| 11. |
- Arvidsson, Sandra, 1986-
(författare)
-
Cardiac function in hereditary transthyretin amyloidosis : an echocardiographic study
- 2016
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Hereditary transthyretin amyloidosis (ATTR) is a lethal disease in which misfolded transthyretin (TTR) proteins accumulate as insoluble aggregates in tissues throughout the body. A common mutation is the exchange of valine to methionine at place 30 (TTR V30M), a form endemically found in the northern parts of Sweden. The main treatment option for ATTR amyloidosis is liver transplantation as the procedure halts production of mutated transthyretin. The disease is associated with marked phenotypic diversity ranging from predominant cardiac complications to pure neuropathy. Two different types of fibril composition – one in which both fragmented and full-length TTR are present (type A) and one consisting of only full-length TTR (type B) have been suggested to account for some phenotypic differences. Cardiac amyloidosis is associated with increased myocardial thickness and the disease could easily be mistaken for other entities characterised by myocardial thickening, such as sarcomeric hypertrophic cardiomyopathy (HCM). The aims in this thesis were to investigate echocardiographic characteristics in Swedish ATTR amyloidosis patients, and to identify markers aiding in differentiating ATTR heart disease from HCM. Another objective was to examine the impact of fibril composition and sex on the phenotypic variation in amyloid heart disease.Methods: A total of 122 ATTR amyloidosis patients that had undergone thorough echocardiographic examinations were included in the studies. Analyses of ventricular geometry as well as assessment of systolic and diastolic function were performed, using both conventional echocardiographic methods and speckle tracking technique. ECG analysis was conducted in study I, allowing measurement of QRS voltage. In study I and study II ATTR patients were compared to patients with HCM. In addition, 30 healthy controls were added to study II.Results: When parameters from ECG and echocardiography were investigated, the results revealed that the combination of QRS voltage <30 mm (<3 mV) and an interventricular/posterior wall thickness quotient <1.6 could differentiate cardiac ATTR amyloidosis from HCM. Differences in degree of right ventricular involvement were also demonstrated between HCM and ATTR amyloidosis, where ATTR patients displayed a right ventricular apical sparing pattern whereas the inverse pattern was found in HCM. Analysis of fibril composition revealed increased LV wall thickness in type A patients compared to type B, but in addition type A women displayed both lower myocardial thickness and more preserved systolic function as compared to type A males. When cardiac geometry and function were evaluated pre and post liver transplantation in type A and B patients, significant deterioration was detected in type A but not in type B patients after liver transplantation.Conclusions: Increasing awareness of typical cardiac amyloidotic signs by echocardiography is important to reduce the risk of delayed diagnosis. Our classification model based on ECG and echocardiography could aid in differentiating ATTR amyloidosis from HCM. Furthermore, the apical sparing pattern found in the right ventricle may pose another clue for amyloid heart disease, although it requires to be studied further. Furthermore, we disclosed that type A fibrils, male sex and increasing age were important determinants of increased myocardial thickness. As type A fibril patients displayed rapid cardiac deterioration after liver transplantation other treatment options should probably be sought for this group of patients.
