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  • Juusela, Pirjo (Helsingin yliopisto, 2016)
    Hereditary gelsolin amyloidosis (AGel amyloidosis) is an autosomally dominantly inherited disease, mostly found in Finland, but also with worldwide distribution. Its most characteristic clinical signs are corneal lattice dystrophy, polyneuropathy, and cutis laxa, which after onset in the thirties to forties slowly progress. AGel amyloidosis is caused by a point mutation c.640G>A/T, formerly known as c.654G>A/T, in the gene coding for both cytosolic and secretory gelsolin. Cytosolic gelsolin has many roles in cellular activities. Most importantly, it modulates actin formation and participates in cell shape alterations, motility, phagocytosis, and other functions. The c.640G>A/T gene defect causes abnormal cleavage of gelsolin and eventually leads to accumulation of aberrant secretory gelsolin as amyloid fibrils. The systemic nature of this disease has been considered to result mainly from amyloid deposits accumulating in many tissues of AGel amyloidosis patients, but the pathogenesis of the disease is not yet fully understood. Patients with AGel amyloidosis reported to their physician oral problems such as sense of dry mouth and loose or cracked teeth. This information served as a starting point for this study in which we elucidated the impact of this systemic disease on oral condition, including salivary function and periodontal health. Further, oral fibroblasts and vascular smooth muscle cells were examined in vitro to clarify whether mutated cytosolic gelsolin affects their function, thus contributing to the pathogenesis of AGel amyloidosis in general and/or in relation to periodontal health. Patients were invited to the study through their patient organization and forty patients volunteered. We found that patients frequently exhibit subjective mouth dryness, i.e. xerostomia, and also decreased saliva secretion, i.e. hyposalivation. The saliva composition was also altered. Especially, secretion rate of salivary IgA was decreased, further increasing the risk for oral diseases such as oral candidiasis and caries. Histopathological analyses in minor labial salivary gland (LSG) biopsies showed gelsolin amyloid deposits, as well as atrophy of the glands, and minor inflammation. These novel histopathological LSG findings could explain at least partly the alterations in saliva secretion and composition. In one case sicca symptoms (dry eyes and mouth, i.e. xerophthalmia and xerostomia, respectively) and LSG findings had misled to the diagnosis of Sjögren s syndrome, which was later substituted with an AGel amyloidosis diagnosis. According to this study, AGel amyloidosis, on average, does not present a generally increased risk for periodontitis. However, some patients presented a high rate of disease progression, indicating that AGel amyloidosis might in some cases be associated with periodontal problems. Because both AGel amyloidosis and periodontitis progress with age, this association appears to be more common in older patients, who had lost especially their molar teeth quite commonly. In general, however, non-specific oral microbiota and common periodontal status prevail in this disease. In vitro cell studies showed that oral fibroblasts and vascular smooth muscle cells of heterozygote AGel amyloidosis patients had similar actin cytoskeleton morphology and cytosolic gelsolin distribution, migration rate, and collagen type I metabolism as control cells. Only the reaction to staurosporine, an inhibitor of protein kinases, induced minor differences in the shape change rate between the patient and control oral fibroblasts. The altered reaction of oral fibroblasts of the patients to staurosporine should be further evaluated. These results suggest that the patient oral fibroblasts and vascular smooth muscle cells mainly function normally in vitro and may not, at least via cytosolic gelsolin-associated dysfunction, contribute to the pathogenesis of AGel amyloidosis. Thus, patients with AGel amyloidosis due to their systemic disease have greater risk for oral diseases and benefit from preventive oral hygiene procedures, such as diet advice, extra fluoride, lubricants, and regular dental check-ups.
  • Jyväkorpi, Satu (Helsingin yliopisto, 2016)
    Background: Nutrition among older people is associated with functional ability and quality of life (QoL). Malnutrition is most often observed in institutionalized older people and dependent home-careclients. Furthermore, home-dwelling older people with comorbidities, including Alzheimer’s disease (AD), are a risk group for malnutrition. However, few studies have examined the detailed nutrient intakes of older people. In many studies, low nutrient intakes and low diet quality have been observed. Prevention of deterioration in nutritional status is crucial, because poor protein and micronutrient intakes increase the risk of frailty and impaire immunity. As the number of older people increases, more information on nutrition in older populations will be needed. It is important to recognize malnutrition at its early stage and to improve nutrient intake and maintain good nutritional status of older people. The effects of nutritional counseling and education on older people’s nutritional status, nutrient intakes, diet quality, and QoL have not been rigorously studied. Objectives of the study: to determine nutritional status, nutrient intakes and associated factors in both home-dwelling and institutionalized older people at various stages of functioning, and the effectiveness of tailored nutritional counseling and nutrition education on healthy home-dwelling older people’s and AD participants’ nutritional status, nutrient intakes, number of falls, and QoL . Subjects and methods: A cross-sectional study (I, II) included institutionalized (n = 374) and home-dwelling older people with varied cognition and mobility (n = 526). Five datasets were combined: home-dwelling older people participating in nutrition education and cooking classes (NC) (n = 54), participants from the Helsinki Businessmen Study (HBS) (n = 68), home-dwelling people with AD (n = 99) and their spousal caregivers (CGs) (n = 97), participants from the Porvoo Sarcopenia and Nutrition Trial (PSNT) (n = 208), and residents of Helsinki assisted living facilities (ALFs) (n = 374). The participants’ nutritional status was examined, using the Mini Nutritional Assessment (MNA), and nutrient intakes were retrieved from 1–3-day food records. Data on background information, comorbidities, and cognition were collected. The nutrient intakes were compared with recommended intakes. The adequacy of the nutrient intakes was determined by comparing micronutrient intakes with the average requirements. The sensitivity and specificity of the MNA in identifying older people with low energy and protein intakes were tested. In a follow-up study (III), the effect of NC classes on diet quality, nutrient intakes, and psychological well-being (PWB) was examined in independent and healthy, home-dwelling older people. The Nutrition and Alzheimer ’s disease (NuAD) trial (IV, V) was a 1-year randomized controlled trial (RCT) examining the effect of tailored nutritional counseling on home-dwelling AD participants’ nutrient intakes, QoL, and risk of falls. Couples received tailored nutritional guidance during home visits in a 1-year follow-up. The primary outcome measure was weight change and the secondary outcome measure comprised changes in protein and micronutrient intakes from 3-day food records, Health-Related Quality of Life (15D HRQoL), and rate of falls among participants with AD. Results: The groups of older people (I, II) differed in all their background characteristics. The prevalence of malnutrition (17%) and risk of malnutrition (68%) were highest among the ALF residents, followed by the PSNT group (3% and 60%, respectively). In the other groups, there were no malnourished participants. Among the home-dwelling AD participants, the risk of malnutrition was 43% and among the CGs 16%, whereas the respective figures in the HBS and NC classes were 9% and 7%. Insufficient intakes were most often encountered in the malnourished group, but poor protein and micronutrient intakes were also observed in people with normal nutritional status. Insufficient intakes of nutrients were associated with the female sex, cognitive decline, place of residence (institution), and immobility. Of all the participants, 77% had lower than recommended protein intakes. The participants suffering from mobility limitation and cognitive decline had the poorest nutritional status (p < 0.001; adjusted for age, sex, and comorbidities). However, low intakes of energy, protein, and micronutrients were observed in high proportions in all functional groups, those showing inadequate intakes of vitamins D, E, folate, and thiamine being the most common. Higher nutrient intakes were lineally associated with better nutritional status according to MNA, but the sensitivity and specificity of the MNA in identifying suboptimal energy and protein intakes was low. People who participated in NC classes improved their diet quality, PWB, vitamin-C, and fiber intakes postintervention compared with preintervention. The effect sizes varied between small to nearly medium (0.2-0.35). In the NuAD trial, 40% of participants with AD were at risk of malnutrition. There was no difference in weight change between the intervention and control groups during the 1-year study period. At 12 months, the protein intake improved in the intervention group, whereas it declined in the control group (p = 0.031, adjusted for baseline value, age, sex, Mini-Mental State Examination (MMSE), and body mass index (BMI). The participants’ HRQoL improved by 0.006 in the intervention group and declined by -0.036 in the control group (p = 0.007, adjusted for baseline value, age, sex, MMSE, and BMI). The annual rate of falls per person was 0.55 in the intervention group and 1.39 in the control group (p < 0.001 adjusted for age, sex, and MMSE). Conclusions: Poor diet quality, insufficient protein, and micronutrient intakes were commonly found in all functional groups of older people. The sensitivity and specificity of the MNA in identifying low energy and protein intakes was low. Tailored nutritional interventions improved diet quality, nutrient intakes, and HRQoL or PWB. In home-dwelling people with AD, falls decreased due to the intervention. 
