Faculty of Medicine

 

Recent Submissions

  • Pohjola, Anni (Helsingin yliopisto, 2021)
    Brain arteriovenous malformations (AVM) are rare vascular anomalies in which the cerebral arteries and veins are connected without the normal intervening capillary bed. Most often, in roughly half of the cases, the event leading to diagnosis is intracranial hemorrhage. The second most common symptom is a focal epileptic seizure, leading to diagnosis in one-third of the cases. AVM incidence in the general population is approximately 1/100,000 person-years. The average age for AVM diagnosis is slightly over 30 years, meaning that the disease often affects working-age people. It is also a significant cause of intracranial hemorrhage in children and young adults. The AVM hemorrhage is lethal in, on average, 5–25% of patients. In this thesis we have studied patients in the Helsinki AVM database using the 15D health-related quality of life (HRQoL) instrument and questionnaire data about lifestyle. Our database consists of 805 AVM patients treated in the Helsinki University Hospital Department of Neurosurgery between 1942 and 2014. Of them, 325 patients answered the mailed questionnaire sent in 2016 and comprise the study cohort of this thesis. Our research revealed that after a mean 17.6 years (SD ±12.0 yr) of follow-up the HRQoL of treated AVM patients in general was, when considering the difficulty of the disease, only modestly decreased. Also, most of the patients had been able to return to work. In the multivariate model, the decreased HRQoL of AVM patients was explained by older age, sex (being female), difficult refractory epilepsy, difficult location or structure of the AVM, and more than one hemorrhagic episode. Our results support active AVM treatment in those cases which the procedure can be done safely and the treatment-related risks do not exceed the estimated cumulative rupture risk. Another novel finding from our study cohort was that the prevalence of smokers was significantly higher in AVM patients when compared to a matched general population. The high prevalence, especially during the diagnosis, inspires more vigorous investigation of the role of cigarette smoking in the currently unknown etiology of AVMs. With our final article, we participated in the on-going discussion in the scientific community about the statistical handling of the commonly used functional outcome instrument, the modified Rankin Scale. We showed, using our AVM patient cohort, that the popular dichotomous approach in outcome assessment could significantly bias research results.
  • Masalin, Senja (Helsingin yliopisto, 2021)
    Gestational diabetes mellitus (GDM) is a common metabolic pregnancy disorder, affecting 1 in 7 pregnancies on a global level. In Finland, the prevalence of GDM has increased rapidly in the recent decades and was 21% in 2018. GDM is a major public health concern, with adverse short- and long-term health implications for the woman and her offspring. Traditional risk factors for GDM include advanced maternal age, overweight and obesity, a family history of diabetes and an ethnicity with a high prevalence of diabetes. There are, however, other risk factors, referred to as non-traditional, that have been shown to increase the risk for type 2 diabetes but have been studied less or with conflicting results with regard to GDM. The aim of this thesis was to evaluate the impact of several non-traditional maternal risk factors (height, body size at birth, smoking status and socioeconomic status) on the risk for GDM. The thesis is part of the register-based follow-up Vantaa Birth Cohort study 2009–2015. Data has been collected from the Finnish Medical Birth Register, the Finnish Social Insurance Institution, the Finnish Tax Administration, and Statistics Finland. In Study I, encompassing 4,111 Finnish primiparous women and their singleton offspring, maternal height was inversely associated with the development of GDM, after adjustments for age and educational attainment (p = 0.018 for linearity). Independently, both maternal height and GDM were positively associated with the birthweight of the offspring (calculated as Z-score according to sex and gestational age; p < 0.001 for both). However, the interaction between maternal height and GDM was significant and an increase in birthweight was noted only in women within extreme height categories, group I ≤ 158 cm (p = 0.011), group IV 168–172 cm (p = 0.010) and group V ≥ 173 cm (p < 0.001). In Study II, encompassing 1,548 Finnish primiparous women, there was a positive correlation between maternal body size at birth (assessed as body surface area [BSA]) and adult anthropometry. The association between maternal BSA at birth and GDM was inverse (p = 0.015 for linearity), after adjustments for age, educational attainment, pre-pregnancy body mass index (BMI) and smoking. In Study III, encompassing 4,111 Finnish primiparous women and their singleton offspring, a positive relationship between smoking during pregnancy and GDM was observed. The prevalence of GDM was highest in the group of smokers who continued smoking after the first trimester, compared with those who quit, and non-smokers (p = 0.004 for differences between groups). In women without GDM, birthweight was lowest in newborns of smokers who continued smoking after the first trimester (p = 0.004 for differences between groups, adjusted for age and pre-pregnancy BMI). In women with GDM, offspring birthweight was not related to maternal smoking. In Study IV, encompassing 5,962 Finnish primiparous women, there was an inverse association between increasing maternal income level and the development of GDM, after adjustments for age, cohabiting status, pre-pregnancy BMI and smoking (p < 0.001 for linearity). Educational attainment also showed an inverse relationship with the development of GDM. In conclusion, maternal current height, BSA at birth, and socioecomonic status (assessed as both income and educational attainment) were all inversely associated with the risk for development of GDM. Further, maternal smoking during pregnancy increased the risk for GDM. Birthweight was lowest in newborns of women without GDM who continued smoking after the first trimester. However, among newborns of women with GDM, birthweight was not related to maternal smoking. Recognizing specific maternal risk factors is important in lifestyle conseling and targeted prevention of GDM. Hence, findings on the non-traditional risk factors evaluated in this thesis indicate they are of importance both from a clinical and public health perspective. However, future studies are needed to confirm the associations, taking possible additional confounding factors into account, as well as to verify the mechanisms behind these associations.
