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  • Förster, Johannes G (Helsingin yliopisto, 2008)
    Continuous epidural analgesia (CEA) and continuous spinal postoperative analgesia (CSPA) provided by a mixture of local anaesthetic and opioid are widely used for postoperative pain relief. E.g., with the introduction of so-called microcatheters, CSPA found its way particularly in orthopaedic surgery. These techniques, however, may be associated with dose-dependent side-effects as hypotension, weakness in the legs, and nausea and vomiting. At times, they may fail to offer sufficient analgesia, e.g., because of a misplaced catheter. The correct position of an epidural catheter might be confirmed by the supposedly easy and reliable epidural stimulation test (EST). The aims of this thesis were to determine a) whether the efficacy, tolerability, and reliability of CEA might be improved by adding the α2-adrenergic agonists adrenaline and clonidine to CEA, and by the repeated use of EST during CEA; and, b) the feasibility of CSPA given through a microcatheter after vascular surgery. Studies I IV were double-blinded, randomized, and controlled trials; Study V was of a diagnostic, prospective nature. Patients underwent arterial bypass surgery of the legs (I, n=50; IV, n=46), total knee arthroplasty (II, n=70; III, n=72), and abdominal surgery or thoracotomy (V, n=30). Postoperative lumbar CEA consisted of regular mixtures of ropivacaine and fentanyl either without or with adrenaline (2 µg/ml (I) and 4 µg/ml (II)) and clonidine (2 µg/ml (III)). CSPA (IV) was given through a microcatheter (28G) and contained either ropivacaine (max. 2 mg/h) or a mixture of ropivacaine (max. 1 mg/h) and morphine (max. 8 µg/h). Epidural catheter tip position (V) was evaluated both by EST at the moment of catheter placement and several times during CEA, and by epidurography as reference diagnostic test. CEA and CSPA were administered for 24 or 48 h. Study parameters included pain scores assessed with a visual analogue scale, requirements of rescue pain medication, vital signs, and side-effects. Adrenaline (I and II) had no beneficial influence as regards the efficacy or tolerability of CEA. The total amounts of epidurally-infused drugs were even increased in the adrenaline group in Study II (p=0.02, RM ANOVA). Clonidine (III) augmented pain relief with lowered amounts of epidurally infused drugs (p=0.01, RM ANOVA) and reduced need for rescue oxycodone given i.m. (p=0.027, MW-U; median difference 3 mg (95% CI 0 7 mg)). Clonidine did not contribute to sedation and its influence on haemodynamics was minimal. CSPA (IV) provided satisfactory pain relief with only limited blockade of the legs (no inter-group differences). EST (V) was often related to technical problems and difficulties of interpretation, e.g., it failed to identify the four patients whose catheters were outside the spinal canal already at the time of catheter placement. As adjuvants to lumbar CEA, clonidine only slightly improved pain relief, while adrenaline did not provide any benefit. The role of EST applied at the time of epidural catheter placement or repeatedly during CEA remains open. The microcatheter CSPA technique appeared effective and reliable, but needs to be compared to routine CEA after peripheral arterial bypass surgery.
