Browsing by Subject "medicine"

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  • Metso, Tiina (Helsingin yliopisto, 2013)
    Cervicocerebral artery dissection (CeAD) is one of the leading causes of ischemic stroke in the young and middle-aged adults. The pathophysiology of CeAD is poorly understood. CeAD patients probably have a constitutional, partly genetic weakness of the vessel wall, which predisposes to tears in the connective tissue within the vascular wall in occurrence of environmental triggers of the disease, such as acute infection, migraine, or minor trauma. For this thesis project, we collected a register of all consecutive CeAD patients treated at the Helsinki University Central Hospital, Finland, between 1994 and 2008. In the first part of the thesis, we studied 103 patients with intracranial artery dissections (IAD). IADs could be divided into 2 distinct groups: i) non-aneurysmatic IADs presenting without subarachnoid hemorrhage that are associated with favorable outcomes and safe anticoagulant therapy, and ii) aneurysmatic IADs, characterized by subarachnoid hemorrhage and poorer prognosis. Secondly, we evaluated characteristics, prognostic factors and vascular risk factors in 301 CeAD patients. We found association of CeAD with male sex, and possible association with smoking and migraine, especially migraine with aura. Stroke severity and recent infection were associated with poorer outcome. The three other publications for the thesis were part of the CADISP project (Cervical Artery Dissection and Ischemic Stroke Patients), an international consortium focusing on research on CeAD. For the clinical part of CADISP, 983 patients with CeAD, 658 patients with ischemic stroke due to causes other than dissection, and 1170 healthy control subjects were included in 8 countries and 18 centers. In the CADISP cohort, vascular risk factors were less frequent in CeAD patients compared with young patients with a non-CeAD ischemic stroke. In comparison with healthy controls, hypercholesterolemia, obesity, and overweight were less frequent in CeAD patients, whereas CeAD patients had more hypertension. This suggests that hypertension may be a risk factor for CeAD. Finally, migraine was more common in CeAD patients with stroke than in patients with ischemic stroke due to a cause other than CeAD. We detected no excess of ischemic strokes, specific arterial distribution or other clinical or prognostic features characteristic to migraineous CeAD patients compared to those without migraine.
  • Ho Huu, Tho (Helsingin yliopisto, 2015)
    The aim of this study was to utilize molecular biology knowledge to develop novel amplification-based technologies, which enable enrichment of challenging nucleic acid targets to a level sufficient for detection, including those with extremely long, GC-rich and/or repetitive sequences and low-abundance single nucleotide RNA variants in the excess of alternative variants. We have introduced multiple heat pulses in the extension step of a PCR cycling protocol to generate a novel amplification technology (HPE-PCR), which temporarily destabilize secondary structures, in order to enhance DNA polymerase extension over GC-rich sequences. Different GC rich target sequences in the human genome, extremely long Fragile X GGC repeats and Myotonic Dystrophy type 1 CTG repeats have been used as models to develop and validate this novel technology. In order to detect a low-abundance RNA variant, we devised a novel technology using a competitive Extendable Blocking Probe (ExBP) in the reverse transcription reaction for allele-specific priming with superior selectivity. In ExBP-reverse transcription, the mismatch priming site on the alternative variant is blocked by a perfectly matched ExBP. This initiates formation of a stable cDNA-RNA hybrid that completely blocks false cross-priming by the target specific primer. In experimental models, the ExBP-based reverse transcription assay allowed for detection of multiple mutation types on different genes in at least 1000-fold excess of wildtype RNA and detection was linear over a 4 log dynamic range. This technique not only reveals the presence or absence of rare mutations with an exceptionally high selectivity, but also provides a convenient tool for accurate determination of RNA variants in different settings, such as quantification of allele-specific expression. In conclusion, we have established HPE-PCR and ExBP-RT techniques to enable enrichment of different nucleic acid templates that are currently challenging to detect by PCR, such as long, GC rich and/or repetitive sequences as well as low-abundance point mutations in a vast excess of wildtype alleles. These techniques expand the capacities of current PCR technology; provide versatile and convenient research tools and open many new possibilities for its applications in molecular diagnostics.
  • 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.
  • Lähteenmäki-Uutela, Anu; Rahikainen, Moona; Camarena-Gómez, María Teresa; Piiparinen, Jonna; Spilling, Kristian; Yang, Baoru (Springer Nature, 2021)
    Aquaculture International 29 (2021), 487–509
    Macroalgae-based products are increasing in demand also in Europe. In the European Union, each category of macroalgae-based products is regulated separately. We discuss EU legislation, including the law on medicinal products, foods including food supplements and food additives, feed and feed additives, cosmetics, packaging materials, fertilizers and biostimulants, as well as biofuels. Product safety and consumer protection are the priorities with any new products. Macroalgae products can be sold as traditional herbal medicines. The novel food regulation applies to macroalgae foods that have not previously been used as food, and organic macroalgae are a specific regulatory category. The maximum levels of heavy metals may be a barrier for macroalgae foods, feeds, and fertilizers. Getting health claims approved for foods based on macroalgae is demanding. In addition to the rules on products, the macroalgae business is strongly impacted by the elements of the general regulatory environment such as agricultural/aquacultural subsidies, maritime spatial planning and aquaculture licensing, public procurement criteria, tax schemes, and trade agreements.
