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Sooman, Linda
Publications (10 of 10) Show all publications
Sooman, L., Freyhult, E., Jaiswal, A., Navani, S., Edqvist, P.-H., Pontén, F., . . . Ekman, S. (2015). FGF2 as a potential prognostic biomarker for proneural glioma patients. Acta Oncologica, 54(3), 385-394
Open this publication in new window or tab >>FGF2 as a potential prognostic biomarker for proneural glioma patients
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2015 (English)In: Acta Oncologica, ISSN 0284-186X, E-ISSN 1651-226X, Vol. 54, no 3, p. 385-394Article in journal (Refereed) Published
Abstract [en]

Background. The survival of high-grade glioma patients is poor and the treatment of these patients can cause severe side effects. This fosters the necessity to identify prognostic biomarkers, in order to optimize treatment and diminish unnecessary suffering of patients. The aim of this study was to identify prognostic biomarkers for high-grade glioma patients.

Methods. Eleven proteins were selected for analysis due to their suggested importance for survival of patients with other types of cancers and due to a high variation in protein levels between glioma patients (according to the Human Protein Atlas, www.proteinatlas.org). Protein expression patterns of these 11 proteins were analyzed by immunohistochemistry in tumor samples from 97 high-grade glioma patients. The prognostic values of the proteins were analyzed with univariate and multivariate Cox regression analyses for the high-grade glioma patients, including subgroup analyses of histological subtypes and immunohistochemically defined molecular subtypes.

Results. The proteins with the most significant (univariate and multivariate p < 0.05) correlations were analyzed further with cross-validated Kaplan-Meier analyses for the possibility of predicting survival based on the protein expression pattern of the corresponding candidate. Random Forest classification with variable subset selection was used to analyze if a protein signature consisting of any combination of the 11 proteins could predict survival for the high-grade glioma patients and the subgroup with glioblastoma patients. The proteins which correlated most significantly (univariate and multivariate p < 0.05) to survival in the Cox regression analyses were Myc for all high-grade gliomas and FGF2, CA9 and CD44 for the subgroup of proneural gliomas, with FGF2 having a strong negative predictive value for survival. No prognostic signature of the proteins could be found.

Conclusion. FGF2 is a potential prognostic biomarker for proneural glioma patients, and warrants further investigation.

Keywords
Prognostic biomarkers, tissue microarray, immunohistochemistry, FGF2, CA9, CD44
National Category
Cell and Molecular Biology Cancer and Oncology
Identifiers
urn:nbn:se:uu:diva-214802 (URN)10.3109/0284186X.2014.951492 (DOI)000350646400012 ()25263081 (PubMedID)
Available from: 2014-01-09 Created: 2014-01-09 Last updated: 2018-01-11Bibliographically approved
Sooman, L. (2014). Prognostic Biomarkers and Target Proteins for Treatment of High-grade Gliomas. (Doctoral dissertation). Uppsala: Acta Universitatis Upsaliensis
Open this publication in new window or tab >>Prognostic Biomarkers and Target Proteins for Treatment of High-grade Gliomas
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The survival for high-grade glioma patients is poor and the treatment may cause severe side effects. A common obstacle in the treatment is chemoresistance. To improve the quality of life and prolong survival for these patients prognostic biomarkers and new approaches for chemotherapy are needed. To this end, a strategy to evade chemoresistance was evaluated by combining chemotherapeutic drugs with agents inhibiting resistance mechanisms identified by a bioinformatic analysis (paper I). The prognostic value of 13 different proteins was analyzed in this thesis (papers II-IV). Two of them, p38 mitogen-activated protein kinase (MAPK) and protein tyrosine phosphatase non-receptor type 6 (PTPN6, also known as SHP1) were analyzed for their potential as targets in combination chemotherapy (in paper III and IV, respectively).