  • Heiskanen, Ilkka (Helsingin yliopisto, 2000)
  • Holmberg, Ville (Helsingin yliopisto, 2004)
  • Siira, Lotta (Helsingin yliopisto, 2014)
    Streptococcus pneumoniae, or the pneumococcus, is a bacterium of the human nasopharyngeal normal flora that also causes non-invasive respiratory tract infections, and serious infections, such as pneumonia, septicaemia, and meningitis. Globally, the rise in pneumococcal antimicrobial resistance over the past few decades is a worrying trend. The bacterium is covered by a polysaccharide capsule and over 90 different kinds of pneumococcal capsules can be recognised by serotyping. The most important serotypes are included in the available polysaccharide and conjugate vaccines. The 10-valent conjugate vaccine has been part of the Finnish national vaccination programme since September 2010. In this study, the serotype and genotype clonality of the invasive pneumococcal population in Finland was studied in relation to antimicrobial resistance. All invasive pneumococci (n=7,765) isolated in Finland during 2002-2011 and a subset of non-invasive multidrug-resistant isolates (n=12) from 2008 were serotyped and studied for antimicrobial susceptibility. The penicillin-resistant isolates were genotyped by multi locus sequence typing (MLST) and pilus-encoding virulence genes were detected by PCR. A sequential multiplex PCR assay for deducting the serotypes of pneumococci was set up tailored to the serotype distribution of invasive isolates recovered in Finland. Serotype 14 was the predominant serotype every year of the study, representing 17.5% of all the invasive isolates. The proportion of invasive isolates non-susceptible to penicillin or erythromycin was high, and it increased over the study period, reaching 22% and 26% for penicillin and erythromycin, respectively, in 2011. The proportion of non-susceptible isolates was particularly high among isolates from children and within serotype 14. Among the genotyped isolates, international resistant clones such as PMEN3 Spain9VST156 and PMEN14 Taiwan19FST236 dominated. However, novel genotypes were also found, which illustrates the continuous recombination of pneumococci. This study showed that in Finland multidrug-resistant serotype 19A pneumococci appeared among the non-invasive isolates prior to large-scale vaccination. In many countries, the clone has emerged following vaccination. Pilus-encoding gene carriage, which may serve as a competitive advantage for the bacterium by facilitating adherence to the epithelium, was frequent among the penicillin- and multidrug-resistant isolates. In the future, a vaccine targeting the pilus proteins might successfully help to control these clones. The serotyping scheme, which was set up, is useful in surveillance, as knowledge of the serotype distribution of the invasive pneumococci is essential for vaccine development and monitoring of the vaccination programme.
  • Hannula, Johanna (Helsingin yliopisto, 2000)
  • Mattila, Eero (Helsingin yliopisto, 2013)
    Background and aims. Standard treatment of recurrent Clostridium difficileinfection (CDI) with antibiotics leads to recurrences in up to 50% of patients.In recent years the incidence and mortality of Clostridium difficile (C.difficile)enteritis have increased. Nevertheless, C.difficile has rarely been isolated in extraintestinal infections. The aims of the study were to investigate efficacy of rifaximin, metronidazole, fecal microbiota transplantation (FMT) and Clostridium difficile immune whey (CDIW) in the treatment of recurrent CDI and to characterize clinical feature and risk factors for extra-intestinal CDI. Subjects and methods. Study I was a prospective, randomized, double-blind study designed to compare CDIW with metronidazole for treatment of laboratory confirmed,mild to moderate episodes of recurrent CDI. CDIW was manufactured by immunization of cows in their gestation period with inactivated C. difficile vaccine.The resulting colostrum was processed, immunoglubulins were concentrated and the end product containing high titres of C. difficile immunoglobulin was used as CDIW. 20 patients received metronidazole at a dosage of 400 mg t.i.d. and 18 patients CDIW 200 ml t.i.d. Study II was a retrospective review of 70 patients with recurrent CDI who had undergone fecal transplantation. FMT was performed at colonoscopy by infusing fresh donor feces into cecum. Before transplantation, the patients had whole-bowel lavage with polyethylene glycol solution. Study III was a retrospective study of 32 patients who were treated with rifaximin for recurrent CDI. In Study IV extra-intestinal CDIs were searched for in an electronic database of all C. difficile positive isolates found during a 10-year