| 1. |
- Henriksson, Gunnar, 1965-, et al.
(författare)
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Monocomponent endoglucanases : an excellent tool in wood chemistry and pulp processing
- 2005
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Ingår i: 13th ISWFPC (International Symposium on Wood, Fibre and Pulping Chemistry), Auckland, New Zealand, 16-19 May 2005: Proceedings. ; , s. 503-508
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Konferensbidrag (refereegranskat)abstract
- Highly pure cellulases of endoglucanase type produced by genetically modified fungi are commercially available. They are useful tools both for analytical wood chemistry and potentially also as industrial chemicals for novel processes for the pulp and paper industry. Here the functionality of cellulases and some application of endoglucanases are reviewed. The mechanisms behind the effects of the enzyme are discussed.
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| 2. |
- Andersson, Ulrika, et al.
(författare)
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MNS16A minisatellite genotypes in relation to risk of glioma and meningioma and to glioblastoma outcome.
- 2009
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Ingår i: International journal of cancer. Journal international du cancer. - : Wiley. - 1097-0215 .- 0020-7136. ; 125:4, s. 968-972
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Tidskriftsartikel (refereegranskat)abstract
- The human telomerase reverse transcriptase (hTERT) gene is upregulated in a majority of malignant tumours. A variable tandem repeat, MNS16A, has been reported to be of functional significance for hTERT expression. Published data on the clinical relevance of MNS16A variants in brain tumours have been contradictory. The present population-based study in the Nordic countries and the United Kingdom evaluated brain-tumour risk and survival in relation to MNS16A minisatellite variants in 648 glioma cases, 473 meningioma cases and 1,359 age, sex and geographically matched controls. By PCR-based genotyping all study subjects with fragments of 240 or 271 bp were judged as having short (S) alleles and subjects with 299 or 331 bp fragments as having long (L) alleles. Relative risk of glioma or meningioma was estimated with logistic regression adjusting for age, sex and country. Overall survival was analysed using Kaplan-Meier estimates and equality of survival distributions using the log-rank test and Cox proportional hazard ratios. The MNS16A genotype was not associated with risk of occurrence of glioma, glioblastoma (GBM) or meningioma. For GBM there were median survivals of 15.3, 11.0 and 10.7 months for the LL, LS and SS genotypes, respectively; the hazard ratio for having the LS genotype compared with the LL was significantly increased HR 2.44 (1.56-3.82) and having the SS genotype versus the LL was nonsignificantly increased HR 1.46 (0.81-2.61). When comparing the LL versus having one of the potentially functional variants LS and SS, the HR was 2.10 (1.41-3.1). However, functionality was not supported as there was no trend towards increasing HR with number of S alleles. Collected data from our and previous studies regarding both risk and survival for the MNS16A genotypes are contradictory and warrant further investigations.
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| 3. |
- Barreto Henriksson, Helena, et al.
(författare)
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Identification of Cell Proliferation Zones, Progenitor Cells and a Potential Stem Cell Niche in the Intervertebral Disc Region: A Study in Four Species.
- 2009
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Ingår i: SPINE. - 0362-2436. ; 34:21, s. 2278-2287
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Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN.: Descriptive experimental study in 4 different mammals. OBJECTIVE.: To investigate cell proliferation/regeneration and localize stem cells/progenitor cells within the intervertebral disc (IVD). SUMMARY OF BACKGROUND DATA.: Disc degeneration (DD) is believed to play a major role in patients with chronic lumbar pain. Lately, biologic treatment options for DD have gained increasing interest. Normal regeneration processes within the IVD and have previously been sparsely described and therefore it is of great interest to increase the knowledge about these processes. METHODS.: Detection of cell proliferations zones and label-retaining cells were done by in vivo 5-bromo-2-deoxyuridine (BrdU) labeling in 18 rabbits, killed after 4, 6, 10, 14, 28, or 56 days. Results were visualized with immunohistochemistry and fluorescence/confocal microscopy. Localization of progenitor cell were further investigated by immunohistochemistry using antibodies towards Notch1, Delta4, Jagged1, C-KIT, KI67, and Stro-1 in normal IVD from rabbits (n = 3), rats (n = 2), minipigs (n = 2), and in human degenerated IVD (n = 4). Further, flowcytometry analysis using progenitor markers were performed on additional human IVD cells (n = 3). RESULTS.: BrdU positive cells were found in comparable numbers at early and late time points in most regions of the anulus fibrosus (AF) and nucleus pulposus demonstrating slow ongoing cell proliferation. In the AF border to ligament zone (AFo) and the perichondriumregion (P) a stem cell niche-like pattern was determined (a high number of BrdU positive cells at early time points vs. only a few label retaining cells at later time points). In normal and DD tissue from the 4 investigated species progenitor cell markers were detected. CONCLUSION.: The IVD is a tissue with ongoing slow cell proliferation both in the AF and the nucleus pulposus. The stem cell niche pattern detected in AFo and P can be suggested to play a role for IVD morphology and function. These findings may be of importance for the development of biologic treatment strategies. PMID: 19755937 [PubMed - as supplied by publisher]
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| 4. |
- Bethke, Lara, et al.
