Pre- and postnatal nutrition – target for allergy risk reduction

A rapid increase in allergic diseases in Western societies has led to the conclusion that our modern lifestyle is a risk factor for immune dysregulation. Potential culprits and benefactors are searched among early dietary and microbial exposures, which may act to program later allergic disease. The aim of this thesis was to investigate the role of early maternal and child nutrition in reducing the risk of child allergy. The study population comprised of 256 mother – child pairs from families with a history of allergy participating in a randomized controlled dietary counseling and probiotic intervention (Lactobacillus rhamnosus GG and Bifidobacterium lactis Bb12) study from early pregnancy onwards. The dietary counseling aimed for a diet complying with dietary recommendations for pregnant and lactating women, with special attention to fat quality. Maternal dietary counseling was reflected in cord blood fatty acids suggesting better essential fatty acid status in infants in the counseling group. Dietary counseling with probiotics or placebo had no effect on child allergy risk, but associations between maternal diet during pregnancy and breastfeeding and child allergic outcomes were found in secondary analyses. During pregnancy, milk intake was related to decreased and cheese intake to increased risk of child atopic eczema. During breastfeeding, intake of vitamin C was related to increased risk of asthma and intake of egg was related to decreased risk of atopic eczema. The timing of introduction of complementary foods to infant’s diet was not associated with risk of atopic eczema, when adjusted with parental opinion of child allergic symptoms (i.e., potential reverse causality). In conclusion, the results demonstrate that infant fatty acid supply can be modified via maternal dietary changes. In addition, interesting associations of maternal diet with child allergy risk were discovered. However, no difference in the incidence of allergic diseases with dietary counseling was observed. This suggests that more potent dietary interventions might be necessitated to induce clinical risk reduction of allergy. Highrisk families can safely adhere to dietary recommendations for pregnant and lactating women, and the results support the current conception that no additional benefit is gained with delaying introduction of complementary feeding.

The tightness performance of pre-formed trays as package

Suojakaasupakkaaminen (MAP) on yleistynyt viime aikoina, koska sen avulla voidaan säilöä tuoreita tai vähän käsiteltyjä elintarvikkeita pidempään. Suurin syy hyllyiän pidentymiseen on hiilidioksidin aiheuttama mikrobien kasvun hidastuminen. Toisaalta huolena on patogeenisten mikrobien lisääntyminen anaerobisissa olosuhteissa. Pidempi säilyvyys voidaan saavuttaa myös käyttämällä vähemmän lisä- ja säilöntäaineita. Samalla suojakaasupakkaaminen kuitenkin vähentää myös pilaantuneiden tuotteiden määrää. Eniten suojakaasua käytetään lihan pakkaamisessa. Suojakaasupakkaamisessa elintarvikepakkaukseen syötetään normaalista huoneilmasta poikkeava kaasuseos. Pääasiassa kaasuseos koostuu hiilidioksidista, hapesta ja typestä. Lisäksi voidaan käyttää pieniä määriä hiilimonoksidia, argonia ja rikkidioksidia. Kaasuseoksen koostumus määräytyy elintarvikkeiden ominaisuuksien ja vaatimusten perusteella. Halutun kaasukoostumuksen tulee säilyä pakkauksessa muutamasta päivästä muutamaan kuukauteen riippuen elintarvikkeesta. Siksi tärkein pakkaukselta vaadittava ominaisuus on riittävä kaasutiiveys ja erityisesti hapenläpäisevyys. Koska suurin osa suojakaasupakkauksista on tällä hetkellä muovisia, tutkittiin kokeellisessa osiossa kartonkipakkausten tiiveysominaisuuksia. Kokeet tehtiin vertailemalla erilaisten vuoka- ja kansimateriaalien vaikutusta pakkausten tiiveyteen. Vuokien onnistuminen oli suurin yksittäinen tuloksiin vaikuttanut tekijä. Epäonnistuneen vuoan vaikutukset näkyivät myös saumauksessa, koska saumaustyökalun ja vuoan piti sopia yhteen. Lisäksi näkymättömät mikroreiät hankaloittivat todellisten vuotokohtien paikallistamista. Vuototestausten perusteella materiaaleille löydettiin kuitenkin viitteelliset optimiparametrit. Tärkein saumauksessa vaikuttanut tekijä oli sopivan saumauslämpötilan valinta. Prässättyjen vuokien laatu oli epätasainen. Siksi erityisesti rinnakkaisten kansitus- ja hapenläpäisymittausten väliset erot olivat merkitseviä. Lisäksi prässäys laski materiaalien hapenläpäisyominaisuuksia. Yksittäisten vuokien tiiveysominaisuudet täyttivät kuitenkin kaupallisille kaasupakkauksille asetetut vaatimukset. Vesihöyrynläpäisevyydessä materiaalin vesihöyrynläpäisy oli merkittävämpää kuin vesihöyryn kulkeutuminen vuotokohtien tai epäonnistuneiden saumojen kautta.

