Genetically Engineered Oncolytic Adenoviruses for the Treatment of Kidney and Breast Cancer

Metastatic kidney and breast cancer are devastating diseases currently lacking efficient treatment options. One promising developmental approach in cancer treatment are oncolytic adenoviruses, which have demonstrated excellent safety in many clinical trials. However, antitumor efficacy needs to be improved in order to make oncolytic viruses a viable treatment alternative. To be able to follow oncolytic virus replication in vivo, we set up a non-invasive imaging system based on coinjection of a replication deficient luciferase expressing virus and a replication competent virus. The system was validated in vitro and in vivo and used in other projects of the thesis. In another study we showed that capsid modifications on adenoviruses result in enhanced gene transfer and increased oncolytic effect on renal cancer cells in vitro. Moreover, capsid modified oncolytic adenoviruses demonstrated significantly improved antitumor efficacy in murine kidney cancer models. To transcriptionally target kidney cancer tissue we evaluated two hypoxia response elements for their usability as tissue specific promoters using a novel dual luciferase imaging system. Based on the results of the promoter evaluation and the studies on capsid modifications, we constructed a transcriptionally and transductionally targeted oncolytic adenovirus armed with an antiangiogenic transgene for enhanced renal cell cancer specificity and improved antitumor efficacy. This virus exhibited kidney cancer specific replication and significantly improved antitumor effect in a murine model of intraperitoneal disseminated renal cell cancer. Cancer stem cells are thought to be resistant to conventional cancer drugs and might play an important role in breast cancer relapse and the formation of metastasis. Therefore, we examined if capsid modified oncolytic adenoviruses are able to kill these cells proposed to be breast cancer initiating. Efficient oncolytic effect and significant antitumor efficacy on tumors established with breast cancer initiating cells was observed, suggesting that oncolytic adenoviruses might be able to prevent breast cancer relapse and could be used in the treatment of metastatic disease. In conclusion, the results presented in this thesis suggest that genetically engineered oncolytic adenoviruses have great potential in the treatment of metastatic kidney and breast cancer.

Physical characterization of plastic surfaces in wearing and cleanability research

Plastic surfaces are a group of materials used for many purposes. The present study was focused on methods for investigation of surface topography, wearing and cleanability of polyvinyl chloride (PVC) model surfaces and industrial plastic surfaces. Contact profilometry, scanning electron microscopy (SEM) and atomic force microscopy (AFM) are powerful methods for studying the topography of plastic surfaces. Although they have their own limitations, they are together an effective tool providing useful information on surface topography, especially when studying laboratory-made PVC model surfaces with known chemical compositions and structures. All examined laboratory-made PVC plastic surfaces examined in this work could be considered as smooth according to both AFM and profilometer measurements because height differences are in the nanoscale on every surface. Industrial plastic surfaces are a complex group of materials because of their chemical and topographical heterogeneity, but they are nevertheless important reference materials when developing cleaning and wearing methods. According to the results of this study the Soiling and Wearing Drum and the Frick-Taber methods are very useful when simulating three-body wearing of plastic surfaces. Both the investigated wearing methods can be used to compare the wearing of different plastic materials using appropriate evaluation methods of wearing and industrial use. In this study, physical methods were developed and adapted from other fields of material research to cleanability studies. The thesis focuses on the methodology for investigating the cleanability of plastic surfaces under realistic conditions, where surface topography and the effect of wear cleanability were among the major topics. A colorimetric method proved to be suitable for examining the cleanability of the industrial plastic surfaces. The results were utilized to evaluate the relationship between cleanability and the surface properties of plastic surfaces. The devices and methods used in the work can be utilized both in material research and product development.

Cereulide producing B. cereus and amylosin producing B. subtilis and B. mojavensis : characterization of strains and toxigenicities

