9 resultados para 6-47

em Helda - Digital Repository of University of Helsinki


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The purpose of this follow-up study is to analyse stages of learning and teaching of children with special needs in pre-school and the first two grades of elementary school. The target group included 270 children with special needs. The three year follow-up period for each child began during the pre-school year, and continued until the spring of the second grade in elementary school. Various diagnoses were detected among children in the study group. The disorders were categorised in six classes: the developmentally delayed, children with language development disorder, children with emotional and behavioural disorders, children with attention deficit, children with other non-cognitive disorders and children with extensive developmental disorders. The study's starting point was the situation in pre-school: how the children were placed in pre-school, and what kinds of support they were offered? The purpose of the study was to describe how children with special needs move from different types of groups in pre-school to the different types of classes in the first two grades of elementary school. I also examined how well the children with special needs succeeded in the first two grades of elementary school. An additional purpose was to find out what connections there may be between the paths taken by children with special needs when they move from pre-school to elementary school, the types of support they get, and how they succeed academically in elementary school. The data were gathered mainly by means of questionnaires. In addition the children were studied by means of tests designed to estimate their academic skills at the end of the second grade. In analysing the data I used both quantitative and qualitative methods. Six paths were identified among the children in the study group, based on whether a child was in a group or a class given special teaching or in an ordinary group or class during pre-school and the first two grades of elementary school. In this study, about 53% of the children with special needs moved from pre-school to a regular class in elementary school, and about 47% of the children received special education in elementary school. Among the ordinary groups (n = 69) in pre-school the majority of children (73 %) moved to a regular class in elementary school. Among the children receiving special education (n = 201) in pre-school, 46% moved to a regular class in elementary school. That path turned out to be the one followed by the greatest number of children. Only rarely did children move from an ordinary group in pre-school to a special education class in elementary school. Examination of the results according to the children's transition paths also links together with the viewpoint of integration and segregation. This study indicates that in pre-school special education groups, a significantly greater number of methods supporting children's development were used than in the conventional education groups. The difference was at its greatest inconnection with the use of so-called special rehabilitation methods. A quite wide range of variation was observed in how the children succeeded in elementary school. Success in the tests designed to estimate the children's academic skills was poor for 31% of the children (n = 230) in the first grade study group. For 69 % of the children, however, success in the tests was at least satisfactory. In the second grade study group 34 % of the children (N = 216) got through all the three tests estimating academic skills acceptably. According to this study, a number of children with special needs require special support throughout pre-school and the first two grades of elementary school. The results show that if the children received special support during the pre-school year, a number were able to participate in regular education in elementary school. Keywords: a child with special needs, measures of support, transitions, achievements in school

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The aim of the thesis was to compare the correspondence of the outcome a computer assisted program appearance compared to the original image. The aspect of the study was directed to embroidery with household machines. The study was made from the usability point of view with Brother's PE-design 6.0 embroidery design programs two automatic techniques; multicoloured fragment design and multicoloured stitch surface design. The study's subject is very current because of the fast development of machine embroidery. The theory is based on history of household sewing machines, embroidery sewing machines, stitch types in household sewing machines, embroidery design programs as well as PE-design 6.0 embroidery design program's six automatic techniques. Additionally designing of embroidery designs were included: original image, digitizing, punching, applicable sewing threads as well as the connection between embroidery designs and materials used on embroidery. Correspondences of sewn appearances were examined with sewing experimental methods. 18 research samples of five original image were sewn with both techniques. Experiments were divided into four testing stages in design program. Every testing stage was followed by experimental sewing with Brother Super Galaxie 3100D embroidery machine. Experiments were reported into process files and forms made for the techniques. Research samples were analysed on images syntactic bases with sensory perception assessment. Original images and correspondence of the embroidery appearances were analysed with a form made of it. The form was divided into colour and shape assessment in five stage-similarity-scale. Based on this correspondence analysis it can be said that with both automatic techniques the best correspondence of colour and shape was achieved by changing the standard settings and using the makers own thread chart and edited original image. According to the testing made it is impossible to inform where the image editing possibilities of the images are sufficient or does the optimum correspondence need a separate program. When aiming at correspondence between appearances of two images the computer is unable to trace by itself the appearance of the original image. Processing a computer program assisted embroidery image human perception and personal decision making are unavoidable.

