Semantic Fluency in Mild and Moderate Alzheimer's Disease

Alzheimer's disease (AD) is characterized by an impairment of the semantic memory responsible for processing meaning-related knowledge. This study was aimed at examining how Finnish-speaking healthy elderly subjects (n = 30) and mildly (n=20) and moderately (n = 20) demented AD patients utilize semantic knowledge to performa semantic fluency task, a method of studying semantic memory. In this task subjects are typically given 60 seconds to generate words belonging to the semantic category of animals. Successful task performance requires fast retrieval of subcategory exemplars in clusters (e.g., farm animals: 'cow', 'horse', 'sheep') and switching between subcategories (e.g., pets, water animals, birds, rodents). In this study, thescope of the task was extended to cover various noun and verb categories. The results indicated that, compared with normal controls, both mildly and moderately demented AD patients showed reduced word production, limited clustering and switching, narrowed semantic space, and an increase in errors, particularly perseverations. However, the size of the clusters, the proportion of clustered words, and the frequency and prototypicality of words remained relatively similar across the subject groups. Although the moderately demented patients showed a poor eroverall performance than the mildly demented patients in the individual categories, the error analysis appeared unaffected by the severity of AD. The results indicate a semantically rather coherent performance but less specific, effective, and flexible functioning of the semantic memory in mild and moderate AD patients. The findings are discussed in relation to recent theories of word production and semantic representation. Keywords: semantic fluency, clustering, switching, semantic category, nouns, verbs, Alzheimer's disease

Adenoviral gene therapy for non-small cell lung cancer

Adenoviral gene therapy is an experimental approach to cancer refractory to standard cancer therapies. Adenoviruses can be utilized as vectors to deliver therapeutic transgenes into cancer cells, while gene therapy with oncolytic adenoviruses exploits the lytic potential of viruses to kill tumor cells. Although adenoviruses demonstrate several advantages over other vectors - such as the unparalleled transduction efficacy and natural tropism to a wide range of tissues - the gene transfer efficacy to cancer cells has been limited, consequently restricting the therapeutic effect. There are, however, several approaches to circumvent this problem. We utilized different modified adenoviruses to obtain information on adenovirus tropism towards non-small cell lung cancer (NSCLC) cells. To enhance therapeutic outcome, oncolytic adenoviruses were evaluated. Further, to enhance gene delivery to tumors, we used mesenchymal stem cells (MSCs) as carriers. To improve adenovirus specificity, we investigated whether widely used cyclooxygenase 2 (Cox-2) promoter is induced by adenovirus infection in nontarget cells and whether selectivity can be retained by the 3 untranslated region (UTR) AU-rich elements. In addition, we investigated whether switching adenovirus fiber can retain gene delivery in the presence of neutralizing antibodies. Our results show that adenoviruses, whose capsids were modified with arginine-glycine-aspartatic acid (RGD-4C), the serotype 3 knob, or polylysins displayed enhanced gene transfer into NSCLC cell lines and fresh clinical specimens from patients. The therapeutic efficacy was further improved by using respective oncolytic adenoviruses with isogenic 24bp deletion in the E1A gene. Cox-2 promoter was also shown to be induced in normal and tumor cells following adenovirus infection, but utilization of 3 UTR elements can increase the tumor specificity of the promoter. Further, the results suggested that use of MSCs could enhance the bioavailability and delivery of adenoviruses into human tumors, although cells had no tumor tropism per se. Finally, we demonstrated that changing adenovirus fiber can allow virus to escape from existing neutralizing antibodies when delivered systemically. In conclusion, these results reveal that adenovirus gene transfer and specificity can be increased by using modified adenoviruses and MSCs as carriers, and fiber modifications simultaneously decrease the effect of neutralizing antibodies. This promising data suggest that these approaches could translate into clinical testing in patients with NSCLC refractory to current modalities.

Plant species diversity of buffer zones in agricultural landscapes: in search of determinants from the local to regional scale

