| 1. |
- Degerman, E, et al.
(författare)
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Are fish populations in temperate streams affected by crayfish? - A field survey and prospects
- 2007
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Ingår i: Environmental Biology of Fishes. - : Springer Science and Business Media LLC. - 0378-1909 .- 1573-5133. ; 78:3, s. 231-239
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Tidskriftsartikel (refereegranskat)abstract
- Fish populations may be affected by predation and competition from various types of organisms, among which crayfish have been suggested as important actors. We here present results from stream surveys, suggesting that neither native noble, Astacus astacus, nor introduced signal crayfish, Pacifastacus leniusculus, necessarily affect fish population densities in temperate stream communities. Comparisons of fish densities within stream sites between years with absence and presence of crayfish showed no effect of either crayfish species. A further analysis of changes in fish densities between periods without and with crayfish in low, intermediate and high densities revealed that crayfish density did neither have an effect on fish densities. Our study is one of exceptionally few that consider the above aspects in long-term perspectives in natural systems, and we discuss that previously reported divergent results of cray. sh effects on. sh may be highly dependent on specific species and methods used, and that the effects of cray. sh on. sh populations deserve further attention to enable reliable predictions of community processes in streams.
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| 2. |
- Del Tredici, Andria L., et al.
(författare)
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Identification of novel selective V-2 receptor non-peptide agonists
- 2008
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Ingår i: Biochemical Pharmacology. - : Elsevier BV. - 0006-2952 .- 1356-1839. ; 76:9, s. 1134-1141
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Tidskriftsartikel (refereegranskat)abstract
- Peptides with agonist activity at the vasopressin V-2 receptor are used clinically to treat fluid homeostasis disorders such as polyuria and central diabetes insipidus. of these peptides, the most commonly used is desmopressin, which displays poor bioavailability as well as potent activity at the V-1b receptor, with possible stress-related adverse effects. Thus, there is a strong need for the development of small molecule chemistries with selective V-2 receptor agonist activity. Using the functional cell-based assay Receptor Selection and Amplification Technology (R-SAT (R)), a screening effort identified three small molecule chemotypes (AC-94544, AC-88324, and AC-110484) with selective agonist activity at the V-2 receptor. One of these compounds, AC-94544, displayed over 180-fold selectivity at the V-2 receptor compared to related vasopressin and oxytocin receptors and no activity at 28 other G protein-coupled receptors (GPCRs). All three compounds also showed partial agonist activity at the V-2 receptor in a cAMP accumulation assay. In addition, in a rat model of central diabetes insipidus, AC-94544 was able to significantly reduce urine output in a dose-dependent manner. Thus, AC-94544, AC-88324, and AC-110484 represent novel opportunities for the treatment of disorders associated with V-2 receptor agonist deficiency.
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| 3. |
- Haitina, Tatjana, et al.
(författare)
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Expression profile of the entire family of Adhesion G protein-coupled receptors in mouse and rat
- 2008
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Ingår i: BMC Neuroscience. - : BioMed Central. - 1471-2202. ; 9, s. 43-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUNDThe Adhesion G protein-coupled receptors (GPCRs) are membrane-bound receptors with long N termini. This family has 33 members in humans. Several Adhesion GPCRs are known to have important physiological functions in CNS development and immune system response mediated by large cell surface ligands. However, the majority of Adhesion GPCRs are still poorly studied orphans with unknown functions.RESULTSIn this study we performed the extensive tissue localization analysis of the entire Adhesion GPCR family in rat and mouse. By applying the quantitative real-time PCR technique we have produced comparable expression profile for each of the members in the Adhesion family. The results are compared with literature data and data from the Allen Brain Atlas project. Our results suggest that the majority of the Adhesion GPCRs are either expressed in the CNS or ubiquitously. In addition the Adhesion GPCRs from the same phylogenetic group have either predominant CNS or peripheral expression, although each of their expression profile is unique.CONCLUSIONOur findings indicate that many of Adhesion GPCRs are expressed, and most probably, have function in CNS. The related Adhesion GPCRs are well conserved in their structure and interestingly have considerable overlap in their expression profiles, suggesting similarities among the physiological roles for members within many of the phylogenetically related clusters.
