On the moderators of trait avoidance motivation in predicting cognitive biases and adjustment

The present research focused on motivational and personality traits measuring individual differences in the experience of negative affect, in reactivity to negative events, and in the tendency to avoid threats. In this thesis, such traits (i.e., neuroticism and dispositional avoidance motivation) are jointly referred to as trait avoidance motivation. The seven studies presented here examined the moderators of such traits in predicting risk judgments, negatively biased processing, and adjustment. Given that trait avoidance motivation encompasses reactivity to negative events and tendency to avoid threats, it can be considered surprising that this trait does not seem to be related to risk judgments and that it seems to be inconsistently related to negatively biased information processing. Previous work thus suggests that some variable(s) moderate these relations. Furthermore, recent research has suggested that despite the close connection between trait avoidance motivation and (mal)adjustment, measures of cognitive performance may moderate this connection. However, it is unclear whether this moderation is due to different response processes between individuals with different cognitive tendencies or abilities, or to the genuinely buffering effect of high cognitive ability against the negative consequences of high trait avoidance motivation. Studies 1-3 showed that there is a modest direct relation between trait avoidance motivation and risk judgments, but studies 2-3 demonstrated that state motivation moderates this relation. In particular, individuals in an avoidance state made high risk judgments regardless of their level of trait avoidance motivation. This result explained the disparity between the theoretical conceptualization of avoidance motivation and the results of previous studies suggesting that the relation between trait avoidance motivation and risk judgments is weak or nonexistent. Studies 5-6 examined threat identification tendency as a moderator for the relationship between trait avoidance motivation and negatively biased processing. However, no evidence for such moderation was found. Furthermore, in line with previous work, the results of studies 5-6 suggested that trait avoidance motivation is inconsistently related to negatively biased processing, implying that theories concerning traits and information processing may need refining. Study 7 examined cognitive ability as a moderator for the relation between trait avoidance motivation and adjustment, and demonstrated that cognitive ability moderates the relation between trait avoidance motivation and indicators of both self-reported and objectively measured adjustment. Thus, the results of Study 7 supported the buffer explanation for the moderating influence of cognitive performance. To summarize, the results showed that it is possible to find factors that consistently moderate the relations between traits and important outcomes (e.g. adjustment). Identifying such factors and studying their interplay with traits is one of the most important goals of current personality research. The present thesis contributed to this line of work in relation to trait avoidance motivation.

Fibroblast nemosis in malignant progression of epithelial cells

Paracrine regulation between the components of the tumour microenvironment cancer cells, activated fibroblasts, immune and endothelial cells is under intense investigation. The signals between the different cell types are mediated by soluble factors, such as growth factors, proinflammatory cytokines and proteolytic enzymes. Nemosis is an experimental in vitro model of fibroblast activation, leading to increased production of such mediators. Nemotic activation of fibroblasts occurs as they are forced to cluster thereby forming a multicellular spheroid. The aim of the present studies was to elucidate the mechanisms underlying the nemotic response of cancer-associated fibroblasts (CAF) and the role of nemosis in paracrine regulation between activated fibroblasts and benign and malignant epithelial cells. The results presented in this thesis demonstrate that the nemotic response of CAFs and normal fibroblasts differs, and inter-individual variations exist between fibroblast populations. In co-culture experiments, fibroblasts increased colony formation of squamous cell carcinoma (SCC) cells, and CAFs further augmented this, highlighting the tumour-evolving properties of CAFs. Furthermore, fibroblast monolayers in those co-cultures started to cluster spontaneously. This kind of spontaneous nemosis response might take place also in vivo, although more direct evidence of this still needs to be obtained. The HaCaT skin carcinoma progression model was used to study the effects of benign and malignant keratinocytes on fibroblast nemosis. Benign HaCaT cells inhibited fibroblast nemosis, observed as inhibition of cyclooxygenase 2 (COX-2) induction in nemotic spheroids. In contrast, malignant HaCaTs further augmented the nemotic response by increasing expression of COX-2 and the growth factors hepatocyte growth factor / scatter factor (HGF/SF) and vascular endothelial growth factor (VEGF), as well as causing a myofibroblastic differentiation of nemotic fibroblasts into fibroblasts resembling CAFs. On the other side of this reciprocal signalling, factors secreted into conditioned medium by the nemotic fibroblasts promoted proliferation and motility of the HaCaT cell lines. Notably, the nemotic fibroblast medium increased the expression of p63, a transcription factor linked to carcinogenesis, also in the highly metastatic HaCaT cells. These results emphasize the paracrine role of factors secreted by activated fibroblasts in driving tumour progression. We also investigated the epithelial-mesenchymal transition (EMT) of the HaCaT clones in response to transforming growth factor β (TGF-β), which is a well-characterized inducer of EMT. TGF-β caused growth arrest and loss of epithelial cell junctions in the HaCaT derivatives, but mesenchymal markers were not induced, suggesting a partial, but not complete EMT response. Inflammation induced by COX-2 has been proposed to be a key mechanism in EMT of benign cells. Corroborating this notion, COX-2 was induced only in benign, not in malignant HaCaT derivatives. Furthermore, in cells in which TGF-β caused COX-2 induction, migration was clearly augmented. The concept of treating cancer is changing from targeting solely the cancer cells to targeting the whole microenvironment. The results of this work emphasise the role of activated fibroblasts in cancer progression and that CAFs should also be taken into consideration in the treatment of cancer. The results from these studies suggests that nemosis could be used as a diagnostic tool to distinguish in vitro activated fibroblasts from tumour stroma and also in studying the paracrine signalling that is mediated to other cell types via soluble factors.

