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- Andersson, Christin, et al.
(författare)
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In vivo and in vitro lipidation of recombinant immunogens for direct iscom incorporation
- 2001
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Ingår i: Journal of Immunological Methods. - 0022-1759. ; 255:1-2, s. 135-148
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Tidskriftsartikel (refereegranskat)abstract
- We have previously reported strategies for Escherichia coli production of recombinant immunogens fused to hydrophobic tags to improve their capacity to be incorporated into an adjuvant formulation (J. Immunol. Methods 222 (1999) 171; 238 (2000) 181). Here, we have explored the possibility to use in vivo or in vitro lipidation of recombinant immunogens as means to achieve iscom incorporation through hydrophobic interaction. For the in vivo lipidation strategy, a general expression vector was constructed encoding a composite tag consisting of a sequence (lpp) of the major lipoprotein of E. coli, fused to a dual affinity fusion tag to allow efficient recovery by affinity chromatography. Upon expression in E. coli, fatty acids would be linked to the produced gene products. To achieve in vitro lipidation, the target immunogen would be expressed in frame with an N-terminal His6-ABP affinity tag, in which the hexahistidyl tag was utilized to obtain lipidation via a Cu2+-chelating lipid. A 238 amino acid segment ΔSAG1, from the central region of the major surface antigen SAG1 of Toxoplasma gondii, served as model immunogen in this study. The two generated fusion proteins, lpp-His6-ABP-ΔSAG1 and His6-ABP-ΔSAG1, both expressed at high levels (approximately 5 and 100 mg/l, respectively), could be recovered to high purity by ABP-mediated affinity chromatography, and were evaluated in iscom-incorporation experiments. The His6-ABP-ΔSAG1 fusion protein was associated to iscom matrix with pre-incorporated chelating lipid. Both fusion proteins were found in the iscom fractions after analytical ultracentrifugation in a sucrose gradient, indicating successful iscom incorporation/association. Iscom formation was further supported by electron microscopy analysis. In addition, these iscom preparations were demonstrated to induce high-titer antigen-specific antibody responses upon immunization of mice. For this particular target immunogen, ΔSAG1, the induced antibodies demonstrated poor reactivity to the native antigen, although slightly better for the preparation employing the in vitro lipidation strategy, indicating that ΔSAG1 was suboptimally folded or presented. Nevertheless, we believe that the presented strategies offer convenient alternative ways to achieve efficient adjuvant incorporation for recombinant immunogens.
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| 3. |
- Ansebo, L., et al.
(författare)
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Antennal and behavioural response of codling moth Cydia pomonella to plant volatiles
- 2004
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Ingår i: Journal of applied entomology. - : Wiley. - 0931-2048 .- 1439-0418. ; 128:7, s. 488-493
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Tidskriftsartikel (refereegranskat)abstract
- Identification of host volatile compounds attractive to codling moth Cydia pomonella, a most important insect of apple, will contribute to the development of safe control techniques. Synthetic apple volatiles in two doses were tested for antennal and behavioural activity in codling moth. Female antennae strongly responded to (Z)3-hexenol, (Z)3-hexenyl benzoate, (Z)3-hexenyl hexanoate, (+/-)-linalool and E,E-alpha-farnesene. Two other compounds eliciting a strong antennal response were the pear ester, ethyl (E,Z)-2,4-decadienoate, and its corresponding aldehyde, E,E-2,4-decadienal, which is a component of the larval defence secretion of the European apple sawfly. Attraction of codling moth to compounds eliciting a strong antennal response was tested in a wind tunnel. Male moths were best attracted to a blend of (E,E)-alpha-farnesene, (E)-beta-farnesene and ethyl (E,Z)-2,4-decadienoate. The aldehyde E,E-2,4-decadienal had an antagonistic effect when added to the above mixture.
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- Aspegren Kendall, Sally, 1950-, et al.
(författare)
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Differences in sensory thresholds in the skin of women with fibromyalgia syndrome : A comparison between ketamine responders and ketamine non-responders
- 2003
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Ingår i: Journal of Musculoskeletal Pain. - 1058-2452 .- 1540-7012. ; 11:2, s. 3-9
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To compare detection and pain thresholds in the skin of female fibromyalgia patients who were either ketamine responders or ketamine nonresponders.Methods: Detection thresholds to innocuous warmth, of cold, heat or cold pain, and touch and dynamic touch sensation were determined in the skin. Pressure pain thresholds, local and widespread pain intensity, and pain duration were also registered.Results: Ketamine nonresponse was associated with more pronounced hypersensitivity for thermal pain [especially cold pain] than ketamine response.Conclusions: Blockade of N-metyl-D-aspartic acid receptors by ketamine and the recording of pain thresholds in the skin, especially for cold pain, might reveal different mechanisms of allodynia.
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- Azerkan, Leila, et al.