Virus Infections in Early Childhood, Cow’s Milk Formula Exposure and Genetic Predisposition in the Development of Diabetes-Associated Autoimmunity

Varhaislapsuuden virusinfektioiden, lehmänmaitopohjaisen äidinmaitovastikeen ja geneettisen alttiuden merkitys diabetekseen liittyvän autoimmuniteetin kehittymisessä Tyypin 1 diabetes on autoimmuunisairaus, joka syntyy haiman insuliinia tuottavien beta-solujen tuhouduttua elimistön oman immuunipuolustusjärjestelmän hyökkäyksen seurauksena. Sekä perimän että ympäristötekijöiden arvellaan vaikuttavan tautiprosessiin, mutta taudin tarkkaa syntymekanismia ei tunneta. Tutkimuksen tarkoituksena oli selvittää varhaislapsuuden ympäristötekijöiden vaikutusta beta-soluautoimmuniteetin syntyyn, erityispaino tutkimuksessa oli ympäristötekijöiden yhteisvaikutuksessa sekä geneettisten riskitekijöiden ja ympäristötekijöiden vuorovaikutuksessa. Varhaislapsuudessa sairastettu sytomegalovirus- tai enterovirusinfektio ei lisännyt beta-soluautoimmuniteetin riskiä lapsilla, joilla on geneettisesti kohonnut riski sairastua tyypin 1 diabetekseen. Ennen puolen vuoden ikää sairastettu rotavirusinfektio lisäsi hieman tyypin 1 diabetekseen liittyvän autoimmuniteetin riskiä. Tarkemmassa analyysissa varhaislapsuuden enterovirusinfektio osoittautui kuitenkin autovasta-aineiden muodostumisen riskitekijäksi niiden lasten joukossa, jotka olivat saaneet lehmänmaitopohjaista äidinmaidon vastiketta ensimmäisten elinkuukausien aikana. Tämä löydös viittaa enterovirusinfektion ja lehmänmaitopohjaisen vastikkeen yhteisvaikutukseen tyypin 1 diabetekseen liittyvän autoimmuniteetin synnyssä. Löydösten mukaan PTPN22 geenin C1858T polymorfismi vaikuttaa CD4+ T solujen aktivaatioon ja proliferaatiovasteeseen, 1858T alleeliin liittyy alentunut T-soluresepto-rivälitteinen aktivaatio. 1858T alleelin kantajuuteen liittyy lisäksi lisääntynyt autovasta-aineiden ja kliinisen diabeteksen ilmaantuvuus. Tämä yhteys rajoittui yksilöihin, jotka olivat altistuneet lehmänmaitopohjaiselle vastikkeelle ennen kuuden kuukauden ikää. Tulosten mukaan sekä ympäristötekijöiden väliset yhteisvaikutukset että perimä vaikuttavat yksittäisen ympäristötekijän merkitykseen tyypin 1 diabetekseen liittyvän autoimmuniteetin synnyssä. Nämä yhteisvaikutukset ympäristötekijöiden kesken ja perimän ja ympäristötekijöiden välillä selittävät aiemmin julkaistujen tulosten ristiriittaisuutta tutkimuksissa, joissa on analysoitu vain yhden ympäristötekijän vaikutusta diabeteksen ilmaantuvuuteen.

