| 1. |
- Andréasson, Frida
(författare)
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Doing informal care : Identity, couplehood, social health and information and communication technologies in older people’s everyday lives
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of the thesis has been a) to analyse how informal care influences the identity of carers and care recipients, their sense of couplehood and social health, and b) to explore the use of Information and Communication Technology (ICT) in the context of informal care and the everyday lives of older people. Study I focused on how older carers conceptualised their identity as carers on a Swedish online social forum, using a netnographic methodology. The findings indicated a change in self-perception as the carer role was acquired. Carers’ capacities were filtered through the needs of the care recipient, making their carer identities into invisible selves. The findings revealed that online communication had the potential to create a virtual space of social recognition. Study II aimed to reflect on carers’ experiences of participation in a co-design process consisting of user group sessions with carers and researchers. The goal was to develop a web-based support programme for carers. The findings emphasised a need to consider carers’ lifeworlds and to develop flexible human-centred design methodologies, that are able to balance carers’ needs and ideas with proposed research outcomes. Studies III and IV utilised an ethnographic methodology. In study III, the notion of couplehood in informal care was analysed. The findings showed that in the process of becoming a carer and a care recipient previous (often gendered) responsibilities were re- negotiated and new practicalities emerged. Although these changes were understood as a natural part of family life, they nevertheless led to changes in the (power) balance between spouses, expressed in terms of a professionalised relationship and a sense of social isolation. ICT was used as a means to get a respite from caring and uphold a social connection with others. In study IV, the social implications and consequences of spousal informal care and carers and care recipients’ experiences of illness and the ill body was explored. The findings showed that the participants experienced barriers to living life as before. Thoughts about or the presence of ill and “leaking” bodies thus lead to “self-chosen” social isolation or social distancing by others. The thesis highlights that informal care needs to be understood as an identity forming practice, having a significant impact on involved parties’ sense of couplehood, their social health and that ICT can contribute to ease carers’ and care recipients’ daily life.
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| 2. |
- Andréasson, Måns, 1994-
(författare)
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Redefining the essential molecular aspects that drive interactions between small molecules and G-quadruplex DNA
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- G-Quadruplex (G4) structures are secondary nucleic acid structures located in guanine-rich regions of DNA and RNA sequences, involved in gene regulation and cellular maintenance. Efforts to target G4s in a therapeutic setting are scarce, mainly due to vague details about the binding interactions between the ligands and the G4 structure combined with the lack of emphasis on drug-like properties early in the ligand development process. Furthermore, the ability to target specific G4 structures with small drug-like molecules remains a big challenge to overcome in the field. In this thesis, extensive organic synthesis developments coupled with computational-aided design and orthogonal in vitro assays has been used in tandem to reveal in-depth knowledge about ligand-to-G4 interactions. First, a macrocyclic approach was applied to design and discover novel G4 ligands which showed that macrocycles offer a solid foundation for ligand design. Next, computational tools to optimise the macrocyclic molecular conformation were used based on the macrocycles' abilities to stack on the G4 surface. In addition, macrocyclic, and non-macrocyclic ligands that bound G4 with high potency were shown to correlate with electron-deficient electrostatic potential (ESP) maps. The frequent inclusion of cationic residues in G4 ligands and their enhancement on ligand-to-G4 binding was, thereof, ascribed to their impact on the electrostatic character of the ligands' arene-arene interactions with the G4 surface, and not through direct electrostatic ionic interactions. In addition, the dispersion energetic component in the arene-arene interactions between the G4 ligand and the G4 was discovered to be paramount for ligand-to-G4 binding. The implementation of these descriptors in practice resulted in the discovery of potent G4 binders with adequate pharmacokinetic (PK) properties, accentuating the significance of understanding the molecular interactions between ligands and G4s in rational ligand design. Finally, a G4 ligand conjugated to an oligonucleotide was demonstrated as a modular approach to achieve selective binding of a ligand to a specific G4 structure.
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| 3. |
- Masser, Anna E., 1987-
(författare)
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Controlling protein homeostasis through regulation of Heat shock factor 1
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In order to thrive in a changing environment all organisms need to ensure protein homeostasis (proteostasis). Proteostasis is ensured by the proteostasis system that monitors the folding status of the proteome and regulates cell physiology and gene expression to counteract any perturbations. An increased burden on the proteostasis system activates Heat shock factor 1 (Hsf1) to induce transcription of the heat shock response (HSR), a transiently induced transcriptional program including core proteostasis genes, importantly those encoding the Hsp70 class of molecular chaperones. The HSR assists cells in counteracting the harmful effects of protein folding stress and restoring proteostasis. The work presented in this thesis is based on experiments with the Saccharomyces cerevisiae (yeast) model with the overall goal of deciphering how Hsp70 detects and impacts on perturbations of cellular proteostasis and controls Hsf1 activity.In Study I we describe the fundamental mechanism by which Hsp70 maintains Hsf1 in its latent state by controlling its ability to bind DNA. We found that Hsf1 and unfolded proteins directly compete for binding to the Hsp70 substrate-binding domain. During heat shock the pool of unfolded proteins mainly consist of misfolded, newly synthesized proteins. Severe out-titration of Hsp70 by misfolded substrates resulted in unrestrained Hsf1 activity inducing a previously uncharacterized genetic hyper-stress program. More insight into regulation of Hsp70 availability was gained in Study II where the two splice isoforms of the Hsp70 nucleotide exchange factor Fes1 were characterized. We found that the cytosolic splice isoform Fes1S is crucial to release unfolded proteins from Hsp70 and that impaired release results in strong Hsf1 activation.In Study III we developed methodology to easily measure the rapid changes in Hsf1 activity upon proteostatic perturbations and to monitor protein turnover using the novel bioluminescent reporter NanoLuc optimized for yeast expression (yNluc). In Study IV we report that yNluc also functions as an in vivo reporter that detects severe perturbations of de novo protein folding by its failure to fold to an active conformation under such conditions.Finally, in Study V we investigated how organellar proteostasis impacts on the availability of cytosolic Hsp70. We found that a lowered mitochondrial proteostatic load as a result of high translation accuracy extended lifespan and improved cytosolic proteostasis capacity, evidenced by more rapid stress recovery and less sensitivity to toxic misfolded proteins. In contrast, lowered mitochondrial translation accuracy decreased lifespan and impaired management of cytosolic protein aggregates as well as elicited a general transcriptional stress response.Taken together, the findings presented in this thesis advance our understanding of how the regulatory mechanisms of the proteostasis system function. Furthermore, they provide novel methodology that will facilitate future studies to improve our understanding how cells integrate internal and external stress cues to control proteostasis.
