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  • Oksjoki, Riina (Helsingin yliopisto, 2006)
    Atherosclerosis is an inflammatory disease characterized by accumulation of lipids in the inner layer of the arterial wall. During atherogenesis, various structures that are recognized as non-self by the immune system, such as modified lipoproteins, are deposited in the arterial wall. Accordingly, atherosclerotic lesions and blood of humans and animals with atherosclerotic lesions show signs of activation of both innate and adaptive immune responses. Although immune attack is initially a self-protective reaction, which is meant to destroy or remove harmful agents, a chronic inflammatory state in the arterial wall accelerates atherosclerosis. Indeed, various modulations of the immune system of atherosclerosis-prone animals have provided us with convincing evidence that immunological mechanisms play an important role in the pathogenesis of atherosclerosis. This thesis focuses on the role of complement system, a player of the innate immunity, in atherosclerosis. Complement activation via any of the three different pathways (classical, alternative, lectin) proceeds as a self-amplifying cascade, which leads to the generation of opsonins, anaphylatoxins C3a and C5a, and terminal membrane-attack complex (MAC, C5b-9), all of which regulate the inflammatory response and act in concert to destroy their target structures. To prevent uncontrolled complement activation or its attack against normal host cells, complement needs to be under strict control by regulatory proteins. The complement system has been shown to be activated in atherosclerotic lesions, modified lipoproteins and immune complexes containing oxLDL, for instance, being its activators. First, we investigated the presence and role of complement regulators in human atherosclerotic lesions. We found that inhibitors of the classical and alternative pathways, C4b-binding protein and factor H, respectively, were present in atherosclerotic lesions, where they localized in the superficial proteoglycan-rich layer. In addition, both inhibitors were found to bind to arterial proteoglycans in vitro. Immunohistochemical stainings revealed that, in the superficial layer of the intima, complement activation had been limited to the C3 level, whereas in the deeper intimal layers, complement activation had proceeded to the terminal C5b-9 level. We were also able to show that arterial proteoglycans inhibit complement activation in vitro. These findings suggested to us that the proteoglycan-rich layer of the arterial intima contains matrix-bound complement inhibitors and forms a protective zone, in which complement activation is restricted to the C3 level. Thus, complement activation is regulated in atherosclerotic lesions, and the extracellular matrix is involved in this process. Next, we studied whether the receptors for the two complement derived effectors, anaphylatoxins C3a and C5a, are expressed in human coronary atherosclerotic lesions. Our results of immunohistochemistry and RT-PCR analysis showed that, in contrast to normal intima, C3aR and C5aR were highly expressed in atherosclerotic lesions. In atherosclerotic plaques, the principal cells expressing both C3aR and C5aR were macrophages. Moreover, T cells expressed C5aR, and a small fraction of them also expressed C3aR, mast cells expressed C5aR, whereas endothelial cells and subendothelial smooth muscle cells expressed both C3aR and C5aR. These results suggested that intimal cells can respond to and become activated by complement-derived anaphylatoxins. Finally, we wanted to learn, whether oxLDL-IgG immune complexes, activators of the classical complement pathway, could have direct cellular effects in atherogenesis. Thus, we tested whether oxLDL-IgG immune complexes affect the survival of human monocytes, the precursors of macrophages, which are the most abundant inflammatory cell type in atherosclerotic lesions. We found that OxLDL-IgG immune complexes, in addition to transforming monocytes into foam cells, promoted their survival by decreasing their spontaneous apoptosis. This effect was mediated by cross-linking Fc receptors with ensuing activation of Akt-dependent survival signaling. Our finding revealed a novel mechanism by which oxLDL-IgG immune complexes can directly affect the accumulation of monocyte-macrophages in human atherosclerotic lesions and thus play a role in atherogenesis.