Buffer zones are vegetated strip-edges of agricultural fields along watercourses. As linear habitats in agricultural ecosystems, buffer strips dominate and play a leading ecological role in many areas. This thesis focuses on the plant species diversity of the buffer zones in a Finnish agricultural landscape. The main objective of the present study is to identify the determinants of floral species diversity in arable buffer zones from local to regional levels. This study was conducted in a watershed area of a farmland landscape of southern Finland. The study area, Lepsämänjoki, is situated in the Nurmijärvi commune 30 km to the north of Helsinki, Finland. The biotope mosaics were mapped in GIS. A total of 59 buffer zones were surveyed, of which 29 buffer strips surveyed were also sampled by plot. Firstly, two diversity components (species richness and evenness) were investigated to determine whether the relationship between the two is equal and predictable. I found no correlation between species richness and evenness. The relationship between richness and evenness is unpredictable in a small-scale human-shaped ecosystem. Ordination and correlation analyses show that richness and evenness may result from different ecological processes, and thus should be considered separately. Species richness correlated negatively with phosphorus content, and species evenness correlated negatively with the ratio of organic carbon to total nitrogen in soil. The lack of a consistent pattern in the relationship between these two components may be due to site-specific variation in resource utilization by plant species. Within-habitat configuration (width, length, and area) were investigated to determine which is more effective for predicting species richness. More species per unit area increment could be obtained from widening the buffer strip than from lengthening it. The width of the strips is an effective determinant of plant species richness. The increase in species diversity with an increase in the width of buffer strips may be due to cross-sectional habitat gradients within the linear patches. This result can serve as a reference for policy makers, and has application value in agricultural management. In the framework of metacommunity theory, I found that both mass effect(connectivity) and species sorting (resource heterogeneity) were likely to explain species composition and diversity on a local and regional scale. The local and regional processes were interactively dominated by the degree to which dispersal perturbs local communities. In the lowly and intermediately connected regions, species sorting was of primary importance to explain species diversity, while the mass effect surpassed species sorting in the highly connected region. Increasing connectivity in communities containing high habitat heterogeneity can lead to the homogenization of local communities, and consequently, to lower regional diversity, while local species richness was unrelated to the habitat connectivity. Of all species found, Anthriscus sylvestris, Phalaris arundinacea, and Phleum pretense significantly responded to connectivity, and showed high abundance in the highly connected region. We suggest that these species may play a role in switching the force from local resources to regional connectivity shaping the community structure. On the landscape context level, the different responses of local species richness and evenness to landscape context were investigated. Seven landscape structural parameters served to indicate landscape context on five scales. On all scales but the smallest scales, the Shannon-Wiener diversity of land covers (H') correlated positively with the local richness. The factor (H') showed the highest correlation coefficients in species richness on the second largest scale. The edge density of arable field was the only predictor that correlated with species evenness on all scales, which showed the highest predictive power on the second smallest scale. The different predictive power of the factors on different scales showed a scaledependent relationship between the landscape context and local plant species diversity, and indicated that different ecological processes determine species richness and evenness. The local richness of species depends on a regional process on large scales, which may relate to the regional species pool, while species evenness depends on a fine- or coarse-grained farming system, which may relate to the patch quality of the habitats of field edges near the buffer strips. My results suggested some guidelines of species diversity conservation in the agricultural ecosystem. To maintain a high level of species diversity in the strips, a high level of phosphorus in strip soil should be avoided. Widening the strips is the most effective mean to improve species richness. Habitat connectivity is not always favorable to species diversity because increasing connectivity in communities containing high habitat heterogeneity can lead to the homogenization of local communities (beta diversity) and, consequently, to lower regional diversity. Overall, a synthesis of local and regional factors emerged as the model that best explain variations in plant species diversity. The studies also suggest that the effects of determinants on species diversity have a complex relationship with scale.

Biochemical and structural properties of Potato virus A VPg

The potato virus A (PVA) genome linked protein (VPg) is a multifunctional protein that takes part in vital infection cycle events such as replication and movement of the virus from cell to cell. VPg is attached to the 5´ end of the genome and is carried in the tip structure of the filamentous virus particle. VPg is also the last protein to be cleaved from the polyprotein. VPg interacts with several viral and host proteins and is phosphorylated at several positions. These features indicate a central role in virus epidemiology and a requirement for an efficient but flexible mechanism for switching between different functions. -- This study examines some of the key VPg functions in more detail. Mutations in the positively charged region from Ala38 to Lys44 affected the NTP binding, uridylylation, and in vitro translation inhibition activities of VPg, whereas in vivo translation inhibition was not affected. Some of the data generated in this study implicated the structural flexibility of the protein in functional activities. VPg lacks a rigid structure, which could allow it to adapt conformationally to different functions as needed. A major finding of this study is that PVA VPg belongs to the class of ´intrinsically disordered proteins´ (IDPs). IDPs are a novel protein class that has helped to explain the observed lack of structure. The existence of IDPs clearly shows that proteins can be functional and adapt a native fold without a rigid structure. Evidence for the intrinsic disorder of VPg was provided by CD spectroscopy, NMR, fluorescence spectroscopy, bioinformatic analysis, and limited proteolytic digestion. The structure of VPg resembles that of a molten globule-type protein and has a hydrophobic core domain. Approximately 50% of the protein is disordered and an α-helical stabilization of these regions has been hypothesized. Surprisingly, VPg structure was stabilized in the presence of anionic lipid vesicles. The stabilization was accompanied by a change in VPg structure and major morphological modifications of the vesicles, including a pronounced increase in the size and appearance of pore or plaque like formations on the vesicle surface. The most likely scenario seems to be an α-helical stabilization of VPg which induces formation of a pore or channel-like structure on the vesicle surface. The size increase is probably due to fusion or swelling of the vesicles. The latter hypothesis is supported by the evident disruption of the vesicles after prolonged incubation with VPg. A model describing the results is presented and discussed in relation to other known properties of the protein.