  • Karjalainen, Piia (Helsingin yliopisto, 2021)
    This thesis uses a randomized controlled trial (RCT) study setting to investigate the effectiveness of a parenting intervention (the Incredible Years®, IY) in modifying children’s behaviour problems, parenting practices and parents’ psychological well-being among families in child protection and other special support services. The study also explored parent’s perceptions of the program. A systematic review of the literature confirmed that there is solid research evidence on the effectiveness of parenting programs on child behaviour and parenting practices. However, the review also revealed a lack of evidence of the effectiveness of these programs with families in touch with child protection services (CPS). The study examined the effects of the intervention on child problem behaviour, parenting practices and parent’s well-being. Participants in the study were 3–7-year-old children with behaviour problems (N = 102, intervention group N = 50, control group N = 52) and their parents (N = 122). Parents in the intervention group received 19 sessions of the long IY Preschool Basic parenting program and the controls received treatment as usual (TAU), while on the waiting list (WL) for the next available parent group organized after the study. Results of the study show that child problem behaviour decreased more in the intervention group in comparison to control group before and after the intervention, when measured by using scale scores of ECBI Problem and cut-offs for clinically relevant cases (ECBI Problem and CBCL External). The intervention also increased positive parenting practices, although changes in parental stress or parents’ psychological well-being in the intervention group did not differ from parents in the control group. Child behaviour problems decreased at one year follow-up in both the intervention (N = 44) and the control groups (N = 45), although no differences between the groups were evident at the follow-up. The positive changes in child behaviour at home were not evident at day care or school at baseline, post-intervention or one-year follow-up, and there were no significant differences between the groups. The study also compared parents with (N = 43) and without (N = 19) CPS contact in terms of their satisfaction with the IY® Parenting Program. Satisfaction scores ranged between 5.8 and 6.2 (max 7) for all studied intervention domains. Mean attendance rate in the group sessions was 11.5 (SD 5.9), and 74% of participants attended at least nine out of 19 sessions. No group differences were found in satisfaction or attendance between CPS and non-CPS parents. Parents in CPS committed well to the program and found it as useful as parents without CPS contact. The results of the present study indicate promising evidence that parenting interventions such as the IY® parenting program may be effective in terms of child conduct problems in the short term in families within the CPS context. Sustaining the positive effects and generalizing them to day care and school contexts remains challenging in the context of child protection and other family support services in real-life conditions. IY® parenting program appears to be acceptable to parents involved in CPS, and their engagement to the program can be considered as reasonably good. Key words: child behaviour problems, parenting, parenting program, intervention, evidence-based, child protection services
  • Lahtinen, Alexandra (Helsingin yliopisto, 2021)
    Chronic insufficient sleep affects basic physiological processes and increases risk for various mental and somatic disorders. Despite the growing number of omics-studies, sleep laboratory studies conducted in human samples, as well as various experiments in animals, the biological mechanisms underlying the health consequences of curtailed sleep are not fully understood. This thesis was inspired by the hypothesis that the consequences of sleep loss may be reflected as changes in the epigenetic processes, with DNA methylation (DNAm) selected as the most feasible to study. The aim of this thesis was to elucidate biological pathways associated with chronic insufficient sleep, as well as to explore how transient and reversible DNAm changes triggered by sleep loss are. In the first study, a cross sectional genome-wide DNAm analysis (Epigenome-wide Association Analysis, EWAS) was performed in relation to self-reported insufficient sleep in individuals from a population-based sample and in relation to insufficient sleep (shift work disorder) among shift-workers from an occupational cohort. No genome-wide significant differences in DNAm were observed in cases versus controls. The study revealed that insufficient sleep was accompanied by the loss of methylation and DNAm alterations in genes enriched in nervous system development pathway. The karyoplot evidenced for several clusters of CpGs on various chromosomes, including a cluster of 12 CpGs on chromosome 17. The genes corresponding to these CpGs were previously associated with a rare genetic condition accompanied by disturbed sleep and inverted circadian rhythm. The second study examined dynamic DNAm changes in relation to recovery from a shift work disorder in the occupational cohort of shift workers across the genome. The results indicated that recovery during vacation leads to the restoration of DNAm and specifically affects genes involved in the activity of N-methyl-d-aspartate (NMDA) glutamate receptors. These findings provide evidence for the dynamic nature of human methylome and suggest CpG sites in genes Glutamate Ionotropic Receptor NMDA Type Subunit 2C (GRIN2C), cAMP Responsive Element Binding Protein 1 (CREB1), and Calcium/calmodulin Dependent Protein Kinase II Beta (CAMK2B) as putative indicators of recovery in a shift worker with shift work disorder. In the third study, we studied the effect of depressed sleep on DNAm in a sample of adolescents with comorbid depression and insomnia as compared to healthy controls. No genome-wide significant differences in DNAm appeared in cases versus controls. However, the top findings of DNAm analyses were enriched in the synaptic long-term depression (LTD) pathway, emphasizing the role of sleep in synaptic plasticity and the widespread physiological consequences of disturbed sleep. Based on these findings, it can be concluded that chronic insufficient sleep is associated with a specific DNAm pattern in blood leukocytes, evidencing for the systemic physiological wide-spread consequences of curtailed sleep. Some of these specific DNAm alterations appeared to be reversible, once individuals restored sleep during two weeks of vacation. Altogether, this thesis contributes to an understanding of the changes triggered by sleep loss in a highly complex and dynamic regulatory mechanism, human DNA methylome.
  • Zhou, Kecheng (Helsingin yliopisto, 2021)
    Sphingolipids, a major component of the plasma membrane, regulate various cellular activities and display essential physiological functions. The cellular processes that control sphingolipid homeostasis are complex and incompletely understood. The lysosomes are responsible for digesting intracellular and extracellular materials, including sphingolipids, and these organelles play a role as a hub in metabolic signaling, coordinating cellular anabolism and catabolism. Lysosome-associated protein transmembrane 4 B (LAPTM4B) is highly expressed in many types of cancers and associates with poor prognosis. On the cellular level, LAPTM4B affects cellular processes including nutrient sensing, autophagy, proliferation, cell migration, drug resistance, and sphingolipid homeostasis. Less is known regarding the function of LAPTM4B at the molecular level, because studies have been hampered by a lack of molecular tools and of specific LAPTM4B antibodies. In this thesis, we sought to elucidate the lipid and protein environment of LAPTM4B, and how these are coordinated to regulate downstream signaling events. In our first study, we combined approaches from biochemistry, computer simulations, and lipid biology to show that the third transmembrane domain of LAPTM4B contains a ceramide-regulated element consisting of a sphingolipid interaction motif and an adjacent aspartic acid residue (D202). This feature is essential for regulating the interaction between LAPTM4B and 4F2hc, a subunit of the amino acid transporter CD98. The ceramide induced an interaction between LAPTM4B and 4F2hc, and this interaction promotes downstream mTORC1 signaling. In our second study, we characterized a novel monoclonal antibody, which we used to visualize the subcellular distribution of endogenous LAPTM4B for the first time. By site-directed mutagenesis of putative start codons, we identified LAPTM4B-24 as the major expressed and physiologically important isoform in a majority of human cells and tissues. We further showed that endogenous LAPTM4B has a fast turnover, and is regulated by nutrient availability and ceramide, pointing to a role at the crossing-point of sphingolipid metabolism and nutrient signaling. In our third study, we investigated the role of LAPTM4B in regulating the lipidomes of cells and the secreted extracellular vesicles. We found LAPTM4B to be sorted into intraluminal vesicles of multivesicular bodies and subsequently to be released from cells in small extracellular vesicles (sEVs). The secretion dynamics of LAPTM4B was dependent on the ceramide-regulated motif. Shotgun lipidomics revealed that LAPTM4B regulates the sphingolipid- and ether lipid content in cells and in sEVs. This thesis provides evidence that LAPTM4B is a dynamically regulated protein that functions at the intersection of sphingolipid metabolism and nutrient signaling. Crosstalk between LAPTM4B and ceramide facilitates nutrient signaling, and these processes may in part underlie the association observed between LAPTM4B and cancer progression. Future work is warranted to elucidate the molecular function of LAPTM4B in the endosomal-lysosomal system, and to elucidate the LAPTM4B isoform-specific functions in different organs and diseases, as well as to solve the three-dimensional structure of LAPTM4B. Such knowledge will deepen our understanding of LAPTM4B- and ceramide-related pathophysiology in cancers and in sphingolipid-metabolism disorders.
