| 1. |
- Pennells, Lisa, et al.
(författare)
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Equalization of four cardiovascular risk algorithms after systematic recalibration : individual-participant meta-analysis of 86 prospective studies
- 2019
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 0195-668X .- 1522-9645. ; 40:7, s. 621-
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Tidskriftsartikel (refereegranskat)abstract
- Aims: There is debate about the optimum algorithm for cardiovascular disease (CVD) risk estimation. We conducted head-to-head comparisons of four algorithms recommended by primary prevention guidelines, before and after ‘recalibration’, a method that adapts risk algorithms to take account of differences in the risk characteristics of the populations being studied.Methods and results: Using individual-participant data on 360 737 participants without CVD at baseline in 86 prospective studies from 22 countries, we compared the Framingham risk score (FRS), Systematic COronary Risk Evaluation (SCORE), pooled cohort equations (PCE), and Reynolds risk score (RRS). We calculated measures of risk discrimination and calibration, and modelled clinical implications of initiating statin therapy in people judged to be at ‘high’ 10 year CVD risk. Original risk algorithms were recalibrated using the risk factor profile and CVD incidence of target populations. The four algorithms had similar risk discrimination. Before recalibration, FRS, SCORE, and PCE over-predicted CVD risk on average by 10%, 52%, and 41%, respectively, whereas RRS under-predicted by 10%. Original versions of algorithms classified 29–39% of individuals aged ≥40 years as high risk. By contrast, recalibration reduced this proportion to 22–24% for every algorithm. We estimated that to prevent one CVD event, it would be necessary to initiate statin therapy in 44–51 such individuals using original algorithms, in contrast to 37–39 individuals with recalibrated algorithms.Conclusion: Before recalibration, the clinical performance of four widely used CVD risk algorithms varied substantially. By contrast, simple recalibration nearly equalized their performance and improved modelled targeting of preventive action to clinical need.
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| 2. |
- 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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| 3. |
- Jans, Jenny, 1984-
(författare)
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Causes and Consequences of Early-life Conditions : Alcohol, Pollution and Parental Leave Policies
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Essay I: This paper studies the effect of air pollution on infant health in Sweden. Combining register panel data on birth outcomes and family characteristics with pollution data, I estimate the effect of particulate matter (PM10) on several birth outcomes that previously have been shown to be predictive of future outcomes. The results suggest that pollution adversely affects infant health (birth weight and gestational length). Moreover, quantile estimates suggests that the effects are larger in the lower tail of the health distribution. The effect is stronger both among children from low income households and among children born to mothers who smoke. I also find suggestive evidence of non-linearities in the relationship between PM10 and health at birth.
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| 4. |
- 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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| 5. |
- Mashayekhy Rad, Farshid, 1973-
(författare)
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Analytical methods for biomolecules involved in atmospheric aerosol formation in the Arctic
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the Arctic, increasing ice-free conditions and nutrients freed from the melting ice must strongly influence the marine life. Aerosol emissions from microbiological marine processes may affect the low clouds and fogs over the summer Arctic, which in turn have effects on the melting of sea ice. The radiative properties of the high Arctic low clouds are strongly dependent on the number concentration of airborne water-soluble particles, known as cloud condensation nuclei (CCN). If the effects of CCN on cloud optical properties is to be fully understood it is important to be able to specify the source and concentrations of the Arctic aerosol particles.Previous studies in the Arctic have indicated that organic material formed in the uppermost ocean surface is transferred to the atmosphere and plays a potentially very important role in the aerosol-fog/cloud cycle. However, many aspects of this process remain unverified and chemical characterisation of targeted groups of biomolecules is still notably fragmentary or non-existing. Investigation of biomolecules, particularly amino acids, peptides and proteins together with mono- and polysaccharides and fatty acids in the airborne aerosol, and their relative contributions to fog/cloud water, requires development of an array of “cutting edge” analytical techniques and methods.In this thesis, electrospray ionization mass spectrometry was used for all applications and target biomolecules. The measurements in the Arctic turned out to be challenging due to the highly complex, salty matrices, combined with very low concentration and high diversity of the target biomolecules, and each step of the analytical