B. cereus is one of the most frequent occurring bacteria in foods . It produces several heat-labile enterotoxins and one stable non-protein toxin, cereulide (emetic), which may be pre-formed in food. Cereulide is a heat stable peptide whose structure and mechanism of action were in the past decade elucidated. Until this work, the detection of cereulide was done by biological assays. With my mentors, I developed the first quantitative chemical assay for cereulide. The assay is based on liquid chromatography (HPLC) combined with ion trap mass spectrometry and the calibration is done with valinomycin and purified cereulide. To detect and quantitate valinomycin and cereulide, their [NH4+] adducts, m/z 1128.9 and m/z 1171 respectively, were used. This was a breakthrough in the cereulide research and became a very powerful tool of investigation. This tool made it possible to prove for the first time that the toxin produced by B. cereus in heat-treated food caused human illness. Until this thesis work (Paper II), cereulide producing B. cereus strains were believed to represent a homogenous group of clonal strains. The cereulide producing strains investigated in those studies originated mostly from food poisoning incidents. We used strains of many origins and analyzed them using a polyphasic approach. We found that the cereulide producing B. cereus strains are genetically and biologically more diverse than assumed in earlier studies. The strains diverge in the adenylate kinase (adk) gene (two sequence types), in ribopatterns obtained with EcoRI and PvuII (three patterns), tyrosin decomposition, haemolysis and lecithine hydrolysis (two phenotypes). Our study was the first demonstration of diversity within the cereulide producing strains of B. cereus. To manage the risk for cereulide production in food, understanding is needed on factors that may upregulate cereulide production in a given food matrix and the environmental factors affecting it. As a contribution towards this direction, we adjusted the growth environment and measured the cereulide production by strains selected for diversity. The temperature range where cereulide is produced was narrower than that for growth for most of the producer strains. Most cereulide was by most strains produced at room temperature (20 - 23ºC). Exceptions to this were two faecal isolates which produced the same amount of cereulide from 23 ºC up until 39ºC. We also found that at 37º C the choice of growth media for cereulide production differed from that at the room temperature. The food composition and temperature may thus be a key for understanding cereulide production in foods as well as in the gut. We investigated the contents of [K+], [Na+] and amino acids of six growth media. Statistical evaluation indicated a significant positive correlation between the ratio [K+]:[Na+] and the production of cereulide, but only when the concentrations of glycine and [Na+] were constant. Of the amino acids only glycine correlated positively with high cereulide production. Glycine is used worldwide as food additive (E 640), flavor modifier, humectant, acidity regulator, and is permitted in the European Union countries, with no regulatory quantitative limitation, in most types of foods. B. subtilis group members are endospore-forming bacteria ubiquitous in the environment, similar to B. cereus in this respect. Bacillus species other than B. cereus have only sporadically been identified as causative agents of food-borne illnesses. We found (Paper IV) that food-borne isolates of B. subtilis and B. mojavensis produced amylosin. It is possible that amylosin was the agent responsible for the food-borne illness, since no other toxic substance was found in the strains. This is the first report on amylosin production by strains isolated from food. We found that the temperature requirement for amylosin production was higher for the B. subtilis strain F 2564/96, a mesophilic producer, than for B. mojavensis strains eela 2293 and B 31, psychrotolerant producers. We also found that an atmosphere with low oxygen did not prevent the production of amylosin. Ready-to-eat foods packaged in micro-aerophilic atmosphere and/or stored at temperatures above 10 °C, may thus pose a risk when toxigenic strains of B. subtilis or B. mojavensis are present.

