| 1. |
- Agyemang, Alex Adusei, et al.
(författare)
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Cell-free oxidized hemoglobin drives reactive oxygen species production and pro-inflammation in an immature primary rat mixed glial cell culture
- 2021
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Ingår i: Journal of Neuroinflammation. - : Springer Science and Business Media LLC. - 1742-2094. ; 18:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Germinal matrix intraventricular hemorrhage (GM-IVH) is associated with deposition of redox active cell-free hemoglobin (Hb), derived from hemorrhagic cerebrospinal fluid (CSF), in the cerebrum and cerebellum. In a recent study, using a preterm rabbit pup model of IVH, intraventricularly administered haptoglobin (Hp), a cell-free Hb scavenger, partially reversed the damaging effects observed following IVH. Together, this suggests that cell-free Hb is central in the pathophysiology of the injury to the immature brain following GM-IVH. An increased understanding of the causal pathways and metabolites involved in eliciting the damaging response following hemorrhage is essential for the continued development and implementation of neuroprotective treatments of GM-IVH in preterm infant.METHODS: We exposed immature primary rat mixed glial cells to hemorrhagic CSF obtained from preterm human infants with IVH (containing a mixture of Hb-metabolites) or to a range of pure Hb-metabolites, incl. oxidized Hb (mainly metHb with iron in Fe3+), oxyHb (mainly Fe2+), or low equivalents of heme, with or without co-administration with human Hp (a mixture of isotype 2-2/2-1). Following exposure, cellular response, reactive oxygen species (ROS) generation, secretion and expression of pro-inflammatory cytokines and oxidative markers were evaluated.RESULTS: Exposure of the glial cells to hemorrhagic CSF as well as oxidized Hb, but not oxyHb, resulted in a significantly increased rate of ROS production that positively correlated with the rate of production of pro-inflammatory and oxidative markers. Congruently, exposure to oxidized Hb caused a disintegration of the polygonal cytoskeletal structure of the glial cells in addition to upregulation of F-actin proteins in microglial cells. Co-administration of Hp partially reversed the damaging response of hemorrhagic CSF and oxidized Hb.CONCLUSION: Exposure of mixed glial cells to oxidized Hb initiates a pro-inflammatory and oxidative response with cytoskeletal disintegration. Early administration of Hp, aiming to minimize the spontaneous autoxidation of cell-free oxyHb and liberation of heme, may provide a therapeutic benefit in preterm infant with GM-IVH.
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| 2. |
- Dalby, Lars, et al.
(författare)
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The status of the Nordic populations of the Mallard (Anas platyrhynchos) in a changing world
- 2013
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Ingår i: Ornis Fennica. - : Finnish Omithological Soc. - 0030-5685. ; 90:1, s. 2-15
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Tidskriftsartikel (refereegranskat)abstract
- Dabbling ducks (Anas spp.) are importantmigratory quarry species, protected as a shared resource under international legislation. However, there is a lack of sufficient high-quality data on vital demographic rates and long-term trends in numbers to judge the conservation status of many duck populations at the flyway level. In response to reported declines in the North-West European flyway population of theMallard, we compiled available data on this species in the Nordic countries up to 2010. Generally, national breeding numbers showed increasing trends, wintering abundance showed variable trends, and productivitymeasures indicated stable or increasing trends.Major knowledge gaps were identified, namely the size of hunting bags, the influence of the released Mallards and the role of short-stopping in explaining changing patterns of wintering abundance across the North-West European flyway. Numerically the Nordic breeding population appears in “good condition”, and the wintering numbers have been either stable or increasing in the last two decades. The annual number of releases needs to be determined in order to judge the sustainability of the current levels of exploitation. Overall, none of the indicators showed alarming signs for the Mallard population in the Nordic countries when considered in isolation. However, the widespread decline in wintering numbers elsewhere across North-western Europe requires urgent pan-European action.
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| 3. |
- Dalby, Lars, et al.
(författare)
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The status of the Nordic populations of the Mallard (Anas platyrhynchos) in a changing world
- 2013
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Ingår i: Ornis Fennica. - : University of Helsinki. - 0030-5685. ; 90:1, s. 2-15
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Tidskriftsartikel (refereegranskat)abstract
- Dabbling ducks (Anas spp.) are important migratory quarry species, protected as a shared resource under international legislation. However, there is a lack of sufficient high-quality data on vital demographic rates and long-term trends in numbers to judge the conservation status of many duck populations at the flyway level. In response to reported declines in the North-West European flyway population of the Mallard, we compiled available data on this species in the Nordic countries up to 2010. Generally, national breeding numbers showed increasing trends, wintering abundance showed variable trends, and productivity measures indicated stable or increasing trends. Major knowledge gaps were identified, namely the size of hunting bags, the influence of the released Mallards and the role of short-stopping in explaining changing patterns of wintering abundance across the North-West European flyway. Numerically the Nordic breeding population appears in "good condition", and the wintering numbers have been either stable or increasing in the last two decades. The annual number of releases needs to be determined in order to judge the sustainability of the current levels of exploitation. Overall, none of the indicators showed alarming signs for the Mallard population in the Nordic countries when considered in isolation. However, the widespread decline in wintering numbers elsewhere across North-western Europe requires urgent pan-European action.
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| 4. |
- Ekström, Claes, et al.
(författare)
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Evaluation of recombinant human IGF-1/IGFBP-3 on intraventricular hemorrhage prevention and survival in the preterm rabbit pup model
- 2023
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Ingår i: Scientific Reports. - 2045-2322. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Insulin-like growth factor-1 (IGF-1) is essential for normal brain development and regulates processes of vascular maturation. The pathogenesis of intraventricular hemorrhage (IVH) relates to the fragility of the immature capillaries in the germinal matrix, and its inability to resist fluctuations in cerebral blood flow. In this work, using different experimental setups, we aimed to (i) establish an optimal time-point for glycerol-induction of IVH in relation to time-point of recombinant human (rh) IGF-1/rhIGFBP-3 administration, and (ii) to evaluate the effects of a physiologic replacement dose of rhIGF-1/rhIGFBP-3 on prevention of IVH and survival in the preterm rabbit pup. The presence of IVH was evaluated using high-frequency ultrasound and post-mortem examinations. In the first part of the study, the highest incidence of IVH (> 60%), occurred when glycerol was administered at the earliest timepoint, e.g., 6h after birth. At later time-points (18 and 24h) the incidence decreased substantially. In the second part of the study, the incidence of IVH and mortality rate following rhIGF-1/rhIGFBP-3 administration was not statistically different compared to vehicle treated animals. To evaluate the importance of maintaining intrauterine serum levels of IGF-1 following preterm birth, as reported in human interventional studies, additional studies are needed to further characterize and establish the potential of rhIGF-1/rhIGFBP-3 in reducing the prevalence of IVH and improving survival in the preterm rabbit pup.
