49 grey seals collected outside the Baltic Sea (i.e., the Atlantic). An increase in frequency of ileocaeco-colonic ulcers was observed in the early 1980s, followed by a decrease in the mid-1990s. At the same time, there was an increase followed by a decrease in brominated flame retardants, Perfluorooctanesulfonic acid (PFOS) and cadmium levels in herring (Clupea harengus), the most common prey item in Baltic grey seal diet, as well as in another top predator in the Baltic, the common guillemot (Uria aalge). The frequency of intestinal ulcers was significantly related to the intensity of acanthocephalan parasites, the age of the seal and the region of the Baltic Sea. Perforation of the intestinal wall was the cause of death in 26 of the investigated Baltic grey seals. In contrast, none of the investigated Atlantic grey seals had intestinal ulcers. They showed a thin colonic wall and very few acanthocephalan parasites. The high prevalence of intestinal ulcers and the high parasite intensity appear to be unique to the Baltic population of grey seals.
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| 8. |
- Bäcklin, Britt-Marie, et al.
(författare)
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2003 års avlysningsjakt på gråsäl
- 2005
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Naturvårdsverket beslutade 2003-04-04 att avlysningsjakt efter gråsäl skulle bedrivas för tredje året i följd. År 2003 års jakt inkluderade åtta län (se Tabell 1) utmed Östersjö-, Bottenhavs- och Bottenvikskusten under perioden 16 april – 31 december. Under perioden den 16/4-31/5 fick högst hälften av respektive läns kvot av sälar fällas. Enligt beslutet fördelades tillstånd för jakt på totalt 170 sälar. Kvoterna fördelades per län enligt en av länsstyrelserna utarbetad modell, som bl.a. bygger på faktorer som antal fiskare, fiskets inriktning, fångstvärde, sälskadornas värde och sälskadornas varaktighet. Naturvårdsverket beslutade även, liksom tidigare år, att fällda sälar skulle få behållas på villkor att prover och ifyllda uppgifter om de fällda sälarna i en s.k. jaktrapport skickades till Naturhistoriska riksmuseet (NRM), Gruppen för Miljögiftsforskning. Nedan redovisas resultat från sammanställningar baserade på patologiska undersökningar, åldersbestämning och uppgifter från jägare samt kustbevakningen. Vissa jämförelser görs även med inskickat materialet från gråsälsjakten år 2002 (Bäcklin, 2003a) och undersökta drunknade eller funna döda gråsälar inskickade till NRM för Naturvårdsverkets nationella övervakningsprogram för toppkonsumenter. Undersökningarna har finansierats av Naturvårdsverkets enheter för Viltförvaltning respektive Miljöövervakning.
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| 9. |
- Bäcklin, Britt-Marie, et al.
(författare)
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2007 års säljakt : Undersökningar av insamlat material
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Naturvårdsverket beslutade 2007-04-11 och 2007-09-21 (Dnr 412-162-07 Nv och 412-6125-07 Nf) att avlysningsjakt efter gråsäl skulle bedrivas för sjunde året i följd under perioden 16 april – 31 december 2007. Jakten inkluderade åtta län (se Tabell 1) utmed Östersjö-, Bottenhavs- och Bottenvikskusten. Under perioden 16/4-31/5 fick högst hälften av respektive läns kvot av sälar fällas. Tillstånd fördelades för jakt på totalt 210 sälar varav Fiskeriverket givits tillstånd att fälla 20 gråsälar i X- och Y-län. Kvoterna fördelades per län enligt en av länsstyrelserna utarbetad modell, som bl.a. bygger på förekomst av gråsäl och faktorer som antal fiskare, fiskets inriktning, fångstvärde, sälskadornas värde samt sälskadornas varaktighet. Naturvårdsverket beslutade även, liksom tidigare år, att fällda sälar skulle få behållas på villkor att prover och ifyllda uppgifter om de fällda sälarna i en s.k. jaktrapport skickades till Naturhistoriska riksmuseet (NRM), Enheten för Miljögiftsforskning. Nedan redovisas resultat från sammanställningar baserade på patologiska under-sökningar, åldersbestämning och uppgifter från jägare samt kustbevakningen. Vissa jämförelser görs även med inskickat material från gråsälsjakten åren 2002-2006 samt med undersökta drunknade/funna döda gråsälar. Undersökningarna har finansierats av Naturvårdsverkets enheter för Viltförvaltning respektive Miljöövervakning.