 

We found that:

  1. PTPN6 expression and methylation status may be important for survival of anaplastic glioma patients, p38 MAPK phosphorylation may be a potential negative prognostic biomarker for high-grade glioma patients and FGF2 expression may be a potential negative prognostic biomarker for proneural glioma patients.
  2. PTPN6 may be a useful target for combination chemotherapy with cisplatin, melphalan or bortezomib in high-grade gliomas. The following drug combinations; camptothecin combined with an EGFR or RAC1 inhibitor, imatinib combined with a Notch or RAC1 inhibitor, temozolomide combined with an EGFR or FAK inhibitor and vandetanib combined with a p38 MAPK inhibitor may be useful combination chemotherapy for high-grade gliomas.
Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2014. p. 74
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine, ISSN 1651-6206 ; 965
Keywords
High-grade glioma, prognostic biomarkers, combination chemotherapy, DNA methylation, FGF2, p38 MAPK, PTPN6, camptothecin, imatinib, vandetanib, EGFR, RAC1, Notch
National Category
Cell and Molecular Biology Cancer and Oncology
Research subject
Medical Science; Oncology
Identifiers
urn:nbn:se:uu:diva-215079 (URN)978-91-554-8839-0 (ISBN)
Public defence
2014-03-07, Rudbecksalen, Rudbecklaboratoriet, Dag Hammarskjölds väg 20, Uppsala, 13:15 (English)
Opponent
Supervisors
Available from: 2014-02-13 Created: 2014-01-10 Last updated: 2018-01-11
Sooman, L., Ekman, S., Tsakonas, G., Jaiswal, A., Navani, S., Edqvist, P.-H., . . . Lennartsson, J. (2014). PTPN6 expression is epigenetically regulated and influences survival and response to chemotherapy in high-grade gliomas. Tumor Biology, 35(5), 4479-4488
Open this publication in new window or tab >>PTPN6 expression is epigenetically regulated and influences survival and response to chemotherapy in high-grade gliomas
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2014 (English)In: Tumor Biology, ISSN 1010-4283, E-ISSN 1423-0380, Vol. 35, no 5, p. 4479-4488Article in journal (Refereed) Published
Abstract [en]

Background: The prognosis of high-grade glioma patients is poor and the tumors are characterized by resistance to therapy. The aims of this study were to analyze the prognostic value of the expression of the protein tyrosine phosphatase, non-receptor type 6 (PTPN6, also referred to as SHP1) in high-grade glioma patients and the epigenetic regulation of the expression of PTPN6 and the role of its expression in chemotherapy resistance in glioma-derived cells.

Material and methods: PTPN6 expression was analyzed with immunohistochemistry in 89 high-grade glioma patients. Correlation between PTPN6 expression and overall survival was analyzed with Kaplan-Meier univariate analysis and Cox regression multivariate analysis. Differences in drug sensitivity to a panel of 16 chemotherapeutic drugs between PTPN6 overexpressing clones and control clones were analyzed in vitro with the fluorometric microculture cytotoxicity assay. Cell cycle analysis was done with Krishan staining and flow cytometry. Apoptosis was analyzed with a cell death detection ELISA kit as well as cleaved caspase-3 and caspase-9 Western blotting. Autophagy was analyzed with LC3B Western blotting. Methylation of the PTPN6 promoter was analyzed with bisulfite-Pyrosequencing and demethylation of PTPN6 was done with decitabine treatment.

Results: PTPN6 expression correlated in univariate analysis to poor survival for anaplastic glioma patients (p=0.026). In glioma-derived cell lines, overexpression of PTPN6 caused increased resistance (p<0.05) to the chemotherapeutic drugs bortezomib, cisplatin and melphalan. PTPN6 expression did not affect bortezomib-induced cell cycle arrest, apoptosis or autophagy. Low PTPN6 promoter methylation correlated to protein expression and the protein expression was increased upon demethylation in glioma-derived cells.

Conclusion: PTPN6 expression may be a factor contributing to poor survival for anaplastic glioma patients and in glioma-derived cells its expression is epigenetically regulated and influences the response to chemotherapy.

