286 resultados para Myt
Resumo:
From the field to the academic sphere how teachers professional identities and roles have changed in post-war Finland This study explores teacher autobiographies. The span of the writings extends mainly from the Second World War to the new millennium. The autobiographers are mostly elementary and secondary school teachers in Finland, although there are a few who have worked in vocational schools, polytechnic institutes or one of the various adult education centres. The researcher is aware of the diversity among those educational institutions and their teachers, but wanted to concentrate on similarities rather than differences. The autobiographers have been explored with four different research questions in view. The first was to identify professional and personal elements and themes mentioned by teachers in writing about themselves. The second was to identify the factors that have affected those elements and themes. The third was to examine the kinds of literary forms teachers used in their autobiographies. The fourth was the most crucial and an endeavour to connect the previous questions: how teachers professional identities and roles have changed during the period studied. In the first five chapters the teachers voices come through clearly. Two of these chapters are organized in chronological order. The first is about childhood, youth and the time spent in school, the second deals with the years studying in university or teachers college and finally being recruited to the teachers. In these chapters the rural background of many teachers stands out, an issue that also emerged symbolically or de facto in the autobiographies. The chronological scheme changes to a thematic order, in which social matters (students, parents, colleagues) and teachers working circumstances are dealt with. Four selected autobiographies are examined closely. In these autobiographies five different types of teacher narratives can be identified. To begin with, teachers stressed their vocation, which is quite a normal work orientation for those working in the educational field. Others emphasised how they were looking for professional development; a few wrote about personal advancement as well. There are also narratives by teachers who simply drifted into the profession of teaching, while a few teachers felt unwelcome in their own schools. As for the changes that teachers have witnessed, there are also some themes that are widely shared. Most pointed out how the teacher has become more foster parent than educator, as real parents have withdrawn from their responsibilities of raising children. This theme was frequently broached, although attitude towards it and ways of handling the phenomenon differed substantially. Teachers also stressed how their profession has lost the aura and prestige it once had. At the same time teachers are being expected to collaborate more with their colleagues, which is not in line with the centuries-old tradition of working alone. Teachers seem to be in a state of flux, buffeted by elements of stability and change interacting simultaneously. Many teachers are demanding a re-examination of their working reality. Teachers long and intimate relationship with society and the state may be at a crossroads. Key words: teachers professional identity and role, autobiographical study, post-war Finland
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The purpose of this study is to determine what class teachers and special teachers emphasise in ethical consideration, in which situations they find that ethical difficulties arise and how they would overcome them. In additions, the study aims to describe the effects of ethical con-sideration on the teachers` work. The theoretical backround is based on theories concerning the ethics of the teacher and the literature associated with education and teaching. The empirical study was based on data obtained through questionnaires and interviews. The questionnaires were posted to 470 randomly-selected class teachers and special teachers; 298 of them (63%) completed and returned the questionnaire, and 19 teachers were inter-viewed. The results of the questionnaires and the interviews were examined crosswise with a mixed-methods procedure. The questionnaires were analysed by factor analysis. Those items which rose above the av-erage served as the foundation for the analysis. The questionnaires also included open ques-tions. These questions and the interviews were analysed with a content analysis method. Some principles of this method were combined with the results of the questionnaires to in-crease mutual understanding. In this study, the ethical consideration of the teachers was divided in to four notable parts: 1) moral obligations, 2) respect for the teaching stuff, 3) the demand for responsibility, and 4) dependence on the situation. These items were also notable both in situations that were ethi-cally difficult for teachers and in their solutions to these situations. It became evident that these situations were very common in everyday work and resulted from the character of the teachers´ work. This study showed that the teacher meets the pupils as a group and that the teacher must examine according to the circumstances the truth, individuality, special ar-rangements and co-operation between the school and the parents. The teachers` continuous lack of time limited the ethical consideration. It emerged that the teachers consider their work very multi-faceted and that the sense of obligation, power and responsibility was inevitably received emphasis. The consciousness of authority and the responsibilities associated with it seemed, however, to strengthen this ac-tion. The study showed that the teachers, especially the young female ones, long for more solidarity. Significantly, such experience does not eliminate the importance of ethical consid-eration; on the contrary, it deepens it. According to the results, creating conditions and cir-cumstances for the teachers that open co-operation is inevitable, and easy interaction will in-evitably be possible in the future. There was not observed any differences in ethical consideration between class teachers and special teachers. Therefore, the integration of the pupils to general teaching cannot be consid-ered questionable. Teachers´ answers suggested that ethical consideration improved the tolerance of stress, increased self-confidence and courage as well as belief in the future. The teachers considered ethical consideration important and encouraging for it increased justice and empathy in the teachers´ work.