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| 10. |
- Bäcklin, Britt-Marie, et al.
(författare)
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2010 års gråsälsjakt : Undersökningar av insamlat material
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Naturvårdsverket beslutade 2010-04-12 (Dnr 412-2229-10 Nv ) att skyddsjakt efter gråsäl skulle bedrivas för tionde året i följd. Jakten pågick under perioden 16 april – 31 december och inkluderade nio län (se Tabell 1) utmed Östersjö-, Bottenhavs- och Bottenvikskusten. Under perioden 16/4-30/6 fick högst hälften av respektive läns kvot av sälar fällas. Svenska tillstånd för skyddsjakt omfattade totalt 230 sälar. Kvoterna fördelades per län enligt en av länsstyrelserna utarbetad modell, som bl.a. bygger på förekomst av gråsäl och faktorer som antal fiskare, fiskets inriktning, fångstvärde, sälskadornas värde samt sälskadornas varaktighet. Fälld säl rapporteras av jägaren till kustbevakningen som löpande sammanställer resultaten per län och skickar dessa vidare via e-post enligt sändlista. Naturvårdsverket beslutade även, liksom tidigare år, att fällda sälar skulle få behållas på villkor att prover och ifyllda uppgifter om de fällda sälarna i en s.k. jaktrapport skickades till Naturhistoriska riksmuseet (NRM), Enheten för Miljögiftsforskning.
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| 11. |
- Bäcklin, Britt-Marie, et al.
(författare)
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2010 års knubbsälsjakt Undersökningar av insamlat material
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Naturvårdsverket beslutade 2010-04-28 (Dnr 412-2583-10 Nv ) att skyddsjakt efter knubbsäl skulle bedrivas för andra året i följd. Jakten pågick under perioderna 1/5-31/5 och 1/8-31/12 och inkluderade Västra Götaland och Hallands län (se Tabell 1). Svenska tillstånd för skyddsjakt omfattade totalt 90 knubbsälar. Kvoterna fördelades per län enligt en modell, som bl.a. bygger på förekomst av knubbsäl och faktorer som antal fiskare, fiskets inriktning, fångstvärde, sälskadornas värde samt sälskadornas varaktighet.Fälld säl rapporteras av jägaren till kustbevakningen som löpande sammanställer resultaten per län och skickar dessa vidare via e-post enligt sändlista. Naturvårdsverket beslutade även att fällda sälar skulle få behållas på villkor att prover och ifyllda uppgifter om de fällda sälarna i en s.k. jaktrapport skickades till Naturhistoriska riksmuseet (NRM), Enheten för Miljögiftsforskning.Nedan redovisas resultat från sammanställningar baserade på patologiska under-sökningar, åldersbestämning och uppgifter från jägare samt kustbevakningen.Undersökningarna har finansierats av Naturvårdsverkets enheter för Viltförvaltning respektive Miljöövervakning.Material och metoderI samband med jakten paketerar jägaren inre organ, underkäke, en bit späck med hud samt i förekommande fall penisben i plastpåsar tillsammans med jaktrapporten. Påsen fryses och skickas till utsett uppsamlingsställe eller direkt till NRM. På NRM har påsarna tinats och innehållet undersökts makroskopiskt. Vikt bestäms på hjärta, lever, binjurar och gonader. Provtagning för bakteriologisk eller parasitologisk undersökning utförs vid misstanke om infektion. Dessa undersökningar utförs i förekommande fall av Statens Veterinärmedicinska Anstalt (SVA) i Uppsala. Underkäkar kokas och tänder tas ut för snittning och åldersbestämning. För kvalitetssäkrad åldersbestämning har en oberoende avläsning gjorts vid minst två tillfällen per säl. Mag- och tarminnehåll har tillvaratagits för dietstudier. För framtida analyser har vävnadsprover och ben tagits till miljöprovbanken.Mikroskopisk undersökning av vävnader har ej utförts eftersom materialet ofta varit kadaveröst förändrat samt fryst. Frysning av vävnaden medför vissa skador på cellnivå. I den följande redovisningen varierar antal undersökta sälar, beroende på att organ saknats i vissa påsar och/eller att jaktrapporter varit ofullständigt ifyllda.Graden av sjukliga förändringar i organen har bedömts i fyra steg från -utan synlig sjuklig förändring, lindrig, måttlig, till - kraftig förändring. 