  • Dudek, Mateusz (Helsingin yliopisto, 2016)
    Alcohol addiction is one of the most prevalent brain disorders in the world. A major hurdle for reducing alcohol-related harms and developing effective treatments is the poor understanding of neural processes responsible for the development of dependence and addiction. Alcohol has been shown to affect various neurotransmitter systems; however, the mesolimbic dopamine (DA) system, which projects from the ventral tegmental area (VTA) to the nucleus accumbens (NAc), has been thought to play a key role in producing the reinforcing effects of alcohol. The VTA region has also been suggested to be the anatomical site for the interaction of the dopaminergic system with the opioidergic and γ-aminobutyric acid (GABA) systems. Here, manganese-enhanced magnetic resonance imaging (MEMRI) and behavioral tests were used to study drug-induced alterations in brain activity of the alcohol-preferring AA (Alko Alcohol) and heterogeneous Wistar rats. MEMRI is based on the ability of paramagnetic Mn2+ ions to accumulate in excitable neurons, thus enhancing the T1-weighted signal in activated brain regions. Mn2+ ions can also be transported anterogradely and retrogradely in neurons, released to the synaptic cleft, and taken up by other neurons. These properties allow MEMRI to measure long-term changes in brain activity, as well as map neural pathways involved in acute and long-term drug actions, including drug reward and toxicity. The AA rats exposed to alcohol compared to water controls displayed a widespread and persistent activation in brain regions that have been previously linked with alcohol reinforcement. Similarly, activity in neural pathways originating in the NAc and projecting caudally to the midbrain was enhanced in alcohol drinking rats. Moreover, this alcohol-induced activation was blocked by systemic naltrexone (NLX) administration. Comparison of naïve AA and Wistar rats revealed a lowered basal activity in the caudal linear nucleus (CLi) of AA rats, which was restored by voluntary alcohol drinking. The intra-CLi γ-aminobutyric acid type A receptor (GABAA) agonist muscimol produced a dose-dependent increase in alcohol drinking, blocked by co-administration of the GABAA antagonist bicuculline, suggesting that the CLi GABAergic system is involved in the regulation of alcohol reward. MEMRI was also employed for assessing stimulant-induced toxicity. Methamphetamine and mephedron displayed disparate effects on brain activity, as methamphetamine produced widespread decreases in activity, whereas mephedron increased activity in limited brain areas. Taken together, the use of MEMRI for mapping alcohol- and stimulant-induced alterations in functional brain activity revealed networks and specific pathways that have potential for guiding further translational efforts to develop medications for drug abuse disorders, as well as for evaluating drug-induced toxicity.
  • Akmal, Jan Sher; Salmi, Mika; Mäkitie, Antti; Björkstrand, Roy; Partanen, Jouni (2018)
    The purpose of this study is to demonstrate the ability of additive manufacturing, also known as 3D printing, to produce effective drug delivery devices and implants that are both identifiable, as well as traceable. Drug delivery devices can potentially be used for drug release in the direct vicinity of target tissues or the selected medication route in a patient-specific manner as required. The identification and traceability of additively manufactured implants can be administered through radiofrequency identification systems. The focus of this study is to explore how embedded medication and sensors can be added in different additive manufacturing processes. The concept is extended to biomaterials with the help of the literature. As a result of this study, a patient-specific drug delivery device can be custom-designed and additively manufactured in the form of an implant that can identify, trace, and dispense a drug to the vicinity of a selected target tissue as a patient-specific function of time for bodily treatment and restoration.
  • Awad, Shady (Helsingin yliopisto, 2021)
    Chronic myeloid leukemia (CML) is an adulthood leukemia that accounts for 15% of all leukemia patients. The hallmark of the disease is the BCR-ABL1 fusion gene. The development of Tyrosine kinase inhibitors targeted therapy has led to dramatic improvement in CML management with the life expectancy of CML patients approaching normal rates. Nevertheless, certain challenges in CML management remain unmet. CML progression from the chronic phase (CP) to the blast phase (BP) occurs in 5% of CML patients and is associated with dismal survival. Additionally, a minority of CML patients express p190-BCR-ABL1 isoform, which is associated with inferior treatment responses. Characterization of the mechanisms underlying the pathogenesis of high-risk CML is warranted to enable optimization of the therapeutic approaches for these patients. We aimed to investigate the role of mutations at different phases of CML, and to identify genetic biomarkers that allow better risk assessment and optimization of CML management. Furthermore, we integrated genetic and drug sensitivity profiling to identify effective drugs in a personalized medicine approach. In study I, we applied comprehensive sequencing techniques to a cohort of 59 CML patients, including 19 BP and 40 CP patients. In comparison to CP, BP patients demonstrated higher mutational load and were associated with recurrent mutations involving ABL1, ASXL1, and RUNX1 genes. Fusion genes were also identified as recurrent genetic abnormalities in BP patients. Cancer-associated gene mutations correlated with inferior treatment outcomes in CP patients. Finally, we presented two BP patients who were managed using a personalized approach and achieved good responses, highlighting the potential power of this strategy in BP management. In study II, RUNX1 was selected as an example driver mutation in CML progression. RUNX1 mutations were identified in 35% of patients. We also identified mutagenic AID/RAG axis activity which was specific to RUNX1-mutated patients. RUNX1-mutated BP patients demonstrated the overexpression of lymphoid transcription factors as well as aberrant expression of lymphoid antigens (CD19/CD7). We identified targeted therapies with enhanced sensitivities in RUNX1-mutated blasts. We further used CRISPR/Cas9 gene editing to model RUNX1 mutations in cell lines. Finally, we demonstrated the efficiency of CD19 CAR T-cell immunotherapy in targeting RUNX1-mutated blasts. In study III, we performed genomic and phosphorylation profiling for four p190-CML patients and validated findings in two progenitor cell lines (Ba/f3 and HPC-LSK). We demonstrated novel evidence for the p190-specific activation of IFN/JAK1/STAT1 pathway in CML. Other important signaling pathways included Src and PAK1 signaling. We also identified novel p190-specific drug vulnerabilities. Finally, we validated these findings in a cohort of Ph+ ALL patients. In conclusion, our study provides novel insights into the molecular pathogenesis of high-risk CML patients, including BP-CML and p190-CML patients. We identified potential biomarkers, which can be involved in the risk-assessment of CML. Integration of genetic and drug screening data enabled the identification of promising drug candidates. Taken together, we highlighted the potential value of the personalized medicine approach for optimizing the management of high-risk CML patients.