period. The medical records were reviewed retrospectively. Disease severity and co-morbidities of the patients were evaluated using Horn disease severity and Charlson co-morbidity indexes. Results. In Study I, 10 weeks after the beginning of treatment, sustained responses were observed in 11 (55%) of 20 patients receiving metronidazole and 10(56%) of 18 patients treated with CDIW. In Study II, 12 weeks after FMT, 66 (94%)of 70 patients had a favourable response. In Study III, 12 weeks after rifaximin treatment 17 (53%) of 30 patients had no relapse. In Study IV extra-intestinal CDI was found in 31 patients who comprised 0.17% of all CDIs. One-year mortalityrate was 36% and it correlated with the severity of underlying diseases Conclusions. CDIW was as effective as metronidazole in the prevention of CDI recurrences and it was well tolerated. FMT through colonoscopy seems to be an effective treatment also for recurrent CDI caused by the virulent C difficile 027 strain. The MIC value of rifampin seemed to predict the response to rifaximin treatment. Extra-intestinal CDIs occur mainly in hospitalized patients with significant comorbidities.Extra-intestinal CDIs in the abdominal area may result either from intestinal perforation after infection or after intestinal surgery. C. difficile may reach distant sites via bacteremia. Mortality in extra-intestinal CDIs is associated with the severity of underlying diseases
  • Liebkind, Ron (Helsingfors universitet, 2008)
    The regeneration capacity of the adult mammalian central nervous system (CNS) is limited. Following an insult to the CNS, many environmental factors inhibiting or stimulating neuronal regrowth are activated. Several molecules including laminin have stimulating effects on CNS regeneration. Laminins are essential molecular constituents of all basement membranes of the body. In the CNS, laminins are involved in developmental events, such as neuronal migration and axon guidance, while in the adult CNS they participate in the formation and maintenance of the blood-brain-barrier (BBB) and are involved in trauma reactions of the CNS. Laminin-1 is a large glycoprotein and is composed from three disulfide-bonded subunits, α1, β1, and the γ1 chain. Many neurons express γ1 laminin in the mammalian adult brain; it is critical for hippocampal neuronal survival and is expressed by glial cells after CNS injury. The KDI peptide is derived from γ1 laminin as a neurotrophic peptide. In this thesis study, we analyzed the role of γ1 laminin and its KDI peptide in different settings of CNS injury. An experimental cell culture model mimicking a damaged CNS environment showed that the KDI peptide has a stimulating effect on neuronal survival and neurite outgrowth. We analyzed neurons from human embryonic spinal cord, retina, and neocortex, leading to findings that both neuronal survival and neurite outgrowth were stimulated by the soluble KDI peptide in all of these tissues. A stereotaxic injection of kainic acid into rat hippocampus was done for testing the possible protective effect of the KDI peptide. A preceding injection of the KDI peptide protected both hippocampal and neocortical areas of excitotoxic brain damage caused by kainic acid. Kainic acid alone caused serious tissue damage to the hippocampal and neocortical injection sites. The KDI peptide showed inhibition of glutamate excitotoxicity by inhibiting kainate, AMPA, and NMDA subclasses of glutamate receptors in patch clamp recordings. Neurons were cultured from human embryonic neocortex and from HEK 293 cells expressing recombinant glutamate subunits. These studies indicate that the KDI peptide of γ1 laminin enhances neuronal survival and protects against glutamate excitotoxicity at least partially through inhibition of various glutamate receptors. Following middle cerebral artery occlusion leading to focal brain ischemia in rats, various laminins were mapped both spatially and temporally. Laminin-1 was increased in basement membranes and scar-forming extracellular matrix; γ1 laminin was in-duced earlier than other laminins and expressed by reactive astrocytes. Similarly, the KDI peptide of γ1 laminin was expressed by reactive astrocytes surrounding the ischemic region but detected along major neuronal pathways as well. The different patterns of laminin expression suggest involvement of different laminins in different functions in the pathophysiology of experimental brain ischemia. In general, these studies present novel data on the expression of laminins in the healthy and damaged brain, demonstrate protective effects of the KDI tripeptide of γ1 laminin in cell cultures and in vivo in the brain, and give clues as to the mechanisms of KDI peptide neuroprotection.
