Helicobacter pylori in Vammala, Finland: seroepidemiological studies and a population-based ‘screen-and-treat’ programme

Helicobacter pylorin (helikobakteeri) tartunta saadaan yleensä lapsena ja tauti jää tavallisesti pysyväksi ilman täsmähoitoa. Onnistunut hoito parantaa pysyvästi helikobakteerista aiheutuvan mahan haavataudin ja näyttää ehkäisevän mahalaukun pahanlaatuisten muutosten kehittymistä. Aloitimme Vammalassa terveyskeskuksessa toteutetun kansainvälisesti ainutlaatuisen väestöpohjaisen helikobakteeritulehduksen seulonta- ja hoito-ohjelman pilottitutkimuksella 1994. 1996 kaikki 15-40-vuotiaat ja 1997-2000 15- ja 45-vuotiaat vammalalaiset kutsuttiin verinäyteseulontaan. Yhteensä 4626 henkilöä (75% kutsutuista) osallistui seulontaan. Vasta-ainepositiivisille tarjottiin helikobakteeritulehduksen lopettava lääkekuuri. Toiminnan seurauksena helikobakteeritulehduksen esiintyvyyden laskettiin vähentyneen 12%:sta 4%:iin 15-40-vuotiaiden ikäryhmässä. Tutkimme myös helikobakteerivasta-ainepositiivisten ja -negatiivisten eroja sekä helikobakteeritulehduksen riskitekijöitä kyselytutkimuksella. Lapsuudenkodin asumisahtauden, äidin matalan koulutusasteen, tupakoinnin, alkoholinkäytön, huonojen asunto-olojen ja ylävatsavaivoista johtuvien sairauslomien todettiin liittyvän helikobakteeritulehdukseen monimuuttuja-analyysissa. Tutkimme seulontaohjelmassa käyttämiemme IgG- ja IgA-luokan helikobakteeri-vasta-ainetestien luotettavuutta eri ikäryhmissä ottaen huomioon atrofisen gastriitin esiintyvyyden. 561 kliinisin perustein gastroskopoidun potilaan aineistossa IgG-testi osoittautui erittäin herkäksi kaikissa ikäryhmissä (99%). Tarkkuus oli myös vanhemmissa ikäryhmissä hyvä (97-93%), kun atrofista gastriittia sairastavat suljettiin pois. IgA- ja CagA-helikobakteerivasta-aineiden on todettu liittyvän lisääntyneeseen mahahaava- ja mahasyöpäriskiin. Analysoimme 560 henkilön pariseeruminäytteet, jotka oli otettu kahden vuosikymmenen välein, ja totesimme, että IgA-vasta-aineiden esiintyvyyden lisääntyyminen iän myötä johtuu paitsi syntymäajankohdasta ja uusista infektioista myös IgA-vasta-ainetasojen kohoamisesta helikobakteeritulehduksen aikana. Selvitimme myös CagA-vasta-ainetasojen muuttumista analysoimalla seeruminäytteet, jotka oli otettu kahden vuosikymmenen välein. Totesimme, että samanaikaisesti kun helikobakteerin esiintyvyys väestössä on alentunut, erityisesti CagA-positiiviset infektiot ovat vähentyneet. Tutkimuksemme osoittaa, että Suomessa terveyskeskuksen yhteydessä voidaan toteuttaa näin laajamittainen seulonta- ja hoito-ohjelma, johon suomalaiset osallistuvat aktiivisesti. Nähtäväksi jää, kuinka paljon ohjelma kykeni vähentämään helikobakteeritulehdukseen liittyviä myöhäisseuraamuksia.