  • Kumar, Arun (Helsingin yliopisto, 2014)
    Many unknown species of human DNA viruses have recently (2005-2013) been discovered by using modern molecular and bioinformatic tools. The clinical and pathogenic roles of these viruses are presently known only fragmentarily; however they were found in symptomatic patients, and some have been shown to cause severe infectious illness, or cancer. Some of these emerging DNA viruses are examined in this thesis: Human Bocavirus 1 (HBoV1), Merkel cell polyomavirus (MCV or MCPyV) and Trichodysplasia spinulosa-associated polyomavirus (TSV or TSPyV). Viruses like these are of fundamental importance in the genesis of not only of acute but also of chronic or late-onset illness. The immunobiology and pathogenesis of these new viruses along with the already known DNA virus (parvovirus B19 or B19) can be found by the immunological and molecular methods. For years it was thought that parvovirus B19, was the sole human-pathogen among its family members. In 2005 a new pathogenic species, HBoV1 (previously denoted HBoV), was discovered by random-PCR from a nasopharyngeal aspirate. The existing data strongly suggest that HBoV1 causes a respiratory illness in young children. The aim of our study was to increase our knowledge on HBoV1-specific Th-cell immunity by examining T-cell proliferation and cytokine responses in asymptomatic adults. HBoV1-specific response was compared to those elicited by B19. B19-specific Th-cell immunity appears to be more divergent (in terms of cytokine response patterns) than the HBoV1-specific one. The present study also suggests that interleukin-13 (IL-13) response induced by HBoV1 may contribute to the airway pathology like asthma or bronchiolitis. A novel concept of CD4+ T-cells with cytolytic potential (CD4+ CTL) is emerging. Very recently, CD4+ CTL have been implicated in the control of persistent viral infections, e.g., Epistein-Barr virus (EBV), hepatitis C virus (HCV) and HIV-1. While human parvovirus B19 can establish persistence, yet no data exist on the presence of B19-specific CD4+ CTLs. Detection of vigorous B19-specific granzyme B (GrB) and perforin responses in seropositive individuals points to a role of CD4+ CTL also in B19 immunity. Such cells could function within immune regulation and in the triggering of autoimmune phenomena such as Systemic Lupus Erythematosus (SLE) or rheumatoid arthritis (RA). The newly discovered MCV resides in approximately 80% of Merkel cell carcinomas (MCC). The integration of MCV genome in-to the genome of host cell has been suggested to be the primary reason for this rare and aggressive skin cancer. Here we studied the T-cell immunity against this carcinogenic virus. We found that interferon-γ (IFN-γ) is the dominant cytokine among MCV-seropositive individuals and suggest that IFN-γ plays an important role in surveillance against MCV-induced disease. Our studies also suggested a role for IL-13 and IL-10 in anti-tumor immunity and immune regulation, respectively. TSV, while exhibiting high seroprevalence in general population, has been detected in trichodysplasia spinulosa (TS) skin lesions, suggesting an etiological role in this disease. In order to characterize Th-cell immunity against TSV, and to permit its comparisons with MCV-specific Th-cell immunity, we studied TSV and MCV-specific proliferation and cytokine responses in healthy volunteers and in one MCC patient. While an association between humoral and cellular responses was detectable with MCV, it was found to be weaker than the humoral and cellular responses detectable with TSV. Despite the significant homology in amino acid sequences of VP1, Th-cell crossreactivity was not evident between these viruses. As CD8+ T-cells specific for MCV LT-Ag oncoprotein clearly provide an important defence mechanism against MCC, the MCV VP1-specific Th-cells may also be important in preventing the oncogenic process, by suppressing MCV replication with antiviral cytokines such as IFN-γ. Parvoviruses (HBoV1 and B19) and polyomaviruses (MCV and TSV) induce effector CD4+ T-cell responses that are best known for their ability to protect against viral infections. Besides helper functions, CD4+ T-cell contribute to viral control and elimination by CD4-mediated cytotoxic effector functions. Thus, understanding of the CD4+ T-cell immunity is of key importance in the development of vaccines and therapeutic agents against life threatening infectious pathogens.