(författare)
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CASP8 D302H and meningioma risk : an analysis of five case-control series
- 2009
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Ingår i: Cancer Letters. - Clare : Elsevier. - 0304-3835 .- 1872-7980. ; 273:2, s. 312-315
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Tidskriftsartikel (refereegranskat)abstract
- Caspase 8 (CASP8) is a key regulator of apoptosis or programmed cell death, and hence a defence against cancer. The CASP8 polymorphism D302H has recently been shown to influence the risk of breast cancer. We tested the hypothesis that the CASP8 polymorphism D302H may influence risk of meningioma through analysis of five independent series of case patients and controls (n=631 and 637, respectively). Carrier status for 302H was not associated with a statistically significantly increased risk (OR=1.16; 95% CI: 0.87-1.53; P=0.31) making it unlikely that this variant contributes to the inherited risk of meningioma.
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| 5. |
- Bethke, Lara, et al.
(författare)
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Comprehensive analysis of DNA repair gene variants and risk of meningioma
- 2008
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Ingår i: Journal of the National Cancer Institute. - : Oxford University Press. - 0027-8874 .- 1460-2105. ; 100:4, s. 270-276
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Tidskriftsartikel (refereegranskat)abstract
- Background: Meningiomas account for up to 37% of all primary brain tumors. Genetic susceptibility to meningioma is well established, with the risk among relatives of meningioma patients being approximately threefold higher than that in the general population. A relationship between risk of meningioma and exposure to ionizing radiation is also well known and led us to examine whether variants in DNA repair genes contribute to disease susceptibility.Methods: We analyzed 1127 tagging single-nucleotide polymorphisms (SNPs) that were selected to capture most of the common variation in 136 DNA repair genes in five case–control series (631 case patients and 637 control subjects) from four countries in Europe. We also analyzed 388 putative functional SNPs in these genes for their association with meningioma. All statistical tests were two-sided.Results: The SNP rs4968451, which maps to intron 4 of the gene that encodes breast cancer susceptibility gene 1–interacting protein 1, was consistently associated with an increased risk of developing meningioma. Across the five studies, the association was highly statistically significant (trend odds ratio = 1.57, 95% confidence interval = 1.28 to 1.93; Ptrend = 8.95 × 10−6; P = .009 after adjusting for multiple testing).Conclusions: We have identified a novel association between rs4968451 and meningioma risk. Because approximately 28% of the European population are carriers of at-risk genotypes for rs4968451, the variant is likely to make a substantial contribution to the development of meningioma.
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| 6. |
- Bethke, Lara, et al.
(författare)
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Comprehensive analysis of the role of DNA repair gene polymorphisms on risk of glioma
- 2008
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Ingår i: Human Molecular Genetics. - : Oxford University Press. - 0964-6906 .- 1460-2083. ; 17:6, s. 800-805
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Tidskriftsartikel (refereegranskat)abstract
- Much of the variation in inherited risk of glioma is likely to be explained by combinations of common low risk variants. The established relationship between glioma risk and exposure to ionizing radiation led us to examine whether variants in the DNA repair genes contribute to disease susceptibility. We evaluated 1127 haplotype-tagging single-nucleotide polymorphisms (SNPs) supplemented with 388 putative functional SNPs to capture most of the common variation in 136 DNA repair genes, in five unique case–control series from four different countries (1013 cases, 1016 controls). We identified 16 SNPs associated with glioma risk at the 1% significance level. The highest association observed across the five independent case–control datasets involved rs243356, which maps to intron 3 of CHAF1A (trend odds ratio, 1.32; 95% confidence interval 1.14–1.54; P = 0.0002; false-positive report probability = 0.055, based on a prior probability of 0.01). Our results provide additional support for the hypothesis that low penetrance variants contribute to the risk of developing glioma and suggest that a genetic variant located in or around the CHAF1A gene contributes to disease risk.
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| 7. |
- Bethke, Lara, et al.
(författare)
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Functional polymorphisms in folate metabolism genes influence the risk of meningioma and glioma
- 2008
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Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - : American Association for Cancer Research (AACR). - 1055-9965 .- 1538-7755. ; 17:5, s. 1195-1202
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Tidskriftsartikel (refereegranskat)abstract
- Folate metabolism plays an important role in carcinogenesis. To test the hypothesis that polymorphic variation in the folate metabolism genes 5,10-methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTRR), and methionine synthase reductase (MTR) influences the risk of primary brain tumors, we genotyped 1,005 glioma cases, 631 meningioma cases, and 1,101 controls for the MTHFR C677A and A1298C, MTRR A66G, and MTR A2756G variants. MTHFR C677T-A1298C diplotypes were associated with risk of meningioma (P = 0.002) and glioma (P = 0.02); risks were increased with genotypes associated with reduced MTHFR activity. The highest risk of meningioma was associated with heterozygosity for both MTHFR variants [odds ratio (OR), 2.11; 95% confidence interval (95% CI), 1.42-3.12]. The corresponding OR for glioma was 1.23 (95% CI, 0.91-1.66). A significant association between risk of meningioma and homozygosity for MTRR 66G was also observed (OR, 1.41; 95% CI, 1.02-1.94). Our findings provide support for the role of folate metabolism in the development of primary brain tumors. In particular, genotypes associated with increased 5,10-methylenetetrahydrofolate levels are associated with elevated risk.
