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| 2. |
- Arja, Katriann, 1985-
(författare)
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Multimodal Porphyrin-Based Conjugates : Synthesis and characterization for applications as amyloid ligands, photodynamic therapy agents and chiroptical materials
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Organic compounds that interact both with certain biological targets and display specific photophysical properties can be utilized as molecular tools to visualize and possibly effect disease related processes taking place in living organisms. In this regard, porphyrins are a class of naturally occurring molecules that possess intriguingly interesting photophysical properties where they can act as luminescent probes by emitting detectable light, as well as photosensitizers in the light mediated therapy called photodynamic therapy. In this thesis, the porphyrin structure has been synthetically combined with other molecule classes to achieve compounds with desirable multimodal characteristics.Firstly, luminescent conjugated oligothiophenes (LCOs) that have extensively, and with great success, been utilized as fluorescent ligands for amyloid formations, have been conjugated to porphyrins to render oligothiophene porphyrin hybrids (OTPHs) comprising two optically active modalities. When applied as fluorescent amyloidophilic dyes for visualization of amyloid-β (Aβ), one of the pathological hallmarks in Alzheimer’s disease, an enhanced optical assignment of distinct aggregated forms of Aβ was afforded. Thus, properly functionalized OTPHs could give us more information about pathological processes underlying devastating disorders, such as Alzheimer’s disease. In addition, the OTPHs can be associated with synthetic peptides inducing peptide folding into certain three-dimensional helical structures giving rise to novel optically active materials.Secondly, this thesis also embraces porphyrins’ potential as photosensitizers in photodynamic therapy to kill cancer cells. Grounded on the prerequisites for an optimal photosensitizer, we designed porphyrin-based conjugates equipped with common carbohydrates for improved cancer cell selectivity and with a fluorinated glucose derivative, 2-fluoro 2-deoxy glucose, for advantageous metabolism in cancer cells. Furthermore, incorporation of a radioisotopic fluorine-18 atom into the glycoporphyrins could give the means for diagnostic use of the conjugates in positron emission tomography (PET).In order to tether together the above-mentioned molecular moieties in a controlled fashion, we developed a robust synthetic strategy for asymmetrical functionalization of porphyrin core. The method involves chlorosulfonation of this otherwise inert tetrapyrrolic structure, followed by alkynylation. Parallelly to amide coupling reactions, copper(I)-catalyzed alkyne azide cycloaddition is used for fast and high-yielding late-stage conjugations. Overall, this thesis demonstrates how combining different molecular moieties in synthetic organic chemistry yields novel molecules with combined and improved multimodal properties for biological and medicinal applications, guided by the design-by-function methodology.
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| 3. |
- Bayati, Shaghayegh
(författare)
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Autoantibody profiling in autoimmune diseases
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Autoimmune disease diagnosis and definition of prognosis can be challenging. Patients with the same autoimmune disease could present with very heterogeneous symptoms. Therefore, there is a need to understand the disease better to improve patients’ diagnosis, and classification, and tailor the treatment. Autoantibodies are a hallmark of many autoimmune diseases. They are antibodies produced by B cells and targeting self-antigens. Autoantibodies could be useful as diagnostic and prognostic markers of autoimmune disease.Protein arrays enable multiplex and high-throughput profiling of autoantibodies, therefore representing a good tool for autoantibody markers discovery and validation. This thesis presents the work performed to study autoantibodies in ANCA Associated Vasculitis (AAV) and Systemic Sclerosis (SSc) by employing planar and bead-based antigen arrays. Moreover, this thesis also includes the work done to optimize the application of a multiplex serology assay for the detection of anti-SARS-CoV-2 antibodies in saliva.In paper 1, we aimed to perform a broad autoantibody profiling in serum samples of AAV patients to search for new autoantibodies associated with the disease or disease subgroups and activity. The main result is related to the identification of anti-KIF5C antibodies at high prevalence in anti-MPO-positive patients and patients with microscopic polyangiitis (MPA). Anti-KIF4A also showed a higher prevalence in anti-MPO positive and MPA patients.In Paper 2 an in-depth autoantibody profiling was performed to identify autoantibodies as candidates for future relapse prediction in the plasma of AAV patients. We tested samples from patients classified as long-term remission-off-therapy (LTROT) and patients suffering future flares. Nine autoantibodies were found with higher reactivity in the relapse group. Among these, anti-ATF3 antibodies had increased reactivity in patients with kidney and ENT symptoms.In paper 3, plasma samples from SSc patients and controls were tested to detect autoantibodies associated with fibrosis. We identified eleven autoantibodies with increased prevalence in patients with systemic sclerosis compared to the control group. Eight of these autoantibodies are new in the context of systemic sclerosis and all bind to proteins that are involved in fibrosis. Among these, the anti-AKT3 was shown to be more reactive in patients with skin and lung fibrosis and anti-PIP4K2B in patients that were negative for the available diagnostic marker.Finally, in paper 4, a multiplex bead-based array serological assay was optimized to detect anti-SARS-CoV-2–specific IgG and IgA in saliva samples. This method was developed to measure antibodies, using SARS-CoV-2 spike and nucleocapsid proteins.In conclusion, the described work shows the application of the protein array technology to identify (auto)antibodies in different body fluids and within autoimmune diseases and SARS-CoV-2 infection. Moreover, we have identified autoantibody targets that are worth further investigation for their usefulness in better understanding some autoimmune conditions.