|
|
| 12. |
- Asplund, Pär, 1974-
(författare)
-
Percutaneous Balloon Compression for the Treatment of Trigeminal Neuralgia
- 2019
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background. Trigeminal neuralgia (TN) is a paroxysmal unilateral facial pain condition. That it is rather rare is of little comfort to those who are affected, as TN is often described as one of the worst pains known to mankind. Advanced age and multiple sclerosis (MS) are risk factors for developing TN. The first line of treatment is medical, primarily with carbamazepine. When medical treatment fails, as it does in many patients, there are several surgical options. One of the minimally invasive options, suitable for patients with comorbidity, is percutaneous balloon compression (PBC). Despite its introduction in the early 1980s, PBC is arguably the least well studied of the minimally invasive procedures for the treatment of TN.Aims. The aim of this thesis was to evaluate the efficacy of PBC, both overall and in MS-TN patients specifically. Further, it intended to identify and evaluate pre- and intraoperative parameters associated with the efficacy of PBC. It also investigated changes in sensory function after PBC, and identified side effects and complications associated with PBC. Finally, it sought to evaluate how efficacy, side effects and complications differed between PBC and another minimally invasive technique; percutaneous retrogasserian glycerol rhizotomy (PRGR).Methods. Cohorts of patients treated with PBC in Umeå and Stockholm, and with PRGR in Umeå, were followed retrospectively. Data from an existing database was combined with data from medical records, radiographs and telephone interviews.Results. After PBC, 90 % of the patients were completely pain free without medication for TN. The median time to recurrence of pain was 28 months. In patients with concurrent MS, the initial success rate was 67 % and the median time to recurrence was 8 months. In patients without MS, who had not previously been treated surgically, the initial success rate was 91 % and the median time to recurrence was 48 months. The procedure could, however, be repeated with good results. A good compression, indicated by a pear-shaped balloon as seen on intraoperative lateral radiograph, was crucial to achieve good pain relief. Postoperative hypoesthesia was present in the majority of patients, but after 3-6 months, sensibility was partly or fully normalized in most patients. Severe complications were rare, but included transient cardiac arrest, meningitis and dysesthesia. The side effects profile was favorable to that of percutaneous retrogasserian glycerol rhizotomy, in that the latter produced more cases of dysesthesia and decreased corneal sensibility. The efficacy of the two treatments were, however, not significantly different.Conclusions. PBC is an effective and relatively safe treatment option for patients with TN refractory to medical treatment. It deserves its place among the standard treatments for TN, and could be considered for those patients eligible for surgery for which open surgery is a less suitable option.
|
|
| 13. |
- Avican, Kemal, 1980-
(författare)
-
Persistent infection by Yersinia pseudotuberculosis
- 2015
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Enteropathogenic Yersinia species can infect many mammalian organs such as the small intestine, cecum, Peyer’s patches, liver, spleen, and lung and cause diseases that resemble a typhoid-like syndrome, as seen for other enteropathogens. We found that sublethal infection doses of Y. pseudotuberculosis gave rise to asymptomatic persistent infection in mice and identified the cecal lymphoid follicles as the primary site for colonization during persistence. Persistent Y. pseudotuberculosis is localized in the dome area, often in inflammatory lesions, as foci or as single cells, and also in neutrophil exudates in the cecal lumen. This new mouse model for bacterial persistence in cecum has potential as an investigative tool for deeper understanding of bacterial adaptation and host immune defense mechanisms during persistent infection. Here, we investigated the nature of the persistent infection established by Y. pseudotuberculosis in mouse cecal tissue using in vivo RNA-seq of bacteria during early and persistent stages of infection. Comparative analysis of the bacterial transcriptomes revealed that Y. pseudotuberculosis undergoes transcriptional reprogramming with drastic down-regulation of T3SS virulence genes during persistence in the cecum. At the persistent stage, the expression pattern in many respects resembles the pattern seen in vitro at 26°C. Genes that are up-regulated during persistence are genes involved in anaerobiosis, chemotaxis, and protection against oxidative and acidic stress, which indicates the influence of different environmental cues. We found that the Crp/CsrA/RovA regulatory cascades influence the pattern of bacterial gene expression during persistence. Furthermore, we show that ArcA, Fnr, FrdA, WrbA, RovA, and RfaH play critical roles in persistence. An extended investigation of the transcriptional regulator rfaH employing mouse infection studies, phenotypic characterizations, and RNA-seq transcriptomics analyses indicated that this gene product contributes to establishment of infection and confirmed that it regulates O-antigen biosynthesis genes in Y. pseudotuberculosis. The RNA-seq results also suggest that rfaH has a relatively global effect. Furthermore, we also found that the dynamics of the cecal tissue organization and microbial composition shows changes during different stages of the infection. Taken together, based on our findings, we speculate that this enteropathogen initiates infection by using its virulence factors in meeting the innate immune response in the cecal tissue. Later on, these factors lead to dysbiosis in the local microbiota and altered tissue organization. At later stages of the infection, the pathogen adapts to the environment in the cecum by reprogramming its transcriptome from a highly virulent mode to a more environmentally adaptable mode for survival and shedding. The in vivo transcriptomic analyses for essential genes during infections present strong candidates for novel targets for antimicrobials.