3För bedömning och förekomst av tarmsår, som förekommer hos gråsäl i Östersjön (Bergman, 1999), har bakre delen avileum samt caecum och colon (tunntarmen nära blindtarmen, blindtarmen och grovtarmen) från varje säl samlats för jämförande bedömning vid samma tillfälle.Späcktjockleken (hullet) baseras på av jägaren ifylld uppgift i jaktrapporten. Somgott hull räknades en späcktjocklek överstigande 35 mm, medelgott hull 26-35 mm och mindre gott hull understigande 26 mm.Knubbsälshonor har räknats som könsmogna när en gulkropp (corpus luteum) har observerats i äggstockarna.
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| 12. |
- Bäcklin, Britt-Marie, et al.
(författare)
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Proliferative Effects of Estradiol, Progesterone, and Two CB Congeners and Their Metabolites on Gray Seal (Halichoerus grypus) Uterine Myocytes in Vitro
- 2003
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Ingår i: Toxicological Sciences. - : Oxford University Press (OUP). - 1096-6080 .- 1096-0929. ; 75:1, s. 154-160
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Tidskriftsartikel (refereegranskat)abstract
- Gray seal females living in the Baltic Sea have been found to exhibit a high prevalence of uterine leiomyomas. These animals are also known to accumulate lipid-soluble PCBs in their blubber. PCBs have documented endocrine-disrupting effects; to investigate whether the PCBs could be part of the genesis of uterine smooth muscle tumors in this species, gray seal myometrial cell cultures were exposed to two CBs and their metabolites, as well as to estradiol and progesterone, after which the effects were analyzed in terms of proliferative activity by measurements of BrdU absorbance and protein content. Progesterone was found to have an inhibitory effect, whereas one CB acted as a stimulant on the myometrial cell proliferation. One of the CB metabolites also seemed to have an inhibitory effect, although this could not be statistically verified. These results suggest that some CBs have effects on uterine myometrial cell proliferation in gray seals and, thus, may also take part in the growth regulation of uterine leiomyomas.
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| 13. |
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| 14. |
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| 15. |
- Bäcklin, Britt-Marie, 1957-, et al.
(författare)
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Sälpopulationer och sälhälsa
- 2016
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Ingår i: HAVET 2015/2016. - : Havsmiljöinstitutet. - 9789198229134 - 9789187967122 ; , s. 116-118
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 16. |
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| 17. |
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| 18. |
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| 19. |
- Härkönen, Tero, et al.
(författare)
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Sälpopulationer och sälhälsa
- 2014
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Ingår i: Havet. - Göteborg : Havsmiljöinstitutet. - 1654-6741. ; , s. 93-94
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 20. |
- Lind, Ylva, 1954-, et al.