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| 8. |
- Bethke, Lara, et al.
(författare)
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The Common D302H Variant of CASP8 Is Associated with Risk of Glioma
- 2008
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Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - : American Association for Cancer Research (AACR). - 1055-9965 .- 1538-7755. ; 17:4, s. 987-989
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Tidskriftsartikel (refereegranskat)abstract
- Caspase 8 (CASP8) is a key regulator of apoptosis or programmed cell death, and, hence, a defense against cancer. We tested the hypothesis that the CASP8 polymorphism D302H influences risk of glioma through analysis of five series of glioma case patients and controls (n = 1,005 and 1,011, respectively). Carrier status for the rare allele of D302H was associated with a 1.37-fold increased risk (95% confidence interval, 1.10-1.70; P = 0.004). The association of CASP8 D302H with glioma risk indicates the importance of inherited variation in the apoptosis pathway in susceptibility to this form of primary brain tumor.
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| 9. |
- Bjurberg, Maria, et al.
(författare)
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Early changes in 2-deoxy-2-[18F]fluoro-D-glucose metabolism in squamous-cell carcinoma during chemotherapy in vivo and in vitro.
- 2009
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Ingår i: Cancer Biotherapy & Radiopharmaceuticals. - : Mary Ann Liebert Inc. - 1557-8852 .- 1084-9785. ; 24:3, s. 327-332
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Tidskriftsartikel (refereegranskat)abstract
- AIM: The aim of this study was to investigate early changes in uptake of 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) in vivo and in vitro in a squamous-cell carcinoma (SCC) cell line originating from a human head and neck SCC during cytotoxic therapy with respect to metabolism in tumor cells and in surrounding stromal tissue. MATERIALS AND METHODS: In 60 nude mice with xenografted SCC, 50 animals were treated with cisplatin. Early changes in the tumor FDG uptake following therapy were evaluated sequentially with phosphor imaging. Using this technique, areas with focal hypermetabolism were detected. The cells creating the focal hypermetabolism were then identified histopathologically on the corresponding sections. In addition, early FDG uptake versus the number of viable tumor cells was measured in vitro following cisplatin treatment. RESULTS: An early transient increase in FDG uptake in tumor cells was seen on day 1 in treated tumors, followed by a rapid decrease confirmed by subsequent tumor regression. This metabolic flare was present in all treated tumors but not in the controls. In vitro, an increase in FDG uptake per cell was observed. CONCLUSIONS: Our results provide new insights into the early metabolic changes in squamous-cell carcinomas subjected to cytotoxic therapy and thus contribute to the discussion on the feasibility of early predictive PET studies.
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| 10. |
- Brauner, A., et al.
(författare)
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Open-ended assignments and student responsibility
- 2007
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Ingår i: Biochemistry and molecular biology education. - : Wiley. - 1470-8175 .- 1539-3429. ; 35:3, s. 187-192
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Tidskriftsartikel (refereegranskat)abstract
- An inquiry-based laboratory course was created in an effort to increase student responsibility in learning and to improve teaching in areas related to molecular medicine. Authentic medical cases with both scientific and clinical aspects formed the basis of a project-oriented course that also included student laboratory work focused on the disease-related proteins. Students used basic biochemical techniques to develop and test hypotheses relating their results to the clinical findings. The course also included patient demonstrations to personalize students' knowledge of case presentations, lectures on basic biochemical principles relevant to the molecular basis of the cases, and seminars by invited guests with expertise in translational medicine. Students developed proposals for future research as part of the final examination. An inquiry matrix was used to evaluate the degree of learning responsibility taken during the course. By allowing for openness in how to explore the case including choice of methods and interpretation of unexpected results, students gained confidence in their ability to solve problems, formulate and test hypotheses, and collaborate with both clinical and non-clinical professionals.
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| 11. |
- Christiernin, Maria, et al.
