| 1. |
- Andersson, Anders, et al.
(författare)
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A transcriptional timetable of autumn senescence
- 2004
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Ingår i: Genome Biology. - : Springer Science and Business Media LLC. - 1465-6906 .- 1474-760X. ; 5:4, s. R24-
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Tidskriftsartikel (refereegranskat)abstract
- Background We have developed genomic tools to allow the genus Populus (aspens and cottonwoods) to be exploited as a full-featured model for investigating fundamental aspects of tree biology. We have undertaken large-scale expressed sequence tag (EST) sequencing programs and created Populus microarrays with significant gene coverage. One of the important aspects of plant biology that cannot be studied in annual plants is the gene activity involved in the induction of autumn leaf senescence. Results On the basis of 36,354 Populus ESTs, obtained from seven cDNA libraries, we have created a DNA microarray consisting of 13,490 clones, spotted in duplicate. Of these clones, 12,376 (92%) were confirmed by resequencing and all sequences were annotated and functionally classified. Here we have used the microarray to study transcript abundance in leaves of a free-growing aspen tree (Populus tremula) in northern Sweden during natural autumn senescence. Of the 13,490 spotted clones, 3,792 represented genes with significant expression in all leaf samples from the seven studied dates. Conclusions We observed a major shift in gene expression, coinciding with massive chlorophyll degradation, that reflected a shift from photosynthetic competence to energy generation by mitochondrial respiration, oxidation of fatty acids and nutrient mobilization. Autumn senescence had much in common with senescence in annual plants; for example many proteases were induced. We also found evidence for increased transcriptional activity before the appearance of visible signs of senescence, presumably preparing the leaf for degradation of its components.
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| 2. |
- Bümming, Per, 1965, et al.
(författare)
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Neoadjuvant, adjuvant and palliative treatment of gastrointestinal stromal tumours (GIST) with imatinib: a centre-based study of 17 patients.
- 2003
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Ingår i: British journal of cancer. - : Springer Science and Business Media LLC. - 0007-0920 .- 1532-1827. ; 89:3, s. 460-4
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Tidskriftsartikel (refereegranskat)abstract
- Malignant gastrointestinal stromal tumours (GIST) have a poor prognosis. Since these tumours are resistant to conventional radiation and chemotherapy, surgery has been the mainstay of treatment. However, surgery is usually inadequate for the treatment of malignant GIST. Imatinib, a KIT tyrosine kinase inhibitor, has recently been found to have a dramatic antitumour effect on GIST. In this centre-based study of 17 consecutive patients with high-risk or overtly malignant GIST, imatinib was used in three different settings - palliatively, adjuvantly, and neoadjuvantly. The treatment was found to be safe and particularly effective in tumours with activating mutations of exon 11 of the KIT gene. Clinical response to imatinib treatment correlated morphologically to tumour necrosis, hyalinisation, and reduced proliferative activity. The value of neoadjuvant imatinib treatment was illustrated in one case.
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| 5. |
- Movérare, Sofia, et al.
(författare)
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Estren is a selective estrogen receptor modulator with transcriptional activity.
- 2003
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Ingår i: Molecular pharmacology. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 0026-895X .- 1521-0111. ; 64:6, s. 1428-33
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Tidskriftsartikel (refereegranskat)abstract
- It was recently reported that the synthetic compound estren increases bone mass without affecting reproductive organs or classic transcription. The aim of the present study was to further characterize the in vivo and in vitro effects of estren. We demonstrate that estren is a selective estrogen receptor modulator (SERM) with a strong effect on thymus, a moderate effect on uterus and trabecular bone, but no major effect on fat or cortical bone in 11-month-old ovariectomized mice. The effect of estren on trabecular bone and uterus is mediated via estrogen receptors (ERs) because no effect is seen in ER double-inactivated mice. Furthermore, with the use of ERalpha- and ERbeta-expressing reporter cell lines, we demonstrate that estren displays an agonistic effect on transcriptional activity of an estrogen-responsive element-driven reporter gene with a degree of agonism similar to that of 17beta-estradiol for both ERalpha and ERbeta. Thus, estren has the capacity to exert genomic effects via both ERalpha and ERbeta. We conclude, in contrast to what was previously reported by others, that estren is a SERM with transcriptional activity.
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| 6. |
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| 7. |
- Nilsson, Johanna, 1961
(författare)
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A survey of the most common support methods used on historical costumes and a preliminary investigation of tests assessing the quality of conserved fabrics.
- 2004
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Ingår i: Publicerad i postprint för konferensen “Scientific analysis of ancient and historic textiles, 2004, vid universitet i Southampton..
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT The aim of this study was to find ways of evaluating support methods used in textile conservation. A questionnaire completed by workshops in Sweden and abroad served to identify the most commonly used method of costume support and the main criteria used in determining the success of a conservation treatment. The most common method is for a support to be inserted between the outer fabric and lining and sewn on by laid thread couching. The most important conservation requirements are for the results to be aesthetically attractive and to provide good support.Standard weave silk and woollen fabrics were aged and then conserved using the above method. Five different mechanicaltesting procedures were then performed corresponding to the different stresses a costume might suffer: abrasion resistance,flexometer abrasion, flexometer bending, shear stiffness and tensile strength. The methods for abrasion resistance and tensile strength testing proved to be suitable to allow a comparison between different methods of support. Firmer significant conclusions, however, require a larger corpus of material.