  • Sumanen, Hilla (Helsingin yliopisto, 2016)
    Work disability among young employees is a major risk for future employment and for extending working careers. Current sickness absence and disability retirement rates indicate a rising trend in reported ill health among young adults, but still they are considered a minority in health-related research and further details are lacking. Moreover, socioeconomic differences in work disability are widely recognised among older adults, but studies among younger cohorts are scarce. The aim of this study was to examine changes in sickness absence, and socioeconomic differences in sickness absence and disability retirement among young, 18-34-year-old female and male employees between 2002 and 2013. This research is register-based and is part of the Helsinki Health Study. The City of Helsinki s personnel and sickness absence registers were used to obtain socio-demographic characteristics and individual-level information on sickness absence. Information on education was obtained from Statistics Finland s register of completed education and degrees, and information on disability retirement was derived from the national register of the Finnish Centre for Pensions. Employees under the age of 35 were considered young. Those aged 35-54 comprised the reference group in two of the sub-studies. All appropriately aged members of staff permanently and temporarily employed by the City of Helsinki between 2002 and 2013 were included in the analyses. Annual sickness absence days, overall spells and spells of 1-3, 4-14 and 15+ days, as well as disability retirement events were used as outcome variables. Education was classified on four levels annually according to the highest qualification. Occupational class was assigned to one of four categories on the basis of the job title, and income quartiles were based on the monthly salary. Joinpoint regression modelling, quasi-likelihood Poisson regression, the relative index of inequality (RII) and Cox proportional hazard models were used for the statistical analyses. The results showed an initial increase and then a decrease in sickness-absence trends during the study period of 2002-2013. The turning points were predominantly between 2007 and 2010, depending on the groups under investigation and the length of the sickness absence. Young employees had more short and intermediate spells, but less long sickness absence, than older employees. Education turned out to be the strongest determinant of sickness absence among young employees, and followed a clear gradient. The occupational class differences in short sickness absence spells were not fully consistent in that routine non-manual workers had more than the lowest occupational class, in other words manual workers. Disability retirement due to any cause, and to mental and non-mental causes, followed a clear educational gradient, and mental disorders in particular led to disability retirement among young employees. These young employees had a considerable amount of sickness absence, although the bulk of it was taken in short and intermediate spells, and less in long spells: this distinguishes the younger employees from the older ones. Findings on socioeconomic differences in work disability among young employees mainly supported the previous knowledge received among older employees. The results showed that young employees should be taken into account in the design and implementation of measures for preventing work disability. Workplace and job demands should be better matched with employees work abilities. Young employees in lower socioeconomic positions are in particular need of such extra efforts. Changes in work disability among young employees should be studied and monitored more effectively, and the resulting information should be used to evaluate earlier preventive measures and to further develop efficient ways of reducing work disability.
  • Heinonen, Juho (Helsingin yliopisto, 2016)
    Drug overdoses and poisonings are global health problems resulting in several thousands deaths annually. In out-of-hospital setting, one of the most common causes of death is an overdose of tricyclic antidepressant, such as amitriptyline. In the hospital, on the other hand, local anaesthetic systemic toxicity is one of the most feared and potentially a life-threatening complication. Both tricyclic antidepressants and local anaesthetics lack specific antidotes. However, as they all are lipophilic drugs, intravenously administered lipid emulsion has been suggested as a potential treatment for both intoxications. Originally, the proposed mechanism of action of lipid emulsion was a lipid sink that entraps lipophilic drugs and prevents their action in target tissues. Nowadays, lipid emulsion is a recommended treatment for local anaesthetic systemic toxicity in, for instance, the UK and the US in spite of the fact that its actual mechanisms of action and benefit remain uncertain. In the first study of this thesis, the incidence of local anaesthetic systemic toxicity and the adoption rates of lipid emulsion treatment in Finnish anaesthesia departments were elucidated (I). The other studies of this thesis investigate the efficacy of intravenously administered lipid emulsion in both local anaesthetic toxicity and amitriptyline. The effect on lidocaine induced central nervous system toxicity were studied in human volunteers (II). The effect of lipid emulsion on levobupivacaine intoxication in a situation simulating seizures (III), on the tissue distribution of amitriptyline (IV), and on mitochondrial respiration in bupivacaine cardiac toxicity (V) were studied in pigs. In each of these studies an assessment of the degree of the entrapment of the drug by intravenous lipid emulsion was included. The incidence of local anaesthetic systemic toxicity in Finland is low, only 0.7 per 10,000 regional anaesthesias (I). Lipid emulsion treatment is adopted to less than half of the Finnish anaesthesia departments. In human volunteers, lipid emulsion does not affect the electroencephalography changes or the subjective symptoms caused by lidocaine. Lidocaine was also not entrapped into plasma, but its volume of distribution was slightly increased (II). In pigs, lipid emulsion has no effect on levobupivacaine intoxication which is exacerbated by acidosis and hypoxaemia as measured by reversing of electrocardiogram and haemodynamics from toxic changes (III). Levobupivacaine was also not entrapped into plasma. When lipid emulsion was infused in amitriptyline intoxication, amitriptyline was slightly entrapped into circulation and the brain amitriptyline concentration was reduced by 25% (IV). After higher lipid emulsion dose than recommended, recovery from bupivacaine cardiac toxicity was improved through peripheral vasoconstriction (V). Cardiac mitochondrial respiration was also slightly improved at the same time, and bupivacaine was slightly entrapped into plasma. To conclude, this is the first Finnish study to show that the incidence of local anaesthetic toxicity is very low: 0.7 per 10,000. Lipid emulsion can reduce amitriptyline brain concentration but has no effect on local anaesthetic systemic toxicity if used in clinically recommended doses. If a higher dose is administered, lipid emulsion improves recovery from local anaesthetic toxicity through peripheral vasoconstriction in pigs. The safety of the higher dose to men remains, however, unknown.