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I have more often thought over what I am thinking and also I have often told it to others - professional development and collegial feedback on kindergarten teams. The need for professional feedback surfaces year after year in enquiries made among staff members in the field of early childhood education. Because the pressure to be effective adds to the workload of the heads of kindergartens, there are few opportunities to give staff concrete feedback on a daily basis. Because peers are able to observe each other close at hand, their reciprocal feedback can compensate for that of the kindergarten head. In this study the practical training process of collegial feedback is studied and also the opportunities for feedback as a means of supporting professional development in the context of kindergarten. The development project involving the entire kindergarten community (N=21) was implemented in 2003-2004 through three developing cycles. The Johar´s Window , produced by Luft and Jung with the Model of Situational Leadership by Hersey and Blanchard, acted as a theoretical frame of reference. It has been used in this study both for its qualitative and its quantitative methods. The data were carried out through questions, interviews, diaries, written descriptions and monthly evaluations. The qualitative and quantitative methods were also used in analysing the data. The results showed that during the training process, the staff as a giver of feedback moved from the professional basic level to the professional maturity level. Their awareness of both their own and their peers´ know-how expanded from the initial state to the final state. It became evident that team size is the essential key element in the practise of giving feedback to team members. The team atmosphere and the commitment of the team members are in significant factors in the training of giving and receiving feedback. As a result of analyses, delivering feedback was grouped into three categories: developmental feedback, descriptive feedback and either supportive or destructive feedback. Receiving feedback was likewise groupped into three categories: aspiring to develop, unaccommodating and accepting. The ability to control feelings improved along with the skills of giving feedback; it was possible to analyse development through the professional development model represented in the theory of the study. The results showed that professional know-how of other kinds also developed during the process. Giving feedback among fellow workers enables team members to receive feedback everyday. Training to give feedback means examining a field of professional know-how and also formulating shared rules. The results of this study give support to previous studies that have emphasised practical training in natural circumstances. Keywords: feedback, professional development, learning at work
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The aim of this study is to survey the meaning of craftmanship in goldsmith occupation. The image of craftmanship is built theoretically as well as researcher's own practical experience. The study describes a dialogue between self-employed goldsmith s everyday work and trade union's opinion. Suomen Kultaseppien Liitto (The Goldsmith Assosiation of Finland) was chosen forthe trade union, because it is the biggest, the oldest and the most influential on the occupational area. The research data are volumes 1995 - 1998 of occupational membership journal of Suomen Kultaseppien Liitto. The data analyzed with Adapted Content Analysis and Grounded Theory. The professional occupation of goldsmiths, the role of craftmanship and the future of the occupation are discussed. Additionally, the relationship between the Suomen Kultaseppien Liitto and occupational culture and profession of goldsmiths was studied. Craft and craftmanship is most often discussed in articles related to tradition and education.Craftmanship is understood very idealistically, with little meaning in practical life. St. Eligius and the skill and art of goldsmiths in St Petersburg are raised to symbols of craftmanship. The occupational image is broken and a clear conflict between education and occupation is visible. Education produces artist-craftsmen, while handicraft workers are required in industry, and retailers or specially trained store assistant in business. Computer-aided design and manufacture render handicraft workmanship unnecessary. In a pessimistic view, the future possibilities of the goldsmith occupational profession are dim, because the artist-craftsmen are bound to lose to fast-paced machines. On the other hand, people involved in goldsmith education see the future light, designer-goldsmiths developing the occupational to new dimensions. Suomen Kultaseppien Liitto represents goldsmiths in public. The union, however is governed by non-artisan goldsmiths. The union stresses business attitudes and enterpreneurship, and has succeeded in protecting the privileges of retailers and industry. Goldsmiths profession is seen in the research data as a combination of precious-metal industry, jewellery and watch stores, anda goldsmith shop is considered a specialized giftstore. The goldsmiths occupation is not a profession, and the Suomen Kultaseppien Liitto is not a trade union for artist and craftmen. Accordingly, part of the representative authority of the union could be transferred from the Association to Taidekäsityöläiset Taiko ry, a member of organization of Ornamo. Results of this study show the importance of defining the images of the goldsmith occupational profession and the trade union. The results could be applied to goldsmith education to examine what would be the optimal education and training for present employment opportunities. The important background theories has been the theories of Habermas and Lévi-Strauss.