  • Pant, Shishir Mani (Helsingin yliopisto, 2021)
    Loss of epithelial integrity is a common phenomenon in all advanced solid tumors and this cellular event importantly facilitates tumor cell proliferation, invasion, and metastasis. In breast cancer, for example, cancer cells have to overcome cell-cell and cell-matrix junction-enforced epithelial barriers to progress from ductal carcinoma in situ, to invasive ductal carcinoma, and to ultimately form metastasis. Oncogene-driven deregulation of pericellular proteolysis along with growth factor-mediated transcriptional switch to epithelial-to-mesenchymal gene expression assist cancer cells to overcome epithelial integrity-mediated tumor suppression. Historically, overactive matrix metalloproteinases have been considered as the main protease mediators of epithelial integrity loss. However, recent evidence also suggests the involvement of serine proteases in this process. The aim of this Ph.D. thesis was to determine the role of the serine protease hepsin in breast cancer progression. Hepsin is a type II transmembrane serine protease upregulated in 90% of prostate cancer and frequently overexpressed in breast, cervical, ovarian, gastric, endometrial, and renal cell carcinomas. Despite several studies reporting hepsin upregulation in breast cancer, its role in breast tumorigenesis has been largely unknown. We found hepsin protein levels upregulated in all main subtypes of breast cancer, with the highest overexpression (60%) in triple-negative breast cancer. When combined with Myc oncogene, hepsin overexpression promoted tumor growth and reduced survival in the breast cancer mouse model. Mechanistically, hepsin overexpression activated the HGF-mediated MET pathway and induced loss of cell-cell and cell-matrix cohesion. We also found that the Ras-Raf-MEK pathway upregulates and activates heat shock factor 1 (HSF1) to stabilize hepsin protein. Furthermore, we found that hepsin is involved in deregulating epithelial integrity downstream of Ras, which can be blocked by inhibiting hepsin protease activity. Finally, we developed a small molecule inhibitor as a chemical probe to study hepsin biology. Using an integrated design, synthesis, and screening platform we managed to improve the potency of our initial hit towards hepsin from 1 μM to 22 nM and specificity over uPA from 30-fold to >600 fold. To summarize, the studies compiled in this dissertation validated hepsin upregulation in breast cancer, demonstrated that hepsin overexpression promotes mammary tumorigenesis, identified loss of epithelial integrity and HGF/MET pathway activation as potential oncogenic alterations associated with hepsin overexpression, identified a role for Ras-Raf-MEK-HSF1 pathway in hepsin upregulation, and developed hepsin specific small molecule inhibitor as a molecular tool to study hepsin biology.
  • Malani, Disha (Helsingin yliopisto, 2021)
    Acute myeloid leukemia (AML) is an aggressive and heterogeneous malignancy of the hematopoietic system. This thesis explores functional precision medicine approaches to target subsets of AML, in vitro, ex vivo and in the clinic. The experimental strategies focused on high-throughput drug sensitivity and resistance testing (DSRT), exome and RNA-sequencing. The real-time implementation of molecular and functional data for relapsed and refractory patients highlighted the opportunities of future individually tailored therapies in AML. We investigated the functional and molecular basis of cytarabine resistance to identify the molecular mechanisms of resistance and drugs that overcome the resistance. Cytarabine resistant AML cell lines MOLM-13 and SHI-1 variants were generated by long-term culturing. The cells were subjected to genomic sequencing, gene expression profiling and DSRT along with AML patient samples. We found a marked increase in glucocorticoid sensitivity in SHI-1 cytarabine resistant variants and in two AML patients treated with cytarabine-based regimens. Analysis of a larger set of relapsed or refractory AML patient samples revealed wild type FLT3 was significantly associated with sensitivity to glucocorticoids. The finding suggests glucocorticoids could be an effective class of drugs for a subset of cytarabine resistant AML patients with wild type FLT3 gene. We sought to identify drugs showing the discrepancy in responses between cell lines and patient samples, and potential drug sensitivity biomarkers. The drug responses, exome and RNA sequencing data were analyzed from 45 AML patient samples and 28 AML cell lines. Dasatinib, a multi tyrosine kinase inhibitor, was observed as one of the drugs with remarkably high sensitivity in the patient samples compared to the established cell lines. The upregulation of the KIT pathway was significantly associated with ex vivo dasatinib efficacy. The KIT pathway upregulation and ex vivo dasatinib sensitivity were found to be correlated with clinical response to dasatinib in three AML patients. Our results warrant testing dasatinib in a clinical trial for the AML patients with ex vivo dasatinib sensitivity and gene expression-based KIT pathway upregulation. A real-time precision systems medicine strategy was applied to identify targeted therapeutic options and biomarker associations in 252 samples from 186 AML patients. The integration of molecular profiling and DSRT data revealed ex vivo drug efficacies and underlying mutations and gene expression biomarkers for the subsets of AML patient samples. We developed a multidisciplinary functional precision medicine tumor board (FPMTB) to guide clinical therapy decisions for chemorefractory and recurrent (R/R) AML patients in a prospective real-time non-randomized clinical study. Our data suggest that functional precision medicine could have clinical utility, although it needs supportive evidence from formal prospective clinical trials. This thesis highlights novel avenues to define therapeutic opportunities for specific molecular subgroups of adult AML. The strategies described here could be useful for prioritizing drug development, identifying molecular subsets and drug response biomarkers, defining ideas for clinical trials, as well as the direct implementation of the therapies in individual AML patients in the FPMTB system.
  • Holm, Matilda (Helsingin yliopisto, 2021)
    Colorectal cancer (CRC) is the third most common cancer worldwide, accounting for around 10% of the global cancer burden, and is second only to lung cancer in terms of cancer death. For patients with CRC, the overall 5-year survival rate is around 65%, although it is highly dependent on stage at diagnosis. Biomarkers are molecules that can be used for the detection of a disease, follow-up after radical surgery, monitoring of progression, detecting or assessing the risk of recurrence, and predicting prognosis. Glycans are carbohydrates that play important physiological roles in processes such as cell signaling, growth, and motility. Changes in glycans are seen during cancer and glycans are directly involved in different aspects of cancer such as proliferation, invasion, and metastasis. The proteome, which consists of all the proteins expressed in a cell, tissue, or organism, is dynamic due to factors such as posttranslational modifications, regulation of gene expression, and differential splicing of mRNAs. Changes in the proteome are also seen during cancer. The plasma proteome is a good candidate for studies due to the multitude of proteins it contains, the ease of obtaining samples, and the way it reflects the condition of the host. Mass spectrometry is often used to study the glycome and proteome in order to discover candidates for new biomarkers and to obtain new knowledge of how the levels of glycans and proteins change during cancer. The aim of this study was the glycomic and proteomic profiling of CRC with a focus on studying differences in glycan and protein levels depending on factors such as tumor location, stage, and patient outcome. Glycans were isolated from CRC tissue samples and healthy colonic tissue and analyzed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Separately, preoperative plasma samples were processed and analyzed using Ultra Performance Liquid Chromatography-Ultra Definition Mass Spectrometry. All samples were obtained from patients who underwent surgery at Helsinki University Hospital. The results were analyzed using methods including principal component analysis, Mann-Whitney U and ANOVA tests, hierarchical clustering, pathway analysis, the Kaplan-Meier method, log-rank tests, and Cox proportional hazards regression analysis. The main differences in glycan levels seen were between acidic glycans, several of which had significantly different levels between stage II and III CRC. Surprisingly, the only significant differences in glycan levels between samples from patients with cancer in the right and left colon were seen when samples were divided according to both tumor location and stage. Many significant differences were seen in the levels of glycans when compared between healthy colon and tumor tissue samples. Multiple plasma proteins were identified whose levels differed significantly between stage II and III CRC. The levels of 13 proteins were found to differ between stage II and III CRC regardless of primary tumor location. Significant differences in plasma protein levels were also observed depending on primary tumor location. Samples from patients with rectal cancer separated from samples from patients with colon cancer solely on the basis of plasma protein expression when analyzed using principal component analysis and hierarchical clustering. Several plasma proteins were identified of which altered levels were independently linked to significant differences in long-term outcome. Higher plasma levels of proteins such as ceruloplasmin and fetuin-B were linked to significantly improved long-term survival rates for stage II CRC patients, while higher plasma levels of signal-induced proliferation-associated 1-like protein 1 and the CNK3/IPCEF1 fusion protein were linked to significantly poorer long-term survival rates for stage III CRC patients. In conclusion, these glycomic and proteomic studies provide new knowledge of CRC at the molecular level and show that significant differences can be seen in the levels of specific glycans and plasma proteins depending on factors such as tumor stage, location, and patient outcome. These results lend further support to the notion that it may be important to consider colon and rectal cancer as separate entities. While multiple plasma proteins that could be of value for predicting cancer progression and, separately, patient outcome were identified, validation of their clinical utility is still needed. Further studies to investigate why the levels of certain glycans and plasma proteins differ depending on CRC stage, tumor location, or patient outcome are also warranted.