  • Palojärvi, Anniina (Helsingin yliopisto, 2014)
    A complex interaction prevails between coagulation and inflammation. The coagulation system is adapted to thrombotic challenges during and after birth, leading to specific features in the coagulation system of the newborn. Inflammation and intra-alveolar fibrin formation characterize respiratory distress syndrome (RDS). Tissue factor (TF) is a link between inflammation and coagulation pathways. In the very low birth weight (VLBW) infant, birth and intensive care present major immunological challenges, and the developmental immaturity of the immune system adds to the risks of intensive care. A protective response to a strong inflammatory stimulus downregulates the antigen-presenting molecules (Human leukocyte antigen (HLA)-DR) on monocytes. If severe, however, the response may lead to immunodepression or immunoparalysis, which in adults is associated with increased morbidity and death. Antenatal betamethasone treatment for mothers at risk for premature delivery effectively reduces neonatal morbidity and mortality. This thesis evaluates the bidirectional interaction between inflammation and coagulation and combines the findings in VLBW infants with clinical morbidity. Patients were 56 VLBW infants, with a gestational age (GA) of less than 32 weeks and a birth weight of less than 1500 g. A control population comprised 25 healthy infants with a GA of more than 34 weeks. VLBW infants showed low monocyte HLA-DR expression. On day 3, 45% of infants presented with immunodepression. VLBW infants showed high plasma TF in circulation, but which did not lead to coagulation. In VLBW infants, tissue factor pathway inhibitor (TFPI) was the main anticoagulant in the first days; on day 3, however, the TF surge exceeded the TFPI capacity, leaving the VLBW infant with a pool of plasma TF. In VLBW infants, antenatal betamethasone associated with immunodepression and suppressed both proinflammatory IL-6 and anti-inflammatory IL-10. VLBW infants are postnatally in a state of immunodepression, which associated with RDS, low GA, and subsequent infections. Immunodepression may represent a link between low GA and risk for infections. TF is expressed in the lungs of a VLBW infant and leaks into circulation. TFPI could not control the TF surge on day 3. Plasma TF does not lead to thrombin formation, thereby making it available for inflammatory pathways (e.g. protease-activated receptors (PARs)). VLBW infants showed an inflammatory profile similar to adult sepsis or acute respiratory distress syndrome, with additional VLBW-specific features: a lower net anti-inflammatory cytokine effect without TF-induced activation of coagulation. Antenatal betamethasone (BM) was associated in a time-dependent manner to immunodepression, those infants with BM less than 24 hours before birth showing the deepest nadir in HLA-DR expression.
  • Pietola, Laura (Helsingin yliopisto, 2012)
    Hearing loss is the most common sensory deficit in humans. Genetic defects play a major part among patients with sensorineural hearing loss. Usher syndrome (USH) is an autosomal recessive disorder defined by bilateral sensorineural hearing loss and a visual impairment phenotypically similar to retinitis pigmentosa (RP). USH is divided into three main clinical types (USH1, USH2 and USH3), based on the severity and progression of the hearing impairment, the presence or absence of vestibular dysfunction, and the age of onset of RP. The most common form of Usher syndrome in Finland is USH3, which comprises 40% of all USH cases. USH3 is caused by mutations in the clarin 1 (CLRN1) gene. To date, treatment methods for sensorineural hearing loss are limited to rehabilitation with traditional hearing aids or cochlear implantation. An ideal cure would be targeted, long-term or permanent, and should cause as little damage as possible to the inner ear structure. Our studies focused on cochlear gene therapy and Usher syndrome type 3 (USH3). Finnish USH3 patients answered three questionnaires which evaluated their quality of life after cochlear implantation. We also collected data of these patients audiological tests and speech discrimination tests from their patient records. We developed an in vitro model suitable for cochlear gene transfer studies from a detached mouse round window membrane (RWM) and also tested the suitability of adeno-associated virus vectors and lentivirus vectors for cochlear gene therapy applications in cell lines and in the mouse cochlea. Cochlear implantation is beneficial for USH3 patients and improves their quality of life. The detached mouse RWM model is suitable for inner ear gene transfer studies in vitro. Manipulation of the RWM with AgNO3, trichloracetic acid or histamine-glycerol did not increase the permeability of the membrane. Lentivirus vectors are safe and can be used in gene transfer into the perilymph. Silencing of p53 protein may decrease apoptosis in the kanamycin-damaged mouse cochlea. AAV-delivered clarin-1 ribozyme may induce apoptosis in cochlear hair cells and cells of the stria vascularis. Apoptosis could explain the progressive nature of USH3.