Keywords
high-grade glioma, PTPN6, SHP1, survival, chemotherapy, methylation
National Category
Cell and Molecular Biology
Identifiers
urn:nbn:se:uu:diva-214761 (URN)10.1007/s13277-013-1590-5 (DOI)000335759800063 ()
Available from: 2014-01-09 Created: 2014-01-09 Last updated: 2018-01-11Bibliographically approved
Popova, S. N., Bergqvist, M., Dimberg, A., Edqvist, P.-H., Ekman, S., Hesselager, G., . . . Alafuzoff, I. (2014). Subtyping of gliomas of various WHO grades by the application of immunohistochemistry. Histopathology, 64(3), 365-379
Open this publication in new window or tab >>Subtyping of gliomas of various WHO grades by the application of immunohistochemistry
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2014 (English)In: Histopathology, ISSN 0309-0167, E-ISSN 1365-2559, Vol. 64, no 3, p. 365-379Article in journal (Refereed) Published
Abstract [en]

Aims

In 2010, four subtypes (classical, proneural, mesenchymal, and neural) of glioblastoma multiforme (GBM) were defined by molecular genetic analyses. The objective of this study was to assess whether gliomas, independently of the type and grade, could be subdivided into protein-based subtypes.

Methods and results

A tissue microarray (TMA) approach was applied to incorporate tissue samples of low-grade and high-grade gliomas into five TMAs. High expression levels of epidermal growth factor receptor (EGFR), CD44, c-MER proto-oncogene tyrosine kinase (MERTK), platelet-derived growth factor receptor α, p53, oligodendrocyte transcription factor 2 (OLIG2) and isocitrate dehydrogenase 1 with the R132H mutation were assessed using immunohistochemistry (IHC). Glioma could be subdivided into four subtypes by IHC. The majority of the low-grade gliomas were of the proneural subtype, i.e. high p53 expression (63% of grade II). The classical subtype, with high EGFR and low p53 expression, was most common in GBMs (39%), followed by the proneural (29%) and mesenchymal (with high CD44 and MERTK expression) (29%) subtypes, a frequency that is in line with previously published data based on molecular genetics.

Conclusions

Assessment of the expression of the five proteins EGFR, CD44, MERTK, p53 and OLIG2 is sufficient for subtyping gliomas, and can be recommended for implementation in clinical practice for both low-grade and high-grade gliomas.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-215836 (URN)10.1111/his.12252 (DOI)000330638700005 ()
Available from: 2014-01-17 Created: 2014-01-17 Last updated: 2017-12-06Bibliographically approved
Wu, X., Sooman, L., Wickström, M., Fryknäs, M., Dyrager, C., Lennartsson, J. & Gullbo, J. (2013). Alternative Cytotoxic Effects of the Postulated IGF-IR Inhibitor Picropodophyllin In Vitro. Molecular Cancer Therapeutics, 12(8), 1526-1536
Open this publication in new window or tab >>Alternative Cytotoxic Effects of the Postulated IGF-IR Inhibitor Picropodophyllin In Vitro
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2013 (English)In: Molecular Cancer Therapeutics, ISSN 1535-7163, E-ISSN 1538-8514, Vol. 12, no 8, p. 1526-1536Article in journal (Refereed) Published
Abstract [en]

The insulin-like growth factor-1 (IGF-I) and its receptors play an important role in transformation and progression of several malignancies. Inhibitors of this pathway have been developed and evaluated but generally performed poorly in clinical trials, and several drug candidates have been abandoned. The cyclolignan picropodophyllin (PPP) has been described as a potent and selective IGF-IR inhibitor and is currently undergoing clinical trials. We investigated PPP's activity in panels of human cancer cell lines (e.g., esophageal squamous carcinoma cell lines) but found no effects on the phosphorylation or expression of IGF-IR. Nor was the cytotoxic activity of PPP related to the presence or spontaneous phosphorylation of IGF-IR. However, its activity correlated with that of known tubulin inhibitors, and it destabilized microtubule assembly at cytotoxic concentrations also achievable in patients. PPP is a stereoisomer of podophyllotoxin (PPT), a potent tubulin inhibitor, and an equilibrium between the two has previously been described. PPP could thus potentially act as a reservoir for the continuous generation of low doses of PPT. Interestingly, PPP also inhibited downstream signaling from tyrosine kinase receptors, including the serine/threonine kinase Akt. This effect is associated with microtubule-related downregulation of the EGF receptor, rather than the IGF-IR. These results suggest that the cytotoxicity and pAkt inhibition observed following treatment with the cyclolignan PPP in vitro result from microtubule inhibition (directly or indirectly by spontaneous PPT formation), rather than any effect on IGF-IR. It is also suggested that PPT should be used as a reference compound in all future studies on PPP.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-206802 (URN)10.1158/1535-7163.MCT-13-0091 (DOI)000322908400014 ()23699657 (PubMedID)
Note

