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- 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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| 4. |
- 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. |
- Hederus, Sanna, et al.
(författare)
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Keramiska väggmaterial i offentlig miljö : Forskningsrapport
- 2004
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Ett konstnärligt forskningsprojekt inom ramen för KRC (Keramiskt Resurscentrum) på Konstfack, med utgångspunkt i Stockholms tunnelbana. Projektets målsättning har varit att bedriva en praktisk och teoretisk forskning kring design och keramiska materials användning i offentlig miljö. Projektet är utformat som ett tvärvetenskapligt samarbete mellan deltagarna i projektgruppen. I projektgruppen ingår; Sanna Hederus, arkitekt Johanna Karlin, konstnär Gustaf Nordenskiöld, keramiker Anna Westholm, industridesigner Projektledare och redaktörer; Katarina Andersson och Helena Holmberg Projektet har möjliggjorts genom ett samarbete med SL, CC Höganäs, Gatu- och Fastighetskontoret i Stockholms kommun och Byggkeramikrådet.
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| 6. |
- Macvanin, Mirjana, et al.
(författare)
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Fusidic acid-resistant mutants of Salmonella enterica serovar Typhimurium with low fitness in vivo are defective in RpoS induction
- 2003
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Ingår i: Antimicrobial Agents and Chemotherapy. - 0066-4804 .- 1098-6596. ; 47:12, s. 3743-3749
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Tidskriftsartikel (refereegranskat)abstract
- Mutants of Salmonella enterica serovar Typhimurium resistant to fusidic acid (Fusr) have mutations in fusA, the gene encoding translation elongation factor G (EF-G). Most Fusr mutants have reduced fitness in vitro and in vivo, in part explained by mutant EF-G slowing the rate of protein synthesis and growth. However, some Fusr mutants with normal rates of protein synthesis still suffer from reduced fitness in vivo. As shown here, Fusr mutants could be similarly ranked in their relative fitness in mouse infection models, in a macrophage infection model, in their relative hypersensitivity to hydrogen peroxide in vivo and in vitro, and in the amount of RpoS production induced upon entry into the stationary phase. We identify a reduced ability to induce production of RpoS (sigmas) as a defect associated with Fusr strains. Because RpoS is a regulator of the general stress response, and an important virulence factor in Salmonella, an inability to produce RpoS in appropriate amounts can explain the low fitness of Fusr strains in vivo. The unfit Fusr mutants also produce reduced levels of the regulatory molecule ppGpp in response to starvation. Because ppGpp is a positive regulator of RpoS production, we suggest that a possible cause of the reduced levels of RpoS is the reduction in ppGpp production associated with mutant EF-G. The low fitness of Fusr mutants in vivo suggests that drugs that can alter the levels of global regulators of gene expression deserve attention as potential antimicrobial agents.
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| 7. |
- 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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| 8. |
- Nagaev, Ivan, et al.
(författare)
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Biological cost and compensatory evolution in fusidic acid-resistant Staphylococcus aureus
- 2001
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Ingår i: Molecular Microbiology. - : BLACKWELL SCIENCE LTD. - 0950-382X .- 1365-2958. ; 40:2, s. 433-439
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Tidskriftsartikel (refereegranskat)abstract
- Fusidic acid resistance resulting from mutations in elongation factor G (EF-G) of Staphylococcus aureus is associated with fitness costs during growth in vivo and in vitro. In both environments, these costs can be partly or fully compensated by the acquisition of secondary intragenic mutations. Among clinical isolates of S. aureus, fusidic acid-resistant strains have been identified that carry multiple mutations in EF-G at positions similar to those shown experimentally to cause resistance and fitness compensation. This observation suggests that fitness-compensatory mutations may be an important aspect of the evolution of antibiotic resistance in the clinical environment, and may contribute to a stabilization of the resistant bacteria present in a bacterial population.
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