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| 5. |
- Gram, Magnus, et al.
(författare)
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Insulin-Like Growth Factor 1 in the Preterm Rabbit Pup: Characterization of Cerebrovascular Maturation following Administration of Recombinant Human Insulin-Like Growth Factor 1/Insulin-Like Growth Factor 1-Binding Protein 3
- 2021
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Ingår i: Developmental Neuroscience. - : S. Karger AG. - 0378-5866 .- 1421-9859. ; 43:5, s. 281-295
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Tidskriftsartikel (refereegranskat)abstract
- Following preterm birth, serum levels of insulin-like growth factor 1 (IGF-1) decrease compared to corresponding in utero levels. A recent clinical trial indicated that supplementation with recombinant human (rh) IGF-1/rhIGF-binding protein 3 (rhIGF-1/rhIGFBP-3) prevents severe intraventricular hemorrhage (IVH) in extremely preterm infants. In a preterm rabbit pup model, we characterized endogenous serum and hepatic IGF-1, along with brain distribution of IGF-1 and IGF-1 receptor (IGF1R). We then evaluated the effects of rhIGF-1/rhIGFBP-3 on gene expression of regulators of cerebrovascular maturation and structure. Similar to preterm infants, serum IGF-1 concentrations decreased rapidly after preterm birth in the rabbit pup. Administration of rhIGF-1/rhIGFBP-3 restored in utero serum levels but was rapidly eliminated. Immunolabeled IGF1R was widely distributed in multiple brain regions, displaying an abundant density in the choroid plexus and sub-ependymal germinal zones. Increased IGF-1 immunoreactivity, distributed as IGF1R, was detected 4 h after rhIGF-1/rhIGFBP-3 administration. The rhIGF-1/rhIGFBP-3 treatment led to upregulation of choroid plexus genes involved in vascular maturation and structure, with corresponding protein translation for most of these genes. The preterm rabbit pup model is well suited for evaluation of IGF-1-based prevention of IVH. Administration of rhIGF-1/rhIGFBP-3 affects cerebrovascular maturation, suggesting a role for it in preventing preterm IVH.
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| 6. |
- Holmqvist, Fredrik, et al.
(författare)
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A decade of catheter ablation of cardiac arrhythmias in Sweden : ablation practices and outcomes
- 2019
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 0195-668X .- 1522-9645. ; 40:10, s. 820-830
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Catheter ablation is considered the treatment of choice for many tachyarrhythmias, but convincing 'real-world' data on efficacy and safety are lacking. Using Swedish national registry data, the ablation spectrum, procedural characteristics, as well as ablation efficacy and reported adverse events are reported.Methods and Results: Consecutive patients (≥18 years of age) undergoing catheter ablation in Sweden between 01 January 2006 and 31 December 2015 were included in the study. Follow-up (repeat ablation and vital status) was collected through 31 December 2016. A total of 26 642 patients (57 ± 15 years, 62% men), undergoing a total of 34 428 ablation procedures were included in the study. In total, 4034 accessory pathway/Wolff-Parkinson-White syndrome (12%), 7358 AV-nodal re-entrant tachycardia (21%), 1813 atrial tachycardia (5.2%), 5481 typical atrial flutter (16%), 11 916 atrial fibrillation (AF, 35%), 2415 AV-nodal (7.0%), 581 premature ventricular contraction (PVC, 1.7%), and 964 ventricular tachycardia (VT) ablations (2.8%) were performed. Median follow-up time was 4.7 years (interquartile range 2.7-7.0). The spectrum of treated arrhythmias changed over time, with a gradual increase in AF, VT, and PVC ablation (P < 0.001). Decreasing procedural times and utilization of fluoroscopy with time, were seen for all arrhythmia types. The rates of repeat ablation differed between ablation types, with the highest repeat ablation seen in AF (41% within 3 years). The rate of reported adverse events was low (n = 595, 1.7%). Death in the immediate period following ablation was rare (n = 116, 0.34%).Conclusion: Catheter ablations have shifted towards more complex procedures over the past decade. Fluoroscopy time has markedly decreased and the efficacy of catheter ablation seems to improve for AF.
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| 7. |
- Holmqvist, Niklas, et al.
(författare)
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Lake trophic status and bioaccumulation of polychlorinated biphenyls in benthic organisms: a comparison between littoral and profundal invertebrates
- 2005
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Ingår i: Canadian Journal of Fisheries and Aquatic Sciences. - 1205-7533. ; 62:6, s. 1201-1209
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the influence of lake trophic status on accumulation of polychlorinated biphenyls (PCBs) in littoral and profundal invertebrates from 19 lakes in southern Sweden. The PCB concentration in profundal chironomids (Chironomus sp.) was negatively correlated with lake trophy but the concentration in littoral crayfish (Pacifasticus leniusculus) was unrelated to shifting nutrient regimes. PCB concentrations in chironomids were negatively correlated, while crayfish did not correlate with lake total phosphorus. Two findings indicate that different processes determine bioaccumulation in littoral and profundal invertebrates: (i) a lack of correlation between PCB concentrations in crayfish and chironomids within lakes and (ii) some differences in congener distribution in the two species. We suggest a possible explanation in that chironomids are directly exposed to settling material from the pelagic zone, while crayfish are omnivorous and feed mainly in the littoral zone. A intensive investigation on one pond population could not reveal any individual factors, such as lipid content, size, or sex, influencing bioaccumulation of PCBs in crayfish.
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| 8. |
- Holmqvist, Niklas, et al.
