Lääketieteellinen tiedekunta


Recent Submissions

  • Kriikku, Pirkko (Helsingin yliopisto, 2015)
    Driving under the influence of drugs (DUID) can adversely affect driving skills in numerous ways and put lives at risk. Legal approaches to DUID vary considerably from country to country, even within Europe, and, in the last decades the emergence of new psychoactive substances (NPS) has further complicated the scene. DUID is an unlawful act if the substance taken is banned or impairs driving. The latter is hard to define and prove, putting pressure on governments to ban NPS as quickly as possible in order to protect the public by facilitating enforcement of DUID laws. However, banning requires knowledge on several aspects of NPS such as prevalence, pharmacology, abuse potential and toxicity. Up-to-date, evidence-based information on NPS is needed by legislators, toxicologists, clinicians, and other health care professionals. Such information would enable potential drug users and the public to be more aware of the risks associated with illicit use of NPS. This study aimed to add to the knowledge of the NPS most relevant in Finland. In this thesis, the prevalence, blood concentrations in drivers and in post-mortem cases, and demographic details of 3,4-methylenedioxypyrovalerone (MDPV) and desoxypipradrol (2-DPMP), were investigated. Changes in prevalence and other characteristics of MDPV were monitored over a time span covering a period before its banning as well as a few years after banning. Phenazepam, a Russian therapeutic benzodiazepine now illegal in Finland, was studied by examining both DUID and post-mortem cases. The use by apprehended drivers of pregabalin, a prescription anticonvulsant with therapeutic indications for neuropathic pain, partial seizures and generalised anxiety disorder, was also studied. The results of this study showed that DUID cases provide a valuable source of information on NPS prevalence and user profiles. However, little specific information could be gained about the impact on driving performance and health risks of NPS mainly due to the fact that NPS were usually used together with a spectrum of other psychoactive substances. It could, however, be concluded that all of the studied NPS were frequently detected in the samples collected from apprehended drivers and, in the case of MDPV, the prevalence changed with time. The number of MDPV-positive cases among apprehended drivers decreased by 51.1% after the drug was banned. The concentrations of NPS found in DUID cases were within the range anticipated to produce significant adverse effects on driving performance, or, in some cases, in the range found in post-mortem cases where the drug may have contributed to the fatality. The presence of the medicinal drug, pregabalin, was found to be connected to abuse rather than appropriate medical use since it was in most cases found in concentrations higher than those recommended for therapeutic use and together with illegal drugs such as amphetamine or cannabis. In post-mortem cases positive for MDPV, the prevalence of suicide was much greater than in fatalities related to other drugs. Three independent registries, namely the DUID toxicology data, the post-mortem toxicology database, and court documents, were examined to gain novel information on the characteristics of NPS use and those abusing them. The large number of cases studied produced information on concentration ranges associated with abuse of the studied substances.
  • Keltanen, Terhi (Helsingin yliopisto, 2015)
    Postmortem (PM) biochemistry is utilized in cause of death (CoD) investigations. The challenges in PM biochemistry are caused mainly by the PM changes. Analytes may be degraded or denatured leading to methodological difficulties. In addition, the re-distribution may cause falsely elevated values when compared to clinical samples. Analytes may also be consumed or produced by microbial metabolism. The sample matrix is often different from that in clinical biochemistry and the reference levels need be obtained through research. The actual death process and agonal period can also lead to unique changes in the analyte concentrations. Despite these challenges, with a sufficient number of samples and adequate research it is possible to optimize biochemical methods for PM samples and obtain reference values for certain conditions. The biochemical results can provide supporting information in cases where the death is caused or associated with metabolic disturbances for instance in diabetes mellitus (DM) or alcohol abuse. Hyperglycemia and ketoacidosis in diabetes can be fatal if not treated. The macroscopical, histological and toxicological findings in autopsy may be scarce or even absent. Determination of vitreous humor (VH) glucose and ketone bodies are very informative in these cases. As ketoacidosis can be present also after heavy alcohol use, the determination of glycemic status prior to death is essential in distinguishing between these two conditions. Glycated hemoglobin (HbA1c) provides information on the glycemic balance in previous weeks. In our studies, we have assessed the results, methods and interpretation provided by analysis of glucose, lactate, ketone bodies, HbA1c and C-reactive protein (CRP) in PM samples. Optimization has been performed in routine casework according to our findings providing more accurate information to the medico-legal pathologists in their CoD investigation work. In addition, our results have provided some insights into the pathology of severe diabetic emergencies as well as to ketoacidosis due to alcohol. According to our results, we recommend that in DM and alcohol abuse related deaths VH glucose, total ketone bodies or beta-hydroxy butyrate and blood HbA1c should always be analyzed. Lactate levels may provide additional information, when the results are interpreted considering the PM interval (PMI). These analyses are recommended also in cases where no suspicion of metabolic disturbances exists, but the findings in autopsy are scarce. The collaboration between the medico-legal pathologists and the laboratory is very important for the development and understanding of PM biochemistry and to include novel analyses to support the CoD investigation. The CoD determination is very important not only on the individual level, but also nationally, since Finnish Statistics collects the CoD data, which can be than further utilized in recommendations concerning health and primary prevention.