Variation in tracheid cross-sectional dimensions and wood viscoelasticity extent and control methods

Printing papers have been the main product of the Finnish paper industry. To improve properties and economy of printing papers, controlling of tracheid cross-sectional dimensions and wood viscoelasticity are examined in this study. Controlling is understood as any procedure which yields raw material classes with distinct properties and small internal variation. Tracheid cross-sectional dimensions, i.e., cell wall thickness and radial and tangential diameters can be controlled with methods such as sorting wood into pulpwood and sawmill chips, sorting of logs according to tree social status and fractionation of fibres. These control methods were analysed in this study with simulations, which were based on measured tracheid cross-sectional dimensions. A SilviScan device was used to measure the data set from five Norway spruce (Picea abies) and five Scots pine (Pinus sylvestris) trunks. The simulation results indicate that the sawmill chips and top pulpwood assortments have quite similar cross-sectional dimensions. Norway spruce and Scots pine are on average also relatively similar in their cross-sectional dimensions. The distributions of these species are somewhat different, but from a practical point of view, the differences are probably of minor importance. The controlling of tracheid cross-sectional dimensions can be done most efficiently with methods that can separate fibres into earlywood and latewood. Sorting of logs or partitioning of logs into juvenile and mature wood were markedly less efficient control methods than fractionation of fibres. Wood viscoelasticity affects energy consumption in mechanical pulping, and is thus an interesting control target when improving energy efficiency of the process. A literature study was made to evaluate the possibility of using viscoelasticity in controlling. The study indicates that there is considerable variation in viscoelastic properties within tree species, but unfortunately, the viscoelastic properties of important raw material lots such as top pulpwood or sawmill chips are not known. Viscoelastic properties of wood depend mainly on lignin, but also on microfibrillar angle, width of cellulose crystals and tracheid cross-sectional dimensions.

Effects of dietary phosphorus and calcium-to-phosphorus ratio on calcium and bone metabolism in healthy 20- to 43-year-old Finnish women

Dietary habits have changed during the past decades towards an increasing consumption of processed foods, which has notably increased not only total dietary phosphorus (P) intake, but also intake of P from phosphate additives. While the intake of calcium (Ca) in many Western countries remains below recommended levels (800 mg/d), the usual daily P intake in a typical Western diet exceeds by 2- to 3-fold the dietary guidelines (600 mg/d). The effects of high P intake in healthy humans have been investigated seldom. In this thesis healthy 20- to 43-year-old women were studied. In the first controlled study (n = 14), we examined the effects of P doses, and in a cross-sectional study (n = 147) the associations of habitual P intakes with Ca and bone metabolism. In this same cross-sectional study, we also investigated whether differences exist between dietary P originating from natural P sources and phosphate additives. The second controlled study (n = 12) investigated whether by increasing the Ca intake, the effects of a high P intake could be reduced. The associations of habitual dietary calcium-to-phosphorus ratios (Ca:P ratio) with Ca and bone metabolism were determined in a cross-sectional study design (n = 147). In the controlled study, the oral intake of P doses (495, 745, 1245 and 1995 mg/d) with a low Ca intake (250 mg/d) increased serum parathyroid hormone (S-PTH) concentration in a dose-dependent manner. In addition, the highest P dose decreased serum ionized calcium (S-iCa) concentration and bone formation and increased bone resorption. In the second controlled study with a dietary P intake of 1850 mg/d, by increasing the Ca intake from 480 mg/d to 1080 mg/d and then to 1680 mg/d, the S-PTH concentration decreased, the S-iCa concentration increased and bone resorption decreased dose-dependently. However, not even the highest Ca intake could counteract the effect of high dietary P on bone formation, as indicated by unchanged bone formation activity. In the cross-sectional studies, a higher habitual dietary P intake (>1650 mg/d) was associated with lower S-iCa and higher S-PTH concentrations. The consumption of phosphate additive-containing foods was associated with a higher S-PTH concentration. Moreover, habitual low dietary Ca:P ratios (≤0.50, molar ratio) were associated with higher S-PTH concentrations and 24-h urinary Ca excretions, suggesting that low dietary Ca:P ratios may interfere with homeostasis of Ca metabolism and increase bone resorption. In summary, excessive dietary P intake in healthy Finnish women seems to be detrimental to Ca and bone metabolism, especially when dietary Ca intake is low. The results indicate that by increasing dietary Ca intake to the recommended level, the negative effects of high P intake could be diminished, but not totally prevented. These findings imply that phosphate additives may be more harmful than natural P. Thus, reduction of an excessively high dietary P intake is also beneficial for healthy individuals.

