| 1. |
- Bergström, Lena, 1973-
(författare)
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Macroalgae in the Baltic Sea : responses to low salinity and nutrient enrichment in Ceramium and Fucus
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The brackish Baltic Sea is a marginal environment for both marine and freshwater species. The rate of ecological differentiation is presumably high due to strong selection pressure from a gradient of decreasing salinity that has been present in its current state for only about 3 000 years. Even more recently, increased nutrient loading due to human activities has affected the growth rate of species, with potential effects on their competitive interactions and responses to other regulating factors. I have investigated the potential effects of low salinity and nutrient enrichment on the distributional ranges of two marine macroalgae with a wide distribution in the Baltic Sea, the red alga Ceramium tenuicorne (Kütz.) Wærn and the brown alga Fucus vesiculosus L. A field study in the northern Baltic Sea indicated a strong relationship between the community structure of macroalgae and abiotic factors even on a small, local scale. The abiotic factors are potentially modulated by eutrophication, which may have a strong effect on the depth distribution and abundance of macroalgae. On a regional scale, laboratory experiments suggested that nutrient enrichment is unlikely to affect the distribution of Ceramium and Fucus along the salinity gradient. Growth in Ceramium from the Baltic Proper was enhanced by nitrate and phosphate, but the response did not override growth constraints due to low salinity. Ceramium from the Gulf of Bothnia had an inherently lower growth rate that was not positively affected by nitrate and phosphate increase. In Fucus vesiculosus, reproductive performance was impaired by nitrate and phosphate levels corresponding to ambient levels in eutrophicated areas of the Baltic Sea, when measured by their effect on zygote attachment, germination, and rhizoid development.The wide distribution of Ceramium in the inner Baltic Sea is probably related to local adaptation, rather than a generalized tolerance of different salinity levels. Ecotypic differences were observed when comparing strains from the Baltic Proper (salinity 7 psu) and the Gulf of Bothnia (4 psu). A high rate of vegetative reproduction was evident, although sexual reproduction was occasionally observed in salinity 4. In Fucus vesiculosus, genetic and morphological analyses of sympatric and allopatric populations of the common, vesicular, morphotype and a dwarf morphotype, characteristic for the Gulf of Bothnia, showed that the dwarf morphotype represents a separate evolutionary lineage. Also, vegetative reproduction was observed in Fucus for the first time, as supported by genetic and experimental data. The results show that the biota of the inner Baltic Sea may have unique adaptive and genetic properties, and that it is highly relevant to consider subspecies diversity in Baltic Sea management.
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| 2. |
- Kautsky, Lena, et al.
(författare)
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Rapid speciation in a newly opened postglacial marine environment, the Baltic Sea
- 2009
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Ingår i: BMC Evolutionary Biology. - : Springer Science and Business Media LLC. - 1471-2148. ; 9:70
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Tidskriftsartikel (refereegranskat)abstract
- Background: Theory predicts that speciation can be quite rapid. Previous examples comprise a wide range of organisms such as sockeye salmon, polyploid hybrid plants, fruit flies and cichlid fishes. However, few studies have shown natural examples of rapid evolution giving rise to new species in marine environments. Results: Using microsatellite markers, we show the evolution of a new species of brown macroalga (Fucus radicans) in the Baltic Sea in the last 400 years, well after the formation of this brackish water body ~8–10 thousand years ago. Sympatric individuals of F. radicans and F. vesiculosus (bladder wrack) show significant reproductive isolation. Fucus radicans, which is endemic to the Baltic, is most closely related to Baltic Sea F. vesiculosus among north Atlantic populations, supporting the hypothesis of a recent divergence. Fucus radicans exhibits considerable clonal reproduction, probably induced by the extreme conditions of the Baltic. This reproductive mode is likely to have facilitated the rapid foundation of the new taxon. Conclusion: This study represents an unparalleled example of rapid speciation in a species-poor open marine ecosystem and highlights the importance of increasing our understanding on the role of these habitats in species formation. This observation also challenges presumptions that rapid speciation takes place only in hybrid plants or in relatively confined geographical places such as postglacial or crater lakes, oceanic islands or rivers.
