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- Baecklund, Eva, 1956-
(författare)
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Associations Between Rheumatoid Arthritis and Malignant Lymphomas
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Patients with rheumatoid arthritis (RA) are at increased risk of developing malignant lymphoma, although details about this association remain unclear. The aims of this thesis were to investigate risk factors for lymphoma in patients with RA and to characterize these lymphomas regarding subtype, presence of Epstein-Barr virus (EBV), clinical manifestations and prognosis.The Swedish hospital discharge register and the cancer register were used to identify RA patients with lymphoma. Two case-control studies were performed, one smaller including RA patients with lymphoma hospitalised in Uppsala health care region 1964-1983 (n=41) and one larger study of hospitalised RA patients with lymphoma in Sweden 1964-1995 (n=378). RA patients from the same cohorts, but without lymphoma, were matched as controls. Medical records for cases and controls were scrutinized for exposure information. The lymphoma tissues were reclassified according to the WHO classification, and presence of EBV was analysed by EBER in situ hybridisation.The most important risk factor for lymphoma development was high RA disease activity. No association was determined between treatment with traditional disease modifying drugs, non-steroidal anti-inflammatory drugs, aspirin, peroral and intra-articular corticosteroids and lymphoma risk. Diffuse large B-cell lymphoma (DLBCL) was more frequent in RA patients than in lymphoma patients in the general population and displayed stronger association with RA disease activity than other lymphoma subtypes. RA patients with DLBCL had increased extranodal involvement and more advanced lymphoma stage at presentation than DLBCL patients in general, and the prognosis was poor.A further subdivision of DLBCL into germinal centre (GC) and non-GC subtypes by the expression patterns of CD10, bcl-6 and IRF-4 showed a predominance of the non-GC subtype. This suggested peripheral activated B-cells as the cells of origin in these lymphomas.The presence of EBV was low in lymphomas in RA patients (12%).
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| 2. |
- Ekbom, Anders, 1963
(författare)
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Economic Analysis of Soil Capital, Land Use and Agricultural Production in Kenya
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The purpose of this thesis is to investigate economic and natural science aspects of soil management and agricultural production in a developing country context. It does so by theoretical as well as empirical investigation, based on data from field surveys in Kenya’s central highlands over several years. The rationale for the thesis is the need to increase our understanding of the economics of soil capital, land use and agricultural production in order to design policies promoting sustainable development. The thesis includes papers on: optimal soil use with downstream externalities (Ch. 2); determinants of soil capital and agricultural production (Ch. 3; 4); links between farmers’ resource levels, soil properties and agricultural productivity (Ch. 5); and land use-change and determinants of rural-urban migration in Kenya (Ch. 6). Chapter 2 shows that farmers may need incentives (taxes, subsidies or charges) to induce them to reduce soil erosion and thereby downstream damages. Furthermore we find other factors (low discount rate, tenure security, access to credits, crop insurance) that promote accumulation of soil capital and reduce soil loss and nutrient leakage. Regression analyses in Chapter 3 show that farmers’ soil capital is not a given or fixed factor but depends on soil conservation investments, and the allocation of labour, crops, manure and fertilizer in agricultural production. The wide distribution of soil properties across farms indicates the need to tailor technical extension advice to farmers’ preferences and the farm-specific economic and agro-ecological circumstances, and enhance the use of integrated soil analysis, field assessment and detailed soil mapping at farm level. Regressions in Chapter 4 show that agricultural output is determined not only by farmers’ input of land, labour, manure and fertilizer, but also by the quality of soil conservation investments and farm-specific soil properties. Hence, integrating economics and soil science is highly worthwhile in this research area. Omitting soil capital measures can cause omitted variables bias since farmers’ choice of inputs depend both on the quality and status of the soil capital and on other economic conditions (e.g. availability and cost of labour, fertilizers and other inputs). Chapter 5 shows that: relatively richer farmers have higher crop yields; poorer farmers have lower soil nutrient levels; farms with gentle slope and high resource level have the highest land management rating. These results indicate that actions aimed at promoting higher yields and sustainable agriculture will have to differ depending on farmers’ endowment, and that agricultural policy advice needs to be adapted to farmers’ resource levels. Chapter 6 shows that farmers have changed their farming system considerably during the last 40 years: introduced new (cash) crops, increased tree cover, reduced terracing, diversified crops and income sources, and increased market orientation and temporary work in cities. The study emphasizes the need to improve extension advice, rural roads, supply of inputs, local ownership of public soil conservation investment programs, access to credits and output markets, and job opportunities for farmers during agricultural off-season e.g. work in local food processing industries.
