| 1. |
- Burestedt, Elisabeth
(författare)
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Enzymatic and Immunological Detection Principles for Environmental and Biological Applications
- 1999
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of the thesis was to develop new analytical detection principles based on enzymatic and immunological reactions for sensitive, selective, cost-effective and high sample through-put detection devices. The thesis presents the basic elements and reaction paths necessary for the construction and development of enzyme based amperometric biosensors and immunoassays. The developed biochemical detection devices were utilised for the analysis of phenolic compounds, s-triazine herbicides, D-amino acids and interleukin-8. The thesis thus covers applications in both environmental and biological samples. D-amino acid biosensors were developed by co-immobilising D-amino acid oxidase and peroxidase into carbon paste electrodes. The detection principle is based on coupled reactions between the two enzymes. Various types of tyrosinase amperometric biosensors were developed for the analysis of mono- and di-phenolic compounds. An amplification of the overall signal is possible to achieve by the reduction of the enzymatically produced product at the electrode surface. Amplification factors and rate limiting steps of three different sensor configurations were investigated in order to further improve the sensitivity and stability of tyrosinase based amperometric biosensors. The developed tyrosinase biosensors were integrated on-line with sample handling and liquid chromatographic techniques for the analysis of phenolic compound in environmental as well as biological samples. An enzyme flow immunoassay technique for atrazine using b-galactosidase as the enzyme label and a cellobiose dehydrogenase (CDH) biosensor as the label detector was developed. The optimised system was applied to the analysis of atrazine in spiked surface water samples, by utilising both the CDH biosensor and colourimetric detection. A non-competitive flow immunoassay method was developed for the analysis of interleukin-8 in cell samples.
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| 2. |
- Gil, Jeovanis, et al.
(författare)
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Clinical protein science in translational medicine targeting malignant melanoma
- 2019
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Ingår i: Cell Biology and Toxicology. - : Springer Science and Business Media LLC. - 0742-2091 .- 1573-6822. ; 35:4, s. 293-332
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Tidskriftsartikel (refereegranskat)abstract
- Melanoma of the skin is the sixth most common type of cancer in Europe and accounts for 3.4% of all diagnosed cancers. More alarming is the degree of recurrence that occurs with approximately 20% of patients lethally relapsing following treatment. Malignant melanoma is a highly aggressive skin cancer and metastases rapidly extend to the regional lymph nodes (stage 3) and to distal organs (stage 4). Targeted oncotherapy is one of the standard treatment for progressive stage 4 melanoma, and BRAF inhibitors (e.g. vemurafenib, dabrafenib) combined with MEK inhibitor (e.g. trametinib) can effectively counter BRAFV600E-mutated melanomas. Compared to conventional chemotherapy, targeted BRAFV600E inhibition achieves a significantly higher response rate. After a period of cancer control, however, most responsive patients develop resistance to the therapy and lethal progression. The many underlying factors potentially causing resistance to BRAF inhibitors have been extensively studied. Nevertheless, the remaining unsolved clinical questions necessitate alternative research approaches to address the molecular mechanisms underlying metastatic and treatment-resistant melanoma. In broader terms, proteomics can address clinical questions far beyond the reach of genomics, by measuring, i.e. the relative abundance of protein products, post-translational modifications (PTMs), protein localisation, turnover, protein interactions and protein function. More specifically, proteomic analysis of body fluids and tissues in a given medical and clinical setting can aid in the identification of cancer biomarkers and novel therapeutic targets. Achieving this goal requires the development of a robust and reproducible clinical proteomic platform that encompasses automated biobanking of patient samples, tissue sectioning and histological examination, efficient protein extraction, enzymatic digestion, mass spectrometry–based quantitative protein analysis by label-free or labelling technologies and/or enrichment of peptides with specific PTMs. By combining data from, e.g. phosphoproteomics and acetylomics, the protein expression profiles of different melanoma stages can provide a solid framework for understanding the biology and progression of the disease. When complemented by proteogenomics, customised protein sequence databases generated from patient-specific genomic and transcriptomic data aid in interpreting clinical proteomic biomarker data to provide a deeper and more comprehensive molecular characterisation of cellular functions underlying disease progression. In parallel to a streamlined, patient-centric, clinical proteomic pipeline, mass spectrometry–based imaging can aid in interrogating the spatial distribution of drugs and drug metabolites within tissues at single-cell resolution. These developments are an important advancement in studying drug action and efficacy in vivo and will aid in the development of more effective and safer strategies for the treatment of melanoma. A collaborative effort of gargantuan proportions between academia and healthcare professionals has led to the initiation, establishment and development of a cutting-edge cancer research centre with a specialisation in melanoma and lung cancer. The primary research focus of the European Cancer Moonshot Lund Center is to understand the impact that drugs have on cancer at an individualised and personalised level. Simultaneously, the centre increases awareness of the relentless battle against cancer and attracts global interest in the exceptional research performed at the centre.
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| 4. |
- Marko-Varga, György, et al.
(författare)
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Effect of HY-Zeolites on the Performance of Tyrosinase-Modified Carbon Paste Electrodes
- 1996
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Ingår i: Electroanalysis. - Weinheim : Wiley-VCH Verlagsgesellschaft. - 1040-0397 .- 1521-4109. ; 8:12, s. 1121-1126
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Tidskriftsartikel (refereegranskat)abstract
- The dependence of electrode response on additive properties in enzyme-modified carbon paste was studied. Four different HY-zeolite powders, dealuminated to different extents and characterized by both Si/Al ratio and hydrophilicity, were used as the carbon paste modifiers. The enzyme tyrosinase used in biosensors for the detection of catechol and other phenolic compounds was chosen as the model system for the construction of a composite carbon paste biosensor incorporating different HY-zeolites as additives. Tyrosinase was trapped on the HY-zeolite particles from a buffer solution, dried and mixed with graphite powder and a pasting oil. It was found that by incorporating HY-zeolites into the carbon paste the heterogeneous reaction rate of catechol redox conversion and the signal response for catechol were increased. In the latter case a higher response was observed for increased hydrophilicity, i.e., decreased Si/Al ratio of the HY-zeolite. The carbon paste/solution interface is considered to be an aqueous/organic phase and the characteristics of the enzyme-modified carbon paste electrode are related to theories, explaining enzymatic catalysis in organic solvents.
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