  • Wikstén, Eeva Johanna (Helsingin yliopisto, 2016)
    Peritonsillar abscess (PTA) is the most common otorhinolaryngological infection that requires special health care management. Its treatment varies greatly due to a lack of common clinical guidelines. Tonsillectomy (TE) is performed on a portion of PTA patients, yet it remains controversial as to which PTA patients would benefit from TE. Traditional bacterial culture is ineffective at defining the causative bacteria for PTA. Rapid microarray methods have been tested, for example on serum and joint fluid samples, but not yet on pus. Most of the bacteria found in PTA are susceptible to penicillin, but, to avoid complications, antibiotics, with unnecessary broad spectrum, are frequently used instead. The aim of the first study in this thesis was to explore the microbiology of adults with PTA using a modern identification method and to find cofactors among patients with different pathogens. Using a modern DNA-based microarray method, we examined the microbial findings in the pus aspirated from 180 PTA patients. Fusobacterium necrophorum proved to be the most prevalent bacteria, occurring more frequently in younger patients; group A Streptococcus was the second most common. The microarray method seemed to work well for identifying bacteria directly from pus. In the second study, the aim was to compare the treatment modalities for PTA in countries closely related to Finland. We sent an electronic questionnaire regarding PTA treatment to all central and university hospitals in Finland, Sweden, Norway and Denmark. The study revealed diversity among treatment modalities between the four countries. To identify factors predicting a doctor ́s decision for TE among PTA patients, in the third study, we retrieved data on 819 PTA patients from a national database, which included information on whether a TE was performed within five years after a PTA diagnosis and why. The study showed that young age and previous tonsillar infections increased the probability of having a TE performed. In the fourth study, the aim was to investigate whether combining metronidazole with penicillin enhances the recovery from PTA and whether metronidazole helps prevent PTA recurrences. A total of 200 prospectively collected patients were randomised to receive either penicillin and placebo or penicillin and metronidazole. The patients filled in an electronic diary daily for the first two weeks and then weekly for the following six weeks. Most patients (90 in each group) healed well without recurrence of PTA. Thus, metronidazole neither enhanced the recovery nor prevented recurrences; furthermore, it caused unwanted adverse effects (diarrhoea and nausea). These four explorations into PTA provided valuable insight. These results make a difference not just for one patient, but for the whole health care system; the treatment is evidence-based and can be offered to those whom it serves best.
  • Hollmen, Maria (Helsingin yliopisto, 2016)
    Expanding the criteria for deceased organ donors increases the risk of delayed graft function (DGF) complicating kidney transplant outcome. Liver transplant recipients are at an increased risk for kidney injury both before and after transplantation and renal dysfunction strongly associates with morbidity and mortality. Identifying kidney injury early is crucial in achieving favorable outcome after transplantation. However, there are currently no reliable methods for predicting kidney damage in transplant patients. Neutrophil gelatinase-associated lipocalin (NGAL) is a novel marker for acute kidney injury. The aim of the study was thus to test whether kidney donor and recipient urine and serum NGAL could predict DGF and prolonged DGF lasting >14 days, and whether plasma NGAL obtained prior to liver transplantation could predict prolonged kidney injury. The studies included 99 deceased kidney donors and their 176 adult recipients and 203 consecutive liver transplant recipients. DGF was seen in 39% of the kidney grafts and the duration of DGF was prolonged in 26 cases. Long-term graft function was significantly decreased in prolonged DGF grafts. NGAL correlated with other markers that describe kidney function such as serum creatinine and GFR. Based on the results measuring serum or urine NGAL the following morning after transplantation predicts DGF and prolonged DGF. Donor urine NGAL correlated with prolonged DGF. In the liver transplant recipients, pretransplant NGAL could not predict posttransplant kidney injury. However, it predicted irreversibility of pretransplant kidney dysfunction, which is helpful in optimizing patient care and deciding whether combined liver-kidney transplantation is needed. In conclusion, measuring blood (serum or plasma) NGAL is useful in assessing kidney function after kidney and liver transplantation.
  • Nicklen, Jenna (Helsingin yliopisto, 2016)
    Background: Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) whereby the host immune system attacks against the myelin. MS affects predominantly young adults and leads to neurological disability. Although it has worldwide penetrance, MS has different incidence rates in different parts of the world. The incidence may also vary among different parts of the country, as seen in Finland. The final diagnosis of MS may often be delayed due to the heterogeneity and relapsing nature of the disease. Occurring symptoms depend on the location of the inflammation in the central nervous system. The most common form of the disease is relapsing-remitting multiple sclerosis (RRMS), in which patients typically recover from all of their symptoms. Infections are often seen before the disease progresses or relapses. Therefore, infectious agents, especially viruses, have been under suspicion for triggering an autoimmune reaction that leads to demyelination. Human herpesviruses are considered to be possible triggers for MS pathogenesis. Objective: Most patients who have been diagnosed with MS have oligoclonal bands (OCBs) of immunoglobulins in their cerebrospinal fluid (CSF). The OCBs are intrathecally produced antibodies mainly consisting of IgG, IgA, and IgM class antibodies. Clinically, the most important antibody group in OCB analysis is the IgG class, which was the main focus in this study. The objective was to study if the OCBs of patients contain antibodies against highly neurotropic and common childhood viruses: human herpesvirus-6 (HHV-6) and varicella-zoster virus (VZV). Another objective was to study if the patients, who have virus-reactive OCBs in their CSF, have some distinguishable features. The main aim was to study the possible role of these viruses in the pathogenesis of MS, focusing on the presence of antibodies during the early stages of the disease. Methods: OCB-positive CSF-serum sample pairs were systematically collected over the course of one year. A retrospective re-detection of OCBs by isoelectric focusing (IEF) was made, and HHV-6A, HHV-6B and VZV-reactive OCBs were localized with affinity driven immunoblotting. HHV-6 IgG antibodies were analyzed from the serum with immunofluorescence assay (IFA). The binding capacity of the IgG antibodies was analyzed and the infections (primary vs. past infection) were classified with avidity testing. During the clinical evaluation, the medical records of the patients were analyzed without knowing the results of the IFA or virus-reactive OCBs. This study has been ethically approved. Results: We had 18 immunocompetent adult patients with serologically primary HHV-6A or HHV-6B infections. None of them had any typical signs of a virus infection (e.g. fever or rash). Of those 18 patients 11 were diagnosed with MS with a primary infection during the early stage of the disease. Of 79 patients, 26 had HHV-6A-, HHV-6B-, or VZV reactive OCBs in their CSF. Of those 26 patients 62% were diagnosed with MS and had these virus-reactive OCBs during the early stage of MS. Patients who had any studied virus-reactive OCBs in their CSF seemed to differ from those without, including: more OCBs (p=0.001-0.003), lower protein concentration (p=0.012), and higher IgG index (p=0.007-0.014) in the CSF. They were also younger (p=0.047). Conclusion:Virus-reactive OCBs are possibly associated with MS disease pathogenesis. HHV-6 and VZV may have some association with MS disease. The pathogenesis of multiple sclerosis may have distinguishable subgroups, including pathogenesis triggered by infections with different viruses.
  • Dashkevich, Alexey (Helsingin yliopisto, 2016)
    The primary goal of the conducted research was to analyse the role of lymphatic endothelial cell in heart failure as well as in the setting of heart and lung transplantation. Our observations of lymphatic phenotype after heart and lung transplantation in human patients are the first of their kind and provide the evidence, that acute allograft rejection is associated with significant changes of lymphatic endothelial phenotype. In experimental studies, we demonstrated that ischemia-reperfusion injury activated the lymphatic endothelium in cardiac allografts. The process was mediated by interaction in the VEGF-C and VEGFR-3 axis and had direct consequences for the development of alloimmune responses. Furthermore, specific perioperative single-dose VEGF-C inhibition demonstrated beneficial effects on lymphatic vessel activation, antigen-presenting cell transport and subsequent alloimmune responses in cardiac allografts. The results of the studies, thus, demonstrate the significance of VEGF-C-VEGFR-3 signaling in promotion of alloimmunity and suggest VEGF-C/D inhibiting strategies as an alternative clinically feasible lymphatic vessel targeted immunomodulatory approach.