  • Bidel, Siamak (Helsingin yliopisto, 2008)
    Type 2 diabetes is one of the diseases that largely determined by lifestyle factors. Coffee is one of the most consumed beverages in the world and recently released data suggest the effects of coffee consumption on type 2 diabetes. The objective of the present study was to evaluate the effects of habitual coffee consumption on various aspects of type 2 diabetes and its most common complications. This study is part of the national FINRISK studies. Baseline surveys were carried out between 1972 and 1997. The surveys covered two eastern regions in 1972 and 1977, but were expanded to include a third region in southwestern Finland in 1982, 1987, 1992, and 1997. The Helsinki capital area was included in the survey in 1992 and 1997 and the Oulu province, in northern Finland, in 1997. Each survey was drawn from an independent random sample of the national register of subjects aged 25-64. In 1997, an additional sample of subjects aged 65-74 was conducted. The blood pressure, weight, and height of subjects were measured. By using self-administered questionnaires data were collected on medical history, socioeconomic factors, physical activity, smoking habits, and alcohol, coffee, and tea consumption. Higher coffee consumption was associated with higher body mass index, occupational physical activity and cigarette smoking, and lower blood pressure, education level, leisure time physical activity, tea consumption and alcohol use. Age, body mass index, systolic blood pressure and current smoking were positively associated with the risk of type 2 diabetes, however, education, and occupational, commuting and leisure time physical activity were inversely associated. The significant inverse association between coffee consumption and the risk of type 2 diabetes was found in both sexes but the association was stronger in women. Coffee consumption was significantly and inversely associated with fasting glucose, 2-hour plasma glucose, fasting insulin, impaired fasting glucose, impaired glucose regulation, and hyperinsulinemia among both men and women and with isolated impaired glucose tolerance among women. Serum gamma-glutamyltransferase modified the association between coffee consumption and incident diabetes. Among subjects with high serum -glutamyltransferase (>75th percentile), coffee consumption showed an inverse association for women, as well as men and women combined. An inverse association also occurred between coffee consumption and the risk of total, cardiovascular disease, and coronary heart disease mortality among patients with type 2 diabetes. The results of this study showed that habitual coffee consumption may be associated with a reduced risk of type 2 diabetes. Coffee consumption may have some effects on several markers of glycemia, and may lower the incident of type 2 diabetes in high normal serum -glutamyltransferase levels. Total, cardiovascular disease, and coronary heart disease mortality rate among subjects with type 2 diabetes may also be reduced by coffee consumption.
  • Rapeli, Pekka (National Institute for Health and Welfare (THL), Finland, 2014)
    Opioid substitution treatment with buprenorphine or methadone is the most effective treatment for opioid-dependence. In this study attention, working memory, and episodic memory functioning in opioid-substituted patients was examined cross-sectionally and longitudinally. Methadone patients performed worse in many attention-related reaction time tasks in relation to controls or buprenorphine patients. In each drug group, drug treatment variables predicted 10% of the attention performance. In most working memory tests both drug groups performed worse than controls. A group by time interaction in one working memory test in buprenorphine patients may indicate improvement of function. Use of benzodiazepine medication predicted impaired working memory performance. In verbal episodic memory tests treatment with more than one other psychoactive drug (than opioid or benzodiazepine) and frequent substance abuse in the past month predicted 20% of performance. Almost normal cognitive performance in stable opioid substitution treatment supports the idea of efficient compensation of the opioid abuse history related neural burden. The results are relevant for patients and prescribers when choosing treatment options or rehabilitation goals.
