Väitöskirjat

Recent Submissions

  • Kantokoski, Olga (Helsingin yliopisto, 2020)
    This doctoral dissertation examines the ‘politics’ of the EU's international police cooperation. The existing academic scholarship approaches the historical process of internationalization of the European internal security and law enforcement collaboration mainly from a ‘technocratic’ and ‘apolitical’ perspective, whereby ‘externalization’ of the Union's internal security objectives to the third countries and regions is explained in a ‘functionalist’ manner as a response to the ever growing menace of international organized crime. The ‘institutional factor’, or the presence of adequate anti-crime institutional resources and infrastructure, is additionally highlighted by scholars as an important enabler of the Union's international cooperation in the domain of internal security. By contrast, the causal role of the EU's high-level political and power considerations in the justice and home affairs’ internationalization process has remained insufficiently understood and theorized in the existing literature. This research project expands the theoretical horizons of both specialized literature on the EU's external JHA cooperation and a broader stream of research on the EU's foreign policy by exploring the Union's police cooperation as primarily reflective of the EU's evolving international political and power ambitions regarding its geographical neighbourhood. It thus challenges the prevalent view of the external dimension of JHA as being a merely security-driven, anti-crime practice, and a ‘functional corollary’ of the process of institutionalization of the EU's internal JHA landscape. Empirically, the dissertation engages with the examination of the recent history and practices of European internal security collaboration in the EU's core strategic neighbourhood of the Western Balkans: being perceived and securitized as a ‘stronghold’ of organized crime in the European discourse, this region has for years acted as a site of the Union's most intense international anti-crime activities. Chronologically, the research project spans the major period of 1991-2011, when the Western Balkans rose to prominence in the EU's foreign policy and cooperation on internal security matters and police cooperation with this region acquired particular importance for the Union. The dissertation project is of significance not only due to its empirical value (it is based on a significant amount of raw empirical data that the author processed into findings by methods such as interviews with people at the front-line of policy developments), but also because it opens up new theoretical-conceptual avenues to the study of the European Union as an international political actor.
  • Tikkanen, Lotta (Helsingin yliopisto, 2020)
    The aim of this doctoral dissertation was to gain a better understanding of the mechanisms regulating collective learning and burdening in school-development work. To reach this goal, the reform stakeholders’ perceptions of collective learning, burdening, and regulators of the reform, as well as reform implementation strategy and proactive strategies were explored. The participants were comprised of three stakeholder groups, who were responsible for school development at different levels of the educational system: 1) the administrative level (officials of the Finnish National Agency for Education), 2) the district level (members of the working groups responsible for the curriculum reform at the district level), and 3) the school level (school principals). In this dissertation, a mixed methods approach was adopted. Officials of the Finnish National Agency for Education (N = 23) were interviewed and they completed a survey. District-level stakeholders (N = 550) and school principals (N = 420) completed the surveys. The results indicated that administrative-level stakeholders identified reform regulators at every level of the educational system. The regulators varied in terms of type (i.e. structures and resources, collective, and individual factors) and function (i.e. hindering and promoting factors). The type and function of the regulators varied according to the level in which the regulators were identified. The results showed that administrative and district level stakeholders perceived that the school reform strategy supported the basic ideas of the top-down–bottom-up implementation approach, i.e. change management and knowledge sharing. The levels of burdening, in terms of reform-related stress and burnout symptoms, were moderate, among district and school level stakeholders. In addition, they actively utilised proactive strategies to regulate the burdening. However, the variation between the individuals in both experienced burdening and the use of proactive strategies was quite high. The results showed that the top-down–bottom-up reform implementation strategy was related to perceived school impact in terms of enhancing the opportunities for collective, cumulative learning in school reform work. At the same time, knowledge sharing was related to lower levels of reform-related stress and increased use of proactive strategies. Accordingly, the utilisation of proactive strategies was related to lower levels of reform-related stress and higher levels of perceived school impact. This doctoral dissertation contributes to the literature on school development by a) shedding light on how learning and wellbeing are related to each other in school reform, b) providing new insights on how reform implementation strategy can simultaneously enhance collective learning and buffer burdening, c) utilising mixed methods and a systemic approach in exploring a large-scale school reform, d) providing deeper understanding on the anatomy of educational practitioners’ burdening by combining variable- and person-centred approaches. Keywords: burdening, burnout, curriculum reform, proactive strategies, reform implementation strategy, school development, work stress
  • Hautakangas, Sami (Helsingin yliopisto, 2020)
    The main theme in this dissertation is to determine the means of achieving the Baltic Sea Action Plan targets, with an emphasis on municipal wastewaters. Thus, the nitrogen and phosphorus reduction potentials of wastewater treatment plants and costs of nutrient reductions are calculated. The nutrient reduction potential is huge for municipal wastewater. Furthermore, abating nutrients in wastewater treatment plants is cheaper than previously thought. In particular, phosphorus abatement costs are much lower than those in agriculture. A numerical model is built to demonstrate that a considerable share of the targets of the Baltic Sea Action Plan can be met by nutrient abatement in wastewater treatment plants. Moreover, it is shown that with properly designed initial allocations, a nutrient trading scheme can even out the cost burden between wastewater treatment plants. However, transaction costs may play a significant role in nutrient trading in the Baltic Sea region. With an analytical model, it is demonstrated that if a water utility has market power, a tightening nutrient policy may decrease the price of potable water but increase the wastewater tariff. Based on the analytical model, a numerical model is built to illustrate that households connected to small water utilities face higher prices and higher price increases associated with environmental protection measures than do households connected to large water utilities. Finally, it is shown when the level of nutrient abatement reaches the upper limit, the costs water utilities face no longer depend on the instrument applied.