Determinants of farmer retirement and farm succession in Finland

In the past decade, the Finnish agricultural sector has undergone rapid structural changes. The number of farms has decreased and the average farm size has increased when the number of farms transferred to new entrants has decreased. Part of the structural change in agriculture is manifested in early retirement programmes. In studying farmers exit behaviour in different countries, institutional differences, incentive programmes and constraints are found to matter. In Finland, farmers early retirement programmes were first introduced in 1974 and, during the last ten years, they have been carried out within the European Union framework for these programmes. The early retirement benefits are farmer specific and de-pend on the level of pension insurance the farmer has paid over his active farming years. In order to predict the future development of the agricultural sector, farmers have been frequently asked about their future plans and their plans for succession. However, the plans the farmers made for succession have been found to be time inconsistent. This study estimates the value of farmers stated succession plans in predicting revealed succession decisions. A stated succession plan exists when a farmer answers in a survey questionnaire that the farm is going to be transferred to a new entrant within a five-year period. The succession is revealed when the farm is transferred to a suc-cessor. Stated and revealed behaviour was estimated as a recursive Binomial Probit Model, which accounts for the censoring of the decision variables and controls for a potential correlation between the two equations. The results suggest that the succession plans, as stated by elderly farmers in the questionnaires, do not provide information that is significant and valuable in predicting true, com-pleted successions. Therefore, farmer exit should be analysed based on observed behaviour rather than on stated plans and intentions. As farm retirement plays a crucial role in determining the characteristics of structural change in agriculture, it is important to establish the factors which determine an exit from farming among eld-erly farmers and how off-farm income and income losses affect their exit choices. In this study, the observed choice of pension scheme by elderly farmers was analysed by a bivariate probit model. Despite some variations in significance and the effects of each factor, the ages of the farmer and spouse, the age and number of potential successors, farm size, income loss when retiring and the location of the farm together with the production line were found to be the most important determi-nants of early retirement and the transfer or closure of farms. Recently, the labour status of the spouse has been found to contribute significantly to individual retirement decisions. In this study, the effect of spousal retirement and economic incentives related to the timing of a farming couple s early retirement decision were analysed with a duration model. The results suggest that an expected pension in particular advances farm transfers. It was found that on farms operated by a couple, both early retirement and farm succession took place more often than on farms operated by a single person. However, the existence of a spouse delayed the timing of early retirement. Farming couples were found to co-ordinate their early retirement decisions when they both exit through agricultural retirement programmes, but such a co-ordination did not exist when one of the spouses retired under other pension schemes. Besides changes in the agricultural structure, the share and amount of off-farm income of a farm family s total income has also increased. In the study, the effect of off-farm income on farmers retirement decisions, in addition to other financial factors, was analysed. The unknown parameters were first estimated by a switching-type multivariate probit model and then by the simulated maxi-mum likelihood (SML) method, controlling for farmer specific fixed effects and serial correlation of the errors. The results suggest that elderly farmers off-farm income is a significant determinant in a farmer s choice to exit and close down the farm. However, off-farm income only has a short term effect on structural changes in agriculture since it does not significantly contribute to the timing of farm successions.

