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  • Kallionpää, Roope (2014)
    Estrogens are female sex hormones that have genotoxic and proliferation-enhancing effects in cells. Life-time exposure to estrogens is linked to the risk of several cancers. Estrone is only a weak agonist of estrogen receptor but it serves as a precursor for biosynthesis of 17β-estradiol, 16α-hydroxyestrone and catechol estrogens. While 16α-hydroxyestrone has relatively weak affinity for estrogen receptor, it has prolonged effect due to covalent binding to the receptor. UDP-glucuronosyltransferases (UGTs) are phase II metabolic enzymes that conjugate estrogens with glucuronic acid to render them more watersoluble. Polymorphisms in UGT genes have been linked to excretion of steroids and risk of some cancers. Generally, subfamily UGT1A enzymes conjugate the 3-hydroxyls of estrogens, while the activity of subfamily UGT2B is directed towards 16- and 17-hydroxyls. Previous results on estrone glucuronidation are incomplete and conflicting, while glucuronidation of 16α-hydroxyestrone has not been systematically studied. The aim of this study was to identify UGTs active in the glucuronidation of estrone and 16α-hydroxyestrone and to further examine the glucuronidation kinetics of the active UGTs. Also the effects of bovine serum albumin (BSA), dimethyl sulfoxide (DMSO) and mutations of UGT1A10F90 and UGT1A10F93 on glucuronidation activity were examined. Activity assays were conducted using recombinant enzymes as well as human liver and intestinal microsomes. Resulting glucuronides were analyzed using high performance liquid chromatography and quantified based on their UV absorbance. UGT1A3, UGT1A10 and UGT2A1 showed the highest activity toward estrone glucuronidation, while UGT1A10, UGT2A1 and UGT2B7 were the most efficient UGTs conjugating 16α-hydroxyestrone. UGT1A10 had the highest Vmax in the glucuronidation of both substrates, although it conjugated estrone at a higher rate than 16α-hydroxyestrone. UGT1A10F93 was shown to have a role in the different glucuronidation activities of UGT1A10 toward estrone and 16α-hydroxyestrone. Affinity of 16α-hydroxyestrone was highest for UGT2B7, while UGT2B17 conjugated 16α-hydroxyestrone relatively slowly. The results confirm earlier observations of the preference of UGT2B7 for α-configured hydroxyls while UGT2B17 favors β-configuration. UGT2A1 showed no strict regioselectivity but had a relatively weak affinity for both substrates. DMSO was found to decrease UGT activity. However, its presence is necessary to solubilize lipophilic substrates. DMSO concentration has to be kept constant to produce comparable data for, for example, kinetic studies. BSA was found to alter especially the kinetics of UGT2A1. BSA also seemed to have solubility-enhancing effect.
  • Haikonen, Joni (2019)
    Kainate receptors are known to regulate neuronal function in the brain (Li, H., & Rogawski, M. A. (1998), Braga, M. F. et al. (2004), Lerma & Marques (2013), Carta, M (2014)). In the amygdala, they have been shown to affect synaptic transmission and plasticity, as well as glutamate and γ-aminobutyric acid (GABA) release (Li, H. et al. (2001). Braga, M. F. et al. (2003), Braga, M. F. et al. (2009), Aroniadou-Anderjaska, V. et al. (2012), Negrete‐Díaz, J. V. et al. (2012)), however, their role during development of the amygdala circuitry is not known. In the present study, we wished to understand how GluK1 kainate receptors regulate synaptic population activity and plasticity in the developing amygdala by using extracellular field recordings in P15-18 Wistar Han rat pup brain slices. Since field excitatory postsynaptic potentials (fEPSPs) are not commonly measured from the amygdala, we first sought to pharmacologically characterize the basic properties of the extracellular signal, recorded from the basolateral amygdala in response to stimulation of the external capsulae (EC). Having confirmed the validity of the fEPSP as a measure of postsynaptic population response, we were able to show that blocking GluK1 with (S)-1-(2-Amino-2-carboxyethyl)-3-(2-carboxy-5-phenylthiophene-3-yl-methyl)-5-methylpyrimidine-2,4-dione (ACET), a selective GluK1 antagonist, had no effect on the fEPSP. Furthermore, activation of GluK1 with RS-2-amino-3-(3-hydroxy-5-tert-butylisoxazol-4-yl) propanoic acid (ATPA), a GluK1 agonist, reduced the amplitude of the fEPSP, without affecting its slope, suggesting an increase in inhibitory signaling within the network. Blocking GABAergic activity with GABAA- receptor antagonist picrotoxin significantly reduced the effects of ATPA. Additionally, the increase in inhibitory signaling due to the activation of GluK1 was confirmed with whole-cell voltage clamp, by measuring spontaneous inhibitory postsynaptic current (sIPSC) frequency. Activation of GluK1 heavily increased sIPSC frequency in the basolateral amygdala neurons. Finally, we were also able to show that activation of GluK1 with ATPA strongly attenuates LTP induction. These results show that GluK1 kainate receptors play a vital role in the modulation of synaptic transmission and plasticity in the developing amygdala.
  • Mattila, Ninni (2015)
    Glukokortikoidit ovat steroidihormoneja, jotka säätelevät laajalti elimistön monia fysiologisia tapahtumia. Ne ovat keskeisiä myös tulehduksien ja autoimmuunisairauksien lääkehoidossa. Lisämunuaisia on perinteisesti pidetty elimistön ainoana glukokortikoidien tuottajana, mutta viimeaikaiset tutkimukset osoittavat niiden synteesiä tapahtuvan myös paikallisesti mm. ruuansulatuskanavassa – eniten ohutsuolessa – sekä kateenkorvassa, ihossa, keuhkoissa, verisuonissa ja keskushermostossa. Suoliston glukokortikoidituoton säätely eroaa merkittävästi lisämunuaisissa tapahtuvasta. Suoliston tuottamat glukokortikoidit säätelevät paikallista immuunipuolustusta ja tulehdusreaktiota, millä saattaa olla yhteys tulehduksellisten suolistosairauksien, kuten Crohnin taudin ja haavaisen paksusuolentulehduksen, patologisiin mekanismeihin. Glukokortikoidit saattavat vaikuttaa myös paksusuolen syövän kehitykseen. Tutkimusryhmämme selvitti koe-eläimillä (hiiri) kortikosteronituottoa ruuansulatuskanavan eri osissa jatkotutkimuksia varten.