(författare)
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Stability of fatty acid composition in seal blubber during long-term storage
- 2012
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Ingår i: Marine Ecology Progress Series. - : Inter-Research Science Center. - 0171-8630 .- 1616-1599. ; 461, s. 283-291
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Tidskriftsartikel (refereegranskat)abstract
- This study was performed to evaluate the stability of the fatty acid (FA) composition of blubber from Baltic grey seals Halichoerus grypus archived at −25°C in the Swedish Environmental Specimen Bank (SESB). Possible alterations of FA compositions with storage time and temperature were evaluated. Blubber from 5 seals was kept at +2°C and at −20°C and sampled for up to 6 mo and 33 mo, respectively. Furthermore, FA profile stability was evaluated in blubber stored in the SESB for 4 and 6 yr. This was done by re-sampling and re-analyzing blubber samples from SESB. In both parts of the study, a principal component analysis was performed on 48 FAs comprising 98 to 99% of the total FAs in blubber of Baltic grey seals. We found no indication of a critically altered FA composition, neither in blubber stored at +2°C for 6 mo nor in blubber stored at −20°C for 33 mo. The re-analysis of samples stored in SESB for ~4 to 6 yr only differed for a few FAs in some samples. The most remarkable differences were a slight increase in some long-chain unsaturated FAs (18:2n-6, 20:3n-3, 20:4n-3, 22:4n-3). As an increase in long-chain polyunsaturated FAs due to storage is highly unlikely, we believe that this is probably more due to the sampling technique than to a critically altered FA composition due to storage. Our results suggest that archived seal blubber may be safely used in retrospective analyses of diet using an FA signature analysis technique.
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| 21. |
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| 22. |
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| 23. |
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| 24. |
- Neimane, Aleksija, et al.
(författare)
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Emergence of the Zoonotic Biliary Trematode Pseudamphistomum truncatum in Grey Seals (Halichoerus grypus) in the Baltic Sea
- 2016
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:10, s. e0164782-
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Tidskriftsartikel (refereegranskat)abstract
- The biliary trematode Pseudamphistomum truncatum parasitizes a wide range of fish-eating mammals, including humans. Here we report the emergence of this parasite in grey seals (Halichoerus grypus) in the Baltic Sea. One hundred eighty-three of 1 554 grey seals (11.9%) examined from 2002–2013 had detectable hepatobiliary trematode infection. Parasite identification was confirmed as P. truncatum by sequencing the ITS2 region of a pool of five to 10 trematodes from each of ten seals collected off the coast of seven different Swedish counties. The proportion of seals parasitized by P. truncatum increased significantly over time and with increasing age of seals. Males were 3.1 times more likely to be parasitized than females and animals killed in fishery interactions were less likely to be parasitized than animals found dead or hunted. There was no significant difference in parasitism of seals examined from the Gulf of Bothnia versus those examined from the Baltic Proper. Although the majority of infections were mild, P. truncatum can cause severe hepatobiliary disease and resulted in liver failure in at least one seal. Because cyprinid fish are the second intermediate host for opisthorchiid trematodes, diets of grey seals from the Baltic Sea were analysed regarding presence of cyprinids. The proportion of gastrointestinal tracts containing cyprinid remains was ten times higher in seals examined from 2008 to 2013 (12.2%) than those examined from 2002 to 2007 (1.2%) and coincided with a general increase of trematode parasitism in the host population. The emergence and relatively common occurrence of P. truncatum in grey seals signals the presence of this parasite in the Baltic Sea ecosystem and demonstrates how aquatic mammals can serve as excellent sentinels of marine ecosystem change. Investigation of drivers behind P. truncatum emergence and infection risk for other mammals, including humans, is highly warranted.
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| 25. |
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| 26. |
- Nordlund, Jessica, et al.
(författare)
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Genome-wide signatures of differential DNA methylation in pediatric acute lymphoblastic leukemia
- 2013
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Ingår i: Genome Biology. - : Springer Science and Business Media LLC. - 1465-6906 .- 1474-760X. ; 14:9, s. r105-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:Although aberrant DNA methylation has been observed previously in acute lymphoblastic leukemia (ALL), the patterns of differential methylation have not been comprehensively determined in all subtypes of ALL on a genome-wide scale. The relationship between DNA methylation, cytogenetic background, drug resistance and relapse in ALL is poorly understood.RESULTS:We surveyed the DNA methylation levels of 435,941 CpG sites in samples from 764 children at diagnosis of ALL and from 27 children at relapse. This survey uncovered four characteristic methylation signatures. First, compared with control blood cells, the methylomes of ALL cells shared 9,406 predominantly hypermethylated CpG sites, independent of cytogenetic background. Second, each cytogenetic subtype of ALL displayed a unique set of hyper- and hypomethylated CpG sites. The CpG sites that constituted these two signatures differed in their functional genomic enrichment to regions with marks of active or repressed chromatin. Third, we identified subtype-specific differential methylation in promoter and enhancer regions that were strongly correlated with gene expression. Fourth, a set of 6,612 CpG sites was predominantly hypermethylated in ALL cells at relapse, compared with matched samples at diagnosis. Analysis of relapse-free survival identified CpG sites with subtype-specific differential methylation that divided the patients into different risk groups, depending on their methylation status.CONCLUSIONS:Our results suggest an important biological role for DNA methylation in the differences between ALL subtypes and in their clinical outcome after treatment.