Genetics of T cell co-stimulatory receptors -CD28, CTLA4, ICOS and PDCD1 in immunity and transplantation

Co-stimulatory signals are essential for the activation of naïve T cells and productive immune response. Naïve T cells receive first, antigen-specific signal through T cell receptor. Co-stimulatory receptors provide the second signal which can be either activating or inhibitory. The balance between signals determines the outcome of an immune response. CD28 is crucial for T cell activation; whereas cytotoxic T lymphocyte associated antigen 4 (CTLA4) mediates critical inhibitory signal. Inducible co-stimulator (ICOS) augments cytokine expression and plays role in immunoglobulin class switching. Programmed cell death 1 (PDCD1) acts as negative regulator of T cell proliferation and cytokine responses. The co-stimulatory receptor pathways are potentially involved in self-tolerance and thus, they provide a promising therapeutic strategy for autoimmune diseases and transplantation. The genes encoding CD28, CTLA4 and ICOS are located adjacently in the chromosome region 2q33. The PDCD1 gene maps further, to the region 2q37. CTLA4 and PDCD1 are associated with the risk of a few autoimmune diseases. There is strong linkage disequilibrium (LD) on the 2q33 region; the whole gene of CD28 exists in its own LD block but CTLA4 and the 5' part of ICOS are within a same LD block. The 3' part of ICOS and PDCD1 are in their own separate LD blocks. Extended haplotypes covering the 2q33 region can be identified. This study focuses on immune related conditions like coeliac disease (CD) which is a chronic inflammatory disease with autoimmune features. Immunoglobulin A deficiency (IgAD) belongs to the group of primary antibody deficiencies characterised by reduced levels of immunoglobulins. IgAD co-occurs often with coeliac disease. Renal transplantation is needed in the end stage kidney diseases. Transplantation causes strong immune response which is tried to suppress with drugs. All these conditions are multifactorial with complex genetic background and multiple environmental factors affecting the outcome. We have screened ICOS for polymorphisms by sequencing the exon regions. We detected 11 new variants and determined their frequencies in Finnish population. We have measured linkage disequilibrium on the 2q33 region in Finnish as well as other European populations and observed conserved haplotypes. We analysed genetic association and linkage of the co-stimulatory receptor gene region aiming to study if it is a common risk locus for immune diseases. The 2q33 region was replicated to be linked to coeliac disease in Finnish population and CTLA4-ICOS haplotypes were found to be associated with CD and IgAD being the first non-HLA risk locus common for CD and immunodeficiencies. We also showed association between ICOS and the outcome of kidney transplantation. Our results suggest new evidence for CTLA4-ICOS gene region to be involved in susceptibility of coeliac disease. The earlier published contradictory association results can be explained by involvement of both CTLA4 and ICOS in disease susceptibility. The pattern of variants acting together rather than a single polymorphism may confer the disease risk. These genes may predispose also to immunodeficiencies as well as decreased graft survival and delayed graft function. Consequently, the present study indicates that like the well established HLA locus, the co-stimulatory receptor genes predispose to variety of immune disorders.

Health-Related Quality of Life, Costs and Treatment of Inflammatory Rheumatic Diseases in Routine Practice : With special emphasis on biological drugs

Rheumatoid arthritis (RA) and other chronic inflammatory joint diseases already begin to affect patients health-related quality of life (HRQoL) in the earliest phases of these diseases. In treatment of inflammatory joint diseases, the last two decades have seen new strategies and treatment options introduced. Treatment is started at an earlier phase; combinations of disease-modifying anti-rheumatic drugs (DMARDs) and corticosteroids are used; and in refractory cases new drugs such as tumour necrosis factor (TNF) inhibitors or other biologicals can be started. In patients with new referrals to the Department of Rheumatology of the Helsinki University Central Hospital, we evaluated the 15D and the Stanford Health Assessment Questionnaire (HAQ) results at baseline and approximately 8 months after their first visit. Altogether the analysis included 295 patients with various rheumatic diseases. The mean baseline 15D score (0.822, SD 0.114) was significantly lower than for the age-matched general population (0.903, SD 0.098). Patients with osteoarthritis (OA) and spondyloarthropathies (SPA) reported the poorest HRQoL. In patients with RA and reactive arthritis (ReA) the HRQoL improved in a statistically significant manner during the 8-month follow-up. In addition, a clinically important change appeared in patients with systemic rheumatic diseases. HAQ score improved significantly in patients with RA, arthralgia and fibromyalgia, and ReA. In a study of 97 RA patients treated either with etanercept or adalimumab, we assessed their HRQoL with the RAND 36-Item Health Survey 1.0 (RAND-36) questionnaire. We also analysed changes in clinical parameters and the HAQ. With etanercept and adalimumab, the values of all domains in the RAND-36 questionnaire increased during the first 3 months. The efficacy of each in improving HRQoL was statistically significant, and the drug effects were comparable. Compared to Finnish age- and sex-matched general population values, the HRQoL of the RA patients was significantly lower at baseline and, despite the improvement, remained lower also at follow-up. Our RA patients had long-standing and severe disease that can explain the low HRQoL also at follow-up. In a pharmacoeconomic study of patients treated with infliximab we evaluated medical and work disability costs for patients with chronic inflammatory joint disease during one year before and one year after institution of infliximab treatment. Clinical and economic data for 96 patients with different arthritis diagnoses showed, in all patients, significantly improved clinical and laboratory variables. However, the medical costs increased significantly during the second period by 12 015 (95% confidence interval, 6 496 to 18 076). Only a minimal decrease in work disability costs occurred mean decrease 130 (-1 268 to 1 072). In a study involving a switch from infliximab to etanercept, we investigated the clinical outcome in 49 patients with RA. Reasons for switching were in 42% failure to respond by American College of Rheumatology (ACR) 50% criteria; in 12% adverse event; and in 46% non-medical reasons although the patients had responded to infliximab. The Disease Activity Score with 28 joints examined (DAS28) allowed us to measure patients disease activity and compare outcome between groups based on the reason for switching. In the patients in whom infliximab was switched to etanercept for nonmedical reasons, etanercept continued to suppress disease activity effectively, and 1-year drug survival for etanercept was 77% (95% CI, 62 to 97). In patients in the infliximab failure and adverse event groups, DAS28 values improved significantly during etanercept therapy. However, the 1-year drug survival of etanercept was only 43% (95% CI, 26 to 70) and 50% (95% CI, 33 to 100), respectively. Although the HRQoL of patients with inflammatory joint diseases is significantly lower than that of the general population, use of early and aggressive treatment strategies including TNF-inhibitors can improve patients HRQoL effectively. Further research is needed in finding new treatment strategies for those patients who fail to respond or lose their response to TNF-inhibitors.