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| 4. |
- Molnar, Anna
(författare)
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Structure and Function of the Retina in Children Born Extremely Preterm and in Children Born At Term
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Optical coherence tomography (OCT), multifocal electroretinography (mfERG) and full-field electroretinography (ffERG) give important information about retinal structure and function.Purpose: To collect normative data of macular Cirrus Spectral domain (SD)-OCT assessments and of mfERG measurements of healthy children (papers I and II). To assess the macular thickness with Cirrus SD-OCT and the retinal function with ffERG in 6.5-year-old children born extremely preterm and in children born at term (papers III and IV).Methods: Study participants aged 5-15 years and living in Uppsala County were randomly chosen from the Swedish Birth Register (papers I and II). In papers III and IV, the study participants consisted of children born extremely preterm and children born at term – all were aged 6.5 years. In paper III, the children were living in Stockholm and Uppsala health care regions and, in paper IV, in Uppsala health care region only. Macular thickness was assessed with Cirrus SD-OCT and macular function with mfERG, using the Espion Multifocal system and DTL-electrodes. The retinal function was assessed with ffERG and DTL-electrodes, using the Espion Ganzfield system.Results: Altogether, 58 children participated in paper I and 49 children in paper II. In paper I, the repeatability and reproducibility of the OCT assessments were good. In paper II, the results of the mfERG measurements were in accordance with retinal cone density and there were no significant differences between the right and left eyes. In paper III, 134 preterm children and 145 children born at term constituted the study population. The central macular thickness was significantly thicker in the preterm group than in the control group. Within the preterm group, gestational age (GA), former retinopathy of prematurity (ROP) and male gender were all important risk factors for an increased macular thickness. In paper IV, 52 preterm children and 45 control children constituted the study population. Significantly lower amplitudes and prolonged implicit times of the combined rod and cone responses, as well as of the isolated cone responses, were found in the preterm group when compared with the control group. In paper IV, there was no association between GA, ROP or male gender and the ffERG assessments.Conclusion: Normative data of Cirrus SD-OCT and mfERG assessments were reported. The results of the assessments were reliable. Children aged 6.5 years, born extremely preterm, had a significantly thicker central macula and both rod and cone function were significantly reduced in comparison to children born at term. ROP had an influence on retinal structure but not retinal function in the present cohorts. Our results suggest that retinal development is abnormal in children born extremely preterm. Long-term follow-up studies are necessary in order to evaluate the functional ophthalmological outcome in this vulnerable population of children growing up today.
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| 5. |
- Nixon Andreasson, Anna
(författare)
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Self-rated health : biobehavioral determinants with focus on inflammatory factors
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Self-rated (subjective) health is an independent predictor of future mortality, but neither the mechanisms behind this relation nor the biological determinants of poor self-rated health are known. Inflammatory cytokines give rise to a sickness response which includes fatigue, malaise, anhedonia and pain, resembling factors that are known to impact negatively on self-rated health. It is therefore possible that cytokines that cause a sickness response are important mediators in subjective health perception. This thesis investigated biobehavioral determinants of self-rated health, with a primary focus on inflammatory cytokines. The study populations included women patients from a primary health care center (Study I), women from a population based study on memory and aging in Umeå (Study II), men and women from a population based prospective study in Stockholm (Study III), and men in a laboratory study on the effects of experimentally restricted sleep (Study IV). A main finding was that higher (or increased) levels of inflammation related cytokines were associated with poor (or deteriorated) self-rated health; interleukin (IL)-1β, IL-1ra and tumor necrosis factor (TNF)-α in study I, and IL-6 in study II and IV. The observed association between higher levels of cytokines and poor self-rated health was shown to be stronger with increased age. Of psychological factors, positive affect turned out to be a more important determinant of self-rated health as compared to negative affect. In study III, the relation between leptin, a cytokine-like marker for available energy in the body, and self-rated health was investigated. Higher levels of leptin were associated to poor self-rated health in men, while instead predicting better future self-rated health in women. Moreover, self-rated health was associated to further sick-leave in both men and women. In study IV, subjective health - framed to represent the prevailing day - deteriorated gradually when sleep was restricted to 4 h per night, and returned to baseline levels after two days of recovery. This decrease in subjective health was significantly correlated with increased levels of circulating IL-6. This thesis presents increased support for an immune component of subjectively perceived health. It also implies that more short-term perspectives, e.g. in relation to changes in health behaviors such as sleep, should be taken into account when understanding subjective health perception. The results are of importance for understanding the psychobiological underpinnings of self-rated health and may give clues to explain its well-established association to future health.
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