  • Luostarinen, Teemu (Helsingin yliopisto, 2015)
    The main goals of neuroanesthesia are to maintain adequate cerebral perfusion pressure (CPP) and, consequently, cerebral blood flow (CBF) to guarantee sufficient oxygenation of the brain and to provide good surgical conditions for the neurosurgeon. This thesis aimed to examine critical aspects of neuroanesthesia with regard to CBF, CPP, blood coagulation, and transfusion of blood products. In our material the requirement of intraoperative blood product transfusion was low during surgery for ruptured arterial aneurysm. Intraoperative red blood cell transfusion (RBCT) seems to be preemptive in nature according to the hemoglobin levels prior to transfusion. RBCT is associated with intraoperative rupture of an aneurysm. Intraoperative RBCT may itself worsen SAH patients neurological outcome. In the event of sudden intraoperative rupture of an aneurysm, adenosine-induced asystole can be used to stop the bleeding and facilitate clipping of the aneurysm. Early infusion of fresh frozen plasma instead of crystalloids should be considered to compensate for expected excess bleeding in neurosurgery to preserve normal coagulation capacity. The potentially less harmful effect of hypertonic saline (HS), relative to mannitol, on blood coagulation may shift the decision towards HS when choosing an optimal solution for treatment of elevated ICP or brain swelling, at least when excess bleeding occurs. However, the clinical relevance of this finding remains unclear and warrants further study. Reliability of end-tidal concentration of carbon dioxide (EtCO2) as an estimate of arterial carbon dioxide partial pressure (PaCO2) after anesthesia induction is not adequate, as seen in the correlation between a decrease in mean arterial pressure and EtCO2-PaCO2 difference in our study. Optimal ventilation after induction of anesthesia should be confirmed by arterial blood gas analysis in patients undergoing neurosurgery to prevent a potentially harmful increase in PaCO2, and consequently, in CBF. Anesthesia in both sitting and prone positions is associated with changes in blood pressure and cardiac function. However, preemptive goal-directed therapy with either Ringer s acetate or hydroxyethyl starch (HES) solutions before positioning enables a stable hemodynamic state during neurosurgery in both positions. The fluid requirement did not differ between the two positions. Slightly less HES is needed to achieve comparable hemodynamics, but is it questionable whether this advantage outweighs the recent concerns regarding colloid safety.
  • Zhang, Yanlei (Helsingin yliopisto, 2015)
    Type 2 diabetes occurs as a consequence of aging, family history, physical inactivity, unhealthy diet and obesity and it is an increasing public health problem worldwide. The condition is associated with high rates of mortality from co-morbid cardiovascular diseases and poor health-related quality of life (HRQoL). A large proportion of individuals with type 2 diabetes are not diagnosed for up to a decade after onset unless a screening programme has been implemented. The estimated prevalence of undiagnosed diabetes in China accounts for about 60-70% of the diabetes population. Diabetes education that is targeted at the general population is the key to increase public knowledge and awareness and is a fundamental building block for addressing the diabetes epidemic. Screening for identifying undiagnosed diabetes could lead to earlier identification and intervention, and postpone or prevent the onset of diabetes and its complications. However, there is a paucity of study on the impact of education and screening programmes on HRQoL, lifestyle modification of the targeted population, and the cost-effectiveness of such programmes. The objectives of this study were to investigate 1) the cost and effectiveness of a population-based education programme to increase public knowledge and awareness of diabetes; 2) the cost-effectiveness of two different screening tools for undiagnosed diabetes; 3) impact of type 2 diabetes and its complications on individuals HRQoL; 4) impact of a screening programme on individuals overall HRQoL, depression dimension and lifestyle modification. This study was based on data analyses of two population-based diabetes surveys conducted in 2006 (Survey A) and 2009 (Survey C), and a dataset of diabetes high-risk population identified through the Qingdao Diabetes Prevention Program (QD-DPP) between 2007 and 2010 in Qingdao, China (Survey B). The same stratified, random cluster sampling method was used in Surveys A and C to recruit a representative sample of the general population who had lived in Qingdao city for at least five years. A total of 5355 individuals in Survey A and 5110 in Survey C aged 35-74 years participated in the surveys. A total of 3108 rural participants who did not have diabetes at baseline in 2009 were invited for a re-examination and 1782 individuals attended the follow-up survey. A standard 2h 75g oral glucose tolerance test was administrated to all participants in both surveys. Diabetes education and health promotion information and activities under the framework of QD-DPP were given via printed and audio-visual media, the internet, free distribution of information booklets and diabetes risk score (DRS) flyers that targeted the entire population of 1.94 million who lived in the intervention areas. An adult with a DRS more or as much as 14 was considered at high-risk for diabetes and invited to a nearby community clinic for a free capillary blood glucose test. The proportions