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| 27. |
- Persson, Sara, et al.
(författare)
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Influence of age, nutritional status and season on the reproductive system in wild male mink (Neovison vison)
- 2011
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Ingår i: European Journal of Wildlife Research. - : Springer Science and Business Media LLC. - 1612-4642 .- 1439-0574. ; 57:5, s. 1057-1063
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Tidskriftsartikel (refereegranskat)abstract
- The objectives of this study on the reproductive system of wild male mink (Neovison vison) were to determine the influence of age, nutritional status and season on reproductive traits and to produce baseline data that may be used in environmental monitoring programmes. The 117 male mink included in the study were killed by hunters all over Sweden (from latitude 56 degrees N to 67 degrees N) during August to the end of April from 2005 to 2008. The weights of penis, testes, and epididymides were lower, the anogenital distance was shorter and the diameter of seminiferous tubules was less in juveniles compared with adult mink (p<0.0001-p=0.0024). There was a positive effect (p<0.05) of nutritional status on the baculum length and on the anogenital distance, but not on any of the other reproductive traits. The season of sampling influenced the penis, testes and epididymes weights and the diameter of seminiferous tubules (p=0.008-p<0.0001). During spring, 86% of the mink had sperm in their epididymides, whereas the corresponding figure for autumn was 3%; in addition, when the average diameter of the tubules reached 138 mu m, sperm were present in the epididymides. Sperm morphology was analysed in 29 of the mink, and the percentage of morphologically defect sperm were generally low. Taken together, this study suggests that when assessing male reproductive data in wild mink populations, season must be taken into account as well as whether the individuals are juvenile or adult. In contrast, the nutritional status seems not to be of any major significance.
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| 28. |
- Persson, Sara, et al.
(författare)
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Influence of age, season, body condition and geographical area on concentrations of chlorinated and brominated contaminants in wild mink (Neovison vison) in Sweden
- 2013
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Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 90:5, s. 1664-1671
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Tidskriftsartikel (refereegranskat)abstract
- The wild mink has gained acceptance as a sentinel species in environmental monitoring. However, only limited data are available in the literature on factors driving variability in concentrations of organic pollutants in this species. This study characterizes the differences in contaminant concentrations in subcutaneous fat of male mink from four different areas in Sweden and demonstrates how age, season and body condition influence concentrations of polychlorinated biphenyl (PCB) congeners, polybrominated diphenyl ether (PBDE) congeners (including methoxylated forms, MeO-PBDEs), as well as the pesticides dichlorodiphenyldichloroethylene (DDE), chlordane and hexachlorobenzene (HCB). The data were statistically treated using multiple regression and principal component analysis. The Sigma PCB concentration and concentrations of PCB congeners 138, 156, 157, 180,170/190, 189, 194, 206, 209 as well as PBDE 153/154 varied with age. Season had an influence on Sigma PCB, PBDE 47 and PBDE 153/154 concentrations, as well as concentrations of most PCB congeners, with the exception of PCB 101, 110, 141 and 182/187. Lean mink had higher concentrations of most PCBs and PBDEs than mink with larger fat depots. The analyzed pesticides (DDE, oxychlordane, HCB) showed no systematic variation with season, age or body condition. The concentrations of MeO-PBDEs were generally low and 6Me-PBDEO 47 was the most commonly detected MeO-PBDE in mink from marine, brackish and freshwater areas. The results indicate that age, season and body condition are factors that may influence the concentrations of PCBs and PBDEs, and it is thus recommended to take these factors into account when analyzing mink exposure data.