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| 3. |
- Ahlin, Gustav, et al.
(författare)
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Structural requirements for drug inhibition of the liver specific human organic cation transport protein 1
- 2008
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 51:19, s. 5932-5942
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Tidskriftsartikel (refereegranskat)abstract
- The liver-specific organic cation transport protein (OCT1; SLC22A1) transports several cationic drugs including the antidiabetic drug metformin and the anticancer agents oxaliplatin and imatinib. In this study, we explored the chemical space of registered oral drugs with the aim of studying the inhibition pattern of OCT1 and of developing predictive computational models of OCT1 inhibition. In total, 191 structurally diverse compounds were examined in HEK293-OCT1 cells. The assay identified 47 novel inhibitors and confirmed 15 previously known inhibitors. The enrichment of OCT1 inhibitors was seen in several drug classes including antidepressants. High lipophilicity and a positive net charge were found to be the key physicochemical properties for OCT1 inhibition, whereas a high molecular dipole moment and many hydrogen bonds were negatively correlated to OCT1 inhibition. The data were used to generate OPLS-DA models for OCT1 inhibitors; the final model correctly predicted 82% of the inhibitors and 88% of the noninhibitors of the test set.
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| 4. |
- Alsiö, Johan, et al.
(författare)
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Impact of nandrolone decanoate on gene expression in endocrine systems related to the adverse effects of anabolic androgenic steroids
- 2009
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Ingår i: Basic & Clinical Pharmacology & Toxicology. - : Wiley. - 1742-7835 .- 1742-7843. ; 105:5, s. 307-314
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Tidskriftsartikel (refereegranskat)abstract
- Elite athletes, body builders and adolescents misuse anabolic-androgenic steroids (AAS) in order to increase muscle mass or to enhance physical endurance and braveness. The high doses misused are associated with numerous adverse effects. The purpose of this study was to evaluate the impact of chronic supratherapeutic AAS treatment on circulating hormones and gene expression in peripheral tissues related to such adverse effects. Quantitative real-time PCR was used to measure expression levels of in total 37 genes (including peptide hormones, cell membrane receptors, nuclear receptors, steroid synthesising enzymes and other enzymes) in the pituitary, testes, adrenals, adipose tissue, kidneys and liver of male Sprague-Dawley rats after 14-day administration of the AAS nandrolone decanoate, 3 or 15 mg/kg. Plasma glucose and levels of adrenocorticotropic hormone (ACTH), adiponectin, corticosterone, ghrelin, insulin and leptin were also measured. We found several expected effects on the hypothalamic-pituitary-gonadal axis, while the treatment also caused a number of other not previously identified changes in circulating factors and gene transcription levels such as the dose-dependent reduction of the beta(3)-adrenergic receptor in adipose tissue, reduction of both circulating and mRNA levels of adiponectin, up-regulation of both hydroxymethylglutaryl-CoA-reductase, the rate-limiting enzyme in de novo synthesis of cholesterol, and the receptor for ACTH in the adrenals. The results provide evidence for wide ranging effects of AAS on the hypothalamic-pituitary-adrenal axis, adipose tissue and substrates of the renal control of blood pressure.
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| 5. |
- Bergström, Lena, et al.
(författare)
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Fiskeriundersökning vid Lillgrund : Kontrollprogram för Lillgrunds vindkraftspark
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Regeringen gav 2001 tillstånd till uppförande av en vindkraftpark på Lillgrund i Öresund. Underökningarna i det uppföljningsprogram för eventuella effekter på fisk och fiske som tagits fram, omfattar både en period före anläggandet av vindkraftparken och tre år efter idrifttagandet. Programmets provfisken och datainsamling startade med en baslinjestudie under åren 2002 till 2005. Lillgrunds vindkraftpark, med 48 vindkraftverk, togs i full drift i början av år 2008. I föreliggande rapport presenteras de undersökningar som utförts under parkens första driftsår, samt hur dessa förhåller sig till undersökningsresultaten perioden före vindkraftparkens etablering. Utförandet är integrerat med forskningsprogrammet Vindval som finansieras via Naturvårdsverket. Både bentisk och pelagisk fisk ingår i undersökningarna liksom fiskvandring.