Substance flow analysis in Finland : Four case studies on N and P flows

Nitrogen (N) and phosphorus (P) are essential elements for all living organisms. However, in excess, they contribute to several environmental problems such as aquatic and terrestrial eutrophication. Globally, human action has multiplied the volume of N and P cycling since the onset of industrialization. The multiplication is a result of intensified agriculture, increased energy consumption and population growth. Industrial ecology (IE) is a discipline, in which human interaction with the ecosystems is investigated using a systems analytical approach. The main idea behind IE is that industrial systems resemble ecosystems, and, like them, industrial systems can then be described using material, energy and information flows and stocks. Industrial systems are dependent on the resources provided by the biosphere, and these two cannot be separated from each other. When studying substance flows, the aims of the research from the viewpoint of IE can be, for instance, to elucidate the ways how the cycles of a certain substance could be more closed and how the flows of a certain substance could be decreased per unit of production (= dematerialization). In Finland, N and P are studied widely in different ecosystems and environmental emissions. A holistic picture comparing different societal systems is, however, lacking. In this thesis, flows of N and P were examined in Finland using substance flow analysis (SFA) in the following four subsystems: I) forest industry and use of wood fuels, II) food production and consumption, III) energy, and IV) municipal waste. A detailed analysis at the end of the 1990s was performed. Furthermore, historical development of the N and P flows was investigated in the energy system (III) and the municipal waste system (IV). The main research sources were official statistics, literature, monitoring data, and expert knowledge. The aim was to identify and quantify the main flows of N and P in Finland in the four subsystems studied. Furthermore, the aim was to elucidate whether the nutrient systems are cyclic or linear, and to identify how these systems could be more efficient in the use and cycling of N and P. A final aim was to discuss how this type of an analysis can be used to support decision-making on environmental problems and solutions. Of the four subsystems, the food production and consumption system and the energy system created the largest N flows in Finland. For the creation of P flows, the food production and consumption system (Paper II) was clearly the largest, followed by the forest industry and use of wood fuels and the energy system. The contribution of Finland to N and P flows on a global scale is low, but when compared on a per capita basis, we are one of the largest producers of these flows, with relatively high energy and meat consumption being the main reasons. Analysis revealed the openness of all four systems. The openness is due to the high degree of internationality of the Finnish markets, the large-scale use of synthetic fertilizers and energy resources and the low recycling rate of many waste fractions. Reduction in the use of fuels and synthetic fertilizers, reorganization of the structure of energy production, reduced human intake of nutrients and technological development are crucial in diminishing the N and P flows. To enhance nutrient recycling and replace inorganic fertilizers, recycling of such wastes as wood ash and sludge could be promoted. SFA is not usually sufficiently detailed to allow specific recommendations for decision-making to be made, but it does yield useful information about the relative magnitude of the flows and may reveal unexpected losses. Sustainable development is a widely accepted target for all human action. SFA is one method that can help to analyse how effective different efforts are in leading to a more sustainable society. SFA's strength is that it allows a holistic picture of different natural and societal systems to be drawn. Furthermore, when the environmental impact of a certain flow is known, the method can be used to prioritize environmental policy efforts.