  • Kivitie-Kallio, Satu (Helsingin yliopisto, 2000)
  • Sevastianova, Ksenia (Helsingin yliopisto, 2011)
    Introduction: Combination antiretroviral therapy (cART) has decreased morbidity and mortality of individuals infected with human immunodeficiency virus type 1 (HIV-1). Its use, however, is associated with adverse effects which increase the patients risk of conditions such as diabetes and coronary heart disease. Perhaps the most stigmatizing side effect is lipodystrophy, i.e., the loss of subcutaneous adipose tissue (SAT) in the face, limbs and trunk while fat accumulates intra-abdominally and dorsocervically. The pathogenesis of cART-associated lipodystrophy is obscure. Nucleoside reverse transcriptase inhibitors (NRTI) have been implicated to cause lipoatrophy via mitochondrial toxicity. There is no known effective treatment for cART-associated lipodystrophy during unchanged antiretroviral regimen in humans, but in vitro data have shown uridine to abrogate NRTI-induced toxicity in adipocytes. Aims: To investigate whether i) cART or lipodystrophy associated with its use affect arterial stiffness; ii) lipoatrophic SAT is inflamed compared to non-lipoatrophic SAT; iii) abdominal SAT from patients with compared to those without cART-associated lipoatrophy differs with respect to mitochondrial DNA (mtDNA) content, adipose tissue inflammation and gene expression, and if NRTIs stavudine and zidovudine are associated with different degree of changes; iv) lipoatrophic abdominal SAT differs from preserved dorsocervical SAT with respect to mtDNA content, adipose tissue inflammation and gene expression in patients with cART-associated lipodystrophy and v) whether uridine can revert lipoatrophy and the associated metabolic disturbances in patients on stavudine or zidovudine based cART. Subjects and methods: 64 cART-treated patients with (n=45) and without lipodystrophy/-atrophy (n=19) were compared cross-sectionally. A marker of arterial stiffness, heart rate corrected augmentation index (AgIHR), was measured by pulse wave analysis. Body composition was measured by magnetic resonance imaging and dual-energy X-ray absorptiometry, and liver fat content by proton magnetic resonance spectroscopy. Gene expression and mtDNA content in SAT were assessed by real-time polymerase chain reaction and microarray. Adipose tissue composition and inflammation were assessed by histology and immunohistochemistry. Dorsocervical and abdominal SAT were studied. The efficacy and safety of uridine for the treatment of cART-associated lipoatrophy were evaluated in a randomized, double-blind, placebo-controlled 3-month trial in 20 lipoatrophic cART-treated patients. Results: Duration of antiretroviral treatment and cumulative exposure to NRTIs and protease inhibitors, but not the presence of cART-associated lipodystrophy, predicted AgIHR independent of age and blood pressure. Gene expression of inflammatory markers was increased in SAT of lipodystrophic as compared to non-lipodystrophic patients. Expression of genes involved in adipogenesis, triglyceride synthesis and glucose disposal was lower and of those involved in mitochondrial biogenesis, apoptosis and oxidative stress higher in SAT of patients with than without cART-associated lipoatrophy. Most changes were more pronounced in stavudine-treated than in zidovudine-treated individuals. Lipoatrophic SAT had lower mtDNA than SAT of non-lipoatrophic patients. Expression of inflammatory genes was lower in dorsocervical than in abdominal SAT. Neither depot had characteristics of brown adipose tissue. Despite being spared from lipoatrophy, dorsocervical SAT of lipodystrophic patients had lower mtDNA than the phenotypically similar corresponding depot of non-lipodystrophic patients. The greatest difference in gene expression between dorsocervical and abdominal SAT, irrespective of lipodystrophy status, was in expression of homeobox genes that regulate transcription and regionalization of organs during embryonal development. Uridine increased limb fat and its proportion of total fat, but had no effect on liver fat content and markers of insulin resistance. Conclusions: Long-term cART is associated with increased arterial stiffness and, thus, with higher cardiovascular risk. Lipoatrophic abdominal SAT is characterized by inflammation, apoptosis and mtDNA depletion. As mtDNA is depleted even in non-lipoatrophic dorsocervical SAT, lipoatrophy is unlikely to be caused directly by mtDNA depletion. Preserved dorsocervical SAT of patients with cART-associated lipodystrophy is less inflamed than their lipoatrophic abdominal SAT, and does not resemble brown adipose tissue. The greatest difference in gene expression between dorsocervical and abdominal SAT is in expression of transcriptional regulators, homeobox genes, which might explain the differential susceptibility of these adipose tissue depots to cART-induced toxicity. Uridine is able to increase peripheral SAT in lipoatrophic patients during unchanged cART.
