Lääketieteellinen tiedekunta


Recent Submissions

  • 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.
  • 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.
  • 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.
  • 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
  • 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.
  • 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.
  • 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.
  • 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.
  • Kivistö, Kaisa (Helsingin yliopisto, 2015)
    Illicit use of prescription opioids has increased markedly in recent years, especially in Europe and North America. In Finland, the number of opioid problem users constantly increased through the 2000s, levelling off in 2012. Buprenorphine is a semisynthetic opioid that was originally administered as an analgesic, but later also used in opioid detoxification and maintenance treatment. However, buprenorphine abuse has been reported in many countries. In Finland, buprenorphine is the most common injection drug. Buprenorphine use in late pregnancy leads to neonatal abstinence syndrome (NAS) in roughly 60% of newborns. Data on buprenorphine-exposed children´s health after the neonatal period is scarce. Our aim was to identify the health problems of these children from infancy to three years of age. The study population comprised altogether 108 children with a positive drug screen for buprenorphine as a newborn. Children were born in 2000s in Helsinki University Central Hospital (HUCH). One main finding was that pediatricians observed multiple types of child abuse and neglect in the study population in HUCH. Pediatricians made altogether 70 child welfare reports. Repeated failure to come to an appointment, which was considered medical neglect, constituted 64% of the child welfare reports. In four children, physical abuse was suspected. Another main finding was that buprenorphine-exposed children had significantly more early childhood caries than control children. The study raised concern for dental neglect in buprenorphine-exposed children. We also discovered that 10% of buprenorphine-exposed children had been diagnosed with strabismus and 5% had a major congenital anomaly. Of 102 children, four had an umbilical or inguinal hernia and three had infantile pyloric stenosis. The psychological study revealed poorer cognitive abilities in buprenorphine-exposed children at three years old than in controls as well as reduced performance of mother-child dyads in terms of emotional availability and perceived maternal self-efficacy. In the MEG study, somatosensory and auditory evoked potentials did not show significant differences between the buprenorphine-exposed group and the control group. Prenatally buprenorphine-exposed children exhibit more early childhood caries and dental neglect than control children. In addition to dental neglect, the children are exposed to multiple types of child maltreatment as well as to unfavorable emotional features in the caregiver-child relationship. Based on health and maltreatment issues revealed here, a pediatric follow-up with a multi-professional team, including a dentist, is essential.
  • Koho, Petteri (Helsingin yliopisto, 2015)
    Psychological factors are implicated in the transition from acute to chronic back pain as well as in predicting return to work in low back pain patients. Research shows that pain-related fear can be more disabling than pain itself. Earlier studies have demonstrated that fear of movement and fear of (re)injury are better predictors of functional limitations than biomedical parameters. During clinical assessment chronic pain patients frequently demonstrate a variety of pain-associated behaviours. These behaviours may also influence development of chronic pain and disability. The purpose of the research project was; to develop a functional assessment tool for the assessment of pain behaviour and to investigate the relationship between pain behaviour, fear of movement, physical function, and disability, and to study the association between fear of movement and leisure time physical activity (LTPA) among chronic pain patients, and to estimate the measurement properties of the Finnish version of the Tampa Scale of kinesiophobia (TSK-FIN) among chronic pain patients, and to investigate fear of movement among the general population. The functional assessment tool for the assessment of pain behaviour showed good reliability. There was a strong correlation between pain behaviour and subjective pain report and disability and moderate correlation to pain behaviour. The inverse associations between total pain behaviour and physical function tests were strong. The internal consistencies were good and test-retest reliability of the TSK-FIN was excellent for both paper and computer versions. The mean difference between the computer and the paper version was 1.9. However, in terms of individual variability, 62% varied by less than 3 points and 44% by less than 2 points. The level of kinesiophobia was associated with disability and depressive symptoms. Kinesiophobia and leisure time physical activity were inversely associated. For the purpose of the studying the effect of pain management program, the patients were classified into three groups based on distribution of the TSK-FIN. At baseline, the mean LTPA index of the high kinesiophobia group was lower than in the low and medium kinesiophobia groups. At the 6-month follow-up, patients with high kinesiophobia had increased their physical activity to the same level as the other groups. This change was maintained up to the 12-month follow-up. Among general population, men over 55 and women over 65 had higher scores than younger ones. The presence of cardiovascular disease, musculoskeletal disease or mental disorder was significantly associated with a higher TSK-FIN score compared to the absence of the aforementioned disorders. Among general population, 14.2% received the generally used cut-off point 40 points or more for increased kinesiophobia. Conclusion: The results of this research project suggest that both the assessment of pain behaviour and the TSK-FIN demonstrated acceptable reliability. Among patients with musculoskeletal pain, the fear of movement and leisure time physical activity are inversely related. A pain management program seems to have favourable effect on the fear of movement and physical activity. Among general population age and TSK-FIN score are associated. Among general population, 14 % scored over cut-off point 40 points or more.