  • Toppinen, Mari (Helsingin yliopisto, 2021)
    Some viruses can establish life-long persistence in their hosts after primary infection. The main aims of this thesis were to investigate the persistence, molecular epidemiology, and evolution of human parvovirus B19 (B19V). B19V is a small single-stranded DNA virus that has been shown to persist in various human soft tissues. The disease associations or mechanisms of this persistence, both at the cellular and molecular level, have remained unknown. At the beginning of this thesis work, we developed a quantitative PCR (qPCR) method for the detection, quantification, and differentiation of all three B19V genotypes. The method was shown to be suitable for B19V diagnosis and research both in human body fluids and solid tissue samples. Measurement of the B19V load is essential in i) timing of the primary infection, ii) investigation of the persistence mechanisms, and iii) plasma pool screening in blood product manufacturing. Next, we performed in-depth studies on the B19V persistence in tonsil, bone marrow, and bone. B19V-DNA tissue prevalences were high (35-74 %). Our results were in line with previous publications (tonsils), showed a higher prevalence than earlier detected (bone marrow), and described an entirely new tissue harboring B19V DNA (bone). We described, for the first time, the cell type accounting for the lifelong B19V-DNA tissue persistence in tonsils. Our results showed that B19V persists preferentially in B cells and that the entry mechanism into these cells is antibody-mediated. Antibody-dependent enhancement (ADE) may account for the B19V symptoms during primary infection or play a role in the establishment of persistence. In B cells of four individuals over 45 years, we detected a B19V genotype 2 that had disappeared from circulation before the 1970s. As B19V does not evolve or reactivate within human tissues, these individuals must have carried the genotype 2 virus in their B cells for over 40 years, suggesting a survival time of several decades for these B cells. Indeed, immunological memory may be, in addition to antigen re-exposure, due to a decades-long survival of the original B cell clones. In addition to persistence, we investigated in this thesis B19V molecular epidemiology and evolution. We constructed several full-length genomic sequences of B19V genotypes 1 and 2. By combining our bone marrow and bone data, we observed that within an individual, a single B19V genotype is present. We found that the inverted terminal repeat (ITR) sequences, crucial for B19V replication, are similar in both genotypes, and thus, do not explain the disappearance of genotype 2. We searched B19V DNA from long bones of World War II (WWII) casualties and found an astonishingly high prevalence (45 %). This work, for the first time, shed light on the epidemiological occurrence of B19V in Northern Europe between ~1923 and 1944 and laid the foundation for a new research approach: archeovirology, i.e., the study of virus occurrence and evolution via ancient relics. Indeed, we describe in this thesis – first in the world – persistent viral genomes in human bone. In addition to B19V, we investigated the prevalences of altogether 37 human DNA viruses in contemporary femoral bones via qPCR and next-generation sequencing (NGS). We discovered several members of the parvo-, herpes-, papilloma- and polyomavirus families, as well as hepatitis B virus and torque teno virus. Thus, our findings revealed bone to be a much richer source of persistent DNA viruses than ever perceived. Our results show that human skeletal remains – both contemporary and ancient – are suitable material for the investigation of epidemiologies and evolutionary histories of DNA viruses. After our work on WWII bones, archeovirology has expanded: other groups have described B19V, hepatitis B virus, and variola virus sequences in thousands of years old dental and skeletal human remains. Ancient specimens will provide an unforeseen historical perspective on viruses and infectious diseases.
  • Cervera-Carrascón, Víctor (Helsingin yliopisto, 2021)
    Over the last ten years, the use of immunotherapeutic treatments for cancer has exponentially increased due to the promising responses across different tumour types. One of the particularities of the approach is that patients can develop long lasting curative responses. Unfortunately, those encouraging complete responses happen only in a minority of patients (< 10%). Immune checkpoint inhibitors, like anti-PD-1 or anti-PD-L1, are embodiments of that kind of therapy, whose concept revolves around the concept of stopping inhibitory signals that limit the development of antitumour responses. Results obtained from clinical experiences showed that patients responding better to immune checkpoint inhibitors tend to have “hot tumours”, meaning that there are effector components (such as T cells) and the microenvironment supports their function. To make immune checkpoint inhibitors work in those patients with cold tumours, the use of oncolytic adenoviruses could provide the spark to warm them. Viruses are able to trigger the immune alarm and thus, make tumours hot when their replication is restricted to the tumour. To study the potential of oncolytic viruses to increase the efficacy of immune checkpoint inhibitors, an array of preclinical models that allowed to study the matter from different angles were used. While in vivo murine and hamster models provided the basis for direct antitumour effect and survival assessments, other studies including human tumour sample histocultures and other in vitro experiments were performed to understand the subjacent cellular and molecular mechanisms involved. Due to the critical role of the T-cell compartment surrounding the activity of immune checkpoint inhibitors, different virus families were studied in terms of their ability to trigger T-cell responses. The best T-cell engagement was provided by the adenovirus candidate. An adenovirus engineered to support further antitumour immune responses was used to enable anti-PD-1 and anti-PD-L1 therapies. In both cases, the proposed strategy was able to cure all the animals. Additionally, tumours that were already refractory to anti-PD-1 still respond to virotherapy and the virus resets the tumour microenvironment sensitizing those tumours respond to anti-PD-1. Overall, this work revealed the potential of using engineered adenoviruses to repolarize the tumour microenvironment in general and the T-cell compartment in particular to a point that complement the mechanism of action of PD-1 and PD-L1 inhibitory antibodies. That synergistic combination rendered an increased percentage of responses even in tumours previously resistant or refractory to immune checkpoint inhibitors.
  • Nieminen, Anna (Helsingin yliopisto, 2021)
    Gastric cancer (GC) is the fifth most common cancer worldwide and third most common cause of cancer-related deaths. In low-risk countries, such as Finland, most GCs are diagnosed at an advanced stage, which decreases the prognosis. This thesis consists of four studies. In two studies, the aim was to evaluate GC risk in elderly male smokers with atrophic corpus gastritis. The prognostic staging systems Operative Link for Gastritis Assessment (OLGA) and Operative Link on Gastric Intestinal Metaplasia Assessment (OLGIM) were assessed in these patients. We also created a new staging system, Topography, Atrophy, and Intestinal Metaplasia (TAIM), which combines atrophy and IM into one staging. In the third study the aim was to investigate the results of surgical treatment in patients with early gastric cancer (EGC) and to elucidate the extent of lymphadenectomy (D1 vs D2) on morbidity and survival. The aim of the fourth study was to investigate the cyclooxygenase (COX) profile of GC cell lines and the effect of two probiotic bacteria, Lactobacillus acidophilus and Bifidobacterium lactis, on COX expression profile. The patient materials of studies I-II were based on the previous Helsinki Gastritis Study, where 22 346 male smokers were screened for serum pepsinogen I (PGI). 1344 men with low PGI participated. The third study consisted of 94 patients with EGC operated at Helsinki University Hospital between the years 1983 and 2007. The fourth study was performed on primary and metastatic GC cell lines. COX expression profiles were determined by real-time PCR. In study I, 35 (2.6%) men were diagnosed with GC during the follow-up with incidence rate 1.94/1000 patient-years. The standardized incidence rates (SIRs) were calculated for male smokers with low and normal PGI and results were compared to an age-matched general male population (SIR 1.00). Male smokers with normal PGI had SIR 1.13; those with low PGI had SIR 2.43. In study II, OLGIM and TAIM stagings showed prognostic value in evaluating GC risk in men with atrophic corpus gastritis. In the EGC study, the extent of lymphadenectomy did not affect survival, but the risk of complications was higher in D2 operated patients and those with total gastrectomy or pancreatic resection. In the COX study, probiotic bacteria L. acidophilus and B. lactis did not affect COX-2 expression profile. Instead, L. acidophilus upregulated cytoprotective COX-1. Male smokers with atrophic corpus gastritis had an over 2-fold increased GC risk than the general male population. The staging methods OLGIM and TAIM can stratify patients with highest GC risk. Extent of lymphadenectomy did not influence on survival of the patients with EGC. Probiotic bacterium L. acidophilus may possess cytoprotective properties in the gastric mucosa.