De två (2) sista författarna delar sistaförfattarskapet.

Available from: 2013-09-04 Created: 2013-09-04 Last updated: 2017-12-06Bibliographically approved
Wu, X., Sooman, L., Lennartsson, J., Bergström, S., Bergqvist, M., Gullbo, J. & Ekman, S. (2013). Microtubule inhibition causes epidermal growth factor receptor inactivation in oesophageal cancer cells. International Journal of Oncology, 42(1), 297-304
Open this publication in new window or tab >>Microtubule inhibition causes epidermal growth factor receptor inactivation in oesophageal cancer cells
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2013 (English)In: International Journal of Oncology, ISSN 1019-6439, Vol. 42, no 1, p. 297-304Article in journal (Refereed) Published
Abstract [en]

Drugs that interfere with microtubule function can prevent cells from mitosis and may cause cell cycle arrest or apoptosis. Various microtubule targeting agents, both stabilizers and inhibitors, are used in a clinical setting to treat cancer. In the current study, we investigated the sensitivity of oesophageal cancer cells to different microtubule targeting agents. The current study demonstrated that different microtubule targeting agents disrupted the microtubule network and inhibited survival of oesophageal cancer cells in a dose-dependent manner. Interestingly, an additional cellular effect with inhibition of tyrosine phosphorylation of the EGFR and subsequent downregulation of EGFR-induced signalling was also observed, suggesting an additional mechanism of action for microtubule destabilising agents. A tyrosine phosphatase inhibitor, sodium orthovanadate, could reverse the EGFR dephosphorylation effects induced by microtubule targeting agents. The EGFR dephosphorylation could be reversed by a tyrosine phosphatase inhibitor, indicating that disruption of the microtubule network may lead to activation of a protein tyrosine phosphatasc (PTP) that can regulate EGFR phosphorylation and activation, an effect of potential clinical relevance for combination therapies in patients.

Keywords
microtubule targeting agents, epidermal growth factor, tyrosine phosphatase, oesophageal cancer cells
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-192442 (URN)10.3892/ijo.2012.1710 (DOI)000312566900034 ()
Available from: 2013-01-24 Created: 2013-01-21 Last updated: 2017-12-06Bibliographically approved
Sooman, L., Ekman, S., Andersson, C., Kultima, H. G., Isaksson, A., Johansson, F., . . . Gullbo, J. (2013). Synergistic interactions between camptothecin and EGFR or RAC1 inhibitors and between imatinib and Notch signaling or RAC1 inhibitors in glioblastoma cell lines. Cancer Chemotherapy and Pharmacology, 72(2), 329-340
Open this publication in new window or tab >>Synergistic interactions between camptothecin and EGFR or RAC1 inhibitors and between imatinib and Notch signaling or RAC1 inhibitors in glioblastoma cell lines
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2013 (English)In: Cancer Chemotherapy and Pharmacology, ISSN 0344-5704, E-ISSN 1432-0843, Vol. 72, no 2, p. 329-340Article in journal (Refereed) Published
Abstract [en]