  • Mpindi, John Patrick (Helsingin yliopisto, 2016)
    Bioinformatic tools applied to large-scale genomic and gene expression datasets have helped in developing our understanding of the molecular basis of cancer. They have also become an important component of the drug discovery and development process, and potentially of personalized medicine for the future. Bioinformatic studies are now benefiting from the wealth of large datasets generated in laboratories through the use of new high-throughput technologies and their massive public repositories of data. As of October 2015,the GEO database (www.ncbi.nih.gov/geo/) alone comprised 1,597,783 samples across 15,040 platforms, and it is being updated on a daily basis. It is becoming evident that biological data are accumulating faster than the capacity of the scientific community to analyse, integrate and mine the data, as well as to create knowledge, understanding, and insights from the data. Thus, there is a growing need for better bioinformatic tools for analyzing, mining and modelling both local and global datasets. Many data analysis projects have called for the assembly of specialized data analysis tasks and pipelines. In the future, bioinformaticians need to be involved in both methods development and in applied bioinformatics. Methods development refers to developing new algorithms, while applied bioinformatics involves putting together existing tools/pipelines in a creative way to perform an analysis task. Bioinformatics is complicated due to the heterogeneous nature of the data, varying experimental settings, small sample sizes with little replication and the existence of many distributions in the data. There is also no uniformly accepted method for large-scale integrated data analysis. The aim of this study was to develop bioinformatic and statistical tools to perform an integrated analysis of large-scale microarray gene expression, high-throughput RNAi screening and drug testing data, as well as to demonstrate the applicability of these approaches in cancer research, drug target discovery and drug testing. First,the gene tissue index (GTI) outlier analysis method was developed to identify cancer outlier genes from large-scale microarray datasets. The need to identify genes ( outlier genes ) highly expressed in a subgroup of samples rendered some of the traditional differential expression analysis methods inadequate. The GTI method enabled the analysis and mining of outlier expression profiles from heterogeneous large-scale microarray datasets that usually contain a variable number of samples for each gene being compared. Using real and simulation study datasets, the performance of the GTI method was evaluated. We observed that the GTI performed equally well in single study settings compared to existing outlier analysis methods. Furthermore, the performance of the GTI method based on discovery studies in glioblastoma and prostate cancer was notable based on the biology of the top genes identified by the GTI. This analysis revealed many genes with outlier expression patterns, and the approach is directly applicable to the identification of drug targets and cancer biomarkers, and for cancer subtype classification studies. Secondly, there have been significant concerns over the reproducibility of high-throughput screening data in the microplate format for both RNAi screening and for drug testing data in cancer cell lines. Some of this variability may be related to the study design and statistical methods, which could be further controlled. Here, we carried out a systematic study to assess the impact of normalization methods on the reproducibility and quality of high-throughput screening data with high hit rates and drug testing with dose response data. This study revealed that the hit rate and the plate layout significantly affect the performance of normalizations, and hence the quality of high-throughput screening data. Finally, high-throughput drug testing data we reanalysed for consistency across three large-scale pharmacogenomic datasets, which were systematically processed using standardized bioinformatic analysis methods while controlling assumptions for statistical inference on large-scale data matrices. We standardized data processing and analysis methods for generating dose response curves and drug response scoring across the three datasets. For example, the concentration of one drug screened at all the three sites was merged in one standard window, and the meta-analysis was performed either between cell lines or between measurements,such as genes and drugs. The results based on standardized bioinformatic analysis of drug testing and gene expression datasets demonstrated a high correlation between two of the sites tested, and moderate agreement between the others. In conclusion, broad standardization of the methods both for laboratory measurements as well as for applied bioinformatics will be necessary to ensure greater reproducibility of biological findings in cancer research and therapeutic/biomarker discovery. I envisage that improved methods for the analysis and interpretation of large-scale datasets might accelerate our ability to advance personalised medicine.
  • Palin, Niina (Helsingin yliopisto, 2016)
    Kidney transplantation is the treatment of choice for patients with a terminal uremia in terms of the patient s outcome and cost of treatment. Despite the advances in preventing short-term graft loss, part of the kidney transplants are still lost due to chronic rejection. This study provides experimental evidence that vascular endothelial growth factor (VEGF) and activin inhibitors, in addition to perioperative simvastatin treatment may have therapeutic potential in the prevention of chronic rejection. Our results also suggest that sirolimus, an immunosuppressive agent can be used to inhibit lymphatic vessel proliferation that occurs during chronic rejection. Chronic rejection is an irreversible fibrotic process that is characterized by transplant glomerulopathy, vasculopathy, tubular atrophy and interstitial fibrosis. Ischemia-reperfusion injury and the innate immune response damage the graft immediately after transplantation and predispose the graft to later fibrosis. Cytokines and growth factors mediate fibrotic responses in kidney transplants. Lymphatic vessel proliferation also occurs in kidney transplants, but its significance is unclear. The aim of this research was to examine treatment strategies that could inhibit early injury in kidney transplants and thus limit the development of chronic rejection. This study shows that activin A, a cytokine that belongs to the TGF -β superfamily, is produced in kidney transplants early after transplantation. Activin inhibition by a soluble activin receptor limited the innate immune response and the induction of early fibrotic signaling in kidney transplants. Also, simvastatin treatment started to the transplant recipient and to the donor before transplantation limited the development of chronic rejection, although statin treatment does not protect the graft if the treatment is started later. We also examined the role of lymphatic vessels and the VEGF signaling in the development of chronic rejection. According to our results VEGF-A production is increased in renal allografts. Inhibition of VEGF-A signaling limited chronic rejection. Also lymphatic vessel growth factor VEGF-C was produced during chronic rejection. Extensive lymphatic vessel proliferation occurred in cyclosporine treated, but not in sirolimus treated kidney transplants. Newly formed lymphatic vessels were associated with the development of chronic rejection.
  • Jokinen, Riikka (Helsingin yliopisto, 2016)
    Mitochondrial DNA (mtDNA) is a small extra-nuclear genome present in all nucleated cells of the body and important for mitochondrial function. The mtDNA is a present in hundreds to thousands of copies per cell and therefore arising mutations cause heteroplasmy: the co-existence of two or more distinct mtDNA variants in the same cell. Because of these features mtDNA variants segregate mitotically in the tissues of an individual, which can lead to time-dependent changes in the relative proportions of the mtDNA variants. Mutations in the mtDNA cause diseases and most pathogenic mtDNA mutations are heteroplasmic. In heteroplasmic situations a certain threshold proportion of the mutant mtDNA must be exceeded prior to onset of symptoms. Somatic mtDNA segregation of mtDNA mutations affect whether the threshold is exceeded, and can thus be a factor in determining disease onset and severity. Some pathogenic mtDNA mutations exhibit tissue-specific mtDNA segregation patterns, but the genes and mechanisms involved in this process are unknown. The aim of this thesis was to uncover genetic regulators of tissue-specific mtDNA segregation and study their properties to gain insight into the mechanisms involved in this process. We investigated tissue-specific mtDNA segregation in a mouse model that segregates two neutral mtDNA variants. These mtDNA variants display tissue-specific mtDNA segregation in three tissue types: the liver, kidney and hematopoietic tissues. In these tissues there is selection for one mtDNA variant over the other. Using this mouse model we identified and verified Gimap3 as a modifying gene for mtDNA segregation in the hematopoietic tissues. In a follow-up study we further studied Gimap3 and a functionally related gene Gimap5. We uncovered a novel subcellular localization to the endoplasmic reticulum for the Gimap3 protein. Moreover we established Gimap5, which encodes a lysosomal protein, as another genetic modifier of mtDNA segregation in hematopoietic tissues. Taken together these results demonstrated the involvement of other organelles in the segregation of mtDNA. To study tissue-specific mtDNA segregation from another aspect we investigated the role of mitochondrial fission in this process. Mitochondrial fission has been implicated to play a role in mtDNA segregation in yeast. We utilized a dominant-negative mouse model for Dnm1l, a master regulator of mitochondrial fission. We demonstrated that expression of the dominant-negative Dnm1l modulated the mtDNA segregation specifically in the hematopoietic tissues. In conclusion, we were able discover the first genetic modifiers for tissue-specific mtDNA segregation in mammals. These findings can be utilized to guide future research aiming to uncover the molecular mechanisms of this process, which can ultimately elucidate the genetics of pathogenic human mtDNA mutations.