Anti-TNF treatment in juvenile idiopathic arthritis and associated uveitis : Clinical perspectives on growth, uveitis, and drug survival

Juvenile idiopathic arthritis (JIA) is a heterogeneous group of childhood chronic arthritides, associated with chronic uveitis in 20% of cases. For JIA patients responding inadequately to conventional disease-modifying anti-rheumatic drugs (DMARDs), biologic therapies, anti-tumor necrosis factor (anti-TNF) agents are available. In this retrospective multicenter study, 258 JIA-patients refractory to DMARDs and receiving biologic agents during 1999-2007 were included. Prior to initiation of anti-TNFs, growth velocity of 71 patients was delayed in 75% and normal in 25%. Those with delayed growth demonstrated a significant increase in growth velocity after initiation of anti-TNFs. Increase in growth rate was unrelated to pubertal growth spurt. No change was observed in skeletal maturation before and after anti-TNFs. The strongest predictor of change in growth velocity was growth rate prior to anti-TNFs. Change in inflammatory activity remained a significant predictor even after decrease in glucocorticoids was taken into account. In JIA-associated uveitis, impact of two first-line biologic agents, etanercept and infliximab, and second-line or third-line anti-TNF agent, adalimumab, was evaluated. In 108 refractory JIA patients receiving etanercept or infliximab, uveitis occurred in 45 (42%). Uveitis improved in 14 (31%), no change was observed in 14 (31%), and in 17 (38%) uveitis worsened. Uveitis improved more frequently (p=0.047) and frequency of annual uveitis flares was lower (p=0.015) in those on infliximab than in those on etanercept. In 20 patients taking adalimumab, 19 (95%) had previously failed etanercept and/or infliximab. In 7 patients (35%) uveitis improved, in one (5%) worsened, and in 12 (60%) no change occurred. Those with improved uveitis were younger and had shorter disease duration. Serious adverse events (AEs) or side-effects were not observed. Adalimumab was effective also in arthritis. Long-term drug survival (i.e. continuation rate on drug) with etanercept (n=105) vs. infliximab (n=104) was at 24 months 68% vs. 68%, and at 48 months 61% vs. 48% (p=0.194 in log-rank analysis). First-line anti-TNF agent was discontinued either due to inefficacy (etanercept 28% vs. infliximab 20%, p=0.445), AEs (7% vs. 22%, p=0.002), or inactive disease (10% vs. 16%, p=0.068). Females, patients with systemic JIA (sJIA), and those taking infliximab as the first therapy were at higher risk for treatment discontinuation. One-third switched to the second anti-TNF agent, which was discontinued less often than the first. In conclusion, in refractory JIA anti-TNFs induced enhanced growth velocity. Four-year treatment survival was comparable between etanercept and infliximab, and switching from first-line to second-line agent a reasonable therapeutic option. During anti-TNF treatment, one-third with JIA-associated anterior uveitis improved.