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Aims: The older the youngsters are, the more important role hobbies and leisure time activities have in their life. That is why various activities organized by the non-profit organizations have an important role concerning the development of food habits of youngsters. This study has three main themes. The themes and their respective study questions are: 1. The youngsters' conceptions on healthy eating and food choice: What kind of food do youngsters consider as healthy? How do they see their own eating habits from this point of view? 2. The youngsters and the significance of everyday food-related information: How do the youngsters perceive the role of different actors and these actors' role regarding their own food habits and food choice? 3. The possibilities of the organizations that work with youngsters to improve their food habits: What kind of role do the non-profit organizations have on the youngsters' food habits and healthy food choice? Methods: This study comprises of two types of data. First, a quantitative internet-based survey (N=582) was used to collect data on the 9th graders conceptions and understandings. The data was analyzed with the SPSS-program. Means, cross-tabulations, Pearson´s correlations and t-test were calculated from the data. The qualitative data was collected using interviews. The respondents were 12 experts from non-profit organizations. The interviews were analyzed with the qualitative content analysis. Results and conclusions: The non-profit organizations studied have good possibilities to communicate with youngsters through their hobbies. As part of their activities these organizations are able to influence on health-promoting lifestyle and food habits of youngsters. In order to reach more youngsters, these organizations should actively act e.g. in virtual societies of youngsters. Youngsters will participate when activities are voluntary and exhilarating. From the point of food habits doing, learning and identifying are the most important factors to engage the young. Also the models of peers and adults are important. Non-profit organizations should offer youngsters activities but these organizations should also influence on society.
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Tutkimuksen tavoitteena oli selvittää koulujen profiloitumisen ja opettajien vaihtuvuuden välistä yhteyttä. Nykyisen koulutuspolitiikan mukaisesti koulujärjestelmämme päätäntävalta on siirtynyt yhä enemmän koulujen tasolle ja mahdollistaa siten kouluille oikeuden päättää melko itsenäisesti tarjoamansa opetuksen sisällöistä, tavoitteista ja menettelytavoista. Kouluilla on myös oikeus laatia omat opetussuunnitelmansa ja näin profiloitua haluamalleen painotusalueelle. Työvoiman liikkuvuuden myötä myös opettajat vaihtavat työpaikkaansa. Käytännössä tämä tarkoittaa opettajien siirtymistä kouluista ja tehtävistä toisiin eripituisten työskentelyjaksojen jälkeen. Tällaisesta vaihtuvuudesta ja sen vaikutuksista koulun työskentelyilmapiiriin sekä kaikkiin koulumaailman osapuoliin voidaan kuitenkin olla montaa eri mieltä. Erityisesti vaikutukset johonkin pienempään opetusyksikköön voivat olla melkoiset. Tutkimus toteutettiin eräässä helsinkiläisen ala-asteen koulussa, keskittyen opettajien vaihtuvuuden tarkasteluun Montessori-pedagogiikalla opetettavassa yhdysluokassa. Tutkimukseen sisällytettiin Montessori-luokan oppilaat, heidän vanhempansa sekä koulun opettajat. Tutkimus suoritettiin kirjallisuuteen perehtyen, luokkaa observoiden, oppilaita ja opettajia haastatellen sekä vanhemmilla kirjoitelmia teettäen. Aineiston suppeuden ja tutkimuksen case study -luonteen vuoksi vaihtuvuuden moninaisia vaikutuksia ilmentäviä tutkimustuloksia ei kuitenkaan voida yleistää. Avainsanat: profiloituminen, vaihtuvuus, vaihtuvuuden vaikutukset, Montessori-pedagogiikka Keywords: profilation, changing, effects of changing, Montessori method
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In this thesis, taking place within the clothing industry of Finland, the impact of the globalisation of the economy on the pattern maker s job was studied and the present day fields of know-how of the job were found out. The thesis answers the questions, what are the characteristics of the patternmaker s job nowadays, and what areas of the know-how in the patternmaker s job form the core know-how, which is repeated in every organisation. Earlier studies of the subject do not exist in Finland. Similar studies have been made in USA (Staples 1993) and in Estonia (2002). Patternmakers who took part in this study were located in the Finnish clothing companies manufacturing or having clothes manufactured in series production, like clothing industry or chain of stores. A methodical triangulation was used in the thesis. In a phenomenological research of experience