chain needed careful consideration. To increase the detectability of the very low levels of polysaccharides and proteins in aerosols, these compounds were hydrolyzed to their subunits, monosaccharides and amino acids. Monosaccharides were separated using hydrophilic interaction chromatography, which was beneficial for their detection in electrospray ionization mass spectrometry. Amino acids were derivatized, yielding improvement in reversed-phase chromatographic separation, ionization efficiency as well as selectivity. For fatty acids in a sea surface sample, a novel fast screening method was developed, utilizing travelling-wave ion mobility separation as an orthogonal technique connected to mass spectrometry. In addition, a method for the detection of wood burning as an anthropogenic source of aerosols was developed, utilizing anhydrous monosaccharides as markers. This method can be used in the upcoming expeditions for source apportionment studies.The results from the analyses of the aerosol and fog water samples, collected over the summer pack ice north of 80 °N, show that both total polysaccharides and total proteinaceous compounds (sum of proteins, peptides and amino acids) occurred at the pmol m-3 to nmol m-3 level. Interestingly, the levels were found higher between different years, suggested to be coupled to less ice coverage and thus to a higher biological activity in the ocean surface. The highest concentrations of polysaccharides, as an indication of marine polymer gels, were found during the summer over the pack ice area. In addition, a pilot source apportionment study was carried out combining the measurement of different molecular tracers, used as source markers. This study indicates the seasonality and abundance of marine polymer gels as an important feature of the Arctic Ocean connected to the melting and freezing of sea ice. It should be further studied how the abundance of these gels, which have a high potential for cloud droplet activation, affect the melting and freezing of the perennial sea ice.Given the successful development of analytical methods for targeted groups of biomolecules, this thesis has supported the importance of biomolecules as CCN and for cloud formation in the Arctic. Less ice coverage may further increase the number of biomolecular CCN which could change the radiative balance, by the formation of more low-level clouds. Overall, more studies are required to further unravel the complex relationship of biogenic sources, atmospheric chemistry and meteorology to assess the impact of climate change on the Arctic.
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| 6. |
- Mikus, Maria, 1986-
(författare)
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Array-based identification of disease-associated proteins
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- To increase our understanding of the human body in both health and disease, proteins can be studied in samples such as plasma and serum to provide a molecular profile of the physiological status. In the work presented in this thesis, array-based methods were used to study associations of protein and autoantibody profiles with disease. The methods included antibody suspension bead arrays for protein profiling and planar antigen arrays or antigen suspension bead arrays for autoantibody profiling.In Paper I, we studied protein levels in the context of the neurodegenerative disease amyotrophic lateral sclerosis (ALS). We identified three proteins, NEFM, RGS18 and SLC25A20, to be significantly elevated in patients with ALS. We also evaluated the diagnostic potential of these proteins, reaching areas under the curves (AUCs) between 0.78 and 0.86 for each of the three proteins individually.In Paper II, drug-induced liver injury (DILI) cases and controls were studied in four independent cohorts of longitudinal and cross-sectional design and covering a range of drugs. The protein FABP1 was elevated in DILI cases upon initiation of treatment whereas CDH5 were elevated before treatment. Furthermore, we compared FABP1 with the clinically measured alanine aminotransferase (ALT), and identified some aspects in which FABP1 was superior: tissue distribution – FABP1 was not found in skeletal and heart muscle tissue, injuries in which can cause elevations of ALT; kinetics – FABP1 is smaller and has a lower half-life compared to ALT. Both of these circumstances mean that FABP1 as a biomarker has the potential to more accurately reflect ongoing injury.In Paper III, asthma of different severities, chronic obstructive pulmonary disease and healthy controls from two independent cohorts were studied. The levels of ten proteins were verified to be significantly elevated in severe asthma compared to both mild-to-moderate asthma and healthy controls in both cohorts. We also clustered asthma patients based on their protein profiles and identified six subgroups that could help to guide the appropriate treatment.In Paper IV, atopic dermatitis (AD) of different severities and healthy controls were studied. Increased autoantibody reactivity to four antigens, KRTAP17-1, HSPA4, S100A12 and S100Z, were observed in AD patients or in any of the two severity disease subgroups compared to controls.In summary, the work included in this thesis highlights the applicability of protein array-based methods in various contexts and in studying various research questions. Disease-associated proteins were identified and further studies will determine their utility.