of participants who correctly marked obesity, physical inactivity and positive family history of diabetes as the risk factors of diabetes were doubled in both urban and rural populations, irrespective of age and gender during the QD-DPP education campaign period. The cheapest way to inform 1000 individuals about type 2 diabetes was to distribute DRS flyers (¥54, ¥ = Chinese yuan), followed by the newspapers articles (¥77), booklets (¥313) and by radio programmes (¥375) (1 ≈7¥, for the year 2015). The fasting capillary glucose (FCG) test and Chinese DRS questionnaire were used as the first-line screening tools and these were evaluated for detecting undiagnosed diabetes in primary care settings. The sensitivity of FCG and DRS was 65.1% and 65.8%, whereas their respective specificity was 72.4% and 55.2%. The costs per undiagnosed diabetes identified at the optimal cut-off values of 6.1 mmol/l for FCG and 14 for DRS were ¥674 and ¥844, respectively. The area under curve (AUC) was higher for FCG than for DRS (75.3% vs. 63.7%, p less than 0.001). People with previously known type 2 diabetes reported that the symptomatic comorbidities had a strong negative impact on HRQoL; no significant difference was detected between people without diabetes and with newly diagnosed diabetes. The screening and labelling as pre-diabetes or normoglycaemia had no adverse impact on the participants overall HRQoL and depression. An improvement in lifestyle as measured by the frequency of physical activity and vegetable intake was observed at 3 years post screening in both groups. In conclusion, the QD-DPP education campaign efficiently increased public knowledge and awareness of diabetes. The DRS questionnaire is a simple, non-invasive and reliable first-line screening tool to identify undiagnosed diabetes at primary care settings. The diabetes screening programme in Qingdao generated positive changes towards a healthy lifestyle and did not result in any harm to the participants.
  • Demir, And (Helsingin yliopisto, 2015)
    This study was undertaken to assess the feasibility of non-invasive sampling and assay of urinary gonadotropins for clinical evaluation of pubertal development. In the first study, the concentrations of LH and FSH in concurrent serum and first-morning-voided (FMV) urine samples of 820 children (486 boys and 334 girls, age 0-17 years) were determined with time-resolved immunofluorometric assay (IFMA). The detection limit of IFMA was 0.018 IU/L for FSH, 0.015 IU/L for LH and 0.012 IU/L for LHspec. It was possible to measure the low prepubertal LH and FSH concentrations reliably in these samples due to the high sensitivity and low detection limits of IFMA. The correlation between serum and urinary gonadotropin values was high (r=0.751; p < 0.001 for FSH and r=0.720; p < 0.001 for LH), and the urinary and serum concentrations were close to each other. Correcting urinary gonadotropin concentrations on the basis of urinary density or creatinine did not improve the correlation. Age-related changes in urinary LH and FSH (U-LH and U-FSH) were examined. The concentrations of U-LH and U-FSH decreased from birth until the child was a few months old, after which the upper range of the U-LH levels of girls remained stable at below 0.5 IU/L until age 9 years and of boys below 1.0 IU/L until age 11 years. The upper range of the U-FSH levels of girls remained below 3.0 IU/L until age 10 years and of boys below the same concentration until age 12 years. The median U-LH concentration during the prepubertal period was about 0.06 for girls and 0.07 for boys. For the boys, this figure rose 10-fold by age 11, 40-fold by age 12 and 50-fold by age 13-14. The overall increase in the median U-LH concentrations was 75-fold from 5 to 15 years and 35-fold from Tanner stage G1 to G5. The corresponding figures for girls were 30-fold by age 11, 70-fold by age 12 and 90-fold by age 14; the overall increase in median U-LH concentrations was 90-fold from 5 to 15 years and 40-fold from Tanner stage B1 to B5 times. These finding indicate that the U-LH concentrations of FMV samples obtained from clinically prepubertal children reflect pubertal levels. The age-related changes in U-FSH concentrations were similar for boys and girls; the only difference was that the levels were generally higher for girls, in particular between ages 2 8 years. U-FSH reached a 5-fold level compared to prepubertal levels by the end of the puberty in both sexes. FMV U-LH, U-FSH and their ratios correlated well with the corresponding basal and GnRH-stimulated serum concentrations (P < 0.001). Receiver operating characteristic (ROC) curve analyses of urinary and serum LH and FSH concentrations showed that FMV U-LH and U-LH/U-FSH performed equally well as the GnRH test for differentiating early puberty (Tanner 2) from prepuberty (Tanner 1) [area under the curve (AUC) 0.768-0.890 vs. 0.712-0.858]. FMV U-LH and U-LH/U-FSH performed equally well as basal S-LH for predicting a pubertal GnRH test result (AUCs 0.90 0.93). Among the tests studied, only FMV U-LH differentiated the transitions from Tanner stage 1 to 2 and Tanner stage 2 to 3 (p < 0.001 for boys and p-0.003 for girls). Again, this corroborates that FMV U-LH is the most reliable tool for evaluation of pubertal development. Therefore, FMV urinary LH determinations, which are non-invasive and, at most, minimally stressful for the child patient, can be used for preliminary diagnostic evaluation of pubertal development. It reduces the need for S-LH determinations and the GnRH stimulation tests, both invasive procedures.