(författare)
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Low levels of persistent organic pollutants (POPS) in New Zealand eels reflect isolation from atmospheric sources
- 2006
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Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491. ; 141:3, s. 532-538
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Tidskriftsartikel (refereegranskat)abstract
- Polychlorinated biphenyls (PCBs) and organic pesticides (i.e., DDTs) were measured in long finned eels (Anguilla dieffenbachii) in 17 streams on the west coast of South Island, New Zealand. Very low levels of PCBs and low levels of ppDDE were found. The concentrations of PCBs and ppDDE were not correlated within sites indicating that different processes determined the levels of the two pollutants in New Zealand eels. The PCBs probably originate from atmospheric transport, ppDDE levels are determined by land use and are higher in agriculture areas. The low contamination level of these aquatic systems seems to be a function of a low input from both long and short-range transport as well as few local point sources. No correlation could be found between lipid content and persistent organic pollutants (POPs) concentration (as shown in previous studies) in the eels which could be explained by low and irregular intake of the pollutants.
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| 9. |
- Holmqvist, Niklas
(författare)
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Persistent organic pollutants in benthic foodwebs
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Concentrations of persistent organic pollutants (POPs) in aquatic biota are dependent on several factors both on individual and on system level. Bioaccumulation of POPs in pelagic biota in lakes as well as fish in streams has been shown to be dependent on nutrient regime of the system. In lakes, POP concentrations in pelagic biota decrease with increasing lake trophy. In this thesis POP bioaccumulation in benthic biota in lakes were investigated. In profundal chironomids POP concentrations decreased with increasing lake trophy while concentration were independent of lake trophy in littoral signal crayfish (Pacifastacus leniusculus). Chironomids feed on settling pelagic phytoplankton while crayfish feeding are influenced by terrestrial input. In streams, PCB concentrations in crayfish were independent of nutrient regime. In earlier studies POP concentrations in stream living trout has been shown to increase with increasing nutrient regime. Trout are highly dependent on autotrophic energy while crayfish diet is influenced by terrestrial sources. No difference in POP concentrations in lake and stream living crayfish could be found but the variation were higher in streams. The more dynamic properties of streams compared to lakes are probably reflected in crayfish POP concentrations. In New Zealand, POP concentrations in Longfinned eels (Anguilla dieffenbachii) were investigated. Concentrations of POPs were low compared to other studies on eels. The low levels were explained with low atmospheric deposition due to local geographical conditions and few point sources. In crayfish no effect of age and lipid content could be found as been shown for fish. Crayfish has, contrary to fish, continuous moulting events and normally change shell at least once a year. Moulting is energy demanding and means a total utilization of energy stores like those containing lipids. POPs can then be fully or partially eliminated and the process creates a cycle of POP accumulation that occurs between moulting events- not over whole life span as in fish. Diet and bioaccumulation of POPs in crayfish were affected by intrapopulation parameters. Crayfish populations in some lakes were size segregated and larger crayfish were found in shallow areas of the littoral zone. Further, larger crayfish were feeding at a higher trophic level and had higher levels of POPs. We hypothesize that a combination of predation pressure, habitat availability and intraspecicfic interactions influence population distribution with following size dependent shifts in diet that influence the uptake of POPs in crayfish.
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| 10. |
- Holmqvist, Niklas, et al.
(författare)
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Persistent organic pollutants (POP) in a benthic omnivore - A comparison between lake and stream crayfish populations
- 2007
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Ingår i: Chemosphere. - : Elsevier BV. - 1879-1298 .- 0045-6535. ; 66:6, s. 1070-1078
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the accumulation of PCB and DDT in crayfish populations in 10 streams in southern Sweden. The results were compared with an earlier study on crayfish in lakes from the same area. We found that the concentration of pollutants in crayfish did not differ between the two types of systems. Variation in body burden was higher in stream living crayfish probably because of the higher influence from pollutants deposited in the catchment area and the more dynamic transport in streams. In streams, pp'-DDE concentrations were positively correlated to trophic status (total phosphorous) while PCB did not show any correlation with the nutrient regime. Further, mean Sigma PCB and p,p'-DDE concentrations in crayfish did not correlate in streams. We suggest that the sources of the two pollutants differ for stream living crayfish. The results indicate that crayfish in streams are affected to a higher degree to pollutants in the catchment area and the precipitation regime. In lakes, internal processes govern uptake of pollutants in crayfish.
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| 11. |
- Knutson, Hans-Kristian, et al.
(författare)
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Robust Multi-Objective Optimization of Chromatographic Rare Earth Element Separation
- 2017
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Ingår i: Advances in chemical Engineering and Science. - : Scientific Research Publishing, Inc.. - 2160-0406 .- 2160-0392. ; 7:4, s. 477-493
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Tidskriftsartikel (refereegranskat)abstract
- Rare earth elements are strategic commodities in many countries, and an important resource for the growing modern technology industry. As such, there is an increasing interest for development of rare earth element processing, and this work is a part of further development of chromatography as a rare earth element separation process method. Process optimization is pivotal for process development, and it is common that several competing objectives must be regarded. Chromatographic separation processes often consider competing objectives, such as productivity, yield, pool concentration and modifier consumption, which leads to Pareto optimal solutions. Adding robustness to a process is of great importance to account for process disturbances and uncertainties but generally comes with reduced performance of the other process objectives as a trade off. In this study, a model-based robust multi-objective optimization was carried out for batch-wise chromatographic separation of the rare earth elements samarium, europium and gadolinium, which was considered highly un-robust due to the neighbouring peaks proximity to the product pooling horizon. The results from the robust optimization were used to chart the required operation point changes for keeping the amount of failed batches at an acceptable level when a certain level of process disturbance was introduced. The loss of process performance due to the gained robustness was found to be in the range of 10% - 20% reduced productivity when comparing the robust and un-robust Pareto solutions at Pareto points with identical yield. The methodology presented shows how to increase robustness to a highly un-robust system while still keeping multiple objectives at their optima.
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| 12. |
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| 13. |
- Larsson, Per, et al.