  • Teperi, Kaisa (2020)
    Raskausdiabetes yleistyy niin Suomessa kuin muuallakin maailmassa. Vuonna 2018 raskausdiabetes todettiin 21 %:lla suomalaisista synnyttäjistä. Hoitamattomana raskausdiabetes vaikuttaa sekä odottavan äidin että syntyvän lapsen terveyteen. Raskausdiabeteksen diagnoosi perustuu kahden tunnin glukoosirasituskokeeseen, joka tehdään melkein kaikille ensisynnyttäjille sekä niille uudelleensynnyttäjille, joilla on jokin raskausdiabeteksen riskitekijä. Kokeessa tutkittavan plasman glukoosipitoisuus mitataan ensin paastotilassa ja sitten tunnin ja kahden tunnin kuluttua glukoosijuoman nauttimisesta. Mikäli yksikin näistä mitatuista glukoosiarvoista ylittää käytössä olevan raja-arvon, tutkittavalla todetaan raskausdiabetes. Tämän tutkimuksen tarkoituksena on selvittää, eroavatko glukoosirasituskokeen tulokset toisistaan samojen naisten ensimmäisessä ja toisessa raskaudessa. Tutkimusaineisto koostuu niistä suomen- tai ruotsinkielisistä vantaalaisista naisista, joilla oli ensimmäinen ja toinen synnytys tutkimusajanjaksolla 1.1.2009-31.12.2015, joiden molemmat raskaudet olivat yksisikiöisiä ja joille tehtiin molemmissa raskauksissa glukoosirasituskoe (N=890). Tutkittavien tiedot saatiin Terveyden ja hyvinvoinnin laitoksen syntymärekisteristä, Tilastokeskuksesta sekä Vantaan terveyskeskuksen potilasrekisteristä. Ensimmäisessä raskaudessa tutkittavien paastoglukoosiarvo oli keskimäärin 0,2 mmol/l matalampi kuin toisessa raskaudessa. Ero säilyi merkitsevänä, kun paastoglukoosiarvon muutos vakioitiin äidin iän, koulutustaustan, siviilisäädyn, raskauksien välisen ajan ja äidin painoindeksin muutoksen suhteen. Eniten muutosta selitti painoindeksin kasvu. Myös äidin iällä ja raskauksien välisellä ajalla oli itsenäinen vaikutus paastoglukoosiarvon kasvuun. Glukoosirasituksen yhden ja kahden tunnin glukoosiarvoissa ei todettu merkitsevää eroa raskauksien välillä. Raskausdiabetes todettiin ensimmäisessä raskaudessa 25 %:lla ja toisessa raskaudessa 35 %:lla tutkittavista.
  • Mattila, Susanna (2012)
    The aim of the stydy was to evaluate how different chemical derivatization methods are suitable for characterization of regional isomers of different glucuronide conjugates. Glucuronidation is one of the phase II metabolic reactions where more water soluble and often inactive substances are produced. Different functional groups may be subjected to glucuronidation. It is important to determine the exact position of glucuronidation, as the isomers may possess different toxicological or pharmacological properties. For example morphine-6-glucuronide is pharmacologically more active than morphine itself. The glucuronide conjugates are commonly detected by liquid chromatography tandem mass spectrometry (LC-MS/MS) and/or nuclear magnetic resonance (NMR). MS/MSspectra of native molecule and glucuronidated molecule are usually similar because of an initial loss of 176 Da, i.e. monodehydrated glucuronic acid. This fact often makes it impossible to determine the site of glucuronidation. Samples of NMR-analysis requires larger amounts of sample materials than MS-analysis. Many of those derivatization reagents tested in this study were not reacting as they were supposed to react according to literature. O-phthalaldehyde (OPA) and 9-fluorenylmethyl chloroformate (FMOC) were forming derivatives as expected and those reagents are very suitable for glucuronide conjugates studies. At the end of the studies the site of the glucuronidation of dopamine- and serotonineglucuronides were evaluated by derivatization with OPA and FMOC. Derivatization with OPA and FMOC successfully gave information about the region of the glucuronide acid in dopamine- and serotoninemolecules. The assumptions supposed to be correct according to NMR-studies presented in literature.