  • Kandolin, Riina (Helsingin yliopisto, 2015)
    Cardiac sarcoidosis (CS) and giant cell myocarditis (GCM) are underdiagnosed inflammatory myocardial diseases. Sarcoidosis is a systemic disease characterized by granuloma formation and subsequent tissue scarring in various organs, most commonly in the lungs. In majority of cases, lung sarcoidosis is a self-limiting disease whereas cardiac involvement carries a poorer prognosis due to heart failure and malignant arrhythmias. GCM is a rare, frequently fatal myocardial disease designated by widespread myocardial inflammation and necrosis. Prior data concerning epidemiology, outcome with contemporary treatment and ICDs, and the effect of novel diagnostic methods is scarce and I set out to study these questions. All cases with histologically confirmed CS and GCM in Finland between 1988 and 2014 were identified and analyzed. A marked increase in the detection rate of CS over the last 26 years was found. In the era of modern diagnostic imaging and increased awareness, the annual detection rate of CS is over 50 times higher than before. CS most commonly manifests with atrioventricular block (AV-block). What is more, CS and GCM together explain 25% of initially idiopathic 2nd to 3rd degree AV-blocks in adults aged 18-55 years. Other principal manifestations of CS are heart failure and ventricular arrhythmias. Two thirds of patients with CS present without prior diagnosis of sarcoidosis, an entity called clinically isolated CS. The mean age of CS patients was 51 years and two thirds were female. The diagnosis was based on endomyocardial biopsy (EMB) in 50% of cases and on extracardiac biopsy combined with cardiac imaging findings (cardiac magnetic resonance (CMR) or positron emission tomography (PET)) in 50% cases. Single EMB session had a sensitivity of approximately 30% in detecting CS, but repeated biopsies or taking histologic samples from mediastinal lymph nodes markedly improved the diagnostic yield. In majority of cases, CS is a slowly progressive cardiomyopathy. With up-to-date diagnostic methods and treatment, 99% of patients were alive without cardiac death or transplantation at 1 year and 91% after 10 years from symptom onset. The most common presentations in GCM patients were heart failure and AV-block. Moreover, ventricular arrhythmias were common with two third of patients experiencing sustained ventricular tachycardia or ventricular fibrillation during the disease course. With current diagnostic methods and therapy with a combination of immunosuppressants, the transplant free survival was 69% at 1 year and 52% at 5 years. In conclusion, the detection rate of CS and GCM in Finland is increasing and the prognosis with contemporary diagnostic and therapeutic methods seems better than previously reported.
  • 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.
  • 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.
  • Saksi, Jani (Helsingin yliopisto, 2015)
    Carotid artery disease is a common cause of stroke, with approximately one in five ischemic strokes in the carotid artery distribution stemming from thromboembolisms caused by an unstable atherosclerotic carotid plaque (CP). Despite the fact that carotid atherosclerosis can lead to cerebrovascular complications, some patients afflicted by a high-grade carotid stenosis (>70%) remain asymptomatic. This divergence in clinical courses captures one of the most pressing questions in cardiovascular medicine: what are the key molecules and pathways decisive to local atheroma vulnerability and connected with disabling clinical outcomes? In the first paper, we utilized a genome-wide approach to screen for gene expression changes in stroke-associated CPs to identify genes and pathways related to atheroma vulnerability and symptom generation. This approach was successful in identifying several significant expression changes in novel genes and in genes already connected with atherosclerosis development, suggesting that the local atheroma-derived gene expression patterns are closely connected to the patient s clinical phenotype. A detailed data-driven approach, using three independent data pre-processing methods, identified fatty acid-binding protein 4 (FABP4) as the lead hit overexpressed in stroke-associated CPs, thus linking FABP4 and its transcriptional activity to atheroma vulnerability. Immunohistochemical analysis revealed the most prominent expression of FABP4 protein in the histological regions of atheroma vulnerability, coinciding with the abundance of lipid-laden macrophages and thus connecting the overexpression of FABP4 with lipid accumulation and inflammation within the CPs. In the second paper, we focused on the molecular mechanisms through which increased FABP4 expression could regulate atheroma vulnerability. As causality is difficult to infer from associative expression data we adapted a genetic approach searching for variants that could regulate the expression of FABP4. Using a naturally occurring low-expression variant (rs77878271) we were able to link genetically reduced atheroma expression of FABP4 to endoplasmic reticulum (ER) stress signaling, and the attenuation of apoptosis, with high expression contributing to increased lipid burden and inflammation. We discovered that the low-expression variant of FABP4 was associated with lower circulating total cholesterol levels, with the lowest levels in obese (body mass index, BMI ≥ 30) minor