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| 4. |
- Henningson, Maria, et al.
(författare)
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Absence of the common IGF1 19 CA-repeat allele is more common among BRCA1 mutation carriers than among non-carriers from BRCA1 families.
- 2007
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Ingår i: Familial Cancer. - : Springer Science and Business Media LLC. - 1389-9600 .- 1573-7292. ; 6:4, s. 445-452
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Tidskriftsartikel (refereegranskat)abstract
- BRCA1 mutations predispose to early-onset breast cancer. We previously reported an association between absence of the common IGF1 19 CA-repeat allele (IGF1-19/-19) and being a BRCA1 mutation carrier in young women from breast cancer high-risk families. Others have reported a four-fold risk of premenopausal breast cancer in women with a family history and the IGF1-19/-19 genotype. The aim of this study was to investigate whether the IGF1-19/-19 genotype was associated with being a BRCA1 mutation carrier among women from BRCA1 families. DNA was available from 268 women with known BRCA1 status from the South Swedish Health Care Region. IGF1 genotyping was successfully performed with fragment analysis in 211 women from 96 families. The IGF1-19/-19 genotype was significantly more common among BRCA1 mutation carriers (14.2%) than among non-carriers (4.8%), OR 3.3 (95%CI 1.11-9.78, P = 0.03) adjusted for family clustering. We confirmed our previous finding of an association between the IGF1-19/-19 genotype and BRCA1 mutation status. Since the IGF1-19/-19 genotype in combination with OC use or multiparity confers an increased risk for early onset breast cancer in high-risk women and in women from the general population, future studies are needed to elucidate the importance of the IGF1-19/-19 genotype concerning the variability in breast cancer risk among BRCA1 mutation carriers.
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| 5. |
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| 6. |
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| 7. |
- Lehmann, Fredrik, 1976, et al.
(författare)
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Design, parallel synthesis and SAR of novel urotensin II receptor agonists
- 2007
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Ingår i: European Journal of Medicinal Chemistry. - : Elsevier BV. - 0223-5234 .- 1768-3254. ; 42, s. 276-285
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Tidskriftsartikel (refereegranskat)abstract
- A 30-membered library of amides based on the potent urotensin II (UII) receptor agonist FL104, has been synthesized from ten different carboxylic acids and three amines. A synthetic protocol producing the amides in 47-98% yield has been developed in which the purification involved only extractions and in a few cases filtration through an ion-exchange resin. It was found that 5 mg of starting material was enough to obtain reproducible results and excellent purities. Thus, the procedure is estimated to be transferable to fully automated systems. The synthesized compounds were evaluated for their UII receptor agonistic activities using a cell-based assay (R-SAT). The most active compounds were the 4-trifluoromethylcinnamic amides of 1-(4-chlorophenyl)-3-dimethylamino-propylamine and 1-(2-naphthyl)-3-dimethylamino-propylamine, both showed EC50 values of 130 nM. © 2006 Elsevier Masson SAS. All rights reserved.
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| 8. |
- Lehmann, Fredrik, 1976, et al.
(författare)
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Isochromanone-based urotensin-II receptor agonists.
- 2005
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Ingår i: Bioorganic & medicinal chemistry. - : Elsevier BV. - 0968-0896. ; 13:8, s. 3057-68
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Tidskriftsartikel (refereegranskat)abstract
- A series of analogues of the selective non-peptide urotensin II (UII) receptor agonist 3-(4-chlorophenyl)-3-(2-dimethylaminoethyl)-isochroman-1-one (AC-7954, 1) was synthesized and evaluated for UII agonist activity using a functional cell-based assay. The introduction of a methyl group in the 4-position resulted in a complete loss of activity, whereas substituents in the aromatic rings were beneficial. Sterically demanding amino groups were also detrimental to the activity. Several potent agonists were identified, six compounds being equally or more potent than 1. The most potent compound in the series was the 6,7-dimethyl analogue of 1 (16, pEC50 6.87). The racemate of 16 was resolved into the pure enantiomers using preparative straight phase HPLC. It was shown that the potency resides in the (+)-enantiomer (pEC50 7.11). The synthesized compounds seem to be selective for the UII receptor as no activities were observed at the closely related SSTR3 and 5 receptors.