  • Junttila, Emmi (2018)
    Many food products such as butter, salad dressings and ice-cream consist of water-in-oil (W/O) or oil-in-water (O/W) emulsions. Emulsions are thermodynamically unstable and this is the reason why food industry uses different kinds of emulsifiers and stabilizers which extend the shelf-life of the products and also improves their quality. The consumers’ interest towards plan-based and sustainable ingredients has increased, but at the moment the number of Finnish plant-based stabilizers is limited. Forest industry is also under pressure to find new use for its by-products.. Some studies on the glucuronoxylan and galactoglucomannan extracted from spruce and birch saw meal have been made and the results have been promising. Xylan has been extracted by different methods and from birch sawdust the yield has been approximately 50 wt%. The use of birch GX in food products has not yet been authorized, but the food industry is already using some of the byproducts of woodworking industry such as xylitol. The aim of this study was to find the suitable mixture ratio of oil, water and birch glucuronoxylan in emulsions as well as the factors affecting the physical state of the emulsions. The results of this study can be used to support the findings of other studies so that domestic plant based emulsion stabilizers can be used in the food-industry in the future. In this study seven different emulsions were produced by varying the ratio of oil and glucuronoxylan. By studying the physical properties of the freshly prepared emulsions together with the varying storage conditions (+4 °C, +21 °C and +40 °C) the study aimed to find the optimal mixture ratio. The droplet size of dispersed phase was studied by using static light scattering and the possible flocculation was viewed by optical microscopy. The height of the creamed phase and the turbidity/ other changes in appearance were visually investigated by photographing the samples. A sample of emulsion was taken apart and centrifuged to find out the amount of xylan on the oil droplet interface and in the continuous phase. In addition, the monosaccharide composition of xylan on oil droplet interface and continuous phase were determined by gas chromatography mass spectrometry (GC-MS). All the seven emulsions investigated were polydispersions according to the droplet size distribution. There were two peaks on almost every droplet size distributions since the first measuring. The droplet size distributions were stable for the whole 67 days investigation period when the emulsions were stored in +4 °C temperature excluding two emulsions. In +21 °C and +40 °C temperatures the droplet size of all the investigated emulsion grew. The greatest part of the carbohydrates was in the continuous phase of emulsions. The size difference between the polysaccharides from the surface of the oil droplets and the continuous phase was not big. About 80 % of the monosaccharides in the emulsions was xylose. According to the findings of this study, there was more methyl glucuronic acid, which is a component of xylan, in the water than in the interfacial oil phase of the emulsions (0.65 – 5.7 μg/g).
  • Seppä, Venla (2022)
    Depressio on vakava mielenterveyden häiriö, josta kärsii arviolta viisi prosenttia maailman aikuisväestöstä. Nykyiset, yleisesti käytetyt antidepressantit ovat hyödyllisiä työkaluja depressiivisten oireyhtymien hoidossa, mutta ne tehoavat vain noin kahteen kolmannekseen potilaista. Lisäksi niiden annostelun ja terapeuttisen vasteen välinen, jopa viikkojen mittainen viive tekee niistä hyödyttömiä akuuttien masennusoireiden hoidossa. Viime vuosina aivojen glutamaattia välittäjäaineenaan käyttävän signalointijärjestelmän metabotrooppisia reseptoreita eli mGlu-reseptoreita on tutkittu mahdollisena uusien antidepressanttien vaikutuskohtana. Useat koe-eläimillä suoritetut tutkimukset ovat antaneet viitteitä siitä, että tyyppien 2 ja 3 mGlu-reseptorien antagonismi voisi tuottaa nopean ja tehokkaan antidepressiivisen vasteen ilman merkittäviä haittavaikutuksia, joita samoin vaikuttava, tehokkaaksi mutta verrattain toksiseksi antidepressantiksi todettu ketamiini aiheuttaa. Näin ollen mGlu2/3-reseptorien antagonistit voisivat olla merkittävä edistysaskel uusien, entistä tehokkaampien depression hoitokeinojen kehittelyssä. Tällä tutkimuksella pyrittiin selvittämään mGlu2/3-reseptorien LY341495-antagonistin pitkäaikaisvaikutuksia hiirten stressireaktioihin. Tutkimuksessa hyödynnettiin yleisesti koe-eläinten masennusmallina käytettävää pakotettua uintitestiä (forced swim test) sekä immunohistokemiallisia värjäyksiä, joiden avulla LY341495:n antidepressiivisiä vaikutuksia arvioitiin vuorokausi sen annostelun jälkeen. Tuloksissa antagonistilla ei havaittu tilastollisesti merkittävää vaikutusta hiirten kokeman stressireaktion voimakkuuteen. Aiempien, päinvastaisia tuloksia antaneiden tutkimusten valossa lisätutkimuksia kuitenkin tarvitaan, ennen kuin antagonistin mahdollisuutta antidepressanttina voidaan poissulkea kokonaan.
  • Viitanen, Arto I. (2019)
    The intestinal stem cells (ISC) are responsible for the regeneration of the intestine epithelial barrier after acute injury and for the replenishment of its cells overall. How the ISC activation and resulting proliferation is controlled is complex and still under study. The ISCs of the midgut, which is the functional analogue to mammalian small intestine, are also highly responsive to changes in nutrition, and with proper methodologies it is possible to study the effects of diet on stem cell activation. The metabolic flux of the nutritional components of the diet can then shed light on which metabolic pathways are necessary for nutrient-dependent proliferation. One nutrient that has garnered interest is glutamine (Gln). It is well established that glutamine supplementation can in parenterally fed patients diminish intestinal barrier atrophy, extend the time the patient can be kept under the regime, and increase survivability of critically ill patients. Consequently, glutamine or its downstream metabolites may have stem cell activating characteristics. However, the exact regulatory mechanisms and specific effects of Gln are not well known, and studies have found contradictory results on the beneficial effects of Gln supplementation. Glutamine itself is a conditionally essential amino acid that has a variety of functions: it is an important source of nitrogen and cellular energy and contributes carbon into the tricarboxylic acid cycle (TCA) and is involved in protein and nucleotide synthesis. In this thesis, the effects of Gln supplementation on the cell populations of D. melanogaster were studied via microscopy and computational analysis. Cross-breeds of fruit fly were established to lineage label the ISC with a GAL4/UAS driver system. Confocal microscope was used to image the midguts which were then analysed with Imaris software. A novel analysis method was developed to study population changes and varying features of the cells in the midgut in an unprecedented region-by-region bulk analysis. Earlier studies into nutrient control of ISC have had limited focus within the midgut and might have consequently given a restricted view of ISC activation. This new Longitudinal Analysis of Midgut (LAM) can be utilized in a diverse set of further studies to describe conditional variation within midgut, and possibly other tissues. Gln was found to increase total cell numbers to comparable levels with well-fed midguts, and to drive limited endoreplication in enterocytes. Lineage labelled cell population grew primarily in the R3 and R4 regions of the midgut. Additionally, enteroendocrine cells (EE) were greatly increased in the posterior part of R3 but had conceivable minor increases along the whole length of the midgut. Improved nutrition was also found to affect the proportions of the midgut, presenting itself as elongated posterior and stunted anterior. Overall, the pipeline and analysis method established during this study enable more expeditious research of effects of other nutritional components and allows for study of effects of other mechanisms, for example how gene knock-downs or altered gene activities affect cell populations of the midgut.