Defining Adequate Vitamin D Intake : Cross-sectional and Intervention Studies

D-vitamiini ylläpitää normaalia luun kasvua ja uudistumista koko elämän ajan. Suomessa, kuten monissa muissakin länsimaissa, väestön D-vitamiinitilanne on riittämätön – talvisin osalla jopa puutteellinen. Tässä väitöskirjassa on tutkittu, lisääkö D-vitamiini luumassan kertymistä kasvuiässä, ja ylläpitäkö D-vitamiini luuston tasapainoista aineenvaihduntaa aikuisiällä. Nämä vaikutukset saattavat ehkäisi osteoporoosin kehittymistä eri ikäkausina. Väitöskirjatyössä tutkittiin erisuuruisten D-vitamiinilisäysten vaikutuksia kolmessa eri ikäryhmässä, jotka olivat 11-12 -vuotiaat tytöt (N=228), 21-49 -vuotiaat miehet (N=54) ja 65-85 -vuotiaat naiset (N=52). Tutkittavat satunnaistettiin ryhmiin, jotka nauttivat joko lumevalmistetta tai 5-20 µg D3-vitamiinia vitamiinilisänä. Tutkimukset olivat kaksoissokkoutettuja. Tutkimuksen aikana tutkittavilta otettiin paastoveri- ja virtsanäytteitä. Lisäksi he täyttivät tutkimuslomakkeen taustatietojen kartoittamiseksi sekä frekvenssikyselylomakkeen kalsiumin ja D-vitamiinin saannin selvittämiseksi. Tyttöjen luunmineraalitiheys (BMD) mitattiin DXA–laitteella ja miesten volumetrinen luuntiheys pQCT-menetelmällä. Näytteistä määritettiin mm. seerumin 25-hydroksi-D-vitamiinin (=S-25-OHD), lisäkilpirauhashormonin (=S-PTH) ja luun aineenvaihduntaa kuvaavien merkkiaineiden pitoisuuksia. Murrosikäisten tyttöjen poikkileikkaustutkimuksessa S-25-OHD- ja luun muodostusmerkkiaineen pitoisuudet vaihtelivat kuukausien välillä; suurimmat pitoisuudet mitattiin syyskuussa ja pienimmät maaliskuussa, mikä kuvastaa vuodenaikaisvaihtelua. Vastaava vaihtelu havaittiin lannerangan ja reisiluun BMD:ssä. D-vitamiinilisäyksellä oli myönteinen vaikutus tyttöjen luumassan lisääntymiseen. Suurin D-vitamiinilisä (10 µg/vrk) lisäsi luumassaa 17.2% enemmän reisiluussa ja 12.5% enemmän lannerangassa verrattuna lumevalmistetta nauttivien tyttöjen vastaaviin tuloksiin, mutta tulos riippui hoitomyöntyvyydestä. D-vitamiinin vaikutus luustoon välittyi vähentyneen luun hajotuksen kautta. Tutkimustuloksiin perustuen riittävä D-vitamiinin saanti murrosikäisille tytöille on 15 µg/vrk. D-vitamiinilisän vaikutus 65-85 -vuotiaiden naisten S-25-OHD-pitoisuuteen vakioitui kuudessa viikossa annoksen ollessa 5-20 µg/vrk. Näillä D-vitamiiniannoksilla ei saavutettu tavoiteltavaa S-25-OHD-pitoisuutta, joka on 80 nmol/l. Arvioimme, että 60 nmol/l -pitoisuuden, jota esiintyy kesäisin tämän ikäryhmän suomalaisilla, tämän ikäryhmän naiset saavuttaisivat 24 µg:n päivittäisellä D-vitamiinin saannilla. Terveillä miehillä havaittiin vuodenaikaisvaihtelu S-25-OHD- ja S-PTH-pitoisuudessa sekä luun hajotusta kuvaavassa merkkiainepitoisuudessa. Toisaalta vaihtelua ei havaittu radiuksen volumetrisessä luuntiheydessä eikä luun muodostusmerkkiaineen pitoisuudessa. Vuodenaikaisvaihtelu estettiin 17 µg:n päivittäisellä D-vitamiinin saannilla, mutta tämän ei havaittu vaikuttavan radiuksen luuntiheyteen kuusi kuukautta kestävän tutkimuksen aikana. Yhteenvetona todetaan, että D-vitamiinin saanti on edelleenkin riittämätöntä tutkimusten kohderyhmillä. Tämä näkyy S-25-OHD- ja PTH-pitoisuuden sekä luunaineenvaihduntaa kuvaavien merkkiaineiden vuodenaikaisvaihteluna, mikä on haitallista luuston hyvinvoinnille. D-vitamiinin saantia tulisi lisätä, jotta vähintäänkin riittävä D-vitamiinitilanne (S-25-OHD>50 nmol/l) tai mahdollisesti jopa tavoiteltava D-vitaminitilanne (S-25-OHD≥80 nmol/l) saavutettaisiin. Jotta D-vitamiinin saannin lisääminen olisi kaikissa ikäryhmissä mahdollista, on suunniteltava nykyistä enemmän D-vitamiinilla täydennettyjä elintarvikkeita.

Computational studies on new chemical species in the gas-phase and the solid-state.

There is intense activity in the area of theoretical chemistry of gold. It is now possible to predict new molecular species, and more recently, solids by combining relativistic methodology with isoelectronic thinking. In this thesis we predict a series of solid sheet-type crystals for Group-11 cyanides, MCN (M=Cu, Ag, Au), and Group-2 and 12 carbides MC2 (M=Be-Ba, Zn-Hg). The idea of sheets is then extended to nanostrips which can be bent to nanorings. The bending energies and deformation frequencies can be systematized by treating these molecules as an elastic bodies. In these species Au atoms act as an 'intermolecular glue'. Further suggested molecular species are the new uncongested aurocarbons, and the neutral Au_nHg_m clusters. Many of the suggested species are expected to be stabilized by aurophilic interactions. We also estimate the MP2 basis-set limit of the aurophilicity for the model compounds [ClAuPH_3]_2 and [P(AuPH_3)_4]^+. Beside investigating the size of the basis-set applied, our research confirms that the 19-VE TZVP+2f level, used a decade ago, already produced 74 % of the present aurophilic attraction energy for the [ClAuPH_3]_2 dimer. Likewise we verify the preferred C4v structure for the [P(AuPH_3)_4]^+ cation at the MP2 level. We also perform the first calculation on model aurophilic systems using the SCS-MP2 method and compare the results to high-accuracy CCSD(T) ones. The recently obtained high-resolution microwave spectra on MCN molecules (M=Cu, Ag, Au) provide an excellent testing ground for quantum chemistry. MP2 or CCSD(T) calculations, correlating all 19 valence electrons of Au and including BSSE and SO corrections, are able to give bond lengths to 0.6 pm, or better. Our calculated vibrational frequencies are expected to be better than the currently available experimental estimates. Qualitative evidence for multiple Au-C bonding in triatomic AuCN is also found.