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Tutkimuksen tavoitteena oli kartoittaa ja kehittää modernia opiskeluympäristöä hyödyntävää kirjallisuuspiiritoimintaa ja sitä kautta edistää oppilaiden mahdollisuuksia osallistua elämyksellistä lukemista painottavaan kirjallisuuspiiriin sekä vahvistaa heidän kiinnostustaan tieto- ja viestintätekniikan käyttöön. Tutkimusaineisto kerättiin lukuvuonna 1997 1998 kyselyin ja haastatteluin sekä observoimalla lähiopetustilanteita ja virtuaaliryhmien sähköpostiviestintää. Lisäksi käytettiin valmiita dokumentteja ja asiakirjoja. Tutkimusjoukkona oli Matildaan osallistuneet 4.-6. luokan oppilaat kuudelta Espoon ala-asteelta sekä neljä tutoria, koordinaattori ja joitakin luokanopettajia Matilda-kouluista. Tutkimusongelmat suuntautuivat pääasiassa matildalaisten kokemuksiin opiskelusta modernissa opiskeluympäristössä, suhteesta tieto- ja viestintätekniikkaan sekä siihen, mitä uutta lukemiseen ja kirjallisuuteen liittyvää he kertoivat oppineensa ja kokeneensa. Koska tutkimuskohteen kaltaisia kokeiluita, joissa yhdistyy kirjallisuuspiiritoiminta ja moderni tieto- ja viestintätekniikka, ei ainakaan Suomessa ole aikaisemmin ollut, päädyttiin tutkimusmetodologian valinnassa kvalitatiiviseen otteeseen. Tutkimusote noudatti tapaustutkimuksen ja kehittämistutkimuksen periaatteita. Vaikka tutkimus oli menetelmältään kvalitatiivinen, aineistoa käsiteltiin myös kvantifioiden, mutta yleistyksiä tehtiin ainoastaan tapauksen suuntaan. Tutkimustulokset osoittivat, että opiskelu oli oppilaille positiivinen kokemus. He pitivät erityisesti etäopiskelun itsenäisestä työskentelystä ja lähiopetuspäivistä. Heidän suhtautumisensa tieto- ja viestintätekniikkaan muuttui positiivisemmaksi ja heidän taitonsa tieto- ja viestintätekniikan käyttäjinä kehittyivät. Oppilaat saivat positiivisia lukukokemuksia, heidän lukualueensa laajeni ja osa heistä kertoi lukutyylinsä muutoksista ja syvenemisestä. Oppilaat kokivat ongelmallisimmaksi hankkeen sekavan tutorointi-systeemin, kiireisen aikataulun sekä tietokoneisiin ja -verkkoon liittyvät ongelmat. kirjallisuuspiiri, kolmilukutaito, lukutaito, kirjallisuus, lukeminen, elämyksellinenlukeminen, kirjallisuudenopetus, moderni opiskeluympäristö, avoin ja joustava opiskeluympäristö, telematiikka, tieto- ja viestintätekniikka reading circle, teaching of literature, tri-literacy, literacy, reading, literature, aestheticreading, modern learning enviroment, open anf flexible learning enviroment, telematics, modern information technology

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Total hip replacement is the golden standard treatment for severe osteoarthritis refractory for conservative treatment. Aseptic loosening and osteolysis are the major long-term complications after total hip replacement. Foreign body giant cells and osteoclasts are locally formed around aseptically loosening implants from precursor cells by cell fusion. When the foreign body response is fully developed, it mediates inflammatory and destructive host responses, such as collagen degradation. In the present study, it was hypothesized that the wear debris and foreign body inflammation are the forces driving local osteoclast formation, peri-implant bone resorption and enhanced tissue remodeling. Therefore the object was to characterize the eventual expression and the role of fusion molecules, ADAMs (an abbreviation for A Disintegrin And Metalloproteinase, ADAM9 and ADAM12) in the fusion of progenitor cells into multinuclear giant cells. For generation of such cells, activated macrophages trying to respond to foreign debris play an important role. Matured osteoclasts together with activated macrophages mediate bone destruction by secreting protons and proteinases, including matrix metalloproteinases (MMPs) and cathepsin K. Thus this study also assessed collagen degradation and its relationship to some of the key collagenolytic proteinases in the aggressive synovial membrane-like interface tissue around aseptically loosened hip replacement implants. ADAMs were found in the interface tissues of revision total hip replacement patients. Increased expression of ADAMs at both transcriptional and translational levels was found in synovial membrane-like interface tissue of revision total hip replacement (THR) samples compared with that in primary THR samples. These studies also demonstrate that multinucleate cell formation from monocytes by stimulation with macrophage-colony stimiulating factor (M-CSF) and receptor activator of nuclear factor kappa B ligand (RANKL) is characterized by time dependent changes of the proportion of ADAMs positive cells. This was observed both in the interface membrane in patients and in two different in vitro models. In addition to an already established MCS-F and RANKL driven model, a new virally (parainfluenza 2) driven model (of human salivary adenocarcinoma (HSY) cells or green monkey kidney (GMK) cells) was developed to study various fusion molecules and their role in cell fusion in general. In interface membranes, collagen was highly degraded and collagen degradation significantly correlated with the number of local cells containing collagenolytic enzymes, particularly cathepsin K. As a conclusion, fusion molecules ADAM9 and ADAM12 seem to be dynamically involved in cell-cell fusion processes and multinucleate cell formation. The highly significant correlation between collagen degradation and collagenolytic enzymes, particularly cathepsin K, indicates that the local acidity of the interface membrane in the pathologic bone and soft tissue destruction. This study provides profound knowledge about cell fusion and mechanism responsible for aseptic loosening as well as increases knowledge helpful for prevention and treatment.