  • Mononen, Niina (Helsingin yliopisto, 2020)
    Medicines information (MI) is an essential part of rational pharmacotherapy. Intensified clinical research and more matured pharmacovigilance systems have produced more information on therapeutic effects of pharmacotherapies to facilitate more detailed profiling of their benefits and risks. In turn, more open communication on medications with patients has been facilitated by drug safety issues, patients’ right to know about their treatments and by a significant increase in electronic information sources. Even though a wide variety of evidence-based MI sources for patients and consumers is currently available, the coordination between MI sources and their providers has been limited. The need for coordination has become more evident as the number of MI sources and providers has substantially increased over time. Improved communication on medicines to patients and consumers has been a strategic priority in developing MI practices in the European Union, including Finland, during the 2000s. To enhance the coordination of MI practices in Finland, the Finnish Medicines Agency Fimea published the first national MI strategy in 2012. The primary goal of the national MI strategy is to influence MI practices in all social and healthcare settings to reach the ultimate goal of well-informed patients who adhere to their medication. This thesis examines MI practices and policies in Finland during the 2000s. The primary goal of the thesis is to support the strategic development of MI and the implementation of the national MI strategy. The thesis comprises three independent studies (I–III) in which both quantitative and qualitative research methods were applied. They investigated development targets for MI practices in Finland based on a systematic review of the existing literature (I), assessed long-term trends in the receipt of MI among the Finnish adults (II), and evaluated how well the ultimate goal of the national MI strategy regarding well-informed adherent patients with chronic diseases had been achieved at the midpoint of the strategy period in 2015 (III). The systematic review on MI research conducted in Finland during 2000–2016 found 126 studies that covered a wide range of approaches applying various research methods (Study I). More than half of the studies were qualitative (54% of all studies, n=68), although surveys were the most commonly used individual method (47%, n=59). Twelve studies were interventions and only six studies applied a theory. Patient counselling in community pharmacies was the most commonly studied topic (19%, n=24). Regardless of some methodological pitfalls, MI research provides a multifaceted understanding of MI practices and their development needs in Finland. Research should shift towards larger research lines having a stronger theory base and study designs. Future research should be focused on the effectiveness of MI in different healthcare settings, along with the use of electronic MI sources and services, MI literacy, MI needs among patients and healthcare professionals (HCPs). Based on the nationally representative repeated postal survey “Health Behaviour and Health among the Finnish Adult Population” conducted by the National Institute for Health and Welfare during 1999–2014, physicians, community pharmacists and package leaflets were the main MI sources among adult medicine users aged 15–64 years (n=18862) throughout the study period (Study II). The use of the Internet as a MI source increased the most noticeably, being used by 1% of the adult medicine users in 1999 and 16% in 2014. The number of medicine users who did not receive MI from HCPs more than doubled (17% to 38%), and the number of medicine users who did not receive MI from any sources increased by sevenfold (4% to 28%) during the study period. It is necessary to continue research on trends in the receipt of MI at the population level and to identify population groups requiring special attention, such as senior citizens with multiple medications. Further evidence is also needed on factors contributing to a growing number of medicine users not receiving MI. According to the interviews among stakeholder representatives (n=79, 71%) involved in the implementation of the national MI strategy, the medication use processes for patients with chronic diseases requires development at every level of implementation (i.e., macro, meso, micro) (Study III). Medication counselling and other care advice by HCPs, particularly by community pharmacists, were the best implemented actions in general. The major actions needing development at the infrastructure level (macro) concern the coordination of care, transfer of patient information between care units, lack of reconciled medication lists, and local and national agreements on the responsibilities of patients and HCPs involved in the medication use process; at the HCP level (meso), focus on implementing the entire medication use process in primary and social care, particularly in geriatric units; and at patient level (micro), related to limited patient involvement in their care, lack of patients’ adherence to treatment and the inability of patients to retrieve information. Patients need to be better involved in implementing their treatment by improving empowerment and partnership to achieve the goal of well-informed adherent patients. KEYWORDS Medicines information, medicine user, patient, strategy, Finland
  • Salo, Veijo (Helsingin yliopisto, 2020)
    Cells store excess energy mostly as neutral lipids (NLs), inside fat-specialized organelles called lipid droplets (LDs). LDs are metabolic hubs involved in many cellular processes, such as lipid metabolism and endoplasmic reticulum (ER) homeostasis. There is increasing evidence linking LDs and human pathologies, including e.g. cardiovascular and fatty liver disease. Thus, detailed understanding of LD biology should be beneficial for tackling these disease states. LDs consist of a core of NLs surrounded by a phospholipid monolayer. Their biogenesis begins in the ER, with accumulation of NL lenses within the ER bilayer. These lenses subsequently grow and bud into the cytosol. All this likely occurs in specialized ER subdomains, but a detailed understanding of the earliest steps of LD biogenesis is still lacking. After formation, LDs retain an intimate relationship with the ER, through ER-LD contacts. Seipin is an oligomeric ER transmembrane protein implicated in LD assembly and adipocyte development. Mutations in seipin give rise to three disease states: a severe form of congenital lipodystrophy (BSCL2), a motor neuron disease called seipinopathy and a fatal neurodegenerative disease called Celia’s encephalopathy. The molecular function of seipin is unclear. In this thesis, using advanced cell biological techniques, we sought to expand the understanding of the function of seipin and how mutations in seipin lead to human disease. In the first study, we focused on the seipinopathy-linked seipin mutant, N88S-seipin, which is known to form misfolded aggregates. We found that overexpression of N88S-seipin leads to ER stress, decreased NL storage and voluntary swimming in zebrafish larvae. Upon increasing NL stores, these defects were alleviated, and the mutant protein was translocated from the ER to regions flanking LDs. Increasing cellular LDs also alleviated ER stress induced by tunicamycin. We propose that increasing LDs may aid cells in coping with misfolded proteins. We next focused on deciphering the function of seipin in LD formation and ER-LD contacts. Endogenously tagged seipin localized stably at ER-LD contact sites, but a BSCL2-linked mutant did not. Knockout (KO) of seipin led to the formation of numerous tiny LDs, which failed to grow and recruit protein and lipid cargo from the ER. Furthermore, whilst all LDs in control cells were connected to the ER, seipin KO lead to a subset of LDs completely detaching from the ER. The remaining LDs of seipin KO cells also had morphologically aberrant and dysfunctional ER-LD contacts. As similar defects were also evident in BSCL2 patient fibroblasts, we propose that seipin is crucial for the formation of ER-LD contacts and cargo delivery. Finally, we found that seipin can determine the site where LDs start to form, as relocalization of seipin to a subdomain of the ER, the nuclear envelope, was sufficient to relocalize LD biogenesis to that site. We found that seipin-mediated ER-LD contact sites display a uniform neck-like architecture, suggesting that the seipin oligomer may structurally restrain this site. Seipin was also required for ER-LD contact maintenance, as acute removal of seipin from ER-LD contacts lead to strikingly heterogonous LD growth. This LD growth heterogeneity arises via a biophysical ripening process, with NLs partitioning from smaller to larger LDs via LD-ER contacts. These data suggest seipin-mediated ER-LD contacts function as a valve facilitating NL flux from the ER to LDs, thus allowing controlled LD growth. Overall, this thesis provides insight into the function of seipin and mechanisms of LD formation. Our data suggest that the ER-LD nexus could be considered as a joint system, with continuous bidirectional trafficking of cargo occurring via ER-LD contacts mediated by seipin. Future work will be required to investigate the molecular intricacies of the lipid flux occurring at ER-LD contacts. A deeper understanding of LD biology will aid in the development of new therapeutics for a number of pathologies, including seipin-related disorders and common metabolic disturbances.