allele homozygotes. Furthermore, the variant allele carriers showed obesity-related reduction in subclinical markers of atherosclerosis, manifested as reduced carotid intima-media thickness (IMT) and lower prevalence of CPs. Most importantly, we found that the local atheroma effects of FABP4 penetrated to end point level, as the minor allele homozygotes showed 8-fold lower odds for myocardial infarction (MI) and enrichment of the variant in patients with clinically asymptomatic carotid artery disease. Obesity-related reduction of total cholesterol levels observed in the low-expression variant carriers pointed to a metabolic component mediated by genetically reduced FABP4 expression. Based on the discoveries made in FABP4-deficient mouse models, we hypothesized that genetically reduced FABP4 expression could lead to sustained enhancement of adipocentric de novo lipogenesis (DNL), which could in part explain the obesity-related phenotypes also in man. We found that the low-expression variant of FABP4 was associated with circulating markers of enhanced lipolysis and reduced circulating FABP4 protein levels. The variant allele carriers showed a propensity for higher BMI, with evidence for enhancement of DNL, improved beta-cell function, and reduced obesity-related type 2 diabetes (T2D) risk. These results imply that FABP4-regulated production of adipocyte-derived lipid signals during DNL in the low-expression variant carriers may in part lead to enhanced beta-cell function and reduced obesity-related T2D risk. In this thesis work, we identified FABP4 as a key molecule at the crossroads of metabolic and inflammatory responses, potentially involved in local atheroma vulnerability and connected with cardiometabolic outcomes. Most likely the role of FABP4 in atherosclerosis is multifaceted, converging with the passage of time within the artery atheroma, and culminating in the regulation of inflammatory responses affecting cell survival, acute plaque vulnerability and ultimately cardiovascular risk. These data implicate FABP4 as a potential pharmacological target for prevention of cardiometabolic complications connected with atherosclerosis and obesity.
  • Heikinheimo-Connell, Terttu (Helsingin yliopisto, 2015)
    Background: Stroke is the second most common cause of death. It is also the leading cause of disability worldwide. Low-income countries, where infectious diseases play a major role, carry the biggest burden of growing numbers of stroke. Infections can trigger an acute stroke. Malawi is situated in Sub-Saharan Africa, where prevalence of chronic diseases like high blood pressure, diabetes mellitus, and stroke are increasing. The HIV-prevalence among young adults is 12%. HIV may cause milder neurocognitive impairments, which are called HIV-associated neurocognitive disorders (HAND). Methods: The Helsinki Young Stroke Registry (HYSR) includes over 1000 patients aged 15-49 years with acute ischemic stroke. We investigated how high leukocyte count and infections affect recovery after stroke. In Malawi, we defined the stroke characteristics, impact of HIV, and one-year outcome. A selected subset of patients were interviewed about their quality of life (QOL). A group of Finnish men were investigated to determine whether HIV has caused neurological or neurocognitive impairment when with best available treatment for even 30 years. Results: In Helsinki (781 patients) high leukocyte count weakened 3-month outcome, however, not the long-term outcome (8.1±4.2 years). In the other study (681patients) 10% had preceding infection (PI), most commonly upper respiratory tract infection, and 15% had post stroke infection (PSI), most commonly pneumonia. All the infections worsened 3-month outcome. PSI was associated with long-term (7.8±4.0 years) higher risk of all-cause death. In Malawi (147 patients) HIV-infected patients (34%) suffered more often from ischemic stroke than HIV-negative patients. They were younger and had less often conventional risk factors for stroke. More than half of all patients had a poor outcome at 1-year, and the mortality rate was 45%. This was related to stroke severity and female gender but not to presence of HIV. We interviewed 25 patients. Good functional outcome was positively associated with better QOL on the domains of self-care and ability for communication. Females scored worse on the domains of fatigue and cognition. Older age was associated with worse QOL on the domain of self care. HIV did not affect the QOL. We evaluated 17 Finnish HIV-patients. A third had signs of polyneuropathy, half suffered from fatigue, and mild depression was common. Magnet resonance image (MRI) showed signs of lacunar ischemic stroke in three patients. Conclusions: The high leukocyte count in HYSR patients was associated with vascular disease and stroke severity. The high leukocyte count, PI and PSI were associated with poor short-term outcomes. PSIs were also associated with higher long-term mortality. In Malawi, severe stroke and gender were associated with unfavorable outcome. HIV-infection is common especially among young stroke patients, but not related to unfavorable outcome. QOL was associated with age, gender, and functional recovery. Despite HIV, the surviving Finnish patients had no describing features of HAND. Polyneuropathy, fatigue and mild depression were common. The silent strokes in MRI support the hypothesis of HIV increasing the risk of strokes.