seven patternmakers were interviewed and in a quantitative research 26 patternmakers filled in a structured questionnaire. The phenomenological analysis has 2 parts. In the first phase using the professional background of the patternmakers, the historical development of the clothing industry for the last 40 years was described. In the second phase of the phenomenological analysis the description of the patternmaker s job was created based on the organisational strategy of the companies nowadays. The analysis of quantitative research material was performed by one-dimensional study of variables, where the variations in the amounts of variables lead to proportional conclusions. As a result of the structured questionnaire, the core know-how of the patternmaker was pointed out. In the thesis, the concept of situationality was used to describe the continuous change in the clothing industry. This explains the continuous requirement of patternmakers commitment to the time and location. The researcher has a background of a patternmaker and she works as a specialist instructor. With the thesis the researcher updates her professional competence. The analysis of the patternmaker s job can be used to update the content of patternmakers education in the vocational schools.
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The aim of the study was to find out what kind of view on product quality dressmaker and customer have, how the views differ from each other and how the difference affects dressmaker s work as an entrepreneur. The research data consists of eight thematic interviews: four dressmakers and four customers were interviewed for the study. In the core of customised dressmaking is arelationship between a maker and a client. The product of a dressmaker, a unique dress, is created in an immediate interaction between a dressmaker and a client. Also the quality of a unique dress derives from this interaction. In the results of this study, the views on quality are linked with six themes: dress, process, dressmaker, customer, interaction and enterprise. The dressmakers and the customers agree that the quality of a custom-made dress is based on unique fit. Describing the process the dressmakers insist on the quality of manufacturing. The clients' view on process insists on those phases where they themselves take part: designing and fitting. The personality of the dressmaker is part of quality in both the dressmakers' and the customers' points of view. The dressmakers and the customers are also aware of the customers impact on fulfilling the expectations. The immediate interaction between dressmaker and customer is a key to the unique dressmaking. At its best the interaction is followed by a trusting relationship. Entrustment derives also from a good reputation, which is essential in dressmaker-entrepreneurs marketing strategy. The dressmakers views on quality are product- and manufacturing-based. According to the results of the study there can be seen different types of dressmakers, that emphasise different aspects of quality. At the other end is a manufacturing-based, even transcendent view on quality, which rests on the values of the dressmaker. At the other end lies a customer- and value-based approach, which is founded on fulfilling the expectations and needs of the customer. In their views on quality the customers emphasise the immediate interaction between dressmaker and client. Keywords: quality, dressmaker, customer, entrepreneur
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The educational reform, launched in Finland in 2008, concerns the implementation of the Special Education Strategy (Opetusministeriö 2007) under an improvement initiative called Kelpo. One of the main proposed alterations of the Strategy relates to the support system of comprehensive school pupils. The existed two-level model (general and special support) is to be altered by the new three-level model (general, intensified and special support). There are 233 municipalities involved nationwide in the Kelpo initiative, each of which has a municipal coordinator as a national delegate. The Centre for Educational Assessment [the Centre] at the University of Helsinki, led by Professor Jarkko Hautamäki, carries out the developmental assessment of the initiative’s developmental process. As a part of that assessment the Centre interviewed 151 municipal coordinators in November 2008. This thesis considers the Kelpo initiative from Michael Fullan’s change theory’s aspect. The aim is to identify the change theoretical factors in the speech of the municipal coordinators interviewed by the Centre, and to constitute a view of what the crucial factors in the reform implementation process are. The appearance of the change theoretical factors, in the coordinators’ speech, and the meaning of these appearances are being