  • Wang, Yilin (Helsingin yliopisto, 2020)
    Microbial infections share many symptoms in common, rendering diagnosis difficult solely on clinical grounds. Thus, rapid, cost-effective and reliable tests are necessary for the diagnosis of infectious diseases. While the traditional diagnosis is mostly confined to detection of one pathogen at a time, a multiplex array could be a feasible alternative to improve the efficiency in the detection of infections. The Luminex xMAP-based high-throughput platform can provide simultaneous analysis of multiple analytes from the same sample by utilising differentially dyed microspheres. In this thesis, I developed xMAP-based Suspension Immuno Assays (SIAs) for the determination of IgG antibodies, IgM antibodies, as well as the avidity of IgG against the human cytomegalovirus (HCMV), Toxoplasma gondii (T. gondii) or human parvovirus B19 (B19V). Moreover, I also developed xMAP-based multiplex DNA assays for 13 human polyomaviruses (HPyVs). Primary infections by HCMV, T. gondii and B19V during pregnancy can result in severe consequences to the foetus. The serological status of the mother is critically important in counselling and recognition of infections. Hereby, I developed and evaluated SIAs for IgG, IgM and IgG-avidity against these three important pathogens. Diagnostic performances of the new assays were assessed with more than 1000 well-characterised serum samples. All the newly developed assays exhibited excellent performance compared to corresponding high-quality reference methods. The positive and negative percent agreements of the antibody-SIAs in comparison with high-standard reference assays were 92-100% and 95-100%, respectively. Kappa efficiencies between SIAs and corresponding reference assays were 0.94-1. Intra-assay and inter-assay coefficients of variations ranged between 2-12% and 1-19%, respectively. Among clinical samples from individuals with primary infection, the IgM- and IgG-SIAs served as highly sensitive screening means for detection of acute infections and immune status; and IgG-avidity-SIAs as a highly specific confirmatory approach for separation of primary infections from long-term B-cell immunity. On the other hand, during the past 12 years, a dozen viruses have joined the known family members of HPyVs. Serological studies have shown that HPyV infections occur at young age and most of the viruses circulate widely in the general population. Although HPyV infections are generally asymptomatic, severe complications can arise due to virus reactivations in immunocompromised or elderly individuals. HPyVs can persist lifelong after primary infection; however, their tissue specificities, persistence sites and transmission routes are still unclear. Also, the clinical manifestations of HPyVs with regard to immune suppression are largely unidentified. To this end, I developed xMAP-based multiplex DNA assays for all 13 HPyVs known before 2017, by using primer pairs and probes targeting the respective HPyV major capsid protein VP1 genes. The xMAP-based multiplex assays allowed for simultaneous detection of all the HPyVs with detection limits of 1-100 copies/µl. At high copies (105 copies/µl) each of the 13 target sequences were identified correctly with no cross-reactions. With this novel and specific assay, the extent to which the lymphoid system plays a role in the HPyV infection and persistence was assessed. The frequency of occurrence of HPyV viral genomes was explored in 78 lymphoid tissues from children and adults with tonsillar diseases. HPyV-DNA was found in 17.9% (14/78) of tonsils: JC polyomavirus (JCPyV, n=1), WU polyomavirus (WUPyV, n=3), Merkel cell polyomavirus (MCPyV, n=1), human polyomavirus 6 (HPyV6, n=6), trichodysplasia spinulosa polyomavirus (TSPyV, n=3). The observed frequent occurrence of HPyVs in human tonsils suggests the lymphoid tissue plays an important role as a potential transmission route and a location of persistence for these viruses. However, whether or not the undetected HPyVs share the same infection route requires more investigation with different sample types. Furthermore, to determine the occurrences in skin and clinical associations of HPyVs, I studied their genoprevalences in biopsies of premalignant [squamous cell carcinoma in situ (SCCis) or actinic keratosis (AK)] lesional vs. benign skin from 126 liver transplant recipients (LiTRs); as well as in healthy skin of 80 immunocompetent adults. Multiplex screening was followed by singleplex qPCRs of positive samples, for reference and quantification of the viral DNAs. In total, five dermal HPyVs – MCPyV, HPyV6, human polyomavirus 7, TSPyV, and Lyon IARC polyomavirus (LIPyV) – were found in 26.2% (58/221) skin biopsies. The prevalences and quantities of MCPyV in premalignant vs. benign skin of LiTRs were similar to those in healthy skin of controls. TSPyV was found in a single skin lesion at very low copies. The other three HPyVs occurred exclusively in benign skin. Overall, in 10 out of 12 SCCis/AK patients the viral DNA findings in skin were alike. Thereby, the occurrences of HPyVs in the skin of LiTRs and controls speak against a role for any of HPyVs in SCC development. The work presented in this thesis shows that the xMAP-based serological approaches exhibit excellent diagnostic performances compared to corresponding conventional methods. Moreover, the developed xMAP-based multiplex PCR for 13 HPyVs could be applied successfully in a variety of clinical materials. Altogether, the newly developed systems provide a powerful tool for medical diagnosis and research.
  • Sullanmaa, Jenni (Helsingin yliopisto, 2020)
    This dissertation presents an exploration of the anatomy and function of curriculum coherence as perceived by educational stakeholders in national core curriculum reform in basic education. It presents analysis of how educational stakeholders from three levels of the educational system experienced the core curriculum’s coherence, and whether there were differences within and between the levels. In addition, the study included an examination of whether curriculum coherence is connected to the impact of the reform process on school-level development. The dissertation is comprised of three independent part studies. The study was conducted with quantitative methods, combining variable-centered and person-centered analyses. Survey data were collected from three cohorts: state-level stakeholders involved in core curriculum development (N = 116), district-level stakeholders involved in local curriculum development (N = 550) and comprehensive school teachers at two time points in the early stages of implementing the curriculum in schools (N = 901). The results showed that perceived curriculum coherence consisted of: 1) consistency of the intended direction, 2) an integrative approach to teaching and learning, and 3) alignment between objectives, content and assessment (study I). Overall, the state-level stakeholders seemed to have the highest perceptions of the core curriculum’s coherence and teachers the lowest. While all participant cohorts perceived the core curriculum to be rather coherent, the consistency of the curriculum’s intended direction was seen as the least successful element of coherence. The person-centered analyses provided more detailed information about the variation in perceived curriculum coherence within and between the levels of the educational system. Two distinctive profiles were identified among state- and district-level stakeholders in study II. Stakeholders in the high coherence and impact profile (83%) experienced the core curriculum to be coherent in terms of all three elements and expected the reform process to have positive impact on school-level development work. In turn, stakeholders in the lower consistency of the intended direction and impact profile (17%) perceived the consistency of the intended direction to be lower, combined with less positive expectations of the school-level impact. State-level stakeholders had higher odds of belonging to the high coherence and impact profile compared to the district-level stakeholders. In study III, five profiles were identified based on teachers’ perceived curriculum coherence at two time points during the early stage of curriculum implementation. Teachers in the largest profiles, high (21%) and high-moderate coherence (48%), experienced the core curriculum to be coherent, however their perceived coherence slightly decreased during the one-year follow-up. In turn, teachers in the low-moderate (20%) and low coherence (3%) profiles perceived the core curriculum to be less coherent at first but their perceptions slightly increased after the first year of implementation. Finally, the decreasing coherence (9%) profile had rather low initial perceived coherence and showed a large drop during the follow-up. The results also showed that district-level stakeholders’ perceptions of the core curriculum’s coherence were strongly connected to their expectations of the reform’s impact on functional school development (study I). Moreover, teachers’ curriculum coherence profiles differed in terms of their perceptions of the school impact: the more coherent teachers perceived the core curriculum, the more positive they considered the impact of the reform to be on school-level development work (study III). The dissertation contributes to the research on curriculum reform by a) exploring the anatomy of curriculum coherence as perceived by educational stakeholders, b) showing that curriculum coherence is connected to the potential of the reform to support locally functional school development, c) providing a systemic inquiry of perceived curriculum coherence at various levels of the educational system in the context of large-scale curriculum reform, and d) utilizing both variable-centered and person-centered analytical approaches to gain more detailed information on perceived curriculum coherence throughout the system. ________________________________________ Keywords: curriculum coherence, curriculum reform, Finnish comprehensive school, school development
  • Porkka, Noora (Helsingin yliopisto, 2020)
    Lynch syndrome is the most prevalent cancer predisposition syndrome that causes significantly increased lifetime risk of cancer in multiple organs such as colorectum, endometrium and ovarium. The predisposition is caused by germline mutations in DNA mismatch repair (MRR) genes MLH1, MSH2, MSH6, and PMS2. Lynch-like syndrome colorectal tumors, like Lynch syndrome tumors, are MMR-deficient. Nevertheless, Lynch-like syndrome tumors do not bear germline mutations in MMR genes nor methylation of the promoter regions of MMR genes that would explain the deficiency. Instead, MMR deficiency in majority of Lynch-like syndrome tumors is caused by two somatic mutations in the MMR genes. Dysfunctional MMR protein complex enables accumulation of mutations in the genome (mutator phenotype) and, eventually, microsatellite instability and cancer. The reasons behind organ selectivity in MMR-deficient tumors are unknown, and whether breast cancer is part of the Lynch syndrome spectrum is under debate. The germline mutations in MMR genes are well studied, but molecular characteristics of Lynch syndrome tumors remain to be studied further. Lynch-like syndrome tumors remain less well characterized: besides the double somatic MMR mutations as a cause of MMR deficiency, their molecular and clinicopathological features as well as their incidence in the population remain poorly known. Currently, the only possibility to diagnose Lynch-like syndrome is by ruling out the possibility of germline mutations in MMR genes (Lynch syndrome) or methylation of the promoter regions of MMR genes. Synchronous ovarian and endometrial carcinomas are common in Lynch syndrome; whether they are of same origin (metastatic cancer) or two independently developed primary cancers remains to be resolved. We aimed to characterize the epigenetic and somatic mutation profiles in Lynch syndrome representing colorectal, ovarian, endometrial and breast carcinomas, and to identify new unique features that could be used in evaluating cancer risk, diagnosis and targeted treatment. We used targeted high-throughput sequencing of 578 known cancer genes to investigate the somatic mutation profiles, and methylation-specific multiplex ligation-dependent probe amplification to study the epigenetic profiles of the tumors. Non-synonymous somatic mutations were detected from sequencing data of the paired tumor and normal tissues to determine mutation signatures and identify potential driver genes. The data was also compared statistically between tumors of different origin, epigenetic status, and between breast carcinomas from Lynch syndrome mutation carriers and their known non-carrier family members. We observed that Lynch- and Lynch-like syndrome tumors have unique somatic mutation and methylation profiles. We were able to link the methylator phenotype to high somatic mutation rates, and Lynch-like colorectal tumors to hypermethylated CpG island methylator phenotype (CIMP), which are novel findings. Our discovery of high mutation burden in genes associated with epigenetic regulation provides a new link between genetic and epigenetic factors in tumorigenesis. Genetic and epigenetic characterization of synchronous ovarian and endometrial carcinomas indicated shared origin, in analogy to sporadic cases. Molecular characteristics and especially mutational signatures of breast tumors of Lynch syndrome mutation carriers indicated that breast carcinoma is likely to be part of the Lynch syndrome tumor spectrum. These findings bear potential clinical relevance since the molecular tumor profiles may be used in diagnosis and may guide tailored management of the patients. Many of the mutated genes are part of signaling routes to which targeted molecules either exist or can be developed.