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| 4. |
- Elfström, Peter, 1974-
(författare)
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Associated disorders in celiac disease
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Celiac disease (CD) is an autoimmune disorder that affects genetically susceptible individuals and is induced by dietary gluten. Treatment consists of a lifelong gluten-free diet. CD is common and affects about 1% of the general population. The classic symptoms include diarrhea and malabsorption, but many patients have only mild symptoms or no symptoms at all. The proportion of individuals presenting with atypical symptoms or discovered only when investigating an associated condition of CD is increasing. Aims: The aim of this thesis was to investigate the risk of possible associated disorders through Swedish population-based registers. The objective was to gain more information on the consequences of having CD and to identify high risk groups where screening may be considered. Materials and methods: We used the Swedish hospital discharge register to examine the risk of liver disease, autoimmune heart disease, Addison’s disease and thyroid disorders in a cohort of about 14,000 individuals with CD and an age and sex matched reference population of 70,000 individuals. In the last study we used all regional pathology registers and the cancer registry to examine the risk of hematopoietic cancer, including lymphoma in three different cohorts: I) 28,810 individuals with CD; II) 12,681 individuals with small intestinal mucosal inflammation but without villous atrophy; and III) 3552 individuals with latent CD (a positive serology test for CD with a normal small intestinal biopsy). Results: CD is statistically significantly associated with an increased risk of liver disease, Addison’s disease, thyroid disease and lymphoma. We also found an increased risk of lymphoma in individuals with small intestinal mucosal inflammation. There was no statistically significant association between autoimmune heart disease or leukemia and CD. Latent CD was not associated with any hematopoietic cancers. Conclusion: This thesis found a positive association between CD and a number of autoimmune and inflammatory disorders. Clinicians need to have a high awareness of this association and to test for these conditions when symptoms appear.
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| 5. |
- Knight, Ann, 1957-
(författare)
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Clinical and Epidemiological Studies of Wegener´s Granulomatosis
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Wegener´s granulomatosis (WG) is an unusual, serious, systemic vasculitis with specific clinical findings. The studies in this thesis aim at broadening our understanding of the aetiology and outcome of WG.Patients with WG were identified in the In-patient Register 1975-2001. During this time the incidence increased three-fold, and neither ANCA-related increased awareness, nor diagnostic drift, seem to fully explain this trend, but it is still unclear if a true rise in incidence exists.Anti- neutrophil cytoplasmic antibodies (ANCA) have been presented as highly specific for vasculitis. In a series of consecutive cANCA/PR3-ANCA positive patients, we investigated the positive predictive value for ANCA, and the outcome of patients with a positive cANCA/PR3-ANCA but not vasculitis. These patients have a low future risk of developing vasculitis, possibly indicating that ANCA, in this setting, reflects neutrophil activating properties not specific to vasculitis.By linkage of the WG-cohort, and randomly selected population controls, to the Multi-generation register, we identified all first-degree relatives and spouses of patients and controls, totally encompassing some 2,000 patients and 70,000 relatives. Familial aggregation of WG was the exception, with absolute risks of < 1 per 1000.However, relative risks in first-grade relatives amounted to 1.56 (95% CI 0.35-6.90) such that a moderate familial aggregation cannot be excluded.In the WG-cohort, cancer occurrence and risk was compared to that of the general population. Patients with WG have an overall doubled risk of cancer, with particularly increased risks of bladder-cancer, haematopoietic cancers including lymphomas and squamous skin-cancer. In a case-control study nested within the WG-cohort, treatment with cyclophosphamide was compared among bladder-cancer patients and matched cancer-free controls. Absolute risk of bladder cancer as high as 10% some years after diagnosis were found, and this risk can partly be attributed to cyclophosphamide-treatment, with a dose-response relationship.
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| 6. |
- Ludvigsson, Jonas F.
(författare)
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Some epidemiological aspects of perinatal gastrointestinal disease
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- [Respondenten]Hör upp alla männ'skor t trakten.Ni är bjudna att delta i spikningsakten.Nu vill jag er informeraoch min avhandling summera.Sex studier av skilda slag,en restumé i form av vers, inget föredrag.Studie ett till fem bygger på barn i tusental,cirka tio, födda nittisju, nittiåtta eller nittnio.(Förutsatt förstås att deras mor har haft sitt härbärge,Någonstans uti sydöstra Sverige.)Låt oss gå från helhet till detalj,och följa en genomsnittsfamilj, en ömsint kvmna och en kanalj.Akt I Förlossningssalen.[Barnet] Efter graviditeten fyrti veckor långbörjar jordelivet efter passage så fasligt trång.Där står pappa glad och lermot mor och mig, [Far] -Åh, vad jag älskar er![Far] Men nu kära mor är det dags att fylla i enkäten(!),hur du har haft det under "graviditäten".Har du och jag nå'n sjukdom, kanske "gluten"?(undrar barnets far, den långe drasuten)(Mor] Gluten, nu har jag änligen fått klämpå varför vårt barn vägde mindre än "två och fem"!Även om du varit noga med aptiten,är det nog tarminflammationen din som gjort'en liten![Far] (Pekar på mor) En annan orsak kan vara böldema dina l tarme,[Mor] liten av ulcerös koliten, å gud forbarme![Far] och säger far, att sonen fötts för tidigt, var det gastroenteriten?Du Vet i fjärde måna'n hade du problem med "skiten"![Mor] Men sonen var blott tidig med en enda da'?![Far] Men det var ju det han Ludvigsson sa!Akt II Förlossningssalen. Barnmorska gör entré.[Barnmorska] Ligg ner kära mor, ni är blek som ett lärft!Det är även barnet, kan det vara något han ärvt? (Väntar inte på svar, vänder sig till mor)Att ha ont, att må illa är snarast kutym.[Mor] Tack jag mår bra men hur är det med antikroppsmängd mot transglutaminas-enzym?[Barnmorska] Det är svårt att säga, men den kanske växlar under loppet av ett år, jag tror Ludvigsson fått upp ett spår![Respondenten]Då lämnar vi patient, barn, far och barnmorskeintendenten.Det var allt för denna gång från den unge respondenten.
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