  • Liikanen, Ilkka (Helsingin yliopisto, 2015)
    Cancer remains a major cause of death and novel treatment modalities are needed. Oncolytic immunotherapy is a safe and promising approach, where cancer-selective viruses kill only cancer cells and mount an immune response against the tumor. We aimed to improve oncolytic adenoviral immunotherapy by combining it with chemotherapy and radiotherapy, and by identifying resistance mechanisms and biomarkers. We first showed that combining radiotherapy with adenoviral vector proteins E4orf3 and E4orf6, but not E1B55K, enhanced DNA damage accumulation and cancer cell killing, and inhibited prostate tumor growth in mice. This intrinsic ability of adenoviruses to radiosensitize cells could be harnessed against cancer cells by selective targeting, thus increasing efficacy while reducing the harmful side-effects of radiotherapy. In study two, we established two ovarian cancer mouse models, where tumors relapse despite the presence of functional oncolytic adenovirus, with tumor stroma maintaining the virus resistance. We identified upregulated interferon signaling in the resistant tumors by microarray, while pathway analyses suggested potential therapeutic targets, and myxovirus resistance protein A (MxA) was found a protein level indicator correlating with resistance to virus. Our results provide a putative biomarker and targets, which can help in detecting and overcoming resistance against oncolytic adenovirus. Antitumor T-cell activation appears to require autophagy and immunogenic cell death (ICD). In a translational study, we demonstrated preclinically that oncolytic adenovirus together with low-dose temozolomide and cyclophosphamide increased ICD and autophagy, resulting in tumor growth inhibition. Combination therapy was found safe in 41 treatments given to patients with refractory solid tumors in the context of an advanced therapy access program (ATAP). Increase of an ICD marker protein high-mobility group box 1 (HMGB1) and antitumor T-cell activity suggested activation of immune responses. Disease stabilization or better was observed in 67% of evaluable treatments, and as an estimated effect on survival, combination-treated patients trended for increased overall survival over non-randomized control patients. Biomarkers are urgently needed for identification of cancer patients likely to benefit from immunotherapy. Because HMGB1 protein is emerging a key player in immunomodulation, we addressed the biomarker value of HMGB1 serum level in an ATAP cohort of 202 cancer patients treated with oncolytic adenoviruses: Patients with low-baseline HMGB1 showed significantly improved overall survival and disease control rate in multivariate analyses as compared to high-baseline patients. Both patient groups showed good safety. HMGB1-low patients seemed to benefit from immunogenic virus constructs and antitumor T-cell activity. Thus, we have identified HMGB1 as a novel prognostic and predictive biomarker for oncolytic immunotherapy, which may distinguish between immunologically inert and responsive cancer patients. This thesis provides rationale for combining oncolytic adenoviruses with radiotherapy, low-dose temozolomide and cyclophosphamide. We report safety, possible signs of efficacy, and immunological effects in altogether 238 patient treatments, and introduce promising biomarkers for oncolytic immunotherapy. Our results can help in designing clinical trials and developing oncolytic adenovirus treatments.
  • Hannila-Handelberg, Tuula (Helsingin yliopisto, 2009)
    Most of the diseases affecting public health, like hypertension, are multifactorial by etiology. Hypertension is influenced by genetic, life style and environmental factors. Estimation of the influence of genes to the risk of essential hypertension varies from 30 to 50%. It is plausible that in most of the cases susceptibility to hypertension is determined by the action of more than one gene. Although the exact molecular mechanism underlying essential hypertension remains obscure, several monogenic forms of hypertension have been identified. Since common genetic variations may predict, not only to susceptibility to hypertension, but also response to antihypertensive drug therapy, pharmacogenetic approaches may provide useful markers in finding relations between candidate genes and phenotypes of hypertension. The aim of this study was to identify genetic mutations and polymorphisms contributing to human hypertension, and examine their relationships to intermediate phenotypes of hypertension, such as blood pressure (BP) responses to antihypertensive drugs or biochemical laboratory values. Two groups of patients were investigated in the present study. The first group was collected from the database of patients investigated in the Hypertension Outpatient Ward, Helsinki University Central Hospital, and consisted of 399 subjects considered to have essential hypertension. Frequncies of the mutant or variant alleles were compared with those in two reference groups, healthy blood donors (n = 301) and normotensive