Kumppanuus on tiiviimpää kuin yhteistyö : Maahanmuuttajataustaisten vanhempien näkemyksiä kasvatuskumppanuudesta

The main idea of this study was to find out how immigrants understand and define successful co-operation and professional partnership in early childhood education. Another target of this research was to think over how the parents see professional partnership from their viewpoint, and how willing / ready the they are in engaging in the professional partnership with the day care personnel. The theoretical part of this research is based on theories of immigration and theories of it s different forms, theories of cultural varieties and theory of modernizing co-operation through using professional partnership. Also guidelines and policies for day care and early childhood education play a part in the theory section. Theory part is written to support research problems. The research method used in this study is peer interview. The interviewed are both immigrants and customers of day care services. The data collected is comprised of materials from peer interviews and personal background information. The interviewed were of Somalia and Russian ethnic groups. Interview were carried out in each group in the participants own mother tongue. These peer interviews showed that parents were interested and willing to discuss professional partnership. From this research one can conclude that the term professional partnership is seen as a complex term, and as a term difficult to understand. From the results it is seen that quite often the principles of professional partnership are not carried out in practise. According to the material gathered, the parents feel that lack of common language and prejudice against immigrants effectively prevents the professional partnership from being formed. The cultural differences can become challenging in a professional partnership. Based on this research, one can conclude that when different cultures meet, there has to be mutual will to understand and to be understood in order to make sure that the children s development, both educational and physical, is supported in a best possible way.

Pyhä Kolminaisuus vai pilven reunalla istuva partasuu? : Jumalakuva evankelisluterilaisissa ja ortodoksissa 1.–4.-luokan uskonnon oppikirjoissa 1970–80- ja 2000-luvuilla

A concept of god is a wholeness that an individual experiences as God. The Christian concept of god is based on triune God: Father, Son, and the Holy Spirit. The concept of god is examined in different kinds of contexts particularly between the 1940's and the 1970's. Many researches of school books have widely been made in Finland, but, however, only a few from the point of view of the concept of god. Considering this, the concept of god in the school books of Evangelical Lutheran and Orthodox religion from first to fourth grade in 1970–80 and 2000 is examined in this survey. Additionally, the concept of god in curricula between years 1970 and 2004 is studied. The perspective on the concept of god is the change in the course of time and denominational emphasis. As a first hypothesis, God the Father is represented in books in 21st century as a kind and loving figure. As a second hypothesis, the Trinity and the Holy Spirit get more space in Orthodox books comparing with the Lutheran books. Twelve school books of Evangelical Lutheran and Orthodox religion from first to fourth grade were used as a research material. The books were from four different series between the years 1978 and 2005. Teacher's guidebooks and student's exercise books were left outside of this survey. The research material was analyzed by using abductive content analysis and methodological triangulation. This study included both qualitative and quantitative aspects. The classification system which defined the classifying of concept of god from the research material was consisted of the basis of research material, former reseach, and subtext of used theories. The number of mentions in concept of god was higher in books from the 21st century. In Lutheran books, the change was seen as a growth of the category of God the Father. In Orthodox books, the trend was opposite: the category of Jesus the Son had grown. Differing from the presupposition, the features of loving God in new books had less emphasis than in older books in both churces. The mentions of the Holy Spirit and Trinity were marginal. In the Orthodox books, the categories were bigger, as it was presupposed. It could be seen, that the books confirmed the legalistic period of the concept of god on 3rd and 4th grades. The mentions of concept of god in curriculas have diminished and generalized. The diminution was seen most radically in the curriculum from the year 1994. The results tell something about social changes and views of innovation in curricula. In books the change was not perceived that bright. The idea of the concept of god getting shrank and decreased during the time can be refused.

"Monesti on tullut ajateltua, että ihana, kamala kakara!" : Huomioidaanko päiväkodissa kansainvälisesti adoptoituun lapseen ja adoptioon liittyviä erityispiirteitä?

The purpose of this study was to examine the conceptions adoptive parents and kindergarten teachers have of adopted children in day care. Earlier Finnish research concerning international adoption has discussed adoption, adopted children and adoptive parents from the point of view of identity, racism and school. There has hardly been any research in Finland concerning adoption from the point of view of day care. The study focuses on how the special characteristics of adopted children are taken into consideration in day care. The ecological theory, in which a child's growth and learning environments are studied as part of the broader environment, provided the theoretical framework for the study. The study was based also on a second theory: intercultural competence or the capacity to interact with different people taking into consideration their individual characteristics and situations so that one understands and is understood. The first research problem consisted of describing the conceptions adoptive parents and day care teachers have of the special characteristics of adopted children. The second research problem was to examine adopted parents' expectations of kindergarten and of kindergarten teachers. The third research problem was to find out what kind of support day care teachers think they need when working with adopted children. The study focused on 20 adoptive parents and 15 kindergarten teachers. Research material was collected in the form of essay writings amounting to a total of 73 pages. The respondents wrote about their experiences with the help of a supporting questionnaire. The research method was qualitative and narrative. The results of the study show that adoptive parents have similar conceptions of adopted children's special characteristics concerning their character, social competence, adaptation and appearance. Adoptive parents had a better understanding of the dynamics of attachment than kindergarten teachers, in this study. When describing the special characters of adopted children, the teachers regarded adopted children in particular as needing special support. According to the results of the study, adoptive parents feel adoption matters and adoptive parenthood are something quite new and bewildering to day care teachers. Adoptive parents did not feel they got any support from the kindergarten in their parenthood. Adoptive parents regarded as particularly important the start of day care and the familiarisation process during which adopted children need time and special support due to earlier experiences of separation and abandonment. The findings of the study show that kindergarten teachers have little knowledge of adoption and the significance of adoption for a child's growth and development. Kindergarten teachers felt at a loss in dealing with adoption issues and clearly need additional support in the matter.