A Critical Evaluation of the MARS Treatment in Finland

The Molecular Adsorbent Recirculating System (MARS) is an extracorporeal albumin dialysis device which is used in the treatment of liver failure patients. This treatment was first utilized in Finland in 2001, and since then, over 200 patients have been treated. The aim of this thesis was to evaluate the impact of the MARS treatment on patient outcome, the clinical and biochemical variables, as well as on the psychological and economic aspects of the treatment in Finland. This thesis encompasses 195 MARS-treated patients (including patients with acute liver failure (ALF), acute-on-chronic liver failure (AOCLF) and graft failure), and a historical control group of 46 ALF patients who did not undergo MARS. All patients received a similar standard medical therapy at the same intensive care unit. The baseline data (demographics, laboratory and clinical variables) and MARS treatment-related and health-related quality-of-life data were recorded before and after treatment. The direct medical costs were determined for a period of 3.5 years.Additionally, the outcome of patients (survival, native liver recovery and need for liver transplantation) and survival predicting factors were investigated. In the outcome analysis, for the MARS-treated ALF patients, their 6-month survival (75% vs. 61%, P=0.07) and their native liver recovery rate (49% vs. 17%, P<0.001) were higher, and their need for transplantations was lower (29% vs. 57%, P= 0.001) than for the historical controls. However, the etiological distribution of the ALF patients referred to our unit has changed considerably over the past decade and the percentage of patients with a more favorable prognosis has increased. The etiology of liver failure was the most important predictor of the outcome. Other survival predicting factors in ALF included hepatic encephalopathy, the coagulation factors and the liver enzyme levels prior to MARS treatment. In terms of prognosis, the MARS treatment of the cirrhotic AOCLF patient seems meaningful only when the patient is eligible for transplantation. The MARS treatment appears to halt the progression of encephalopathy and reduce the blood concentration of neuroactive amino acids, albumin-bound and water-soluble toxins. In general, the effects of the MARS treatment seem to stabilize the patients, thus allowing additional time either for the native liver to recover, or for the patients to endure the prolonged waiting for transplantation. Furthermore, for the ALF patients, the MARS treatment appeared to be less costly and more cost-efficient than the standard medical therapy alone. In conclusion, the MARS treatment appears to have a beneficial effect on the patient outcome in ALF and in those AOCLF patients who can be bridged to transplantation.

Detection and progression of chronic allograft nephropathy : A study based on protocol biopsies