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- Elgland, Mathias, 1987-
(författare)
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Synthesis and application of β-configured [18/19F]FDGs : Novel prosthetic CuAAC click chemistry fluoroglycosylation tools for amyloid PET imaging and cancer theranostics
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Positron emission tomography (PET) is a non-invasive imaging method that renders three-dimensional images of tissue that selectively has taken up a radiolabelled organic compound, referred to as a radiotracer. This excellent technique provides clinicians with a tool to monitor disease progression and to evaluate how the patient respond to treatment. The by far most widely employed radiotracer in PET is called 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG), which is often referred to as the golden standard in PET. From a molecular perspective, [18F]FDG is an analogue of glucose where a hydroxyl group has been replaced with a radioactive fluorine atom (18F). It is well known that covalent attachment of carbohydrates (i.e., glycosylation) to biomolecules tend to improve their properties in the body, in terms of; improved pharmacokinetics, increased metabolic stability and faster clearance from blood and other non-specific tissue. It is therefore natural to pursuit the development of a [18F]fluoroglycosylation method where [18F]FDG is chemically conjugated to a ligand with high affinity for a given biological target (e.g., tumors or disease-associated protein aggregates).This thesis describes a novel [18F]fluoroglycosylation method that in a simple and general manner facilitate the conjugation of [18F]FDG to biological ligands using click chemistry. The utility of the developed [18F]fluoroglycosylation method is demonstrated by radiolabelling of curcumin, thus forming a tracer that may be employed for diagnosis of Alzheimer’s disease. Moreover, a set of oligothiophenes were fluoroglycosylated for potential diagnosis of Alzheimer’s disease but also for other much rarer protein misfolding diseases (e.g., Creutzfeldt-Jakob disease and systemic amyloidosis). In addition, the synthesis of a series of 19F-fluoroglycosylated porphyrins is described which exhibited promising properties not only to detect but also to treat melanoma cancer. Lastly, the synthesis of a set of 19F-fluorinated E-stilbenes, structurally based on the antioxidant resveratrol is presented. The E-stilbenes were evaluated for their capacity to spectrally distinguish between native and protofibrillar transthyretin in the pursuit of finding diagnostic markers for the rare but severe disease, transthyretin amyloidosis.
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| 5. |
- Johansson, Leif B.G.
(författare)
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Asymmetric Oligothiophenes : Chemical Evolution of Multimodal Amyloid Ligands
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Luminescent conjugated polymers (LCPs) and luminescent conjugated oligothiophenes (LCOs) can be used as molecular probes to study diseases associated with protein aggregation. The conventionally used dyes to study and detect protein aggregates, denoted amyloid, have been Congo red (CR) and Thioflavin T (ThT). In contrast to these amyloid ligands, LCOs offer the possibility to detect aggregated proteinaceous species occurring at earlier stages of amyloid formation as well as to distinguish different morphotypes of protein aggregates. The interaction between the LCOs and the protein deposits can be studied by fluorescence spectroscopy and microscopy both in vitro and ex vivo. In this thesis we report the development of multimodal asymmetric LCOs that can be utilized with two novel techniques, Surface Plasmon Resonance (SPR) and Positron Emission Tomography (PET), to study the interaction between LCO and amyloid fibrils in real time. With SPR, we have been able to determine binding affinities between LCO and amyloid, and with PET we have shown that radiolabelled LCOs can be used as a non-invasive method to study amyloid deposits in vivo. In addition, by alteration of the backbone (change of thiophene units), and of adding different side chains functionalities, we have shown that the properties of the amyloid ligands have a huge impact of the binding to different stages or forms of protein aggregates. By making asymmetrical LCOs, which can be attached to a surface, we also foresee a methodology that will offer the possibility to create a sensitive and selective detection method, and maybe lead to a lab-on-a-chip-application.