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| 9. |
- Lehmann, Fredrik, 1976, et al.
(författare)
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Novel and potent small-molecule urotensin II receptor agonists
- 2009
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Ingår i: Bioorganic & Medicinal Chemistry. - : Elsevier BV. - 0968-0896. ; 17:13, s. 4657-4665
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Tidskriftsartikel (refereegranskat)abstract
- A series of analogs of the non-peptidic urotensin II receptor agonist N-[1-(4-chlorophenyl)-3-(dimethylamino)propyl]-4-phenylbenzamide (FL104) has been synthesized and evaluated pharmacologically. The enantiomers of the two most potent racemic analogues were obtained from the corresponding diastereomeric mandelic amides. In agreement with previously observed SAR, most of the agonist potency resided in the (S) enantiomers. The most potent UII receptor agonist in the new series was (S)-N-[3-dimethylamino-1-(2-naphthyl)propyl]-4-(4-chlorophenyl)benzamide (EC50 = 23 nM at the urotensin II receptor).
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| 10. |
- Lehmann, Fredrik, 1976, et al.
(författare)
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Novel potent and efficacious nonpeptidic urotensin II receptor agonists
- 2006
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 49, s. 2232-2240
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Tidskriftsartikel (refereegranskat)abstract
- Six different series of nonpeptidic urotensin II receptor agonists have been synthesized and evaluated for their agonistic activity in a cell-based assay (R-SAT). The compounds are ring-opened analogues of the isochromanone-based agonist AC-7954 with different functionalities constituting the linker between the two aromatic ring moieties. Several of the compounds are highly potent and efficacious, with N-[1-(4-chlorophenyl)-3-(dimethylamino)- propyl]-4-phenylbenzamide oxalate (5d) being the most potent. The pure enantiomers of 5d were obtained from the corresponding diastereomeric amides. It was shown by a combination of X-ray crystallography and chemical correlation that the activity resides in the S-enantiomer of 5d (pEC50 7.49). © 2006 American Chemical Society.
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| 11. |
- Nilsson, Erika, et al.
(författare)
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Effects of stream predator richness on the prey community and ecosystem attributes.
- 2008
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Ingår i: Oecologia. - : Springer Science and Business Media LLC. - 1432-1939 .- 0029-8549. ; 157:4, s. 641-651
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Tidskriftsartikel (refereegranskat)abstract
- It is important to understand the role that different predators can have to be able to predict how changes in the predator assemblage may affect the prey community and ecosystem attributes. We tested the effects of different stream predators on macroinvertebrates and ecosystem attributes, in terms of benthic algal biomass and accumulation of detritus, in artificial stream channels. Predator richness was manipulated from zero to three predators, using two fish and one crayfish species, while density was kept equal (n = 6) in all treatments with predators. Predators differed in their foraging strategies (benthic vs. drift feeding fish and omnivorous crayfish) but had overlapping food preferences. We found effects of both predator species richness and identity, but the direction of effects differed depending on the response variable. While there was no effect on macroinvertebrate biomass, diversity of predatory macroinvertebrates decreased with increasing predator species richness, which suggests complementarity between predators for this functional feeding group. Moreover, the accumulation of detritus was affected by both predator species richness and predator identity. Increasing predator species richness decreased detritus accumulation and presence of the benthic fish resulted in the lowest amounts of detritus. Predator identity (the benthic fish), but not predator species richness had a positive effect on benthic algal biomass. Furthermore, the results indicate indirect negative effects between the two ecosystem attributes, with a negative correlation between the amount of detritus and algal biomass. Hence, interactions between different predators directly affected stream community structure, while predator identity had the strongest impact on ecosystem attributes.