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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.

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Various reasons, such as ethical issues in maintaining blood resources, growing costs, and strict requirements for safe blood, have increased the pressure for efficient use of resources in blood banking. The competence of blood establishments can be characterized by their ability to predict the volume of blood collection to be able to provide cellular blood components in a timely manner as dictated by hospital demand. The stochastically varying clinical need for platelets (PLTs) sets a specific challenge for balancing supply with requests. Labour has been proven a primary cost-driver and should be managed efficiently. International comparisons of blood banking could recognize inefficiencies and allow reallocation of resources. Seventeen blood centres from 10 countries in continental Europe, Great Britain, and Scandinavia participated in this study. The centres were national institutes (5), parts of the local Red Cross organisation (5), or integrated into university hospitals (7). This study focused on the departments of blood component preparation of the centres. The data were obtained retrospectively by computerized questionnaires completed via Internet for the years 2000-2002. The data were used in four original articles (numbered I through IV) that form the basis of this thesis. Non-parametric data envelopment analysis (DEA, II-IV) was applied to evaluate and compare the relative efficiency of blood component preparation. Several models were created using different input and output combinations. The focus of comparisons was on the technical efficiency (II-III) and the labour efficiency (I, IV). An empirical cost model was tested to evaluate the cost efficiency (IV). Purchasing power parities (PPP, IV) were used to adjust the costs of the working hours and to make the costs comparable among countries. The total annual number of whole blood (WB) collections varied from 8,880 to 290,352 in the centres (I). Significant variation was also observed in the annual volume of produced red blood cells (RBCs) and PLTs. The annual number of PLTs produced by any method varied from 2,788 to 104,622 units. In 2002, 73% of all PLTs were produced by the buffy coat (BC) method, 23% by aphaeresis and 4% by the platelet-rich plasma (PRP) method. The annual discard rate of PLTs varied from 3.9% to 31%. The mean discard rate (13%) remained in the same range throughout the study period and demonstrated similar levels and variation in 2003-2004 according to a specific follow-up question (14%, range 3.8%-24%). The annual PLT discard rates were, to some extent, associated with production volumes. The mean RBC discard rate was 4.5% (range 0.2%-7.7%). Technical efficiency showed marked variation (median 60%, range 41%-100%) among the centres (II). Compared to the efficient departments, the inefficient departments used excess labour resources (and probably) production equipment to produce RBCs and PLTs. Technical efficiency tended to be higher when the (theoretical) proportion of lost WB collections (total RBC+PLT loss) from all collections was low (III). The labour efficiency varied remarkably, from 25% to 100% (median 47%) when working hours were the only input (IV). Using the estimated total costs as the input (cost efficiency) revealed an even greater variation (13%-100%) and overall lower efficiency level compared to labour only as the input. In cost efficiency only, the savings potential (observed inefficiency) was more than 50% in 10 departments, whereas labour and cost savings potentials were both more than 50% in six departments. The association between department size and efficiency (scale efficiency) could not be verified statistically in the small sample. In conclusion, international evaluation of the technical efficiency in component preparation departments revealed remarkable variation. A suboptimal combination of manpower and production output levels was the major cause of inefficiency, and the efficiency did not directly relate to production volume. Evaluation of the reasons for discarding components may offer a novel approach to study efficiency. DEA was proven applicable in analyses including various factors as inputs and outputs. This study suggests that analytical models can be developed to serve as indicators of technical efficiency and promote improvements in the management of limited resources. The work also demonstrates the importance of integrating efficiency analysis into international comparisons of blood banking.