Winner-Loser Performance and Macroeconomic Effects during three last Economic Crises in Finnish Stock Market

The main purpose of this thesis is to investigate winner-loser performance when financial markets are facing crisis. This is examined through the idea that does the prior loser portfolios outperform the prior winner portfolios during the three major crises: The depression of the 1990s, the IT-Bubble and the Subprime -crisis. Firstly, the winner and loser portfolios superiority is counted by using the cumulative excess returns from the examination period. The portfolios were formed by counting the excess returns and locating them in to the order of superiority. The excess returns are counted by using one year pre-data before the actual examination period. The results of this part did not support the results of De Bondt & Thaler’s (1985) paper. Secondly, it is investigated how the Finnish and the US macroeconomic factors are seen to be affecting the stock market valuation in Finnish Stock Markets during economic crises. This is done to explain better the changes in the successes of the winner-loser performance. The crises included different amount of selected macro factors. Two latest crises involved as well few selected US macro factors. Exclusively the IT-Bubble -crisis had the most statistically significant results with the US factors. Two other crises did not receive statistically significant results. An extra research was produced to study do the US macro factors impact more significantly on Finnish stock exchange after lags. The selected lags were three, six, nine and twelve months. Three and six month lagged US macro factors during the IT-Bubble -crisis improved the results. The extra research did not improve the results of the Subprime -crisis.

Nocturnal Transcutaneous Carbon Dioxide and Early Changes in Atherosclerosis in Pre- and Postmenopausal Women

The risk of cardiovascular diseases and sleep-disordered breathing increases after menopause. This cross-sectional study focuses on overnight transcutaneous carbon dioxide (TcCO₂) measurements and their power to predict changes in the early markers of cardiovascular and metabolic diseases. The endothelial function of the brachial artery, the intima-media thickness of the carotid artery, blood pressure, glycosylated hemoglobin A1C and plasma levels of cholesterols and triglycerides were used as markers of cardiovascular and metabolic diseases. The study subjects consisted of healthy premenopausal women of 46 years of age and postmenopausal women of 56 years of age. From wakefulness to sleep, the TcCO₂ levels increased more in postmenopausal women than in premenopausal women. In estrogen-users the increase in TcCO₂ levels was even more pronounced than in other postmenopausal women. From the dynamic behaviour of the nocturnal TcCO₂ signal, several important features were detected. These TcCO₂ features had a remarkable role in the prediction of endothelial dysfunction and thickening of the carotid wall in healthy premenopausal women. In addition, these TcCO₂ features were linked with blood pressure, lipid profile and glucose balance in postmenopausal women. The nocturnal TcCO₂ profile seems to contain significant information, which is associated with early changes in cardiovascular diseases in middle-aged women. TcCO₂ might not only measure the tissue carbon dioxide levels, but the TcCO₂ signal variation may also reflect peripheral vasodynamic events caused by increased sympathetic activity during sleep.

Early nutritional determinants in cardio-metabolic programming – A prospective randomized controlled dietary intervention study