|
|
| 14. |
- Backman, Helena, 1979-
(författare)
-
Lung function and prevalence trends in asthma and COPD
- 2016
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Asthma and chronic obstructive pulmonary disease (COPD) are common obstructive airway diseases with a substantial burden in terms of morbidity, mortality and costs. Smoking is the single most important risk factor for COPD, and is associated with incident asthma. It is important to know if the prevalence of asthma and COPD is increasing or decreasing in the population in order to effectively allocate health care resources. The definitions of these diseases have varied over time which makes it difficult to measure changes in prevalence. The preferred method is to estimate the prevalence with the same procedures and definitions based on cross-sectional population samples with identical age distributions in the same geographical area at different time points. Measurements of lung function (spirometry) are required to diagnose COPD, and spirometry is used to evaluate disease severity and progress of both asthma and COPD, where observed values are compared to reference values. The most commonly used reference values in Sweden are published during the mid 1980s, and there are few evaluations of how appropriate they are today based on Swedish population samples. The aim of the thesis was to estimate trends in the prevalence of asthma and COPD in relation to smoking habits, and to evaluate and estimate reference values for spirometry.Methods: The project was based on population-based samples of adults from the Obstructive Lung Disease in Northern Sweden (OLIN) studies. Postal questionnaires were sent to large cohorts, recruited in 1992 (n=4851, 20-69 years), 1996 (n=7420, 20-74 years) and 2006 (n=6165, 20-69 years), respectively. The questionnaire included questions on respiratory symptoms and diseases, their comorbidities and several possible risk factors including smoking habits. Structured interviews and spirometry were performed in random samples of the responders to the 1992 and 2006 surveys, of which n=660 (in 1994) and n=623 (in 2009) were within identical age-spans (23-72 years). The trend in asthma prevalence was estimated by comparing the postal questionnaire surveys in 1996 and 2006, and the trend in COPD prevalence was estimated by comparing the samples participating in dynamic spirometry in 1994 and 2009, respectively. The prevalence of COPD was estimated based on two different definitions of COPD. Commonly used reference values for spirometry were evaluated based on randomly sampled healthy non-smokers defined in clinical examinations of participants in the 2006 postal questionnaire (n=501). The main focus of the evaluation was the global lung function initiative (GLI) reference values published in 2012, for which Z-scores and percent of predicted values were analysed. New sex-specific reference values for spirometry were estimated by linear regression, with age and height as predictors. These new OLIN reference values were also evaluated on a sample of healthy non-smokers identified in the population-based West Sweden Asthma Study.Results: Although the prevalence of smoking decreased from 27.4% to 19.1%, p<0.001, between 1996 and 2006, the prevalence of physician-diagnosed asthma increased from 9.4% to 11.6%, p<0.001. The prevalence of symptoms common in asthma such as recurrent wheeze did not change significantly between the surveys or tended to decrease, while bronchitis symptoms such as cough and sputum production decreased significantly. The evaluation of the GLI reference values showed that the predicted values were significantly lower compared to the observed values in Norrbotten, which makes the percent of predicted too high. This was especially true for FVC percent predicted with a mean of 106%. In general, the deviations were more pronounced among women. New OLIN reference values valid for the Norrbotten sample were modelled and showed a high external validity when applied on the sample from western Sweden. The prevalence of moderate to severe COPD decreased substantially over the 15-year period between 1994 and 2009, regardless of definition.Conclusions: In parallel with substantially decreased smoking habits in the population between 1996 and 2006, the prevalence of several airway symptoms decreased while the prevalence of physician-diagnosed asthma increased. These results suggest increased diagnostic activity for asthma, but may also suggest that the asthma prevalence has continued to increase. In contrast to asthma, the prevalence of COPD tended to decrease and moderate to severe COPD decreased substantially. The continuous decrease in smoking in Sweden during several decades prior to the study period is most likely contributing to these results. The evaluation of reference values showed that the GLI reference values were lower than the observed spirometric values in the population, especially for women, why the new up-to date reference values may be of importance for disease evaluation in epidemiology and in the health care as well.
