| 1. |
- Gunnarsson, Peter, 1977-
(författare)
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α1-acid glycoprotein modulates the function of human neutrophils and platelets
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The acute-phase protein α1-acid glycoprotein (AGP; orosomucoid) was initially identified andcharacterised in the 1950s. The normal plasma concentration is around 0.5-1 mg/ml butduring inflammation the concentration increase several fold and the carbohydrate compositionof the protein changes. AGP is a highly glycosylated protein with 45 % of the molecularweight consisting of glycans. These glycans are believed to be of importance for the functionof the protein. However, the precise physiological role of AGP is still unclear.The present thesis reveals that AGP at physiological concentration induce calcium elevationin human neutrophils and platelets. In neutrophils this response was enhanced several fold ifsurface L-selectin was pre-engaged. Our results showed that this L-selectin-mediatedamplification was abolished if the neutrophils were pre-treated with Src or phosphoinositide3-kinase (PI3K) inhibitors. AGP alone did not induce production of reactive oxygen species(ROS) in neutrophils. However, if the neutrophils were activated by the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP) a subsequent addition of AGP caused aprominent ROS response. Moreover, both the calcium rise and the ROS response weredepending on sialic acid residues on AGP. In the case of calcium elevation we defined thereceptor as sialic-acid-binding immunoglobulin-like lectin (Siglec)-5 on the neutrophil.In platelets, AGP induced a Rho-kinase dependent phosphorylation of myosin phosphatasetarget subunit-1 (MYPT1) and a minor calcium response. This resulted in a prominent plateletshape change (i.e. spherical shape and granule centralization) recorded as change in lighttransmission and by differential interference contrast (DIC) microscopy. The shape changecaused by AGP was strongly suppressed by inhibition of Rho-kinase and abolished by Rhokinaseinhibition combined with chelation of intracellular calcium. No other manifestations ofplatelet activation like aggregation or secretion were registered. Opposite to neutrophils theeffect of AGP on platelets was not mediated by an interaction between sialic acid and siglecmolecules. However, the results indicated that AGP may bind to a collagen/thrombospondin-1surface receptor. Endogenous inhibitors like nitric oxide (NO) and adenosine abolished theAGP-induced platelet shape change. The antagonizing action of NO on shape change causedby AGP was long acting. In comparison, other aspects of agonist-induced platelet activation(e.g. intracellular calcium elevations) are only transiently suppressed by NO. This indicatesthat endothelium-derived NO may play a crucial role to counter balance the effect of AGP in vivo.Take together the results in this thesis reveal that AGP can initiate intracellular signalling andmodulate functional responses in neutrophils and platelets.
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| 2. |
- Hirsch, Philipp Emanuel, et al.
(författare)
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An approach to incorporate individual personality in modeling fish dispersal across in-stream barriers
- 2017
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 7:2, s. 720-732
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Tidskriftsartikel (refereegranskat)abstract
- Animal personalities are an important factor that affects the dispersal of animals. In the context of aquatic species, dispersal modeling needs to consider that most freshwater ecosystems are highly fragmented by barriers reducing longitudinal connectivity. Previous research has incorporated such barriers into dispersal models under the neutral assumption that all migrating animals attempt to ascend at all times. Modeling dispersal of animals that do not perform trophic or reproductive migrations will be more realistic if it includes assumptions of which individuals attempt to overcome a barrier. We aimed to introduce personality into predictive modeling of whether a nonmigratory invasive freshwater fish (the round goby, Neogobius melanostomus) will disperse across an in-stream barrier. To that end, we experimentally assayed the personalities of 259 individuals from invasion fronts and established round goby populations. Based on the population differences in boldness, asociability, and activity, we defined a priori thresholds with bolder, more asocial, and more active individuals having a higher likelihood of ascent. We then combined the personality thresholds with swimming speed data from the literature and in situ measurements of flow velocities in the barrier. The resulting binary logistic regression model revealed probabilities of crossing a barrier which depended not only on water flow and fish swimming speed but also on animal personalities. We conclude that risk assessment through predictive dispersal modeling across fragmented landscapes can be advanced by including personality traits as parameters. The inclusion of behavior into modeling the spread of invasive species can help to improve the accuracy of risk assessments.
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| 3. |
- Sundin, Josefin, 1981-, et al.