Randomised Evaluation of New Technologies within the Population‐Based Cervical Cancer Screening Programme in Finland: Cross‐Sectional Performance and Validity

A randomised and population-based screening design with new technologies has been applied to the organised cervical cancer screening programme in Finland. In this experiment the women invited to routine five-yearly screening are individually randomised to be screened with automation-assisted cytology, human papillomavirus (HPV) test or conventional cytology. By using the randomised design, the ultimate aim is to assess and compare the long-term outcomes of the different screening regimens. The primary aim of the current study was to evaluate, based on the material collected during the implementation phase of the Finnish randomised screening experiment, the cross-sectional performance and validity of automation-assisted cytology (Papnet system) and primary HPV DNA testing (Hybrid Capture II assay for 13 oncogenic HPV types) within service screening, in comparison to conventional cytology. The parameters of interest were test positivity rate, histological detection rate, relative sensitivity, relative specificity and positive predictive value. Also, the effect of variation in performance by screening laboratory on age-adjusted cervical cancer incidence was assessed. Based on the cross-sectional results, almost no differences were observed in the performance of conventional and automation-assisted screening. Instead, primary HPV screening found 58% (95% confidence interval 19-109%) more cervical lesions than conventional screening. However, this was mainly due to overrepresentation of mild- and moderate-grade lesions and, thus, is likely to result in overtreatment since a great deal of these lesions would never progress to invasive cancer. Primary screening with an HPV DNA test alone caused substantial loss in specificity in comparison to cytological screening. With the use of cytology triage test, the specificity of HPV screening improved close to the level of conventional cytology. The specificity of primary HPV screening was also increased by increasing the test positivity cutoff from the level recommended for clinical use, but the increase was more modest than the one gained with the use of cytology triage. The performance of the cervical cancer screening programme varied widely between the screening laboratories, but the variation in overall programme effectiveness between respective populations was more marginal from the very beginning of the organised screening activity. Thus, conclusive interpretations on the quality or success of screening should not be based on performance parameters only. In the evaluation of cervical cancer screening the outcome should be selected as closely as possible to the true measure of programme effectiveness, which is the number of invasive cervical cancers and subsequent deaths prevented in the target population. The evaluation of benefits and adverse effects of each new suggested screening technology should be performed before the technology becomes an accepted routine in the existing screening programme. At best, the evaluation is performed randomised, within the population and screening programme in question, which makes the results directly applicable to routine use.

Macroseismology as a Component of Seismicity Assessments in an Intraplate Region: Studies of Northern Europe with Emphasis on Finland

This work focuses on the role of macroseismology in the assessment of seismicity and probabilistic seismic hazard in Northern Europe. The main type of data under consideration is a set of macroseismic observations available for a given earthquake. The macroseismic questionnaires used to collect earthquake observations from local residents since the late 1800s constitute a special part of the seismological heritage in the region. Information of the earthquakes felt on the coasts of the Gulf of Bothnia between 31 March and 2 April 1883 and on 28 July 1888 was retrieved from the contemporary Finnish and Swedish newspapers, while the earthquake of 4 November 1898 GMT is an example of an early systematic macroseismic survey in the region. A data set of more than 1200 macroseismic questionnaires is available for the earthquake in Central Finland on 16 November 1931. Basic macroseismic investigations including preparation of new intensity data point (IDP) maps were conducted for these earthquakes. Previously disregarded usable observations were found in the press. The improved collection of IDPs of the 1888 earthquake shows that this event was a rare occurrence in the area. In contrast to earlier notions it was felt on both sides of the Gulf of Bothnia. The data on the earthquake of 4 November 1898 GMT were augmented with historical background information discovered in various archives and libraries. This earthquake was of some concern to the authorities, because extra fire inspections were conducted in three towns at least, i.e. Tornio, Haparanda and Piteå, located in the centre of the area of perceptibility. This event posed the indirect hazard of fire, although its magnitude around 4.6 was minor on the global scale. The distribution of slightly damaging intensities was larger than previously outlined. This may have resulted from the amplification of the ground shaking in the soft soil of the coast and river valleys where most of the population was found. The large data set of the 1931 earthquake provided an opportunity to apply statistical methods and assess methodologies that can be used when dealing with macroseismic intensity. It was evaluated using correspondence analysis. Different approaches such as gridding were tested to estimate the macroseismic field from the intensity values distributed irregularly in space. In general, the characteristics of intensity warrant careful consideration. A more pervasive perception of intensity as an ordinal quantity affected by uncertainties is advocated. A parametric earthquake catalogue comprising entries from both the macroseismic and instrumental era was used for probabilistic seismic hazard assessment. The parametric-historic methodology was applied to estimate seismic hazard at a given site in Finland and to prepare a seismic hazard map for Northern Europe. The interpretation of these results is an important issue, because the recurrence times of damaging earthquakes may well exceed thousands of years in an intraplate setting such as Northern Europe. This application may therefore be seen as an example of short-term hazard assessment.