Western societies have been faced with the fact that overweight, impaired glucose regulation and elevated blood pressure are already prevalent in pediatric populations. This will inevitably mean an increase in later manifestations of cardio-metabolic diseases. The dilemma has been suggested to stem from fetal life and it is surmised that the early nutritional environment plays an important role in the process called programming. The aim of the present study was to characterize early nutritional determinants associating with cardio-metabolic risk factors in fetuses, infants and children. Further, the study was designated to establish whether dietary counseling initiated in early pregnancy can modify this cascade. Healthy mother-child pairs (n=256) participating in a dietary intervention study were followed from early pregnancy to childhood. The intervention included detailed dietary counseling by a nutritionist targeting saturated fat intake in excess of recommendations and fiber consumption below recommendations. Cardio-metabolic programming was studied by characterizing the offspring’s cardio-metabolic risk factors such as over-activation of the autonomic nervous system, elevated blood pressure and adverse metabolic status (e.g. serum high split proinsulin concentration). Fetal cardiac sympathovagal activation was measured during labor. Postnatally, children’s blood pressure was measured at six-month and four-year follow-up visits. Further, infants’ metabolic status was assessed by means of growth and serum biomarkers (32-33 split proinsulin, leptin and adiponectin) at the age of six months. This study proved that fetal cardiac sympathovagal activity was positively associated with maternal pre-pregnancy body mass index indicating adverse cardio-metabolic programming in the offspring. Further, a reduced risk of high split proinsulin in infancy and lower blood pressure in childhood were found in those offspring whose mothers’ weight gain and amount and type of fats in the diet during pregnancy were as recommended. Of note, maternal dietary counseling from early pregnancy onwards could ameliorate the offspring’s metabolic status by reducing the risk of high split proinsulin concentration, although it had no effect on the other cardio-metabolic markers in the offspring. At postnatal period breastfeeding proved to entail benefits in cardio-metabolic programming. Finally, the recommended dietary protein and total fat content in the child’s diet were important nutritional determinants reducing blood pressure at the age of four years. The intrauterine and immediate postnatal period comprise a window of opportunity for interventions aiming to reduce the risk of cardio-metabolic disorders and brings the prospect of achieving health benefits over one generation.

Corrosion behaviour of boiler tube materials during combustion of fuels containing Zn and Pb

Många förbränningsanläggningar som bränner utmanande bränslen såsom restfraktioner och avfall råkar ut för problem med ökad korrosion på överhettare och/eller vattenväggar pga. komponenter i bränslena som är korrosiva. För att minimera problemen i avfallseldade pannor hålls ångparametrarna på en relativt låg nivå, vilket drastiskt minskar energiproduktionen. Beläggningarna i avfallseldade pannor består till största delen av element som är förknippade med högtemperaturkorrosion: Cl, S, alkalimetaller, främst K och Na, och tungmetaller som Pb och Zn, och det finns också indikationer av Br-förekomst. Det låga ångtrycket i avfallseldade pannor påverkar också stålrörens temperatur i pannväggarna i eldstaden. I dagens läge hålls temperaturen normalt vid 300-400 °C. Alkalikloridorsakad (KCl, NaCl) högtemperaturkorrosion har inte rapporterats vara relevant vid såpass låga temperaturer, men närvaro av Zn- och Pb-komponenter i beläggningarna har påvisats förorsaka ökad korrosion redan vid 300-400 °C. Vid förbränning kan Zn och Pb reagera med S och Cl och bilda klorider och sulfater i rökgaserna. Dessa tungmetallföreningar är speciellt problematiska pga. de bildar lågsmältande saltblandningar. Dessa lågsmältande gasformiga eller fasta föreningar följer rökgasen och kan sedan fastna eller kondensera på kallare ytor på pannväggar eller överhettare för att sedan bilda aggressiva beläggningar. Tungmetallrika (Pb, Zn) klorider och sulfater ökar risken för korrosion, och effekten förstärks ytterligare vid närvaro av smälta. Motivet med den här studien var att få en bättre insikt i högtemperaturkorrosion förorsakad av Zn och Pb, samt att undersöka och prediktera beteendet och motståndskraften hos några stålkvaliteter som används i överhettare och pannväggar i tungmetallrika förhållanden och höga materialtemperaturer. Omfattande laboratorie-, småskale- och fullskaletest utfördes. Resultaten kan direkt utnyttjas i praktiska applikationer, t.ex. vid materialval, eller vid utveckling av korrosionsmotverkande verktyg för att hitta initierande faktorer och förstå deras effekt på högtemperaturkorrosion.