  • Korhonen, Suvi (Helsingin yliopisto, 2020)
    Chlamydia trachomatis is a common cause of sexually transmitted infections (STI), which can lead to pelvic inflammatory disease (PID) and reproductive complications. C. trachomatis genotypes D–K cause urogenital infections and genotypes L1–L3 cause lymphogranuloma venereum (LGV). LGV infection outbreaks were reported in 2003 in Europe after decades among men who have sex with men (MSM). A new variant of C. trachomatis (nvCT) was identified in Sweden in 2006 with a large deletion in the plasmid leading to failing detection by two nucleic acid amplification tests (NAAT). Other microbes causing genitourinary tract infections, such as the human papillomavirus (HPV), herpes simplex virus (HSV), Mycoplasma genitalium and human herpesvirus 6 (HHV-6) may also contribute to the epidemiology of C. trachomatis. C. trachomatis promotes its survival inside the host cell through secreted effector proteins. The transcriptional expression of the genes encoding these effectors has mainly been studied using C. trachomatis reference strains propagated in cultured cells and not with currently circulating strains. In this thesis, the C. trachomatis genotype distribution and the occurrence of the Swedish nvCT in Finland was studied with real-time polymerase chain reaction (PCR) in urogenital specimens. The three most prevalent C. trachomatis genotypes were E, F, and G. The percentage of infections due to genotypes F and G increased slightly in 1987–2008, but otherwise the proportion of genotypes has remained quite stable in Finland during the last ten years. The Swedish nvCT was rare in Finland, as only two specimens (0.4%) containing the variant plasmid were detected. The prevalence of the LGV types in extragenital specimens in Finland was investigated with real-time PCR. Among the C. trachomatis positive samples, nine samples (8%) contained LGV types and one sample (1%) contained both non-LGV and LGV types. The LGV types were detected mainly in rectal swabs. Altogether nine LGV positive patients were identified and they were all MSM, and all except one were human immunodeficiency virus (HIV) positive. LGV infections among MSM also occur in Finland, which should be taken into account when considering the management of rectal C. trachomatis infections. The prevalence of HSV, HHV-6, HPV and M. genitalium in urogenital samples of C. trachomatis NAAT positive and negative young women in Finland was analysed with real-time PCR. The prevalence of HPV was significantly higher among the C. trachomatis positives than the negatives (66% vs. 25%). The prevalence of HSV, HHV-6, and M. genitalium was not significantly different between the C. trachomatis positives and negatives or between those who cleared the C. trachomatis infection and those who did not. The high prevalence of HPV among the C. trachomatis positives suggests greater sexual activity and increased risk for sexually transmitted pathogens. Low-passage-number C. trachomatis clinical isolates originating from cervical swabs and reference strains were used to study the expression of C. trachomatis protease (cpaf), phosphoprotein (tarp) and cytotoxin (tox) genes in a cell line during the chlamydial developmental cycle with real-time reverse transcriptase PCR (RT-PCR). Dissimilarities were observed in the gene expression patterns of cpaf and tox between the clinical isolates and the reference strains. All the strains had a similar tarp expression profile. Most clinical isolates showed slower growth kinetics compared to the reference strains. The use of low-passage-number C. trachomatis clinical isolates instead of reference strains in the gene expression studies might better reflect the situation during human infection.
  • Jousi, Milla (Helsingin yliopisto, 2020)
    Background Clinical decisions in prehospital critical care are often based on limited information about the patient’s medical history and the events preceding the acute illness. In addition to physical examination, point-of-care (POC) laboratory diagnostics can provide information for decision-making. Unfortunately, obtaining blood samples for POC analysis from critically ill patients can sometimes be difficult, thus diminishing the usefulness of POC analyses in prehospital critical care. Intraosseous (IO) access is used as an optional vascular route for fluid and medication administration for emergency patients when difficulties with venous access are encountered. Using IO access as a source of POC laboratory samples is interesting; however, evidence regarding the feasibility and agreement of these samples with arterial and venous samples is scarce. We therefore designed a series of studies to obtain more information on the POC analysis of IO samples. Materials and methods First, we performed a systematic literature review of the studies addressing the POC analyses of IO samples (Study I). We included all publications using POC or conventional laboratory methods to compare IO samples with venous or arterial samples for the parameters relevant to emergency care. Second, we performed an observational study within 31 healthy volunteers (Study II). We evaluated the feasibility of IO analyses with an i-STAT® POC device and the agreement of IO values with arterial and venous values. The agreement was evaluated using the Bland–Altman method. In addition, we examined the necessity to draw waste blood before taking the actual IO sample for POC analysis. Third, we studied the usability of IO POC values under unstable haemodynamic conditions with an experimental porcine (n = 23) resuscitation model (Study III). The model simulated a real-life course of cardiac arrest (CA) and cardiopulmonary resuscitation (CPR). Four repeated samples were simultaneously drawn from the IO access, artery and central vein during CA and CPR, and were instantly analysed with an i-STAT® POC device. The laboratory values were plotted as a function of time to demonstrate their development during CA and CPR. The arterial, venous and IO samples which were taken during CPR were compared with the arterial baseline samples to observe how they resemble the pre-arrest state. Last, in an observational study, we analysed the agreement between IO and arterial samples obtained from 35 critically ill prehospital patients, using the Bland–Altman method (Study IV). Moreover, we administered a questionnaire about acceptable biases in clinical practice to 16 experienced emergency physicians and compared our results with their responses. Results The 27 reviewed studies had heterogeneous populations: healthy volunteers, haemodynamically stable and unstable animals, adult and paediatric haematologic patients, and emergency patients. Only three of these studies followed the recommended guidelines for method comparison studies. The sample sizes were relatively small (n = 14–20) and the populations were heterogeneous in these three studies precluding the combining of results for meta-analysis. However, in IO samples, potassium values were generally higher than in arterial or venous samples. In the observational studies, we found that the POC analyses of IO samples were often feasible. Higher failure rates were associated with higher age. Agreement of IO values with arterial values appeared acceptable for base excess, pH, standard bicarbonate, lactate, glucose, ionised calcium and sodium within healthy volunteers and critically ill emergency patients. Potassium values from IO samples were systematically higher than arterial and venous values (biases 1.8–2.2 mmol/l). Agreement within haemoglobin and haematocrit measurements showed very large variety (95% limits of agreement in the bias of haemoglobin up to 95 g/l). However, the sample sizes were too small to unequivocally prove the agreement. Using the resuscitation model, we discovered that IO, arterial and venous values changed differently from one another during CA and CPR. Acidaemia was detectable in IO samples during untreated ventricular fibrillation, but in arterial samples the acidaemia was evident only after the initiation of CPR. The average potassium values during CPR from IO, arterial and venous samples were 4.4, 3.3, and 2.8 mmol/l higher than the pre-arrest arterial values, respectively. Conclusions When obtaining vascular access is challenging, IO access can be used for emergency POC analyses; however, the results of IO POC analyses should be interpreted with care. Waste blood does not need to be taken before the sample. POC analyses of IO samples may fail for older patients. In general, potassium values from IO samples are usually higher than those from arterial and venous samples, haemoglobin and haematocrit measurements from IO access are not reliable, and partial pressure measurements of oxygen and carbon dioxide from IO samples represent venous rather than arterial values.