  • Suvilehto, Jari (Helsingin yliopisto, 2009)
    In the first part of this thesis the association of different forms of sinonasal diseases and plasma concentrations of C3, C4, immunoglobulins, immunoglobulin G subclasses, C4A and C4B gene numbers were studied in 287 adult patients and 150 sex-matched adult controls. Patients were well characterized and stratified into groups using strict clinical criteria and females and males were also studied as separate groups. Severe primary antibody antibody deficiencies were rare in patients coming to sinonasal operations. Female patients had more recurrent sinusitis and other mucosal infections and males had more nasal polyposis. Upregulation of complement activity was seen in acute rhinosinusitis patients (high levels of plasma C3, C4, and complement classical pathway activity CH50) and male patients coming to sinonasal operations (high levels of plasma C3 and C4). In females, total and partial C4B deficiencies and lower levels of IgG1 and IgG3 were associated with rhinosinusitis leading to sinonasal operations. C4A deficiencies were found to predispose to severe chronic rhinosinusitis in females and males. In female patients with chronic or recurrent rhinosinusitis with nasal polyposis C4B deficiencies seem to predispose to the disease, but in males with a similar disease C4B deficiencies seem to be protective. This suggests a different pathophysiology between sexes in this form of sinonasal disease. In the second part of this thesis work 213 children coming to elective tonsillectomy were studied and compared with 155 randomly selected school children. An association with recurrent upper respiratory tract infections and hypersensitivity disorders was seen especially in children under 7 years of age. However, this association was not seen in levels of specific IgE to respiratory allergens in the same age group. Both symptomatic respiratory allergy and specific IgE to respiratory allergens became more common in boys than girls over 7 years of age. We were able to show that although both rhinoviruses and bacterial pathogens were found in the tonsils, no association between their presence and clinical forms of tonsillar disease was seen. The ability of GAS to bind complement regulators FH and C4BP did not differ between strains causing tonsillar diseases or septicemia, suggesting that other virulence mechanisms of the bacteria are more important.
  • Marschan, Emma (Helsingin yliopisto, 2007)
    Epidemiological and experimental studies suggest that changes in gut microbial balance are associated with increases in the prevalence of allergic diseases. Probiotics are proposed to provide beneficial immunoregulatory signals which aid in oral tolerance achievement and alleviation of symptoms of allergic diseases. The present study evaluates both the immunological mechanisms of probiotics in infants with allergic diseases and their preventive aspect among infants prone to allergy. Furthermore, the purpose of the study was to characterise the immunological features of cord blood mononuclear cells (CBMCs) in infants at high genetic risk for allergy. GATA-3 expression (p = 0.03), interleukin (IL) -2(p = 0.026), and IL-5 (p = 0.013) secretion of stimulated CBMCs were higher in IgE-sensitized infants at age 2 than in non-allergic, non-sensitized infants. Lactobacillus GG (LGG) treatment increased secretion of IFN-γ by PBMCs in vitro in infants with cow s milk allergy (CMA) (p = 0.006) and in infants with IgE-associated eczema (p = 0.017), when compared to levels in the placebo group. A probiotic mixture, increased secretion of IL-4 by PBMCs in vitro in infants with CMA (p = 0.028), when compared with placebo-group levels. The LGG treatment induced higher plasma C-reactive protein (CRP) (p = 0.021) and IL-6 (p = 0.036) levels in infants with IgE-associated eczema than in the placebo group. The probiotic mixture induced higher plasma IL-10 levels in infants with eczema (p = 0.016). In the prevention study of allergic dis-eases, the infants receiving the probiotic mixture had higher plasma levels of CRP (p = 0.008), total IgA (p = 0.016), total IgE (p = 0.047), and IL-10 (p = 0.002) than did infants in the placebo group. Increased CRP level at age 6 months was associated with a decreased risk for eczema at age 2 not only in the infants who received probiotics but also in the placebo group (p = 0.034). In conclusion, the priming of the GATA-3 and IL-5 pathway can occur in utero, and a primary feature of T-cells predisposing to IgE-sensitization seems to directly favour Th2 deviation. LGG treatment induced increased plasma levels of CRP and IL-6 in infants with IgE-associated eczema, suggesting an activation of innate immu-nity. The probiotic mixture, when given to allergy-prone infants, induced inflammation, detected as increased plasma CRP levels, which at age 6 months was associated with decreased risk for eczema at age 2.The probiotic-induced response in allergy prone infants was characterized by their higher plasma IL-10, total IgE, and CRP levels, without induction of an allergen-specific IgE response. In this respect, the probiotics in infancy appear to induce protective immune profiles that are characteristic for chronic low-grade inflammation, a response resembling that of helminth-like infections.