  • Kerminen, Sini (Helsingin yliopisto, 2021)
    Population genetics is today an essential part of the studies of human origin and history, as well as of the studies of disease genetics. Populations living apart from each other exhibit genetic variation and this variation between populations is called genetic structure. By studying the genetic structure around the world, it has become possible, for example, to elaborate on the migration patterns of modern humans from the African continent to the rest of the world during the last 100,000 years. In addition, the modern methods of population genetics have enabled a very detailed analysis of genetic structure and population history within single countries, but these methods have not yet been widely utilized in isolated populations such as in Finland. In medical genetics, the genetic background of diseases is routinely analyzed with a genome-wide association study (GWAS). In these studies, it is important to control for the genetic structure of the data appropriately, so that the genetic variation associated with the disease can be reliably distinguished from the general genetic variation associated with the genetic structure. The results of GWAS are used in research to predict the genetic disease risk of an individual using a polygenic score that summarizes the estimated genetic risk over multiple sites of the genome. Because of this summation, even a tiny bias in the GWAS results, due to the genetic structure, can lead to a significant bias in polygenic scores, which, in turn, can lead to incorrect conclusions especially in comparisons between populations. Therefore, understanding the genetic structure and its role in building polygenic scores is exceptionally important to properly understand both the benefits and limitations of polygenic scores in academic research and in future health-care applications. This doctoral thesis examined the fine-scale genetic structure and its role in the geographic distribution of polygenic scores in Finland. The first part of the thesis expanded the understanding of the genetic structure of Finland by determining the geographic border for the major genetic split between East and West Finland, and by identifying 17 previously unreported genetic fine-scale populations. The fine-scale populations were observed to be geographically clustered and to follow Finnish dialect regions. The second part of the thesis utilized the earlier results by building, based on the fine-scale genetic structure, reference groups to estimate the genetic ancestry profile of an individual within Finland. By estimating the genetic ancestry profiles for a set of individuals born between 1923 and 1987, this second study was able to map annual changes in the fine-scale genetic structure within 12 regions. The annual profiles matched well with the migration patterns of Karelian evacuees who were displaced by the war events between 1939 and 1945. The third part of the thesis assessed the role of the genetic split between East and West in the geographic distribution of the genetic risk of five complex diseases (coronary artery disease, rheumatoid arthritis, schizophrenia, ulcerative colitis, and Crohn’s disease) and three quantitative traits (height, body mass index, and waist-hip ratio) using polygenic scores. The third study demonstrated that most of the polygenic scores, that did show geographic variation, mirrored the genetic split between East and West Finland but also revealed bias associated with the genetic structure in Finland. This final study thus demonstrated two main points: first that polygenic scores are susceptible to genetic structure-related biases, even within a relatively homogeneous populations; and second that it is challenging to link population-genetic variation to geographic variation in disease incidence with the current methods. Overall, the results of this doctoral thesis update the current understanding of fine-scale genetic structure in Finland and its changes to meet the needs of modern genetics research. It also demonstrates, both for the scientific community and for the general public, the importance of understanding the genetic structure in the study of both population history and polygenic scores.
  • Peña, Sebastián (Helsingin yliopisto, 2021)
    Harmful alcohol use is a global public health challenge. Socioeconomic differences in alcohol-attributable harm are higher than in all-cause mortality and Finland has one of the highest socioeconomic differences in alcohol-attributable harm in European countries. Lower socioeconomic groups typically experience greater alcohol-attributable harm, despite reporting lower levels of alcohol use. This “alcohol harm paradox” can be the result of differential biases in the measurement of alcohol use, differential vulnerability to the effects of alcohol or reverse causality. What explains the alcohol harm paradox remains largely unknown. This study investigated the existence and patterns of socioeconomic differences in volume of alcohol use and drinking patterns in Finland and Chile (two countries with high alcohol use and harm); examined changes in the prevalence and socioeconomic correlates of alcohol use disorders (AUD) in Finland between 2000 and 2011; and examined whether differential biases in the measurement of volume of alcohol use (using alcohol biomarkers as objective measures of alcohol use) and behavioural risk factors and their joint effects with each other and with socioeconomic status (SES) could explain the alcohol harm paradox. We used data from national health surveys in Finland and also Chile in Sub-study I. The study population were adults residing permanently in Finland. Income and education were used as indicators of SES. Central measurements included alcohol use (volume and heavy episodic drinking), alcohol biomarkers (GGT, CDT, ALT and AST), smoking, body mass index as well as sociodemographic factors. We used structured interviews to assess 12-month and lifetime AUD and linked data from population surveys to mortality data. Outcomes were indicators of alcohol use, 12-month and lifetime prevalence of AUD and alcohol-attributable mortality. Statistical methods included the concentration index, logistic and Cox proportional hazards models and causal mediation analysis. Abstinence was higher among lower socioeconomic groups than in higher socioeconomic groups in Finland and Chile, while heavy episodic drinking was modestly higher among people with lower SES in Finland. Estimated prevalence of 12-month AUD in Finland decreased from 4.6% in 2000 to 2.0% in 2011. We did not find evidence to support the existence of educational differences in AUD in 2000 or 2011. Participants in the lowest income quintile experienced 2.1 times higher risk of alcohol-attributable mortality, despite reporting lower levels of alcohol use. Alcohol biomarkers explained a very small fraction of the socioeconomic differences in alcohol-attributable mortality. We found strong joint (or interactive) effects for SES and alcohol use and SES and smoking. However, smoking, body mass index and their joint effects with income explained a relatively small proportion (18%) of the effect of income on alcohol-attributable mortality. Our findings confirm the existence of the alcohol harm paradox in Finland and support the need for targeted alcohol policies for lower socioeconomic groups and a broader policy agenda for tackling structural determinants of health.