  • Haapa, Anna Talvikki (2017)
    Following a gluten-free diet is continually more common. Previous research has shown that following a gluten-free diet significantly affects the everyday life and quality of life of an individual. The aim of the research was to find out how following a gluten-free diet affects the everyday control and quality of life of an individual. The aim was also to find out how motivational aspects are linked to the following of the diet. The research results were to be viewed from the point of view of self-determination theory and theory of planned behaviour. The research aims to collect information that will help to understand the factors that affect the everyday life control and quality of life of those following the gluten-free diet. The research was carried out as a quantitative cross-sectional study. The data collected through Helsinki university E-form was comprised of answers to 55 questions. The questionnaire was completed by 356 persons. The data were analysed using IBM SPSS -statistics 23 and AMOS Graphics 24. The data were analysed using independent samples t-test, 2 independents samples tests, Kruskal–Wallis test, One-Way ANOVA, Jonckheere–Terpstra test, Principal components' analysis and confirmatory factor analysis. Spearman and Pearson correlation coefficients were also calculated. The gluten free diet affected the every day functions and social situations in many ways. Those with coeliac disease found following the diet easier than those with other dietary restrictions. The easiness of following the diet lessened avoidant behaviour, stress during lunch and the occurrence of negative feelings. The feeling of adequate support from social environment affected positively the quality of life and everyday life control of the subjects, and the feeling of adequate support from the inner circle was connected with precise following of the diet. Motivational factors were connected to several coping strategies and factors affecting the quality of life. Precise following of the diet didn't necessarily ensue the knowledge of the significance of the diet. This intention-behaviour gap reflected the subjects' lack of motivation.
  • Sammalisto, Saara (2019)
    Gluteeniton kauraleivonta on teknologisesti haastavaa, sillä viskoelastisen gluteeniverkoston puuttuessa kaurataikinoita on hankalaa työstää ja kauraleivät jäävät usein tiiviiksi, kosteiksi ja tahmeiksi. Hyväksyttävän rakenteen aikaansaanti on vaikeaa ja gluteenittomille leiville on tyypillistä, että ne vanhenevat nopeasti. Leivän vanhenemiseen johtavina tekijöinä pidetään tärkkelyksen uudelleenkiteytymistä ja veden liikkumista leivässä säilytyksen aikana. Tutkimuksen tavoitteena oli parantaa gluteenittoman kauraleivän säilyvyyttä käyttämällä taikinassa esiliisteröityä tärkkelystä. Tutkimuksen hypoteesina oli, että velliksi esiliisteröidyn kaurajauhon käytöllä vesi saadaan sidottua tiukemmin tärkkelysgeeliin, jolloin säilytyksen aikana tapahtuva veden liikkuminen leivässä hidastuu. Kun rakennetta pehmentävä vesi puristuu hitaammin ulos tärkkelysgeelistä ja liisteröityneisiin, amorfisiin tärkkelysalueisiin on sitoutunut enemmän vettä, on leivän rakennetta kovettavien tärkkelyskiteiden muodostuminen hitaampaa. Lisäksi tutkimuksessa vertailtiin kauravellin hapatusta mikrobiologisella ja kemiallisella menetelmällä. Mikrobiologisen hapatuksen aikana jauhopartikkelit ehtivät vettyä ja liueta edelleen, ja tällä oletettiin olevan rakennetta pehmentävä vaikutus. Tutkimuksen kokeellisessa osassa kauraleipien rakenteen kovettumista tutkittiin kaksivaiheisella puristustestillä aineenkoestuslaitteella ja tärkkelyksen uudelleenkiteytymistä seurattiin DSC-kalorimetrillä. Taikinoiden ominaisuuksia havainnollistettiin erilaisin geelitestein. Tutkimuksessa havaittiin, että esiliisteröity kauravelli lisäsi kaurataikinan kaasunpidätyskykyä ja kasvatti kauraleivän ominaistilavuutta. Kemiallisesti hapatettua velliä sisältäneessä kauraleivässä rakenteen kovettuminen oli hitainta ja leipä oli tilastollisesti pehmein kuudenteen säilytyspäivään asti. Mikrobiologisesti hapatetun vellin käyttö taas nopeutti kauraleivän rakenteen vanhenemista. Esiliisteröidyn vellin käyttö pehmensi gluteenittoman kauraleivän rakennetta liisteröimällä enemmän tärkkelystä amorfiseen muotoon ja hidastamalla veden liikkumista leivässä säilytyksen aikana. Kauravellin kemiallinen hapatus pehmensi kauraleivän rakennetta edelleen, ja rakenne oli vellitöntä leipää pehmeämpi vielä kuudentena säilytyspäivänä. Tutkimuksessa onnistuttiin pidentämään gluteenittoman kauraleivän pehmeää aikaa käyttämällä taikinassa kemiallisesti hapatettua, esiliisteröityä velliä.