(författare)
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Heavy metals and stable isotopes in a benthic omnivore in a trophic gradient of lakes
- 2007
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Ingår i: Environmental Science & Technology. - : American Chemical Society (ACS). - 1520-5851 .- 0013-936X. ; 41:17, s. 5973-5979
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Tidskriftsartikel (refereegranskat)abstract
- Heavy metals (Cd, Hg, and Pb) and stable isotopes (N-15, C-13) in crayfish (Pacifastacus leniusculus) were studied in a trophic gradient of lakes (N = 19) in southern Sweden. Trophic indicators of the lakes as total phosphorus (tot-P) varied from 5 to 93 mu g/L. The examined lakes had no known point sources of heavy metals, but the catchment areas varied from mainly forested to agricultural land. Cd and Hg in crayfish were affected by the trophic status of the lakes, showing significant negative relationship with tot-P, total nitrogen, and chlorophyll A content and a positive relationship with lake transparency (Secchi depth). The concentration of these two heavy metals was thus higher in crayfish in the oligotrophic lakes and decreased linearly to the eutrophic ones. Pb was not related to any lake variable. Stable isotopes of carbon (delta C-13) and nitrogen (615N) in crayfish were a reflection of that found in the sediment as shown by positive linear relationships for the lakes. In the sediment of the lakes, delta C-13 signature showed significant negative relationships with the trophic indicators but positive results were shown for lake transparency. The trophic gradient of the lakes was reflected by delta C-13 in the sediment and in the crayfish. 615N in crayfish was a reflection of 615N in the sediment but the relationship was not coupled to the trophic statue of the lakes. The results from the study show that Cd and Hg in benthic omnivores as crayfish are affected by ecological processes in lakes, such as eutrophication. Stable isotopes, such as 13C and 15 N, can be used to study these ecological processes.
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| 14. |
- Nyström, Per, et al.
(författare)
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Crayfish in lakes and streams: individual and population responses to predation, productivity and substratum availability
- 2006
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Ingår i: Freshwater Biology. - : Wiley. - 0046-5070 .- 1365-2427. ; 51:11, s. 2096-2113
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Tidskriftsartikel (refereegranskat)abstract
- 1. In a correlative study, we investigated the relative importance of fish predation, refuge availability and resource supply in determining the abundance and size distributions of the introduced and omnivorous signal crayfish (Pacifastacus leniusculus) in lakes and streams. Moreover, the biomass and food selection of predatory fish was estimated in each habitat type and stable isotopes of carbon and nitrogen were measured in perch (Perca fluviatilis), the dominant predator in the lakes, and in its potential food sources (crayfish, juvenile roach and isopods). 2. In lakes, crayfish were the most frequent prey in large perch (46%), followed by other macroinvertebrates (26%, including the isopod Asellus aquaticus) and small fish (25%). Crayfish and fish dominated the gut contents of large perch with respect to biomass. Nitrogen signatures showed that perch were one trophic level above crayfish (approx. 3.4 parts per thousand) and a two-source mixing model using nitrogen isotope values indicated that crayfish (81%) contributed significantly more to perch isotope values than did juvenile roach (19%). A positive correlation was found between the abundance of crayfish and the biomass of large perch. Crayfish abundance in lakes was also positively correlated with the proportion of cobbles in the littoral zone. Lake productivity (chlorophyll a) was positively correlated with crayfish size, but not with crayfish abundance. 3. In streams, brown trout (Salmo trutta) were the most abundant predatory fish. Gut contents of large trout in a forested stream showed that terrestrial insects were the most frequently found prey (60%), followed by small crayfish (27%) and isopods (27%). In contrast to lakes, the relative abundance of crayfish was negatively correlated with the total biomass of predatory fish and with total biomass of trout. However, abundance of crayfish at sites with a low biomass of predatory fish varied considerably and was related to substratum grain size, with fewer crayfish being caught when the substratum was sandy or dominated by large boulders. The mean size of crayfish was greater at stream sites with a high standing stock of periphyton, but neither predator biomass nor substratum grain size was correlated with crayfish size. 4. Our results suggest that bottom-up processes influence crayfish size in lakes and streams independent of predator biomass and substratum availability. However, bottom-up processes do not influence crayfish abundance. Instead, substratum availability (lakes) and interactions between predation and substratum grain size (streams) need to be considered in order to predict crayfish abundance.
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| 15. |
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| 16. |
- Olsson, Karin, et al.
(författare)
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Does natural acidity mediate interactions between introduced brown trout, native fish, crayfish and other invertebrates in West Coast New Zealand streams?
- 2006
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Ingår i: Biological Conservation. - : Elsevier BV. - 1873-2917 .- 0006-3207. ; 130:2, s. 255-267
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Tidskriftsartikel (refereegranskat)abstract
- The presence of introduced brown trout (Salmo trutta) on the distribution of native crayfish (Paranephrops planifrons), native galaxiid fishes (Galaxias spp.) and invertebrate fauna was investigated in 18 West Coast New Zealand streams (8 with trout and 10 without trout) differing in chemical characteristics. Gut contents of trout, crayfish and eels were also examined to evaluate whether competition or predation could be linked to the patterns found. Abundances of crayfish and galaxiids were significantly lower in streams with trout, but in streams without trout, substrate size was one of the most important factors determining crayfish abundance. In contrast to crayfish, other macroinvertebrates were more abundant in trout streams than streams without trout and significantly more taxa were found in streams with trout. Macroinvertebrate abundance was related to environmental factors, such as pH, substrate, depth and total nitrogen. Gut content analysis showed an overlap in diet (mostly invertebrates) between trout and eels. Crayfish, however, had a more omnivorous diet where detritus was the most frequently occurring food material. Differences in chemical characteristics marked the streams with and without trout. Thus, trout were not present in streams with pH < 6.0. Crayfish and galaxiids were present in streams with pH ranging from 4.1 to 7.9, and those with pH < 6.0 may function as trout-free refuges where larger populations of these species may persist. However, other macroinvertebrate taxa may be more negatively affected by acidification than by trout. By protecting naturally acidic, brown water streams, New Zealand crayfish and galaxiid fish populations can be conserved within geographic areas where trout are present.
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| 17. |
- Ortenlöf, Niklas, et al.