Quantum Chemical Studies of Intermolecular Interactions

This thesis studies the intermolecular interactions in (i) boron-nitrogen based systems for hydrogen splitting and storage, (ii) endohedral complexes, A@C60, and (iii) aurophilic dimers. We first present an introduction of intermolecular interactions. The theoretical background is then described. The research results are summarized in the following sections. In the boron-nitrogen systems, the electrostatic interaction is found to be the leading contribution, as 'Coulomb Pays for Heitler and London' (CHL). For the endohedral complex, the intermolecular interaction is formulated by a one-center expansion of the Coulomb operator 1/rab. For the aurophilic attraction between two C2v monomers, a London-type formula was derived by fully accounting for the anisotropy and point-group symmetry of the monomers.

F-18 Labelling Synthesis, Radioanalysis and Evaluation of A Dopamine Transporter and A Hypoxia Tracer

Positron emission tomography (PET) is an imaging technique in which radioactive positron-emitting tracers are used to study biochemical and physiological functions in humans and in animal experiments. The use of PET imaging has increased rapidly in recent years, as have special requirements in the fields of neurology and oncology for the development of syntheses for new, more specific and selective radiotracers. Synthesis development and automation are necessary when high amounts of radioactivity are needed for multiple PET studies. In addition, preclinical studies using experimental animal models are necessary for evaluating the suitability of new PET tracers for humans. For purification and analysing the labelled end-product, an effective radioanalytical method combined with an optimal radioactivity detection technique is of great importance. In this study, a fluorine-18 labelling synthesis method for two tracers was developed and optimized, and the usefulness of these tracers for possible prospective human studies was evaluated. N-(3-[18F]fluoropropyl)-2β-carbomethoxy-3β-(4-fluorophenyl)nortropane ([18F]β-CFT-FP) is a candidate PET tracer for the dopamine transporter (DAT), and 1H-1-(3-[18F]fluoro-2-hydroxypropyl)-2-nitroimidazole ([18F]FMISO) is a well-known hypoxia marker for hypoxic but viable cells in tumours. The methodological aim of this thesis was to evaluate the status of thin-layer chromatography (TLC) combined with proper radioactivity detection measurement systems as a radioanalytical method. Three different detection methods of radioactivity were compared: radioactivity scanning, film autoradiography, and digital photostimulated luminescence (PSL) autoradiography. The fluorine-18 labelling synthesis for [18F]β-CFT-FP was developed and carbon-11 labelled [11C]β-CFT-FP was used to study the specificity of β-CFT-FP for the DAT sites in human post-mortem brain slices. These in vitro studies showed that β-CFT-FP binds to the caudate-putamen, an area rich of DAT. The synthesis of fluorine-18 labelled [18F]FMISO was optimized, and the tracer was prepared using an automated system with good and reproducible yields. In preclinical studies, the action of the radiation sensitizer estramustine phosphate on the radiation treatment and uptake of [18F]FMISO was evaluated, with results of great importance for later human studies. The methodological part of this thesis showed that radioTLC is the method of choice when combined with an appropriate radioactivity detection technique. Digital PSL autoradiography proved to be the most appropriate when compared to the radioactivity scanning and film autoradiography methods. The very high sensitivity, good resolution, and wide dynamic range of digital PSL autoradiography are its advantages in detection of β-emitting radiolabelled substances.

Computational Studies on Bimetallic Clusters

The chemical and physical properties of bimetallic clusters have attracted considerable attention due to the potential technological applications of mixed-metal systems. It is of fundamental interests to study clusters because they are the link between atomic surface and bulk properties. More information of metal-metal bond in small clusters can be hence released. The studies in my thesis mainly focus on the two different kinds of bimetallic clusters: the clusters consisting of extraordinary shaped all metal four-membered rings and a series of sodium auride clusters. As described in most general organic chemistry books nowadays, a group of compounds are classified as aromatic compounds because of their remarkable stabilities, particular geometrical and energetic properties and so on. The notation of aromaticity is essentially qualitative. More recently, the connection has been made between aromaticity and energetic and magnetic properties. Also, the discussions of the aromatic nature of molecular rings are no longer limited to organic compounds obeying the Hückel’s rule. In our research, we mainly applied the GIMIC method to several bimetallic clusters at the CCSD level, and compared the results with those obtained by using chemical shift based methods. The magnetically induced ring currents can be generated easily by employing GIMIC method, and the nature of aromaticity for each system can be therefore clarified. We performed intensive quantum chemical calculations to explore the characters of the anionic sodium auride clusters and the corresponding neutral clusters since it has been fascinating in investigating molecules with gold atom involved due to its distinctive physical and chemical properties. As small gold clusters, the sodium auride clusters seem to form planar structures. With the addition of a negative charge, the gold atom in anionic clusters prefers to carry the charge and orients itself away from other gold atoms. As a result, the energetically lowest isomer for an anionic cluster is distinguished from the one for the corresponding neutral cluster. Mostly importantly, we presented a comprehensive strategy of ab initio applications to computationally implement the experimental photoelectron spectra.