"Sitte se menee koulus" : Eri kieli- ja kulttuuritaustaisen lapsen suomen kielen taito esiopetuksen päättövaiheessa

A child learns new things, creates social relationships and participates in play with the help of language. How can a child overcome these challenges if the surrounding language is not his mother tongue? The objective of learning a new language in the Pre-school education is an active bilingualism in all fields of the language. Theoretical context of the research rises from bilingualism, learning a language, language skills and evaluating them. Object of the research was to understand language skills of a child from a different linguistic and cultural background in the final stage of Pre-school education and to clarify how learning Finnish was supported during the Pre-school year. Answers to the research issues will be searched with the following questions: 1) What kind of language skills does a child from a different linguistic and cultural backgrounds have at the final stage of Pre-school education?, 1.1) What kind of listening comprehension skills?, 1.2) What kind of speech and vocabulary skills?, 1.3) What kind of structural skills?, 2) What kind of individual differences are there in language skills of children from different linguistic and cultural backgrounds?, and 3) How has a child from a different linguistic and cultural background been supported in learning Finnish during the Pre-school education? The view of language skills in this research is holistic even though it will be analysed in separate fields. The aim of this research is to form an overall impression of Finnish skills of the children participating in the research. Eight Pre-school-aged children with different linguistic and cultural backgrounds and their kindergarten teachers participated in this research. The children had taken part in Finnish activities for about three years. The research material consists of the test series (KITA), which evaluate children’s language skills – and of the questionnaire to the kindergarten teachers. The purpose of the questionnaire was to provide additional information on children’s language skills in Pre-school teaching situations and on supporting Finnish in Pre-school education. This research is qualitative and processing of the material is based on content analysis. According to the kindergarten teachers, the children’s social language skills were sufficient to cope in everyday life but children needed assistance with longer instructions. The same phenomenon could also be seen with the KITA tests – in which long and abstract instructions turned out to be difficult. Individual differences of the children were perceived in productivity skills, which were realised in fluent or influent speech. The children were supported in learning Finnish individually, in small-groups and in the activities of a whole group. ‘Finnish as the second language’ small-groups were the most common form of support in learning the language. The support at understanding activities was emphasized in whole group situations as well as in individual situations while assisting the child’s language skills. Generally, the children’s language skills were in the same level with developing basic language skills. The data of this research help to understand children’s language skills after three years of adopting Finnish. The results can be utilised in planning and evaluation of teaching another language.

Ekologisuus saaristolaiskäsityössä : Käsityöläisten luomia merkityksiä etsimässä

Tutkimuksessa etsittiin vastauksia kysymykseen, miten saariston tekstiilikäsityöläinen tavoittelee ekologista kestävyyttä työssään. Mitä ekologisuus hänelle merkitsee ja miten se ilmenee hänen töissään? Kertojana on sekä tuote että tekijä. Tutkimus on fenomenologisesti orientoitunut ja vastauksia tutkimuskysymyksiin haettiin teorian ja aineiston vuoropuhelulla . Analyysimenetelmänä käytettiin sisällön analyysia. Analysoitava aineisto on hankittu haastattelemalla yhdeksää käsityöläistä, jotka asuvat Lounais-Suomen, Ahvenanmaan ja Tukholman alueen saaristoissa. Tutkimuksen teoreettisissa lähtökohdissa on tarkasteltu kestävän kehityksen ja saariston käsityön suhdetta. Kulttuuriseen, sosiaaliseen, taloudelliseen ja tuotannolliseen kestävyyteen panostamalla pyritään ekologiseen kestävyyteen. Käsityöläisen arvot, taidot ja tiedot vaikuttavat kehityksen eri osa-alueilla. Käsityöläisen toimintaympäristönä oli saaristo, sen luonto ja ihmisen aikaansaama kulttuuri. Tutkimuksessa selvitettiin sitä, miten saaristo ja saaristolaisuus vaikuttivat käsityöläisen tapaan toimia ja kertoa tekemistään tuotteista. Ekologisuus saaristolaiskäsityössä ilmeni monin tavoin. Kulttuurinen ja sosiaalinen kestävyys toteutuivat taloudellista ja tuotannollista kestävyyttä paremmin. Koulutuksen koettiin olevan paras keino saavuttaa välitavoitteita kestävässä kehityksessä. Käsityöläisyys nähtiin osana saaristolaiskulttuuria ja verkostoituminen harvaan asutulla seudulla koettiin tärkeäksi. Tutkimuksessa pohdittiin, onko ekologisuus materiaalin alkuperään, työtapaan vai tuotteen käyttöikään ja hävitykseen liittyvä asia. Ekologisuus yhdistettiin usein käsityön materiaaliin ja sen tuotantotapoihin. Arvot konkretisoituvat käsityöläisen puhuessa perheestään ja kasvamisesta käsityöläisyyteen. Ekologiseen käsityöhön panostaminen on myös osa käsityöläisen kasvuprosessia. Ekologiseen kestävyyteen pyrkiminen käsityössä herätti myös ristiriitaisia tunteita. Käsityöläisyys on elinkeino markkinoilla, joilla globaali kauppa määrittelee säännöt. Merkitseekö ekologiseen kestävyyteen pyrkiminen kurkottamista kohti totuutta? Avainsanat: ekologinen kestävyys, kestävä kehitys, arvot, käsityöläisyys, käsityö, saaristo saaristolaisuus