(författare)
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Analysis of lignin isolated from poplar cell suspension cultures
- 2005
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Ingår i: 59th Appita Annual Conference and Exhibition, incorporating the 13th ISWFPC. ; , s. 81-86
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Konferensbidrag (refereegranskat)abstract
- We have investigated lignin structures in pure primary cell walls. Poplar cell suspension cultures, Populus tremula x tremuloides, were harvested after 7, 14 and 21 days of growth. Carbohydrate monomer analysis also points at the presence of primary wall exclusively. Confocal microscopy of the cells dyed with acriflavin demonstrates that lignin is present. Klason content increases during growth from 0.7 to 3.9 percent. GC analysis of samples subjected to thioacidolysis shows that the lignin constitutes of guaiacyl units as compared to poplar wood which have syringyl as the main monomer. The amount of monomers per unit Klason lignin is lower than in wood and it decreases during cultivation possibly indicating a larger relative content of carbon-carbon bonds in the polymeric lignin in the cell cultures as compared to wood. Five lignin structures were identified with massspectrometry.
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| 12. |
- Christiernin, Maria, et al.
(författare)
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Analysis of lignin isolated from spruce with secondary cell wall removed
- 2005
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Ingår i: 59th Appita Annual Conference and Exhibition, incorporating the 13th ISWFPC. ; , s. 73-79
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Konferensbidrag (refereegranskat)abstract
- Wood from white spruce, Picea glauca, that has been preserved by rapid burial in lake sediments 10 000 years ago was investigated and compared to fresh white spruce wood. The old sample has an intact outer cell wall and middle lamella but most of the secondary cell wall has been selectively removed by bacteria. Klason lignin content was found to be 60% in the old sample, more than twice as high as that found in normal wood. This was rather expected since the middle lamella and primary wall has a higher content of lignin than the secondary wall. After thioacidolysis of the samples the lignin monomer content in the old spruce was 9% lower than that of the reference wood, possibly due to more condensed lignin. This finding was supported by SEC analysis of the thioacidolysed samples. A small amount of coumaryl monomers, 3%, was found in the old spruce and none in the reference wood. The carbohydrate monomer distribution showed that galactose and arabinose and xylose content is higher in old spruce than in white spruce reference, and glucose content is 20% lower in old spruce as compared to reference white spruce. This confirms microscopical evidence that secondary wall was at least partially removed. No new oligomeric lignin structures could be identified with GC-MS analysis of the thioacidolysis products. Millwood lignin from samples were subjected to quantitative NMR analysis by combining 13 C and HSQC techniques, which showed that the lignin structures in mill wood lignin from the old spruce sample was almost identical to those of the reference wood.
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| 13. |
- Christiernin, Maria, et al.
(författare)
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Comparison between 10 000 year old and contemporary spruce lignin
- 2009
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Ingår i: Wood Science and Technology. - : Springer Science and Business Media LLC. - 0043-7719 .- 1432-5225. ; 43:1-2, s. 23-41
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Tidskriftsartikel (refereegranskat)abstract
- Wood from white spruce Picea glauca that had been preserved by rapid burial in lake sediments 10,000 years ago, was investigated and compared to a contemporary reference white spruce wood. The 10,000-year old sample appeared to have an intact primary cell wall and middle lamella, whereas the carbohydrate monomer distribution, and microscopic images showed that the secondary wall was at least partially removed, indicating that this structure had been selectively attacked by bacteria. The Klason lignin amount in the aged spruce was found to be 60%. The relative lignin monomer content in the aged spruce was 9% lower than that of the reference wood, showing that there were fewer beta-O-4' linkages in the aged sample. This finding was supported by SEC analysis of the thioacidolysed samples as a larger proportion of lignin oligomers were observed in the aged spruce than in the reference material. This indicates a somewhat greater number of condensed bonds in the aged spruce than in the reference spruce sample. Quantitative C-13 NMR analysis and HSQC techniques applied on milled wood lignins (MWL) revealed no significant structural differences between the aged spruce and the reference.
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| 14. |
- Christiernin, Maria, 1963-
(författare)
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Composition of lignin in outer cell-wall layers
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The composition of lignin in the outer cell-wall layers of spruce and poplar has been studied and the data obtained have been compared with those of the mature reference wood in which the secondary cell wall predominates. Materials with exclusively or predominantly outer cell-wall layers were examined. Accurate data relating to the lignin monomer composition and the number of β-O-4´ bonds were obtained from pure middle lamella/primary cell wall lignin. Firstly, a 10 000 year old white spruce material, with most of the secondary cell wall missing, was studied. The aged lignin was composed of guaiacyl units only, and was slightly more condensed but otherwise similar to the reference lignin.Secondly, the developing xylem of a Norway spruce clone was analyzed during a growth season. In spring and early summer, growth is very rapid and the intention was to sample tissues in which the secondary cell-wall layers had not yet lignified, but where the outer layers at least had started to lignify. Microscopy, Klason lignin and carbohydrate analyses showed that the lignin in the developing xylem of samples from mid-June was located exclusively in the middle lamella. The lignin was more condensed, was composed of guaiacyl units only and contained more end-groups than the reference Norway spruce wood.Thirdly, the cambial tissues of a Balsam poplar clone were surveyed during a growth season. Both the phloem side and the xylem side of the cambial region were examined. The Klason lignin content and carbohydrate monomer distribution showed that in June and August the tissues on the phloem side contained material with mainly middle lamella/primary walls. In June, the xylem side in the cambial region contained mainly middle lamella/primary walls, and in August the secondary cell wall carbohydrates were being deposited. Both tissues contained lignin that was more condensed and had more end-groups than the reference lignin. In mid-June, the developing xylem had a ratio of syringyl to guaiacyl units of 0.6, whereas the ratio for the reference wood was 1.3.In the final study, lignin from the primary cell walls from a hybrid aspen cell suspension culture was investigated. The lignin contained only guaiacyl units which were more condensed than those observed in the reference poplar wood.