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| 6. |
- Bergström, Lena, et al.
(författare)
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Kustfisk och Fiske : Analyser av tillståndet hos abborre, gädda, gös, piggvar, sik, siklöja och skrubbskädda år 2005
- 2006
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I denna internrapport redovisas de analyser som utgjort underlag till Kustlaboratoriets bidragtill Fiskeriverkets gemensamma resurs- och miljööversikt år 2006. Analyserna häri byggerpå loggboksdata, provfi ske, journalföringsdata, samt i vissa fall även omgivningsdata, ochomfattar abborre, gädda, gös, piggvar, sik, siklöja och skrubbskädda. Syftet har varit attdokumentera analyserna för spridning inom laboratoriet, och de tillhörande texterna är därförkortfattade. Vidare information kan fås av Ann-Britt Florin, Kerstin Söderberg, Lena Bergströmeller Anna Gårdmark, som genomförde analyserna.
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| 7. |
- Bergström, Maria, 1964, et al.
(författare)
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Effect of acidosis on expression of mesothelial cell plasminogen activator inhibitor type-1.
- 2006
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Ingår i: Surgical endoscopy. - : Springer Science and Business Media LLC. - 1432-2218 .- 0930-2794. ; 20:9, s. 1448-52
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Abdominal mesothelial cells are exposed to carbon dioxide during laparoscopy. Previous data indicate that carbon dioxide increases release and expression of plasminogen activator inhibitor type-1 (PAI-1) and induces acidification. METHODS: To assess the impact resulting from a range of pH, human mesothelial cells were exposed to culturing media balanced to pH levels of 6.0 to 8.0 for 90 min. Samples from cell media were withdrawn at several time points. Concentrations of PAI-1 and PAI-1 activity were measured using enzyme-linked immunoassay techniques. To focus on the effect of clinically relevant pH, cells were subjected to pH 6.4 and 7.4. Samples were withdrawn for PAI-1 assessments and for PAI-1 mRNA analyses. RESULTS: During exposure to various levels of pH, PAI-1 secretion and activity were variable. However, 5 h after exposure, greater concentration and activity of PAI-1 were observed in acidified cultures. More PAI-1 mRNA was isolated after exposure of cells to a pH of 6.4, apparently indicating transcriptional regulation. CONCLUSIONS: Mesothelial cells seem to respond to acidification by an increased release and production of PAI-1 in vitro.
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| 8. |
- Bergström, Maria, 1964, et al.
(författare)
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Peritoneal and systemic pH during pneumoperitoneum with CO(2) and helium in a pig model.
- 2008
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Ingår i: Surgical Endoscopy. - : Springer Science and Business Media LLC. - 1432-2218 .- 0930-2794. ; 22:2, s. 359-364
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Local peritoneal effects of laparoscopic gases might be important in peritoneal biology during and after laparoscopic surgery. The most commonly used gas, CO(2), is known to be well tolerated, but also causes changes in acid-base balance. Helium is an alternative gas for laparoscopy. Although safe, it is not widely used. In this study a method for monitoring peritoneal pH during laparoscopy was evaluated and peritoneal pH during CO(2) and helium pneumoperitoneum was studied as well as its systemic reflection in arterial pH. METHODS: For these experiments 20 pigs were used, with ten exposed to pneumoperitoneum with CO(2), and ten to helium. Peritoneal and sub-peritoneal pH were continuously measured before and during gas insufflation, during a 30-minute period with a pneumoperitoneum and during a 30-minute recovery period. Arterial blood-gases were collected immediately before gas insufflation, at its completion, at 30 minutes of pneumoperitoneum and after the recovery period. RESULTS: Peritoneal pH before gas insufflation was in all animals 7.4. An immediate local drop in pH (6.6) occurred in the peritoneum with CO(2) insufflation. During pneumoperitoneum pH declined further, stabilising at 6.4, but was restored after the recovery period (7.3). With helium, tissue pH increased slightly (7.5) during insufflation, followed by a continuous decrease during pneumoperitoneum and recovery, reaching 7.2. Systemic pH decreased significantly with CO(2) insufflation, and increased slightly during helium insufflation. Systemic pH showed co-variation with intra-peritoneal pH at the the end of insufflation and after 30 minutes of pneumoperitoneum. CONCLUSIONS: Insufflation of CO(2) into the peritoneal cavity seemed to result in an immediate decrease in peritoneal pH, a response that might influence biological events. This peritoneal effect also seems to influence systemic acid-base balance, probably due to trans-peritoneal absorption.