|
|
| 15. |
- Bamyaci, Sarp, 1986-
(författare)
-
Multiple functions of YopN in the Yersinia pseudotuberculosis type III secretion system : from regulation to in vivo infection
- 2019
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The type 3 secretion systems (T3SSs) are virulence mechanisms used by various Gram-negative bacteria to overcome the host immunity. They are often target-cell contact induced and activated. Activation results in targeting of virulence effector substrates into host cells. One class of secreted substrates, translocators, are required for the intracellular targeting of the second class, the virulence effectors, into host target cells. T3SSs are mainly regulated at 2 levels; a shift from environmental to host temperature results in low level induction of the system whereas target cell contact further induces and activates the system. In the Yersinia T3SS, YopN, one of the secreted substrates, is involved in the latter level of activation. Under non-inducing conditions, YopN complexes with TyeA, SycN and YscB and this complex suppresses the T3SS via an unknown mechanism. When the system is induced, the complex is believed to dissociate and YopN is secreted resulting in the activation of the system. Earlier studies indicated that YopN is not only secreted but also translocated into target cells in a T3SS dependent manner. TyeA, SycN and YscB bind to the C-terminal and N-terminal YopN respectively but so far the central region (CR) of YopN has not been characterized. In this study we have focused on the function of the YopN central region.We therefore generated in-frame deletion mutants within the CR of YopN. One of these deletion mutants, aa 76-181, showed decreased early translocation of both YopE and YopH into infected host cells and also failed to efficiently block phagocytosis by macrophages. However, the YopNΔ76-181 protein was expressed at lower levels compared to wt YopN and also showed a slightly deregulated phenotype when expressed from its native promoter and were as a consequence not possible to use in in vivo infection studies.Therefore, we generated mutants that disrupted a putative coiled coil domain located at the very N-terminal of CR. Similar to YopNΔ76-181, these substitution mutants were affected in the early translocation of effector proteins. Importantly, they were as stable as wt YopN when expressed from the native promoter. One of these mutants was unable to cause systemic infection in mice indicating that YopN indeed also has a direct role in virulence and is required for establishment of systemic infection in vivo.
|
|
| 16. |
- Banday, Viqar, 1984-
(författare)
-
Metab-Immune analysis of the non-obese diabetic mouse
- 2016
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Type 1A diabetes mellitus or T1D is a chronic disease characterized by T cell mediated destruction of the insulin producing β cells in the islets of Langerhans. The classical symptoms include high glucose levels in urine and blood, polyuria, and polydipsia. Complications associated with T1D include blindness, amputations, and end-stage renal disease, and premature death. The non-obese diabetic (NOD) mouse, first described in 1980, is widely used as a model organism for T1D. T1D disease in the NOD mouse shares a number of similarities to human T1D including dependence on genetic and environmental factors. More than 30 disease associated gene regions or loci (termed insulin dependent diabetes, or Idd, loci) have been associated with T1D development in NOD. For some of these Idds, the corresponding region in human has been linked to the development of T1D in human.T1D, both in humans and mice, is recognized as a T cell mediated disease. However, many studies have shown the importance of both the metabolome and the immune system in the pathogenesis of the disease. Appearance of autoantibodies in the serum of patients is the first sign of pathogenesis. However, molecular and cellular events precede the immune attack on the β-cell immunity. It has been shown that patients who developed T1D have an altered metabolome prior to the appearance of autoantibodies. Although much is known about the pathogenesis of T1D, the contribution of the environment/immune factors triggering the disease is still to be revealed. In the present study both metabolic and immune deviations observed in the NOD mouse was analyzed. Serum metabolome analysis of the NOD mouse revealed striking resemblance to the human metabolic profile, with many metabolites in the TCA cycle significantly different from the non-diabetic control B6 mice. In addition, an increased level of glutamic acid was of the most distinguishing metabolite. A detailed bioinformatics analysis revealed various genes/enzymes to be present in the Idd regions. Compared to B6 mice, many of the genes correlated