Automaatioteknologian opetus kuvakepohjaisella ohjelmointikielellä : Teknologiakasvatuksen opetuskokeilu kolmessa eri käyttöympäristössä

Tutkimus kuuluu Helsingin yliopiston opettajankoulutuslaitoksen luonnontieteen ja teknologian opetusta ja opetusvälineitä kehittävään LUONTI-projektiin. Tutkimuksen tarkoituksena on teknologiakasvatukseen liittyvän käsitteistön selkiyttäminen ja projektissa kehitetyn laitteiston, Empirica Controlin, käyttöönotto ja sen tutkiminen. Teoreettisessa taustassa tarkastellaan teknologiaa ja teknologiakasvatusta oppivelvollisuuskoulun näkökulmasta. Erilaisia teknologiamäärittelyjä ja ajatuksia teknologian olemuksesta verrataan tutkimuksessa kehitetyillä malleilla. Teknologia on luonteeltaan integroiva aihepiiri, jolle on ainakin tässä tutkimuksessa esitetyn teorian valossa vaikea määritellä omaa tiedonalaa ja siten luontevaa paikkaa omana oppiaineenaan. Avoimessa oppimisympäristössä tapahtuvaa kognitiivisen teorian mukaista oppimista on hahmoteltu muokkaamalla Lehtisen (1988) esittämää mallia. Aikaisempien tutkimus- ja kokeiluraporttien perusteella määritellään kolme luovaa ongelmanratkaisua ja avointa oppimisympäristöä hyödyntävää työtapaa: mallintava menetelmä, ongelmanratkaisu ja vapaa kokeilu. Empirica Controlia verrataan tekstipohjaiseen Logoon ja muihin markkinoilla oleviin laitteistoihin sekä tarkastellaan sen ominaisuuksia didaktiikan ja konstruktivistisen oppimisteorian näkökulmasta. Tutkimuksen empiirinen osuus koostuu kolmesta opetuskokeilusta. Laajin kokeilu järjestettiin kahdella helsinkiläisellä peruskoulun ala-asteen 2. luokalla. Menetelmällisenä viitekehyksenä oli neljä sykliä käsittävä opetus- ja arviointikäytäntöjen kehittämiseen pyrkivä toimintatutkimus, jossa jokainen sykli pitää sisällään kvantitatiivisesti suoritetun oppimisen tarkastelun. Tiedonhankintamenetelminä käytettiin oppilaiden itsearviointia, erilaisia haastatteluja ja ääninauhan tukemaan strukturoitua päiväkirjaa pyrkien menetelmälliseen triangulaatioon. Näitä tuloksia varmennettiin kahdella lyhyemmällä opetuskokeilulla, joista toisessa tutkittavat olivat viidesluokkalaisia ja toisessa luokan- ja lastentarhanopettajiksi opiskelevia. Tutkimus tuotti kokemuksia Empirica Controlin opetuskäytöstä sekä laitteiston kehittämisehdotuksia. Tulosten mukaan oppilailla oli työskentelyn vaatiman teknologiaan, tietotekniikkaan ja rakentamisee nliittyvät perusvalmiudet. He kokivat työskentelyn positiivisena ja oppivat käyttämään ohjelmointikielen yksinkertaisimpia käskyjä. Lyhyemmät opetuskokeilut antoivat samansuuntaisia tuloksia. Teknologian oppimista tutkittiin automaatioteknologisten laitteiden toiminnasta annettujen selitysten kautta. Selityksissä havaittiin vain hienoista paranemista. Avainsanat: teknologiakasvatus, konstruktivismi, avoin oppimisympäristö, ryhmätyö, tietokoneavusteinen opetus,triangulaatio Keywords: technology education, constructivism, open learning environment, groupwork, computer-aided instruction,triangulation

Neural stem cell characteristics affected by oncogenic pathways and in a human motoneuron disease