  • Ovaskainen, Harri; Airaksinen, Marja; Närhi, Ulla (Suomen farmasialiitto, 2004)
    This article provides an overview of the role of medicines in Finnish health care, and the structure of pharmaceutical services. The major public health concerns will be briefly presented to give a gramework for understanding national drug consumption patterns. In this connection, the main principles of the public social insurance system covering the whole population and most of the prescription medications for chronic diseases will be discussed. The different actors in the drug distribution chain are also introduced, including community pharmacies. At the end of the article, there will be a short overview on the Finnish pharmaceutical education system that is based on two academic degreesÖ Bachelor and Master of Science in Pharmacy, both of whick have their own professional roles in health care. At the end, a short review presents the goals of drug policy by 2010, set by the ministry of Social Affairs and Health in September 2003.
  • Mosakhani, Neda (Helsingin yliopisto, 2013)
    Recently, discovery of microRNA has provided new insights into cancer research, revealing the role of miRNAs in various biological processes, and evidence shows that their deregulation in many cancers has prognostic and predictive significance. Although specific miRNAs have been discovered in the malignancies studied in this thesis: colorectal cancer (CRC), giant cell tumor of bone (GCTB), acute lymphoblastic leukemia (ALL), and acute myeloid leukemia (AML), very little still is known about the association of miRNAs with progression and their response to treatment. By applying novel microarray techniques, we profiled miRNA expression in CRC, GCTB, ALL and, AML. In the study focusing on primary tumors of 60 metastatic CRC (mCRC) patients, we detected BRAF mutations in 5 and KRAS mutations in 15 cases. In addition to 46 altered miRNAs in mCRC patients with and without KRAS mutation vs. normal colon tissue, we observed an miRNA signature associated with KRAS status when we compared 15 patients with mutant KRAS with 40 patients without this mutation. Four differentially expressed miRNAs, over-expressed miR-92a, miR-127-3p, miR-486-5p, and under-expressed miR-378, were evident in the mutated KRAS group vs. wild-type KRAS group. In another study on CRC, miRNA profiling in primary tumors of 33 mCRC patients with wild-type BRAF and KRAS allowed identification of miRNAs related to their response to anti-EGFR monoclonal antibody treatment. We found up-regulated miR-31* and down-regulated miR-592 in progressive disease (PD) compared to that in disease control (DC). Evaluation of mRNA levels of SLC26A3 and ATN1, drug-related genes and of miR-31* target genes showed their lower level of expression in PD vs. DC. Moreover, correlation between overall survival and miRNA expression assessed by two approaches, cluster analysis and the Cox proportional hazard regression model, revealed two common miRNAs, miR-140-3p and miR-1224-5p, to be related to survival in both analyses. As for the study of the metastatic and non-metastatic GCTBs, we found 12 miRNAs as being differentially expressed (miR-136, miR-513a-5p, miR-494, miR-224, miR-542-5p). Expression levels of eight genes such as NFIB, TNC, and FLRT2 correlated inversely with miRNA results. The expression levels of miR-136 and its target gene, NFIB, were verified by use of qRT-PCR. The level of NFIB protein also was higher in metastatic than in non-metastatic GCTBs. Further, we tested the protein expression level of NFIB in an independent validation cohort of 74 primary archival GCTB specimens to assess the power of NFIB as a prognostic marker. Immunodetection showed a higher frequency of NFIB over-expression in primary tumors that developed metastases than in the disease-free group. Moreover, we studied the miRNA expression profiles of primary tumors of 90 bone marrow core biopsies of ALL patients, including 11 patients with paired samples at diagnosis and at relapse. We found a set of miRNAs (miR-1281, miR-1225-3p, miR-877*, miR-423-5p, miR-29c) significantly related to survival (q less than 0.05). Further validation of miR-423-5p expression by qRT-PCR confirmed microarray analysis results and showed a direct correlation with survival. In comparisons between the diagnosis-relapse pairs, expression of miR-654-5p and miR-431 between the two groups significantly differed, and these miRNAs were down-regulated in relapse samples. Comparison of miRNA profiling of 15 chemorefractory and 18 chemosensitive AML patients showed that the differentially expressed miRNAs were miR-363, miR-532-5p, and 342-3p, all of which were over-expressed in chemorefractory vs. chemosensitive patients. Verification by use of qRT-PCR of both miR-363 and miR-532-5p revealed similar results as with microarray. The miR-363 target genes RGS17 and HIPK3 both have been associated with drug response. These studies provide new information about genomic changes involved in progression and resistance to treatment in various types of cancer, and also highlight the power of applying genomic-wide array screening techniques in malignancies. The novel findings in these studies may serve as a useful resource for future studies and aid in development of novel therapeutic targets to increase the survival rates of cancer patients.