Lake sediment research as a part of lake management - case studies and implications from southern Finland

In Finland one of the most important current issues in the environmental management is the quality of surface waters. The increasing social importance of lakes and water systems has generated wide-ranging interest in lake restoration and management, concerning especially lakes suffering from eutrophication, but also from other environmental impacts. Most of the factors deteriorating the water quality in Finnish lakes are connected to human activities. Especially since the 1940's, the intensified farming practices and conduction of sewage waters from scattered settlements, cottages and industry have affected the lakes, which simultaneously have developed in to recreational areas for a growing number of people. Therefore, this study was focused on small lakes, which are human impacted, located close to settlement areas and have a significant value for local population. The aim of this thesis was to obtain information from lake sediment records for on-going lake restoration activities and to prove that a well planned, properly focused lake sediment study is an essential part of the work related to evaluation, target consideration and restoration of Finnish lakes. Altogether 11 lakes were studied. The study of Lake Kaljasjärvi was related to the gradual eutrophication of the lake. In lakes Ormajärvi, Suolijärvi, Lehee, Pyhäjärvi and Iso-Roine the main focus was on sediment mapping, as well as on the long term changes of the sedimentation, which were compared to Lake Pääjärvi. In Lake Hormajärvi the role of different kind of sedimentation environments in the eutrophication development of the lake's two basins were compared. Lake Orijärvi has not been eutrophied, but the ore exploitation and related acid main drainage from the catchment area have influenced the lake drastically and the changes caused by metal load were investigated. The twin lakes Etujärvi and Takajärvi are slightly eutrophied, but also suffer problems associated with the erosion of the substantial peat accumulations covering the fringe areas of the lakes. These peat accumulations are related to Holocene water level changes, which were investigated. The methods used were chosen case-specifically for each lake. In general, acoustic soundings of the lakes, detailed description of the nature of the sediment and determinations of the physical properties of the sediment, such as water content, loss on ignition and magnetic susceptibility were used, as was grain size analysis. A wide set of chemical analyses was also used. Diatom and chrysophycean cyst analyses were applied, and the diatom inferred total phosphorus content was reconstructed. The results of these studies prove, that the ideal lake sediment study, as a part of a lake management project, should be two-phased. In the first phase, thoroughgoing mapping of sedimentation patterns should be carried out by soundings and adequate corings. The actual sampling, based on the preliminary results, must include at least one long core from the main sedimentation basin for the determining the natural background state of the lake. The recent, artificially impacted development of the lake can then be determined by short-core and surface sediment studies. The sampling must be focused on the basis of the sediment mapping again, and it should represent all different sedimentation environments and bottom dynamic zones, considering the inlets and outlets, as well as the effects of possible point loaders of the lake. In practice, the budget of the lake management projects of is usually limited and only the most essential work and analyses can be carried out. The set of chemical and biological analyses and dating methods must therefore been thoroughly considered and adapted to the specific management problem. The results show also, that information obtained from a properly performed sediment study enhances the planning of the restoration, makes possible to define the target of the remediation activities and improves the cost-efficiency of the project.