  • Deng, Biar (Helsingin yliopisto, 2020)
    Rainfed agriculture is a vital land use practice for food security and economic development in most of drylands, but particularly in sub-Saharan Africa (SSA). However, it is becoming an increasingly uncertain and inefficient practice in SSA because of climate change and extremes (i.e. low and erratic rainfall, high temperatures, floods, and drought occurrence), and low soil fertility and water supply. For example, yields of sorghum, which is the main staple food crop in South Sudan, are dwindling under rainfed cultivation in its main production areas in the north of the country due to the previously mentioned factors. Nevertheless, soil amendment materials, such as biochars, along with integration of sorghum production into agroforestry systems, which can improve soil fertility and water storage capacity, could assist in improving the crop yields. In this dissertation, the effects of Acacia seyal-based agroforestry and addition of biochar on soil water retention and supply and on sorghum yields were examined. The research focused on 1) the potential of using biochar as a soil amendment combined with A. seyal-based agroforestry in a field experiment, 2) the effect of biochar on alleviating water stress on sorghum yield in greenhouse conditions, and 3) simulation of the potential effect of biochar amendments on improving sorghum biomass and grain yield, especially as indicated by differences in yield between wet and dry years. The two-year agroforestry field experiment (Paper I) was carried out at Magara Village north of Renk in South Sudan, during the growing seasons of 2011 and 2012. The split block experiment included three A. seyal tree density treatments: no trees; scattered trees (100 trees ha-1) and dense trees (400 trees ha-1) and two biochar amendment treatments (0 t ha-1 and 10 t ha-1). The soil consisted of silty loam underlain by clay, and the biochar source was A. seyal trees. A soil analysis showed that agroforestry resulted in lower soil pH, N, and total and exchangeable Ca2+ contents and higher C/N ratios compared to sole sorghum cultivation. The application of biochar significantly increased the soil C and exchangeable K+ contents as well as the pedotransfer-derived field capacity and plant available water contents, but significantly decreased the content of exchangeable Ca2+ and cation exchange capacity. The inclusion of A. seyal trees significantly decreased the sorghum grain yields, and the effect of biochar on grain yield compared to sole sorghum cultivation without amendment was not significant. The Land Equivalent Ratio (LER, the sum of the fractions of the intercropped yields divided by the sole-crop yields) value was 0.3 for dense A. seyal intercropping combined with biochar in both 2011 and 2012 and with scattered A. seyal intercropping in 2011, but it was twofold greater (0.6) in 2012 with biochar amendment. The greenhouse experiment (Paper II) was carried out at the Viikki Campus, Helsinki, Finland, during May–December 2011. The main factor was drought stress with three levels of soil moisture content: 60% of field capacity (well-watered), 40% (medium drought) and 20% (severe drought). The same type A. seyal biochar, in the same amounts as applied in the field experiment (0 t ha-1 and 10 t ha-1), was used. Drought stress had a significant effect on sorghum gas exchange but not on sorghum stomatal traits. The stomatal conductance and photosynthesis and transpiration rates were all significantly reduced under severe drought compared to values found in plants that were under medium drought or well-watered. The photosynthetic water use efficiency (WUE) increased with the level of drought stress. Drought stress significantly reduced the sorghum biomass and grain yields compared to those observed in well-watered plants. Biochar addition did not have a significant effect on any of sorghum stomatal traits, gas exchange or grain yield. The biochar/sorghum simulation study (Paper III) was carried out using the water-driven crop-growth model AquaCrop (version 6.1). The model was parameterized for the field experiment site and soil conditions. Soil fertility stress parameters were adjusted so that simulated biomass and grain yield values best matched the levels recorded in the field experiment. Climate data for 2011 and 2012, both wet years, and for 1990, an extremely dry year, were extracted from the Climate Forecast System Reanalysis (CFRS) online dataset. The effects of biochar were simulated using the changes in soil hydraulic properties (increases in field capacity, available water capacity and saturated conductivity) reported in a published meta-analysis study. Generally, the simulated biochar amendments having the greatest effect on soil hydraulic properties increased the water content of the rooting depth in all three years, but an increase in sorghum production was only discernible for 1990. The results from paper I showed that sorghum yields are lowered when the crop is grown in agroforestry systems. As sorghum is not tolerant of shade, the reduction in sorghum production with increasing tree density was probably due to canopy cover and shading. This effect thus overrode any benefit of having the trees in the cultivation system. The results from paper II indicated that biochar has no significant effect on alleviating drought stress on sorghum production and grain yields, while the results from paper III showed biochar, while improving soil hydraulic properties, only resulted in increased sorghum biomass production and grain yield in very dry years. Overall, the results from this study showed that the propounded benefits of agroforestry and biochar need further study and critical assessment, particularly in semi-arid environments where the water supply through rainfall is low and erratic but the water demand is constantly high. The results may well vary with different crops and agroforestry systems, as well as with different soil types and the type and dose of biochar. Furthermore, the results may only become apparent with sufficient time and therefore long-term studies are needed.
  • Hemmilä, Marja (Helsingin yliopisto, 2020)
    Atmospheric aerosol particles are small, liquid or solid pieces that are floating in the air. They have a significant effect on air quality, human health and cloud formation. Sources of aerosols can be either primary or secondary, meaning that they can directly be emitted from the source to the air (e.g. sea salt, sand or pollen) or they can be formed from the precursor gases in the air. For example, sulphuric acid, ammonia, amines and oxidised organic vapours are gases that affect the nucleation process. Biogenic Volatile Organic Compounds (VOCs) are gases that are emitted by e.g. boreal forest, and they affect secondary organic aerosol (SOA) population by contributing to the production of oxidised organic vapours that participate in the formation and growth of secondary aerosol particles. In this thesis, thermal desorption inlet gas chromatograph coupled with mass spectrometer (TD-GC-MS) was used to determine how monoterpenes, which are one sub-group of the BVOCs, are emitted from Scots pine and Norway spruce trees. It was discovered that individual trees emit different amounts of various monoterpenes, even when the trees belong to the same species. We concluded that the emissions depend on the chemotype of the trees, which is an inherited property of the individual tree. Nitrogen containing gases, such as ammonia, amines and nitric acid can also take part in the aerosol formation and growth processes. Ammonia and amines stabilise sulphuric acid clusters, therefore helping the new aerosol particles to form. Another nitrogen contain gas, HONO, strongly affects atmospheric chemistry because it reacts with solar radiation and forms a OH• radical, which is one of the main radicals in the atmosphere. We measured the seasonal and diurnal variation of ammonia, nitric acid and HONO in the boreal forest with an instrument of Measuring AeRosols and Gases in Ambient air (MARGA), which is an online ion chromatograph with a sampling system. In this thesis, I developed a method for measuring aliphatic amines from the boreal forest air. I also coupled MARGA with a mass spectrometer (MARGA-MS) and used it to measure amine concentrations from the boreal forest air, observing the seasonal and diurnal variation of atmospheric amines. While I was measuring the atmospheric concentrations, the idea that amines could be emitted from the boreal forest floor and also melting snow and thawing ground, was born. To test this hypothesis, I measured with the MARGA-MS connected to a dynamic flow through chamber emissions from the boreal forest floor. I found that the boreal forest floor is indeed a source of amines.