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The leading cause of death in the Western world continues to be coronary heart disease (CHD). At the root of the disease process is dyslipidemia an aberration in the relevant amounts of circulating blood lipids. Cholesterol builds up in the arterial wall and following rupture of these plaques, myocardial infarction or stroke can occur. Heart disease runs in families and a number of hereditary forms are known. The leading cause of adult dyslipidemia presently however is overweight and obesity. This thesis work presents an investigation of the molecular genetics of common, hereditary dyslipidemia and the tightly related condition of obesity. Familial combined hyperlipidemia (FCHL) is the most common hereditary dyslipidemia in man with an estimated population prevalence of 1-6%. This complex disease is characterized by elevated levels of serum total cholesterol, triglycerides or both and is observed in about 20% of individuals with premature CHD. Our group identified the disease to be associated with genetic variation in the USF1 transcription factor gene. USF1 has a key role in regulating other genes that control lipid and glucose metabolism as well as the inflammatory response all central processes in the progression of atherosclerosis and CHD. The first two works of this thesis aimed at understanding how these USF1 variants result in increased disease risk. Among the many, non-coding single-nucleotide polymorphisms (SNPs) that associated with the disease, one was found to have a functional effect. The risk-enhancing allele of this SNP seems to eradicate the ability of the important hormone insulin to induce the expression of USF1 in peripheral tissues. The resultant changes in the expression of numerous USF1 target genes over time probably enhance and accelerate the atherogenic processes. Dyslipidemias often represent an outcome of obesity and in the final work of this thesis we wanted to address the metabolic pathways related to acquired obesity. It is recognized that active processes in adipose tissue play an important role in the development of dyslipidemia, insulin resistance and other pathological conditions associated with obesity. To minimize the confounding effects of genetic differences present in most human studies, we investigated a rare collection of identical twins that differed significantly in the amount of body fat. In the obese, but otherwise healthy young adults, several notable changes were observed. In addition to chronic inflammation, the adipose tissue of the obese co-twins was characterized by a marked (47%) decrease in amount of mitochondrial DNA (mtDNA) a change associated with mitochondrial dysfunction. The catabolism of branched chain amino acids (BCAAs) was identified as the most down-regulated process in the obese co-twins. A concordant increase in the serum level of these insulin secretagogues was identified. This hyperaminoacidemia may provide the feed-back signal from insulin resistant adipose tissue to the pancreas to ensure an appropriately augmented secretory response. The down regulation of BCAA catabolism correlated closely with liver fat accumulation and insulin. The single most up-regulated gene (5.9 fold) in the obese co-twins was osteopontin (SPP1) a cytokine involved in macrophage recruitment to adipose tissue. SPP1 is here implicated as an important player in the development of insulin resistance. These studies of exceptional study samples provide better understanding of the underlying pathology in common dyslipidemias and other obesity associated diseases important for future improvement of intervention strategies and treatments to combat atherosclerosis and coronary heart disease.