Bioactive Glass in Lumbar Spondylodesis. A Pre-Clinical and Clinical Study

Bioactive glasses (BGs) form a group of synthetic, surface-active, composition-dependent, silica-based biomaterials with osteoconductive, osteopromotive, and even angiogenic, as well as antibacterial, properties. A national interdisciplinary research group, within the Combio Technology Program (2003–2007), developed a porous load-bearing composite for surgical applications made of BG 1–98 and polymer fibers. The pre-clinical part of this thesis focused on the in vitro and in vivo testing of the composite materials in a rabbit femur and spinal posterolateral fusion model. The femur model failed to demonstrate the previously seen positive effect of BG 1–98 on osteogenesis, probably due to the changed resorption properties of BG in the form of fibers. The spine study was terminated early due to adverse events. In vitro cultures showed the growth inhibition of human mesenchymal stems next to BG 1–98 fibers and radical pH changes. A prospective, long-term, follow-up study was conducted on BG–S53P4 and autogenous bone used as bone graft substitutes for instrumented posterolateral spondylodesis in the treatment of degenerative spondylolisthesis (n=17) and unstable burst fractures (n=10) during 1996–1998. The operative outcome was evaluated from X-rays and CT scans, and a clinical examination was also performed. On the BG side, a solid fusion was observed in the CT scans of 12 patients, and a partial fusion was found in 5 patients, the result being a total fusion rate in all fusion sites (n=41) 88% for levels L4/5 and L5/S1 in the spondylolisthesis group. In the spine fracture group, solid fusion was observed in five patients, and partial fusion was found in five resulting in a total fusion rate of 71% of all fusion sites (n=21). The pre-clinical results suggest that under certain conditions the physical form of BG can be more critical than its chemical composition when a clinical application is designed. The first long-term clinical results concerning the use of BG S53P4 as bone graft material in instrumented posterolateral spondylodesis seems to be a safe procedure, associated with a very low complication rate. BG S53P4 used as a stand-alone bone substitute cannot be regarded as being as efficient as AB in promoting solid fusion.

Smoking during pregnancy and fetal brain development

Background: Although the knowledge of adverse effects of smoking during pregnancy has increased in recent years, more research is needed to gain a better understanding of the effects of smoking during pregnancy. Smoking exposure is the most common preventable factor that causes adverse pregnancy outcomes. Aims and Methods: First, data on smoking habits during pregnancy from the Nordic Medical Birth Registers was used to study the national differences in trends of smoking during pregnancy. Second, the effects of prenatal smoking exposure on fetal brain development, assessed by brain MRI at term age, were studied by using data from the multidisciplinary PIPARI Study consisting of a 6-year cohort of VLBW/VLGA infants (n = 232, of which 18.1% were exposed to prenatal smoking) born in Turku University Hospital, Finland. Third, the effects of prenatal smoking exposure on psychiatric morbidity and use of psychotropic medication were studied in a cohort of children born from 1987–1989 in Finland (n = 175,869, of which 15.3% were exposed). The data used were obtained from population-based longitudinal registers from the National Institute of Health and Welfare, the Statistics Finland, and the Finnish Social Insurance Institution. Results: Smoking rates during pregnancy differed considerably between the countries. Smoking rates were highest among teenagers and women with lower socioeconomic positions. The smoking prevalence was found to be increasing among teenagers in both Finland and Norway. Prenatal smoking exposure was associated with smaller frontal lobe and cerebellar volumes in preterm infants. A clear association was found between prenatal smoking exposure and psychiatric morbidity treated with specialized hospital care and the use of various psychotropic medications. Conclusions: Prenatal smoking exposure had adverse effects on fetal brain development. These effects might explain part of the association found between smoking exposure and psychiatric problems in later life. Our study suggests that prenatal smoking exposure is linked with both mild and severe psychiatric problems. This study emphasizes the importance of efforts to reduce smoking during pregnancy.