Neural stem cell characteristics affected by oncogenic pathways and in a human motoneuron disease Stem cells provide the self-renewing cell pool for developing or regenerating organs. The mechanisms underlying the decisions of a stem or progenitor cell to either self-renew and maintain multipotentiality or alternatively to differentiate are incompletely understood. In this thesis work, I have approached this question by investigating the role of the proto-oncogene Myc in the regulatory functions of neural progenitor cell (NPC) self-renewal, proliferation and differentiation. By using a retroviral transduction technique to create overexpression models in embryonic NPCs cultured as neurospheres, I show that activated levels of Myc increase NPC self-renewal. Furthermore, several mechanisms that regulate the activity of Myc were identified. Myc induced self-renewal is signalled through binding to the transcription factor Miz-1 as shown by the inhibited capacity of a Myc mutant (MycV394D), deficient in binding to Miz-1, to increase self-renewal in NPCs. Furthermore, overexpression of the newly identified proto-oncogene CIP2A recapitulates the effects of Myc overexpression in NPCs. Also the expression levels and in vivo expression patterns of Myc and CIP2A were linked together. CIP2A stabilizes Myc protein levels in several cancer types by inhibiting its degradation and our results suggest the same function for CIP2A in NPCs. Our results also support the conception of self-renewal and proliferation being two separately regulated cellular functions. Finally, I suggest that Myc regulates NPC self-renewal by influencing the way stem and progenitor cells react to the environmental cues that normally dictate the cellular identity of tissues containing self-renewing cells. Neurosphere cultures were also utilised in order to characterise functional defects in a human disease. Neural stem cell cultures obtained post-mortem from foetuses of lethal congenital contracture syndrome (LCCS) were used to reveal possible cell autonomous differentiation defects of patient NPCs. However, LCCS derived NPCs were able to differentiate normally in vitro although several transcriptional differences were identified by using microarray analysis. Proliferation rate of the patient NPCs was also increased as compared to NPCs of age-matched control foetuses.

Stem Cell Markers in Cancer: Do They Have Clinical Significance?

In cancer, a subpopulation of malignant cells expresses markers of normal stem cells. These cells have the potential of initiating tumor growth and therefore also tumor recurrence. Thus, these cells are called cancer stem cells. A myriad of markers have been applied to identify these cells, but no single marker can be found exclusively in cancer stem cells. In many types of cancer, clinical recurrence and tumor progression are the main causes of mortality, despite intense oncological treatment. It has been proposed that the presence of cancer stem cells causes this resistance to therapy. The scope of this thesis is to investigate the role of stem cell markers and genes in the clinical setting. Especially, the aim was to elucidate the clinical significance of stem cell markers as novel prognostic and diagnostic tools in cancer. Tumor biopsy material from central nervous system tumors (oligodendroglioma, astrocytoma and glioblatoma), neural crest derived tumors (pheochromocytomas) and oral carcinoma was screened for stem cell markers. Initially, 15 stem cell markers were screened in a test series of gliomas. The markers applied for expanded tumor analyses (in 305 cases of glioma, 42 cases of pheochromocytoma, and 73 cases of oral carcinoma) were BMI-1, Snail, p16, mdm2, and c-Myc. Data on marker expression was compared with clinical and pathological parameters. In gliomas, BMI-1 expression was found in nearly all tumors analyzed, but the frequency of BMI-1 expressing cells was highly variable, ranging from 1 to 100%. In oligodendroglioma, BMI-1 expression was identified as a prognostic marker independent of tumor grade and clinical parameters. In pheochromocytoma, Snail expression was shown to distinguish between the metastatic and non-metastatic forms of the tumor. Snail expression was seen only in metastatic tumors, whereas non-metastatic tumors did not commonly express Snail. Finally, in oral carcinoma, BMI-1 expression was seen in roughly 80% of tumors, and Snail expression was high or very high in all cases. The lack of BMI-1 expression was associated with early relapse in oral carcinoma.

Androgen receptor-dependent and independent functions of ARIP4

Androgen receptor (AR) is necessary for normal male phenotype development and essential for spermatogenesis. AR is a classical steroid receptor mediating actions of male sex steroids testosterone and 5-alpha-dihydrotestosterone. Numerous coregulators interact with the receptor and regulate AR activity on target genes. This study deals with the characterization of androgen receptor-interacting protein 4 (ARIP4). ARIP4 binds DNA, interacts with AR in vitro and in cultured yeast and mammalian cells, and modulates AR-dependent transactivation. ARIP4 is an active DNA-dependent ATPase, and this enzymatic activity is essential for the ability of ARIP4 to modulate AR function. On the basis of sequence homology in its ATPase domain, ARIP4 belongs to the SNF2 family of proteins involved in chromatin remodeling, DNA repair, and homologous recombination. Similar to its closest homologs ATRX and Rad54, ARIP4 does not seem to be a classical chromatin remodeling protein in that it does not appear to form large protein complexes in vivo or remodel mononucleosomes in vitro. However, ARIP4 is able to generate superhelical torsion on linear DNA fragments. ARIP4 is covalently modified by SUMO-1, and mutation of six potential SUMO attachment sites abolishes the ability of ARIP4 to bind DNA, hydrolyze ATP, and activate AR function. ARIP4 expression starts in early embryonic development. In mouse embryo ARIP4 is present mainly in the neural tube and limb buds. In adult mouse tissues ARIP4 expression is virtually ubiquitous. In mouse testis ARIP4 is expressed in the nuclei of Sertoli cells in a stage-dependent manner. ARIP4 is also present in the nuclei of Leydig cells, spermatogonia, pachytene and diplotene spermatocytes. Testicular expression pattern of ARIP4 does not differ significantly in wild-type, FSHRKO, and LuRKO mice. In the testis of hpg mice, ARIP4 is found mainly in interstitial cells and has very low, if any, expression in Sertoli and germ cells. Heterozygous Arip4+/ mice are fertile and appear normal; however, they are haploinsufficient with regard to androgen action in Sertoli cells. In contrast, Arip4 / embryos are not viable. They have significantly reduced body size at E9.5 and die by E11.5. Compared to wild-type littermates, Arip4 / embryos possess a higher percentage of apoptotic cells at E9.5 and E10.5. Fibroblasts derived from Arip4 / embryos cease growing after 2-3 passages and exhibit a significantly increased apoptosis and decreased proliferation rate than cells from wild-type embryos. Our findings demonstrate that ARIP4 plays an essential role in mouse embryonic development. In addition, testicular expression and AR coregulatory activity of ARIP4 suggest a role of ARIP4-AR interaction in the somatic cells of the testis.