  • Julkunen-Iivari, Anna (Helsingin yliopisto, 2021)
    Chronic periodontitis is an inflammatory disease requiring treatment. Smoking is a significant risk factor for periodontal diseases and many others, including autoimmune diseases and chronic rhinosinusitis. Periodontitis can lead to periodontal-endodontic lesions and may cause chronic rhinosinusitis. To make the right treatment plan for these chronic diseases, diagnosing anatomical structures and pathological signs from radiographs is highly important. This series of investigations focused on several research questions. How does chronic periodontitis associate with autoimmune and autoimmune-related diseases? How does tobacco-product use affect periodontal health? Is tobacco-product use associated with lower education level and mortality? And what kinds of radiologic challenges can be expected when diagnosing radiological signs of periodontitis and anatomical structures in chronic rhinosinusitis patients. Altogether 1 676 randomly selected subjects in Stockholm County, Sweden, joined this study in 1985 and they were followed-up for 30 years for mortality (Studies I and II). Their tobacco use habits and the data from oral examination were recorded at baseline. The Swedish national health registers recorded their hospital and open health-care admissions (World Health Organization [WHO] International statistical classification of diseases and related health problems [ICD] 7, 9 and 10 codes). All subjects were classified into groups: “subjects with autoimmune disease” and “subjects without autoimmune diseases” (Study I); and “current tobacco product users” and “non-users” (Study II). Associations between the diagnosed autoimmune disease and the oral-health variables (Study I), periodontal health parameters, current use of tobacco products, education level and age of death were analyzed (Study II). In study III, the imaging data for 59 randomly selected patients in Helsinki University Hospital, Finland, was used. Radiographical signs of local dentoalveolar bone loss and apical radiolucency were analyzed blinded and inter-imaging accuracy was calculated from computed tomography scans (CT) and panoramic radiographic scans (PTG). Study IV employed the CT data of 57 chronic rhinosinusitis patients from Tampere University Hospital, Finland, to analyze the reproducibility of the Lund-Mackay (LM) scores and 43 other anatomical structures between three professional observers. SPSS was used for all analyses. From the data, 50 patients with diagnosed autoimmune diseases were detected. The plaque index (PI) was significantly higher in the autoimmune disease group compared to non-autoimmune group (≥ median 35 (70%) vs < median 872 (54%), P-value = .030). No statistical difference was found in other periodontal health parameters or use of tobacco products between the groups (Study I). Current tobacco users had poorer periodontal health than non-users. Use of tobacco products associated with higher plaque-, calculus- and gingival index scores compared to non-users (P< .001). They were also more likely to present with deepened periodontal pockets (5 mm) (P< .001) and missing teeth (P = .010) compared with non-users. Tobacco users had lower education level compared with non-users (P< .001), but tobacco-product use did not associate with premature death (Study II). In general, inter-observer agreement in CT and PTG scans with the three other professional observers compared to the oral radiologist was from poor (kappa -0.054) to moderate (kappa 0.455). Based oral-radiologist records, inter-imaging accuracy was moderate (kappa 0.565) to very good (kappa 0.908) (Study III). Between three observers, inter-observer agreement regarding the structures in CT scans was generally moderate by Cohen’s kappa coefficient. Poor reproducibility was observed in the certain surgically important structures, like optic nerve and anterior ethmoidal artery (Study IV). Patients with a higher PI, which characterizes poor oral hygiene, were more likely to develop autoimmune diseases in the long run. Current use of tobacco products has a negative impact on periodontal health parameters and reinforces the perception that tobacco products are risk factors for periodontal diseases. Tobacco-product users are typically less educated than non-users, although, tobacco-product use may not associate with premature death. There is a great variation between professional observers in diagnosing signs of local dentoalveolar bone loss and periapical radiolucency from PTG and CT scans, and anatomical structures in sinus CT scans, which indicates multi-professional consultation before final treatment plan. To diagnose local horizontal bone loss, PTG is as reliable as CT, but not for vertical bone loss or periapical radiolucency.
  • Häkkänen, Paula (Helsingin yliopisto, 2021)
    The objective of this thesis was to analyse obesity screening and treatment practices in school health care, patterns of overweight and obesity development of primary school children, and the associations of psychosocial family- and school-related characteristics to overweight and obesity development. School health care stands crucial for primary prevention of obesity and offers a natural setting for childhood obesity interventions. Yet, screening and treatment of obesity in primary health care has been revealed to be inadequate and prospective longitudinal studies in unselected populations and in Finland are lacking. Additionally, data on childhood obesity consistency, progress and, especially, resolution remain scarce yet are all fundamental for risk evaluation. Furthermore, targeted prevention and treatment of obesity calls for methods for identifying children with potential to develop obesity without natural resolution. The study cohort of this longitudinal retrospective register study consisted of 2000 randomly selected primary school sixth graders aged 12-14 who studied in Helsinki in 2013. Of these, using weight-for-height references, 402 children were affected by overweight at least once since their first grade, 172 by obesity, and 1278 held normal weight over primary school. Electronic health record (EHR) data on growth measurements of the 574 children were manually collected for the study. These were enhanced with the entries of their visits at primary health care and from their pre-seventh grade school health checks. Development of the children’s overweight and obesity during six primary school years was explored by 1) comparing weight categories between early-life and primary school age (Study I), 2) utilising flexible latent class mixed models (LCMM) on body mass index standard deviation score (BMI SDS) to explore groups (latent classes) of children with similar weight development (Study III), and 3) applying Markov multistate models to examine rates of transitioning between BMI SDS categories of normal weight, overweight and obesity (Study IV). Associations of psychosocial family- and school-related factors with weight categories were examined in Study I, and with transition rates in Study IV. School health care personnel’s ability to screen, diagnose and offer overweight-related interventions was analysed in Study II. Whether the actualised interventions were associated with resulting latent classes was investigated in Study III. Obesity started early in primary school and was fairly consistent. The identified overweight trajectories, five for girls and four for boys, converged around age 10, after which only some continued into obesity. Of the yearly transitions from one weight category to another, the highest 1-year probability for girls was staying in overweight category and for boys in obesity category. Compared to children with overweight, a larger fraction of children with obesity had experiences of crises or being bullied or had special needs in studying (Study I). Among girls, transitions into obesity were associated with divorced or single parent families, and decreased resolution from obesity was associated with non-native families (Study IV). Among boys, experiences of crises and being bullied were related to obesity development and to decreased resolution from overweight. Annual nurse assessments actualised well, and school physicians met almost all children with obesity at grade 5 health checks. Of overweight-related extra visits to school physicians, half took place without parents (Study II). Parents accompanied their children at 6% of extra visits to school nurses. Merely a third of the children with obesity received a diagnosis for obesity, even though overweight and obesity were well detected. Overweight-related interventions were mostly offered to children with obesity, less to children of ascendant trajectories (Study III). Typical overweight development patterns, along with their associations with family- and school-related factors, should be noticed when planning individual treatments or health check programs. By doing so, individual treatments could actualise better, and we could benefit more from the limited resources of school health care. Health check programs should be carefully scrutinised, as one of the conclusions of the study points to potential advantages if extensive health checks at 5th grade were actualised earlier or scheduled more flexibly. Working methods, long-term treatment plans, involvement of parents and diagnosis of obesity were found to be areas requiring development and further studies.