  • den Hollander, Bjørnar (Helsingin yliopisto, 2015)
    In recent years there has been a large increase in the use of a new kind of amphetamine- type stimulants known as substituted cathinones. These compounds have a short history of human use, and little is known about their potential neurotoxicity. Two of the most popular substituted cathinones, 4-methylmethcathinone (4-MMC, mephedrone) and 3,4- methylenedioxymethcathinone (MDMC, methylone} are, aside from their β-ketone group, close structural analogues of potentially neurotoxic amphetamines such as methamphetamine (METH) and 3,4-methylenedioxymethamphetamine (MDMA, ecstasy). This has led to concern about the potential neurotoxicity of these novel compounds, and warrants a closer investigation into their possible long-term neurotoxic effects. METHODS The long-term effects of METH and MDMA as well as 4-MMC and MDMC were assessed using a range of biochemical assays, including assessment of monoamine levels and their transporters. The effects on brain activity were investigated using manganese-enhanced magnetic resonance imaging. Furthermore, behavioral experiments assessing cognition and neuropsychiatric function were performed. Finally, in vitro experiments in a neuroblastoma cell line were performed to identify mechanisms responsible for the observed differences in toxicity between the amphetamines and cathinones. RESULTS Unlike METH and MDMA, which produced strong reductions in dopamine and serotonin levels or brain activation, 4-MMC produced few notable effects on monoamine levels and had only minor effects on brain activation, although MDMC produced a reduction in 5-HT levels similar to MDMA. No clear effects on behavioral tests of memory function were observed as both increases and decreases in test performance were seen following 4- MMC and MDMC. In vitro experiments revealed that cathinones differ from amphetamines in their redox properties, and 4-MMC produced different effects than METH on the mitochondrial electron transport chain. CONCLUSIONS The substituted cathinones 4-MMC and MDMC do not appear to be more neurotoxic than METH and MDMA. If anything, they show a more favorable safety profile. Therefore, these substances do not appear to present an imminent and severe threat to public health. From a harm reduction perspective, these compounds may be good alternatives toMETH and MDMA. However, future work is needed to assess with certainty the long- term effects of amphetamine-type stimulants in humans.
  • Mustelin, Linda (Helsingin yliopisto, 2012)
    Background: Obesity is one of the leading causes of ill-health in the Western world, and physical inactivity is a known risk factor for obesity. Obesity as well as physical activity and cardiorespiratory fitness are influenced by both genetic and environmental factors. However, whether they share the same genetic vs. environmental etiology has rarely been studied. Aims: To explore the relative contributions of genetic and environmental factors on body mass index (BMI), waist circumference, physical activity and cardiorespiratory fitness, to explore whether physical activity modifies the relative contribution of genetic factors on BMI and waist circumference and to assess the effects of obesity on cardiorespiratory fitness and expression of genes of mitochondrial oxidative phosphorylation in young adult twins. Subjects: 4,798 twins born in 1975 - 1979 (FinnTwin16 cohort) and followed up from the ages of 16 to 23 - 27 years; two subsamples of the FinnTwin16 cohort: one consisting of 24 monozygotic (MZ) pairs concordant and discordant for obesity and the other consisting of 152 MZ and DZ (dizygotic) twin pairs selected to represent a wide range of intra-pair differences in BMI; 1,294 twins born in 1983 - 1987 and followed up from the ages of 11 - 12 to 20 - 25 years (FinnTwin12 cohort). Measures: Cohorts: Self-reported height, weight and waist circumference, a physical activity index calculated from the product of self-reported physical activity intensity, duration and frequency, the Baecke physical activity questionnaire. Subsamples: Measured height, weight and waist circumference, measured body composition and insulin sensitivity, cardiorespiratory fitness, gene expression in adipose tissue. Results: Physical activity decreased the influence of genetic factors on BMI and waist circumference. The association between sports activity and obesity and of that between sports activity and cardiorespiratory fitness was largely due to genetic factors influencing both traits. Genetic factors contributed significantly to individual differences in physical activity, with genetic factors explaining between 41% and 64% of the variance in four physical activity indexes. Acquired obesity was associated with poor cardiorespiratory fitness and lowered transcript levels of genes involved in mitochondrial function in adipose tissue. Conclusions: The influence of genetic factors on obesity measures was smaller in physically active subjects as compared to inactive subjects indicating a geneenvironment association between physical activity and genes predisposing to obesity. This suggests that the individuals at greatest genetic risk for obesity would benefit most from physical activity. Genetic factors influence both would benefit most from physical activity. Genetic factors influence both physical activity and obesity traits and explain a major part of their relationships. Acquired obesity causes poor cardiorespiratory fitness, insulin resistance and downregulation of genes involved in mitochondrial function.