  • Österlund, Pamela (Helsingin yliopisto, 2003)
  • Nissinen, Riikka (Helsingin yliopisto, 2003)
  • Kekkonen, Riina (University of Helsinki, 2008)
    Probiotics have strain-specific effects on immune system in healthy adults Probiotics are strain-specifically able to modulate the release and actions of inflammatory mediators in healthy adults. Immunomodulatory effects of probiotic multispecies should be studied as the effects differ from single strains. MSc Riina Kekkonen investigated the immunomodulatory effects of probiotics in a primary cell culture model using human peripheral blood mononuclear cells (PBMC) as well as in healthy adults in randomized, double-blind, placebo-controlled clinical intervention studies in her thesis. Previously, probiotics have been mostly examined in the prevention and treatment of different gastrointestinal diseases and allergies. Probiotic products, however, are usually consumed by the general, healthy population but not much is known on their immunomodulatory effects in healthy adults. Probiotic strains from six different genera showed clear differences in their ability to induce cytokine responses in PBMC in vitro. Strains belonging to the Streptococcus and Leuconostoc genera were the most potent inducers of Th1-type cytokines, whereas strains from the Bifidobacterium and Propionibacterium genera induced anti-inflammatory IL-10 production. No combinations of probiotics resulted in enhanced cytokine production compared with individual strains, suggesting that different bacteria compete with each other during host cell-probiotic interactions. The selection of strains for the clinical trials was made based on their anti-inflammatory potential. The strains possessing the best anti-inflammatory potential, namely B. lactis ssp. animalis Bb12 (Bb12) and P. freudenreichii ssp. shermanii JS (PJS), along with L. rhamnosus GG (LGG) as a well-documented reference probiotic, were thus selected for further clinical studies in healthy adults. The results of the in vitro setting did not entirely reflect the in vivo results as the best anti-inflammatory strain was LGG, which induced only moderate IL-10 production in vitro compared with Bb12 and PJS strains. In the three-week clinical setting in healthy adults, LGG seemed to demonstrate the best anti-inflammatory potential reflected as a small decrease in inflammatory mediators, such as sensitive CRP and inflammatory cytokines like TNF-alfa as well as in the modulation of global serum lipidomics profiles. In the three-month intervention LGG had no effect on the incidence or duration of respiratory infections in healthy adults but it was able to reduce the duration of gastrointestinal symptoms. Probiotics have strain-specific effects on immune system in healthy adults and especially L. rhamnosus GG seemed to posses anti-inflammatory potential. The in vitro screening of cytokine responses in a primary cell culture using human PBMC should not be used as the only indicator of immunomodulatory properties of probiotics, as the in vitro model did not reflect the effects in vivo. Instead, the ex vivo production of cytokines in PBMC after probiotic intervention could offer a relatively easy and quick model for screening of immunomodulatory effects of probiotics. The mechanisms of specific host-probiotic interactions in the gut resulting in systemic and clinical effects warrants further investigations.