  • Suarez Figueiredo, Anna (Helsingin yliopisto, 2021)
    Maternal depression and anxiety during pregnancy may present risks for the developing fetus and offspring lifelong physical and mental health. Exposure to postnatal early life stress (ELS) has also been extensively associated with health problems decades later. According to the Developmental Origins of Health and Disease (DOHaD) hypothesis, environmental factors during pregnancy and early childhood may compromise the development of tissue, organs and systems, such as hypothalamic-pituitary-adrenal (HPA) axis. While the underlying biological mechanisms are not fully understood, epigenetic alterations and genetic vulnerability are the promising biomarkers, which have been suggested to mediate the association of antenatal and early adversity with physical and mental health later in life. The aim of this work was to examine whether exposure to maternal antenatal depression and anxiety was associated with polyepigenetic modifications in their children reflected by the polyepigenetic biomarkers of child’s epigenetic gestational age (GA) and glucocorticoid (GC) exposure score. Additionally, it explored whether these modifications were associated with and mediated the effects of antenatal exposures on child mental health outcomes and whether the associations were moderated by child’s sex. As epigenetic processes undergo age-related changes, the next aim was to study whether epigenetic modifications reflected by the polyepigenetic biomarker of epigenetic clock were associated with physical growth, neuroendocrine functioning, cognition and mental health in adolescents. Finally, this thesis also examined whether genetic variants in FKBP5, the gene that plays a role in the HPA-axis regulation, interacted with exposure to ELS in prediction of type 2 diabetes (T2D), cardiovascular disease (CVD), and quantitative glycemic traits in older adults. The participants for the studies come from three prospective cohorts. Studies I and II capitalize on the Prediction and Prevention of Preeclampsia and Intrauterine Growth Restriction (PREDO) birth cohort. We had full information on genome-wide methylation and genotype from 817 fetal umbilical cord blood samples. In Study I, 694 mothers provided information on their history of depression diagnosed before pregnancy, 581 completed the Center for Epidemiological Studies Depression Scale (CES-D) throughout pregnancy, and 407 completed the Child Behavior Checklist (CBCL) at child’s mean age 3.7 years. DNA methylation (DNAm) GA of fetal cord blood DNA was based on the methylation profile of 148 selected CpG sites. Polyepigenetic biomarker of child’s epigenetic GA was calculated as the arithmetic difference between DNAm GA and chronological GA and adjusted for chronological GA. In Study II, we had information on child diagnoses of mental and behavioral disorders and the number of days the child had been receiving in- or outpatient treatment for these disorders as the primary diagnosis from birth to age 7.1-10.7 years (n=814). Mothers (n=583) reported depressive and anxiety symptoms during pregnancy, using CES-D and State Anxiety Inventory (STAI), respectively. A weighted cross-tissue polyepigenetic GC exposure score was calculated based on the methylation profile of 24 CpGs. Study III was based on the Glycyrrhizin in Licorice (Glaku) cohort. We had information available on DNA samples, physical growth and pubertal development, cognitive abilities, psychiatric problems assessed by mothers with CBCL questionnaire, and saliva samples to estimate cortisol levels for a subsample adolescents at the mean age of 12.3 (n=239). DNAm age was estimated using the Horvath age estimation algorithm. The polyepigenetic biomarker of epigenetic clock was calculated as the unstandardized residual from a linear regression of DNAm age on chronological age and six cell count types. For Study IV, a total of 1,728 Helsinki Birth Cohort Study (HBCS) participants born from 1934 to 1944 were genotyped for FKBP5 SNPs (rs1360780, rs9394309, rs9470080) and were administered a 2-hour (75 g) oral glucose tolerance test (OGTT) and a questionnaire on physician-diagnosed and medication use for chronic diseases at a mean age of 61.5 years. Of them, 273 were exposed to ELS defined as separation from biological parents at a mean age of 4.7 years due to evacuations during World War II. In Study I we found that lower child’s epigenetic GA at birth was significantly associated with maternal history of depression diagnosed before pregnancy and higher antenatal depressive symptoms. It also prospectively predicted child’s total and internalizing problems in early childhood, partially mediating the association of maternal antenatal depression with child internalizing problems, although only in boys. It may signal about their developmental vulnerability to maternal depression during pregnancy (Study I). In Study II we show that while polyepigenetic GC exposure score at birth was not predictive of higher risk for any mental and behavioral disorder in childhood, lower score was associated with more days spent in in- or outpatient treatment for any mental and behavioral disorder as the primary diagnosis. This finding may contribute to better understanding and identification of children at risk for more severe mental and behavioral disorders already at birth (Study II). Next, we demonstrate that adolescents with epigenetic clock age acceleration (AA) displayed more advanced physical growth and development, had higher salivary cortisol upon awakening and higher odds for displaying borderline clinically significant internalizing problems, which may index risk of earlier aging and age-related diseases (Study III). Finally, Study IV revealed that three selected FKBP5 polymorphisms moderated the association of ELS on insulin and glucose values at fasting state and/or during an OGTT in late adulthood, supporting the role of gene-environment interaction and HPA axis dysregulation in the development of metabolic disorders. These study findings provide valuable insights on how the polyepigenetic biomarkers of antenatal adverse exposures and aging and biomarkers of genetic vulnerability in combination with the information about ELS might contribute to early identification of individuals at risk for complex mental and physical disorders enabling timely targeted preventive and therapeutic interventions.
  • Loid, Petra (Helsingin yliopisto, 2021)
    Childhood obesity is a complex disorder affected by genetic, epigenetic and environmental factors. The genetic background and pathogenesis of severe childhood obesity are incompletely understood. Different strategies have been used to elucidate the genetic factors involved in the development of obesity. Recent research on extreme phenotypes has identified several new obesity-related genes and has indicated that rare highly penetrant genetic variants may be involved in the development of severe childhood obesity. This study aimed to identify disease-causing genetic variants in severe childhood- onset obesity using various genetic approaches. We investigated the contribution of rare copy number variants (CNVs) and the rate and spectrum of rare variants in genes involved in the hypothalamic circuit in patients with severe early-onset obesity. We also searched for rare genetic variants in genes involved in pseudohypoparathyroidism and related disorders in patients with severe childhood obesity. A total number of 92 Finnish patients with severe early-onset obesity participated in this study. Hospital records were evaluated, and the patients were clinically examined. 67 normal-weight subjects were used as controls. Several different genetic methods were used, such as array comparative genomic hybridization (aCGH), Multiplex Ligation-dependent Probe Amplification (MLPA), methylation- sensitive MLPA (MS-MLPA), Sanger sequencing, targeted exome sequencing and whole genome sequencing. Additionally, subcutaneous adipose tissue from body mass index (BMI)-discordant siblings from a Swedish cohort was used for the gene expression analyses of candidate genes from the copy number analysis. We identified an enrichment of rare CNVs in subjects with severe childhood obesity (19%) compared to normal-weight controls (3%). Three of the identified CNVs comprised a known syndromic locus (16p11.2 deletion, 1q21.1 deletion and 22q11.21 duplication), five genes (ACE, EFEMP1, MCTP2, PCM1 and SORCS1) in the CNVs had previously been linked to obesity-related disorders and 10 genes (ACP6, ATR, BAZ2B, EFEMP1, KLF15, MACROD2, MAMLD1, MBD5, PCM1 and SORBS1) showed different expression in subcutaneous adipose tissue from BMI-discordant siblings. In targeted exome sequencing and methylation studies, we did not detect any pathogenic defects in the Gsα-cAMP signaling pathway genes GNAS, PRKAR1A and PDE4D. Using targeted exome sequencing, we identified rare (allele frequency <0.5%) pathogenic/likely pathogenic variants in genes involved in the leptin- melanocortin pathway or hypothalamic development in 8% of the subjects. The prevalence of pathogenic variants in MC4R was 2% in our cohort; a novel frameshift deletion in MC4R was found in two unrelated patients. Furthermore, we identified rare heterozygous missense variants in ADCY3, MYT1L, ISL1, LRP2 and a hemizygous missense variant in GRPR, possibly contributing to obesity in these patients. We also report a novel MYT1L frameshift deletion, detected by whole genome sequencing, in a patient with syndromic obesity. The results from our studies suggest a role of rare genetic variants in the hypothalamic circuit in the development of severe childhood obesity. Rare CNVs may also contribute to early-onset obesity. Next generation sequencing and CNV screening are useful tools to identify genetic defects in patients with severe childhood obesity. The findings from our study provide potential candidate genes for further studies. Identification of genetic causes of severe childhood obesity is important, because it can provide new tools for early diagnosis and development of novel treatments targeting specific genetic defects. However, despite extensive genetic studies, no disease-causing genetic aberrations could be identified in the majority of patients with severe early-onset obesity.