Background. Kidney transplantation (KTX) is considered to be the best treatment of terminal uremia. Despite improvements in short-term graft survival, a considerable number of kidney allografts are lost due to the premature death of patients with a functional kidney and to chronic allograft nephropathy (CAN). Aim. To investigate the risk factors involved in the progression of CAN and to analyze diagnostic methods for this entity. Materials and methods. Altogether, 153 implant and 364 protocol biopsies obtained between June 1996 and April 2008 were analyzed. The biopsies were classified according to Banff ’97 and chronic allograft damage index (CADI). Immunohistochemistry for TGF-β1 was performed in 49 biopsies. Kidney function was evaluated by creatinine and/or cystatin C measurement and by various estimates of glomerular filtration rate (GFR). Demographic data of the donors and recipients were recorded after 2 years’ follow-up. Results. Most of the 3-month biopsies (73%) were nearly normal. The mean CADI score in the 6-month biopsies decreased significantly after 2001. Diastolic hypertension correlated with ΔCADI. Serum creatinine concentration at hospital discharge and glomerulosclerosis were risk factors for ΔCADI. High total and LDL cholesterol, low HDL and hypertension correlated with chronic histological changes. The mean age of the donors increased from 41 -52 years. Older donors were more often women who had died from an underlying disease. The prevalence of delayed graft function increased over the years, while acute rejections (AR) decreased significantly over the years. Sub-clinical AR was observed in 4% and it did not affect long-term allograft function or CADI. Recipients´ drug treatment was modified along the Studies, being mycophenolate mophetil, tacrolimus, statins and blockers of the renine-angiotensin-system more frequently prescribed after 2001. Patients with a higher ΔCADI had lower GFR during follow-up. CADI over 2 was best predicted by creatinine, although with modest sensitivity and specificity. Neither cystatin C nor other estimates of GFR were superior to creatinine for CADI prediction. Cyclosporine A toxicity was seldom seen. Low cyclosporin A concentration after 2 h correlated with TGF- β1 expression in interstitial inflammatory cells, and this predicted worse graft function. Conclusions. The progression of CAN has been affected by two major factors: the donors’ characteristics and the recipients’ hypertension. The increased prevalence of DGF might be a consequence of the acceptance of older donors who had died from an underlying disease. Implant biopsies proved to be of prognostic value, and they are essential for comparison with subsequent biopsies. The progression of histological damage was associated with hypertension and dyslipidemia. The augmented expression of TGF-β1 in inflammatory cells is unclear, but it may be related to low immunosuppression. Serum creatinine is the most suitable tool for monitoring kidney allograft function on every-day basis. However, protocol biopsies at 6 and 12 months predicted late kidney allograft dysfunction and affected the clinical management of the patients. Protocol biopsies are thus a suitable surrogate to be used in clinical trials and for monitoring kidney allografts.

IgA nephropathy and Henoch-Schönlein nephritis in adults : with special reference to factors affecting outcome

IgA nephropathy (IgAN) is the most common primary glomerulonephritis. In one third of the patients the disease progresses, and they eventually need renal replacement therapy. IgAN is in most cases a slowly progressing disease, and the prediction of progression has been difficult, and the results of studies have been conflicting. Henoch-Schönlein nephritis (HSN) is rare in adults, and prediction of the outcome is even more difficult than in IgAN. This study was conducted to evaluate the clinical and histopathological features and predictors of the outcome of IgAN and HSN diagnosed in one centre (313 IgAN patients and 38 HSN patients), and especially in patients with normal renal function at the time of renal biopsy. The study also aimed to evaluate whether there is a difference in the progression rates in four countries (259 patients from Finland, 112 from UK, 121 from Australia and 274 from Canada), and if so, can this be explained by differences in renal biopsy policy. The third aim was to measure urinary excretions of cytokines interleukin 1ß (IL-1ß) and interleukin 1 receptor antagonist (IL-1ra) in patients with IgAN and HSN and the correlations of excretion of these substances with histopathological damage and clinical factors. A large proportion of the patients diagnosed in Helsinki as having IgAN had normal renal function (161/313 patients). Four factors, (hypertension, higher amounts of urinary erythrocytes, severe arteriolosclerosis and a higher glomerular score) which independently predicted progression (logistic regression analysis), were identified in mild disease. There was geographic variability in renal survival in patients with IgAN. When age, levels of renal function, proteinuria and blood pressure were taken into account, it showed that the variability related mostly to lead-time bias and renal biopsy indications. Amount of proteinuria more than 0.4g/24h was the only factor that was significantly related to the progression of HSN. the Hypertension and the level of renal function were found to be factors predicting outcome in patients with normal renal function at the time of diagnosis. In IgAN patients, IL-1ra excretion into urine was found to be decreased as compared with HSN patients and healthy controls. Patients with a high IL-1ra/IL-1ß ratio had milder histopathological changes in renal biopsy than patients with a low/normal IL-1ra/IL-1ß ratio. It was also found that the excretion of IL-1ß and especially IL-1ra were significantly higher in women. In conclusion, it was shown that factors associated with outcome can reliably be identified even in mild cases of IgAN. Predicting outcome in adult HSN, however, remains difficult.