Individual dietary counselling during and after pregnancy: Impact on diet and body weight

In Finland, maternity and child health clinics play a key role in promoting health in young families. Currently, obesity causes the greatest challenges to clinics. In obese pregnant women, an increased risk for metabolic diseases exist which can affect both the mother and child. The purpose of this thesis was to explore the role of dietary counselling: in Finnish health clinics; in the regulation of dietary intake; and in affecting the body weight of women. The main aim was to test the effect of dietary counselling and probiotic intervention on dietary intake and maternal body weight during and after pregnancy. In addition to dietary counselling, the effect of other factors, such as eating behaviour on dietary intake and body weight control after pregnancy was assessed. Another aim was also to evaluate dietary counselling practices by nurses (n = 327) in Finnish health clinics assessed by a questionnaire. At the beginning of the pregnancy, women (n = 256) enrolled in a dietary intervention study, were randomised into three groups. One group received dietary counselling with probiotics, one had counselling with placebo and the third group was the control group. The control group consisted of women whom did not receive counselling and took placebo. Probiotics and placebo supplements were used until the end of exclusive breastfeeding or six months after pregnancy. Women were followed from early pregnancy up to four years after pregnancy. Follow-up visits took place three times during pregnancy, at one and six months, and one, two and four years after pregnancy. Dietary counselling, provided by a nutritionist, aimed to influence the quality of dietary fat intake. Dietary counselling is important to provide in clinics, as determined by the nurses, and these nurses expressed a want to improve their own nutritional knowledge through education. The nurses had varying knowledge of current dietary recommendations. Dietary counselling for women during and after pregnancy resulted in beneficial changes in dietary intake up to one year after pregnancy and body weight and waist circumference up to four years after pregnancy. Probiotics had a beneficial effect together with dietary counselling on waist circumference until one year after pregnancy, but not throughout the long term, four years after pregnancy. Other factors, such as eating behaviour, associated with dietary intake and body weight control after pregnancy. Specifically, dietary recommendations are reached amongst women whom had high cognitive restraint in their eating behaviour and did not demonstrate uncontrolled eating. Overweight women more frequently emotionally ate compared to normal weight women and women with central adiposity related more frequently to having an uncontrolled eating behaviour than women with normal waist circumference. In addition, being overweight prior to pregnancy and excessive weight gain during pregnancy associated with increased body weight retention after pregnancy. This study showed that individual dietary counselling is useful in influencing dietary intake which adheres to dietary recommendations and this counselling influences, favourably, body weight after pregnancy. Especially, women with the risk for weight retention, such as women who have emotional and uncontrolled eating behaviours, who were overweight prior to pregnancy or those who had excessive weight gain during pregnancy, may benefit from individual dietary counselling. This study underscores the need to develop dietary counselling practices for pregnant women and their follow-up after pregnancy in Finnish health clinics. These practices include increasing the efficacy of the counselling such as collaboration with families, having knowledgable health professionals and having sufficient resources.

Lithostratigraphy and age of pre-Late Weichselian sediments in the Suupohja area, western Finland

Different types of laterally extensive sand- and gravel-dominated deposits, up to several tens of metres thick, were investigated in the Suupohja area of western Finland. The studied sediments were deposited in glacial, ice-marginal, glaciofluvial, sea or lake, littoral and terrestrial environments during several glacial-non-glacial cycles. Seventeen pre-Late Weichselian and three Late Weichselian/Holocene sedimentary units were identified. These were divided into ten formally and two informally defined formations that were together termed the Suupohja Group. Every unit are nevertheless not detectable throughout the study area. The informally defined “Karhukangas lower deposits” represent the lowest units in the Suupohja Group. The Karhukangas lower deposits with 5 till units, 3 glaciolacustrine/-marine units and 2 sand units, were interpreted as having been deposited during possibly four glacial-non-glacial cycles before the Late Pleistocene Subepoch (MIS 6 or earlier). The Kankalo Sand above the Karhukangas lower deposits comprises glaciofluvial and aeolian sands of Late Saalian, Eemian or Early Weichselian origin (MIS 6–MIS 5c). The Kariluoma Till above the Kankalo Sand was possibly deposited during the Late Saalian glacial advance, although an Early Weichselian origin is also possible. The Harrinkangas Formation, with glaciofluvial and quiet-water sediments, is interpreted as having been deposited during the Late Saalian and Eemian Stages (MIS 6–MIS 5e). The uppermost units in the deposits studied, the Kodesjärvi Formation (shore deposit), Isojoki Sand (aeolian), Rävåsen Formation (glaciofluvial), Vanhakylä Formation (shore line deposit), Dagsmark Till and Kauhajoki Till, were deposited during the Weichselian Stage (MIS 5d–MIS 2). In addition, Early Holocene (MIS 1) eskers without till cover were informally termed the “Holocene esker deposits”. The Lumikangas Formation represents gravelly shore deposits formed in the Holocene Epoch, when these areas last emerged from the sea. The first Weichselian ice expansion possibly reached the western part of Suupohja in the Early Weichselian Substage (MIS 5d?), but it did not expand further to the east. The second Weichselian glaciation of relatively short duration occupied the southern part of Finland in the later part of Middle Weichselian (MIS 3). Thus, the southern half of the country remained ice-free for the majority (~65–75%) of the Weichselian Stage. Instead, both humid temperate and periglacial conditions alternated. In the initial part of Middle Weichselian, this area was partly submerged, which indicates eastward expansion of the Scandinavian ice sheet(s), depressing the lithosphere. The exceptionally thick sediment cover, multiple lithofacies, relict landscape and preserved preglacially weathered bedrock are evidence of weak glacial erosion in the Suupohja area during the latest as well as earlier glaciations, making this area one of the key areas in Quaternary research.