The current treatment strategies for glioblastoma have limited health and survival benefits for the patients. A common obstacle in the treatment is chemoresistance. A possible strategy to evade this problem may be to combine chemotherapeutic drugs with agents inhibiting resistance mechanisms. The aim with this study was to identify molecular pathways influencing drug resistance in glioblastoma-derived cells and to evaluate the potential of pharmacological interference with these pathways to identify synergistic drug combinations. Global gene expressions and drug sensitivities to three chemotherapeutic drugs (imatinib, camptothecin and temozolomide) were measured in six human glioblastoma-derived cell lines. Gene expressions that correlated to drug sensitivity or resistance were identified and mapped to specific pathways. Selective inhibitors of these pathways were identified. The effects of six combinations of inhibitors and chemotherapeutic drugs were evaluated in glioblastoma-derived cell lines. Drug combinations with synergistic effects were also evaluated in non-cancerous epithelial cells. Four drug combinations had synergistic effects in at least one of the tested glioblastoma-derived cell lines; camptothecin combined with gefitinib (epidermal growth factor receptor inhibitor) or NSC 23766 (ras-related C3 botulinum toxin substrate 1 inhibitor) and imatinib combined with DAPT (Notch signaling inhibitor) or NSC 23766. Of these, imatinib combined with DAPT or NSC 23766 did not have synergistic effects in non-cancerous epithelial cells. Two drug combinations had at least additive effects in one of the tested glioblastoma-derived cell lines; temozolomide combined with gefitinib or PF-573228 (focal adhesion kinase inhibitor). Four synergistic and two at least additive drug combinations were identified in glioblastoma-derived cells. Pathways targeted by these drug combinations may serve as targets for future drug development with the potential to increase efficacy of currently used/evaluated chemotherapy.

Keywords
Glioblastoma, Synergistic drug combinations, Camptothecin, Imatinib
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-207017 (URN)10.1007/s00280-013-2197-7 (DOI)000322132600006 ()
Available from: 2013-09-10 Created: 2013-09-09 Last updated: 2017-12-06Bibliographically approved
Sooman, L., Lennartsson, J., Gullbo, J., Bergqvist, M., Tsakonas, G., Johansson, F., . . . Ekman, S. (2013). Vandetanib combined with a p38 MAPK inhibitor synergistically reduces glioblastoma cell survival. Medical Oncology, 30(3), 638
Open this publication in new window or tab >>Vandetanib combined with a p38 MAPK inhibitor synergistically reduces glioblastoma cell survival
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2013 (English)In: Medical Oncology, ISSN 1357-0560, E-ISSN 1559-131X, Vol. 30, no 3, p. 638-Article in journal (Refereed) Published
Abstract [en]

The survival for patients with high-grade glioma is poor, and only a limited number of patients respond to the therapy. The aim of this study was to analyze the significance of using p38 MAPK phosphorylation as a prognostic marker in high-grade glioma patients and as a therapeutic target in combination chemotherapy with vandetanib. p38 MAPK phosphorylation was analyzed with immunohistochemistry in 90 high-grade glioma patients. Correlation between p38 MAPK phosphorylation and overall survival was analyzed with Mann-Whitney U test analysis. The effects on survival of glioblastoma cells of combining vandetanib with the p38 MAPK inhibitor SB 203580 were analyzed in vitro with the median-effect method with the fluorometric microculture cytotoxicity assay. Two patients had phosphorylated p38 MAPK in both the cytoplasm and nucleus, and these two presented with worse survival than patients with no detectable p38 MAPK phosphorylation or phosphorylated p38 MAPK only in the nucleus. This was true for both high-grade glioma patients (WHO grade III and IV, n = 90, difference in median survival: 6.1 months, 95 % CI [0.20, 23], p = 0.039) and for the subgroup with glioblastoma patients (WHO grade IV, n = 70, difference in median survival: 6.1 months, 95 % CI [0.066, 23], p = 0.043). The combination of vandetanib and the p38 MAPK inhibitor SB 203580 had synergistic effects on cell survival for glioblastoma-derived cells in vitro. In conclusion, p38 MAPK phosphorylation may be a prognostic marker for high-grade glioma patients, and vandetanib combined with a p38 MAPK inhibitor may be useful combination chemotherapy for glioma patients.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-202678 (URN)10.1007/s12032-013-0638-0 (DOI)000323662900047 ()23783486 (PubMedID)
Available from: 2013-06-25 Created: 2013-06-25 Last updated: 2017-12-06Bibliographically approved
Sooman, L., Ekman, S., Bergqvist, M., Gullbo, J., Bergstrom, S., Johansson, M., . . . Lennartsson, J. (2012). SHP1 expression is epigenetically regulated and influences the sensitivity to chemotherapeutic agents in glioblastoma cells. Paper presented at 10th Congress of the European-Association-of-NeuroOncology, SEP 06-09, 2012, Marseille, FRANCE. Neuro-Oncology, 14(suppl 3), iii18-iii18
Open this publication in new window or tab >>SHP1 expression is epigenetically regulated and influences the sensitivity to chemotherapeutic agents in glioblastoma cells
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2012 (English)In: Neuro-Oncology, ISSN 1522-8517, E-ISSN 1523-5866, Vol. 14, no suppl 3, p. iii18-iii18Article in journal, Meeting abstract (Other academic) Published
Abstract [en]