(författare)
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Behavioural alterations induced by the anxiolytic pollutant oxazepam are reversible after depuration in a freshwater fish
- 2019
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 665, s. 390-399
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Tidskriftsartikel (refereegranskat)abstract
- Anthropogenic pharmaceutical pollutants have been detected in nature across the globe, and recent work has shown negative effects of pharmaceuticals on the health and welfare of many animals. However, whether alterations can be reversed has been poorly investigated, although such studies are essential to assess the effects of high-peak exposure events in waterways where pharmaceutical concentrations are usually low. In this study, we investigated the effects of two concentrations (environmentally relevant 1 μg L−1 and high 100 μg L−1) of oxazepam, an anxiolytic commonly detected in aquatic environments, and whether behavioural alterations are reversible after depuration. Specifically, we measured daytime and night-time swimming activity and daytime behaviours related to boldness (foraging, sheltering and routine swimming activity) using the freshwater burbot (Lota lota). We found that both swimming activity and boldness were affected by oxazepam. Fish exposed to the higher level had a higher burst swimming duration (i.e., fast swimming bouts), both in the daytime and night-time trials. Further, fish exposed to the lower oxazepam level spent less time sheltering than control- and high-level exposed fish, but there was no difference between the control and high oxazepam treatments. For routine swimming activity, quantified in the boldness trials, and for latency to forage, there were no treatment effects. When retesting the fish after depuration, the detected behavioural alterations were no longer present. Since the magnitude of these effects were not consistent across endpoints, our study suggests that oxazepam might not be a great concern for this particular, stress tolerant, species, highlighting the importance of evaluating species-specific effects of pharmaceuticals. The observation that the effects we did find were reversible after depuration is encouraging, and indicates that rapid restoration of behaviours after removal from oxazepam contamination is possible.
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| 4. |
- Swahn, Fredrik, et al.
(författare)
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Endoscopic retrograde cholangiopancreatography with rendezvous cannulation reduces pancreatic injury
- 2013
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Ingår i: World Journal of Gastroenterology. - : Baishideng Publishing Group Inc.. - 1007-9327 .- 2219-2840. ; 19:36, s. 6026-6034
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Tidskriftsartikel (refereegranskat)abstract
- AIM: To examine whether rendezvous endoscopic retrograde cholangiopancreatography (ERCP) is associated with less pancreatic damage, measured as leakage of proenzymes, than conventional ERCP. METHODS: Patients (n = 122) with symptomatic gallstone disease, intact papilla and no ongoing inflammation, were prospectively enrolled in this case-control designed study. Eighty-one patients were subjected to laparoscopic cholecystectomy and if intraoperative cholangiography suggested common bile duct stones (CBDS), rendezvous ERCP was performed intraoperatively (n = 40). Patients with a negative cholangiogram constituted the control group (n = 41). Another 41 patients with CBDS, not subjected to surgery, underwent conventional ERCP. Pancreatic proenzymes, procarboxypeptidase B and trypsinogen-2 levels in plasma, were analysed at 0, 4, 8 and 24 h. The proenzymes were determined in-house with a double-antibody enzyme linked immunosorbent assay. Pancreatic amylase was measured by an enzymatic colourimetric modular analyser with the manufacturer's reagents. All samples were blinded at analysis. RESULTS: Post ERCP pancreatitis (PEP) occurred in 3/41 (7%) of the patients cannulated with conventional ERCP and none in the rendezvous group. Increased serum levels indicating pancreatic leakage were significantly higher in the conventional ERCP group compared with the rendezvous ERCP group regarding pancreatic amylase levels in the 4- and 8-h samples (P = 0.0015; P = 0.03), procarboxypeptidase B in the 4- and 8-h samples (P < 0.0001; P < 0.0001) and trypsinogen-2 in the 24-hour samples (P = 0.03). No differences in these markers were observed in patients treated with rendezvous cannulation technique compared with patients that underwent cholecystectomy alone (control group). Post procedural concentrations of pancreatic amylase and procarboxypeptidase B were significantly correlated with pancreatic duct cannulation and opacification. CONCLUSION: Rendezvous ERCP reduces pancreatic enzyme leakage compared with conventional ERCP cannulation technique. Thus, laparo-endoscopic technique can be recommended with the ambition to minimise the risk for post ERCP pancreatitis. (C) 2013 Baishideng. All rights reserved.
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| 5. |
- Thorlacius, Magnus, et al.