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| 29. |
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| 30. |
- Persson, Sara, et al.
(författare)
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Wild mink (Neovison vison) as sentinels in environmental monitoring
- 2012
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Ingår i: Acta Veterinaria Scandinavica. - 0044-605X .- 1751-0147. ; 54:Suppl1, s. S9-
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Tidskriftsartikel (refereegranskat)abstract
- For monitoring of endocrine disruptors and other contaminants in terms of exposure levels and possible effects on the reproductive system, suitable sentinel species have to be used. The wild mink is putatively a good sentinel, as it is a semi-aquatic top predator present in all parts of Sweden and it is hunted extensively. When studying the wild mink from an environmental health perspective, one has to consider advantages and disadvantages with different ways of sampling. Field studies often generate large data sets and the variables measured may show large variation due to intrinsic and extrinsic biological factors; this must be adjusted for when analyzing data in order to increase the chances of identifying associations between exposure and health effects. With focus on our own data from studies in wild mink in Sweden, this article describes how the mink can be used in large scale screening of exposure and effects of contaminants.
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| 31. |
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| 32. |
- Roos, Anna, et al.
(författare)
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POPs, PFAS and metals in ringed seals (Pusa hispida botnica) from the Baltic 1978-2015
- 2019
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Twenty two pooled samples from 69 juvenile ringed seals collected between 1974 and 2015 were analyzed for PCB (22 congeners), pesticides, PFAS, metals and selenium. Most seals were bycaught in fishing gear. All CB congeners were above the detection limits. CB-138 and -153 accounted for ca 50% of ∑PCB. CB-180 and -101 stood for ca 10 % each. ∑PCB decreased over the study period with approximately -4.6% annually and since 2000 the mean concentrations (i.e. in pooled samples) were below 9 mg/kg in these juvenile seals, which is the lowest suggested threshold for onset of physiological effects in experimental marine mammal studies.sDDT decreased with a rate of ca -8.9% yearly. The proportion of p,p’DDE increased over time as p,p’DDT decreased. Chlordanes and nonachlor also decreased over time (-4.6%). Trans-nonachlor was the most predominating compound. Finally, mirex decreased over time at a rate of approximately -2.3% annually. Nine PBDE congeners were analyzed in blubber. The predominating BDE was BDE-47 (ca 70%) followed by BDE-99 and BDE-100. Most BDE congeners peaked during the 1990s. Eleven perfluorinated substances were analysed. PFHxA and PFHpA were below detection limits in all but three samples not included in the statistical analyses. All but FOSA showed increasing trends over the study period, with increasing rates of +5-9% annually. However, if only looking at the last 15 years the concentrations appear stable (i.e. not increasing or decreasing). FOSA showed decreasing rates over the full period as well as the last 15 years. PFOS was observed in the highest concentrations (range 9.4-400 ng/g ww) and was the predominant PFAS. PFNA was the predominant PFCA followed by PFDA and PFUnDA. Arsenic (As), cadmium (Cd), cobalt (Co), copper (Cu), (Cr), mercury (Hg), manganese (Mn), nickel (Ni), selenium (Se) and zinc (Zn) were analysed in seal liver. Cr was below detection limit in all samples but one, which was at detection limit. Ni was below detection limit in all samples. Only Co showed slight decreasing concentrations, the concentrations of the other metals were stable over time. However, concentrations of Pb were very low, and after 2000 below detection limit (<0.03 mg/kg ww), indicating decreasing concentrations. The relationship Hg vs Se on a molar basis showed no trend over time. Generally, the ratio was slightly below 1, but in five samples it did exceeded 1 (mean ratio was 0.9).
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| 33. |
- Silva, William, et al.