  • Tikkanen, Pinja (2021)
    Tutkimuksen tarkoituksena oli kartoittaa optimaalinen hydrokolloidiyhdistelmä, joka parantaa gluteenittoman leivän rakennetta ja tuoreena säilymistä. Hypoteesina oli, että löytyisi tietty kahden hydrokolloidin yhdistelmä koesuunnitelmaa käyttämällä. Tutkimuksessa käytettiin kolmea eri hydrokolloidia ja niiden määrät vaihtelivat kolmella eri tasolla. Hydrokolloidien vesiliuosten reologisia ominaisuuksia tutkittiin viskositeetti- ja oskillaatiomittauksilla. Leivistä mitattiin tilavuus, rakenne ja rakenteen säilyminen seitsemän vuorokauden säilytyksessä ja raskista mitattiin pH ja happoluku. Leivistä tehtiin myös aistinvarainen asiantuntija-arviointi. Raskien pH-arvojen keskiarvo oli 4,49 ±0,01 ja happoluvun keskiarvo 12,9 ±0,2. Hydrokolloidien vesiliuosseosten, GM + MNS1 ja GM + MNS2, viskositeettien mittauksissa virtauskäyrissä ei ollut eroa mutta GM:n (galaktomannaanista muodostunut kasvikumi, joka on peräisin palkokasvista) viskositeetti oli selvästi matalampi kuin seosten. Oskillaatiomittauksessa GM:n huomattiin myös erottuvan seoksista huomattavan paljon pienemmällä viskositeetilla sekä varasto- ja häviömoduulilla. GM muodostaa yksin ollessaan heikon geelirakenteen, mutta seoksilla on vahvempi geelirakenne. Modde-ohjelmiston vastepintaohjelman avulla saaduista tuloksista voitiin nähdä vain kimmoisuuden ja joustavuuden mallintuvan yhden päivän säilytyksen jälkeen. Tehtyjen analyysien perusteella päivä leivonnan jälkeen modifioitu neutraali selluloosa 1 (MNS1) ja modifioitu neutraali selluloosa 2 (MNS2) paransivat leivän joustavuutta. MNS2 lisäsi myös leipien kimmoisuutta, kun taas MNS1:llä ei ollut vaikutusta ja GM pienensi leipien kimmoisuutta. Myös seitsemännen säilytyspäivän jälkeen MNS1 piti leivän rakennetta joustavampana muihin saman ikäisiin leipiin verrattuna. Käytetyillä hydrokolloideilla ei ollut tilastollista eroa leivän kovuudessa, pureskeltavuudessa eikä murtumisherkkyydessä. Selkeitä eroja leivissä näkyi aistinvaraisesti arvioituna vain huokosjakaumassa. Huokosjakaumalta epätasaisimpia olivat leivät, joissa oli käytetty MNS1 tai MNS2 tasolla 3. Leipien säilönnän aikana oli kuitenkin huomattavissa selkeää kuivumista ja kovettumista. Leivonnasta seitsemännen päivän kohdalla lähes kaikki leivät olivat todella kovia ja sisus oli kuiva. Leipien maku oli myös heikentynyt aiempiin päiviin verrattuna. Tutkittujen hydrokolloidien vaikutusta leivän pehmeyteen ja nautittavuuteen ei voida todentaa tehtyjen tutkimusten perusteella, aistinvaraisesti arvioituna leivät eivät olleet selkeästi pehmeämpiä hydrokolloidilisäysten myötä.
  • Pitkänen, Paula (2019)
    Gluten free baking differentiates from traditional wheat baking by the lack of structure stabilizing gluten network. The gluten in wheat flour mixed with water creates a visco-elastic dough that makes a good quality bread. In gluten free baking the structure of bread is improved with starches and hydrocolloids. Celiac decease, gluten yliherkkyys and wheat allergy are health related reasons to avoid gluten from wheat, barley and rye. There is no method for gluten free flours to predict the quality of the baked product like there is the farinograph water absorption method for wheat flour. These topics are discussed in the literature part of this work. The aim of this research was to look into the connection between gluten free dough consistency and the quality of baked bread. In the experimental part three different dough yields were selected: 190, 200 and 210. All dough yields were used with three different mixtures in consistency measurements: 100% buckwheat, 70 % buckwheat and 30 % tapioca and addition of 1 % psyllium to the latter mixture. Two different methods were tested (forward and backward extrusion) with Texture Analyser with all different dough variations. The principle in both methods are the same: the tests measure the compression force required for a piston to extrude the dough in a sample container. The doughs consistency and behavior were studied with farinograph to see if the results were consistent. Baking test was done with different dough yields with buckwheat, tapioca and psyllium mixture. Volume, baking loss and color were determined. Texture Profiler Analysis (TPA) was done 24h and 48h after baking. A sensory analysis conducted by professional panelists was done where porosity, softness, dryness, sponginess and intensity of buckwheat taste were assessed. Backward extrusion was found to be a better method for measuring consistency of the doughs. The results showed how the increasing water amount decreased consistency and same results were obtained with farinograph. Differences between breads were found with the sensory analysis as well. Intensity of flavor and porosity increased in bread with lower water amount whereas softness and moistness increased with increasing water amount when also the bread remained softer for longer. As a conclusion it can be stated that the backward extrusion is a suitable and reproducible method for buckwheat dough consistency measurements. Water absorption, bread structure and shelf life can be predicted and optimized based on consistency.
  • Aaltonen, Saara-Sofia (2021)
    The beneficial nutritional quality of oats and the recognition as a naturally gluten-free grain has increased its popularity. In the baking of wholemeal oat bread, the absence of gluten complicates the handling of the dough, and the oat cultivars differ in their baking quality a lot. For now, test baking is the only way to optimize whole oat baking. The aim of this study was to define how oat cultivars differ in their baking quality and how to adjust the dough yield for optimal baking result. The hypothesis was that oat varieties grown in different fields bake differently and by optimizing the dough consistency with dough yield, baking result can be improved. The work examined three oat cultivars and a total of five oat flour samples in the baking of palabread i.e. flat, yeast proofed bread. Moisture content, beta-glucan, and protein contents, pasting curves, particle sizes of flour and water binding were determined from the samples according to standard methods. All flour samples were baked first with dough yield of 215. The consistencies of doughs were measured with backward extrusion method by Texture Analyzer device. Based on the oat bread that proved to be the best in test baking, the optimal level of consistency was determined, to which dough yields were adjusted for the following baking tests. Breads baked with dough yields of 215 and breads obtained from optimized consistencies were compared sensorially and bread staling was measured by the hardness of the crumb for three days after baking. Oat cultivars differed in beta-glucan and protein contents. High beta-glucan and protein content of oat flour resulted in higher water-binding capacity and higher dough consistency. The low water-binding capacity of oat flour was associated with greater drying of the breads and faster aging. Moisture was bound better to the bread when the water-binding capacity of the oat was higher. The consistencies of the dough varieties of oat cultivars differed significantly with the same dough result, and the consistencies obtained from different flour samples of the same cultivars also differed from each other. There were no major sensory differences in the oat breads of the study, but breads baked from different oat flours differed in hardness and aging rates, even though the breads were baked with the same dough consistencies. The optimization of the consistency evened out the quality differences between the oat samples and improved the work-ability of the dough. The optimization was found to be successful in modifying handling of the dough and the structure of the baked bread in desired direction.