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| 12. |
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| 13. |
- Nilsson, Erika, et al.
(författare)
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Facilitation and interference among three predators affect their consumption of a stream-dwelling mayfly
- 2006
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Ingår i: Freshwater Biology. - : Wiley. - 0046-5070 .- 1365-2427. ; 51:8, s. 1507-1514
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Tidskriftsartikel (refereegranskat)abstract
- 1. We experimentally tested if a multiplicative risk model accurately predicted the consumption of a common mayfly at risk of predation from three predator species in New Zealand streams. Deviations between model predictions and experimental observations were interpreted as indicators of ecologically important interactions between predators. 2. The predators included a drift-feeding fish [brown trout (T), Salmo trutta], a benthivorous fish [galaxiid (G), koaro, Galaxias brevipennis] and a benthic predatory stonefly (S; Stenoperla sp.) with Deleatidium sp. mayflies as prey. Eight treatments with all predator species combinations and a predator-free control were used. Experiments were performed in aquaria with cobbles as predator refuges for mayflies and we measured the proportion of prey consumed after 6 h for both day and night trials. 3. Trout consumed a higher proportion of prey than other predators. For the two predator treatments we found less than expected prey consumption in the galaxiid + trout treatment (G + T) for both day and night trials, whereas a higher than expected proportion of prey was consumed during night time in the stonefly + trout (S + T) treatment. 4. The results indicate interference (G + T) and facilitation (S + T) between predators depending on predator identity and time of day. Thus, to make accurate predictions of interspecific interactions, it is necessary to consider the ecology of individual species and how differences influence the direction and magnitude of interactions.
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| 14. |
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| 15. |
- Olsson, Karin, et al.
(författare)
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The influence of food quality and availability on trophic position, carbon signature, and growth rate of an omnivorous crayfish
- 2008
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Ingår i: Canadian Journal of Fisheries and Aquatic Sciences. - 1205-7533. ; 65:10, s. 2293-2304
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Tidskriftsartikel (refereegranskat)abstract
- Fourteen sites in 13 streams were surveyed to address the importance of food quality and quantity on trophic position, carbon signature, and growth rate of noble crayfish (Astacus astacus) by combining the analyses of gut content, stable isotopes, and RNA-DNA ratio. The gut content analysis showed an omnivorous feeding habit, but total animal food sources contributed more to the nitrogen and carbon isotope signals of this species. The biomass of invertebrates (i.e., high quality food) influenced the trophic position, carbon signature, and growth rate. Our results show that crayfish in streams with a high biomass of invertebrates were at a higher trophic position and had a higher growth rate than crayfish in streams with a low biomass of invertebrates. A high biomass of relatively sedentary invertebrates indicates a habitat with high algae biomass, which is reflected in the more autochthonous carbon signature of crayfish. Further, noble crayfish in temperate streams seem to have dual functional roles by acting as predator and as shredder by processing large amounts of detritus.
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| 16. |
- Olsson, Mats J., et al.
(författare)
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Odor Memory Performance and Memory Awareness : A Comparison to Word Memory Across Orienting Tasks and Retention Intervals
- 2009
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Ingår i: Chemosensory Perception. - : Springer Science and Business Media LLC. - 1936-5802 .- 1936-5810. ; 2:3, s. 161-171
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Tidskriftsartikel (refereegranskat)abstract
- Odor memory has been argued to exhibit unique characteristics in relation to memory for other types of stimuli such as visually presented words. Two experiments investigated episodic recognition performance as well as memory awareness for odors and words across manipulations of orienting task and retention interval. Orienting task mattered little to odor recognition. However, in contradiction with several previous studies, substantial forgetting of odors was found. After controlling for effects of odor identifiability, it was found that memory for identified odors exhibited greater similarities to memory for words than to memory for unidentified odors.
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