  • Hiivala, Nora (Helsingin yliopisto, 2016)
    Until recently research on patient safety (PS) focused on secondary care, and little was known about the risks that patients face in primary care and especially in dental care. Only few studies have hitherto focused on the understanding of either the patients or their families about safety in dentistry. The objectives of this thesis were to identify types of dental patient safety incidents (PSIs), the contributory factors that played a role on the origin, development of PSIs, or identify the factors that increased the risk of PSIs, the mitigating factors against PSI, suggested by dentists and PS practices in use in their clinics. Furthermore, this thesis aimed at exploring whether patients or their families are able to observe PSIs in their own dental care. The study findings were derived from two datasets: 1) The first dataset was obtained from an internet-based questionnaire, sent in 2010 that requested practicing dentists to respond to questions on any PSIs that had occurred during the preceding year and any incident mitigating factors. A total of 1041 dentists responded (response rate 54%) and almost one third reported PSI(s) (n=872). 2) The second dataset was compiled from national data on patients or their family complaints and other notifications made against individual dental practitioners or dental practice units (n=948) for six Regional State Administrative Agencies (AVIs) and also from the National Supervisory Authority for Welfare and Health (Valvira) in Finland from 2000 to 2012 inclusive. The study used quantitative and qualitative research methods. Qualitative analyses (root cause analysis and document analysis) aimed to find emergent themes of dental PSIs and the factors related to them. The quantitative analyses examined several variables related to incident types, which included the contributing factors, the mitigating factors and their associations with dentists characteristics. The detected dental incident types in Finland are in many ways identical to reports from other countries. The two datasets provided somewhat different pictures of PSIs in dentistry. The dentists incident reports mostly captured incidents with relatively low severity, whereas patient complaints and supervisory data of healthcare regulators captured rarer but more serious events. This study showed that PS in dentistry is a complex and multidimensional issue and it relates to all aspects of care; diagnostics, treatment, devices and premises, medications, leadership and management, infection control, teamwork, communication, practitioner characteristics and patient characteristics. All dental PSIs in both datasets had a broad array of contributing factors including both human factors and latent system-factors. Compared to the total number of annual dental visits in Finland, severe dental PSIs are rare. However, less severe PSIs are more common, especially in prosthetics, dental surgery, endodontic and restorative treatments. According to dentist reports no significant difference existed in the incident rate between public and private dental practice. Yet two thirds (68%) of all studied patient complaints and other notifications concerned private professionals, whereas one third concerned public dental providers (32%). Most patients or family lodged complaints were lodged against individual dental professionals and only a minority was issued against dental practices or organizations. Nine out of ten complaints were made against dentists, the majority being general dental practitioners. Most (83%) dental professionals were complained about only once during the study period, however, a small number of dentists were responsible for a notable proportion of complaints from patients or received notifications concerning dentistry. These complaint-prone dentists carried a significantly higher risk for PSIs than did other dentists. The study also showed that patients and their families can be observant and are capable of identifying several incidents and hazardous circumstances in their dental care. Even serious safety risks that were otherwise probably not captured can be detected. The results show a relatively high prevalence of preventable incidents in Finnish dentistry. On the other hand, several mitigating factors had already implemented every day dental practice to safeguard patients in Finland. The problem is that the active use of novel methods varies between individuals and organizations. Patient protection in dentistry can be further enhanced by creating a more open PS culture. Such a culture should include improved incident reporting and should focus on learning from adverse events and also near misses. Anonymous, easy-to-use and blame-free reporting systems tailored for the specific features of dentistry might facilitate reporting. Development of proactive ways to intervene against complaint-prone dentists early and effectively to prevent an escalation of problems is also needed. PS issues should be implemented in undergraduate, post-graduate and continuing professional training. Further research should use different datasets, target groups (health care professionals, patients and their families), several PS research methods and include physical, emotional, social and economic consequences of dental incidents. Keywords: Patient safety, dentistry, incident type, degree of harm, prevention, patient complaints, malpractice
  • Saurus, Pauliina (Helsingin yliopisto, 2016)
    Background: Diabetic nephropathy (DN) is a renal complication of diabetes and a common cause of end-stage renal disease (ESRD). DN presents in its earliest stage with low levels of albumin in the urine (microalbuminuria) and develops into overt albuminuria as the disease progresses. Podocyte loss due to detachment or apoptosis has a central role in the pathogenesis of DN, but the mechanisms are not fully understood. The studies in this thesis aimed to increase the knowledge of the pathophysiological mechanisms and molecular pathways leading to podocyte apoptosis in DN by studying three molecules that are expressed in podocytes, SH2-domain-containing inositol polyphosphate 5-phosphate 2 (SHIP2), 3-phosphoinositide-dependent kinase 1 (PDK1) and cyclindependent kinase 2 (CDK2). Results: Lipid phosphatase SHIP2 was identified as an interaction partner of CD2AP, a protein known to be involved in the regulation of apoptosis in podocytes. We found that overexpression of SHIP2 in cultured podocytes reduced the phosphorylation of the major cell survival kinase Akt in response to insulin and increased apoptosis. We also observed that the expression of SHIP2 was upregulated in glomeruli of insulin resistant obese Zucker rats prior to the onset of proteinuria, suggesting a role for SHIP2 in the development of podocyte injury. In contrast, we found that the expression of PDK1 and CDK2 was downregulated in obese Zucker rats before they had developed proteinuria. We also observed that treatment of human podocytes with sera from normoalbuminuric type 1 diabetic (T1D) patients with high lipopolysaccharide (LPS) activity downregulated the expression of PDK1 and CDK2. LPS treatment of mice in vivo also reduced PDK1 and CDK2 expression. LPS-induced downregulation of PDK1 and CDK2 was prevented both in vitro and in vivo by inhibition of the toll-like receptor (TLR) pathway using immunomodulatory agent GIT27. Knockdown of either PDK1, or CDK2 inhibited antiapoptotic Akt pathway, stimulated the proapoptotic p38 MAPK pathway and increased podocyte apoptosis. Conclusions: Given the central role of the PI3K-dependent Akt signaling pathway in regulating cell survival, our findings suggest that SHIP2, PDK1 and CDK2 regulate apoptosis in podocytes by modulating the activity of the PI3K-dependent Akt signaling pathway.