  • Ahmed Haji Omar, Abdirisak (Helsingin yliopisto, 2015)
    Oral (OSCC) and cutaneous (CSCC) squamous cell carcinomas are epithelial neoplasms, which are both derived from keratinocyte cells. However, the etiology and prognosis of OSCC and CSCC are different. Main etiological factors behind OSCC are tobacco smoke and alcohol consumption, and for CSCC the UV-radiation. OSCC has poorer prognosis than CSCC. In order to be invasive, cancer cells have to pass various barriers. They have to disrupt cell-to-cell junctions, penetrate basement membrane, and invade connective tissue. The pattern of invasion of tumors varies strikingly. Some invade in large border fronts while others invade in single cell manner. Expression of transmembrane proteins E-cadherin and Syndecan-1 in cell membrane are lost during tumor invasion, and therefore loosening cell adhesion. Matrix metalloproteinases (MMP) are tissue proteinases, which have proteolytic role in various physiological events and during tumor progression MMPs are capable of degrading extracellular matrix (ECM) proteins but have also immunomodulatory role. Toll-like receptors (TLRs) are part of innate immunity and can recognize exogenous pathogen associated molecular patterns or endogenous damage associated molecular patterns. Cancer cells may use TLRs to induce tumor promoting inflammation. The aim of the study was to examine possible cellular and molecular differences between OSCC and CSCC explaining their different behaviors as cancers despite cellular similarities. The study included 36 OSCC and 27 CSCCs from patients with early stage tumors. The over-all and disease-specific survival was retrospectively evaluated with histological risk assessment (HRA) model and histological risk assessment score (HRS). We performed immunohistochemical staining for E-cadherin, Snail (Snail1), Syndecans (1 and 2), MMPs (7, 8 and 9) and TLRs (4 and 5). In vitro, with oral and cutaneous cell lines the effect of TLR-5 ligand flagellin on proliferation, migration and invasion was studied. OSCC patients had worse disease-specific survival than CSCC patients and it correlated with invasion depths of the OSCC tumors. OSCC had more severe histological pattern of invasion than CSCC. E-cadherin and Syndecan-1 expression decreased in the invasive front of OSCCs and CSCCs. Syndecan-1 expression in the tumor stroma was higher in OSCC than in CSCC in tumors with invasion depth over 4 mm. MMP-7 was mainly expressed in the invasive front of OSCC and CSCC and was stronger in OSCC than in CSCC. MMP-8 and MMP-9 were mainly expressed in the peritumoral inflammatory cells. TLR-5 expression was stronger in OSCC than in CSCC. In vitro, TLR-5 ligand flagellin increased proliferation, migration and invasion of less aggressive oral and cutaneous cell lines, but failed to do so with the most aggressive oral cancer cell line. As a conclusion, OSCC patients of this study had poorer disease specific survival than CSCC patients. Increased stromal syndecan-1 expression in OSCC, MMP-7 expression in the invasive front of tumor, and MMP-9 expression in inflammatory cells could partly explain the difference in survival between OSCC and CSCC.
  • Helenius, Mikko (Helsingin yliopisto, 2015)
    Irreversible vascular remodeling has a central role in a variety of pathophysiological conditions including pulmonary arterial hypertension (PAH). Hypoxia and inflammation are prominent features in PAH, along with hyperplasia and hypertrophy of vessel wall layers. Although, endothelial cell (EC) dysfunction is thought to drive the multiple forms of vascular remodeling, the origins of this phenomenon are poorly understood. Extracellular ATP and its metabolites are important regulators of vascular tone, permeability, and homeostasis. Yet little is known about their role in pathological vascular remodeling. By using chronic hypoxia and PAH animal models as well as human PAH patient samples, this study was undertaken to evaluate the catalytic activities and expression levels of nucleoside triphosphate diphosphohydrolase-1 (NTPDase1, otherwise known as CD39) and other purine-converting ectoenzymes with a primary focus on vascular EC. For this purpose we employed thin-layer chromatographic enzyme assays with 3H-labelled nucleotide substrates, in combination with various immunoassays and qPCR. In addition we have developed a highly sensitive assay for simultaneous sensing of extracellular ATP and its metabolites and also a novel method for measuring CD39 activity in modeled to in vivo conditions. In functional assays, cells or animals were stimulated through purine signaling pathways and proliferation, apoptosis, permeability, and DNA damage were assayed. Our results clearly demonstrated that the activity of CD39 was downregulated in chronic hypoxia, monocrotaline induced animal models of PAH and in human PAH patients. Attenuated enzyme activities could create a niche in the vasculature where ATP levels were increased and adenosine levels were decreased. Even a small increase in ATP concentration was enough to induce an apoptosis-resistant, hyper-proliferative, and DNA-damageresistant phenotype in ECs of pulmonary origin. The observed effects were at least partly dependent on P2Y11 receptor activation. In addition, we found that low ATP concentrations could induce pulmonary smooth muscle cell proliferation and migration. Interestingly, we found that small apelin peptide could directly restore the downregulated CD39 activity. This study implies that purinergic signaling, ATP mediated cell activation in particular, plays a truly significant role in pathological vascular remodeling, and that it could be used as a therapeutic target. Moreover, purinergic signaling pathways could be used before vascular injury to precondition EC against irradiation or chemotherapy induced DNA damage.