  • Bramante, Simona (Helsingin yliopisto, 2015)
    Despite the numerous advances in cancer therapy over the past 50 years, cancer still remains the major cause of mortality worldwide, and thus new and more efficient treatments are needed. Oncolytic viruses have shown promising results in preclinical and clinical studies for the treatment of solid tumors, but their efficacy often remains low. A multitude of viral strains, such as adenovirus, have been engineered to become tumor-selective and to stimulate the immune system against the tumors. One example of oncolytic virus is Ad5/3-D24-GMCSF, a tumor-selective 5/3 chimeric oncolytic adenovirus armed with the immunostimulatory granulocyte-macrophage colony-stimulating factor (GM-CSF). In this thesis, we studied the utility of Ad5/3-D24-GMCSF in the treatment of sarcoma, melanoma and breast cancer. The virus showed strong oncolytic potential in vitro and antitumor efficacy in immunodeficient animal models. Furthermore, replication-linked GM-CSF production stimulated the differentiation of human monocytes into macrophages, important for induction of antitumor immune responses. In immunocompetent Syrian hamsters with soft-tissue sarcoma (STS) tumors, Ad5/3-D24-GMCSF reached non-injected tumors through vascular circulation, suggesting its utility for the treatment of metastatic disease. We showed that combining Ad5/3-D24-GMCSF with chemotherapeutics that possess immunogenic properties (doxorubicin and ifosfamide) and that selectively reduce circulating regulatory T-cells (cyclophosphamide), enhanced adenoviral replication and induced immunogenic cell death, setting the stage for clinical testing of combination regimens. Finally we reported safety and possible signs of efficacy in 40 patients with advanced sarcoma, melanoma and breast cancer, who were treated in the context of an Advanced Therapy Access Program (ATAP). Treatments were overall well-tolerated, and objective signs of treatment benefits were also observed. Therefore, our results confirm previous good data regarding Ad5/3-D24-GMCSF as a promising agent for treatment of cancer. Furthermore, our data may prove useful for clinical development of oncolytic adenoviruses combined with low-dose chemotherapy for the treatment of advanced sarcoma, melanoma and breast cancer, and may help to design optimal clinical trials.
  • Santos, João Manuel (Helsingin yliopisto, 2020)
    The onset of cancer progression is largely mediated by a dysfunctional adaptive immune system which fails to actively eradicate tumor cells. Adding to the demand for viable long-term curative options for advanced or metastatic cancers, immunotherapeutic strategies have been developed with the intent of efficiently restoring antitumor immunity. An approach to achieve the latter consists in the generation and expansion of tumor-specific T-cells for adoptive infusion in cancer patients, in a process defined as adoptive T-cell therapy (ACT). Clinical application of ACT has provided effective and durable antitumor responses in some advanced or metastatic cancers, however employment of toxic pre- and postconditioning in ACT treatment regimens does not render this therapeutic modality accessible to all cancer patients. The applicability of ACT is further narrowed considering that its efficacy is tightly linked to a niche of tumor types which feature high immunogenicity and low immunosuppressive capabilities. Given the safety and immunological effects of oncolytic adenovirus therapy, we hypothesized that oncolytic adenoviruses coding for tumor necrosis factor alpha (TNFα) and interleukin-2 (IL-2) (Ad5/3-E2F-D24-TNFα-IRES-IL2) could supply, additional proinflammatory stimulus for improved safety and, efficacy of ACT in immunosuppressive tumors. For in vivo validation of this concept, Syrian hamsters were used, considering that human adenovirus replication is possible, human TNFα and IL-2 are bioactive and, tumor-infiltrating lymphocyte (TIL) therapy can be performed. Studies in mice with cytokine-coding replication-incompetent adenoviruses allowed, detailed immunological characterization after virus therapy and the use of T-cell receptor (TCR)-engineered ACT. Ex vivo studies in ovarian cancer clinical samples allowed the study of Ad5/3-E2F-D24-hTNFα-IRES-hIL2 in an immunosuppressive microenvironment in the context of TIL therapy. Local therapy with Ad5/3-E2F-D24-hTNFα-IRES-hIL2 induced systemic virus spread, increased TIL trafficking and NK cells and, decreased M2 macrophages in local and distant tumors. Cytokine-coding adenovirus treatment negatively impacted tumor growth with the increased expression levels of chemokines and other immunologically important genes. Replacement of a lymphodepleting regimen with TNFα and IL-2 coding adenoviruses allowed comparable antitumor efficacy and survival of animals receiving ACT. Adenovirus therapy and lymphodepleting preconditioning promoted similar CD8+ T cell infiltration and dendritic cell maturation profiles, but with the adenovirus promoting higher proinflammatory status. The use of IL-2-coding adenovirus therapy instead of high-dose IL-2 postconditioning allowed the best tumor growth control in animals receiving ACT. Such results, were accompanied by the intratumoral accumulation of CD8+ T-cells, M1-like macrophages and decreased levels Tregs, a phenomenon not seen in control groups or animals receiving high-dose IL-2 postconditioning. Importantly, the confinement of adenovirus-derived cytokine production to the tumor site enables negligible systemic toxicity as opposed to the toxicity caused in vital organs and blood from animals receiving pre and post-conditioning regimens. Furthermore, Ad5/3-E2F-D24-hTNFα-IRES-hIL2 therapy caused significant changes in the immunosuppressive ovarian tumor microenvironment, including CD8+ and CD4+ activation and increased shedding of IL-2, TNFα, IFN-γ and CXCL10. Such favorable effects reflected on the increased IFN-γ tumor-reactivity of autologous TILs transferred into virus-infected ex vivo tumor cultures, a phenomenon not associated with PD-L1 expression. In conclusion, TNFα and IL-2 coding oncolytic adenoviruses appear to be a potent immunotherapeutic which can amplify the local and systemic effects of ACT in immunosuppressive tumors while lowering the toxicity of ACT.