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| 15. |
- Christiernin, Maria, et al.
(författare)
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Lignin isolated from primary walls of hybrid aspen cell cultures indicates significant differences in lignin structure between primary and secondary cell wall
- 2005
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Ingår i: Plant physiology and biochemistry (Paris). - : Elsevier BV. - 0981-9428 .- 1873-2690. ; 43:8, s. 777-785
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Tidskriftsartikel (refereegranskat)abstract
- Hybrid aspen (Populus tremula x tremuloides) cell cultures were grown for 7, 14 and 21 days. The cell cultures formed primary cell walls but no secondary cell wall according to carbohydrate analysis and microscopic characterization. The primary walls were lignified, increasingly with age, according to Klason lignin analysis. Presence of lignin in the primary walls, with a higher content in 21-day old cells than in 7-day old cells, was further Supported by phloroglucinol/HCI reagent test and confocal microscopy after both immunolocalization and staining with acriflavin. Both laccase and peroxidase activity were found in the cultures and the activity increased during lignin formation. The lignin from the cell culture material was compared to lignin from mature aspen wood, where most of the lignin originates in the secondary cell wall, and which served as our secondary cell wall control. Lignin from the cell walls was isolated and characterized by thioacidolysis followed by gas chromatography and mass spectrometry. The lignin in the cell cultures differed from lignin of mature aspen wood in that it consisted exclusively of guaiacyl units, and had a more condensed structure. Five lignin structures were identified by mass spectrometry in the cell suspension cultures. The results indicate that the hybrid aspen cell culture used in this investigation may be a convenient experimental system for studies of primary cell wall lignin.
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| 16. |
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| 17. |
- Giacomelli, Luca, et al.
(författare)
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Advanced Neutron Diagnostics for JET and ITER Fusion Experiments
- 2005
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 0029-5515 .- 1741-4326. ; 45, s. 1191-1201
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Tidskriftsartikel (refereegranskat)abstract
- The diagnostics functions of neutron measurements as well as the roles played by neutron yield monitors, cameras and spectrometers are reviewed. The importance of recent developments in neutron emission spectroscopy (NES) diagnostics is emphasized. Results are presented from the NES diagnosis of the Joint European Torus (JET) plasmas performed with the magnetic proton recoil (MPR) spectrometer during the first deuterium tritium experiment of 1997 and the recent trace tritium experiment of 2003. The NES diagnostic capabilities at JET are presently being enhanced by an upgrade of the MPR (MPRu) and a new 2.5 MeV time-of-flight (TOF) neutron spectrometer (TOFOR). The principles of MPRu and TOFOR are described and illustrated with the diagnostic role they will play in the high performance fusion experiments in the forward programme of JET largely aimed at supporting the International Thermonuclear Experimental Reactor (ITER). The importance of the JET NES effort for ITER is discussed.
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| 18. |
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| 19. |
- Henriksson, Gunnar, et al.
(författare)
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Lignin-carbohydrate network in wood and pulps : A determinant for reactivity
- 2007
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Ingår i: Holzforschung. - 0018-3830 .- 1437-434X. ; 61:6, s. 668-674
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Tidskriftsartikel (refereegranskat)abstract
- Pretreatment of wood or kraft pulp with endoglucanase followed by swelling in urea leaves a non-crystalline residue that can be dissolved in strong aqueous sodium hydroxide-sodium borate solution. A stepwise precipitation process employing acid and barium ions can separate lignin-carbohydrate complexes enriched in individual polysaccharides. This procedure has been applied to eucalypt and birch wood and to the corresponding kraft pulps. Thioacidolysis of the various lignin-carbohydrate complexes was used as the major analytical technique to obtain information about the structure and structural changes in lignin. A combination of thioacidolysis and size exclusion chromatography was used to obtain knowledge on the degree of depolymerisation and repolymerisation of lignin when going from wood to chemical pulp. In contrast to spruce wood and kraft pulp, complete recovery of the lignin-carbohydrate complexes could not be obtained from hardwood samples.