  • Niinikoski, Laura (Helsingin yliopisto, 2020)
    Background: The aim of the thesis is to assess different surgical and biopsy techniques, which can help to treat breast cancer patients with less invasive methods. Material and methods: The thesis comprises four original retrospective studies. All study patients were treated at the Breast Surgery Unit of Helsinki University Hospital 2010-2016. Study I evaluated the feasibility of Breast Lesion Excision System (BLES) procedure in the treatment of breast lesions (n=80) with a needle biopsy –based suspicion of an intraductal papilloma. In studies II and III 1800 breast cancer patients underwent breast conserving surgery (BCS). Study II compared reoperations due to insufficient surgical margins and local recurrences (LR) after conventional or oncoplastic BCS and study III after BCS using radioguided occult lesion localization (ROLL) or radioactive seed localization (RSL). In study IV patients (n=507) with primary invasive breast cancer and axillary nodal metastasis preoperatively diagnosed by ultrasound (US)-guided needle biopsy underwent breast surgery and axillary lymph node dissection. The aim was to determine which factors were related to high nodal tumour burden in clinically node-positive breast cancer patients and to construct a predictive tool for evaluating the patient-specific risk of having >2 axillary lymph node metastases (LNM). Results: In study I, the BLES biopsy diagnosis was a benign intraductal papilloma or other benign in 61 lesions, 10 lesions were upgraded to high-risk tumours and five to malignancy. Four procedures failed, no major complications occurred. In study II, 1189 patients underwent conventional BCS and 611 oncoplastic BCS. Patients with oncoplastic BCS were younger, they had more often multifocal, larger and more aggressive tumours. There was no difference, however, in reoperation rates or in local recurrence-free survival (LRFS) between the groups during the follow-up. In study III, 318 patients underwent ROLL and 426 RSL. The reoperation rate or the 5-year LRFS was not different between these groups. In study IV, 153 patients had 1-2 LNM and 354 >2 LNMs. Patient’s age, larger size and lymphovascular invasion of the primary tumour, extracapsular extension of the LNMs, and morphology of the lymph nodes in US were the factors, which remained statistically significantly associated with >2 LNMs. These factors were included in the predictive model. Conclusions: The BLES procedure is an acceptable method for the management of small benign and high-risk breast lesions. Thus, a great amount of diagnostic surgical biopsies can be avoided. Oncoplastic BCS is as safe as conventional BCS, though it is used for larger, multifocal and more aggressive tumours. It enables BCS for patients who otherwise were candidates for mastectomy. Reoperation rates and LRFS were comparable for ROLL and RSL in patients with impalpable breast cancer treated with BCS. The 4th study provides a well performing patient-specific prediction model for evaluating the nodal tumour burden in clinically node-positive breast cancer patients. The prediction model could be helpful in the decision-making on the optimal axillary treatment in these patients.
  • Hakala, Sanja Maria (Helsingin yliopisto, 2020)
    There are intricate links between the evolution of sociality and the spatial population structures created by dispersal. In ants, the evolution of the most complex societies, supercolonies, is strongly connected to limited dispersal. The supercolonies consist of hundreds of interconnected nests where thousands of queens and their workers cooperate over large areas. Supercolonies arise from simpler family units when large proportions of daughter queens are philopatric and stay in their natal colony as additional reproducing queens instead of dispersing by wing. This allows the colonies to grow quickly and colonize large areas, but also increases social conflicts due to very low local relatedness in these societies. In this thesis I inspect the evolution and maintenance of ant supercolonies, by focusing on dispersal traits and the consequences of dispersal in socially polymorphic Formica ants. Formica have both simple family-based monodomous colonies and complex supercolonies, and some species have also intraspecific variation. To lay a sound theoretical background for my work, I begun by synthesizing current knowledge of dispersal evolution in ants. In my literature review I showed how eco-evolutionary feedbacks link the evolution of ant dispersal strategies and social organization, and pinpointed the most relevant future research directions. To be able to inspect some of the hypotheses formulated in the review, I clarified the species identification of one of my intended study species, Formica fennica with molecular methods, and concluded that the populations I study should be treated as conspecific to Formica exsecta. I analyzed the individual dispersal traits of six socially variable species of Formica ants to assess whether dispersal ability varies between monodomous and supercolonial societies in accordance to the observed behavioral difference. According to my results the dispersal behavior of these species is likely not restricted by their morphology or resources the individuals get from their natal colonies. Overall the traits of all species and both sexes indicate good flight ability, with overall male bias and large variation both among and within species. The increased philopatry in supercolonial species and populations is more a behavior change: the queens are philopatric even though the society provides them resources for dispersal. However, I observe a small decrease of male flight muscle ratio in supercolonial species, which indicates strong coevolution of the sexes. In order to better understand the outcomes of limited dispersal in supercolonial Formica, I analyzed the behavioral and genetic structure of a dense supercolonial population of Formica pressilabris. The population is genetically viscous at a small spatial scale, but still not genetically structured by location on a larger spatial scale. This indicates that although dispersal is limited within the population, a large enough proportion of individuals do disperse to keep the local populations connected. Interestingly, when analyzing worker behavior among the polydomous nests, the observed aggression pattern indicates that they are not a single cooperative unit – but also not clearly separate colonies. The sensitive behavioral assay developed for this study shows that workers allow a proportion of individuals from outside nests to enter their own nest material, but are slightly more aggressive towards individuals from further away. This indicates the population is only partially cooperative over the whole nest aggregation, and shows that the inner structures of Formica supercolonies should be analyzed in more detail. This thesis sets light on ants’ dispersal ability and behavior, and demonstrates the crucial role of dispersal in the evolution of their different social structures. My results also raise new questions about possible conflicts over dispersal in ant societies. 