  • Coleman, Patience (2015)
    The glycolytic potential of muscles is a representation of the energy reserve of a muscle and takes into account all compounds that are present in the muscle, which can be converted into lactic acid. A total of 219 breast muscle samples from five hybrids of male broiler chickens were used in this study. All from fast growing lines, they hybrids used are Ross 508, Cobb, Hubbard H1, Ross 308 and Rowan. The birds were reared under the same conditions, and slaughtered randomly at different ages. The pH, initial and ultimate, glycogen and lactic acid were assessed in all the samples. The glycolytic potential was calculated using results from the lactate and glycogen analysis. Older birds were associated with low glycogen concentrations. Wooden Breast muscles showed a very high significant difference with pHu (P<0.0001) and high significant difference with glycolytic potential (P = 0.0004). Affected breast muscles were associated with high pHu values and low glycolytic potential, where there was strong positive correlation between pHu and Wooden Breast presentation (P<0.0001, r = 0.414), and a weak negative correlation between the glycolytic potential and the presentation of Wooden Breast (P<0.0001, r = -0.292). Among the hybrids, Hubbard H1 recorded the highest glycolytic potential mean value of 117.22 while Ross 308 had the least mean value of 105.9 ± 5.6.
  • Saarinen, Petri (2014)
    Enterococci is a group of gram positive bacteria part of human intestinal flora. While generally harmless, several species of the group are known to cause severe infections in humans, including bloodstream infections leading to sepsis. Since Enterococci are naturally resistant to many antibiotics, the use of glycopeptides, considered a”last resort” drugs, is common in treatment of enterococcal infections. In recent years, however, the emergence of glycopeptide resistant Enterococci (GRE) has been an increasing concern for clinics and microbiology laboratories around the world, creating a need for fast and accurate screening tests differentiating the glycopeptide resistant Enterococcus strains from the non-resistant ones. In this study, a combined PCR and microarray hybridization based method for identification of the clinically most prevalent GRE was established as a part of commercial sepsis diagnostic test called Prove-it™ Sepsis. Already identifying the most common Enterococcus species (E.faecium and E.faecalis), the detection of glycopeptide resistance causing ligase genes vanA and vanB and species level identification of intrinsically glycopeptide resistant E.gallinarum and E.casseliflavus were added as part of the the test. Primers were designed for sequencing vanA and vanB genes and multiple strains, provided by a Finnish clinical laboratory Huslab, were sequenced. Sequence regions unique to these genes were identified according to sequence alignment data containing the sequenced gene regions and other relevant sequences found in public sequence databases. Based on these data, primers were designed for the amplification of the selected gene regions. For identification of the amplified gene regions, a set of hybridization probes were designed and printed on microarray. In addition, probes for identifying E.casseliflavus and E.gallinarum were designed based on sequence aligment data gathered from Mobidiag Ltd. private biobank. The identification of these species was based on topoisomerase encoding gyrB gene amplified by the Prove-it™ Sepsis broad range PCR. Several primers for the amplification of vanA and vanB genes were designed and one primer pair for each was selected to be integrated to the Prove-it™ Sepsis multiplex-PCR. Similarily, multiple hybridization probes were designed for detecting vanA, vanB, E.casseliflavus and E. gallinarum. Four probes for each target gene region were selected to be integrated to the commercial test. With this modified test, 12 pure culture samples of clinical origin were tested and the results were compared to the ones provided by the laboratory of clinical microbiology of Hôspital de bicêtre (Paris, France). Results provided by the modified PCR and microarray test were identical to the reference results in 11 out of 12 cases.