INTRODUCTION: Glioblastoma is characterized by chemoresistance. One factor than can contribute to chemoresistance is aberrant DNA methylation of specific genes relevant for drug response, e.g. tumor suppressor genes. AIM: The aim of this study was to investigate whether the tumor suppressor gene SHP1 is epigenetically regulated and if its overexpression affects the sensitivity to chemotherapeutic drugs with different mechanisms of action in glioblastoma cell lines.

METHODS: Differences in methylation levels in the SHP1 promoter and SHP1 protein expressions between untreated cells and cells treated with the demethylating agent decitabine were analyzed with bisulfite Pyrosequencing and Western blotting. Differences in drug sensitivity to a panel of chemotherapeutic drugs with different mechanisms of action between SHP1 overexpressing clones and control clones were analyzed with the fluorometric microculture cytotoxicity assay.

RESULTS: We demonstrated that SHP1 promoter methylation was correlated to SHP1 expression and that the expression was increased upon demethylation. Overexpression of SHP1 resulted in lower (p < 0.05) sensitivity to the proteasome inhibitor bortezomib and the alkylating agents cisplatin and melphalan.

CONCLUSION: SHP1 expression may be epigenetically regulated and its overexpression influences the sensitivity to chemotherapeutic drugs in glioblastoma derived cells.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-182415 (URN)10.1093/neuonc/nos183 (DOI)000308545600067 ()
Conference
10th Congress of the European-Association-of-NeuroOncology, SEP 06-09, 2012, Marseille, FRANCE
Available from: 2012-10-11 Created: 2012-10-10 Last updated: 2017-12-07Bibliographically approved
Sooman, L., Ekman, S., Andersson, C., Johansson, F., Göransson-Kultima, H., Isaksson, A., . . . Gullbo, J. (2012). Synergistic Effects of PI3K or P38 MAPK Inhibition in Combination With Vandetanib Treatment in Glioblastoma Cells. Paper presented at 22nd Biennial Congress of the European-Association-for-Cancer-Research, JUL 07-10, 2012, Barcelona, SPAIN. European Journal of Cancer, 48(S5), S244-S244
Open this publication in new window or tab >>Synergistic Effects of PI3K or P38 MAPK Inhibition in Combination With Vandetanib Treatment in Glioblastoma Cells
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2012 (English)In: European Journal of Cancer, ISSN 0959-8049, E-ISSN 1879-0852, Vol. 48, no S5, p. S244-S244Article in journal, Meeting abstract (Refereed) Published
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-194487 (URN)10.1016/S0959-8049(12)71629-5 (DOI)000313036501473 ()
Conference
22nd Biennial Congress of the European-Association-for-Cancer-Research, JUL 07-10, 2012, Barcelona, SPAIN
Available from: 2013-02-14 Created: 2013-02-14 Last updated: 2017-12-06Bibliographically approved
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