Molecular features of colorectal cancer predisposition and progression

Both inherited genetic variations and somatically acquired mutations drive cancer development. The aim of this thesis was to gain insight into the molecular mechanisms underlying colorectal cancer (CRC) predisposition and tumor progression. Whereas one-third of CRC may develop in the context of hereditary predisposition, the known highly penetrant syndromes only explain a small fraction of all cases. Genome-wide association studies have shown that ten common single nucleotide polymorphisms (SNPs) modestly predispose to CRC. Our population-based sample series of around thousand CRC cases and healthy controls was genotyped for these SNPs. Tumors of heterozygous patients were analyzed for allelic imbalance, in an attempt to reveal the role of these SNPs in somatic tumor progression. The risk allele of rs6983267 at 8q24 was favored in the tumors significantly more often than the neutral allele, indicating that this germline variant is somatically selected for. No imbalance targeting the risk allele was observed in the remaining loci, suggesting that most of the low-penetrance CRC SNPs mainly play a role in the early stages of the neoplastic process. The ten SNPs were further analyzed in 788 CRC cases, 97 of which had a family history of CRC, to evaluate their combined contribution. A significant association appeared between the overall number of risk alleles and familial CRC and these ten SNPs seem to explain around 9% of the familial clustering of CRC. Finding more CRC susceptibility alleles may facilitate individualized risk prediction and cancer prevention in the future. Microsatellite instability (MSI), resulting from defective mismatch repair function, is a hallmark of Lynch syndrome and observed in a subset of all CRCs. Our aim was to identify microsatellite frameshift mutations that inactivate tumor suppressor genes in MSI CRCs. By sequencing microsatellite repeats of underexpressed genes we found six novel MSI target genes that were frequently mutated in 100 MSI CRCs: 51% in GLYR1, 47% in ABCC5, 43% in WDTC1, 33% in ROCK1, 30% in OR51E2, and 28% in TCEB3. Immunohistochemical staining of GLYR1 revealed defective protein expression in homozygously mutated tumors, providing further support for the loss of function hypothesis. Another mutation screening effort sought to identify MSI target genes with putative oncogenic functions. Microsatellites were similarly sequenced in genes that were overexpressed and, upon mutation, predicted to avoid nonsense-mediated mRNA decay. The mitotic checkpoint kinase TTK harbored protein-elongating mutations in 59% of MSI CRCs and the mutant protein was detected in heterozygous MSI CRC cells. No checkpoint dysregulation or defective protein localization was observable however, and the biological relevance of this mutation may hence be related to other mechanisms. In conclusion, these two large-scale and unbiased efforts identified frequently mutated genes that are likely to contribute to the development of this cancer type and may be utilized in developing diagnostic and therapeutic applications.

Progression of diffuse gliomas - from the first diagnosis to recurrence

Gliomas are the most frequent primary brain tumours. The cardinal features of gliomas are infiltrative growth pattern and progression from low-grade tumours to a more malignant phenotype. These features of gliomas generally prevent their complete surgical excision and cause their inherent tendency to recur after initial treatment and lead to poor long-term prognosis. Increasing knowledge about the molecular biology of gliomas has produced new markers that supplement histopathological diagnostics. Molecular markers are also used to evaluate the prognosis and predict therapeutic response. The purpose of this thesis is to study molecular events involved in the malignant progression of gliomas. Gliomas are highly vascularised tumours. Contrast enhancement in magnetic resonance imaging (MRI) reflects a disrupted blood-brain barrier and is often seen in malignant gliomas. In this thesis, 62 astrocytomas, oligodendrogliomas and oligoastrocytomas were studied by MRI and immunohistochemistry. Contrast enhancement in preoperative MRI was associated with angiogenesis, tumour cell proliferation and histological grade of gliomas. Activation of oncogenes by gene amplification is a common genetic aberration in gliomas. EGFR amplification on chromosome 7p12 occurs in 30-40% of glioblastomas. PDGFRA, KIT and VEGFR2 are receptor tyrosine kinase genes located on chromosome 4q12. Amplification of these genes was studied using in situ hybridisation in the primary and recurrent astrocytomas, oligodendrogliomas and oligoastrocytomas of 87 patients. PDGFRA, KIT or VEGFR2 amplification was found in 22% of primary tumours and 36% of recurrent tumours including low-grade and malignant gliomas. The most frequent aberration was KIT amplification, which occurred in 10% of primary tumours and in 27% of recurrent tumours. The expression of ezrin, cyclooxygenase 2 (COX-2) and HuR was studied immunohistochemically in a series of primary and recurrent gliomas of 113 patients. Ezrin is a cell membrane-cytoskeleton linking-protein involved in the migration of glioma cells. The COX-2 enzyme is implicated in the carcinogenesis of epithelial neoplasms and is overexpressed in gliomas. HuR is an RNA-stabilising protein, which regulates the expression of several proteins including COX-2. Ezrin, COX-2 and HuR were associated with histological grade and the overall survival of glioma patients. However, in multivariate analysis they were not independent prognostic factors. In conclusion, these results suggest that contrast enhancement in MRI can be used as a surrogate marker for the proliferative and angiogenic potential of gliomas. Aberrations of PDGFRA, KIT and VEGFR2 genes, as well as the dysregulated expression of ezrin, COX-2 and HuR proteins, are linked to the progression of gliomas.