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| 7. |
- Nilsson Broberg, Malin
(författare)
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Metabolite Profiling of Drugs using Mass Spectrometry : Identification of analytical targets for doping control and improvements of the metabolite search process
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Doping is defined as the use of prohibited substances or methods by the World Anti-Doping Agency and the aim with doping control analysis is to detect the use of these illicit substances or methods. Substances that are prohibited in human or equine sports have either a positive or negative impact on the performance. Since administered drugs generally are metabolized to a varying degree and thereby not only excreted in their original form, their metabolite profiles are of high interest because drug metabolites may be present in the body for a longer time than the administered drug itself. Thereby detection of metabolites can improve the window of detection. Unfortunately, the metabolite profiles of non-approved drugs that are mainly available on the Internet, such as Selective Androgen Receptor Modulators (SARMs) are often unknown. This thesis consists of four papers that all encompass drug metabolite profiling either in vivo, in vitro or in a combination, utilizing separation with liquid chromatography and detection with high resolution mass spectrometry. In paper I and II, the equine in vivo metabolite profiles of the two SARMs ACP-105 and LGD-3303 were investigated and the results showed that using drug metabolites as analytical targets can prolong the detection time. For ACP-105, the in vivo metabolite profile was compared with different incubation models such as liver microsomes, S9 fractions and the fungus Cunninghamella elegans. The in vivo and in vitro metabolite profiles showed an interesting overlap for several metabolites, demonstrating the importance and usefulness for in vitro methods in doping control, especially since microsome incubates are allowed as reference material. An optimization of microsome incubation conditions utilizing experimental design was presented in paper III and IV, showing that the optimized conditions greatly impacted the yield of drug metabolites, but also that the optimal conditions are substance dependent. In paper III, a multivariate data analysis search tool utilizing OPLS-DA was presented, which greatly simplified the in vitro drug metabolite identification process of ACP-105 and the results showed relevance in comparison with human in vivo metabolites.In conclusion, several new analytical targets with improved detectability for equine and human doping control have been presented, where the drug metabolite profile showed to be of great importance. All together, these new analytical targets, the optimized microsome incubation conditions for improved metabolite yield and the search tool that aids the metabolite investigation through multivariate data analysis, have made a positive contribution to the doping control area.
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| 8. |
- Nilsson, Lena Maria, 1965-
(författare)
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Sami lifestyle and health : epidemiological studies from northern Sweden
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this PhD thesis was to expand the current knowledge of “traditional Sami” diet and lifestyle, and to test aspects of the Sami diet and lifestyle, specifically dietary pattern, macronutrient distribution and coffee consumption, in population-based epidemiological studies of mortality and incident cardiovascular disease and cancer in a general population.In Paper I, semi-structured interviews were conducted with 20 elderly Sami concerning their parent’s lifestyle and diet 50-70 years ago. Questionnaire data from 397 Sami and 1842 matched non-Sami were also analyzed, using non-parametric tests and partial least square methodology. In Papers II-IV, mortality data and incident cancer data for participants in the Västerbotten Intervention Program (VIP) cohort were used for calculations of hazard ratios by Cox regression. In Paper II, a Sami diet score (0-8 points) was constructed by adding one point for each intake above the median for red meat, fatty fish, total fat, berries and boiled coffee, and one point for each intake below the median for vegetables, bread and fibre. In Paper III, deciles of energy-adjusted carbohydrate (descending) and protein (ascending) intake were added to create a Low-Carbohydrate, High-Protein (LCHP) score (2-20 points). In Paper IV, filtered and boiled coffee consumption was studied in relation to incident cancer. In Paper V, a nested case-control study of filtered and boiled coffee consumption and acute myocardial infarction, risk estimates were calculated by conditional logistic regression.Surprisingly, fatty fish may have been more important than reindeer meat for the Sami of southern Lapland in the 1930’s to 1950’s, and it is still consumed more frequently by reindeer-herding Sami than other Sami and non-Sami. Other dietary characteristics of the Sami 50-70 years ago and present-day reindeer-herding Sami were high intakes of fat, blood, and boiled coffee, and low intakes of bread, fibre