  • Salovaara, Anna-Kaisa (2019)
    Jääsalaattia (Lactuca sativa var. crispa L.) tuotetaan ympärivuotisesti kasvihuoneessa ja se on kuluttajien keskuudessa suosittu lehtivihannes. Jääsalaatti kerää monien muiden lehtivihannesten tapaan nitraattia ja sen nitraattipitoisuudet voivat nousta melko suuriksikin. Jääsalaatin nitraattipitoisuuteen vaikuttavat useat eri tekijät, kuten laji, lajike, lannoitustaso ja valon intensiteetti. Tehokkailla nitraattipitoisuuden hallintakeinoilla voidaan parantaa tuottajan mahdollisuuksia vaikuttaa sadon laatuun. Valtaosa ravinnon mukana saatavasta nitraatista on peräisin lehtivihanneksista. Euroopan unioni on asettanut katteen alla kasvatetun salaatin nitraattipitoisuudelle talvi- ja kesäkauden raja-arvot. Nitraatti on ihmisen terveydelle haitallinen yhdiste, sillä osa siitä muuttuu elimistössä nitriitiksi, mikä kasvattaa etenkin pienten lasten methemoglobinemian riskiä. Glysiinibetaiini on osmolyytti ja solun metabolian kanssa yhteensopiva yhdiste. Monet viljelykasvit syntetisoivat glysiinibetaiinia vasteena abioottisille stresseille ja se parantaa kasvien stressinkestävyyttä myös eksogeenisesti annettuna. Glysiinibetaiinia saadaan ravinnon mukana esimerkiksi viljatuotteissa ja se on ihmisille turvallinen yhdiste, jota voidaan käyttää myös ravintolisänä. Glysiinibetaiinia eristetään muun muassa sokerijuurikkaan melassista ja sitä voidaan käyttää orgaanisena lannoitteena tai kasvunedistäjänä kasvintuotannossa. Tämän tutkimuksen tavoitteena oli selvittää glysiinibetaiinin käyttömahdollisuuksia jääsalaatin tuotannon edistäjänä. Kasvihuonekokeessa seitsemän vuorokautta kestänyt glysiinibetaiinikäsittely aloitettiin jääsalaattien ollessa 29 vuorokauden ikäisiä. Glysiinibetaiinikäsittelyjen pitoisuudet olivat 0, 1, 7,5 ja 15 mM. Jääsalaatin nitraattipitoisuus, glysiinibetaiinipitoisuus sekä tuore- ja kuivamassa määritettiin 24, 29, 36, 41 ja 49 vuorokauden ikäisistä kasveista. Tutkimus toteutettiin kiertovesiviljelyjärjestelmässä ja glysiinibetaiinikäsittely annettiin ravinneliuoksessa. Jääsalaatit ottivat eksogeenisesti annettua glysiinibetaiinia. Glysiinibetaiinikäsittely pienensi jääsalaatin nitraattipitoisuutta seitsemän vuorokauden käsittelyn jälkeen merkitsevästi kontrolliin verrattuna ja alenema oli suoraan verrannollinen käsittelyn pitoisuuteen. Lisäksi glysiinibetaiinikäsittely pienensi jääsalaatin tuorepainoa ja suurensi kuiva-ainepitoisuutta. Määrityksissä myös jääsalaatin glysiinibetaiinipitoisuuden havaittiin olevan suoraan verrannollinen käsittelyn pitoisuuteen.
  • Virolainen, Savi (2018)
    Erityisesti taloudellisissa ilmiöissä sekä niitä kuvaavissa aikasarjoissa esiintyy usein vaihtelua eri tilojen välillä, esimerkiksi markkinoiden vakauden heilahtelun aiheuttamana. Eri tilojen välillä vaihtelua selittämään kykeneviä aikasarjamalleja ovat muun muassa autoregressiiviset sekoitusmallit. Tällaisia ovat esimerkiksi GMAR-malli (Gaussian Mixture Autoregressive) ja StMAR-malli (Student's t Mixture Autoregressive), joihin perustuen tutkielmassa esitetään molempien piirteitä hyödyntävä G-StMAR-malli (Gaussian and Student's t Mixture Autoregressive). Autoregressiiviset sekoitusmallit voidaan ajatella kokoelmaksi lineaarisia autoregressiivisiä malleja, joista kutakin kutsutaan mallin komponentiksi. Kunkin komponentin ajatellaan kuvaavan kutakin ilmiössä esiintyvää tilaa. GMAR-mallissa komponenttien oletetaan olevan normaalisia autoregressiivisiä prosesseja, kun taas StMAR-mallissa ne ovat t-jakaumaan perustuvia, ehdollisesti heteroskedastisia autoregressiivisiä prosesseja. StMAR-mallin komponenttien ehdollisen varianssin riippuvuus samoista parametreista kuin ehdollinen odotusarvo voi kuitenkin olla rajoittava tekijä tapauksissa, joissa komponenttikohtainen ehdollinen odotusarvo on vahva, mutta ehdollinen varianssi heikko. Tästä syystä StMAR-malli yleistetään tutkielmassa G-StMAR-malliksi sallimalla osan sen komponenteista perustuvan GMAR-mallin käyttämiin normaalisiin autoregressiivisiin prosesseihin, joissa ehdollisen varianssin oletetaan olevan vakio. Tutkielmassa esitellään GMAR-malli ja StMAR-malli, ja määritellään niiden pohjalta G-StMAR-malli. Lisäksi osoitetaan, että GMAR-mallin ja StMAR-mallin houkuttelevat teoreettiset ominaisuudet, kuten ergodisuus ja stationaarisen jakauman tunteminen, periytyvät ilmeisellä tavalla myös G-StMAR-mallille. Mallien esittelemisen jälkeen tutkielmassa kerrotaan lyhyesti, kuinka esitetyt mallit voidaan estimoida kaksivaiheista menetelmää käyttäen, miten malleille voidaan valita sopivat asteet, kuinka kvantiiliresiduaaleja voidaan hyödyntää mallin sopivuuden tarkastelemisessa ja miten taustalla olevan prosessin tulevia havaintoja voidaan ennustaa simulaatiomenettelyllä. Tutkielman empiirisessä osiossa tutkitaan, millaisiksi G-StMAR-mallin parametrit estimoituvat pohjana olevaan StMAR-malliin verrattuna, ja lisäksi mallien ennustetarkkuuksia vertaillaan toisiinsa. Esimerkkiaineistona käytetään Standard & Poor's 500 osakemarkkinaindeksin päivittäistä volatiliteettia kuvaavaa, ajanjakson 3.1.2000-20.5.2016 kattavaa aikasarjaa. Tutkielman tulosten perusteella StMAR- ja G-StMAR-mallien ennustetarkkuuksien välillä ei voida sanoa olevan juurikaan eroa, mutta joissakin tapauksissa voidaan G-StMAR-malliin siirtymällä välttää StMAR-mallin parametrien estimaatteja koskevia ongelmia.