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| 6. |
- Krzymowska, Adriana, 1987-
(författare)
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Skattepliktiga överlåtelser i inkomstslaget kapital
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Capital gains and losses are taxed under the Income Tax Act (ITA) and occur when an asset is divested. The concept of divestment, which is regulated in §§ 3-10 in chapter 44 of the ITA, creates the scope of taxable events. Only those transactions that fall into the definition of divestments in accordance with §§ 3-10 in chapter 44 of the ITA are considered taxable events. Gifts, inheritance etc. are not considered divestments and are accordingly not taxed under the ITA.The objective of this doctoral project is to examine and analyze the concept of divestment in regards to the taxation of capital gains and losses. The purpose is to identify (a) what components, or requirements are necessary in order to form at transaction that is a divestment and (b) how those requirements are defined. This purpose requires an inventory of applicable law and practice as well as a study of the context of capital gains taxation. The study shows that an divestment is an act through which the former owner disposes of the asset in a definitive manner while directly or indirectly receiving sufficient compensation. The definitive disposal is characterized by that the rights and obligations associated with a particular asset are suspended in such a way that the ownership of the asset expires. This can occur if the asset is modified in such a way that the characteristic components of the asset are changed. If that happens the old asset is considered to have been exchanged for the new one. A divestment typically requires at least two parties.Legal certainty sets boundaries for the interpretation of the concept of divestment. The taxation should as far as possible be neutral, take into account if the transaction creates an (at least theoretical) ability to pay tax and if possible avoid solutions that create unnecessary lock-in effects. The context in which an assessment problem has occurred, principles of reciprocity, continuity, symmetry and consistency in the tax system should be taken into account when assessing unclear cases. In the assessment of whether there has been a divestment, the transaction should be broken up into segments and analyzed. In an unclear situation the assessment of whether a divestment was made or not must always be based on the motives of capital gains and loss taxation.
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| 7. |
- Lantz, Linda, 1985-
(författare)
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Synthesis of donor–acceptor–donor thiophene based ligands that can be utilized for optical assignment of pathological targets
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Thiophene based ligands represent a class of molecular reporters proven superior in discerning pathological targets involved in neurodegenerative diseases, as well as bacterial infection. By fluorometric detection that depends on the milieu surrounding the ligand these biological processes can be studied with fluorescence spectroscopy and hyper-spectral confocal microscopy. The binding of a thiophene-based ligand to a biological target can entail specific fluorescent read-out through the conformation-sensitive ligand. Thus, the photo-physical properties of these molecules and the optical connection of binding make them valuable tools in the study of pathological events. As optical detection of pathological phenomena can be realized through several fluorescence parameters, including changes in fluorescent intensity, wavelength shifts, energy transfer, or emission lifetime, molecular studies of pathological targets in several biological systems have been realized by employing thiophene-based ligands. For instance, utilization of conjugated polydisperse and monodisperse thiophene-based molecules has in several studies demonstrated detection of disease associated protein aggregates in vitro, ex vivo and in vivo. My doctoral studies have included the synthesis and characterization of thiophene based donor-acceptor-donor (D–A–D) molecules and evaluation of how changes in side-chain positions, molecular length and number of negatively charged carboxylates impact interaction with biological targets. This thesis describes the utilization of the D–A–D molecules as fluorescent ligands for protein aggregates associated with Alzheimer’s disease and optical assignment of specific bacteria. The design and synthesis of these novel D–A–D thiophene-based fluorophores, with alterations in back bone, distribution of side chains and negatively charged groups, have generated novel insights regarding the ligands chemical structure on ligand performance, by the assessment of binding mode of the respective ligand to distinct pathological entities. Furthermore, the D–A–D molecules hold alternative photo-physical properties compared to thiophene-based ligand and these optical properties of the ligands have been employed to provide new insights in questions regarding protein aggregate polymorphism in Alzheimer’s disease. Overall, by organic synthesis we have fine-tuned the properties of thiophene-based D-A-D molecules and evaluated how modifications affect interactions with distinct biological, pathological targets and we foresee that D–A–D thiophene-based ligands will expand the toolbox for studying pathological targets in neurodegenerative diseases, as well as bacterial infection.