  • Oulasvirta, Jelena (Helsingin yliopisto, 2021)
    Children form a small proportion of all emergency medical services (EMS) contacts. A Finnish study by Harve et al. (2016) discovered that young children aged one or less were overrepresented in children's contacts with EMS. Further, falls, respiratory problems, seizures, and poisonings accounted for half of all of their emergencies. Finally, an unexpected number of children were assessed by paramedics, but not transported to the hospital. Rooted in the Harve group findings, this study explored EMS contacts with children focusing on pediatric subpopulations such as children who had had seizures, infants, and children who after evaluation by EMS personnel were not transported to any health care facility. In addition, the study investigated whether and how the COVID-19 pandemic and restrictions intended to curb the pandemic impacted out-of-hospital (OOH) emergencies in children during the first wave. The thesis consists of four register-based retrospective cohort studies conducted in the Helsinki University Hospital area. Children under 16 years old formed the study population overall, except in the one study where the study population comprised 0- to 11-month-old infants. The data on EMS contacts were gathered from both OOH and in-hospital electronic patient record systems. The study periods lasted from three months to five years. EMS contacts with children comprised from 3.9% to 4.8% of all contacts. Infants constituted about 0.4% of all EMS contacts. EMS contacts with children who suffered seizures occurred in the 13% of pediatric missions. The non-transportation rate was high and ranged from 26.7% in pediatric seizure patients to 60.1% in infants. Hospitalization or pediatric intensive care unit (PICU) admissions were seldom necessary. On-scene mortality was low. Only a few patients died during follow-up periods, and none of these deaths were traceable to EMS contact. The study recognized several risk factors for secondary outcomes after EMS contact with children. Dispatch codes "dyspnea", "vomiting /diarrhea" and "mental illness" were associated with unintended visit after non-transportation. In infants, dispatch codes "dyspnea" and "urgent dispatch before symptom-specific code known", as well as problems in the neonatal period were associated with hospitalization and PICU admissions. In contrast, dispatch code "low-energy fall" was less associated with unintended visits after non-transportation, and hospitalizations and PICU admissions in infants. Fewer EMS contacts with children occurred during the first wave of the COVID-19 pandemic. However, the proportion of children in the most urgently dispatched and transported priority category A rose significantly. In addition, EMS personnel requested additional help more frequently to the scene. Thus, children appeared to be acutely more ill during the restriction period. COVID-19 infection among children with EMS contact was infrequent. In conclusion, EMS encounters with children were uncommon and around half of the children were not transported after evaluation by EMS personnel. The current practice appeared to be safe. The high non-transportation rate may reflect the changing role of EMS and possible non-medical needs of families with children. Taking into account the risk factors that were identified in this study could further improve patient safety among EMS contacts with children. Consideration that restrictions during the pandemic may have unexpected side effects on children's health may help to guide and direct curbing measures during future sudden pathogen outbreaks.
  • Hautala, Johanna (Helsingin yliopisto, 2021)
    A congenital heart defect (CHD) is the most common congenital structural anomaly, and it is observed in 1% of live births. In Finland, approximately 550 children per year are born with a CHD. The defect is critical in 10%, requiring immediate care soon after birth. Due to developed care, most CHD patients survive adulthood, but a critical CHD is still one of the most important reasons for perinatal mortality. Information on CHD risk factors is still scarce. By uniting data from quality, nationwide registers, this study assessed the total and live birth prevalence of the selected CHDs and the effect of the implementation of national fetal anomaly screening on prenatal detection rates nationally and regionally in an 11-year cohort. In addition, the monthly variation of these CHDs was analyzed, and possible analogous variations n in viral or bacterial infections were evaluated. Prenatal anomaly and chromosomal screenings have become a pivotal part of health care. In Finland, voluntary, nationwide, free-of-charge ultrasound screenings have been provided by the municipalities for every pregnant woman since January 2010. Fetal heart screening is based on a four-chamber view and outflow tract views. This study selected the univentricular heart (UVH, in which one ventricle is taking care of circulation) as an index anomaly for the four-chamber view and transposition of the great arteries (a TGA, in which the aorta arises from the right ventricle and the pulmonary trunk from the left ventricle) for the outflow tract views. The data of all live births, stillbirths and terminated pregnancies, and maternal characteristics were gathered with ICD codes in 2004–2014. The cases with a congenital diaphragmatic hernia and a CHD in 2002–2011 were collected for Study III. The population-based cohort included data from the National Institute for Health and Welfare’s; Finnish Register of Congenital Malformations, Medical Birth Register, The Register of Induced Abortions, Hospital Discharge Register, National Infectious Diseases Register, causes of death from Statistics Finland, and the National Register of Pediatric Cardiac Surgery maintained by Children’s Hospital at Helsinki University Hospital. Nationwide prenatal detection rates increased after implementing a systematic screening program: in UVH from 50% to 83% and in TGA from 12% to 41%. However, significant regional differences were found; especially in TGA, detection rates varied between 13% and 65% and remained still non-optimal. Significant monthly variation in early pregnancy was observed in a UVH and a TGA, but no analogous variation with studied bacterial and viral infections was found. Multiple pregnancies, obesity, and pregestational diabetes were more common among the CHD population than all parturients. None of the studied risk factors affected prenatal detection. Some extra-cardiac malformations, such as a congenital diaphragmatic hernia, were associated with the development of hypoplastic left heart syndrome (HLHS), warranting the close follow-up of heart development in fetuses with a diaphragmatic hernia. Neither the screening program nor the prenatal diagnosis affected simple TGA mortality. None of the prenatally diagnosed TGA infants died, and total mortality was 9%. Most of the deceased died in maternity hospitals without a prenatal diagnosis, and postoperative mortality was only 1%. Older maternal age and lower gestational age at birth were associated with higher mortality. Maternal prepregnancy obesity and perioperative risk factors were associated with a higher need for health care resources during the first year of life. In conclusion, the implementation of a systematic fetal screening program increased prenatal detection rates of UVH and TGA. However, for a TGA, there were significant regional differences, and the prenatal detection rates of TGA were still not optimal. These results suggest establishing the previously recommended prospective fetal screening register to assure equal, adequate, and quality screening nationwide.