(författare)
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Behavioral dependent dispersal in the invasive round goby Neogobius melanostomus depends on population age
- 2015
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Ingår i: Current Zoology. - 1674-5507. ; 61:3, s. 529-542
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Tidskriftsartikel (refereegranskat)abstract
- Biological invasions cause major ecological and economic costs in invaded habitats. The round goby Neogobius melanostomus is a successful invasive species and a major threat to the biodiversity and ecological function of the Baltic Sea. It is native to the Ponto-Caspian region and has, via ballast water transport of ships, invaded the Gulf of Gdansk in Poland. Since 1990, it has spread as far north as Raahe in Northern Finland (64 degrees 41'04"N, 24 degrees 28'44"E). Over the past decade, consistent individual differences of behavioral expressions have been shown to explain various ecological processes such as dispersal, survival or reproduction. We have previously shown that new and old populations differ in personality trait expression. Individuals in new populations are bolder, less sociable and more active than in old populations. Here we investigate if the behavioral differentiation can be explained by phenotype-dependent dispersal. This was investigated by measuring activity, boldness and sociability of individually marked gobies, and subsequently allowing them to disperse in a system composed of five consecutive tanks connected by tubes. Individual dispersal tendency and distance was measured. Our results revealed that in newly established populations, more active individuals disperse sooner and that latency of a group to disperse depends on the mean sociability of the group. This indicates the presence of personality dependent dispersal in this species and that it is maintained at the invasion front but lost as the populations get older.
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| 6. |
- Thorlacius, Magnus, et al.
(författare)
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Investigating large-scale invasion patterns using-small scale invasion successions-phenotypic differentiation of the invasive round goby (Neogobius melanostomus) at invasion fronts
- 2018
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Ingår i: Limnology and Oceanography. - : Wiley. - 0024-3590 .- 1939-5590. ; 63:2, s. 702-713
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Tidskriftsartikel (refereegranskat)abstract
- Species invasions are an ever-growing problem that increases with globalization through increased frequency of unintentional introductions. Between establishment and spread, a lag phase often occurs in which population growth is exponential and dispersal frequency low. Individual variation in behavioral traits, consistent through time and context, have been found crucial for understanding ecological processes such as density dependent dispersal during species invasions. In a previous study of the invasive round goby (Neogobius melanostomus), we found population differentiation between old and new populations in the Baltic Sea with individuals in new populations being more asocial, bold, and active. Here, we investigate if behavioral differentiations are created already during the initial spread from newly established populations. Hence, we monitored population growth and subsequent small-scale spread (< 800 m) in two newly invaded areas, as well as the behavioral traits previously connected to dispersal, over two successional seasons. We found phenotypic differentiation between dispersing and resident individuals with small-scale dispersers being smaller and more asocial. In addition, our catch-per-unit-effort data suggest a lag-phase of 3-5 yr, following initial colonization, before the round goby start spreading into the surrounding environment. This suggests that, at least in species that grow to high densities fast, sociability is more important than boldness and activity for triggering density-dependent dispersal.
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| 7. |
- Thorlacius, Magnus, 1979-, et al.
(författare)
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Personality differentiation along the invasion succession of the round goby (Neogobius melanostomus) in the Baltic Sea
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Biological invasions, or the movement of species beyond their native range to settle and breed in novel environments, are an ever-growing problem in many parts of the world. A particularly successful invader is the round goby (Neogobius melanostomus), a benthic fish from the Ponto-Caspian region that invaded both the Baltic Sea and the Laurentian Great Lakes in 1990 and has since spread throughout most of Europe’s river systems and into rivers surrounding the Great Lakes. During the past decade, evidence has gathered for the importance of animal personality, or individual specific behavioral traits that display limited plasticity, in the invasion process. Individuals that disperse have been found less social, bolder, more active and to have a greater tendency to explore novel environments. With this study we arethe first to show that round gobies from newly established populations (~4 years) are less social, bolder and more active than those from populations that are older in the invasion succession (>20 years), thereby showing that individuals in newly established populations are not a random sample from the source population. Additionally, all behaviors were correlated indicating a behavioral syndrome in which behavioral adaptation for dispersal (less social, bolder and more active) is dominant in newly established populations.
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| 8. |
- Thorlacius, Magnus, 1979-, et al.