Microeconometric Studies on Unemployment and Business Cycles

Väitöskirja koostuu neljästä esseestä, joissa tutkitaan empiirisen työntaloustieteen kysymyksiä. Ensimmäinen essee tarkastelee työttömyysturvan tason vaikutusta työllistymiseen Suomessa. Vuonna 2003 ansiosidonnaista työttömyysturvaa korotettiin työntekijöille, joilla on pitkä työhistoria. Korotus oli keskimäärin 15 % ja se koski ensimmäistä 150 työttömyyspäivää. Tutkimuksessa arvioidaan korotuksen vaikutus vertailemalla työllistymisen todennäköisyyksiä korotuksen saaneen ryhmän ja vertailuryhmän välillä ennen uudistusta ja sen jälkeen. Tuloksien perusteella työttömyysturvan korotus laski työllistymisen todennäköisyyttä merkittävästi, keskimäärin noin 16 %. Korotuksen vaikutus on suurin työttömyyden alussa ja se katoaa kun oikeus korotettuun ansiosidonnaiseen päättyy. Toinen essee tutkii työttömyyden pitkän aikavälin kustannuksia Suomessa keskittyen vuosien 1991 – 1993 syvään lamaan. Laman aikana toimipaikkojen sulkeminen lisääntyi paljon ja työttömyysaste nousi yli 13 prosenttiyksikköä. Tutkimuksessa verrataan laman aikana toimipaikan sulkemisen vuoksi työttömäksi jääneitä parhaassa työiässä olevia miehiä työllisinä pysyneisiin. Työttömyyden vaikutusta tarkastellaan kuuden vuoden seurantajaksolla. Vuonna 1999 työttömyyttä laman aikana kokeneen ryhmän vuosiansiot olivat keskimäärin 25 % alemmat kuin vertailuryhmässä. Tulojen menetys johtui sekä alhaisemmasta työllisyydestä että palkkatasosta. Kolmannessa esseessä tarkastellaan Suomen 1990-luvun alun laman aiheuttamaa työttömyysongelmaa tutkimalla työttömyyden kestoon vaikuttavia tekijöitä yksilötasolla. Kiinnostuksen kohteena on työttömyyden rakenteen ja työn kysynnän muutoksien vaikutus keskimääräiseen kestoon. Usein oletetaan, että laman seurauksena työttömäksi jää keskimääräistä huonommin työllistyviä henkilöitä, jolloin se itsessään pidentäisi keskimääräistä työttömyyden kestoa. Tuloksien perusteella makrotason kysyntävaikutus oli keskeinen työttömyyden keston kannalta ja rakenteen muutoksilla oli vain pieni kestoa lisäävä vaikutus laman aikana. Viimeisessä esseessä tutkitaan suhdannevaihtelun vaikutusta työpaikkaonnettomuuksien esiintymiseen. Tutkimuksessa käytetään ruotsalaista yksilötason sairaalahoitoaineistoa, joka on yhdistetty populaatiotietokantaan. Aineiston avulla voidaan tutkia vaihtoehtoisia selityksiä onnettomuuksien lisääntymiselle noususuhdanteessa, minkä on esitetty johtuvan esim. stressin tai kiireen vaikutuksesta. Tuloksien perusteella työpaikkaonnettomuudet ovat syklisiä, mutta vain tiettyjen ryhmien kohdalla. Työvoiman rakenteen vaihtelu saattaa selittää osan naisten onnettomuuksien syklisyydestä. Miesten kohdalla vain vähemmän vakavat onnettomuudet ovat syklisiä, mikä saattaa johtua strategisesta käyttäytymisestä.

Phylogenetic studies of cyanobacterial lichens

Phylogenetic studies of cyanobacterial lichens Lichens are symbiotic assemblages between fungi (mycobiont) and green algae (phycobiont) or/and cyanobacteria (cyanobiont). Fossil records show that lichen-like symbioses occurred already 600 million years ago. Lichen symbiosis has since then become an important life strategy for the Fungi, particularly for species in the phylum Ascomycota as approximately 98% of the lichenized fungal species are ascomycetes. The taxonomy of lichen associations is based on the mycobiont. We reconstructed, using DNA sequence data, hypotheses of phylogenetic relationships of lichen-forming fungi that include species associated with cyanobacteria. These hypotheses of phylogeny should form the basis for the taxonomy. They also allowed studies of the origin and the evolution of specific symbioses. Genetic diversity and phylogenetic relationships of symbiotic cyanobionts were also studied in order to examine selectivity of cyanobionts and mycobionts as well as possible co-evolution between partners involved in lichen associations. The suggested circumscription of the family Stereocaulaceae to include Stereocaulon and Lepraria is supported. The recently described crustose Stereocaulon species seem to be correctly placed in the genus, although Stereocaulon traditionally included only fruticose species. The monospecific crustose genus Muhria is also shown to be best placed in Stereocaulon. Family Lobariaceae as currently delimited is monophyletic. Within Lobariaceae genus Sticta including Dendriscocaulon dendroides form a monophyletic group while the genera Lobaria and Pseudocyphellaria are non-monophyletic. A new classification of Lobariaceae is obviously needed. Further studies are however required before a final proposal for a new classification can be made. Our results show that the cyanobacterial symbiotic state has been gained repeatedly in the Ascomycota while losses of symbiotic cyanobacteria appear to be rare. The symbiosis with green algae is confirmed to have been gained repeatedly in Ascomycota but also repeatedly lost. Cyanobacterial symbioses therefore seem to be more stable than green algal associations. Cyanobacteria are perhaps more beneficial for the lichen fungi and therefore maintained. The results indicate a dynamic association of the lichen symbiosis. This evolutionary instability will perhaps be important for the lichen fungi as the utilization of options will perhaps enable lichens to colonize new substrates and survive environmental changes. Some cyanobacterial lichen genera seem to be highly selective towards the cyanobiont while others form symbioses with a broad spectrum of cyanobacteria. No evidence of co-evolution between fungi and cyanobacteria in cyanolichens could be demonstrated.