  • Björklund, Mia (Helsingin yliopisto, 2020)
    The basic unit of all life forms is a cell, and all multicellular organisms are the result of programmed cell divisions of a single fertilised oocyte. This intricately controlled process, where a cell duplicates its DNA, grows and divides into two daughter cells, is called the cell cycle. Maintaining the appropriate control of the cycle is critical for the homeostasis of an organism. When the control fails, it may result in uncontrolled cell proliferation, one of the hallmarks of cancer. Cell cycle can be promoted or inhibited by signalling pathways induced by intra- or extracellular cues. Signals such as growth factors and hormones can bind cell surface or nuclear receptors causing signalling events and/or gene transcription resulting in positive or negative cell cycle regulation. External environment such as nutrient availability, or changes in energy metabolism can also signal to the cell cycle machinery, preventing cell division under high energy expenditure or external stress conditions. Central proteins in cell cycle regulation are the Cyclin-dependent-kinases, CDKs, and their cyclin partners. They phosphorylate other proteins causing changes in their activity or abundance, eventually leading to events required for cell duplication, such as DNA synthesis and chromosome segregation. CDK activity is in turn regulated by phosphorylation and cyclin abundance as well as the presence and binding of CDK-inhibitor proteins such as p27Kip1. P27Kip1 belongs to the Ink4-family of inhibitors, and can also function as an assembly factor for some CDK-cyclin complexes. We identified a form of p27Kip1, which was not bound to CDKs (p27NCDK) but was increased under growth restricting conditions such as TGF-β growth inhibition or serum starvation. On the other hand, inhibition of growth promoting pathways such as the PI3K-pathway was also found to increase the levels of p27NCDK. We also discovered that cellular stress induces the levels of p27NCDK, and appears to do so mainly via the AMP-activated protein kinase AMPK. AMPK is a kinase that is activated under energy stress conditions, like strenuous exercise. In this work we also investigated the crosstalk of these pathways and found points of convergence including p27NCDK and TGF-β pathway protein Ski. Ski negatively regulates TGF-β signalling pathway by binding the TGF-β signalling molecules. Ski is rapidly degraded upon TGF-β stimulation thereby allowing the signal to pass. We discovered that the PI3K-pathway intersects with TGF-β pathway as the PI3K-pathway kinase Akt phosphorylates Ski, thereby destabilising it. Destabilisation of Ski leads to an induction of a TGF-β target gene Smad7. Given that Smad7 is another negative regulator of TGF-β signalling, several genes such as the CDK-inhibitor p15 are downregulated. Concomitant activation of Akt and TGF-β therefore reduced induction of p15 and relaxed cell cycle controls. In addition the effects of external stress on cell cycle were investigated in a human prostate epithelial cells. Surprisingly, these cells did not undergo cell cycle arrest in response to ionising radiation. These cells were noted to have low or undetectable levels of Wee1 kinase, which normally exerts an inhibitory phosphorylation on CDK2 and CDK1 in response to external stress. Due to lack of inhibition, CDK2 activity remained high even after high doses of radiation. In this work we identified different points of cross talk between cell cycle promoting and inhibiting signalling pathways. These findings have significance in cancer and cancer treatment, which is often based on inhibiting the hyper activation of cell cycle promoting pathways by using hormones, radiation or small molecule compounds.
  • Huotari, Antti (Helsingin yliopisto, 2020)
    This dissertation focuses on stochastic and computational finance. It contains an introductory chapter and four essays. The first three of the essays are related to the optimal consumption and portfolio choice problem. The last essay deals with implied volatility modelling of swaptions. The first two essays are devoted to optimal portfolio and consumption when a consumer has habit preferences. The first essay focuses on finding an explicit solution when the underlying assets are allowed to follow non-Markovian dynamics and the preferences of the consumer are determined by the hyperbolic risk aversion utility function (HARA). The second essay presents a numerical method for solving the optimal portfolio in the habit case. By exploiting the Monte Carlo covariation method, it is possible to solve the optimal portfolio problem in the habit case. The approach is flexible in the sense that it is allows to make different kinds of assumptions about the behaviour of financial assets. The third essay considers the consumption-portfolio choice model when the stock prices follows a geometric Lévy process. Due to the lack of closed form solutions, numerical methods have been developed. In the case of the Lévy process, it is possible to form a so-called partial integro-differential equation (PIDE) and solve it by using a finite difference method. In the essay, an explicit-implicit option pricing method is utilized and a Markov chain approximation method is proposed for solving an optimal consumption and portfolio choice in the Lévy process case. The standard procedure for finding implied volatilities is based on Black's model which assumes a lognormal distribution of underlying prices and constant volatility. The last essay of this dissertation proposes pricing swaptions by assuming normally distributed swap rates with jumps rather than log-normally distributed rates. The pricing formula has been used to find implied volatility. The method is a combination of Bachelier's option pricing formula with normally distributed stock prices and a jump-diffusion formula for modelling variation which is based on swaption data. It is particularly useful in the case of a low interest rate and high volatility market.
  • Pham Duc, Dan (Helsingin yliopisto, 2020)
    Lipid disturbances reflect the dysregulation of molecular pathways associated with metabolic syndromes and neurological diseases like Alzheimer’s disease and Huntington’s disease. Several factors underlay the pathogenesis of lipid disorders, including accumulation of lipids, disturbed cell signaling, inflammation, mitochondria dysfunctions, ER stress and activation of cell death pathways. Here we have studied the roles of the neurotrophin, NGF and pro-NGF, and their receptor, p75NTR, a member of the tumor necrosis factor (TNF) superfamily, in lipid regulation. NGF and p75NTR have been previously studied in the nervous system but they are also expressed in non-neuronal cells, particularly after tissue injury and inflammation. In our study, we have used various cell and molecular biology methods, as well as protein methods, to elucidate the function of p75NTR in hepatocytes and neuronal cells. We have further employed p75NTR gene-deleted mice, and CRISPR/Cas9-mediated gene inactivation in human hepatocyte cells to elucidate the mechanisms of p75NTR in LDLR regulation. We have thus identified a molecular pathway by which NGF and pro-NGF influence SREBP activation leading to altered LDLR regulation and LDL uptake involving caspase-2/caspase-3 actions in Huh7 hepatocyte cells. Furthermore, we provide insight into the influence of LDL particles on neurite outgrowth in neuronal cells. RNA-sequencing analysis of wild-type and p75NTR-KO mice has demonstrated further that lipogenic genes are altered in the absence of p75NTR. There was also a down-regulation of serum cholesterol in p75NTR-KO mice in comparison with controls. Our findings showed further that NGF and pro-NGF are elevated, together with an increase in LDLRs in ob/ob and db/db mouse livers. This work will add to our understanding of p75NTR in health and disease, and may open up new possibilities to identify novel therapeutics to combat fatty liver and various metabolic disorders.
  • Saku, Sami (Helsingin yliopisto, 2020)
    Total joint arthroplasty (TJA) is the gold-standard treatment for severe hip and knee osteoarthritis. In recent decades, the hospital length of stay (LOS) has reduced substantially largely due to the widespread implementation of fast track protocols. Although the results are now better than ever and most patients have joint replacement without complications, some patients experience one or several deviations from the fast track protocol. In healthcare systems similar to those in Finland, knowledge on these deviations is sparse. This doctoral thesis sought to elucidate some of the deviations in TJA in a Finnish healthcare system. The study population consisted of TJA (i.e. total hip arthroplasty [THA] and total knee arthroplasty [TKA]) patients that underwent surgery at Helsinki University Hospital between 2014 and 2017. The study aimed to identify the reasons and risk factors for delayed discharge and 90-day readmissions after primary TKA. The study also aimed to assess early postoperative emergencies by evaluating the use of an Emergency Response Team (ERT) in the arthroplasty ward. Lastly, the study aimed to evaluate a novel phone consultation service for TJA patients and thereby elucidate common post-discharge concerns. The median LOS after TKA was 3 days. The main reasons for delayed discharge were related to functional recovery and pain. Risk factors for a discharge after the third postoperative day were older age, higher American Society of Anaesthesiologists (ASA) score, shorter preoperative walking distance, general anaesthesia, longer duration of surgery, longer time spent in Post-Anaesthesia Care Unit, and surgery later in the week. The 90-day readmission rate was 8.0% after primary TKA. The most common reasons for readmission were surgical site infection and knee pain. Independent predictors of readmission were psychiatric disease, asthma, a preoperative valgus malalignment, and a preoperative knee flexion deficit. The rate of ERT calls was approximately 7 per 1000 admissions. The most common criteria that triggered the ERT call were decreased level of consciousness, hypotension, and low oxygen saturation. Half of the patients could be treated at the ward after ERT intervention, and the other half was moved to the Intensive Care Unit. Common causes of the emergency included drug-related side effects, pneumonia, and pulmonary embolism. Concerns regarding prescribed medication, wound problems, and mobilization triggered most of the phone consultation service calls. The answering nurse alone resolved two thirds of all calls. Thirteen percent of the patients received instructions to visit the Emergency Department (ED) and half of them had a condition requiring treatment. Only two patients (0.7%) that should have been directed to the ED did not receive such instructions. This study identified several new risk factors for deviations in TJA. Due to the single-payer healthcare system, the possible confounding effect of insurance status did not confound the results. Despite differences in healthcare systems, both LOS and the readmission rate were similar to those previously reported. Considering the present study, a phone consultation service seems to reduce the amount of unnecessary ED visits. Employing an ERT service likely reduces the amount of ICU admissions after TJA surgery.