  • Bayat, Fariborz (Helsingin yliopisto, 2010)
    The aim of the present study was to determine relationships between insurance status and utilization of oral health care and its characteristics and to identify factors related to insured patients’ selection of dental clinic or dentist. The study was based on cross-sectional data obtained through phone interviews. The target population included adults in the city of Tehran. Using a two-stage stratified random technique, 3,200 seven-digit numbers resembling real phone numbers were drawn; when calling, 1,669 numbers were unavailable (busy, no answer, fax, line blocked). Of the 1,531 subjects who answered the phone call, 224 were outside the target age (under 18), and 221 refused to respond, leaving 1,086 subjects in the final sample. The interviews were carried out using a structured questionnaire and covered characteristics of dental visits, the respondent’s reason for selecting a particular dentist or clinic and demographic and socio-economic background (gender, age, level of education, income, and insurance status). Data analysis included the Chi-square test, ANOVA, and logistic regression and the corresponding odds ratios (OR). Of all the 1,086 respondents, 57% were women, 62% were under age 35, 46% had a medium and 34% a high level of education, 13% were under the poverty line, and 70% had insurance coverage; 64% with the public, and 6% with a commercial insurance. Having insurance coverage was more likely for women (OR=1.5), for those in the oldest age group (OR=2.0), and for those with a high level of education (OR=2.5). Of those with dental insurance, 54% reported having had a dental visit within the past 12 months ; more often by those with commercial insurance in comparison with public (65% vs. 53% p<0.001). Check-up as the reason for the most recent visit occurred most frequently among those with commercial insurance (28%) compared with those having public insurance (16%) or being non-insured (13%) (p<0.001). Having had two or more dental visits within the past 12 months was most common among insured respondents, when compared with the non-insured (31% vs. 22% p=0.01). The non-insured respondents reported tooth extractions almost twice as frequently as did the insured ones (p<0.001). Of the 726 insured subjects, 60% selected fully out-of-pocket-paid services (FOP), and 53% were unaware of their insurance benefits. Of those who selected FOP, good interpersonal aspects (OR=4.6), being unaware of dental insurance benefits (OR=4.6), and good technical aspects (OR=2.3) as a reason had greater odds of selecting FOP. The present study revealed that dental insurance was positively related to demand for oral health care as well as to utilization of services, but to the latter with a minor extent. Among insured respondents, despite their opportunity to use fully or highly subsidized oral health care services, good interpersonal relationship and high quality of services were the most important factors when an insured patient selected a dentist or a clinic. The present findings indicate a clear need to modify dental insurance systems in Iran to facilitate optimal use of oral health care services to maximize the oral health of the population. A special emphasis in the insurance schemes should be focused on preventive care.
  • Halmesmäki, Karoliina Henriikka (Helsingin yliopisto, 2007)
    The `VuoKKo` trial consisted of 236 women referred and randomised due to menorrhagia in the five university hospitals of Finland between November 1994 and November 1997. Of these women, 117 were randomised to hysterectomy and 119 to use levonorgestrel-releasing intrauterine system (LNG-IUS) to treat this complaint. Their follow-up visits took place six and twelve months after the treatment and five years after the randomisation. The first aim in the primary trial was quality-of-life and monetary aspects, and secondly in the present study to compare ovarian function, bone mineral density (BMD) and sexual functioning after these two treatment options. Ovarian function seemed to decrease after hysterectomy, demonstrated by increased hot flashes and serum follicle-stimulating hormone concentrations twelve months after the operation. Such an increase was not seen among LNG-IUS users. The pulsatility index of intraovarian arteries measured by two-dimensional ultrasound decreased in the hysterectomy group, but not in the LNG-IUS group. The decrease in serum inhibin B concentrations was similar in both groups, while ovarian artery circulation remained unchanged. BMD of the women measured by dual x-ray absorptiometry (DXA) at the lumbar spine and femoral neck at baseline and at five years after treatment showed BMD decrease at the lumbar spine among hysterectomised women, but not among LNG-IUS users. In both groups, BMD at the femoral neck had decreased. Differences between the groups were not, however, significant. Sexual functioning assessed by McCoy s sexual scale showed that sexual satisfaction as well as intercourse frequency had increased and sexual problems decreased among hysterectomised women six months after treatment. Among LNG-IUS users, sexual satisfaction and sexual problems remained unchanged. Although, the two groups did not differ in terms of sexual satisfaction or sexual problems at one-year and five-year follow-ups, LNG-IUS users were less satisfied with their partners than hysterectomised women.