to the metabolic pathways, showed single nucleotide polymorphism (SNP), which can eventually affect the functionality of the protein. A genetic analysis of the increased glutamic acid revealed several Idd regions to be involved in this phenotype. The regions mapped in the genetic analysis harbor important enzymes and transporters related to glutamic acid. In-vitro islet culture with glutamic acid led to increased beta cell death indicating a toxic role of glutamic acid specifically towards insulin producing beta cells.In the analysis of the immune system, B cells from NOD mice, which are known to express high levels of TACI, were stimulated with APRIL, a TACI ligand. This resulted in enhanced plasma cell differentiation accompanied with increased class switching and IgG production. NOD mice have previously been shown to react vigorously to T-dependent antigens upon immunization. In this study we confirmed this as NOD mice showed an enhanced and prolonged immune response to hen egg lysozyme. Thus, serum IgG levels were significantly increased in the NOD mice and were predominantly of the IgG1 subtype. Immunofluorescence analysis revealed increased number of germinal centers in the NOD mice. Transfer of purified B and T cells from NOD to an immune deficient mouse could reproduce the original phenotype as seen in the NOD mice. Collectively, this thesis has analyzed the metabolomics and immune deviations observed in the NOD mice.
|
|
| 17. |
- Baudin, Maria, 1982-
(författare)
-
Rift Valley fever : consequences of virus-host interactions
- 2016
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Rift Valley fever virus (RVFV) is a mosquito-borne virus which has the ability to infect a large variety of animals including humans in Africa and Arabian Peninsula. The abortion rate among these animals are close to 100%, and young animals develop severe disease which often are lethal.In humans, Rift Valley fever (RVF) presents in most cases as a mild illness with influenza-like symptoms. However, in about 8% of the cases it progresses into a more severe disease with a high case fatality rate. Since there is such a high abortion rate among infected animals, a link between human miscarriage and RVFV has been suggested, but never proven.We could in paper I for the first time show an association between acute RVFV infection and miscarriage in humans. We observed an increase in pregnant women arriving at the Port Sudan Hospital with fever of unknown origin, and several of the patients experienced miscarriage. When we analysed their blood samples for several viral diseases we found that many had an acute RVFV infection and of these, 54% experienced a miscarriage. The odds of having a miscarriage was 7 times higher for RVFV patients compared to the RVFV negative women of which only 12% miscarried. These results indicated that RVFV infection could be a contributing factor to miscarriage.RVFV is an enveloped virus containing the viral glycoproteins n and c (Gn and Gc respectively), where Gn most likely is responsible for the initial cellular contact. The protein DC-SIGN on dendritic cells and the glycosaminoglycan heparan sulfate has been suggested as cellular receptors for RVFV, however other mechanisms are probably also involved in binding and entry. Charge is a driving force for molecular interaction and has been shown to be important for cellular attachment of several viruses, and in paper II we could show that when the charge around the cells was altered, the infection was affected. We also showed that Gn most likely has a positive charge at a physiological pH.When we added negatively charged molecules to the viral particles before infection, we observed a decreased infection efficiency, which we also observed after removal of carbohydrate structures from the cell surface.Our results suggested that the cellular interaction partner for initial attachment is a negatively charged carbohydrate. Further investigations into the mechanisms of RVFV cellular interactions has to be undertaken in order to understand, and ultimately prevent, infection and disease.There is currently no vaccine approved for human use and no specific treatments for RVF, so there is a great need for developing safe effective drugs targeting this virus. We designed a whole-cell based high-throughput screen (HTS) assay which we used to screen libraries of small molecular compounds for anti-RVFV properties. After dose-response and toxicity analysis of the initial hits, we identified six safe and effective inhibitors of RVFV infection that with further testing could become drug candidates for treatment of RVF. This study demonstrated the application of HTS using a whole-cell virus replication reporter gene assay as an effective method to identify novel compounds with potential antiviral activity against RVFV.