  • Tapiovaara, Laura (Helsingin yliopisto, 2016)
    Upper respiratory infections are among the most common ailments in humans. Evidence for mechanisms suggests that specific probiotic bacteria could reduce the risk and symptoms of these infections. However, the clinical evidence of probiotics in the upper respiratory tract, especially when colonization and the etiological effects are considered, is sparse. In addition, the safety of probiotics requires constant assessment. This thesis investigated the recovery of probiotic Lactobacillus rhamnosus GG (L. GG) from the upper respiratory tract and its effects on pathogens in this tract. In addition, the thesis assessed the adverse events of L. GG alone or in combination with other probiotics (Bifidobacterium lactis BB-12 [BB12], or Lactobacillus rhamnosus Lc705 [Lc705], Propionibacterium freudenreichii JS [PJS], and/or Bifidobacterium breve 99 [BB99]). In a randomized, double-blinded, placebo-controlled study, 40 children consumed per oral L. GG or a placebo (1:1) prior to surgery in which their adenoids were removed and a possible middle ear effusion (MEE) was collected. L. GG was recovered from both the adenoid tissue and MEE, but it did not affect the findings of human rhinovirus (HRV) or enterovirus (EV) in the samples compared to the placebo. In addition, the analysis of the bacterial pathogens in the MEE showed similarities in both intervention groups. No differences between the groups emerged in respiratory or gastrointestinal (GI) symptoms prior to the surgery or in pain or bleeding after the surgery. In another randomized, double-blinded, placebo-controlled trial, an experimental HRV infection model was used in 59 healthy adult volunteers to investigate the effects of the oral consumption of live, heat-inactivated L. GG on the HRV load in nasopharyngeal lavage samples. The correlation of the HRV load to the subjects clinical symptom scores was assessed. The use of live or inactivated L. GG did not result in statistical differences in the HRV load, but a tendency to lower loads in the L. GG groups was noted. The HRV load positively correlated with the total symptom scores on day 2 and day 5 after inoculation. In the fourth study, individual participant data from six randomized placebo-controlled probiotic studies were analyzed for adverse events (AEs), as distributed by the Common Terminology Criteria of Adverse Events (CTCAE). Data on 1,909 healthy subjects, including children, young adults, and elderly participants, revealed no statistical differences in AEs between the groups that consumed L. GG alone, L. GG in combination, or the placebo. A detailed analysis of three specific categories (respiratory diseases, gastrointestinal diseases, and infections) did not yield any statistical differences in AEs between the probiotic and placebo groups. Based on the results, we concluded that L. GG was able to colonize the upper respiratory tract, but it had no effects on the levels of viral or bacterial pathogens or on the frequency of clinical symptoms in the subjects during either the intervention or the follow-up period. The nasopharyngeal HRV load was positively correlated with the subjects total symptom score. The use of L. GG alone or in combination did not result in AEs in the population of healthy children, young adults, and elderly participants.
  • Chen, Ping (Helsingin yliopisto, 2016)
    Transcriptome, defined by the collection of all RNA molecules in a cell, acts as a central bridge that transfers genetic information into molecular functions. Transcriptome regulates the biological characteristics in all living organisms, thus it is one of the most important research subjects in biology. RNAs are transcribed at different levels tightly controlled by cellular conditions. This produces great diversity in cellular transcriptome dynamics, introducing a lot of complexity to the transcriptomic research. Though tremendous challenges exist, the study of transcriptome dynamics is essential to the understanding of the complex systems within the cells and cellular behavior. The dynamics of transcriptome can be investigated by high-throughput technologies, such as microarrays and RNA-sequencing. The large amounts of data introduces challenges to data management, analysis and interpretation. To generate biologically testable and conclusive results, efficient computational methods are urgently needed. This thesis includes theoretical and methodological research. The theoretical part of the research comprehensively studies the characteristics of gene expression, the splicing of ancient and novel exons during the evolution by comparative analysis on transcriptomic data of nine tissues from five species. The methodological research includes new methods developed to solve the research questions related to the study of transcriptomic dynamics in evolution and cancer. The main methods developed in this thesis are 1) exon age classifier, which is able to classify exons according to their evolutionary time, providing the basis for the theoretical study in this thesis; 2) MEAP, a new exon array preprocessing method for expression quantification at multi-levels; 3) PSFinder, a new approach to identify patient prognostic subgroups from treatment naive tumor samples based on their transcriptomic profiles and associated clinical survival times. The theoretical part gives a comprehensive view on the mechanisms of dynamic changes during the evolution of the transcriptome, which provides a solid theoretical basis to the methodological part. The application of MEAP and PSFinder to high-grade serous ovarian cancer revealed a small set of isoform markers with distinct expression profiles for patient prognosis stratification. In combination with experimental validation, the results demonstrate the applicability of these methods in the quantification and stratification of tumor transcriptome dynamics, which provides new insights to the clinical diagnosis and precision medicine for human cancers.
  • Toivonen, Sanna Charlotta (Helsingin yliopisto, 2016)
    Ihmisen alkion kantasolut (hESC) ja ihmisen uudelleen ohjelmoidut monikykyiset kantasolut (hiPSC), yhteiseltä nimeltään ihmisen monikykyiset kantasolut (hPSC), pystyvät jakaantumaan rajattomasti solumaljalla sekä erilaistumaan kaikiksi aikuisen ihmisen solutyypeiksi. hPSC:t ovat ainutlaatuinen solulähde ihmisen kehitysbiologian tutkimukseen, tautimallinnukseen sekä regeneratiivisen lääketieteen käyttöön. hiPSC:t saattavat tulevaisuudessa mahdollistaa autologiset solusiirteet sekä tautispesifisten solujen, kuten geneettisestä maksasairaudesta kärsivien ihmisten hepatosyyttien tuotannon. Maksasairaudet ovat johtava kuolinsyy maailmanlaajuisesti ja ainoa hoitomuoto vakaviin maksasairauksiin on elinsiirto. Maksa on ihmisen aineenvaihdunnan keskus ja päävastuussa lääkeainemetaboliasta. Tämän vuoksi on erityisen tärkeää löytää uusia, parempia maksasolumalleja tautien patologiamekanismien tutkimiseen, lääkeaineiden kehittelyyn sekä uusien lääkeaineiden myrkyllisyyden arviointiin. Hepatosyyttejä onkin jo onnistuneesti erilaistettu hPSC:sta, mutta nykyiset menetelmät eivät pysty tuottamaan täysin toiminnallisia soluja. hPSC:n erilaitumista in vitro ohjataan stimuloimalla soluja sytokiineilla ja kasvutekijöillä, joiden tiedetään ohjaavan solujen