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| 20. |
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| 21. |
- Henriksson, Maria, 1979-
(författare)
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Production and engineering of a xyloglucan endo-transglycosylase from Populus tremula x tremuloides
- 2007
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this work was to develop a production process for the enzyme xyloglucan endo-transglycosylase from Populus tremula x tremuloides (PttXET16-34). The natural transglycosylating activity of this enzyme has previously been employed in a XET-Technology. This chemo enzymatic method is useful for biomimetic modification of cellulose surfaces and holds great potential for industrial applications. Thus, it requires that the XET-enzyme can be produced in larger scale.This work also shows how the wildtype PttXET16-34 was modified into a glycosynthase. By mutation of the catalytic nucleophile into an alanine, glycine or serine residue, enzymes capable of synthesising defined xyloglucan fragments were obtained. These defined compounds are very valuable for further detailed studies of xyloglucan active-enzymes, but are also useful in molecular studies of the structurally important xyloglucan-cellulose interaction.A heterologous production system for PttXET16-34 was previously developed in the methylotrophic yeast Pichia pastoris. A methanol-limited fed-batch process was also previously established, but the yield of active XET was low due to proteolysis problems and low productivity. Therefore, two alternative fed-batch techniques were investigated for the production of PttXET16-34: a temperature-limited fed-batch (TLFB) and an oxygen-limited high-pressure fed-batch (OLHPFB).For the initial recovery of XET after the fermentation process, two different downstream processes were investigated: expanded bed adsorption (EBA) and cross-flow filtration (CFF).
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| 22. |
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| 23. |
- Isaksson-Mettävainio, Martin, et al.
(författare)
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c-Met expression in primary tumors and their corresponding distant metastases
- 2009
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Ingår i: Molecular Medicine Reports. - Umeå : Spandidos Publications. - 1791-2997. ; 1:6, s. 787-790
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Tidskriftsartikel (refereegranskat)abstract
- c-Met is a receptor tyrosine kinase that has beenimplicated in the pathogenesis and growth of a wide variety ofhuman malignancies, including CRC, but its role in metastasisis largely unknown. We compared c-Met expression in primaryhuman colorectal carcinomas and distant metastases from thesame patients. Formalin-fixed paraffin-embedded tissuesamples from 69 colorectal cancer patients were obtained. Theprotein expression of c-Met was evaluated immunohistochemicallyusing a commercial antibody. The difference inexpression between primary tumors and their correspondingdistant metastases was analyzed using the Wilcoxon signedranktest. c-Met expression was statistically significantlylower in the distant metastases compared to their correspondingprimary tumors (p<0.001), whereas no difference was foundbetween lymph node metastases and their correspondingprimary tumors (p=0.957). The degree of c-Met expressionwas not related to clinicopathological characteristics such astumor grade and Dukes' stage at the time of primary tumordiagnosis, or to the location of the distant metastases. Wedemonstrated that c-Met expression is often reduced in distantmetastases compared to their corresponding primary colorectaltumors. Additional studies of c-Met activation and signaltransduction will increase our knowledge about the role ofc-Met in colorectal cancer metastasis.
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| 24. |
- Karlsson, Camilla, 1977, et al.
(författare)
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Identification of a stem cell niche in the zone of Ranvier within the knee joint.
- 2009
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Ingår i: Journal of anatomy. - : Wiley. - 0021-8782 .- 1469-7580. ; 215:3, s. 355-363
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Tidskriftsartikel (refereegranskat)abstract
- A superficial lesion of the articular cartilage does not spontaneously self-repair and has been suggested to be partly due to lack of progenitor cells within the joint that can reach the site of injury. To study whether progenitor cells are present within the joint, 3-month-old New Zealand white rabbits were exposed to bromodeoxyuridine (BrdU) for 12 consecutive days and were then sacrificed 4, 6, 10, 14, 28 and 56 days after the first BrdU administration. Presence of BrdU and localization of progenitor markers were detected using immunohistochemistry. After 10 days of BrdU exposure, BrdU-positive cells, i.e. proliferating cells, were abundantly detected in the epiphyseal plate, the perichondrial groove of Ranvier, and in all zones of the articular cartilage. After a wash-out period, BrdU-positive cells were still present, i.e. those considered to be progenitor cells, in these regions of the knee except for the proliferative zone of the epiphyseal plate. Cells in the perichondrial groove of Ranvier were further positive for several markers associated with progenitor cells and stem cell niches, including Stro-1, Jagged1, and BMPr1a. Our results demonstrate that a small population of progenitor cells is present in the perichondrial groove of Ranvier as well as within the articular cartilage in the knee. The perichondrial groove of Ranvier also demonstrates the properties of a stem cell niche.
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| 25. |
- Lonn, Stefan, et al.