  • Ruokolainen, Otto (Helsingin yliopisto, 2021)
    Smoking causes premature mortality and smoking is unevenly distributed across population groups, creating inequalities in health. The lower socioeconomic groups smoke more than the higher socioeconomic groups but the differences in snus use are largely unknown. Detecting the associations and changes in the use of tobacco is essential for targeting and implementing policies to reduce inequalities in health. Another pivotal factor in the success of policymaking is the attitudes of the population towards tobacco control. The current investigation aimed to improve and elaborate the knowledge of socioeconomic differences in tobacco use and factors contributing to the association in the Finnish population. The specific aims of this study were to shed light on the changes in tobacco use and its determinants between socioeconomic groups, to examine the predictors of smoking cessation and to investigate the societal support for tobacco control in the Finnish population. For addressing these issues, several population-based surveys were utilised spanning from the year 1978 to 2017. The number of respondents varied from 945 to 384,379. The main statistical methods in the study included different regression models. Throughout the study, education was used as the indicator for socioeconomic position. The results showed that smoking has declined substantially during the last decades, yet a significant proportion of the adult population still smokes. The less educated smoke more than the highly educated, and the differences between the groups have increased. Among adolescents, a parallel association between socioeconomic position and smoking was observed. Smoking declined in all socioeconomic groups, yet differences between these groups partially increased. Use of snus increased among boys and socioeconomic differences in boys’ snus use were parallel as with smoking but less pronounced. Strong evidence pertaining to widening socioeconomic differences in adolescent snus use was observed. Among the general adult population, higher socioeconomic position was longitudinally associated with smoking cessation, more strongly among men than among women, however. High support for strict tobacco control policies was observed among the Finnish population. Smoking status and demographic variables were strongly associated with acceptance of these policies, non-smokers and women being more supportive than smokers and men. Generally, education was not associated with acceptance of tobacco control. Finnish health policy aims at reducing inequalities in health, and tobacco control policies can be viewed as one of the means to reach this objective. Finnish tobacco control policy has been successful in many respects, for example in decreasing smoking and preventing adolescent smoking initiation. The results from this study indicate that even though smoking has decreased among all socioeconomic groups, tobacco control policies have not been able to eliminate altogether the socioeconomic differences in tobacco use. Thus, future tobacco control policy actions should concentrate on reducing observed differences in tobacco use by socioeconomic groups, in addition to further reducing the overall prevalence.
  • Bergius, Susanne (Helsingin yliopisto, 2021)
    The aim of health care is to maximize health, and in practice, health must be produced in the context of scarce resources. In order to make wise resource allocations, health economic analyses are needed, often in the context of Health Technology Assessment (HTA). Health economic analyses concentrate on assessing the economic value of interventions, whereas full HTA also considers other aspects of decision-making. In recent years, the concept of value-based health care (VBHC) has emerged on the side of traditional health economic analyses. They both try to answer questions concerning the value of interventions in health care - i.e., the relationship of outcomes and investments needed. The objective in VBHC is also to find such actions that can improve the cost-effectiveness of health care dynamically over time. Health-related quality of life (HRQoL) is a patient-reported outcome measure which, in combination with survival data, can produce quality-adjusted life years (QALYs) gained needed as the outcome measure in cost-utility analyses (CUA). This thesis generates real-world data for the use of health economic analyses and compares outcomes of conventional treatment strategies in PC. According to the systematic literature review in this study, preference-based HRQoL data in PC patients are still scarce. HRQoL of PC patients was measured in different stages of the disease (Local, Locally Advanced and Metastatic) and in patients undergoing different treatments with two HRQoL instruments, namely the generic 15D and disease-specific EORTC QLQ-C30. HRQoL data were obtained from 1050 and clinical background data from 1024 patients. The mean age of the patients at baseline was 66.5 years, and most of the patients were in an early stage of the disease as only 59 (6%) of the patients were metastatic at the time of the diagnosis. Even though the mean 15D score of Local and Locally advanced patients did not differ from that of the age-standardized male population, there was a statistically significant difference on the dimensions of depression and distress among all patient groups, which indicates that there are psychological side effects from the awareness of cancer diagnosis. Out of the five functioning scales in the EORTC QLQ-C30 instrument, patients in the Local and Locally advanced groups scored the lowest in emotional function, which can indicate anxiety, worrying, irritation, and/or depression due to the awareness of the diagnosis. The four major treatment strategies during the first year after diagnosis were active surveillance (n=226), radiation (n=280), radical surgery (n=299) and hormonal treatment (n=62). The mean follow-up time in the survival analysis was 77.7 months, and at the end of the follow-up, 84.4% of patients were alive. Median overall survival was 53.8 months (95% CI 44.5 – 63.2 months) in the hormonal group, and median survival for the other groups was not reached. Prostate cancer was a rare cause of death, especially in the active surveillance and surgery groups. The hormonal treatment group had the lowest HRQoL and survival among the studied treatment groups, and consequently, also experienced the least number of QALYs during the two-year follow-up. Outcomes of the three other treatment groups were similar in terms of HRQoL and overall survival, and thus also regarding the number of QALYs experienced.
  • Feodoroff, Maija (Helsingin yliopisto, 2020)
    Background Moderate alcohol consumption is associated with a decreased risk of coronary heart disease (CHD). However, the association between alcohol and microvascular disease entities is less studied and largely unclear. Previous studies have linked smoking with an increased risk of micro- and macrovascular complications in people with type 1 diabetes. However, these studies have often combined current and former smokers and neglect the effect of smoking cessation. In addition, most previous studies have not included dose-dependent measures of smoking. Aims The aim of this thesis was to study the effect of alcohol consumption on the risk of diabetic nephropathy and severe diabetic retinopathy in people with type 1 diabetes. The effect of smoking on the development of diabetic nephropathy, CHD, and stroke was also addressed. In addition, the combined effect of smoking and a known genetic variant on the development of the end-stage renal disease (ESRD) was investigated. Subjects and methods All people included in the study were participants in the ongoing nationwide, multicenter Finnish Diabetic Nephropathy Study (FinnDiane), the aim of which is to identify risk factors of vascular complications in people with type 1 diabetes. This thesis is based on four studies. Study I (n=3608) is cross-sectional in nature and Study II (n=3613), Study III (n=2621), and Study IV (n=4506) are prospective. Information regarding micro- and macrovascular complications is based on data from FinnDiane visits and national data from the Finnish Care Register for Health Care and the Cause of Death Register. Results Compared with light consumers, people who have never consumed alcohol have a higher risk of both diabetic nephropathy and severe diabetic retinopathy. People who have given up using alcohol have the highest risk of diabetic nephropathy and retinopathy. The risk of diabetic nephropathy is increased in spirit-drinking men, and the risk of severe diabetic retinopathy is increased in all spirit drinkers compared with wine drinkers. Compared with never smokers, current smokers have a higher risk of diabetic nephropathy. Former smokers have a similar risk of diabetic nephropathy compared to never smokers. Compared with never smokers, current smokers have an increased risk of CHD, heart failure, and stroke, and former smokers have an increased risk of heart failure in the whole study population and an increased risk of stroke in men. In both current and former smokers, the risk of each cardiovascular event increases with increasing cumulative smoking and increasing intensity of smoking. The rare variant of allele rs4972593, previously known to increase the risk of ESRD in women, is associated with a decreased risk of ESRD in non-smoking men. Conclusions Abstaining from alcohol or previous alcohol consumption and the consumption of spirits are associated with a higher risk of diabetic nephropathy and severe retinopathy. Current smoking is associated with a higher risk of diabetic nephropathy, CHD, heart failure and stroke in a dose-dependent manner. After smoking cessation, the risk of diabetic nephropathy and CHD is decreased and approaches the risk seen in never smokers. However, the risk of heart failure and stroke remains higher in former smokers. Contrary to the previous findings in women, the rare allele rs4972593 seems to have a protective effect in relation to the risk of ESRD in men.

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