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| 8. |
- Nilsson, Johanna
(författare)
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Molecular mechanisms of local anaesthetic action on voltage-gated ion channels
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis I try to clarify some molecular mechanisms of local anaesthetic action on ion channels. The traditional view is that local anaesthetics eliminate action potentials by a direct block of Na channels. Other mechanisms, however, have been suggested. For instance bupivacaine has been proposed to affect Na channels in myelinated axons indirectly, by making the resting potential less negative. To test this hypothesis we analysed the effects of bupivacaine on voltage-clamped myelinated axons from Xenopus laevis. Contrary to the suggested hypothesis, the leak current and the resting potential were unaffected. Furthermore, the blocking effect on the K current was explained by two population-specific mechanisms. In order to gain further insights in the molecular mechanisms of local anaesthetic action, we analyzed the effects of bupivacaine on a series of voltage-gated K (Kv) channels and various mutant channels, expressed in Xenopus oocytes. Two phenomenologically different blocking effects were seen; a timedependent block of Kv1 and Kv3 channels, and a time independent block on Kv2.1. Swapping the S6 helix between Kv1.2 and Kv2.1 introduced Kv1.2 features into Kv2.1. The results suggest that bupivacaine blocks Kv channels by an open-state dependent mechanism, and that Kv2.1 deviates from the other channels in allowing a partial closure of the bupivacaine-bound channel. The results also suggest that the binding site in Kv2.1 is located in the internal vestibule and that residues in the descending P-loop and the upper part of S6 are critical for the binding. The location of the binding sites was further investigated by automated docking and molecular dynamics methods, using homology models of Kv1.5. Two different models were constructed to describe an open channel. They were based on the crystallized bacterial channels KcsA and MthK. The first model corresponds to a PVP-type of bending hinge in the internal helices, while the second corresponds to a Gly-type of bending hinge. The automated docking and molecular dynamics calculations combined with free energy estimations predicted strongest binding to the PVP region. Surprisingly, no binding was predicted for the Gly-bend model. The results support our electrophysiological data showing that Kv1.5 is unable to close when bupivacaine is bound to the channel. The standard view of local anaesthetic action assumes a preferential binding to channels in inactivated state. Recently, this view has been challenged. We investigated this issue by comparing the effects of bupivacaine on inactivating and non-inactivating Kv channels of similar subtypes, hypothesizing that the bupivacaine affinity is similar for the two types due to the structural similarities. The results can be explained by a simple kinetic scheme, deviating from the standard scheme in assuming local anaesthetic binding to channels exclusively in open state. By using data from Na channel experiments we could in simulations show that the basic scheme could be used to clarify controversial issues about local anaesthetic effects on Na channel inactivation.
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| 9. |
- Pedersen, Karsten, 1952, et al.
(författare)
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Distribution, diversity and activity of microorganisms in the hyper-alkaline spring waters of Maqarin in Jordan
- 2004
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Ingår i: Extremophiles. - : Springer Science and Business Media LLC. - 1431-0651 .- 1433-4909. ; 8:2, s. 151-164
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Tidskriftsartikel (refereegranskat)abstract
- The hyper-alkaline, high-Ca2+ springs of Maqarin, Jordan, were investigated as an analogue for various microbial processes at the extremely high pH generated by cement and concrete in some underground radioactive waste repositories. Leaching of metamorphic, cementitious phases in Maqarin has produced current, hyper-alkaline groundwater with a maximum pH of 12.9. Six consecutive expeditions were undertaken to the area during 19942000. The total number of microorganisms in the alkaline waters was 103105 cells/ml. Analysis of the 16S-ribosomal ribonucleic acid (rRNA) diversity revealed microorganisms mainly belonging to the Proteobacteria. Obvious similarities between the obtained sequences and sequences from other alkaline sites could not be found. Numerous combinations of culture media compositions were inoculated with spring, seepage and groundwaters and incubated under aerobic and anaerobic conditions with various carbon sources. Assimilation studies were performed using identical radio-labeled carbon sources. Glucose seemed to be the preferred carbon source for assimilation, followed by acetate, lactate, and leucine. The results demonstrate that microorganisms from the hyper-alkaline springs of Maqarin could grow and be metabolically active under aerobic and anaerobic hyper-alkaline conditions. However, the growth and activity found were not vigorous; instead, slow growth, low numbers, and a generally low metabolic activity were found. This suggests that microbial activity will be low during the hyper-alkaline phase of cementitious repositories
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| 10. |
- Yregård, Liselotte, et al.
(författare)
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A new technique for the analysis of endogenous mediators released following thermal injury.
- 2001
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Ingår i: Burns : journal of the International Society for Burn Injuries. - 0305-4179. ; 27:1, s. 9-16
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Tidskriftsartikel (refereegranskat)abstract
- Few techniques today enable us to measure the complex processes taking place inside a burn wound in vivo. The present in vivo technique was based on a standardised burn model in rat skin. A partial- or full-thickness burn was induced and resulted in a gelatinous oedema located between the skin and the underlying rectus muscle. The oedema has distinct borders to the surrounding connective tissue and is separated and removed easily for further analysis. Myeloperoxidase (MPO) activity used as indicator of neutrofil infiltration was increased significantly in the burn oedema versus non-burned skin. Leukocyte metabolic activity was high as shown by significantly higher free radical formation (ESR) in the oedema than in surrounding burned and non-burned tissue. Leukocyte viability measured by Trypan blue stain was 70% in the oedema of full-thickness burns. In order to decide whether processes taking place in the oedema communicate freely with systemic circulation, we conducted a number of experiments. Results show in burned animals in vivo that intravenous administration of indomethacin induced a strong inhibition of PGE(2) in the burn oedema as compared with saline but, as expected, had no significant effect on LTB(4) synthesis. In conclusion, the present technique allows us to analyse the processes taking place inside the burn wound in vivo and to evaluate the effects of various agents on these processes.
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