  • Pemovska, Tea (Helsingin yliopisto, 2015)
    Adult acute myeloid leukemia (AML) effectively illustrates the challenges of contemporary cancer drug discovery and development, as molecularly targeted therapies have not yet been translated in clinical practice. In fact the standard therapy (cytarabine and an anthracycline) for AML has not been changed in over 40 years. As a consequence, outcome remains poor with overall survival of 30-40%. The genetic alterations that are associated with AML have been mapped, but the underlying disease mechanism is poorly defined due to large inter-patient heterogeneity. In contrast, chronic myeloid leukemia (CML) is strictly driven by BCR-ABL1 and drugs targeting the ABL1 kinase activity have paved the way for oncoprotein targeting drugs in the treatment of cancer. In CML the main clinical challenge is instead the emergence of resistance to ABL1-directed therapy. This resistance typically occurs through point mutations in the kinase domain of ABL1 such as the clinically challenging T315I mutation. Hence, in both leukemia types there is an unmet need for novel therapeutic strategies. This study focused on development and implementation of an Individualized Systems Medicine (ISM) platform to identify novel therapeutic strategies for leukemia patients. The ISM strategy incorporated functional ex vivo drug sensitivity and resistance testing (DSRT), deep molecular profiling and clinical information to facilitate identification of personalized therapy approaches. A large number of approved and investigational anti-cancer compounds were tested and individualized selective responses were quantified with drug sensitivity scores (DSS). RNA and exome sequencing data was used to identify genetic alterations that enabled associating drug sensitivities with genetic alterations and biomarkers. The DSRT approach enabled functional taxonomy of AML patient samples based on drug responses, provided insights into disease biology, and identified effective drugs and drug combinations for individual patients and thus facilitated drug repurposing. In addition, integration of DSRT and molecular data identified phenotype to genotype links that has a potential for rapid translation of results. Clinical implementation of ISM data was plausible in approximately 80% of relapsed and refractory AML patient cases, and meaningful and evaluable responses were achieved in approximately 40% of cases. Notably, emergence of in vivo resistance to targeted therapy was mirrored in the DSRT profile of the relapsed samples, highlighting a solid correlation between ex vivo and in vivo drug responses. Finally, this study identified a number of kinase inhibitors that can be repositioned for specific subtypes of AML and CML, such as dasatinib in combination with a FLT3 inhibitor for AML patients with FLT3-ITD mutations and axitinib for patients with BCR-ABL1(T315I)-driven leukemia. The results of this thesis demonstrate how unbiased drug sensitivity profiling of patient-derived cancer cells is a powerful way to discern unforeseen drug-disease and drug-target links with clinical implications and provides a workable concept that can be implemented in routine clinical care of cancer patients in the future.
  • Vattulainen-Collanus, Sanna (Helsingin yliopisto, 2015)
    Pulmonary arterial hypertension (PAH) is one of the most severe vascular diseases. In addition to increased vasoconstriction there are significant histopathological changes in small pulmonary arteries of PAH patients. These histopathological changes include endothelial cell (EC) injury, vascular inflammation, medial hypertrophy, intimal hyperplasia, and plexogenic arteriopathy. Changes in EC phenotype are suggested to play an important role in the development of occlusive vascular lesions. This phenotypic switch involves apoptosis-resistance, hyperproliferative capacity, and changes in energy metabolism. Somatic genomic abnormalities have also been identified in vascular lesions from patients with PAH. Mutations in bone morphogenetic protein receptor 2 (BMPR2) have been tightly linked to the pathogenesis of PAH. The genetic landscape of PAH-associated mutations in Finnish population is poorly understood. In this study, we utilized a novel targeted next-generation sequencing approach called Oligonucleotide-Selective sequencing (OS-Seq) to evaluate the role of known PAH genes, confirming a relatively high incidence of BMPR2 mutations among analyzed Finnish PAH-patients. Pulmonary ECs from the patients with PAH are identified with severe somatic chromosomal abnormalities. The role of genomic instability during pathogenesis of PAH and the mechanisms behind these changes in ECs are yet unknown. The genomic instability in IPAH patient ECs and the occlusive vasculopathy resemble a neoplastic process. In this study we revealed that loss of BMPR2 in pulmonary ECs leads to increased susceptibility to DNA damage and establish a link between Breast cancer 1 and BMPR2. BMPR2 deficiency-associated loss of DNA damage control could play a role in PAH -associated EC dysfunction, genomic instability and altered cellular phenotypes. One of the critical transcription factors downstream of BMPR2 is peroxisome proliferator-activated receptor gamma (PPARγ). In mice the TIE2 promoter mediated EC-specific loss of functional PPARγ (TIE2CrePPARγflox/flox) leads to dysregulation of EC genes such as apelin and development of PAH. The role of PPARγ in vascular regeneration or angiogenesis has remained poorly understood. We show that dysfunctional PPARγ in ECs leads to attenuation of angiogenic capacity and migration defect. Purinergic signaling is one potential modulator of pulmonary vascular homeostasis. ATP is known to regulate a variety of cellular processes, including vascular remodeling. In response to cell damage, ATP is released into extracellular space and through several physiological mechanisms cells can regulate their basal ATP niche contributing to the growth and microenvironment of the cells. The role of ATP in vascular modulation is well-known yet its association with pathophysiology of PAH is still undefined. In ECs the CD39 enzyme is the most prominent ATP hydrolyzing enzyme. We showed that PAH patients manifest suppression of CD39 leading to excess ATP niche in vascular wall. Our results suggest that attenuated CD39 activity is tightly linked to vascular remodelling and phenotypic switch of ECs.