(författare)
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Characterization of choroid plexus in the preterm rabbit pup following subcutaneous administration of recombinant human IGF-1/IGFBP-3
- 2023
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Ingår i: Fluids and Barriers of the CNS. - 2045-8118. ; 20:1
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Tidskriftsartikel (refereegranskat)abstract
- Insulin-like growth factor-1 (IGF-1) is essential for normal brain development and regulates essential processes of vascular maturation and stabilization. Importantly, preterm birth is associated with reduced serum levels of IGF-1 as compared to in utero levels. Using a preterm rabbit pup model, we investigated the uptake of systemic recombinant human (rh) IGF-1 in complex with its main binding protein IGF-binding protein 3 (BP-3) to the brain parenchyma via the choroid plexus. Five hours after subcutaneous administration, labeled rhIGF-1/rhIGFBP-3 displayed a widespread presence in the choroid plexus of the lateral and third ventricle, however, to a less degree in the fourth, as well as in the perivascular and subarachnoid space. We found a time-dependent uptake of IGF-1 in cerebrospinal fluid, decreasing with postnatal age, and a translocation of IGF-1 through the choroid plexus. The impact of systemic rhIGF-1/rhIGFBP-3 on IGF-1 receptor activation in the choroid plexus decreased with postnatal age, correlating with IGF-1 uptake in cerebrospinal fluid. In addition, choroid plexus gene expression was observed to increase with postnatal age. Moreover, using choroid plexus in vitro cell cultures, gene expression and protein synthesis were further investigated upon rhIGF-1/rhIGFBP-3 stimulation as compared to rhIGF-1 alone, and found not to be differently altered. Here, we characterize the uptake of systemic rhIGF-1/rhIGFBP-3 to the preterm brain, and show that the interaction between systemic rhIGF-1/rhIGFBP-3 and choroid plexus varies over time.
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| 18. |
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| 19. |
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| 20. |
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| 21. |
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| 22. |
- Persson, M E, et al.
(författare)
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Large variation in lipid content, ΣPCB and δ13C within individual Atlantic salmon (Salmo salar)
- 2007
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Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491. ; 145:1, s. 131-137
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Many studies that investigate pollutant levels, or use stable isotope ratios to define trophic level or animal origin, use different standard ways of sampling (dorsal, whole filet or whole body samples). This study shows that lipid content, ΣPCB and δ13C display large differences within muscle samples taken from a single Atlantic salmon. Lipid- and PCB-content was lowest in tail muscles, intermediate in anterior-dorsal muscles and highest in the stomach (abdominal) muscle area. Stable isotopes of carbon (δ13C) showed a lipid accumulation in the stomach muscle area and a depletion in tail muscles. We conclude that it is important to choose an appropriate sample location within an animal based on what processes are to be studied. Care should be taken when attributing persistent pollutant levels or stable isotope data to specific environmental processes before controlling for within-animal variation in these variables. Lipid content, ΣPCB and δ13C vary to a large extent within Atlantic salmon, therefore, the sample technique for individual fish is of outmost importance for proper interpretation of data.
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| 23. |
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| 24. |
- Rebetz, Johan, et al.
(författare)
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Fiber mediated receptor masking in non-infected bystander cells restricts adenovirus cell killing effect but promotes adenovirus host co-existence.
- 2009
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 4:12
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Tidskriftsartikel (refereegranskat)abstract
- The basic concept of conditionally replicating adenoviruses (CRAD) as oncolytic agents is that progenies generated from each round of infection will disperse, infect and kill new cancer cells. However, CRAD has only inhibited, but not eradicated tumor growth in xenograft tumor therapy, and CRAD therapy has had only marginal clinical benefit to cancer patients. Here, we found that CRAD propagation and cancer cell survival co-existed for long periods of time when infection was initiated at low multiplicity of infection (MOI), and cancer cell killing was inefficient and slow compared to the assumed cell killing effect upon infection at high MOI. Excessive production of fiber molecules from initial CRAD infection of only 1 to 2% cancer cells and their release prior to the viral particle itself caused a tropism-specific receptor masking in both infected and non-infected bystander cells. Consequently, the non-infected bystander cells were inefficiently bound and infected by CRAD progenies. Further, fiber overproduction with concomitant restriction of adenovirus spread was observed in xenograft cancer therapy models. Besides the CAR-binding Ad4, Ad5, and Ad37, infection with CD46-binding Ad35 and Ad11 also caused receptor masking. Fiber overproduction and its resulting receptor masking thus play a key role in limiting CRAD functionality, but potentially promote adenovirus and host cell co-existence. These findings also give important clues for understanding mechanisms underlying the natural infection course of various adenoviruses.
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| 25. |
- Sellberg, Anton, et al.
(författare)
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Development and Optimization of a Single Column Analog Model for a Multi-Column Counter-Current Solvent Gradient Purification Process
- 2017
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Ingår i: 27th European Symposium on Computer Aided Process Engineering. - 1570-7946. - 9780444639707 - 0444639705 ; 40, s. 187-192
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Bokkapitel (refereegranskat)abstract
- This contribution presents a modeling and optimization method for multi-column counter-current purification (MCSGP) processes. The model is based on conventional column models and by using the symmetric and cyclic steady state characteristics of the process a single column analog model was developed. The model have been used for dynamic optimization of the MCSGP process. The optimization was based on a simultaneous method where the control and state variables were discretized using a direct and local collocation method on finite elements in the temporal dimension and a finite volume weighted essentially non-oscillatory (WENO) scheme in the spatial dimension. The resulting nonlinear program (NLP) were solved using an interior point method.The case study presented shows that the zero-order hold elution trajectories, developed for single column batch operation, can be extended to semi-continuous multi-column chromatography with product recycling. The optimization results is composed of a set of operating conditions where the product was upgraded to 95% purity with 99% process yield.
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| 26. |
- Stenroth, Patrik, et al.