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| 9. |
- Birgner, Carolina, et al.
(författare)
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Altered extracellular levels of DOPAC and HVA in the rat nucleus accumbens shell in response to sub-chronic nandrolone administration and a subsequent amphetamine challenge
- 2007
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Ingår i: Neuroscience Letters. - : Elsevier BV. - 0304-3940 .- 1872-7972. ; 412:2, s. 168-172
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Tidskriftsartikel (refereegranskat)abstract
- Associated with acts of violence and polydrug use, abuse of anabolic androgenic steroids (AAS) is an increasing problem in society. The aim of the present study was to elucidate whether sub-chronic treatment with the AAS nandrolone decanoate affects dopamine release and dopamine metabolism in the rat nucleus accumbens shell, before and after an amphetamine challenge. Male Sprague–Dawley rats received daily i.m. injections of nandrolone decanoate (15 mg/kg) or vehicle for 14 days. On day 15, the animals were anaesthetized and a microdialysis probe was implanted into the nucleus accumbens shell. Extracellular fluid was collected 1 h before and 3 h after a single amphetamine injection (5 mg/kg). The samples were then analyzed regarding the content of dopamine, and its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), using HPLC with electrochemical detection. Two weeks of nandrolone decanoate administration caused a significant decrease of the basal DOPAC and HVA levels, which remained low during the first hour following the amphetamine challenge. Dopamine levels did not differ significantly between groups, neither after the nandrolone pre-treatment nor the amphetamine challenge. In conclusion, these novel findings indicate that AAS alter the metabolism of dopamine in a brain region involved in the development of drug dependence.
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| 10. |
- Birgner, Carolina, 1978-
(författare)
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Anabolic androgenic steroids and central monoaminergic systems : Supratherapeutic doses of nandrolone decanoate affect dopamine and serotonin
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Supratherapeutic doses of anabolic androgenic steroids (AASs) are administered, not only as performance-enhancing drugs in the world of sports, but also in order to modify behaviour. AAS abusers are at risk of developing serious physical and psychological side effects such as dependence and aggressive behaviour. The aim of this thesis was to investigate the impact of supratherapeutic doses of nandrolone decanoate after subchronic administration on dopamine and serotonin pathways involved in drug dependence and aggression, in the male rat brain.Adult male Sprague-Dawley rats received intramuscular injections of nandrolone decanoate (3 or 15 mg/kg) or vehicle once daily for 14 days. Nandrolone decanoate pre-exposure abolished the effect of amphetamine on the 3,4-dihydroxyphenylacetic acid (DOPAC) tissue level in the hypothalamus and on the DOPAC/dopamine ratio in the hypothalamus and the hippocampus. A significant decrease of the basal extracellular DOPAC and homovanillic acid (HVA) levels could be detected in the nucleus accumbens, which remained low during the first hour following the amphetamine challenge. Nandrolone decanoate significantly reduced the activity of both monoamine oxidase A and B (MAO-A and -B) in the caudate putamen and amygdala. The gene transcript levels of MAO-B, and the dopamine D1 and D4 receptors were altered in limbic regions. No changes in transcriptional levels could be detected among the serotonin receptor genes examined. However, the density of the serotonin transporter protein was elevated in a range of aggression-related brain regions.Taken together, subchronic administration of nandrolone decanoate causes dopaminergic and serotonergic dysregulations in distinct brain regions. These areas of the brain are involved in the development of drug dependence and expression of impulsive and aggressive behaviours. These results may contribute to explain some of the behavioural changes often reported in AAS abusers, such as polydrug use and impaired impulse control.
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