Computational fluid dynamics simulations in aerosol and nucleation studies

Nucleation is the first step in the formation of a new phase inside a mother phase. Two main forms of nucleation can be distinguished. In homogeneous nucleation, the new phase is formed in a uniform substance. In heterogeneous nucleation, on the other hand, the new phase emerges on a pre-existing surface (nucleation site). Nucleation is the source of about 30% of all atmospheric aerosol which in turn has noticeable health effects and a significant impact on climate. Nucleation can be observed in the atmosphere, studied experimentally in the laboratory and is the subject of ongoing theoretical research. This thesis attempts to be a link between experiment and theory. By comparing simulation results to experimental data, the aim is to (i) better understand the experiments and (ii) determine where the theory needs improvement. Computational fluid dynamics (CFD) tools were used to simulate homogeneous onecomponent nucleation of n-alcohols in argon and helium as carrier gases, homogeneous nucleation in the water-sulfuric acid-system, and heterogeneous nucleation of water vapor on silver particles. In the nucleation of n-alcohols, vapor depletion, carrier gas effect and carrier gas pressure effect were evaluated, with a special focus on the pressure effect whose dependence on vapor and carrier gas properties could be specified. The investigation of nucleation in the water-sulfuric acid-system included a thorough analysis of the experimental setup, determining flow conditions, vapor losses, and nucleation zone. Experimental nucleation rates were compared to various theoretical approaches. We found that none of the considered theoretical descriptions of nucleation captured the role of water in the process at all relative humidities. Heterogeneous nucleation was studied in the activation of silver particles in a TSI 3785 particle counter which uses water as its working fluid. The role of the contact angle was investigated and the influence of incoming particle concentrations and homogeneous nucleation on counting efficiency determined.

Cystatin C, a measure of renal function, as prognostic risk marker in acute heart failure : Studies on the cardiorenal syndrome

Acute heart failure (AHF) is a complex syndrome associated with exceptionally high mortality. Still, characteristics and prognostic factors of contemporary AHF patients have been inadequately studied. Kidney function has emerged as a very powerful prognostic risk factor in cardiovascular disease. This is believed to be the consequence of an interaction between the heart and kidneys, also termed the cardiorenal syndrome, the mechanisms of which are not fully understood. Renal insufficiency is common in heart failure and of particular interest for predicting outcome in AHF. Cystatin C (CysC) is a marker of glomerular filtration rate with properties making it a prospective alternative to the currently used measure creatinine for assessment of renal function. The aim of this thesis is to characterize a representative cohort of patients hospitalized for AHF and to identify risk factors for poor outcome in AHF. In particular, the role of CysC as a marker of renal function is evaluated, including examination of the value of CysC as a predictor of mortality in AHF. The FINN-AKVA (Finnish Acute Heart Failure) study is a national prospective multicenter study conducted to investigate the clinical presentation, aetiology and treatment of, as well as concomitant diseases and outcome in, AHF. Patients hospitalized for AHF were enrolled in the FINN-AKVA study, and mortality was followed for 12 months. The mean age of patients with AHF is 75 years and they frequently have both cardiovascular and non-cardiovascular co-morbidities. The mortality after hospitalization for AHF is high, rising to 27% by 12 months. The present study shows that renal dysfunction is very common in AHF. CysC detects impaired renal function in forty percent of patients. Renal function, measured by CysC, is one of the strongest predictors of mortality independently of other prognostic risk markers, such as age, gender, co-morbidities and systolic blood pressure on admission. Moreover, in patients with normal creatinine values, elevated CysC is associated with a marked increase in mortality. Acute kidney injury, defined as an increase in CysC within 48 hours of hospital admission, occurs in a significant proportion of patients and is associated with increased short- and mid-term mortality. The results suggest that CysC can be used for risk stratification in AHF. Markers of inflammation are elevated both in heart failure and in chronic kidney disease, and inflammation is one of the mechanisms thought to mediate heart-kidney interactions in the cardiorenal syndrome. Inflammatory cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) correlate very differently to markers of cardiac stress and renal function. In particular, TNF-α showed a robust correlation to CysC, but was not associated with levels of NT-proBNP, a marker of hemodynamic cardiac stress. Compared to CysC, the inflammatory markers were not strongly related to mortality in AHF. In conclusion, patients with AHF are elderly with multiple co-morbidities, and renal dysfunction is very common. CysC demonstrates good diagnostic properties both in identifying impaired renal function and acute kidney injury in patients with AHF. CysC, as a measure of renal function, is also a powerful prognostic marker in AHF. CysC shows promise as a marker for assessment of kidney function and risk stratification in patients hospitalized for AHF.