  • Helakorpi, Satu (Helsingin yliopisto, 2008)
    The aim of the study was to evaluate the impact of the Finnish tobacco control measures for reduction of smoking. First, the trends and patterns in ever smoking among adult Finns in 1978 2001 as well as the associations of trends with the Tobacco Control Act in 1976 were examined. Secondly, the impact of the 1976 TCA on the proportion of ever daily smokers in different socioeconomic groups was studied. Thirdly, the impact of the 1995 TCAA on recent trends in the prevalence of daily smoking was evaluated by gender and employment status. Fourthly, the trends of exposure to environmental tobacco smoke (ETS) at workplaces and homes were investigated. The study is based on data of the Health Behaviour among the Finnish Adult Population surveys. Among Finnish men smoking initiation declined from earlier to later cohorts, whereas among women it increased in successive birth cohorts born before 1956. The lasting differences between birth cohorts as regards ever daily smoking reflected well the impact of measures to reduce smoking in Finland in 1976. Smoking initiation in the birth cohorts (born in 1961 or later) which were in critical age as regards the risk of smoking initiation when the TCA came into force was less common than could be expected according to the trends seen in the earlier birth cohorts. Marked socioeconomic differences were found in smoking in the different birth cohorts. Smoking was more prevalent in the lower socioeconomic groups than in the higher ones, and the differences were larger in the later birth cohorts compared to the earlier ones. The differences between the birth cohorts in ever daily smoking were compatible with the hypothetical impact of the TCA in almost all socioeconomic groups, except farmers. Among men the 1976 TCA appears to have had the greatest impact on white-collar employees. Among women the effect of the act was highly significant in all socioeconomic groups. However, female smoking prevalence continues to show wide socioeconomic disparities. Daily smoking decreased among employees after the 1995 TCAA, supporting the hypothesis of the lowering impact of the amendment on daily smoking due to increased smoking cessation. No parallel change in daily smoking was found in the population without direct expose to ETS legislation (farmers, students, housewives, pensioners or unemployed). Exposure to ETS decreased markedly among non-smokers at work after the 1995 TCAA. The 1976 TCA and the 1995 TCAA were useful in controlling smoking initiation and cessation, but their impact was not equal across the population groups. The results of this study strongly suggested that tobacco control policies markedly contribute to the decrease in smoking and in exposure to environmental tobacco smoke.
  • Penninkilampi-Kerola, Varpu (Helsingin yliopisto, 2006)
    Objective: The aim of the present study was to examine co-twin dependence and its impact on twins' social contacts, leisure-time activities and psycho-emotional well-being. The role of co-twin dependence was also examined as a moderator of genetic and environmental influences on alcohol use in adolescence and in early adulthood. Methods: The present report is based on the Finnish Twin Cohort Study (FinnTwin16), a population-based study of five consecutive birth cohorts of Finnish twins born in the years 1975-1979. Baseline assessments were collected through mailed questionnaires, within two months of the twins' sixteenth birthday yielding replies from 5563 twin individuals. All respondent twins were sent follow-up questionnaires at ages of 17, 18½, and in early adulthood, when twins were 22-27 years old. Measures: The questionnaires included a survey of health habits and attitudes, a symptom checklist and questions about twins' relationships with parents, peers and co-twin. Measures used were twins' self-reports of their own dependence and their co-twin's dependence at age 16, reports of twins' leisure-time activities and social contacts, alcohol use, psychological distress and somatic symptoms both in adolescence and in early adulthood. Results: In the present study 25.6% of twins reported dependence on their co-twin. There were gender and zygosity differences in dependence, females and MZ twins were more likely to report dependence than males and DZ twins. Co-twin dependence can be viewed on one hand as an individual characteristic, but on the other hand as a pattern of dyadic interaction that is mutually regulated and reciprocal. Most of the twins (80.7%) were either concordantly co-twin dependent or concordantly co-twin independent. The associations of co-twin dependence with twins' social interactions and psycho-emotional characteristics were relatively consistent both in adolescence and in early adulthood. Dependence was related to higher contact frequency and a higher proportion of shared leisure-time activities between twin siblings at the baseline and the follow-up. Additionally co-twin dependence was associated with elevated levels of psycho-emotional distress and somatic complaints, especially in adolescence. In the framework of gene-environment interaction, these results suggest that the genetic contribution to individual differences in drinking patterns is dependent on the nature of the pair-wise relationship of twin siblings. Conclusions: The results of this study indicate that co-twin dependence is a genuine feature of the co-twin relationship and shows the importance of studying the impact of various features of co-twin relationships on individual twins' social and psycho-emotional life and well-being. Our study also offers evidence that differences in inter-personal relationships contribute to the effects of genetic propensities.