Milk casein-derived tripeptides : A special focus on blood pressure and vascular function

Increased consumption of low-fat milk products is inversely associated with the risk of hypertension. The beneficial effect of milk on blood pressure is attributed to high calcium and potassium content but also to specific peptide sequences, which are cleaved from milk protein during gastrointestinal digestion, fermentation of milk with proteolytic starter cultures or enzymatic hydrolysis. Milk products fermented with Lactobacillus helveticus contain casein-derived tripeptides isoleucine-proline-proline (Ile-Pro-Pro) and valine-proline-proline (Val-Pro-Pro), which have been shown to possess antihypertensive effects in humans and in experimental animals. The aim of the present series of studies was to investigate the effects of tripeptides Ile-Pro-Pro and Val-Pro-Pro or fermented milk products containing them on vascular function and blood pressure and to elucidate the mechanisms behind them by using different experimental models of hypertension. Another aim was to characterize the acute effects of tripeptides on blood pressure and arterial stiffness in mildly hypertensive humans. Ile-Pro-Pro and Val-Pro-Pro or fermented milk products containing them attenuated the development of hypertension in two experimental models of hypertension, spontaneously hypertensive rat (SHR) and type 2 diabetic Goto-Kakizaki (GK) rat fed with high-salt diet. Significant differences in systolic blood pressure (SBP) were seen after 8 weeks treatment with tripeptide-containing products compared to control product. Plant sterols did not enhance this effect. Two differently produced tripeptide powders produced a similar attenuating effect on SBP in SHR. In mildly hypertensive subjects, a single administration of tripeptide- and plant sterol-containing fermented milk product decreased both SBP and diastolic blood pressure (DBP) over a period of 8 hours. Protective effect of tripeptides Ile-Pro-Pro and Val-Pro-Pro and fermented milk products containing them on vascular function was demonstrated in in vitro studies and long-term experimental studies. The effect was shown to be endothelium-dependent and possibly involving endothelium-derived hyperpolarizing factor (EDHF). In the clinical study, single administration of tripeptide-containing fermented milk product did not affect measures of arterial stiffness. Long-term treatment with fermented milk product containing Ile-Pro-Pro and Val-Pro-Pro inhibited angiotensin-converting enzyme (ACE) and decreased aldosterone levels thus showing beneficial effects on the renin-angiotensin system (RAS) in SHR and GK. No changes in the components of RAS were observed by the single administration of the same product in mildly hypertensive subjects. Increased levels of cGMP, NOx and citrulline suggest increased nitric oxide (NO) production by the tripeptides. Taken together, Ile-Pro-Pro and Val-Pro-Pro -containing products attenuate the development of hypertension after long-term treatment in experimental models of hypertension and possess an acute antihypertensive effect in mildly hypertensive subjects. In addition, these tripeptides show endothelium-mediated beneficial effects on vascular function. Attenuation of blood pressure increase by the tripeptides in experimental animals involves RAS, but its role in the antihypertensive effect in humans remains to be elucidated.