and cultivated vegetables (Paper I). Stronger adherence to a “traditional Sami” diet, i.e. a higher Sami diet score, was associated with a weak increase in all-cause mortality, particulary apparent in men (Paper II). A diet relatively low in carbohydrates and high in protein, i.e. a high LCHP score, did not predict all-cause mortality compared with low LCHP score, after accounting for saturated fat intake and established risk factors (Paper III). Neither filtered nor boiled coffee consumption was associated with cancer for all cancer sites combined, or for prostate or colorectal cancer. For breast cancer, consumption of boiled coffee ≥4 versus <1 occasions/day was associated with a reduced risk. An increased risk of premenopausal and a reduced risk of postmenopausal breast cancer were found for both total and filtered coffee. Boiled coffee was positively associated with the risk of respiratory tract cancer, a finding limited to men (Paper IV). A positive association was found between consumption of filtered coffee and the risk of acute myocardial infarction in men (Paper V).In conclusion, the findings of Paper I, in particular the relative importance of fatty fish compared to reindeer meat in the “traditional Sami” diet of the 1930’s-1950’s, suggest that aspects of cultural importance may not always be of most objective importance. The findings of Papers II-V generally did not support health benefits for the factors studied. The relatively good health status of the Sami population is therefore probably not attributable to the studied aspects of the “traditional Sami” lifestyle, but further investigation of cohorts with more detailed information on dietary and lifestyle items relevant for “traditional Sami” culture is warranted.
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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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| 10. |
- Olsson, Hans
(författare)
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Stage T1 Urinary Bladder Carcinoma : Investigation of A Population-Based Cohort
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Approximately 2 300 new cases of urinary bladder carcinoma (UBC) are diagnosed every year in Sweden. This type of cancer is characterized as a long-standing disease with a high risk of recurrence and progression from an indolent to a more aggressive course. UBC occurs in a non-muscle-invasive form (stages Ta and T1), which is treated mainly with local resection and BCG instillation, and a muscle-invasive form (stage ≥ T2), for which the treatment of choice is irradiation or cystectomy.The aim of the research underlying this thesis was to explore the factors involved in tumor development and progression, and to find prognostic markers for recurrence and progression in patients with primary stage T1 urothelial carcinoma of the bladder (UCB).Tumor tissue in archived paraffin blocks from patients diagnosed with that type of malignancy was used in the four studies that were conducted. This was a population-based project, because all of the patients had been reported to the cancer center in the Southeast Healthcare Region in Sweden from 1992 to 2001. The follow-up time was comparable long in the cases included and was intended to be at least 10 years.The hospital records were reviewed to gather information on clinical characteristics of the tumors, such as size and multiplicity, as well as treatment modalities, recurrence and/or progression, and eventual death from UBC. The original tumor slides were re-evaluated. These two initial activities yielded a study population comprising 211 well-characterized patients with primary T1 UCB. Some of the originally selected patients were excluded due to missing paraffin blocks or poor quality of the tumor material, the latter being particularly important in the genetic analyses conducted in the fourth study.Ordinary light microscopy was performed to evaluate specific tumor characteristics, such as lymphovascular tumor infiltration, and for T1 sub-staging. Immunohistochemistry was carried out to, among other things, analyze cell cycle regulators. Furthermore, pyrosequencing, single-strand conformation analysis (SSCA), and Sanger sequencing were conducted in the fourth study to assess mutations in the p53 gene and murine double minute 2 SNP309 promoter polymorphism. Statistical analyses to estimate the risk of tumor recurrence and progression were carried out in all four investigations.Conclusions: This population-based cohort of patients with well-characterized T1 tumors of the urinary bladder showed high rates of recurrence (80%) and progression (39%), and the aggressiveness is underlined by the fact that 32% died from the disease. Lymphovascular tumor infiltration and abnormal immunohistochemical staining for p16 were found to be associated with tumor progression, and in the future analysis of these parameters might be used in treatment decisions regarding T1 bladder tumors. No other clinical or pathological variable or cell cycle regulator was associated with progression, and none of the genetic analyses conducted in the current studies were helpful in predicting outcome or explaining the mechanisms of tumor development.
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