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| 8. |
- Nilsson, Jenny A. U., 1978-
(författare)
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On methods for estimating oceanic flow
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this thesis was to estimate and possibly quantify ocean flow by utilizing conventional and novel observational methods as well as model results. Motionally induced voltages, from a cable-based observational system in the Baltic Sea, were analysed to determine their utility for ocean monitoring. The data set was examined as regards the influence of single- and multi-layer flow. Correlation analyses undertaken in the first study showed that the geoelectric installation is capable of providing good estimates of the net flow across the Visby-Västervik transect. The second study focused on possible effects of multi-layer flow on the signal. Comparisons were made with tidal-gauge geostrophic flow estimates, and a good agreement was found, except for a few brief winter periods characterized by significant discrepancies. The velocity fields from a three-dimensional model showed that these events coincided with strong surface and bottom currents, and hence the attenuated voltage signal was suggested as being caused by the non-uniform velocity distribution.The third study dealt with the deep-water flow through the Understen-Märket trench. Observational data indicated that this flow could be described by applying hydraulic theory. Since the passage is narrow compared to the internal Rossby radius of deformation, rotational effects could be neglected to lowest order. The theoretical predictions proved to agree well with the observational results.The final study examined the effects of the heat flux and the wind forcing on the circulation in Bahía de Concepción, Chile, where three field surveys were undertaken during the extended austral summer 2002. Hydrographic and current measurements were compared to local tidal-gauge records. Rough estimates of the barotropic and the baroclinic flow across the transect indicated an unusual vortex circulation during periods of weak wind forcing and strong surface heating; results which were corroborated by numerical simulations.
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| 9. |
- Nilsson, Sigrid, 1997-
(författare)
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Vasomotor Symptoms, Cardiovascular Risk and the Role of Physical Activity in Midlife Women
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: The menopausal transition is, for most women, accompanied by hot flushes and night sweats (i.e., vasomotor symptoms, VMS). VMS has been associated with a worsened cardiovascular risk profile, but whether VMS constitutes an independent risk marker for developing subclinical atherosclerotic cardiovascular disease (ASCVD) is still uncertain. Visceral adipose tissue (VAT) contributes more to systemic low-grade inflammation than abdominal subcutaneous adipose tissue (ASAT), enhancing atherosclerosis development. Physical activity is an effective behavioral strategy to maintain and improve cardiovascular health. Whether a resistance training intervention (RTI) could reduce low-grade inflammation and VAT volume in postmenopausal women with VMS remains unclear, and whether the RTI-associated effects could be maintained over time requires further investigation.Material and Methods: This thesis is based on three studies. Study 1 was conducted on a subset of participants from the cross-sectional population-based Swedish CArdioPulmonary BioImage Study (SCAPIS), including women 50-64 years of age. The women underwent comprehensive cardiovascular assessments and completed an extensive female-specific questionnaire. VMS was assessed on a 4-point scale. Subclinical ASCVD was detected via coronary computed tomography angiography (CCTA), computed tomography (CT), and carotid ultrasound. Study 2 is a sub-study of 65 postmenopausal women with VMS and low physical activity, randomized to either three days/week of an RTI or unchanged physical activity for 15 weeks. Women underwent anthropometric measurements, magnetic resonance imaging (MRI), and blood sampling at baseline and after 15 weeks. During the last followup contact in Study 2 after two years, 35 women agreed to attend an additional clinic visit to reevaluate cardiovascular risk markers, marking the inception of Study 3.Results: Of 2995 women included in Study 1, 14.2% reported severe VMS (n = 425), 18.1% moderate VMS (n = 543), and 67.7% no or mild VMS (n = 2027). Current or previous severe VMS, but not moderate VMS, was significantly associated with CCTA-detected coronary atherosclerosis, with odds ratio (OR) before and after multivariable adjustment 1.36, 95% confidence interval (CI) 1.08 – 1.72 and 1.33, 95% CI 1.02 – 1.72, respectively. This association was only present for >5 years durations of severe VMS or when the onset of severe VMS occurred before menopause. Adjustment for menopausal hormone therapy strengthened the association for women with severe VMS >5 years (OR 1.67, 95% CI 1.16 – 2.40). Women compliant with an RTI had compared to a control group (CG), decreased adiponectin (p < 0.01), ASAT (p < 0.01), VAT (p < 0.01), total abdominal adipose tissue (TAAT) (p < 0.01) and fat ratio (p <0.001). Furthermore, an RTI reduced moderate to severe VMS frequency to six months post-intervention compared to a CG, but did neither contribute to preserved cardiovascular health markers nor improved health-related quality of life (HRQoL) after two years compared to a CG.Conclusions: There is a need for extra vigilance regarding cardiovascular risk factors in the group of women suffering from severe VMS. Implementing a 15-week RTI in these women could counteract the VAT redistribution and alter the frequency of moderate to severe VMS with maintained effects up to six months.
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