considered from the change process point of view. The Centre collected the data by interviewing the municipal coordinators (n=151) in small groups of 4-11 people. The interview method was based on Vesala and Rantanen’s (2007) qualitative attitude survey method which was adapted and evolved for the Centre’s developmental assessment by Hilasvuori. The method of the analysis was a qualitative theory-based content analysis, processed using the Atlas.ti software. The theoretical frame of reference was grounded on Fullan’s change theory and the analysis was based on three change theoretical categories: implementation, cooperation and perspectives in the change process. The analysis of the interview data revealed spoken expressions in the coordinators’ speech which were either positively or negatively related to the theoretical categories. On the grounds of these change theoretical relations the existence of the change process was observed. The crucial factors of reform implementation were found, and the conclusion is that the encounter of the new reform-based and already existing strategies in school produces interface challenges. These challenges are particularly confronted in the context of the implementation of the new three-level support model. The interface challenges are classified as follows: conceptual, method-based, action-based and belief-based challenges. Keywords: reform, implementation, change process, Michael Fullan, Kelpo, intensified support, special support
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The aim of this work was to study what kind of working grips people use to knit in Finland and decide if one grip is superior to others. I investigated how knitters have adopted their grips and how they experience their knitting. I also explored whether it is possible to change one's grip. To provide a theoretical basis for the research I observed knitting in terms of culture, skill and ergonomics. The first part of the study material comprised video recordings of the grips of 95 knitters together with background information collected via a questionnaire during the education of craft teachers at the University of Helsinki in spring 2004, 2005 and 2006. Using the data obtained I focused on three knitters, whose grip of the knitting needles clearly differed from the ergonomically good grip. In addition to them I interviewed one student, who had changed over to more ergonomic way of knitting after participating in the first part of this study. In this respect my study is a several events' case study. In order to analyse my data I used both qualitative and quantitative content analysis methods to complement each other. Most of my research participants had learned to knit in first years of elementary school or comprehensive school. Almost everyone had adopted the basics of knitting by imitating, and many of them had corrected "incorrect" positions from verbal instructions. Through practice the imitated position had gradually become the style unique to each knitter. The findings showed that students' background in knitting is quite varied due to the diverse level of craft teaching. This is reflected in their knitting grips and their interest in knitting. Students do not think that there is one right working grip. The most important thing is that working seems as fluent and relaxed as possible, at which point knitting is easy and flows freely. They often consider their own style so pleasing and well-functioning that they do not think there could be any room for improvement. This study pointed out that, while it is possible to change a knitter's working grip, there is a bigger challenge in acknowledging weaknesses in one's know how. According to the results of my research, the most common working grip among Finnish knitters' corresponds with the grip that has been described as ergonomically good. Over one third of all participants knitted this way. Hands keep the knitting firmly but without tension. The forefinger that guides the yarn from the ball rests gently against the knitting needle, and the yarn goes in front of the first joint of the forefinger. The position of the hands and loops is the same as in the ergonomically good grip, i.e. the fingertips of both hands and the loops are near the tips of the knitting needles, so that the fingers only have to move small distances. When knitters purl and plain, they commonly pick up the yarn from the back of the knitting needle in the same way as when knitting. While researching the common features of working grips I have learned what abnormal grips are like. Although I recognized many different ways to knit, all the peculiar grips were modifications of the continental way of knitting. The results of this study give a clear picture of those points knitters should focus their attention on in order to gain a good hold of the needles.