  • 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.
  • Wang, Wei (Helsingin yliopisto, 2013)
    Cholesterol is an essential structural component of mammalian cells. It is taken up by cells from low density lipoproteins (LDL) where it is stored as cholesteryl esters. Cholesterol can also be synthesized by cells from precursor sterols, such as desmosterol. In cells, cholesterol can be further metabolized to other bioactive molecules, including steroid hormones. In this thesis, we explored selected aspects in the regulation of steroid metabolism. The three studies included in the thesis focused on lysosomal acid lipase (LAL), 24-dehydrocholesterol reductase (DHCR24), and amyloid precursor protein (APP). LAL hydrolyzes cholesteryl esters and generates free cholesterol, while DHCR24 converts desmosterol to cholesterol. APP is the precursor of the pathogenic Aβ peptide in Alzheimer s disease. The physiological function of APP is not known but it has recently been implicated in the regulation of cholesterol metabolism. We characterized the uptake and LAL-mediated degradation of LDL-derived steroid esters in mammalian cells. Although the cellular breakdown of LDL-carried cholesteryl esters is well characterized, the pathway for LDL-derived steroid hormone esters is less well understood. Our results showed that dehydroepiandrosterone-fatty acyl esters (DHEA-FAE) in LDL particles could be taken up by LDL receptors, after which DHEA-FAE was hydrolyzed partially by LAL and converted into two major metabolites, 5α-androstanedione and androstenedione. We also addressed the potential functions of desmosterol, an intermediate precursor of cholesterol, during brain development. Desmosterol transiently accumulates in the developing brain of mammalian species; however, it is not known how this happens, nor what the desmosterol accumulation might serve for. We provided evidence that the DHCR24 enzyme is repressed by progesterone, and that desmosterol accumulation parallels gestational progesterone accumulation. Furthermore, we proposed desmosterol promotes sterol secretion from glial cells and maintains an ample supply of active sterols in the developing brain. Finally, we investigated how APP regulates cholesterol metabolism in mammalian cells. APP has mostly been studied in neurons but the protein is ubiquitously expressed. In this study, we found that APP and its proteolytic fragments regulate cholesterol biosynthesis and LDL-uptake via the transcription factor SREBP2. We also showed that in glial cells two APP ectodomains, APPsα and APPsβ, acted opposingly in cholesterol synthesis regulation, depending on the APP α- vs. β-cleavage.
  • Tuomisto, Karolina (Helsingin yliopisto, 2021)
    Obesity, type 2 diabetes and cardiovascular disease are major causes of morbidity and mortality in the world. They are known to be linked by an unhealthy diet and low levels of physical activity. Furthermore, obesity is a risk factor for type 2 diabetes, and both increase a person’s cardiovascular risk. Subclinical inflammation has been associated with each of the conditions, but there have been limited attempts to establish whether it is another major link between them. To test our hypothesis subclinical inflammation being an important biological link between the obesity-type 2 diabetes-cardiovascular disease trifecta, we analysed whether subclinical inflammation precedes and predicts, obesity, type 2 diabetes, cardiovascular disease and all-cause death. Three large, population-based prospective Finnish cohorts and one North American cohort were used for the analyses of the present study, namely FINRISK 1992, FINRISK 2002, DILGOM 2007 and the FHS Offspring Study. The Finnish cohorts were further linked to nation-wide registers, providing information on deaths, disease diagnoses and drug purchases. We explored links of subclinical inflammation with obesity in both cross-sectional and longitudinal settings using the DILGOM 2007 cohort. Inflammation markers were associated with obesity measures at baseline, as well as with weight gain, increasing waist circumference, increasing body fat percentage, or increasing body-mass index (BMI) during a 7-year follow-up. However, after adjusting for baseline BMI, longitudinal associations were no longer significant for any of the outcomes. This suggests that subclinical inflammation does not precede obesity, and may be its consequence rather than the cause. With the help of advanced metabolomics, we identified 545 eicosanoids and related oxylipins in the FINRISK 2002, DILGOM 2007 and FHS Offspring Study cohorts. Using stepwise Cox regression analysis, we determined that a three-eicosanoid risk score was associated with incident type 2 diabetes in three independent cohorts. Our findings imply that lipid-derived mediators of inflammation may play a role in the prediction of incident type 2 diabetes. Using a case-cohort design based on the follow-up of the FINRISK 1992 cohort, we found inflammation markers to be independent predictors of cardiovascular disease and all-cause death, especially in men. IgG class antibodies to periodontal pathogens as well as endotoxin were also associated with incident cardiovascular events, although endotoxin’s association was not independent of cholesterol levels. Further epidemiological studies and randomised clinical trials exploring links between inflammation markers and cardiovascular disease have confirmed the role of subclinical inflammation in the development of atherosclerosis. The findings of this thesis suggest that subclinical inflammation is associated with both metabolic and atherothrombotic aspects of common public health problems. It seems to be at least one of the links between obesity, type 2 diabetes, cardiovascular disease and death. The findings, together with current literature, suggest opportunities for early detection, estimation of disease risk and prevention as well as therapeutic targeting of subclinical inflammation to reduce the risk of cardiovascular disease. Once we understand better the biological processes underlying subclinical inflammation and the obesity-type 2 diabetes-cardiovascular disease trifecta, we may be able to develop safe and cost-effective therapies addressing metabolic and atherothrombotic characteristics of each of these diseases.