Cellular Cholesterol Accumulation and Egress from Endosomal Compartments

One of the most important factors determining the development of atherosclerosis is the amount of LDL particles in the circulation. In general, LDL particles are clinically regarded as “bad cholesterol” since these particles get entrapped within the vascular wall, leading to atherosclerosis. Circulating HDL particles are conversely regarded as “good cholesterol” because of their ability to transport cholesterol from peripheral tissues to the liver for secretion as bile salts. Once inside the artery wall LDL particles are engulfed by macrophages, resulting in macrophage foam cells. If the macrophage foam cells are not able to efflux the cholesterol back into the bloodstream, the excessive cholesterol ultimately leads to cell death, and the deposition of cellular debris within the atherosclerotic lesion. The cells ability to secrete cholesterol is mainly dependent on the ABCA1 transporter (ATP-binding cassette transporter A1) which transfers cellular cholesterol to extracellular apoA-I (apolipoprotein A-I) particles, leading to the generation of nascent HDL particles. The process of atherosclerotic plaque development is therefore to a large extent a cellular one, in which the capacity of the macrophages in handling the excessive cholesterol load determines the progression of lesion development. In this work we have studied the cellular mechanisms that regulate the trafficking of LDL-derived cholesterol from endosomal compartments to other parts of the cell. As a basis for the study we have utilized cells from patients with Niemann-Pick type C disease, a genetic disorder resulting from mutations in the NPC1 and NPC2 genes. In these cells, cholesterol is entrapped within the endosomal compartment, and is not available for efflux. By identifying proteins that bypass the cholesterol trafficking defect, we were able to identify the small GTPase Rab8 as an important protein involved in ABCA1 dependent cholesterol efflux. In the study, we show that Rab8 regulates cholesterol efflux in human macrophages by facilitating intracellular cholesterol transport, as well as by regulating the plasma membrane availability of ABCA1. Collectively, these results give new insight in to atherosclerotic lesion development and intracellular cholesterol processing.

Molecular Mechanisms of Androgen Receptor Interactions

The androgen receptor (AR) mediates the effects of the male sex-steroid hormones (androgens), testosterone and 5?-dihydrotestosterone. Androgens are critical in the development and maintenance of male sexual characteristics. AR is a member of the steroid receptor ligand-inducible transcription factor family. The steroid receptor family is a subgroup of the nuclear receptor superfamily that also includes receptors for the active forms of vitamin A, vitamin D3, and thyroid hormones. Like all nuclear receptors, AR has a conserved modular structure consisting of a non-conserved amino-terminal domain (NTD), containing the intrinsic activation function 1, a highly conserved DNA-binding domain, and a conserved ligand-binding domain (LBD) that harbors the activation function 2. Each of these domains plays an important role in receptor function and signaling, either via intra- and inter-receptor interactions, interactions with specific DNA sequences, termed hormone response elements, or via functional interactions with domain-specific proteins, termed coregulators (coactivators and corepressors). Upon binding androgens, AR acquires a new conformational state, translocates to the nucleus, binds to androgen response elements, homodimerizes and recruits sequence-specific coregulatory factors and the basal transcription machinery. This set of events is required to activate gene transcription (expression). Gene transcription is a strictly modulated process that governs cell growth, cell homeostasis, cell function and cell death. Disruptions of AR transcriptional activity caused by receptor mutations and/or altered coregulator interactions are linked to a wide spectrum of androgen insensitivity syndromes, and to the pathogenesis of prostate cancer (CaP). The treatment of CaP usually involves androgen depletion therapy (ADT). ADT achieves significant clinical responses during the early stages of the disease. However, under the selective pressure of androgen withdrawal, androgen-dependent CaP can progress to an androgen-independent CaP. Androgen-independent CaP is invariably a more aggressive and untreatable form of the disease. Advancing our understanding of the molecular mechanisms behind the switch in androgen-dependency would improve our success of treating CaP and other AR related illnesses. This study evaluates how clinically identified AR mutations affect the receptor s transcriptional activity. We reveal that a potential molecular abnormality in androgen insensitivity syndrome and CaP patients is caused by disruptions of the important intra-receptor NTD/LBD interaction. We demonstrate that the same AR LBD mutations can also disrupt the recruitment of the p160 coactivator protein GRIP1. Our investigations reveal that 30% of patients with advanced, untreated local CaP have somatic mutations that may lead to increases in AR activity. We report that somatic mutations that activate AR may lead to early relapse in ADT. Our results demonstrate that the types of ADT a CaP patient receives may cause a clustering of mutations to a particular region of the receptor. Furthermore, the mutations that arise before and during ADT do not always result in a receptor that is more active, indicating that coregulator interactions play a pivotal role in the progression of androgen-independent CaP. To improve CaP therapy, it is necessary to identify critical coregulators of AR. We screened a HeLa cell cDNA library and identified small carboxyl-terminal domain phosphatase 2 (SCP2). SCP2 is a protein phosphatase that directly interacts with the AR NTD and represses AR activity. We demonstrated that reducing the endogenous cellular levels of SCP2 causes more AR to load on to the prostate specific antigen (PSA) gene promoter and enhancer regions. Additionally, under the same conditions, more RNA polymerase II was recruited to the PSA promoter region and overall there was an increase in androgen-dependent transcription of the PSA gene, revealing that SCP2 could play a role in the pathogenesis of CaP.