(författare)
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Life cycle bioenergetics of the gray seal (Halichoerus grypus) in the Baltic Sea: Population response to environmental stress
- 2020
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Ingår i: Environment International. - : Elsevier. - 0160-4120 .- 1873-6750. ; 145
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Tidskriftsartikel (refereegranskat)abstract
- Wildlife population dynamics are shaped by multiple natural and anthropogenic factors, including predation, competition, stressful life history events, and external environmental stressors such as diseases and pollution. Marine mammals such as gray seals rely on extensive blubber layers for insulation and energy storage, making this tissue critical for survival and reproduction. This lipid rich blubber layer also accumulates hazardous fat soluble pollutants, such as polychlorinated biphenyls (PCBs), that can directly impact adipose function or be mobilized during periods of negative energy balance or transferred to offspring to exert further impacts on target tissues or vulnerable life stages. To predict how marine mammals will respond to ecological and anthropogenic stressors, it is necessary to use process-based modelling approaches that integrate environmental inputs, full species life history, and stressor impacts with individual dynamics of energy intake, storage, and utilization. The purpose of this study was to develop a full lifecycle dynamic energy budget and individual based model (DEB-IBM) that captured Baltic gray seal physiology and life history, and showcase potential applications of the model to predict population responses to select stressors known to threaten gray seals and other marine mammals around the world. We explore variations of three ecologically important stressors using phenomenological simulations: food limitation, endocrine disrupting chemicals that reduce fertility, and infectious disease. Using our calibrated DEB-IBM for Baltic gray seals, we found that continuous incremental food limitation can be more detrimental to population size than short random events of starvation, and further, that the effect of endocrine disruptors on population growth and structure is delayed due to bioaccumulation, and that communicable diseases significantly decrease population growth even when spillover events are relatively less frequent. One important finding is the delayed effect on population growth rate from some stressors, several years after the exposure period, resulting from a decline in somatic growth, increased age at maturation and decreased fecundity. Such delayed responses are ignored in current models of population viability and can be important in the correct assessment of population extinction risks. The model presented here provides a test bed on which effects of new hazardous substances and different scenarios of future environmental change affecting food availability and/or seal energetic demands can be investigated. Thus, the framework provides a tool for better understanding how diverse environmental stressors affect marine mammal populations and can be used to guide scientifically based management.
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| 34. |
- Sun, Jiachen, et al.
(författare)
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Hepatic Fatty Acid Profiles Associated with Exposure to Emerging and Legacy Halogenated Contaminants in Two Harbor Seal Populations across the North Atlantic
- 2022
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 1086-931X .- 1520-6912 .- 0013-936X .- 1520-5851. ; 56:3, s. 1830-1840
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Tidskriftsartikel (refereegranskat)abstract
- Fatty acids (FAs) have been extensively used as indicators of foraging ecology in marine mammals, yet their association with exposure to contaminants has rarely been investigated. The present study provided the first characterization of the relationship between hepatic FA profiles and exposure to a suite of contaminants in a sentinel species─the harbor seal (Phoca vitulina)─from the Gulf of Maine and the south coast of Sweden. FA profiles differed in the two seal populations, and the levels of legacy and alternative brominated flame retardants and polyhalogenated carbazoles were significantly elevated in Maine seals. Correlations between individual FAs and multiple flame retardants (FRs) and poly- and perfluoroalkyl substances (PFASs) were found in seals from both populations. Moreover, several FR and PFAS chemicals were significantly associated with the estimated desaturating enzyme activity inferred from the FA profiles. The ratios of poly to monounsaturated FAs (∑PUFAs/∑MUFAs) and those of unsaturated to saturated FAs (∑UFAs/∑SFAs) were significantly associated with HBBZ, PFHxS, or BDE 47 in seals from Maine and Sweden, whereas ∑n – 6/∑n – 3 PUFAs was significantly associated with BDE 154 and 36-CCZ in Swedish and Maine seals, respectively. Our results suggest the lipid metabolism-disrupting potential of these contaminants in marine mammals and warrant continuous biomonitoring and risk assessment, considering the critical role of PUFAs in vital biological processes.
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| 35. |
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