  • Niilekselä, Pia (Helsingin yliopisto, 2017)
    Entrance to academic studies does not automatically lead to commitment in one's studies. There may be differences in student commitment across different learning environments. In the present study, combinations of problems in studying medical students experience were investigated in a lecture-based learning environment (n = 246) and in a problem-based learning environment (n = 231). Also differences between the combinations in task avoidance and differences between the combinations in academic achievement were investigated in each learning environment. Medical students were classified in different learning environments by K-means cluster analysis by cases into groups based on the following variables: exhaustion, lack of self-regulation, lack of interest and distress. Three groups of commitment among medical students were identified in the lecture-based learning environment: committed, carefree and dysfunctional students. The profiles were related to task avoidance but not to study success. The committed students expressed less task avoidance than the carefree students and the dysfunctional students. The latter two groups of medical students did not differ from each other in this case. Also three groups of commitment among medical students were identified in the problem-based learning environment: committed, committed carefree and dysfunctional students. The profiles were related to task avoidance and study success. The dysfunctional students expressed more task avoidance than the committed carefree students and the committed students. The latter two groups of medical students did not differ from each other in this case. The committed students and the committed carefree students gained better grades than the dysfunctional students. However, the former two groups of medical students did not differ from each other in this case. The implications of the study for research are discussed.
  • Schreier, Nadja K. (Helsingin yliopisto, 2014)
    Background. The environment has a major impact on human beings. Extreme environmental conditions such as hot temperatures can have huge health impacts, as shown during the heat wave in Europe that occurred during the summer 2003. The main causes of death were non-communicable diseases (NCDs) such as respiratory and cardiovascular diseases. Natural and man-made disasters can cause the collapse of health infrastructure through a combination of marked increase in demand due to injuries, diseases and increased stress levels and the physical disruption/destruction of hospital buildings, roads and transport that follows such disasters. Extreme weather events and disasters are predicted to increase in the course of the ongoing climate change. Therefore, impacts on NCDs are very likely to increase, which raises the importance of the hitherto paucity of knowledge about this research area. Aims. This study investigates the associations of weather conditions, temporal variations, in addition to the impact of a disaster, namely the bombings of Helsinki during the Second World War (WWII) on NCDs, specifically for coronary heart disease (CHD), cerebrovascular disease, type 1 diabetes mellitus (T1DM), hypertension, and obesity. Materials. Three main data sets were used for this study: 1) All fatal and non-fatal coronary events in seven cities in Finland recorded in the years 1983, 1988, and 1993 (n=9243), 2) Data that originate from the Helsinki Birth Cohort Study (HBCS) include information about birth characteristics and about life-long disease outcomes in addition to deaths of subjects born in Helsinki between 1934-1944 (n=13 039), 3) Data that originate from the DiaMond project including standardized data from 112 centers in 56 countries of all children aged between 0-14 years with diagnosis of T1DM during 1990-1999 (n=31 091) Methods. The following methods were used to achieve the specific aims: 1) Comparison of regression models with weather and temporal variation variables for the prediction of coronary events was implemented for the assessment of the influence on the case-fatality of the events, 2) Log-linear regression with Fourier terms were used to assess seasonal patterns for the incidence of childhood T1DM in different geographical locations, 3) Survival analysis and regression models were used to assess life-long health outcome due to exposure to bombings in utero, and to outdoor ambient temperature at the time of conception. Results. Influences of temperature at the time of conception for hypertension and obesity were observed. Women who were conceived during the months with the warmest mean temperatures of the time-series were found to have a significantly higher probability of developing hypertension in adult life. Furthermore, women conceived during those months with very low mean temperatures had lower BMI, lower risk of obesity and also lower fat percentage in adult life. The seasonality of the incidence of the T1DM in children was demonstrated to be a global phenomenon. In addition it was shown that the further from the equator a location is in terms of latitude the higher is the probability of that location to exhibit a seasonality pattern for T1DM. A slight positive influence for the life-long development of CHD and cerebrovascular disease was found for women who were in utero during the bombings of Helsinki in WWII. Furthermore, the case fatality of coronary events during the 1983-1993 period turned out to be negatively influenced by temporal variation. Case-fatality of CHD was higher in the December holidays and on Sundays. An attempt to predict coronary events on the basis of the weather forecast for the same study period appeared not to have any useful value. Conclusions. This study contributes to the research of the fundamentals about the influence of weather, temporal variation, and disasters on NCDs. The results showed that hypertension, obesity, T1DM, CHD, and cerebrovascular disease were particularly affected by those factors. The ongoing climate change will potentially increase the impacts on NCDs. Preparedness for these increases - including the prevention of disease and the prevention of the further exacerbation of a disease – is an important task for the near future. Further, the collection of data in developing countries where data are sparse needs close collaboration between interdisciplinary scientific teams in order to address the complexity of this type of research and to contribute to the preparedness of health authorities in such challenging regions.