Self-reported bruxism : Associated factors among media personnel with or without irregular shift work

Tutkimuksen kohderyhmänä oli mediatyöntekijöitä, joiden toimenkuva on viime vuosina muuttunut yhä kuormittavammaksi epäsäännöllisen vuorotyön sekä jatkuvien teknisten, organisatoristen ja taloudellisten tekijöiden ristipaineessa. Väitöskirjatutkimus on osa laajempaa tutkimushanketta, joka suunniteltiin selvittämään epäsäännöllisen vuorotyön mahdollisia haittoja. Tutkimusta tukivat taloudellisesti Työsuojelurahasto ja Suomen Hammaslääkäriseura Apollonia sekä resurssipanostuksin Hammaslääketieteen laitos (HY), Työterveyslaitos ja Yleisradio Oy. Bruksismi on tahdosta riippumatonta hampaiden narskuttelua tai yhteenpuristamista. Hampaiden narskuttelu on rytmistä jaksoittain toistuvaa puremalihasten toimintaa, joka esiintyy nukkuessa -tavallisimmin kevyen unen ja havahtumisjaksojen yhteydessä. Valveilla ollessa bruksismi on terveillä ihmisillä lähinnä hampaiden yhteenpuristamista. Yleisen käsityksen mukaan toistuvaa unibruksismia esiintyy noin 10 %:lla ja valveilla tapahtuvaa hampaiden yhteenpuristamista noin 20 %:lla. Aiemmin bruksismi kuului kansainvälisen unihäiriöluokituksen (ICSD 1997) mukaan unen erityishäiriöihin, mutta tuorein luokitus (ICSD 2005) listaa sen unen liikehäiriöihin. Väitöstutkimuksen yleisenä tavoitteena oli kartoittaa koetun bruksismin ja uni- valvehäiriöiden yhteyttä. Tutkimus oli poikittainen vertailututkimus epäsäännöllistä vuorotyötä ja säännöllisiä päivävuoroja tekevien välillä. Mielenkiinto kohdistui myös bruksismin ja kasvojen alueen kivun mahdolliseen yhteyteen. Lisäksi tutkimuksessa selvitettiin joidenkin tunnetusti unen laatua huonontavien psykososiaalisten, neurologisten ja fysiologisten tekijöiden yhteyttä koettuun bruksismiin. Tutkimuksen kohderyhmän muodosti 750 Yleisradion epäsäännöllistä vuorotyötä tekevää työntekijää. Vertailuryhmänä käytettiin samansuuruista satunnaistetusti valittua kaltaistettua Yleisradion työntekijäjoukkoa, joka tekee samankaltaista työtä, mutta säännöllisenä päivätyönä. Kohderyhmälle lähetettiin kyselylomakkeet, jotka kartoittivat koetun bruksismin lisäksi mm. tutkittavien taustatiedot, yleisen terveydentilan, yleisiä koettuja stressioireita ja tuntemuksia, kipuoireita, sekä unen laatua. Lisäksi esitettiin jaksamista ja työympäristöä koskevia kysymyksiä. Kyselyyn vastasi kaikkiaan 874 henkilöä. Kokonaisvastausprosentti oli 58,3 % (53,7 % miehiä). Epäsäännöllistä vuorotyötä tekevien vastausprosentti oli 82,3 % ja säännöllistä päivätyötä tekevien ryhmässä 34,3 %. Työtehtävät sisälsivät ohjelmien toimitus- ja tuottamistyötä, teknistä tuotanto- ja tukityötä, sekä esimies- ja hallintotyötä. Miesten keski-ikä vuorotyöryhmässä oli 45,0 (± 10,6) vuotta ja naisten keski-ikä 42,6 (± 10,7) vuotta, vastaavat luvut päivätyötä tekeville olivat 47,4 (± 9,7) ja 45,5 (± 10,1) vuotta. Vuorotyötä tekevistä oli miehiä 56,6 %, päivätyöryhmässä miehien osuus oli 46,7 %. Usein koettua bruksismia havaittiin koko tutkimusjoukossa 10,6 %:lla. Bruksismin esiintyvyydessä ei ollut merkitsevää eroa epäsäännöllistä vuorotyötä ja päivätyötä tekevien välillä. Kun bruksismia ja stressiä arvioitiin suhteessa tyytyväisyyteen nykyiseen työaikamuotoon, molemmat olivat merkitsevästi vallitsevimpia niillä, jotka halusivat vaihtaa nykyistä työaikamuotoaan. Epäsäännöllistä vuorotyötä tekevät lisäksi ilmoittivat kokevansa enemmän stressiä kuin päivätyötä tekevät sekä olivat tyytymättömämpiä työaikamuotoonsa. Tutkittavista henkilöistä katkonaista unta esiintyi 43,6 %:lla sekä 36,2 % koki unensa virkistämättömäksi. Kasvokipua esiintyi 19,6 %:lla. Usein toistuva bruksaus sekä tyytymättömyys työaikamuotoon olivat erittäin merkitsevästi yhteydessä unihäiriöiden sekä riittämättömän unen oireiden kanssa. Bruksismi ja katkonainen uni osoittautuivat myös kasvokivun taustatekijöiksi. Tutkimus osoitti, että koetulla bruksismilla oli merkitsevä yhteys unihäiriöihin, kasvokipuun, koettuun stressiin ja ahdistuneisuuteen, nuorempaan ikään, runsaampiin hammaslääkäri- ja lääkärikäynteihin sekä siihen että oli tyytymätön työaikamuotoonsa (itse työaikamuoto ei ollut merkitsevä tekijä). Tutkimuksen yhtenä johtopäätöksenä todettiin, että koettu bruksismi voi terveillä työikäisillä henkilöillä olla osa stressaavaa tilannetta ja siihen liittyvää käyttäytymistä. Tämän tiedostaminen terveydenhuollossa voisi olla hyödyllistä.