|
|
| 18. |
- Bay, Annika, 1970-
(författare)
-
Being physically active as an adult with congenital heart disease
- 2018
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Due to advances in medical and surgical care adults with congenital heart disease (CHD) is a growing and aging population, that now outnumbers the children with CHD. In general, adults with CHD have reduced aerobic exercise capacity and nearly half of the patients do not reach current recommendations on physical activity. It is known that a low level of physical activity is associated with an increased risk for acquired cardiovascular disease. Studies has shown that adults with CHD are at the same, or even higher risk as the general population, for developing acquired cardiovascular disease.Aim: The overall aim was to explore physical activity in adults with CHD with respect to associated factors, exercise self-efficacy and their own experiences.Methods: This thesis is based on four papers. Paper I included 471 adults with CHD from three tertiary care centres in Sweden. The participants completed questionnaires measuring patient reported outcomes (e.g. SF-12) including physical activity level. Paper II was based on data from 79 adults with CHD from two tertiary care centers in Sweden and 42 matched controls. All participants completed questionnaires on exercise self-efficacy and quality of life, wore an activity monitor during four consecutive days and performed muscle endurance tests. Paper I and II were of cross-sectional design and analyses were done using logistic regression. In paper III and IV data were collected through structured interviews for 14 participants. They were asked about their experiences of being physically active (paper III), what they considered as physical activities, and their experiences of enablers and barriers to physical activity (paper IV). Qualitative content analysis was used in papers III and IV.Results: Physical activity level (paper I) and exercise self-efficacy (paper II) were strongly associated with age where those over 40 years had a lower level of physical activity and lower exercise self-efficacy. Further, in paper I, it appeared that patient reported outcomes from SF-12 were strongly associated with physical activity level. In paper II, exercise self-efficacy was associated with performance in a muscle endurance tests. Paper III revealed an overall theme – It´s like balancing on a slackline that illustrates how adults with CHD described themselves in relation to physical activity. This overall theme consisted of four themes: (1) Being an adventurer – enjoying the challenges of physical activity; (2) Being a realist – adapting to physical ability; (3) Being a non-doer – lacking prerequisites for physical activity and (4) Being an outsider – feeling excluded depending on physical ability. In paper IV, the analysis revealed a description of what adults with CHD consider to be physical activity and considered as enablers and barriers for physical activity. Four categories appeared; physical aspects, psychological aspects, psychosocial aspects and environmental aspects. In the psychosocial aspect, social support and encouragement in childhood to be physically active and no restrictions from e.g. parents, teachers and health care increased physical activity in adulthood.Conclusions: Age, social support and accepting physical limitations seem to have an important impact regarding physical activity level and exercise self-efficacy. In contrast, the complexity of CHD and other medical factors appear to be of less importance for adults with CHD in relation to physical activity. In order to support adults with CHD to increase their physical activity and reach their full potential, it is important to explore and consider the various aspects that may affect physical activity in this population.
|
|
| 19. |
- Beckman Rehnman, Jeannette, 1969-
(författare)
-
New methods to evaluate the effect of conventional and modified crosslinking treatment for keratoconus
- 2015
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Today corneal crosslinking with ultraviolet-A photoactivation of riboflavin is an established method to halt the progression of keratoconus. In some cases, when the refractive errors are large and the visual acuity is low, conventional corneal crosslinking may not be sufficient. In these cases it would be desirable with a treatment that both halts the progression and also reduces the refractive errors and improves the quality of vision.Aims: The aims of this thesis were to determine whether mechanical compression of the cornea during corneal crosslinking for keratoconus using a sutured rigid contact lens could improve the optical and visual outcomes of the treatment, and also to find methods to evaluate the effect of different corneal crosslinking treatment regimens.Methods: In a prospective, open, randomized case-control study, 60 eyes of 43 patients with progressive keratoconus, aged 18-28 years, planned for routine corneal crosslinking, and a corresponding age- and sex-matched control group was included. The patients were randomized to conventional corneal crosslinking (CXL; n=30) or corneal crosslinking with mechanical compression of the cornea during the treatment (CRXL; n=30).Biomicroscopy, autorefractometry, best spectacle corrected visual acuity, axial length measurement, Pentacam® HR Scheimpflug photography, pachymetry, intraocular pressure measurements and corneal biomechanical assessments were performed before treatment (baseline) and at 1 month and 6 months after the treatment.One of the articles evaluated and compared the optical and visual outcomes between CXL and CRXL, while the other three articles focused on methods to evaluate treatment effects. In Paper I, the corneal light scattering was manually quantified from Scheimpflug images throughout the corneal thickness at 8 measurements points, 0.0 to 3.0 mm from the corneal centre, in patients treated with CXL. In Paper IV the corneal densitometry (light scattering) was measured with the Pentacam® HR software, in 4 circular zones around the corneal apex and at 3 different depths of the corneal stroma, in both CXL and CRXL treated corneas. Paper III quantified the biomechanical effects of CXL in vivo.Results: Corneal light scattering after CXL showed distinctive spatial and temporal profiles and Applanation Resonance Tonometry (ART) -technology demonstrated an increased corneal hysteresis 1 and 6 months after CXL. When comparing the refractive and structural results after CXL and CRXL, CRXL failed to flatten the cornea, and the treatment did not show any benefits to conventional CXL treatment, some variables even indicated an inferior effect. Accordingly, the increase in corneal densitometry was also less pronounced after CRXL.Conclusions: Analysis of corneal light scattering/densitometry shows tissue changes at the expected treatment location, and may be a relevant variable in evaluating the crosslinking effect. ART -technology is an in vivo method with the potential to assess the increased corneal hysteresis after CXL treatment. By refining the method, ARTmay become a useful tool in the future. Unfortunately, CRXL does not improve the optical and visual outcomes after corneal crosslinking. Possibly, stronger crosslinking would be necessary to stabilize the cornea in a flattened position.
|
|
| 20. |
- Bendix, Marie, 1971-
(författare)
-
Neuroendocrine studies in patients with affective disorders
- 2019
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Affective disorders are common and a major cause for increased disability and mortality worldwide. Exogenous stressors and biological variables, including neuroendocrine factors, are assumed to contribute to an increased vulnerability to mood dysregulation. Affective disorders are highly heterogeneous and different neuroendocrine systems may play differential roles in the phenotypic expression of affective disorders in men and women.Aims: The overall aim of this thesis was to study three neuroendocrine systems in relation to underlying behavioral endophenotypes (personality traits, self-directed and interpersonal violence, and psychiatric symptoms) in patients with affective disorders.Methods: In Study I oxytocin plasma levels were assessed in 101 general psychiatric outpatients and followed-up in 36 patients after one month. Patients underwent diagnostic, symptomatic, and personality trait assessments.In Study II insulin and glucagon levels in plasma and cerebrospinal fluid (CSF) were assessed in 28 patients hospitalized after a recent suicide attempt and 19 healthy controls. Study persons were assessed regarding lifetime violence expression, psychiatric diagnoses and symptoms.In Study III serum levels of allopregnanolone, progesterone and estradiol were assessed in 14 women with severe postpartum depression and psychosis who, as previously reported, responded with rapid symptom remission during sublingual estradiol treatment. Hormonal and symptomatic assessment were performed before and after 4 weeks of estradiol treatment. 28 healthy postpartum controls were included for baseline comparison.Results: I) Plasma oxytocin levels were positively associated with personality traits of impulsiveness (monotony avoidance) and negative emotionality (psychic anxiety) with potential gender differences.II) Patients after suicide attempt had higher insulin (plasma and CSF) and lower glucagon levels (CSF) than healthy controls. Insulin levels (plasma and CSF) were higher and glucagon levels (plasma) were lower in patients and controls with higher levels of prior violence expression.III) Serum allopregnanolone decreased in women with postpartum depression and psychosis during estradiol treatment. The ratio between allopregnanolone and progesterone was significantly lower in patients than in healthy controls at baseline and it remained unchanged after symptom remission.Conclusion: Behavioral endophenotypes, rather than categorical diagnoses, of affective disorders were associated with neuroendocrine variation in three different cohorts of patients with affective disorder. Hormonal variation pointed towards an association with trait, rather than state like facets of affective behavior, constituting potential vulnerability markers for affective dysregulation.
|
|