  • Virtanen, Anni (Helsingin yliopisto, 2015)
    High coverage amongst those at risk and a high attendance rate are essential in achieving a good impact in a cervical cancer screening programme. In Finland, attendance in the programme is approximately 70% with a slight decreasing trend. There is wide variation in the current invitation practice between municipalities. The introduction of human papillomavirus (HPV) testing in cervical cancer screening has brought about a new possible means of improving attendance rates, as HPV-testing can be performed on self-collected samples. This offers the opportunity to supply sampling devices directly to the homes of the women (self-sampling). The aim of this study was to investigate the effects and feasibility of using self-taken samples for HPV-testing to conduct cervical cancer screening of non-attendees to the Finnish cervical screening programme. The effect on attendance to the screening programme, on overall screening test coverage (including also testing outside the screening programme), on the yield of precancerous lesions detected by screening and on the costs of a screening programme were assessed, as were women s views on this new screening modality. The effects of self-sampling were first studied as a first reminder (i.e. among non-attendees after the primary invitation) in a randomized setting in comparison to a reminder letter, and then in a non-randomized setting as a second reminder after two invitation letters. As a first reminder to non-attendees after the primary invitation, a self-sampling test resulted in somewhat higher attendance than a reminder letter. The difference was small, and in terms of resulting costs (price per extra screened woman and price per detected CIN2+ lesion), a reminder letter with a pre-assigned appointment time is a more feasible choice than a self-sampling test. However, self-sampling can be used to increase screening attendance as a second reminder after two invitation letters. Overall attendance rates increased by 4-8%, and the combined effect of reminder letters and self-sampling showed a 12-23% increase. The yield of detected CIN2+ lesions increased by 25-33% with two reminders. As opportunistic screening is very common in Finland, the increase in overall test coverage remained smaller than the increase in the uptake to the programme. Based on a questionnaire study conducted alongside self-sampling, self-sampling at home helps to overcome both practical and emotional barriers to traditional screening. Women who took part in screening by self-sampling reported mainly positive experiences, but negative experiences were more common among women with a mother tongue other than Finnish or Swedish. The invitation protocol preceding the self-sampling option must be carefully arranged to achieve optimal attendance. A total attendance of well over 80% is achievable in the national programme if personal invitations and reminder letters to non-attendees are sent, scheduled appointments are used in both letters and self-sampling tests are sent to those women who still do not attend.
  • Koski, Anniina (Helsingin yliopisto, 2012)
    Gene therapy with oncolytic adenoviruses is a promising novel treatment modality for cancer. Adenoviruses have shown excellent safety and tolerability in clinical studies, but their efficacy still needs improvements, particularly when systemic administration is used. Problems related to systemic administration include natural adenoviral tropism to the liver through virus interaction with soluble coagulation factors in circulation and direct viral binding to cellular HSPG in the liver. The purpose of this thesis was to improve systemic administration and efficacy and safety of adenovirus treatments for cancer. We showed that ablation of vitamin K-dependent coagulation factors resulted in reduced liver transduction after intravenous administration to tumor-bearing mice. Further, combination of this with platelet depletion and inhibition of virus uptake to liver macrophages resulted in enhanced tumor-to-liver ratio of viral gene expression. We also constructed an adenovirus that has a mutation in the capsid fiber KKTK region to abolish interactions with liver cells through HSPG binding and a chimeric fiber knob from serotype 3 to enhance tumor cell transduction. The virus exhibited reduced liver tropism after systemic administration to mice. This virus was also investigated together with alterations of coagulation factor availability and these pathways of liver transduction were found to be separate and may work in an additive fashion. Preclinical studies have shown that adjuvant use of the calcium channel blockers can improve the efficacy of oncolytic adenoviruses in cancer gene therapy. We investigated the calcium channel blocker verapamil