The influence of HIV infection to the periodontium; a clinical, microbiological, and enzymological study

The main targets of human immunodeficiency virus (HIV) are CD4 receptors of CD4+ lymphocytes and many other cells such as monocytes/macrophages, megakaryocytes, peripheral blood dendritic cells, follicular dendritic cells (DC), epidermal Langerhans cells, and astrocytes. Infection and killing of CD4+ lymphocytes or false reaction of the body to HIV infection and the spontaneous apoptosis of CD4+ lymphocytes decrease CD4+ lymphocyte counts leading to immunosuppression, further disease progression, and appearance of opportunistic infections and malignancies. Oral manifestations are considered to be among the first signs of HIV infection. Enhanced degradation of extracellular matrix and basement membrane components in oral diseases including periodontitis is caused by Zn-dependent enzymes called matrix metalloproteinases (MMPs). The levels and degrees of activation of MMP-1, -2, -3, -7, -8, -9, -25, -26, tissue inhibitors of MMPs (TIMP)-1 and -2, and myeloperoxidase (MPO) and collagenolytic/gelatinolytic activities, and also Ig A, -G, and -M, total protein, and albumin levels in a two-year follow-up were studied from salivary samples. The expression of MMP-7, -8, -9, -25, and -26 immunoreactivities in gingival tissue specimens were studied. Healthy HIV-negative subjects served as controls. All studied clinical periodontal parameters and microbiological evaluation of the periodontopathogens showed that periodontal health of the HIV-positive patients was moderately decreased in comparison to the healthy controls. The levels of Candida in the periodontal pockets and salivary MPO increased with the severity of HIV infection. Immunoreactivities and levels of MMPs and TIMPs, and MMP activities (collagenase, gelatinase) were enhanced in the HIV-positive patient salivary samples relative to the healthy controls regardless of the phase of HIV infection. However, these parameters did not reflect periodontal status in a similar way as in the generally healthy periodontitis patients. Salivary total protein, albumin, IgA, -G, and -M levels were significantly higher in all phases of HIV infection compared to the controls, and salivary total protein, IgG and IgM levels remained higher after two years follow-up, partly correlating with the disease progression and which may reflect the leakage of serum components into the mouth and thus a decreased mucosal barrier. Salivary analyses of MMPs and TIMPs with immunohistochemical analyses showed that HIV infection could predispose to periodontal destruction when compared with healthy controls or the body s defence reactions associated with HIV infection may have been reflected or mediated by MMPs.

Toxicity of dioxin to developing teeth and salivary glands : An experimental study

Dioxins are ubiquitous environmental poisons having unequivocal adverse health effects on various species. The majority of their effects are thought to be mediated by the aryl hydrocarbon receptor (AhR). Developing human teeth may be sensitive to dioxins and the most toxic dioxin congener, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), is developmentally toxic to rodent teeth. Mechanisms of TCDD toxicity can be studied only experimentally. The aim of the present thesis work was to delineate morphological end points of developmental toxicity of TCDD in rat and mouse teeth and salivary glands in vivo and in vitro and to characterize their cellular and molecular background. Mouse embryonic teeth and submandibular gland explants were grown in organ culture without/with TCDD at various concentrations, examined stereomicroscopically and processed for histological examination. The effects of TCDD on cellular mechanisms essential for organogenesis were investigated. The expression of various genes eliciting the response to TCDD exposure or involved in tooth and salivary gland development was studied at the mRNA and/or protein levels by in situ hybridization and immunohistochemistry. Association of the dental effects of TCDD with the resistance of a rat strain to TCDD acute lethality was analyzed in two lactationally exposed rat strains. The effect of TCDD on rat molar tooth mineralization was studied in tissue sections. TCDD dose- and developmental stage-dependently interfered with tooth formation. TCDD prevented early mouse molar tooth morphogenesis and altered cuspal morphology by enhancing programmend cell death, or apoptosis, in dental epithelial cells programmed to undergo apotosis. Cell proliferation was not affected. TCDD impaired mineralization of rat molar dental matrices, possibly by specifically reducing the expression of the mineralization-related dentin sialophosphoprotein gene shown in cultured mouse teeth. The impaired mineralization of rat teeth was accompanied by decreased expression of AhR and the TCDD-inducible xenobiotic-metabolozing enzyme P4501 A1 (CYP1A1), suggesting mediation of the TCDD effect by the AhR pathway. The severe interference by TCDD with rat incisor formation was independent of the genotypic variation of AhR determining the resistance of a rat strain to TCDD acute lethality. The impairment by TCDD of mouse submandibular gland branching morphogenesis was associated with CYP1A1 induction and involved blockage of EGF receptor signalling. In conclusion, TCDD exposure is likely to have activated the AhR pathway in target organs with the consequent activation of other signalling pathways involving developmentally regulated genes. The resultant phenotype is organ specific and modified by epithelial-mesenchymal interactions and dependent on dose as well as the stage of organogenesis at the time of TCDD exposure. Teeth appear to be responsive to TCDD exposure throughout their development.