  • Tikker, Laura (Helsingin yliopisto, 2020)
    The anterior hindbrain segment rhombomere 1 (r1) generates in its ventral (basal) region GABAergic and serotonergic neurons that give rise to various nuclei in the adult brainstem that participate in the modulation of mood and motivation. This thesis focuses on the function of specific transcription factors (TFs) and their co-regulators that control the differentiation of r1derived neurons and their subtypes. First, we characterized early ventral r1 development to determine which neurons are generated in this area. In general, the developing neural tube can be divided dorso-ventrally into multiple progenitor domains that have distinct gene expression patterns and give rise to diverse cell types. We found that ventral r1 contains at least three different progenitor domains. Using genetic fate mapping in the mouse, we determined that the two most ventral progenitor domains (Nkx2-2+ rp3 and rpvMN) produce serotonergic neurons and oligodendrocytes, whereas the more dorsal progenitor domain (Nkx6-1+ rp2) generates GABAergic and glutamatergic neurons. By combining single-cell RNA sequencing (scRNAseq) and expression analyses of subtype-specific TFs, we show that embryonic ventral r1 contains molecularly distinct populations of post-mitotic GABAergic and glutamatergic precursors. We further report that GABAergic neurons from ventral r1 give rise to multiple GABAergic nuclei in the anterior brainstem, such as the posterior substantia nigra pars reticulata (pSNpr), rostromedial tegmental nucleus (RMTg) and ventral tegmental nucleus (VTg), whereas GABAergic neurons of the dorsal tegmental nucleus (DTg) originate from progenitors located in dorsal region of r1. Second, we analysed the functions of GATA TFs and their regulators in the development of r1derived GABAergic neurons by conditional mouse mutagenesis. We showed that GATA2 and GATA3, together with their co-factor TAL1, act as neuron-type selectors in early post-mitotic precursors to promote a GABAergic over glutamatergic neuron fate. Analysis of these mutants during later developmental stages showed that GABAergic neurons in the pSNpr, RMTg and VTg were absent, while the number of glutamatergic neurons was increased in other nuclei such as the interpeduncular nucleus (IPN) and the laterodorsal tegmental nucleus (LDTg). We found that ZFPM1 and ZFPM2, two GATA cofactors, are also expressed in GABAergic neuron precursors in r1. However, ZFPM2 does not function as a neuron-type selector in these cells, but rather is required for the proper development of pSNpr, RMTg and VTg GABAergic neurons. Finally, we studied the role of GATA2, GATA3 and ZFPM1 in the development of dorsal raphe (DR) serotonergic neurons in r1. Conducting overexpression experiments in chicken embryos, we demonstrated that GATA2 and GATA3 guide the differentiation of serotonergic neurons in the absence of their TAL1 partner, which is vital for GABAergic differentiation. We determined that GATA2 acts as a neuron-type selector and is important for all post-mitotic serotonergic neuron precursors to acquire serotonergic identity, whereas GATA3 is required for the differentiation of specific subtype of serotonergic neurons from r1. In addition, GATA2 and GATA3 are necessary for the development of non-serotonergic glutamatergic neurons in the DR. It was further shown that the GATA cofactor ZFPM1 is essential for the correct development of serotonergic neurons in DR subregions DRVL (ventrolateral part of dorsal raphe) and DRD (dorsal part of dorsal raphe). Loss of ZFPM1 function resulted in increased anxiety-like behaviour and elevated contextual fear memory, a phenotype that was alleviated by chronic treatment with fluoxetine, a selective serotonin reuptake inhibitor (SSRI). In conclusion, this work reveals neuronal subtypes present in and mechanisms involved with anterior brainstem development and that are important in the determination of behavioural phenotypes. Furthermore, it demonstrates that a complex gene regulatory system, where functions of GATA family selector TFs are modulated by their cofactors, is employed to achieve cell diversity in the central nervous system, mechanisms of which share marked similarities with cell fate determination programs in other developing tissues, such as the hematopoietic system.
  • Grönvall, Maiju (Helsingin yliopisto, 2020)
    Postpartum hemorrhage (PPH) complicates approximately 4% of all deliveries. In recent years, abnormally invasive placenta (AIP) has emerged as an increasing cause of PPH. Women with a history of cesarean section and presenting with placenta previa (PP) are at high risk for AIP. Antenatal detection of PP and AIP diminishes the risk of PPH and other complications. It is inconclusive whether PP type (major or minor) makes a significant difference in obstetric outcomes. Although there are several known risk factors, PPH still occurs often in primiparous women without any detectable risk factors. First-line treatment of PPH includes the use of uterotonics and tranexamic acid, laceration repair, and removal of placental tissue. If bleeding continues, the following treatment options have traditionally been surgical procedures: ligation of the uterine arteries, uterine compression sutures and hysterectomy. These procedures require advanced surgical skills. Avoiding hysterectomy, and thus infertility, is also one main goal, especially among primiparous women. Readily available, simple, fertility-sparing treatment modalities are needed. Over the last two decades, the Bakri balloon (Cook® Medical Incorporated, Bloomington, IN, USA) tamponade (BBT) and interventional radiology procedures (IRP) have been used increasingly in the treatment of PPH. The Bakri balloon is exclusively designed for obstetric use. It can be inserted into the uterus or the vagina depending on the bleeding site. IRPs include pelvic arterial embolization (PAE) and the use of prophylactic balloon occlusion in the pelvic arteries. IRPs can be used both in acute massive PPH and also prophylactically in women who are at high risk for PPH due to anticipated AIP. There were only a few publications on BBT before our study commenced (2012). In our hospital, PAE had been used for 10 years without evaluating the effectiveness and safety of our own process. The psychological and physical outcomes of complicated deliveries and IRPs were also controversial and unclear. Our treatment protocol arranged follow-up only for women with major PP. The aims of the studies were to determine the effectiveness and safety of BBT and PAE. The long-term psychological and physical sequelae of IRPs were also explored. The accuracy of our screening and treatment protocol for PP was evaluated, and obstetric outcomes between major and minor PP were compared. The study data were collected retrospectively from Helsinki University Hospital registers (years 2001 ¬̶ 2014). A structured questionnaire concerning long-term psychological and physical outcomes was sent to women who underwent IRPs. The success rate for BBT was 86% and for PAE 89%. None of the complications was related to BBT. Only one major PAE-related complication occurred (rupture of the iliac artery). The results of the inquiry showed a high incidence of adverse psychological outcomes. Many women consider counseling to be inadequate after a stressful delivery. Due to our mid-pregnancy screening protocol, almost one-fifth of the women with major or minor PP at term had no follow-up after mid-pregnancy. The first bleeding episode occurred at 37 gestational weeks or later in 21.9% of these women and massive PPH (>2500 ml) in 15.6% of these women. Two women had undiagnosed AIP leading to hysterectomy. These complications could possibly have been avoided if the diagnosis had been established earlier. It was also remarkable that the incidence of AIP was equal in women with major and minor PP. Additionally two out of seven women with BBT failure and three out of five with PAE failure had AIP as a cause of PPH. In conclusion, BBT and PAE are safe and effective treatment modalities. The procedures had a significant role in the PPH treatment protocol. The availability of these procedures is mandatory due to the unpredictable nature of PPH and the increasing incidence of AIP. Our screening and follow-up protocols for PP are revised based on our results. A systematic counseling protocol for women who had PPH and a complicated delivery should be implemented in every delivery unit.

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