Use of fiber-reinforced composite framework and thermochromic pigment in maxillofacial prostheses

The purpose of this investigation was to evaluate the possibility to enhance certain qualities of facial prostheses. Polymethyl methacrylate is still being used as base mate¬rial or clip carrier material, but it is hard and heavy, and debonding of the silicone from the acrylic base material is a frequent problem. This thesis aims to evaluate the use of fiber-reinforced composite (FRC) as framework material for maxillofacial silicone prostheses. FRC has been used as reinforcement in removable and fixed partial dentures since the 1990s. This material is lightweight and can be fabricated to compress the margins of the prosthesis slightly, to keep it tightly against the skin during jaw movements and facial expressions. Additionally, the use of a thermochromic pigment, colorless in room temperature and red in a cold environment, was studied in order to evaluate the possibility of using this color changing pigment in facial prostheses to mimic the color change of facial skin in cold weather. The tensile bond strength between pre-impregnated, unidirectional FRC and maxillofacial silicone elastomer was studied. Three different bonding agents or primers were compared. Bond strength was improved by one of the primers and by roughening the surface. The effect of a skin compressing glass fiber-reinforced composite framework on facial skin blood flow was studied by using a face mask, constructed with a compression pad corresponding to the outer margin of a glass fiber-reinforced framework beam of a facial prosthesis. The skin blood flow of ten healthy volunteers, aged 23-25 years, was measured during touch, light, and moderate compression of the skin, by using laser Doppler imaging technique. None of the compressions showed any marked effects on local skin blood flow. There were no significant differences between blood flow during compression and at baseline. Maxillofacial silicone elastomer was colored intrinsically with conventional color pigments: a control group containing only conventional pigments was compared to two test groups with 0.2 wt% and 0.6 wt% thermochromic pigment added. The color of the material was measured with a spectrophotometer in room temperature and after storage in a freezer. The color stability of the maxillofacial silicone elastomer colored with thermo¬chromic pigment was evaluated by artificial aging. The color dif¬ference of the L* (lightness) and a* values (redness), comparing color after the samples were stored at room temperature and in a freezer (-19°C), was statistically significant for both 0.2 wt% and 0.6 wt% thermo¬chromic pigment groups. The differences in the b* values (yellowness) were statistically significant for the 0.6 wt% group. Exposure to ultraviolet (UV) radiation led to visually noticeable and statistically signifi¬cant color changes (ΔE) in all color values in both test groups. The specimens containing thermochromic pigment were very sensitive to UV radiation. In conclusion, a framework of fiber-reinforced composite can successfully be bonded to maxillofacial silicone elastomer, and a framework beam, compressing the facial skin, did not remarkably alter the skin blood flow on healthy, young adults. The thermochromic pigment showed color change in maxillofacial silicone elastomer. However, artificial aging showed that it was too sensitive to UV radiation to be used, as such, in maxillofacial prostheses.