  • Karttunen, Henri (2015)
    Aikasarjoissa ilmenevien ei-normaalisten piirteiden mallintamiseen voidaan käyttää epälineaarisia aikasarjamalleja, joista erityisesti tutkielmassa tarkastellaan autoregressiivisia sekoitusmalleja. Autoregressiiviset sekoitusmallit määritellään sekoituksena lineaarisista autoregressiivisista malleista ja erona eri sekoitusmallien välillä on niiden sekoitussuhteiden määrittely. Autoregressiivisella GMAR (Gaussian Mixture Autoregressive)-sekoitusmallilla on houkuttelevia teoreettisia ominaisuuksia, sillä sen stationaarinen jakauma tunnetaan ja sen stationaarisuusehto ja ergodisuus voidaan johtaa ilman lisärajoituksia parametreille. Kuitenkin sekoitussuhteiden monimutkaisesta määrittelystä johtuen sen parametrien estimointi käyttäen kirjallisuudessa usein käytettyä EM-algoritmia on hankalaa. Tästä syystä tutkielmassa selvitetään mahdollisuutta käyttää parametrien estimoinnissa kaksivaiheista menetelmää, jossa geneettisen algoritmin avulla etsitään alkuarvoja gradienttiperusteiselle optimointialgoritmille. Parametrien estimoinnin lisäksi tutkielmassa tarkastellaan mallinvalintaa osana estimointiprosessia. Tarkasteltavia työkaluja sopivan mallin etsinnässä ovat informaatiokriteerit sekä erilaiset kvantiiliresiduaaleihin perustuvat testit, joiden avulla voidaan tehdä mallidiagnostiikkaa tavallisten residuaalien tapaan myös silloin, kun tavallisia residuaaleja ei voida käyttää. Lisäksi tarkastellaan ennusteiden laskemista simulaatioiden avulla ja esitetään miten GMAR-mallia voidaan simuloida. Tutkielman empiirisessä osassa tarkastellaan kahta esimerkkiä, joista ensimmäisessä keskitytään estimointiin, mallinvalitaan ja diagnostiikkaan. Tässä esimerkissä aineistona käytetään yhdysvaltain kuukausittaista inflaatiota vuodesta 1975 vuoteen 2015. Toisessa empiirisessä esimerkissä tarkastellaan tuulen nopeuksia päivittäisen aineiston avulla ja keskitytään erityisesti ennusteiden laskemiseen. Tuulen nopeutta mittaava aineisto on ei-negatiivinen aikasarja ja siksi esimerkissä tarkastellaan estimointia logaritmoidun sarjan avulla ja alkuperäisen sarjan ennustamista. Tutkielman tulosten perusteella kaksivaiheinen estimointi käyttäen geneettistä algoritmia toimii GMAR-mallin tapauksessa hyvin ja kohtuullisessa ajassa.
  • Mäki, Jasmin (2018)
    Genetically modified (GM) crops are subject to fierce debates. The scientific controversy and novelty of the technology raise concerns over possible adverse effects. On the other side, promoters of the technology argue for the safety and economic benefits. These debates take place within the public sphere, where meanings about GM crops are socially constructed. This research describes the national debates over GM crops in the newspapers of the United States and Spain. Six newspapers were searched giving a final sample of 244 articles, of which 152 were further analysed. The articles were coded following the method of political claim-making to find out who discusses GM crops and how. The theoretical framework combines framing theory with the theory of discursive opportunity structure (DOS). The results are six opposing frames about agrobiotechnoloy: economic benefits and costs, biosafety and risk, and progress and critique. Though issues and contexts vary greatly in the two countries, the arguments are influenced by the transnational discursive opportunity structure, meaning the international treaties that govern GM agriculture. Those establish scientific risk assessments over human health and environment as the base for decisions about GM agriculture. The second part of the analysis examines the influence of the transnational DOS on how social movements frame GM crops as risks. The way mass media interprets DOS influences on how it restricts or enables strategic arguing by social movements. The analysis reveals that movements apply environmental and health risk frames and use scientific arguments to influence in GM politics. However, the success of the movements depends on various national components of the DOS and the support from other actors. In Spain, movements state unknown risks, relying on the precautionary principle applied in the European Union. In the U.S., many risks have already materialized and movements centre on demanding corrective measures, since it is difficult to challenge the dominant agricultural model. National policy discourses and political cultures explain the differences between the countries. In the U.S., movements manage to make labeling a big issue, turning the discussion to a matter of individual choice and consumer rights.
  • Häggman, Verner (2019)
    If pharmaceutical quality system fails it causes a hazard to the patient’s health, but also to the manufacturer’s economy. For this reason, the manufacturer’s must make sure their products comply with the quality requirements placed by authorities. To ensure the compliance, the authorities perform inspections at the manufacturing sites. If the site does not comply with the quality requirements, the authority will take necessary measures. The goal of this study was to find what type of quality issues FDA and the authorities within EU have observed while inspecting manufacturing facilities, which of these issues are most common, in which countries the sites companies with issues have been located. The results were assessed from European pharmaceutical company’s point of view. The data for the study was collected from Eudra GMDP database and from FDA Warning letters sent by FDA headquarters from years 2015-2017. Qualitative analysis of content was chosen as the method of analysis. The collected data was classified into main classes and subclasses based on reoccurring topics. The classes were transferred in tables to compare how which of the classes were most common. Most often the facilities with quality issues were located in China and India. The authorities also perform a lot of quality inspections in these countries, but that alone doesn’t explain the large number of quality issues in these countries. The number of sites with quality issues per inspection was also high. Both the authorities of EU countries and FDA had mainly observed similar issues. Often quality issues were related to data integrity. Other common themes were quality management system, cleaning of equipment and facilities and analytical methods. There were also some differences in the observed issues. E.g. FDA had rarely observed issues related to personnel while EU authorities had observed such issues frequently. Quality issues which had led to measures by authorities were often related to larger problems with the quality management or to very basic quality actions. If company doesn’t have well-functioning quality organization, the quality system is often inadequate also in other ways. By comparing their own activities with the issues observed at other companies, it is easier for a company to improve their quality and avoid major quality issuer before they occur.