(författare)
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Mobile phone use and risk of parotid gland tumor
- 2006
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Ingår i: American Journal of Epidemiology. - : Oxford University Press (OUP). - 0002-9262 .- 1476-6256. ; 164:7, s. 637-643
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Tidskriftsartikel (refereegranskat)abstract
- Handheld mobile phones were introduced in Denmark and Sweden during the late 1980s. This makes the Danish and Swedish populations suitable for a study aimed at testing the hypothesis that long-term mobile phone use increases the risk of parotid gland tumors. In this population-based case-control study, the authors identified all cases aged 20-69 years diagnosed with parotid gland tumor during 2000-2002 in Denmark and certain parts of Sweden. Controls were randomly selected from the study population base. Detailed information about mobile phone use was collected from 60 cases of malignant parotid gland tumors (85% response rate), 112 benign pleomorphic adenomas (88% response rate), and 681 controls (70% response rate). For regular mobile phone use, regardless of duration, the risk estimates for malignant and benign tumors were 0.7 (95% confidence interval: 0.4, 1.3) and 0.9 (95% confidence interval: 0.5, 1.5), respectively. Similar results were found for more than 10 years' duration of mobile phone use. The risk estimate did not increase, regardless of type of phone and amount of use. The authors conclude that the data do not support the hypothesis that mobile phone use is related to an increased risk of parotid gland tumors.
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| 28. |
- Nilsson, Jonas, 1974-
(författare)
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The LRIG-family: identification of novel regulators of ErbB signaling with clinical implications in astrocytoma
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Astrocytic tumors are the most common malignancies of the central nervous system, accounting for more than 60% of all primary brain tumors. The prognosis for high grade astrocytoma patients is dismal and there is no curative treatment, today. A molecular hallmark of astrocytic tumors is dysregulated receptor tyrosine kinase signaling, especially of the epidermal growth factor receptor (EGFR, ErbB1). The aim of the present thesis was to identify endogenous human proteins that downregulate the function of the ErbB1 receptor. We identified a human gene family, the leucine-rich repeats and immunoglobulin-like domains family (LRIG), consisting of LRIG1, LRIG2 and LRIG3, which might fulfill this criterion. Two candidates were identified, LRIG1 and LRIG2, which genes were localized to regions frequently deleted in human cancers, chromosome bands 3p14 and 1p13, respectively. LRIG1 and LRIG2 mRNA were expressed in all tissues analyzed, with high expression in brain and other organs. The LRIG mRNA were predicted to encode integral membrane proteins. Antibodies against LRIG1 and LRIG2 were developed and the protein expression was analyzed. LRIG1 was found to have an apparent molecular weight of 143 kDa and was expressed in most tissues with high expression in glandular tissues of the breast and prostate, and the peptic cells of the stomach. LRIG2 was slightly smaller and had an apparent molecular weight of 132 kDa. The LRIG proteins were localized to the cell surface and to perinuclear structures, where LRIG1 co-localized with the trans-Golgi network and early endosomes. LRIG1 was found to restrict growth factor signaling by enhancing receptor ubiquitylation and degradation. We showed that LRIG1 interacted with all four members of the ErbB family and induced their downregulation. The interaction with ErbB1 involved both the LRR-domains and the Ig-like domains of LRIG1. LRIG1 enhanced receptor degradation by recruiting the E3 ubiquitin ligase c-Cbl to the LRIG1-ErbB1 complex. LRIG1, LRIG2, and LRIG3 were expressed in glioma cell lines and tumor tissues. The LRIG expression was analyzed in 404 astrocytic tumor samples. We found that perinuclear LRIG protein expression correlated with increased survival of patients with astrocytic tumors. Especially perinuclear LRIG3 showed strong correlations with patient survival and tumor cell proliferation index. In summary, this thesis contains the discovery and characterization of human LRIG1 and LRIG2. LRIG1 was found to interact with ErbB receptors and downregulate their function. In a clinical material, expression of LRIG proteins correlated with survival in patients with astrocytic tumors.
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| 29. |
- Piens, Kathleen, et al.
(författare)
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Glycosynthase activity of hybrid aspen xyloglucan endo-transglycosylase PttXET16-34 nucleophile mutants
- 2007
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Ingår i: Organic and Biomolecular Chemistry. - : Royal Society of Chemistry (RSC). - 1477-0520 .- 1477-0539. ; 5:24
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Tidskriftsartikel (refereegranskat)abstract
- Glycosynthases are active-site mutants of glycoside hydrolases that catalyse glycosyl transfer using suitable activated donor substrates without competing product hydrolysis ( S. M. Hancock, M. D. Vaughan and S. G. Withers, Curr. Opin. Chem. Biol., 2006, 10, 509-519). Site-directed mutagenesis of the catalytic nucleophile, Glu-85, of a Populus tremula x tremuloides xyloglucan endo-transglycosylase (PttXET16-34, EC 2.4.1.207) into alanine, glycine, and serine yielded enzymes with glycosynthase activity. Product analysis indicated that PttXET16-34 E85A in particular was able to catalyse regio- and stereospecific homo- and hetero- condensations of alpha-xylogluco-oligosaccharyl fluoride donors XXXG alpha F andXLLG alpha F to produce xyloglucans with regular sidechain substitution patterns. This substrate promiscuity contrasts that of the Humicola insolens Ce17B E197A glycosynthase, which was not able to polymerise the di-galactosylated substrate XLLG alpha F. The production of the PttXET16-34 E85A xyloglucosynthase thus expands the repertoire of glycosynthases to include those capable of synthesising structurally homogenenous xyloglucans
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| 30. |
- Sandström, Maria, et al.