(författare)
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Characterization of oxyntic glands isolated from the rat gastric mucosa
- 2001
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Ingår i: Comparative Biochemistry and Physiology A. - 1095-6433 .- 1531-4332. ; 128:2, s. 349-357
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Tidskriftsartikel (refereegranskat)abstract
- A simple and reproducible method for isolating oxyntic glands from the rat gastric mucosa was developed. The mucosa was incubated with pronase and EGTA, and then treated mechanically to release glands that were separated from single cells by sedimentation. Parietal cells were identified by immunostaining using a monoclonal antibody against H,K-ATPase. The glandular cells appeared morphologically intact. By careful control of the conditions of gland isolation, long glandular structures comprising hundreds of cells surrounding the lumen were obtained. Intraperitoneal injection of Br-deoxyuridine in the rat 1.5 h before the isolation procedure resulted in glands with a labeling of cells in their neck region. The glands were viable, as demonstrated by their ability to respond to various hormones. Histamine dose-dependently stimulated the acid formation which was measured as the accumulation of [14C]aminopyrine. At 100 microM histamine the accumulation was increased 5-10-fold. At 100 nM, pentagastrin potentiated the histamine stimulated accumulation by approximately 40% but pentagastrin alone did not stimulate. The oxyntic glands obtained by the present procedure appear useful for studies on cell physiology, including regulation of acid secretion, cellular interactions, and possibly also differentiation and proliferation mechanisms since long glandular fragments that contained the proliferative zone could be isolated.
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| 6. |
- Backman, A. C., et al.
(författare)
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Volatiles from apple (Malus domestica) eliciting antennal responses in female codling moth Cydia pomonella (L.) (Lepidoptera : Tortricidae): Effect of plant injury and sampling technique
- 2001
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Ingår i: Zeitschrift für Naturforschung C - A Journal of Biosciences. - : Walter de Gruyter GmbH. - 0939-5075 .- 1865-7125. ; 56:04-mar, s. 262-268
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Tidskriftsartikel (refereegranskat)abstract
- The antennal responses of codling moth females, Cydia pomonella, to volatiles from apple branches with green fruits were recorded by electroantennography coupled to gas chromatography. The antennae strongly responded to 4,8-dimethyl-1,3(E),7-nonatriene, linalool, beta -caryophyllene, (E)-beta -farnesene, germacrene D, (Z,E)-alpha -farnesene, (E,E)-alpha -farnesene and methyl salicylate. These compounds were all present in volatile collections on Porapak Q from both living and cut branches. Analysis by the solid phase microextraction technique (SPME) showed that the emission of some electrophysiologically active compounds increased after branches had been cut, especially 4,8-dimethyl-1,3(E),7-nonatriene, linalool and (E,E)-alpha -farnesene. The identification of apple volatiles eliciting antennal responses is the first step towards the identification of compounds mediating host-finding and oviposition in codling moth females.
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| 7. |
- Bekele, Tesfaye
(författare)
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Plant Population Dynamics of Dodonaea angustifolia and Olea europaea ssp. cuspidata in Dry Afromontane Forests of Ethiopia
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Human disturbance has led to excessive deforestation and to a very limited forest cover in the Afromontane zone of Ethiopia, which forms a large part of the country. Thus urgent conservation measures are required to ameliorate the situation. Understanding the natural regeneration processes and the dynamics of plant populations of tree and shrub species has a practical application in the restoration of these habitats.The present study focuses on the population dynamics and regeneration of an early successional shrub Dodonaea angustifolia and a late successional tree Olea europaea ssp. cuspidata in southern Wello, Ethiopia. Population structure and dynamics, regeneration and seed banks in dry Afromontane habitats were considered.For both species, three population structure patterns were identified: 1) high density, reversed J-shape structure with many seedlings and few large individuals, 2) lower density, unimodal structure with higher proportions of plants of intermidiate size, 3) high density with higher proportions of large plants , in some cases bimodal with small and large individuals. Vegetation type and protection time were found to have a significant effect on the population structure of both species. Dodonaea can establish itself on degraded land, once the disturbance has ceasedProjection matrix analysis on observations from permanent plots in Dodonaea populations in protected and unprotected sites resulted in one declining population, and one increasing in the protected site and declining populations at the unprotected site. The overall projected growth rate in Dodonaea calculated from a pooled matrix indicated positive population growth. The factors influencing the population growth, recruitment and survival are discussed.The persistence of Olea populations seems to depend on the more stable environmental conditions in later successional stages of forest vegetation. There are possibilities of natural regeneration of Olea if regenerating individuals still occur in the area. Rainfall seasonality is a dominant factor in regulating establishment, recruitment, survival and growth, particularly during the seedling stage. Moreover, shade and herbivory are factors that need consideration. Since Olea grows better under shade than in the open sun, successful regeneration for this species relies on shade from other plants and on protection from grazing, at least during the seedling stage.Most of the species that germinated from the seed banks were herbs and grasses with very few shrub and tree species. There was low correspondence between species composition of the seed banks and that of the standing vegetation.Spatial and temporal variation in demographic parameters among populations of Dodonaea and Olea can be attributed to human and environmental influence. Under protection, both Dodonaea and Olea seem to have a possibility to regenerate naturally. Further research should consider factors mentioned in detailed investigations of other dominant Afromontane forest species.
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