Noninvasive biomarkers for early smoking related lung disease

Chronic obstructive pulmonary disease (COPD) is a slowly progressive disease characterized by airway inflammation and largely irreversible airflow limitation. One major risk factor for COPD is cigarette smoking. Since the inflammatory process starts many years prior to the onset of clinical symptoms and still continues after smoking cessation, there is an urgent need to find simple non-invasive biomarkers that can be used in the early diagnosis of COPD and which could help in predicting the disease progression. The first aim of the present study was to evaluate the involvement of different oxidative/nitrosative stress markers, matrix metalloproteinases (MMPs) and their tissue inhibitor-1 (TIMP-1) in smokers and in COPD. Elevated numbers of inducible nitric oxide synthase (iNOS), nitrotyrosine, myeloperoxidase (MPO) and 4-hydroxy-2-nonenal (4-HNE) positive cells and increased levels of 8-isoprostane and lactoferrin were found in sputum of non-symptomatic smokers compared to non-smokers, and especially in subjects with stable mild to moderate COPD, and they correlated with the severity of airway obstruction. This suggests that an increased oxidant burden exists already in the airways of smokers with normal lung function values. However, none of these markers could differentiate healthy smokers from symptomatic smokers with normal lung function values i.e. those individuals who are at risk of developing COPD. In contrast what is known about asthma exhaled nitric oxide (FENO) was lower in smokers than in non-smokers, the reduced FENO value was significantly associated with neutrophilic inflammation and the elevated oxidant burden (positive cells for iNOS, nitrotyrosine and MPO). The levels of sputum MMP-8 and plasma MMP-12 appeared to differentiate subjects who have a risk for COPD development but these finding require further investigations. The levels of all studied MMPs correlated with the numbers of neutrophils, and MMP-8 and MMP-9 with markers of neutrophil activation (MPO, lactoferrin) suggesting that especially neutrophil derived oxidants may stimulate the tissue destructive MMPs already in lungs of smokers who are not yet experiencing any airflow limitation. When investigating the role of neutrophil proteases (neutrophil elastase, MMP-8, MMP-9) during COPD exacerbation and its recovery period, we found that levels of all these proteases were increased in sputum of patients with COPD exacerbation as compared to stable COPD and controls, and decreased during the one-month recovery period, giving evidence for a role of these enzymes in COPD exacerbations. In the last study, the effects of subject`s age and smoking habits were evaluated on the plasma levels of surfactant protein A (SP-A), SP-D, MMP-9 and TIMP-1. Long-term smoking increased the levels of all of these proteins. SP-A most clearly correlated with age, pack years and lung function decline (FEV1/FVC), and based on the receiver operating characteristic curve analysis, SP-A was the best marker for discriminating subjects with COPD from controls. In conclusion, these findings support the hypothesis that especially neutrophil derived oxidants may activate MMPs and induce an active remodeling process already in the lungs of smokers with normal lung function values. The marked increase of sputum levels of neutrophil proteases in smokers, stable COPD and/or during its exacerbations suggest that these enzymes play a role in the development and progression of COPD. Based on the comparison of various biomarkers, SP-A can be proposed to serve as sensitive biomarker in COPD development.