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Sleep deprivation leads to increased subsequent sleep length and depth and to deficits in cognitive performance in humans. In animals extreme sleep deprivation is eventually fatal. The cellular and molecular mechanisms causing the symptoms of sleep deprivation are unclear. This thesis was inspired by the hypothesis that during wakefulness brain energy stores would be depleted, and they would be replenished during sleep. The aim of this thesis was to elucidate the energy metabolic processes taking place in the brain during sleep deprivation. Endogenous brain energy metabolite levels were assessed in vivo in rats and in humans in four separate studies (Studies I-IV). In the first part (Study I) the effects of local energy depletion on brain energy metabolism and sleep were studied in rats with the use of in vivo microdialysis combined with high performance liquid chromatography. Energy depletion induced by 2,4-dinitrophenol infusion into the basal forebrain was comparable to the effects of sleep deprivation: both increased extracellular concentrations of adenosine, lactate, and pyruvate, and elevated subsequent sleep. This result supports the hypothesis of a connection between brain energy metabolism and sleep. The second part involved healthy human subjects (Studies II-IV). Study II aimed to assess the feasibility of applying proton magnetic resonance spectroscopy (1H MRS) to study brain lactate levels during cognitive stimulation. Cognitive stimulation induced an increase in lactate levels in the left inferior frontal gyrus, showing that metabolic imaging of neuronal activity related to cognition is possible with 1H MRS. Study III examined the effects of sleep deprivation and aging on the brain lactate response to cognitive stimulation. No physiologic, cognitive stimulation-induced lactate response appeared in the sleep-deprived and in the aging subjects, which can be interpreted as a sign of malfunctioning of brain energy metabolism. This malfunctioning may contribute to the functional impairment of the frontal cortex both during aging and sleep deprivation. Finally (Study IV), 1H MRS major metabolite levels in the occipital cortex were assessed during sleep deprivation and during photic stimulation. N-acetyl-aspartate (NAA/H2O) decreased during sleep deprivation, supporting the hypothesis of sleep deprivation-induced disturbance in brain energy metabolism. Choline containing compounds (Cho/H2O) decreased during sleep deprivation and recovered to alert levels during photic stimulation, pointing towards changes in membrane metabolism, and giving support to earlier observations of altered brain response to stimulation during sleep deprivation. Based on these findings, it can be concluded that sleep deprivation alters brain energy metabolism. However, the effects of sleep deprivation on brain energy metabolism may vary from one brain area to another. Although an effect of sleep deprivation might not in all cases be detectable in the non-stimulated baseline state, a challenge imposed by cognitive or photic stimulation can reveal significant changes. It can be hypothesized that brain energy metabolism during sleep deprivation is more vulnerable than in the alert state. Changes in brain energy metabolism may participate in the homeostatic regulation of sleep and contribute to the deficits in cognitive performance during sleep deprivation.
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Distinct endogenous network events, generated independently of sensory input, are a general feature of various structures of the immature central nervous system. In the immature hippocampus, these type of events are seen as "giant depolarizing potentials" (GDPs) in intracellular recordings in vitro. GABA, the major inhibitory neurotransmitter of the adult brain, has a depolarizing action in immature neurons, and GDPs have been proposed to be driven by GABAergic transmission. Moreover, GDPs have been thought to reflect an early pattern that disappears during development in parallel with the maturation of hyperpolarizing GABAergic inhibition. However, the adult hippocampus in vivo also generates endogenous network events known as sharp (positive) waves (SPWs), which reflect synchronous discharges of CA3 pyramidal neurons and are thought to be involved in cognitive functions. In this thesis, mechanisms of GDP generation were studied with intra- and extracellular recordings in the neonatal rat hippocampus in vitro and in vivo. Immature CA3 pyramidal neurons were found to generate intrinsic bursts of spikes and to act as cellular pacemakers for GDP activity whereas depolarizing GABAergic signalling was found to have a temporally non-patterned facilitatory role in the generation of the network events. Furthermore, the data indicate that the intrinsic bursts of neonatal CA3 pyramidal neurons and, consequently, GDPs are driven by a persistent Na+ current and terminated by a slow Ca2+-dependent K+ current. Gramicidin-perforated patch recordings showed that the depolarizing driving force for GABAA receptor-mediated actions is provided by Cl- uptake via the Na-K-C1 cotransporter, NKCC1, in the immature CA3 pyramids. A specific blocker of NKCC1, bumetanide, inhibited SPWs and GDPs in the neonatal rat hippocampus in vivo and in vitro, respectively. Finally, pharmacological blockade of the GABA transporter-1 prolonged the decay of the large GDP-associated GABA transients but not of single postsynaptic GABAA receptor-mediated currents. As a whole the data in this thesis indicate that the mechanism of GDP generation, based on the interconnected network of bursting CA3 pyramidal neurons, is similar to that involved in adult SPW activity. Hence, GDPs do not reflect a network pattern that disappears during development but they are the in vitro counterpart of neonatal SPWs.