  • Almangush, Alhadi (Helsingin yliopisto, 2015)
    Histopathological predictors of early stage oral tongue cancer Oral tongue cancer constitutes the majority of malignancies of the oral cavity. In Finland during 2013, the age-adjusted incidence rates of oral tongue cancer were 1.7 per 100,000 in males and 0.8 per 100,000 in females. Staging of the clinical status of tumor size, lymph node, and metastasis (cTNM staging) is a widely accepted system for classification of many cancers including oral squamous cell carcinoma (OSCC). However, this staging system failed to prognosticate the outcome of early stage oral tongue squamous cell carcinoma (OTSCC). Numerous studies designed to introduce prognostic parameters and/or models to complement the insufficiency of cTNM staging and to predict the patient outcome have been carried out. Many of these prognostic models (or systems) were based on histopathologic parameters. However, all of the previously introduced models showed little or no predictive power in early stage (cT1-2N0) OTSCC. Thus, the identification of markers that predict the outcome of patients with early stage OTSCC is still necessary in order to apply effective individualized treatment. In this international collaborative study, we have examined the prognostic impact of several predictive factors in large patient cohorts from 7 institutions located in 3 geographic regions (Finland, Brazil, and USA). Moreover, we have introduced a new simple predictive model (BD score) for histopathologic classification and prognostication of early OTSCC. We suggest that this model could possibly be easily applied during the surgical resection, so patients with aggressive OTSCC could benefit from elective neck dissection (END) during the same procedure. This model could offer a step forward toward the personalized management of OTSCC. However, additional validation in different patient cohorts is still required.
  • Laitakari, Elina (Helsingin yliopisto, 2015)
    Background: In recent decades, the total number of burn injuries has decreased globally, while the number of childhood burns has been increasing. Infant burn victims are a specific group because they are highly dependent on parents or caregivers. Aim of the study: The aim of this study was to clarify special characteristics and clinical outcome of infant burns. The purpose of this study was to determine the incidence and trends of inpatient and outpatient treatments for burn-injured infants. Patients and methods: Burn victims younger than 1 year born 1990 2010 were identified from the National Institute of Health and Welfare (THL) and the Statistics Finland registers. The analysis consisted of the incidence of burn injury, trends of treatment, and risk factors for burns. Between 2005 and 2009 126 burn victims aged less than 1 year were treated in the Children s Hospital, Helsinki, Finland. Hospital electronic databases were searched to clarify detailed information and patients treated as inpatients and outpatients were analyzed separately. The HRQoL of the 126 burn-injured children was evaluated with a validated, standardized 17D questionnaire 5 to 9 years after the burn injury. Results: Between 1990 and 2011, 1842 infant burn victims were treated at Finnish hospitals. The annual overall incidence per 1000 persons rose from 0.77 to 2.04, and the incidence of outpatient-treated burns increased from 1.11 to 1.67. Based on the analysis, the risk factors for infant burn injuries are male gender, being firstborn, the mother s young age, and low socioeconomic status. During the 5-year study period 20 burn injured infants were treated as inpatients and 106 as outpatients in the Children s Hospital. Girls outnumbered boys in the inpatient-treated group, and 45% were younger than 6 months. The final mean TBSA was 8.5% (from 0.5 to 40%). In the outpatient group, 52% were boys, and 57% were aged 9 to 12 months. The final mean TBSA burned was 1.4% (range from 0.5 to 7%). Caregiver eyewitnessed the accident in 66% of the cases, and 44% of the burns were on the hands. Most burns occurred at home, and two thirds of the burns were scalds caused by hot liquids. The respondents (n=44, 35%) appeared not to suffer from long-term consequences of the burn injury, and the respondents and non-respondents proved to be similar in terms of age, injury severity, and treatment given. Conclusions: The number of infant burns increased in Finland during the study period. Two thirds of infant burns were scalds caused by hot liquids, and most of these were preventable. Firstborn boys aged 9 to 12 months of young mothers with low socioeconomic status are at greater risk for burn injuries. The long-term HRQoL of burn-injured children was comparable to that of the controls.