in combination with oncolytic adenovirus treatments of advanced cancer patients in the context of an Advanced Therapy Access Program (ATAP). Verapamil resulted in elevated serum viral titers after treatments, compared to non-randomized retrospectively matched controls, which suggests enhanced viral spread and release in the tumors. The frequency or severity of adverse events was not increased by verapamil. Therefore, verapamil seems a safe adjuvant of oncolytic adenovirus treatments and able to enhance viral kinetics. However, the effect of the adjuvant treatment with regard to treatment efficacy should be determined in a randomized clinical trial. Arming adenoviruses with immunostimulatory molecules is a promising way to boost antitumoral immune responses and thus enhance the overall treatment efficacy. We constructed Ad5/3-D24-GMCSF, an oncolytic adenovirus with a 5/3 chimeric capsid, encoding for the immunostimulatory cytokine GM-CSF. In preclinical experiments Ad5/3-D24-GMCSF displayed strong oncolytic potential, good tumor-selectivity and potent antitumor efficacy. 21 advanced cancer patients were treated with Ad5/3-D24-GMCSF in the context of ATAP. Treatments were well tolerated, with generally only mild or moderate adverse events. Intriguing signs of possible treatment benefits were also recorded. Further, signs of induction of antiviral and antitumoral immune responses were observed. Therefore Ad5/3-D24-GMCSF is a promising agent for treatment of cancer and clinical Phase I and I/II trials have been initialized for further analysis of this agent.
  • Simojoki, Kaarlo (Helsingin yliopisto, 2013)
    The purpose of this study was to investigate whether pharmacological or clinical management methods could improve patients' adherence to treatment and reduce the resource burden, thus improving treatment effectiveness. Finland was the first country in Europe to use buprenorphine-naloxone combination medication as part of 0pioid maintenance treatment (OMT), which was expected to have lower potential for diversion into the drug market. The study investigated whether the transition from mono-buprenorphine to buprenorphine-naloxone combination would cause adverse events or lower patient compliance. One way to reduce the diversion of buprenorphine medication is to crush the tablet when administering it, this has not been studied earlier, and it was investigated whether crushing mono-buprenorphine tablets would influence the kinetics and serum levels of buprenorphine, or whether patients would have adverse events following the use of crushed tablets. One main problem in OMT has been patient compliance and adherence to treatment. One main component has been visually supervised urine drug screens. Thus it was investigated whether a new unsupervised screening method would affect urine testing reliability, patient compliance, and the time/resources used by personnel in screening. The large buprenorphine abuse problem in Finland provides good possibilities for being able to study the abuse. A seven-year follow-up study evaluated the trends in street buprenorphine prices, intravenous abuse doses, and its abuse potential in Finland. The studies showed that the use of the new buprenorphine-naloxone combination product is as safe as mono-buprenorphine alone, and that no dose adjustments are needed during medication change. Crushing of the mono-buprenorphine tablet did not affect serum levels or buprenorphine kinetics, and the study subjects did not experience more or less adverse events than the control group. It was concluded that crushing is a safe and effective management for patients with high risk of medication abuse or diversion. The study with the new marker-based urine drug screen indicated that the new method did not jeopardize the safe and reliable assessment of concomitant drug use. Both patients and medical staff thought it was more comfortable than the traditional visually controlled screen. The new method saved considerable time previously spent on controlling the screen. So it was concluded that the new screening method improves patient compliance, reduces the burden of the control time and thus may increase the effectiveness of the treatment. The long-term follow-up study revealed that the street price of the new combination product is significantly less than of the mono-buprenorphine product and that the price difference remained the same during the follow-up period. Thus it was concluded that the abuse potential of the combination product is less than that of mono-buprenorphine. The studies demonstrate that there are several effective methods for reducing the abuse of OMT medications, and that patient compliance and thus the outcomes of treatment can both be improved. These methods should be used broadly in the clinical management of OMT.