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Glaucoma is a multifactorial long-term ocular neuropathy associated with progressive loss of the visual field, retinal nerve fiber structural abnormalities and optic disc changes. Like arterial hypertension it is usually a symptomless disease, but if left untreated leads to visual disability and eventual blindness. All therapies currently used aim to lower intraocular pressure (IOP) in order to minimize cell death. Drugs with new mechanisms of action could protect glaucomatous eyes against blindness. Renin-angiotensin system (RAS) is known to regulate systemic blood pressure and compounds acting on it are in wide clinical use in the treatment of hypertension and heart failure but not yet in ophthalmological use. There are only few previous studies concerning intraocular RAS, though evidence is accumulating that drugs antagonizing RAS can also lower IOP, the only treatable risk factor in glaucoma. The main aim of this experimental study was to clarify the expression of the renin-angiotensin system in the eye tissues and to test its potential oculohypotensive effects and mechanisms. In addition, the possible relationship between the development of hypertension and IOP was evaluated in animal models. In conclusion, a novel angiotensin receptor type (Mas), as well as ACE2 enzyme- producing agonists for Mas, were described for the first time in the eye structures participating in the regulation of IOP. In addition, a Mas receptor agonist significantly reduced even normal IOP. The effect was abolished by a specific receptor antagonist. Intraocular, local RAS would thus to be involved in the regulation of IOP, probably even more in pathological conditions such as glaucoma though there was no unambiguous relationship between arterial and ocular hypertension. The findings suggest the potential as antiglaucomatous drugs of agents which increase ACE2 activity and the formation of angiotensin (1-7), or activate Mas receptors.
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Androgens control a variety of developmental processes that create the male phenotype and are important for maintaining male fertility and normal functions of tissues and organs that are not directly involved in procreation. Androgen receptor (AR) that mediates the biological actions of androgens is a member of the nuclear receptor superfamily of ligand-inducible transcription factors. Although AR was cloned over 15 years ago, the mechanisms by which it regulates gene expression are not well understood. A growing body of in vitro experimental evidence suggests that a complex network of proteins is involved in the androgen-dependent transcriptional regulation. However, the process of AR-dependent transcriptional regulation under physiological conditions is largely elusive. In the present study, a series of experiments were performed, including quantitative chromatin immunoprecipitation (ChIP) assays, to investigate AR-mediated transcription process using living prostate cancer cells. Our results show that the loading of AR and recruitment of coactivators and RNA polymerase II (Pol II) to both the promoter and enhancer of AR target genes are a transient and cyclic event that in addition to hyperacetylation, also involves dynamic changes in methylation, phosphorylation of core histone H3 in androgen-treated LNCaP cells. The dynamics of testosterone (T)-induced loading of AR onto the proximal promoters of the genes clearly differed from that loaded onto the distal enhancers. Significantly, more holo-AR was loaded onto the enhancers than the promoters, but the principal Pol II transcription complex was assembled on the promoters. By contrast, the pure antiandrogen bicalutamide (CDX) complexed to AR elicited occupancy of the PSA promoter, but was unable to load onto the PSA enhancer and was incapable of recruiting Pol II, coactivators and following changes of covalent histone modifications. The partial antagonist cyproterone acetate (CPA) and mifepristone (RU486) were capable of promoting AR loading onto both the PSA promoter and enhancer at a comparable efficiency with androgen in LNCaP cells expressing mutant AR. However, CPA- and RU486-bound AR not only recruited Pol II and coactivator p300 and GRIP1 onto the promoter and enhancer, but also recruited the corepressor NCoR onto the promoter as efficiently as CDX. In addition, we demonstrate that both proteasome and protein kinases are