  • Manninen, Otto (Helsingin yliopisto, 2015)
    Unverricht-Lundborg type progressive myoclonus epilepsy (EPM1, OMIM 254800) is an autosomal recessive disorder characterized by onset at the age of 6 to 16 years, incapacitating stimulus-sensitive myoclonus and tonic-clonic epileptic seizures. It is caused by mutations in the gene encoding cystatin B (CSTB). However, the disease processes leading to the observed symptoms are currently unclear. Clinical magnetic resonance imaging (MRI) of the brain has shown neurodegenerative changes and computed tomography data have suggested a bone phenotype. This thesis examined the disease processes and the background of the pathological changes in the brain and the bone, utilizing modern imaging methods and image analysis methodology complemented with experimental data in the mouse model (the Cstb -/- mouse) of the disease. In order to gain a comprehensive picture of the disease progression in the brain, we performed a longitudinal imaging study in the Cstb -/- mouse. Animals were studied from the pre-symptomatic to fully symptomatic disease stages (1-6 mo). For studying atrophic changes, in vivo MRI volumetry was preformed once a month from 1 to 6 months of age. For investigating white matter (WM) changes, ex vivo diffusion tensor imaging (DTI) was performed at 2, 4 and 6 months. The fractional anisotropy (FA) maps derived from DTI data were analysed using track based spatial statistics (TBSS) that provided us with a hypothesis-free analysis of white matter changes. In vivo volumetry showed progressive volume loss in Cstb-/- mice over time, the rate of which was neither spatially nor temporally uniform over the brain. TBSS revealed progressing FA decrease, suggesting severe and widespread WM damage, with most drastic changes in the cerebellum and the thalamus. Subsequently the congruence of the observed WM changes between the mouse model and EPM1 patients were evaluated. In vivo DTI data from fully symptomatic adult patients and ex vivo data from fully symptomatic (6 mo) Cstb-/- mice were analysed using TBSS with matching protocols. The results revealed extensive changes with a pattern of chronic WM degeneration in EPM1 patients, with similar alterations detected in Cstb-/- mice. Furthermore, previously unknown brain regions were shown to be affected both in patients and in mice. The imaging data were then used to guide tissue level analyses in mice. The microstructural counterpart of the areas with decreased FA in mice was characterized by immunohistochemistry and transmission electron microscopy. Based on the tissue level findings, the extensive changes identified by DTI in both EPM1 patients and in Cstb-/- mice are probably a consequence of widespread WM loss upon axonal degeneration, and likely contribute to the motor disturbances present in the disease. Finally, we characterized the bone changes underlying the observed skeletal phenotype in EPM1 patients by performing microtomography (µCT), histology, and in vitro cell culture experiments with the Cstb-/- mouse. Analysis of bone microstructure in Cstb-/- mice using μCT revealed structural changes. Moreover, histology confirmed both structural and functional alterations. The basis of these findings was investigated by studying the functionality of bone resorbing osteoclasts differentiated in vitro from bone marrow. In resorption pit formation assays, less and smaller resorption pits were formed by Cstb-/- osteoclasts, indicating decreased resorptive capacity, likely due to a decrease in osteoclast numbers. These data imply that the skeletal changes in Cstb-/- mice and EPM1 patients are a result of CSTB deficiency leading to altered osteoclast function, and the results would indicate that CSTB has a more substantial role as a modulator of bone metabolism than previously thought. Our results showed high correlations of the atrophy, WM and bone phenotypes between EPM1 patients and Cstb-/- mice and provided information about brain and tissue level changes present in these pathologies. High correlation between the mouse model and the findings in patients provided further affirmation for the use of the mouse model in EPM1 research. Furthermore, the results provided new insight both into the progression of brain pathology and the processes underlying the bone changes present in the disease. Finally, our research introduced new methodologies for research in mouse models of neurodegenerative diseases, and raised the prospects of future research.
  • Medvedovsky, Mordekhay (Helsingin yliopisto, 2015)
    During the last years magnetoencephalography (MEG), has become an important part of the pre-surgical epilepsy workup. Interictal activity is usually recorded. Nevertheless, the technological advances now enable ictal MEG recordings as well. The records of 26 pharmaco-resistant focal epilepsy patients, who underwent ictal MEG and epilepsy surgery, were reviewed. In 12 patients prediction of ictal onset zone (IOZ) localization by ictal and interictal MEG was compared with ictal intracranial EEG (icEEG). On the lobar surface level the sensitivity of ictal MEG in IOZ location was 0.71 and the specificity 0.73. The sensitivity of the interictal MEG was 0.40 and specificity 0.77. The records of 34 operated epilepsy patients with focal cortical dysplasia (FCD) were retrospectively evaluated. The resected proportion of the source cluster related to interictal MEG was evaluated in respect to postoperative seizure outcome. 