(författare)
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Phenotypic differentiation of Round goby (Neogobius melanostomus) along small-scale invasion succession
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Species invasions are an ever-growing problem that increases with globalization through increased frequency of unintentional introductions. Between establishment and spread, a lag phase often occurs in which population growth is exponential and dispersal frequency low. Individual variation in behavioral traits, consistent through time and context, have been found crucial for understanding ecological processes such as density dependent dispersal during species invasions. In a previous study of the invasive round goby (Neogobius melanostomus), we found population differentiation between old and new populations in the Baltic Sea with individuals in new populations being more asocial, bold and active. Here we investigate if behavioral differentiations are created already during the initial spread from newly established populations. Hence, we monitored population growth and subsequent small-scale spread (< 800 m) in two newlyinvaded areas, as well as the behavioral traits priory connected to dispersal, over two successional seasons. We found phenotypic differentiation between dispersing and resident individuals with small-scale dispersers being smaller and more asocial. In addition, our catch- per-unit-effort data suggest a lag-phase of 3-5 years, following initial colonization, before the round goby start spreading into the surrounding environment. This suggests that, at least in species that grow to high densities fast, sociability is more important than boldness and activity for triggering density-dependent dispersal.
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| 9. |
- Thorlacius, Magnus, 1979-
(författare)
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Round goby invasion of the Baltic Sea : the role of phenotypic variation
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Biological invasions are a major threat to biodiversity world wide with annual economic costs up to 1.4 trillion dollars. The round goby (Neogobius melanostomus) is a particularly fierce invader that threatens ecological function of the Baltic Sea. Individual variation in behavioral traits that remain constant through time and context have been identified as crucial factors for explaining different parts of the invasion process. For example, asocial behavior facilitates dispersal from high density populations and comes with fitness benefits in low conspecific density. The latter is especially relevant, in an invasion context, following the initial colonization of a novel environment when population density usually is low.This thesis investigates the role of individual variation in phenotypic traits on species invasions. The main focus is on the effects of sociability, activity and boldness, but also including aggression and physiological stress tolerance, on dispersal tendency and selection at invasion fronts. To do this, we studied four round goby populations in the Baltic Sea, two of the most recently established and two of the oldest populations.In 2012 we demonstrated that asocial, active and bold round gobies are overrepresented at invasion fronts. Two years later we showed that dispersal from the new populations was led by individuals with high activity levels, while in all populations larger individuals dispersed. We also determined the length of the socalled lag-phase, between colonization and spread, in both newly established populations. The end of the lag-phase is hypothesized being triggered by high population density in the harbors leading to dispersal and subsequen colonization of the surrounding areas by small asocial individuals. In our final experiment, we present evidence of stress coping styles in round gobies, in which more aggressive individuals are also more stress tolerant and vice versa. Though we found no connection between stress coping and population age, we found that mortality was unaffected by population density and that the gobies became more aggressive and stress tolerant when kept in high density.To conclude, we have shown that: 1) individuals with high levels of activity, boldness and asociality are common at invasion fronts; 2) a lag phase occurs between colonization and spread in round goby invasions; 3) asocial individuals drive the spread from high density populations at the invasion front and; 4) round gobies adapt to high densities with high aggression and stress tolerance.
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| 10. |
- Thorlacius, Magnus, 1979-, et al.
(författare)
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Stress coping styles in response to high densities in invasive populations of the round goby (Neogobius melanostomus) in the Baltic Sea
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Over the past decade, individual differences in behavior have gained much interest in the context of species invasions. Certain behavioral traits, such as e.g. aggression, have been suggested to facilitate invasion success and a number of studies have found founding populations at invasion fronts to be a non-random sample of behavioral types from their source populations. In many animals, behavioral and physiological responses to challenge are connected, forming stress coping styles. However, there is a lack of studies considering the role of physiological stress response or coping styles during species invasions. Therefore we investigated the connection between aggression and stress response to high densities, in four invasive round goby (Neogobius melanostomus) populations of different age. We found thefirst evidence for stress coping styles in round gobies, as individuals with a low stress response to high densities are also more aggressive. We did not find an effect of population age, likely because the youngest populations used were already too old, meaning that traits selected for at invasion fronts had started to fade out. Given that individual levels of aggression and stress tolerance are dependent on one another, and aggression has previously been identified as an important facilitator of dispersal and invasion success, stress coping styles should be an important factor during species invasions.
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