implicated in AR-mediated transcription. Even though proteasome inhibitor MG132 and protein kinase inhibitor DRB (5, 6-Dichlorobenzimidazole riboside) can block ligand-dependent accumulation of PSA mRNA with same efficiency, their use results in different molecular profiles in terms of the formation of AR-mediated transcriptional complex. Collectively, these results indicate that transcriptional activation by AR is a complicated process, which includes transient loading of holo-AR and recruitment of Pol II and coregulators accompanied by a cascade of distinct covalent histone modifications; This process involves both the promoter and enhancer elements, as well as other general components of the cell machineries e.g. proteasome and protein kinase; The pure antiandrogen CDX and the partial antagonist CPA and RU486 exhibit clearly different profiles in terms of their ability to induce the formation of AR-dependent transcriptional complexes and the histone modifications associated with the target genes in human prostate cancer cells. Finally, by using quantitative RT-PCR to compare the expression of sixteen AR co-regulators in prostate cancer cell lines, xenografts, and clinical prostate cancer specimens we suggest that AR co-regulators protein inhibitor of activated STAT1 (PIAS1) and steroid receptor coactivator 1(SRC1) could be involved in the progression of prostate cancer.
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Tissue destruction associated with the periodontal disease progression is caused by a cascade of host and microbial factors and proteolytic enzymes. Aberrant laminin-332 (Ln-332), human beta defensin (hBD), and matrix metalloproteinase (MMP) functions have been found in oral inflammatory diseases. The null-allele mouse model appears as the next step in oral disease research. The MMP-8 knock-out mouse model allowed us to clarify the involvement of MMP-8 in vivo in oral and related inflammatory diseases where MMP-8 is suggested to play a key role in tissue destruction. The cleaved Ln-332 γ2-chain species has been implicated in the apical migration of sulcular epithelial cells during the formation of periodontal pockets. We demonstrated that increased Ln-332 fragment levels in gingival crevicular fluid (GCF) are strongly associated with the severity of inflammation in periodontitis. Porphyromonas gingivalis trypsin-like proteinase can cleave an intact Ln-332 γ2-chain into smaller fragments and eventually promote the formation of periodontal pockets. hBDs are components of an innate mucosal defense against pathogenic microbes. Our results suggest that P. gingivalis trypsin-like proteinase can degrade hBD and thus reduce the innate immune response. Elevated levels and the increased activity of MMPs have been detected in several pathological tissue-destructive conditions where MMPs are shown to cleave extracellular matrix (ECM) and basement membrane (BM) molecules and to facilitate tissue destruction. Elevated levels of MMP-8 have been reported in many inflammatory diseases. In periodontitis, MMP-8 levels in gingival crevicular fluid (GCF) and in peri-implant sulcular fluid (PISF) are elevated at sites of active inflammation, and the increased levels of MMP-8 are mainly responsible for collagenase activity, which leads to tissue destruction. MMP-25, expressed by neutrophils, is involved in inflammatory diseases and in ECM turnover. MMP-26 can degrade ECM components and serve as an activator of other MMP enzymes. We further confirmed that increased levels and activation of MMP-8, -25, and -26 in GCF, PISF, and inflamed gingival tissue are associated with the severity of periodontal/peri-implant inflammation. We evaluated the role of MMP-8 in P. gingivalis-induced periodontitis by comparing MMP-8 knock-out (MMP8-/-) and wild-type mice. Surprisingly, MMP-8 significantly attenuated P. gingivalis-induced site-specific alveolar bone loss. We also evaluated systemic changes in serum immunoglobulin and lipoprotein profiles among these mouse groups. P. gingivalis infection increased HDL/VLDL particle size in the MMP-8-/- mice, which is an indicator of lipoprotein responses during systemic inflammation. Serum total LPS and IgG antibody levels were enhanced in both mice groups. P. gingivalis-induced periodontitis, especially in MMP-8-/- mice, is associated with severe alveolar bone loss and with systemic inflammatory and lipoprotein changes that are likely to be involved in early atherosclerosis.