(författare)
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Stable isotopes as an indicator of diet in omnivorous crayfish (Pacifastacus leniusculus): the influence of tissue, sample treatment, and season
- 2006
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Ingår i: Canadian Journal of Fisheries and Aquatic Sciences. - 1205-7533. ; 63:4, s. 821-831
-
Tidskriftsartikel (refereegranskat)abstract
- Stable isotopes have been used to analyse food webs and (or) trace movements of animals for about 30 years. There has been some debate on the use of different tissues and treatments before isotope analysis, as well as on seasonal effects. We found different crayfish (Pacifastacus leniusculus) tissues (muscle, hepatopancreas, exoskeleton, gill, and whole body) to have different isotope values. Lipid extraction made whole-body carbon isotope values higher but had no effect on nitrogen isotope values. Acidification made whole-body isotope values lower. For crayfish, there was no seasonal or interannual variation in isotope values. In contrast to studies based on gut content analysis, we found adult crayfish to be at least as carnivorous as young-of-the-year crayfish. Earlier studies often have assumed that each food source contributes both nitrogen and carbon in equal proportions. Omnivores do not fit easily into this view. We suggest that nitrogen and carbon in an organism could come from different sources. Adopting this view for a pond food web could render crayfish both predators and detritivores as crayfish prey on nitrogen sources (other invertebrates) and consume large amounts of detritus to satisfy their carbon demand.
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| 27. |
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| 28. |
- Stenroth, Patrik, et al.
(författare)
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The influence of productivity and width of littoral zone on the trophic position of a large-bodied omnivore.
- 2008
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Ingår i: Oecologia. - : Springer Science and Business Media LLC. - 1432-1939 .- 0029-8549. ; 156, s. 681-690
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Tidskriftsartikel (refereegranskat)abstract
- Omnivory is common in many food webs. Omnivores in different habitats can potentially change their feeding behaviour and alter their trophic position and role according to habitat conditions. Here we examine the trophic level and diet of the omnivorous signal crayfish (Pacifastacus leniusculus) in gradients of trophic status and lake size, both of which have been previously suggested to affect trophic position of predators separately or combined as productive space. We found the trophic position of omnivorous crayfish to be positively correlated with lake trophic status, but found no evidence for any influence of lake size or productive space on crayfish trophic position. The higher trophic position of crayfish in eutrophic lakes was largely caused by a shift in crayfish diet and not by an increase in trophic links in basal parts of the food web. Hence, our results support the "productivity hypothesis," suggesting that food chains can be longer in more productive systems. Furthermore, stable isotope data indicated that larger crayfish are more predatory than smaller crayfish in lakes with wider littoral zones. Wider littoral zones promoted the development of intrapopulation differences in trophic position whereas narrow littoral zones did not. Hence, differences in habitat quality between and within lakes seem to influence the trophic positions of omnivorous crayfish.
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| 29. |
- Törneman, Niklas, et al.
(författare)
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Litteraturstudie om kemiska ämnen och nanopartiklar i produkter inför screening 2007
- 2006
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- SWECO VIAK har på uppdrag av Naturvårdsverket genomfört en litteraturstudie av ett 80 tal ämnen som kan bli aktuella för screening inom den nationella miljöövervakningen. Dessutom har en litteraturstudie om nanopartiklar genomförts.Litteraturstudierna omfattade fysiokemisk information, begränsningar och förbud som berör ämnena, toxikologiska och ekotoxikologiska data, hantering och emissioner av ämnena, spridning och omvandling i naturen, förekomst i miljö och människa, en PBT bedömning (dvs. en bedömning av ämnenas motstånd mot nedbrytning, ämnenas bioackumulationspotential och ämnenas toxicitet), en bedömning av möjliga matriser där ämnena kan återfinnas samt möjliga metoder för analys av ämnena.För att förbättra överskådligheten presenteras detaljerad information om de olika ämnena i ämnesrapporter som bifogas huvudrapporten. I själva rapporten redovisas varje ämnesgrupp i översiktliga tabeller där en del av informationen om varje ämne återfinns.En rad olika informationskällor har använts. Dessa innefattar olika ämnesdatabaser, rapporter från statliga och överstatliga organ, vetenskapliga databaser där nyare information återfinns och olika tillverkares/importörers/exportörers information om de olika ämnena.De studerade ämnesgrupperna är, med en kortfattad beskrivning:Aminer är en grupp alifatiska eller aromatiska ämnen där minst en amingrupp ingår. Alla ämnen i gruppen är faroklassificerade och tillgången på toxikologiska och ekotoxikologisk data är förhållandevis god. Ämnena inom gruppen används bl.a. som smörjmedelstillsatser och tre ämnen i gruppen är högvolymsprodukter. Några av ämnena bedöms vara något intressanta för screening pga. de påträffats i miljön och kan ha negativa hälso- och miljöeffekter.Biocider är en liten grupp ämnen som bl.a. används i färger. Alla ämnena i gruppen är faroklassificerade som mycket giftiga för vattenlevande organismer och tillgången på toxikologiska och ekotoxikologisk data är förhållandevis god. Ett av ämnena i gruppen bedöms vara något intressant för screening pga. de förhållandevis låga ekotoxikologiska effekthalterna och den icke försumbara mängden som registreras.Estrar innefattar både estrar med enkla och polyaromatiska substituenter och alifatiska estrar. Två ämnen i gruppen är faroklassificerade som mycket giftiga för vattenlevande organismer och tillgången på ekotoxikologiska data är förhållandevis god. Ämnena ingår i olika industriella kemikalieprodukter och de flesta är högvolymskemikalier i EU. Två av ämnena i gruppen bedöms vara något intressanta för screening pga. de förhållandevis låga ekotoxikologiska effekthalterna och den icke försumbara mängden som registreras.Heterocykliska ämnen innefattar fyra ämnen vars enda strukturella likhet är att de innehåller minst en aromatisk ring. Flera ämnen i gruppen är faroklassificerade som mycket giftiga för vattenlevande organismer och tillgången på ekotoxikologisk data är begränsad. Ämnena ingår i olika industriella kemikalieprodukter och inga är högvolymskemikalier i EU. Ämnena i gruppen bedöms vara mindre intressanta för screening. Framförallt för att förhållandevis små mängder registreras årligen.Organiska fosfater och svavelföreningar innefattar tre ämnen utan strukturella likheter. Alla tre ämnen är högvolymsprodukter i EU och används som tillsatsämnen i kemikalie/plast -industrin. Ett av