Multiple sclerosis and pregnancy: clinical and immunological aspects

Background: Multiple Sclerosis (MS) is an autoimmune disease of the central nervous system that affects most commonly young women in their childbearing age. Previous studies have shown that MS relapse rate usually reduces during pregnancy and increases again after delivery. Patients with MS and their treating physicians are interested to know more about the risks the disease can cause to pregnancy and how pregnancy affects the disease. The reasons for increased relapse rate after delivery are not entirely clear, but loss of pregnancy related immune tolerance and changes in the hormonal status at the time of delivery seem to be of relevance. Aims and methods: The aims of this study were to follow the natural course of MS during and after pregnancy, evaluate pregnancy related risks among MS patients, follow the inflammatory response of MS patients during and after pregnancy and clarify the risk of relevant co-morbidities known to affect other autoimmune diseases after pregnancy and compare these results to healthy controls. This study was a part of a prospective nation-wide follow-up study of 60 Finnish MS patients. All eligible MS patients were enrolled in the study during the years 2003-2005. A prospective followup continued from early pregnancy until six months postpartum. MS relapses, EDSS scores and obstetric details were recorded. Blood samples were obtained from the patients at early, middle, and late pregnancy, after delivery and one month, three months and six months postpartum. Results: MS patients were no more likely to experience pregnancy or delivery complications than the Finnish mothers in general. The need of instrumental assistance, however, was higher among mothers with MS. Disease activity followed the course seen in previous studies. The majority of mothers (90.2%) breastfed their babies. Contrary to previous results, breastfeeding did not protect MS patients from disease worsening after delivery in present study. Mothers with active pre-pregnancy disease chose to breastfeed less frequently and started medication instead. MS patients presented with higher prevalence of elevated thyroid autoantibodies postpartum than healthy controls, but the rate of thyroid hormonal dysfunction was similar as that of healthy controls. The mode of delivery nor the higher rate of tissue damage assessed with C-reactive protein concentration were not predictive of postpartum relapses. The prevalence of gestational diabetes was slightly higher among mothers with MS compared to Finnish mothers in general, but postpartum depression was observed in similar rates. MS patients presented with significantly lower serum concentrations of vitamin D during pregnancy and postpartum than healthy controls. Conclusions: Childbearing can be regarded as safe for mothers with MS as it is for healthy mothers in general. Breastfeeding can be recommended, but it should be done only after careful evaluation of the individual risk for postpartum disease activation. Considering MS patients tend to develop thyroid antibody positivity after delivery more often than healthy controls and that certain treatments can predispose MS patients to thyroid hormonal dysfunction, we recommend MS mothers to be screened for thyroid abnormalities during pregnancy and after delivery. Increased risk for gestational diabetes should be kept in mind when following MS mothers and glucose tolerance test in early pregnancy should be considered. Adequate vitamin D supplementation is essential for MS mothers also during pregnancy and postpartum period.

Toward including the effect of manufacturing processes in the pre-estimated losses of the switched reluctance motor

The estimation of losses plays a key role in the process of building any electrical machine. How to estimate those losses while designing any machine; by obtaining the characteristic of the electrical steel from the catalogue and calculate the losses. However, this way is inaccurate since the electrical steel performs several manufacturing processes during the process of building any machine, which affects directly the magnetic property of the electrical steel and accordingly the characteristic of the electrical steel will be affected. That means the B–H curve of the steel that was obtained from the catalogue will be changed. Moreover, during loading and rotating the machine, some important changes occur to the B–H characteristic of the electrical steel such as the stress on the laminated iron. Accordingly, the pre-estimated losses are completely far from the actual losses because they were estimated based on the data of the electrical steel obtained from the catalogue. So in order to estimate the losses precisely significant factors of the manufacturing processes must be included. The paper introduces the systematic estimation of the losses including the effect of one of the manufacturing factors. Similarly, any other manufacturing factor can be included in the pre-designed losses estimations.