erilaistumista myös in vivo. Tämän väitöskirjatyön ensimmäinen tavoite oli tutkia eri hPSC linjojen erilaistumispotentiaalia hepatosyyteiksi. Toinen tavoite oli tutkia miten Aktiviini/Nodal ja Wnt signaalien aktivoinnin kesto maksaerilaistuksen ensimmäisessä vaiheessa, definitiivisen endodermin (DE) erilaistuksessa, vaikuttaa DE solujen maksa- ja haima- erilaistuspotentiaaliin. Viimeisenä tavoitteena oli selvittää miten eri soluväliaineen proteiinit, kuten laminiinit, ja erilaiset kolmiulotteiset (3D) soluviljely-ympäristöt vaikuttavat hPSC:n hepatosyytti- erilaistukseen. Kaikki tutkimuksessa käytetyt hESC ja hiPSC linjat erilaistuivat hepatosyyteiksi. Tuloksemme kuitenkin osoittivat, että ne hiPSC linjat, jotka ovat uudelleenohjelmoitu genomiin integroituvilla retroviruksilla, omaavat potentiaalin transgeenien uudelleenaktivoitumiseen, mikä estää kyseisten linjojen mahdollisen kliinisen käytön. Lisäksi yksi retroviruksilla perustettu linja osoitti jatkuvaa transgeenista KLF4 ilmentymistä, mikä selkeästi häiritsi kyseisen linjan erilaistumista. Näistä syistä hiPSC linjojen teossa on siirrytty käyttämään pääasiassa menetelmiä, joissa transgeenit eivät integroidu solun genomiin. DE solut ovat yhteinen esisoluaste sekä haima- että maksasoluille. DE soluja voidaan erilaistaa hESC ja hiPSC linojoista aktivoimalla Aktiviini/Nodal sekä Wnt signaalireittejä. Tuloksemme osoittavat, että lyhytkestoinen Wnt signaalin aktivoiminen DE erilaistuksen aikana on suosiollista haimaerilaistukselle, kun pidempi Wnt aktivointi puolestaan tehostaa hepatosyyttien erilaistumista. Wnt aktivaatio myös tuki DE solujen pitkäaikaista viljelyä. Terveessä aikuisessa maksassa hepatosyytit eivät jakaannu, mutta kehityksen aikana epäkypsät hepatosyytit, heptaoblastit, jakaantuvat kiivaasti. Lisäksi aikuisessa maksassa hepatosyytit ovat hyvin heterogeenisiä ja hepatosyyttien toiminnallisuus riippuu solujen sijainnista maksassa. Hepatosyyttien toimintaa ohjaavat sekä signaalimolekyylit että soluväliaineen proteiinikoostumus. Tuloksemme osoittivat, että laboratoriossamme valmistettu laminiinirikas soluviljelyvalmiste, JAR-matrix, tuki hPSC linjojen erilaistumista hepatoblasteiksi. Lisäksi geeni-ilmentymisanalyysit osoittivat, että eri 3D soluviljely-ympäristöt tukivat eri maksageenien ilmentymistä; proteiinirikas Matrigeeli edesauttoi Albumiinin ilmentymistä ja solujen albumiinin eritystä, kun taas ainoastaan fysikaalinen 3D tuki edesauttoi metaboliaentsyymeitä koodaavin geenien ilmentymistä. Tuloksemme osoittavat, että soluja ympäröivät proteiinit että 3D- ympäristö säätelevät maksasolujen toiminnallisuutta. Tämä väitöstyö tarjoaa arvokasta biologista ja teknistä tietoa, joiden avulla maksasolujen erilaistusta hPSC linjoista voidaan tulevaisuudessa tehostaa.
  • Reponen, Elina (Helsingin yliopisto, 2016)
    Background: Preoperative risk assessment and reliable outcome reporting are vital for improving quality of care and patient safety. Studies on neurosurgical patients are surprisingly scarce, and no prospective reports on unselected elective craniotomy patients exist. The objectives of this study were to review the literature on the use of preoperative risk-assessment scores in elective cranial neurosurgery and to study preoperative risk prediction, short-term outcome reporting, and patient satisfaction in the first unselected, prospective cohort of adult elective craniotomy patients. Patients and Methods: We performed a systematic review of 25 studies on five preoperative scores [The American Society of Anesthesiologists physical status classification (ASA) score, the Karnofsky Performance Score (KPS), the modified Rankin Scale (mRS), the Sex, Karnofsky, ASA, Location, and Edema (SKALE) score, and the Charlson comorbidity score] in predicting outcome in elective cranial neurosurgery. We enrolled a prospective, unselected cohort of 418 adult elective craniotomy patients in the Department of Neurosurgery, Helsinki University Hospital. Evaluation of routinely collected preoperative data, original ASA score, Helsinki ASA score, and their combinations revealed their ability to predict in-hospital new central nervous system (CNS) deficits as well as systemic and infectious complications after elective craniotomy. We evaluated the reliability and accuracy of patient-reported outcomes, postoperative mRS scores, and mRS-score differences in reflecting short-term outcome. Overall patient satisfaction rate was determined, as were associations between high or low patient satisfaction and short-term postoperative outcome. Results: Evidence as to the applicability of preoperative risk-assessment scores in elective cranial neurosurgery is scarce, with KPS receiving the most support in the literature. None of the scores predicted all postoperative outcomes; the most applicable risk score varied with the outcome measure selected. The in-hospital mortality rate was 1.0% and the 30-day rate was 2.4%. In-hospital systemic and infectious complications occurred in 6.7% of patients, and new CNS deficits in 11.2%. Advanced age, preoperatively elevated C-reactive protein (CRP) level, and high Helsinki ASA class were independent predictors of systemic and infectious complications. A combination of these variables identified one-fourth of the patients with systemic and infectious complications (p=0.005, OR 4.8, CI 1.5-15.9, AUC 0.766) and was associated with prolonged intensive care unit (ICU) stay (p=0.018) and hospital stay (p=0.004). The rate of overall complications was 46.4%, and the rate of major complications was 18.2%. Perioperative changes in mRS scores were inconsistent: among patients with no complications, the mRS score increased for 17.1% at hospital discharge and for 23.8% at 30 days. Moreover, 28.0% of patients with major complications showed no increase in mRS scores at hospital discharge. Associations between patient-reported postoperative subjective deterioration in functional status and both major and overall morbidity were significant. Furthermore, a simple unweighted composite score of PROs was more sensitive and specific than was 30-day dependent functional status (mRS score ≥3) in detecting both major and overall morbidity. In our cohort, 93.8% rated their overall satisfaction as good or excellent. Even 9 of 10 patients with postoperative major morbidity rated their satisfaction as high. Low patient satisfaction was associated neither with major (p=0.054) nor with overall (p=0.215) morbidity. Conclusions: Strong evidence supporting the use of any preoperative risk score in elective cranial neurosurgery is lacking. The Helsinki ASA score seems more suitable than the original ASA score for elective craniotomy patients, especially in combination with other preoperative risk predictors, but only for systemic and infectious complications. The rate of major complications in our cohort was moderately low considering the average age, comorbidities and operated lesions of the patients in our unselected study cohort. The postoperative mRS score and mRS-score differences were inconsistent with recorded complications, whereas PROs seem promising tools for outcomes reporting. Overall patient satisfaction was high, even in patients with complicated outcomes, and thus patient satisfaction is a poor proxy for treatment outcome and quality of care in elective cranial neurosurgery.