ämnena i gruppen är något intressant för screening eftersom registreringen ökar samtidigt som ämnet är misstänkt cancerframkallande. Dock är registreringen av detta ämne i Sverige förhållandevis låg (20 ton/år).Organiska halogener innefattar åtta ämnen. Samtliga är faroklassificerade som mycket giftiga för vattenlevande organismer och tillgången på ekotoxikologiska data är god. Fyra ämnen är dessutom misstänkt cancerogena. De flesta ämnen i gruppen är bekämpningsmedel och fyra ämnen är högvolymsprodukter. Flera ämnena i gruppen bedöms vara intressanta för screening pga. mycket hög giftighet gentemot vattenlevande organismer. Extra intressant i denna grupp är cypermetrin vars användning förväntas öka för att skydda timmerupplag mot skadedjurangrepp.Organiska jonföreningar innefattar sexton anjoniska ämnen som alla innehåller minst en bensenring. Flera av ämnena är alkylbensensulfonater och några av dessa har linjära alkylgrupper vilket innebär att de är s.k. linjära alkylbensensulfonater (LAS). Inga av ämnena i gruppen är faroklassificerade. Ämnen förekommer främst i olika rengörings- och ytbehandlingsprodukter och elva ämnen i gruppen är högvolymsprodukter i EU. Tillgången på ekotoxikologiska data är varierande men flera av ämnena tycks vara relativt giftiga för vattenlevande organismer. Flera ämnen i denna grupp bedöms vara intressanta för screening främst för att stora mängder registreras årligen samtidigt som den huvudsakliga användningen är i sådana produkter där en spridning till omgivningen via t.ex. reningsverk är möjlig.Pigmentämnen innefattar 10 gula, 3 orange, 13 röda, 3 lila, 1 blå och 2 gröna pigmentämnen. Hela gruppen är mycket heterogen vad gäller molekylstruktur, egenskaper, farlighet förr människa och miljö samt registrerade mängder. I denna studie är detta den grupp av ämnen som det finns minst information om i förhållande till den mängd som registreras. Trots bristen på information bör inte denna grupp uteslutas från screening. Däremot kan det viktigaste kriteriet för urval av pigmentämnen till screening tänkas vara den registrerade mängden. Ur detta hänseende framstår det enda blå pigmentämnet som en lämplig kandidat med en registrerad mängd av 1250 ton år 2004 samtidigt som det finns förhållandevis mycket information om detta ämne.Betongtillsatser innefattar 7 ämnen vars enda gemensamma nämnare är att de alla används som tillsatsämnen vid betongtillblandning. Flertalet av dessa ämnen är faroklassificeradeoch alla ämnen är högvolymsprodukter inom EU samtidigt som mycket stora mängder registreras i Sverige årligen (100 – 12000 ton). Tillgången på ekotoxikologisk data är varierande men flera av ämnena tycks vara relativt giftiga för vattenlevande organismer. Flera ämnen i denna grupp bedöms vara intressanta för screening främst för att mycket stora mängder registreras årligen samtidigt som deras miljöfarlighet inte är obetydlig.Nanopartiklar är inte en ämnesgrupp i egentlig mening. Istället är detta en materialkategori som kännetecknas av rymdstrukturer på en skala < 100 nm. I denna rapport behandlas främst nanopartiklar vilket innefattar både linjära och partikulära nanomaterial men inte nanoytor (ytbeläggningar). Nanopartiklar kemiska sammansättning varierar mellan helt oorganiska nanopartiklar, kolnanopartiklar och nanokompositer. Pga. av sin storlek kan nanopartiklar passera en rad biologiska barriärer inklusive cellmembran och blod-hjärn barriären. Nanopartiklars speciella egenskaperna (t.ex. hög reaktivitet) beror bl.a. på den extremt stora ytan i förhållande till volymen vilket innebär att en stor andel av alla atomer befinner sig på ytan av strukturer, där de har en större möjlighet till att interagera med andra abiotiska eller biologiska material. Nanopartiklar har i laboratorieförsök visat sig kunna ha negativa hälsoeffekter. Trots detta finns det endast begränsad kunskap om i vilken grad som exponering för nanopartiklar leder till faktiska hälsoeffekter. Det går inte i nuläget att kvantifiera varken import, export eller mängden nanopartiklar som används i Sverige. Orsakerna är att det i nuläget inte finns några krav på att material eller produkter som innehåller nanopartiklar skall rapporteras till någon myndighet, varken i Sverige eller på EU-nivå. Dessutom finns det en mycket lång rad användningsområden för nanopartiklar, vilket gör att det kan vara besvärligt att sammanställa statistik som på ett tillförlitligt sätt kvantifierar användning, export och import. Det faktum att mycket stora mängder nanopartiklar (framförallt kolpulverbaserade nanopartiklar) använts i en lång rad år före begreppet nanopartiklar uppmärksammades, försvårar statistiksammanställningen ytterligare.
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| 30. |
- Törneman, Niklas, et al.
(författare)
-
Screening av betongtillsatser
- 2008
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- SWECO Environment har på uppdrag av Naturvårdsverket utfört en screeningsstudie av dietanolamin (samt vid enstaka tillfällen trietanolamin) i Sverige. Dietanolamin har mätts i ett flertal matriser i provpunkter som har påverkats av olika antropogena källor. Provtagningen genomfördes nationellt med provpunkter som valdes av Naturvårdsverket och SWECO samt regionalt med provpunkter som valdes av respektive länsstyrelse. Resultaten från den regionala samt den nationella provtagningen samutvärderades. De potentiella källor som främst undersöktes var: • Betonggjutning där dietanolaminer kan läcka från betongen både under själva gjutningen och under härdningen. • Industrier där dietanolaminer tillverkas • Reningsverk Svenska bakgrundshalter i ytvatten och sediment mättes i referenssjöar. Dessutom mättes bakgrundshalter i jord i anslutning till referenssjöarna.Projektets målsättningar var:att utröna huruvida dietanolamin är vanligt förekommande i miljön, • att utröna om dietanolamin förekommer nära de platser där det tillverkas eller används i stora volymer, • att utröna vilka matriser som dietanolamin huvudsakligen förekommer i • samt att översiktligt bedöma huruvida uppmätta halter utgör problem för hälsa och/eller miljö. De matriser som undersöktes var jord, grundvatten, ytvatten, sediment, dagvatten, sediment från dagvattenbrunnar, samt avloppsvatten, slam och utflödesvatten från reningsverk. Svenska bakgrundshalter i sediment mättes i referenssjöar. Bakgrundshalter i jord mättes i anslutning till referenssjöarna.Slutsatser och rekommendationer Di- och trietanolamin påträffades endast vid ett fåtal tillfällen i anslutning till mycket stora punktkällor (ett infrastrukturprojekt med stora gjutningsarbeten samt en fabrik där etanolaminer tillverkas). Detta visar att dessa ämnen inte är allmänt spridda i miljön trots de mycket stora mängder som används årligen i Sverige. En trolig orsak är att dessa ämnen bryts ner förhållandevis lätt i den yttre miljön. De påträffade halterna vid utsläppspunkterna översteg i några fall de koncentrationer som skall undvikas för att med säkerhet undvika negativa effekter i den akvatiska miljön. Eftersom spädningen efter utsläppspunkten är mycket hög så innebär detta dock att halterna i recipienter kraftigt understiger möjliga effektnivåer. Resultatet från screeningen ger inga belägg för något behov av vidare screening av etanolaminer.