Political Risk in Credit Evaluation: Empirical Studies and Survey Results

Financing trade between economic agents located in different countries is affected by many types of risks, resulting from incomplete information about the debtor, the problems of enforcing international contracts, or the prevalence of political and financial crises. Trade is important for economic development and the availability of trade finance is essential, especially for developing countries. Relatively few studies treat the topic of political risk, particularly in the context of international lending. This thesis explores new ground to identify links between political risk and international debt defaults. The core hypothesis of the study is that the default probability of debt increases with increasing political risk in the country of the borrower. The thesis consists of three essays that support the hypothesis from different angles of the credit evaluation process. The first essay takes the point of view of an international lender assessing the credit risk of a public borrower. The second investigates creditworthiness assessment of companies. The obtained results are substantiated in the third essay that deals with an extensive political risk survey among finance professionals in developing countries. The financial instruments of core interest are export credit guaranteed debt initiated between the Export Credit Agency of Finland and buyers in 145 countries between 1975 and 2006. Default events of the foreign credit counterparts are conditioned on country-specific macroeconomic variables, corporate-specific accounting information as well as political risk indicators from various international sources. Essay 1 examines debt issued to government controlled institutions and conditions public default events on traditional macroeconomic fundamentals, in addition to selected political and institutional risk factors. Confirming previous research, the study finds country indebtedness and the GDP growth rate to be significant indicators of public default. Further, it is shown that public defaults respond to various political risk factors. However, the impact of the risk varies between countries at different stages of economic development. Essay 2 proceeds by investigating political risk factors as conveivable drivers of corporate default and uses traditional accounting variables together with new political risk indicators in the credit evaluation of private debtors. The study finds links between corporate default and leverage, as well as between corporate default and the general investment climate and measeures of conflict in the debtor country. Essay 3 concludes the thesis by offering survey evidence on the impact of political risk on debt default, as perceived and experienced by 103 finance professionals in 38 developing countries. Taken together, the results of the thesis suggest that various forms of political risk are associated with international debt defaults and continue to pose great concerns for both international creditors and borrowers in developing countries. The study provides new insights on the importance of variable selection in country risk analysis, and shows how political risk is actually perceived and experienced in the riskier, often lower income countries of the global economy.

Time Dimension in Consumers’ Image Construction Processes: Introducing Image Heritage and Image-in-use

This paper focuses on the time dimension in consumers’ image construction processes. Two new concepts are introduced to cover past consumer experiences about the company – image heritage, and the present image construction process - image-in-use. Image heritage and image-in-use captures the dynamic, relational, social, and contextual features of corporate image construction processes. Qualitative data from a retailing context were collected and analysed following a grounded theory approach. The study demonstrates that consumers’ corporate images have long roots in past experiences. Understanding consumers’ image heritage provides opportunities for understanding how consumers might interpret management initiatives and branding activities in the present.