The visual preferences for forest regeneration and field afforestation - four case studies in Finland

The overall aim of this dissertation was to study the public's preferences for forest regeneration fellings and field afforestations, as well as to find out the relations of these preferences to landscape management instructions, to ecological healthiness, and to the contemporary theories for predicting landscape preferences. This dissertation includes four case studies in Finland, each based on the visualization of management options and surveys. Guidelines for improving the visual quality of forest regeneration and field afforestation are given based on the case studies. The results show that forest regeneration can be connected to positive images and memories when the regeneration area is small and some time has passed since the felling. Preferences may not depend only on the management alternative itself but also on the viewing distance, viewing point, and the scene in which the management options are implemented. The current Finnish forest landscape management guidelines as well as the ecological healthiness of the studied options are to a large extent compatible with the public's preferences. However, there are some discrepancies. For example, the landscape management instructions as well as ecological hypotheses suggest that the retention trees need to be left in groups, whereas people usually prefer individually located retention trees to those trees in groups. Information and psycho-evolutionary theories provide some possible explanations for people's preferences for forest regeneration and field afforestation, but the results cannot be consistently explained by these theories. The preferences of the different stakeholder groups were very similar. However, the preference ratings of the groups that make their living from forest - forest owners and forest professionals - slightly differed from those of the others. These results provide support for the assumptions that preferences are largely consistent at least within one nation, but that knowledge and a reference group may also influence preferences.

Phylogeny of a taxonomically difficult group and evolution of host location mechanism

The parasitic wasps are one of the largest insect groups and their life histories are remarkably variable. Common to all parasitic wasps is that they kill their hosts, which are usually beetles, butterflies and sometimes spiders. Hosts are often at a larval or pupal stage and live in concealed conditions, such as in plant tissue. Parasitic wasps have two main ways of finding their host. 1) They can detect chemical compounds emitted by damaged plant material or released by larvae living in plant tissue, and 2) detect the larvae by sound vibrations. Even though pupae are immobile and silent, and therefore do not cause vibration, parasitoids have, however, adapted to find passive developmental stages by producing vibration themselves by knocking the substrate with their antennae, and then detecting the echoes with their legs. This echolocation allows a parasitoid to locate its potential hosts that are deeply buried in wood. This study focuses on the relationships of the subfamily Cryptinae (Hymenoptera: Ichneumonidae) and related taxa, and the evolution of host location mechanism. There are no earlier studies of the phylogeny of the Cryptinae, and the position of related taxa are unclear. According to the earlier classification, which is entirely intuitional, the Cryptinae is divided into three tribes: Cryptini, Hemigasterini and Phygadeuontini. Further, these tribes are subdiveded into numerous subtribes. This work, based on molecular characters, shows that the cryptine tribes Cryptini, Phygadeuon¬tini and Hemigasterini come out largely as monophyletic groups, thus agreeing with the earlier classification. The earlier subtribal classification had no support. In addition, it is shown that modified antennal structures are associated with host usage of wood-boring coleopteran hosts. The cryptines have a clear modification series on their antennal tips from a simply tip to a hammer-like structure. The species with strongly modified antennae belong mostly to the tribe Cryptini and they utilise wood-boring beetles as hosts. Also, field observations on insect behaviour support this result.

Evaluation of regional and distant metastases in head and neck squamous cell carcinoma patients with special reference to the assessment of regional lymph nodes in oral cancer

For optimal treatment planning, a thorough assessment of the metastatic status of mucosal squamous cell carcinoma of the head and neck (HNSCC) is required. Current imaging methods do not allow the recognition of all patients with metastatic disease. Therefore, elective treatment of the cervical lymph nodes is usually given to patients in whom the risk of subclinical metastasis is estimated to exceed 15-20%. The objective of this study was to improve the pre-treatment evaluation of patients diagnosed with HNSCC. Particularly, we aimed at improving the identification of patients who will benefit from elective neck treatment. Computed tomography (CT) of the chest and abdomen was performed prospectively for 100 patients diagnosed with HNSCC. The findings were analysed to clarify the indications for this examination in this patient group. CT of the chest influenced the treatment approach in 3% of patients, while CT of the abdomen did not reveal any significant findings. Our results suggest that CT of the chest and abdomen is not indicated routinely for patients with newly diagnosed HNSCC but can be considered in selected cases. Retrospective analysis of 80 patients treated for early stage squamous cell carcinoma of the oral tongue was performed to investigate the potential benefits of elective neck treatment and to examine whether histopathological features of the primary tumour could be used in the prediction of occult metastases, local recurrence, or/and poor survival. Patients who had received elective neck treatment had significantly fewer cervical recurrences during the follow-up when compared to those who only had close observation of the cervical lymph nodes. Elective neck treatment did not result in survival benefit, however. Of the histopathological parameters examined, depth of infiltration and pT-category (representing tumour diameter) predicted occult cervical metastasis, but only the pT-category predicted local recurrence. Depth of infiltration can be used in the identification of at risk patients but no clear cut-off value separating high-risk and low-risk patients was found. None of the histopathological parameters examined predicted survival. Sentinel lymph node (SLN) biopsy was studied as a means of diagnosing patients with subclinical cervical metastases. SLN biopsy was applied to 46 patients who underwent elective neck dissection for oral squamous cell carcinoma. In addition, SLN biopsy was applied to 13 patients with small oral cavity tumours who were not intended to undergo elective neck dissection because of low risk of occult metastasis. The sensitivity of SLN biopsy for finding subclinical cervical metastases was found to be 67%, when SLN status was compared to the metastatic status of the rest of the neck dissection specimen. Of the patients not planned to have elective neck dissection, SLN biopsy revealed cervical metastasis in 15% of the patients. Our results suggest that SLN biopsy can not yet entirely replace elective neck dissection in the treatment of oral cancer, but it seems beneficial for patients with low risk of metastasis who are not intended for elective neck treatment according to current treatment protocols.