17 out of 34 patients with FCD (50%) achieved seizure freedom. The seizure outcome was similar in patients with MR-invisible and MR-visible FCD. With MEG source clusters and favorable seizure outcome (Engel class I and II) the proportion of the cluster volume resection was 49% - significantly higher (p=0.02) than with MEG clusters but unfavorable outcome (5.5% of cluster volume resection). Median nerve somatosensory evoked MEG responses were processed by movement compensation based on signal space separation (MC-SSS) and on spatio-temporal signal space separation (MC-tSSS). MEG was recorded in standard and deviant head positions. With up to 5 cm head displacement, MC-SSS decreased the mean localization error from 3.97 to 2.13 cm, but increased noise of planar gradiometers from 3.4 to 5.3 fT/cm. MC-tSSS reduced noise from 3.4 to 2.8 fT/cm and reduced the mean localization error from 3.91 to 0.89 cm. The MEG data containing speech-related artifacts and data containing alpha rhythm were processed by tSSS with different correlation limits. The speech artifact was progressively suppressed with the decreasing tSSS correlation limit. The optimal artifact suppression was achieved at correlation of 0.8. The randomly distributed source current (RDCS), and auditory and somatosensory evoked fields (AEFs and SEFs) were simulated. The information was calculated employing Shannon's theory of communication for a standard 306-sensor MEG device and for a virtual MEG helmet (VMH), which was constructed based on simulated MEG measurements in different head positions. With the simulation of 360 recorded events using RDCS model the maximum Shannon's number was 989 for single head position in standard MEG array and 1272 in VMH (28.6% additional information). With AEFs the additional contribution of VMH was 12.6% and with SEFs only 1.1%. To conclude, ictal MEG predicts IOZ location with higher sensitivity than interictal MEG. Resection of larger proportion of the MEG source cluster in patients with FCD is associated with a better seizure outcome, however, complete resection of MEG source cluster is often not required for achievement of favorable seizure outcome. The seizure outcome is similar in patients having MR-positive and MR-negative FCD. MC-tSSS decreases the source localization error to less than 1 cm, when the head is displaced up to 5 cm; however, it is reasonable to limit use of movement compensation for no more than 3-cm head displacement to keep the head inside sensor helmet. The optimization of the tSSS correlation limit to about 0.8 can improve the artifact suppression in MEG without substantial change of brain signals. MEG recording of the same brain activity in different head positions with subsequent construction of VMH can improve the information content of the data.
  • 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.
  • Markula-Patjas, Kati (Helsingin yliopisto, 2015)
    Children with juvenile idiopathic arthritis (JIA) are predisposed to compromised bone health and alterations in body composition because of chronic inflammation, nutritional and hormonal disturbances, limited physical activity and glucocorticoid (GC) therapy. Compromised bone health may present as pathological vertebral compression fractures, but data on their prevalence and risk factors in children are limited. Excess fat, and especially adipose tissue-derived adipokines leptin and adiponectin, may also contribute to impaired bone health. Furthermore, adipokines modulate immunity and inflammation in adults with rheumatic diseases, but their role in JIA has not been explored. We evaluated bone health in patients with severe JIA and investigated body composition and adipokines and their contribution to bone health and disease activity in JIA. We recruited two cohorts of patients for cross-sectional studies. The Severe JIA Cohort comprised 50 patients with severe polyarticular or systemic JIA. The GC-treated Cohort included 50 patients with JIA with mostly mild to moderate disease severity and at least three months' exposure to systemic GC. The results were compared with those of sex-and age-matched healthy controls. The study protocol included clinical and laboratory assessments, evaluation of bone mineral density (BMD) and body composition by dual-energy X-ray absorptiometry (DXA), spinal radiography and spinal magnetic resonance imaging (MRI). Spinal radiography showed vertebral compression fractures in 22% of the patients with severe JIA. Patients with fractures had higher weight-adjusted cumulative GC dose, higher disease activity and higher body mass index than those without fractures. Bone age-corrected BMD Z-scores for lumbar spine and whole body were similar between those with and without fractures. On spinal MRI, altogether 28% of patients with severe JIA showed vertebral fractures and several other vertebral changes, including end plate irregularities in 26%, anterior vertebral corner lesions in 16% and disc changes in 46%. Based on concentrations of bone turnover markers, the patients with severe JIA had increased bone resorption, but normal bone formation. Further, patients with severe JIA had increased body adiposity, and their serum leptin was increased even independently of fat mass. Leptin showed an inverse association with bone turnover markers in patients, while in controls the association was dependent on fat mass. In the GC-treated Cohort, fat mass, lean mass and serum leptin and adiponectin were similar to those of controls, but patients had slightly lower BMD values than controls. Those patients with lumbar spine BMD Z-score -1.0 tended to have higher serum leptin values than those with higher BMD Z-scores, but in regression analysis leptin was not associated with BMD. Adipokines did not correlate with current disease activity in either patient cohort. Patients with severe JIA have compromised bone health based on high prevalence of compression fractures. Risk factors include high GC exposure, high disease activity and high body mass index. BMD, as measured by DXA, is unable to differentiate between those with and without compression fractures. According to spinal MRI findings, patients with severe JIA have, besides compression fractures, several other changes involving intervertebral discs and vertebral end plates; the clinical relevance of these remains uncertain. Patients with severe JIA are prone to high adiposity, whereas those with less severe disease have normal body composition despite previous GC exposure. Leptin may negatively contribute to bone metabolism in severe JIA, but larger and longitudinal studies are needed to prove causality and to evaluate whether these preliminary findings are generalizable to other JIA groups. We did not observe a correlation between leptin or adiponectin and disease activity in either JIA cohort. The possible role of adipokines as a modulator of immunity and inflammation in JIA remains to be evaluated.