males (n = 175). The second group of subjects with hypertension was collected prospectively. The study subjects (n=313) underwent a protocol lasting eight months, including four one-month drug treatment periods with antihypertensive medications (thiazide diuretic, β-blocker, calcium channel antagonist, and an angiotensin II receptor antagonist). BP responses and laboratory values were related to polymorphims of several candidate genes of the renin-angiotensin system (RAS). In addition, two patients with typical features of Liddle’s syndrome were screened for mutations in kidney epithelial sodium channel (ENaC) subunits. Two novel mutations causing Liddle’s syndrome were identified. The first mutation identified located in the beta-subunit of ENaC and the second mutation found located in the gamma-subunit, constituting the first identified Liddle mutation locating in the extracellular domain. This mutation showed 2-fold increase in channel activity in vitro. Three gene variants, of which two are novel, were identified in ENaC subunits. The prevalence of the variants was three times higher in hypertensive patients (9%) than in reference groups (3%). The variant carriers had increased daily urinary potassium excretion rate in relation to their renin levels compared with controls suggesting increased ENaC activity, although in vitro they did not show increased channel activity. Of the common polymorphisms of the RAS studied, angiotensin II receptor type I (AGTR1) 1166 A/C polymorphism was associated with modest changes in RAS activity. Thus, patients homozygous for the C allele tended to have increased aldosterone and decreased renin levels. In vitro functional studies using transfected HEK293 cells provided additional evidence that the AGTR1 1166 C allele may be associated with increased expression of the AGTR1. Common polymorphisms of the alpha-adducin and the RAS genes did not significantly predict BP responses to one-month monotherapies with hydroclorothiazide, bisoprolol, amlodipin, or losartan. In conclusion, two novel mutations of ENaC subunits causing Liddle’s syndrome were identified. In addition, three common ENaC polymorphisms were shown to be associated with occurrence of essential hypertension, but their exact functional and clinical consequences remain to be explored. The AGTR1 1166 C allele may modify the endocrine phenotype of hypertensive patients, when present in homozygous form. Certain widely studied polymorphisms of the ACE, angiotensinogen, AGTR1 and alpha-adducin genes did not significantly affect responses to a thiazide, β-blocker, calcium channel antagonist, and angiotensin II receptor antagonist.
  • Korvenoja, Antti (Helsingin yliopisto, 2007)
    MEG directly measures the neuronal events and has greater temporal resolution than fMRI, which has limited temporal resolution mainly due to the larger timescale of the hemodynamic response. On the other hand fMRI has advantages in spatial resolution, while the localization results with MEG can be ambiguous due to the non-uniqueness of the electromagnetic inverse problem. Thus, these methods could provide complementary information and could be used to create both spatially and temporally accurate models of brain function. We investigated the degree of overlap, revealed by the two imaging methods, in areas involved in sensory or motor processing in healthy subjects and neurosurgical patients. Furthermore, we used the spatial information from fMRI to construct a spatiotemporal model of the MEG data in order to investigate the sensorimotor system and to create a spatiotemporal model of its function. We compared the localization results from the MEG and fMRI with invasive electrophysiological cortical mapping. We used a recently introduced method, contextual clustering, for hypothesis testing of fMRI data and assessed the the effect of neighbourhood information use on the reproducibility of fMRI results. Using MEG, we identified the ipsilateral primary sensorimotor cortex (SMI) as a novel source area contributing to the somatosensory evoked fields (SEF) to median nerve stimulation. Using combined MEG and fMRI measurements we found that two separate areas in the lateral fissure may be the generators for the SEF responses from the secondary somatosensory cortex region. The two imaging methods indicated activation in corresponding locations. By using complementary information from MEG and fMRI we established a spatiotemporal model of somatosensory cortical processing. This spatiotemporal model of cerebral activity was in good agreement with results from several studies using invasive electrophysiological measurements and with anatomical studies in monkey and man concerning the connections between somatosensory areas. In neurosurgical patients, the MEG dipole model turned out to be more reliable than fMRI in the identification of the central sulcus. This was due to prominent activation in non-primary areas in fMRI, which in some cases led to erroneous or ambiguous localization of the central sulcus.
  • Rautemaa, Riina (Helsingin yliopisto, 2001)