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| 31. |
- von Olshausen, Gesa, et al.
(författare)
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Cardiac tamponades related to interventional electrophysiology procedures are associated with higher risk of short-term hospitalization for pericarditis but favourable long-term outcome
- 2023
-
Ingår i: Europace. - : Oxford University Press. - 1099-5129 .- 1532-2092. ; 25:6
-
Tidskriftsartikel (refereegranskat)abstract
- AIMS: To investigate the association of iatrogenic cardiac tamponades as a complication of invasive electrophysiology procedures (EPs) and mortality as well as serious cardiovascular events in a nationwide patient cohort during long-term follow-up.METHODS: From the Swedish Catheter Ablation Registry between 2005 and 2019, a total of 58 770 invasive EPs in 44 497 patients were analysed. From this, all patients with periprocedural cardiac tamponades related to invasive EPs were identified (n = 200; tamponade group) and matched (1:2 ratio) to a control group (n = 400). Over a follow-up of 5 years, the composite primary endpoint-death from any cause, acute myocardial infarction, transitory ischaemic attack (TIA)/stroke, and hospitalization for heart failure-revealed no statistically significant association with cardiac tamponade [hazard ratio (HR) 1.22 (95% CI, 0.79-1.88)]. All single components of the primary endpoint as well as cardiovascular death revealed no statistically significant association with cardiac tamponade. Cardiac tamponade was associated with a significantly higher risk with hospitalization for pericarditis [HR 20.67 (95% CI, 6.32-67.60)].CONCLUSION: In this nationwide cohort of patients undergoing invasive EPs, iatrogenic cardiac tamponade was associated with an increased risk of hospitalization for pericarditis during the first months after the index procedure. In the long-term, however, cardiac tamponade revealed no significant association with mortality or other serious cardiovascular events.
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| 32. |
- von Olshausen, Gesa, et al.
(författare)
-
Cardiac tamponades related to interventional electrophysiology procedures are associated with higher risk of short-term hospitalization for pericarditis but favourable long-term outcome.
- 2023
-
Ingår i: Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology. - : Oxford University Press. - 1532-2092 .- 1099-5129. ; 25:6
-
Tidskriftsartikel (refereegranskat)abstract
- To investigate the association of iatrogenic cardiac tamponades as a complication of invasive electrophysiology procedures (EPs) and mortality as well as serious cardiovascular events in a nationwide patient cohort during long-term follow-up.From the Swedish Catheter Ablation Registry between 2005 and 2019, a total of 58 770 invasive EPs in 44 497 patients were analysed. From this, all patients with periprocedural cardiac tamponades related to invasive EPs were identified (n = 200; tamponade group) and matched (1:2 ratio) to a control group (n = 400). Over a follow-up of 5 years, the composite primary endpoint-death from any cause, acute myocardial infarction, transitory ischaemic attack (TIA)/stroke, and hospitalization for heart failure-revealed no statistically significant association with cardiac tamponade [hazard ratio (HR) 1.22 (95% CI, 0.79-1.88)]. All single components of the primary endpoint as well as cardiovascular death revealed no statistically significant association with cardiac tamponade. Cardiac tamponade was associated with a significantly higher risk with hospitalization for pericarditis [HR 20.67 (95% CI, 6.32-67.60)].In this nationwide cohort of patients undergoing invasive EPs, iatrogenic cardiac tamponade was associated with an increased risk of hospitalization for pericarditis during the first months after the index procedure. In the long-term, however, cardiac tamponade revealed no significant association with mortality or other serious cardiovascular events.
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| 33. |
- Wallenquist, Ulrika, et al.
(författare)
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Ibuprofen attenuates the inflammatory response and allows formation of migratory neuroblasts from grafted stem cells after traumatic brain injury
- 2012
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Ingår i: Restorative Neurology and Neuroscience. - 0922-6028 .- 1878-3627. ; 30:1, s. 9-19
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: There is hope for neural stem and progenitor cells (NSPC) to enhance regeneration when transplanted to the injured brain after traumatic brain injury (TBI). So far, the therapeutic effects of NSPC transplantation have been hampered mainly by the notable death of the transplanted cells. Neuroinflammation may lead to additional cell death after TBI and we hypothesized that survival of grafted NSPC could be enhanced by anti-inflammatory treatment. Methods: Mice that were subjected to controlled cortical impact TBI and grafted with NSPC, were treated with the non-steroidal anti-inflammatory drug ibuprofen. Results: Ibuprofen was found to down-regulate the TBI-induced inflammatory response. In addition, migrating neuroblasts from transplanted cells were observed near the contusion and in the ipsilateral hippocampus in ibuprofen-treated animals only, suggesting that the anti-inflammatory treatment had beneficial effects on graft survival and/or differentiation. However, Morris Water Maze performance or TBI-induced tissue loss was not influenced by ibuprofen treatment. Conclusions: Our data suggests that anti-inflammatory strategies may be a complement to enhance the outcome for the cell transplants following TBI.
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