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In this study, a predisposing gene for a recently characterized cancer syndrome, hereditary leiomyomatosis and renal cell cancer (HLRCC), was identified and the role of the gene was investigated in other familial cancers and in nonsyndromic tumorigenesis. HLRCC is a dominantly inherited disorder predisposing predominantly to uterine and skin leiomyomas, and also to renal cell cancer and uterine leiomyosarcoma. The disease gene was recently localized in Finnish families to 1q42-q43 by a genome-wide linkage search. Independently in the UK, a clinically similar condition, multiple cutaneous and uterine leiomyomata (MCUL), was linked to the same chromosomal region, strongly suggesting that HLRCC and MCUL are actually a single syndrome. Linkage results were confirmed by detecting loss of heterozygosity (LOH) at the disease locus in most of the patients' tumors, suggesting that this predisposing gene acts as a tumor suppressor. Through detailed investigation by genotyping of microsatellite markers and haplotype construction in Finnish and UK HLRCC/MCUL families we were able to narrow the disease locus down to 1.6 Mb. Extensive mutation screening of known and predicted transcripts in the target region resulted in identification of the HLRCC predisposing gene, fumarase (fumarate hydratase, FH). FH is a key enzyme in energy metabolism, catalyzing fumarate to malate in the tricarboxylic acid cycle (TCAC) in mitochondria. Germline alterations in FH segregating with the disease were detected in 25 of 42 HLRCC/MCUL families including whole-gene deletions, truncating small deletions/insertions and nonsense mutations, as well as substitutions or deletions of highly conserved amino acids. Biallelic inactivation was detected in almost all studied tumors of HLRCC patients. Furthermore, FH enzyme activity was reduced in the patients' normal tissues and was completely or virtually absent from tumors. Based on these findings, we extensively demonstrated that mutations in FH underlie the HLRCC/MCUL syndrome. In our studies of other familial cancers, evidence for involvement of FH defects was not found in familial prostate and breast cancers. To investigate the role of FH in sporadic tumorigenesis, we analyzed 652 lesions, including a series of 353 nonsyndromic counterparts of tumor types associated with HLRCC. Mutations in nonsyndromic tumors were rare and appeared to be limited to tumor types observed in the hereditary form of the disease. Biallelic inactivation of FH was detected in a uterine leiomyosarcoma, a cutaneous leiomyoma, a soft-tissue sarcoma, and in two uterine leiomyomas. In the uterine leiomyosarcoma and the cutaneous lesion FH mutations originated from the germline whereas the soft-tissue sarcoma harbored purely somatic changes. In uterine leiomyomas somatic mutations were detected in the two out of five tumors with LOH at the FH locus. Our findings demonstrate that FH inactivation is also involved in nonhereditary tumor development, and further support the hypothesis that FH acts as a tumor suppressor. The role of FH in predisposition to malignancies, renal cell carcinoma and leiomyosarcoma is important in the diagnosis and prevention of cancer among HLRCC patients. This study is of general clinical interest, because prior to our findings, little was known about the molecular genetics of uterine leiomyomas, the most common tumors of women.

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Human herpesvirus 6 (HHV-6) was identified from patients with HIV and lymphoproliferative diseases in 1986. It is a β-herpesvirus and is divided into two subgroups, variants A and B. HHV-6 variant B is the cause of exanthema subitum, while variant A has not yet definitely proven to cause any disease. HHV-6, especially variant A, is a highly neurotropic virus and has been associated with many diseases of the central nervous system (CNS) such as encephalitis and multiple sclerosis (MS). The present studies were aimed to elucidate the role of HHV-6 and its two variants in neurological infections. Special attention was given to study the possible role of HHV-6 in the pathogenesis of MS. We studied the expression of HHV-6 antigens using immunohistochemistry in brain autopsy samples from patients with MS and controls. HHV-6 antigen was identified in 70% of MS specimens whereas 30% of control specimens expressed HHV-6 antigen. Serum and cerebrospinal fluid (CSF) samples were collected from patients with MS and patients with other neurological diseases (OND) from patients visiting Helsinki University Central Hospital Neurological Outpatient Clinic during the years 2003 and 2004. In addition, we studied 53 children with suspected encephalitis. We developed an immunofluorescence IgG-avidity assay for the detection of primary HHV-6A and HHV-6B infection. For HHV-6B antibodies, no differences were observed between patients with MS and OND. For HHV-6A both seroprevalence and mean titers were significantly higher in MS compared to OND. HHV-6A low-avidity IgG antibodies, suggestive of primary infection, were found in serum of two, three and one patient with definite MS, possible MS and OND, respectively. From pediatric patients with suspected encephalitis, six serum samples (11.3%) contained low-avidity antibodies, indicating a temporal association between HHV-6A infection and onset of encephalitis. Three out of 26 patients with CDMS and four out of 19 patients with CPMS had HHV-6 antibodies in their CSF compared to none of the patients with OND (p=0.06 and p=0.01, respectively). Two patients with CDMS and three patients with CPMS appeared to have specific intrathecal synthesis of HHV-6A antibodies. In addition, oligoclonal bands (OCB) were observed in the CSF of five out of nine MS patients tested, and in two the OCBs reacted specifically with HHV-6 antigen, which is a novel finding. These results indicate HHV-6 specific antibody production in the CNS and suggest that there is a subset of MS patients with an active or chronic HHV-6A infection in the CNS that might be involved in the pathogenesis of MS. Our studies suggest that HHV-6 is an important causative or associated virus in some neurological infections, such as encephalitis and it might contribute to the development of MS, at least in some cases. In conclusion, HHV-6 is a neurotropic virus that should be taken into consideration when studying acute and chronic CNS diseases of unknown origin.