Placental abruption : Studies on incidence, risk factors and potential predictive biomarkers

Placental abruption, one of the most significant causes of perinatal mortality and maternal morbidity, occurs in 0.5-1% of pregnancies. Its etiology is unknown, but defective trophoblastic invasion of the spiral arteries and consequent poor vascularization may play a role. The aim of this study was to define the prepregnancy risk factors of placental abruption, to define the risk factors during the index pregnancy, and to describe the clinical presentation of placental abruption. We also wanted to find a biochemical marker for predicting placental abruption early in pregnancy. Among women delivering at the University Hospital of Helsinki in 1997-2001 (n=46,742), 198 women with placental abruption and 396 control women were identified. The overall incidence of placental abruption was 0.42%. The prepregnancy risk factors were smoking (OR 1.7; 95% CI 1.1, 2.7), uterine malformation (OR 8.1; 1.7, 40), previous cesarean section (OR 1.7; 1.1, 2.8), and history of placental abruption (OR 4.5; 1.1, 18). The risk factors during the index pregnancy were maternal (adjusted OR 1.8; 95% CI 1.1, 2.9) and paternal smoking (2.2; 1.3, 3.6), use of alcohol (2.2; 1.1, 4.4), placenta previa (5.7; 1.4, 23.1), preeclampsia (2.7; 1.3, 5.6) and chorioamnionitis (3.3; 1.0, 10.0). Vaginal bleeding (70%), abdominal pain (51%), bloody amniotic fluid (50%) and fetal heart rate abnormalities (69%) were the most common clinical manifestations of placental abruption. Retroplacental blood clot was seen by ultrasound in 15% of the cases. Neither bleeding nor pain was present in 19% of the cases. Overall, 59% went into preterm labor (OR 12.9; 95% CI 8.3, 19.8), and 91% were delivered by cesarean section (34.7; 20.0, 60.1). Of the newborns, 25% were growth restricted. The perinatal mortality rate was 9.2% (OR 10.1; 95% CI 3.4, 30.1). We then tested selected biochemical markers for prediction of placental abruption. The median of the maternal serum alpha-fetoprotein (MSAFP) multiples of median (MoM) (1.21) was significantly higher in the abruption group (n=57) than in the control group (n=108) (1.07) (p=0.004) at 15-16 gestational weeks. In multivariate analysis, elevated MSAFP remained as an independent risk factor for placental abruption, adjusting for parity ≥ 3, smoking, previous placental abruption, preeclampsia, bleeding in II or III trimester, and placenta previa. MSAFP ≥ 1.5 MoM had a sensitivity of 29% and a false positive rate of 10%. The levels of the maternal serum free beta human chorionic gonadotrophin MoM did not differ between the cases and the controls. None of the angiogenic factors (soluble endoglin, soluble fms-like tyrosine kinase 1, or placental growth factor) showed any difference between the cases (n=42) and the controls (n=50) in the second trimester. The levels of C-reactive protein (CRP) showed no difference between the cases (n=181) and the controls (n=261) (median 2.35 mg/l [interquartile range {IQR} 1.09-5.93] versus 2.28 mg/l [IQR 0.92-5.01], not significant) when tested in the first trimester (mean 10.4 gestational weeks). Chlamydia pneumoniae specific immunoglobulin G (IgG) and immunoglobulin A (IgA) as well as C. trachomatis specific IgG, IgA and chlamydial heat-shock protein 60 antibody rates were similar between the groups. In conclusion, although univariate analysis identified many prepregnancy risk factors for placental abruption, only smoking, uterine malformation, previous cesarean section and history of placental abruption remained significant by multivariate analysis. During the index pregnancy maternal alcohol consumption and smoking and smoking by the partner turned out to be the major independent risk factors for placental abruption. Smoking by both partners multiplied the risk. The liberal use of ultrasound examination contributed little to the management of women with placental abruption. Although second-trimester MSAFP levels were higher in women with subsequent placental abruption, clinical usefulness of this test is limited due to low sensitivity and high false positive rate. Similarly, angiogenic factors in early second trimester, or CRP levels, or chlamydial antibodies in the first trimester failed to predict placental abruption.