(författare)
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Effects of the VEGFR inhibitor ZD6474 in combination with radiotherapy and temozolomide in an orthotopic glioma model.
- 2008
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Ingår i: Journal of Neuro-Oncology. - : Springer Science and Business Media LLC. - 0167-594X .- 1573-7373. ; 88:1, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- AIM OF THE STUDY:The extensive neovascularisation of malignant glioma is mainly influenced by vascular endothelial growth factor (VEGF). The effect of ZD6474, a potent inhibitor of VEGF-receptor-2, was evaluated in combination with either radiotherapy or temozolomide.METHODS:The effects on glioma growth were investigated in the intracerebral BT4C rat glioma model. ZD6474 30 mg/kg was given alone or in combination with radiotherapy 12 Gy x 1 or with temozolomide 100 mg/kg for 3 days. Two different experiments were performed comparing ZD6474 to radiotherapy or temozolomide. For each experiment 28 animals were randomized into four groups.RESULTS:ZD6474 in combination with radiotherapy significantly decreased tumour area by 66% compared with controls whereas the combination with temozolomide decreased tumour area by 74%.CONCLUSIONS:ZD6474 in combination with two standard modalities in the treatment of malignant glioma, radiotherapy and chemotherapy, markedly decreased the growth of an intracerebral experimental glioma. These results justify further investigations of these therapies in combination.
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| 31. |
- Sandström, Maria, 1969-
(författare)
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Experimental therapies of malignant glioma : with emphasis on angiogenesis inhibition
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Malignant glioma consists of a group of diseases where the localisation and the nature of the disease makes treatment an extreme challenge. Two important biological features of malignant glioma cells are their infiltrative growth and their ability to induce angiogenesis. Glioma cells migrate extensively behind the blood-brain barrier and infiltrate the surrounding brain making radical treatment with surgery and radiotherapy almost impossible. The aims of this thesis were to investigate factors of importance for glioma cell migration and angiogenesis and to evaluate if an anti-angiogenesis approach alone or in combination with current treatment modalities could inhibit glioma growth. For this purpose we used the BT4C orthotopic rat glioma model and investigated treatment effects of the vascular endothelial growth factor (VEGF) receptor-2 and epidermal growth factor (EGF) receptor tyrosine kinase inhibitor ZD6474 alone or in combination with temozolomide or radiotherapy. Altered protein expression pattern after anti-angiogenesis treatment was measured using a mass-spectrometric proteomic method, followed by multivariate data-analysis. The tissue plasminogen activator (tPA), urokinase plasminogen activator (uPA), plasminogen activator inhibitor-1 (PAI-1), and VEGF showed altered temporal and spatial mRNA expression during glioma progression. In early stages of tumour progression the expression was found throughout the tumour while in later stages, the expression was more predominant in the invasive tumour border. ZD6474 in monotherapy significantly inhibited tumour growth in the BT4C glioma model. The effect was further enhanced when combined with radiotherapy or temozolomide. Using mass-spectrometric methods an altered protein expression pattern after ZD6474 treatment was observed implicating the possibility to use proteomic methods for finding predictive biomarkers for anti-angiogenesis treatment. In conclusion, this thesis demonstrates a co-expression of factors important for glioma growth and angiogenesis and that treatment with an angiogenesis inhibitor has additive effects on glioma growth when combined with radiotherapy and chemotherapy. Finally, an altered protein expression pattern after anti-angiogenesis treatment is evident and detectable. Hopefully this work will contribute to and encourage further research to reach a better understanding of how to combine and evaluate different treatment approaches in malignant glioma.
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| 32. |
- Shete, Sanjay, et al.
(författare)
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Genome-wide association study identifies five susceptibility loci for glioma.
- 2009
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 41:8, s. 899-904
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Tidskriftsartikel (refereegranskat)abstract
- To identify risk variants for glioma, we conducted a meta-analysis of two genome-wide association studies by genotyping 550K tagging SNPs in a total of 1,878 cases and 3,670 controls, with validation in three additional independent series totaling 2,545 cases and 2,953 controls. We identified five risk loci for glioma at 5p15.33 (rs2736100, TERT; P = 1.50 x 10(-17)), 8q24.21 (rs4295627, CCDC26; P = 2.34 x 10(-18)), 9p21.3 (rs4977756, CDKN2A-CDKN2B; P = 7.24 x 10(-15)), 20q13.33 (rs6010620, RTEL1; P = 2.52 x 10(-12)) and 11q23.3 (rs498872, PHLDB1; P = 1.07 x 10(-8)). These data show that common low-penetrance susceptibility alleles contribute to the risk of developing glioma and provide insight into disease causation of this primary brain tumor.
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