  • Quintero, Ileana B. (Helsingin yliopisto, 2015)
    Prostatic acid phosphatase (PAP) has been linked to prostate cancer since the mid-1930s. The main research approach of PAP over that time has been based on its role in the human prostate. The regulatory mechanisms of expression of the PAP gene have also been studied, giving us information about the regulatory elements in the gene and the transcription factors that affect the gene expression in the prostatic tissue. However, little was known until recently about this protein s role and physiological function in other tissues. Our group generated and used a PAP-deficient mouse and was able to show that PAP is expressed in dorsal root ganglia (DRG) and spinal cord in mice. This is the same protein as thiamine monophosphatase (TMPase) whose enzymatic activity has been used for five decades to mark primary sensory neurons. In these tissues, PAP acts as an ecto-5'-nucleotidase and is able to dephosphorylate AMP to adenosine, and therefore produce an anti-nociceptive effect due to the binding of adenosine to the A1-adenosine receptor. We analyzed the ACPP gene, which enabled us to describe a new transmembrane isoform for PAP (TMPAP). This novel PAP isoform is produced by alternative splicing of the 11th exon of the ACPP gene. The alternative splicing is present in species such as the human, mouse and rat. The newly discovered isoform is widely expressed in human and mouse tissues and contains a tyrosine sequence (YxxΦ) in its carboxyl-terminus, which directs the protein to endocytosis. We have also corroborated its functionality by co-localization studies with different organelle markers in the endosomal/lysosomal pathway (I). The generation of a PAP-deficient mouse also enabled us to study the function/s of PAP in vivo. The lack of PAP in this mouse model led to the gradual changes in the mouse prostate that finally culminated with the development of prostate adenocarcinoma at the age of 12 months. Microarray analyses of different tissues that compared the PAP deficient mouse with the wild type (WT) mouse revealed changes in genes related to the vesicular trafficking, which support our previous results and led us to the conclusion that TMPAP could be involved in the regulation of the vesicular trafficking. We also detected the interaction between TMPAP and snapin, a SNARE (Soluble NSF Attachment Protein Receptor) associated protein, by yeast two-hybrid screening, co-localization and FRET (Förster resonance energy transfer) analysis. We concluded that, the disruption of this interaction in the PAP-deficient mouse leads to a disturbance in the vesicular transport of the cell and to the development of prostate adenocarcinoma in the PAP-deficient mouse prostate (II). Furthermore, we showed that the PAP-deficient mice present multiple behavioral and neurochemical alterations including increased size of brain lateral ventricles, hyperdopaminergic deregulation, and altered GABAergic transmission, symptoms that indicate that PAP also disturbes the normal function of the central nervous system (III). Snapin protein in the brain has been described as a protein important for the vesicular transport and for the fusion of vesicles with the plasma membrane, and we observed that the lack of PAP in GABAergic neurons leads to a change in the localization of snapin in the PAP-deficient mouse (III), which could indicate that as in the prostate a dysregulated vesicular trafficking could be the reason for the detected phenotype. The discovery of the new TMPAP and its localization in the endosomal/lysosomal pathway enabled an understanding of the phenotypic changes that occur in the PAP-deficient mouse. We hypothesized that TMPAP regulates vesicular trafficking by interacting with snapin, and its deficiency leads to a dysregulation of the endo-/exocytosis cycle, which produces the observed alterations in the mouse organs and tissues. The results obtained throughout this research project have opened up new lines of research related to PAP physiological function, and a deeper understanding of the expression, regulation and function of this protein could lead to new clinical applications.
  • Ristikankare, Anne (Helsingin yliopisto, 2015)
    Acute kidney injury in cardiac surgery Acute kidney injury (AKI) is a serious complication in cardiac surgery. It occurs in up to 40 % of procedures according to the latest consensus definition of AKI. It has been associated independently with increased mortality, morbidity, and hospital costs. Even a small increase in serum creatinine is associated with mortality, and in severe AKI requiring renal replacement therapy mortality has increased over 50 %. Serum creatinine remains the benchmark of kidney function, even its lack of sensitivity and late increase in acute kidney injury. A novel biomarker of kidney function, cystatin C, has been claimed to be less affected than creatinine by patients age, sex, and muscle mass. We studied cystatin C in elderly cardiac surgery patients and in heart transplant patients to find out if cystatin C can detect AKI earlier than creatinine after surgery. There was no significant difference between these markers, and these results are in accordance with majority of other studies of cystatin C in cardiac surgery patients. Creatinine is still the primary marker of kidney function in AKI. The pathophysiology of AKI in cardiac surgery is multifactorial and injury to kidneys can occur during pre-, intra-, and postoperative period. The main risk factors are other comorbidities of the patient, especially preoperative chronic kidney failure, and hypoperfusion of the kidneys during perioperative period. The possible causes of hypoperfusion are hypotension, cardiac low output syndrome, and the use of the cardiopulmonary bypass. N-acetylcysteine is a drug, which has antioxidant and vasodilatory properties. We conducted a randomized, double blind study to find out if it can protect kidneys in cardiac surgery patients with preoperative renal dysfunction. N-acetylcysteine was administered intravenously during intra- and postoperative period, but had no effect on postoperative renal function. Meta-analyses on this subject published after our study has come to same conclusions. A novel inotrope, levosimendan, was studied in 60 coronary bypass grafting patients with left ventricle dysfunction to discover its effect on the kidneys. In this randomized, double blind study there was no significant difference in creatinine or cystatin C concentrations between the patients in the control or levosimendan groups, but there was a tendency towards preserved renal function in the levosimendan group. Larger randomized trials are needed to prove the renoprotective effects of levosimendan in cardiac surgery. There are no drugs that have proved to prevent AKI in cardiac surgery at the present time. The methods to prevent AKI are to avoid interventions known to be harmful to the kidneys and to optimize hemodynamics and hydration. A better understanding of the pathology of human acute kidney injury may produce more protective strategies in the future.
  • Puranen, Taija (Helsingin yliopisto, 2015)
    Nutritional problems such as poor appetite and unintentional weight loss are common among individuals with Alzheimer’s disease (AD), and their older spousal caregivers with comorbidities may also be at risk of malnutrition. The objective was to study the nutrition of people with AD and their spouses, and to compare nutrient intake to recommended levels, and to investigate the association between the caregiver’s gender and the couples’ nutrition. A randomized, controlled trial was conducted to examine the effectiveness of nutritional guidance on the AD victim’s weight, nutritional status (MNA), energy and nutrient intake (three-day food diaries), quality of life (HRQoL with 15D) and falls. A total of 99 couples were randomized into this trial. The intervention group (IG) received tailored nutritional guidance 4-8 times at their homes over one year, and the control group (CG) received booklet on healthy nutrition. The primary outcome measure was the AD sufferer’s weight change. The mean age of AD was 77.4 years (SD 5.6), and spouses 75.2 years (SD 7.0). At baseline, 44% of the AD, and 16% of the spouses were at risk of malnutrition, whereas 56% and 84% had a good nutritional status. At baseline, the mean energy intake among those with AD was 1897 kcal (SD 416) among the men and 1313 kcal (SD 340) among the women, and the respective figures for spousal caregivers were 1605 kcal (SD 458) and 1536 kcal (SD 402). Among AD, 47% of the men and 71% of the women had a protein intake below 1g /bodyweight/kg, the respective figures for the spouses being 71 and 49%. In addition, almost half of the participants had a vitamin C intake of less than the recommended. The male gender of the caregiver was associated with poor energy and nutrient intake in the couple. Tailored nutritional guidance had no effect on the weight of those with AD, but improved their nutrient intake and HRQoL. The mean change in protein intake was 0.05 g per body/kg in kg (95% CI -0.06 to 0.15) in the IG, and -0.06 g per body/kg in the CG (95% CI -0.12 to 0.02), p = 0.031. The respective changes in mean calcium intake were 85 mg (95% CI -24 to 194) and -17 mg (95% CI -98 to 65), p = 0.025. HRQoL improved by 0.006 (95% CI -0.016 to 0.028) in the IG, and declined by -0.036 (95% CI -0.059 to 0.013) in the CG, p = 0.007. In addition, those in the IG with AD had a significantly lower number of falls than those in the CG during the one year: 0.55 (95% 0.34 to 0.83) and 1.39 (95% CI 1.04 to 1.82) falls per person, p < 0.001, respectively. The community-dwelling ID sufferers and their spousal caregivers were very heterogeneous in terms of nutrition. Male caregivers may need tailored guidance on food-related activities. Tailored nutritional guidance improves both nutrition and the quality of life among those with AD, and may also prevent falls, and should therefore be part of their everyday care.