Mitochondrial disease in Southwestern Finland. Population-based molecular genetic and clinical studies

Mitochondria are present in all eukaryotic cells. They enable these cells utilize oxygen in the production of adenosine triphosphate in the oxidative phosphorylation system, the mitochondrial respiratory chain. The concept ‘mitochondrial disease’ conventionally refers to disorders of the respiratory chain that lead to oxidative phosphorylation defect. Mitochondrial disease in humans can present at any age, and practically in any organ system. Mitochondrial disease can be inherited in maternal, autosomal dominant, autosomal recessive, or X-chromosomal fashion. One of the most common molecular etiologies of mitochondrial disease in population is the m.3243A>G mutation in the MT-TL1 gene, encoding mitochondrial tRNALeu(UUR). Clinical evaluation of patients with m.3243A>G has revealed various typical clinical features, such as stroke-like episodes, diabetes mellitus and sensorineural hearing loss. The prevalence and clinical characteristics of mitochondrial disease in population are not well known. This thesis consists of a series of studies, in which the prevalence and characteristics of mitochondrial disease in the adult population of Southwestern Finland were assessed. Mitochondrial haplogroup Uk was associated with increased risk of occipital ischemic stroke among young women. Large-scale mitochondrial DNA deletions and mutations of the POLG1 gene were the most common molecular etiologies of progressive external ophthalmoplegia. Around 1% of diabetes mellitus emerging between the ages 18 – 45 years was associated with the m.3243A>G mutation. Moreover, among these young diabetic patients, mitochondrial haplogroup U was associated with maternal family history of diabetes. These studies demonstrate the usefulness of carefully planned molecular epidemiological investigations in the study of mitochondrial disorders.

Infective Endocarditis in a Finnish Teaching Hospital. 25 Years of Experience of Adult Patients

Infektiivinen endokardiitti yliopistollisessa keskussairaalassa vuosina 1980-2004 hoidetuilla aikuispotilailla Tausta: Infektiivinen endokardiitti on edelleen vakava sairaus. Huolimatta siitä, että taudin diagnostiikka ja hoito ovat kehittyneet, siihen liittyy edelleen merkittävää sairastuvuutta ja kuolleisuutta. Endokardiitin taudinkuvassa on viime vuosina tapahtunut muutoksia monissa maissa. Tavoitteet: Tutkia endokardiitin kliinista kuvaa ja ennustetta suomalaisessa yliopistosairaalassa vuosina 1980-2004 endokardiitin vuoksi hoidetuilla aikuispotilailla. Aineisto: Osatyössä I endokardiitin todennäköisyyttä analysoitiin 222:lla vuosina 1980-1995 endokardiittiepäilyn vuoksi hoidetulla potilaalla käyttäen apuna sekä Duken että von Reyn diagnostisia kriteereitä. Osatyössä II tutkittiin endokardiittiin liittyviä neurologisia komplikaatioita 218 varmassa tai mahdollisessa endokardiittiepisodissa. Osatyössä III tutkittiin seerumin C-reaktiivisen proteiinin (CRP) käyttökelpoisuutta hoitovasteen arvioinnissa 134:ssä varmaksi luokitellussa endokardiittiepisodissa. Osatyössä IV tutkittiin yleisbakteeri-PCRmenetelmän käyttökelpoisuutta etiologisessa diagnostiikassa 56:lla endokardiittiepäilyn vuoksi leikatulla potilaalla. Osatöissä V ja VI analysoitiin kaikki vuosina 1980-2004 hoidetut 303 endokardiittipotilasta lyhytaikais- ja 1-vuotisennusteen suhteen sekä tutkittiin endokardiitin taudinkuvassa tapahtuneita muutoksia sairaalassamme. Tulokset: Duken kriteerit osoittautuivat von Reyn kriteereitä herkemmiksi endokardiitin diagnostiikassa: 243 tutkitusta episodista 114 luokiteltiin varmoiksi endokardiiteiksi Duken kriteereillä, kun vastaavasti ainoastaan 64 luoteltiin varmoiksi von Reyn kriteereillä (p<0.001). Lisäksi peräti 115 episodissa endokardiitin diagnoosi hylättiin von Reyn kriteereillä, kun diagnoosi hylättiin Duken kriteereillä ainoastaan 37 episodissa (p<0.001). Neurologinen komplikaatio ilmeni ennen mikrobilääkehoidon aloittamista 76 %:ssa episodeja ollen ensimmäinen oire 47 %:ssa. Kuolema oli merkitsevästi yhteydessä neurologisiin komplikaatioihin. Hoitovastetta seurattaessa seerumin CRP:n lasku oli merkitsevästi nopeampaa komplikaatioitta toipuvilla potilailla kuin niillä, joille kehittyi komplikaatioita tai jotka menehtyivät tautiinsa. PCR-tutkimus poistetusta läpästä antoi ainoana menetelmänä etiologisen diagnoosin neljässä tapauksessa (2 stafylokokkilajia, 1 Streptococcus bovis,1 Bartonella quintana), joissa kaikissa mikrobilääkehoito oli ollut käytössä ennen näytteiden ottamista. Koko aineistossa kahden läpän infektio tai neurologisten komplikaatioiden, perifeeristen embolioiden tai sydämen vajaatoiminnan kehittyminen ennustivat sekä sairaalakuolleisuutta että 1-vuotiskuolleisuutta, kun taas ≥65 vuoden ikä ja sydämen ultraäänitutkimuksessa todettu vegetaatio tai Duken luokittelun mukainen pääkriteeri ennustivat kuolemaa vuoden sisällä. Korkea CRP-taso sairaalaan tullessa ennusti sekä sairaalakuolleisuutta että 1-vuotiskuolleisuutta. Huumeiden käyttäjien endokardiitit lisääntyivät tutkimusaikana merkitsevästi (p<0.001). Päätelmät: Tässä työssä vahvistetaan Duken kriteerien käyttökelpoisuus endokardiitin diagnostiikassa. Lisäksi vahvistui käsitys, että nopea diagnoosi ja mikrobilääkehoidon aloittaminen ovat parhaat keinot ehkäistä neurologisia komplikaatioita ja parantaa endokardiittipotilaiden ennustetta. CRP:n normalisoituminen on endokardiittipotilailla hyvän ennusteen merkki. Suoraan läppäkudoksesta tehty PCR-tutkimus on hyödyllinen, kun taudin aiheuttaja on kasvuominaisuuksiltaan vaativa tai potilas on saanut mikrobilääkehoitoa ennen viljelynäytteiden ottamista. Muutamat aiemmissa tutkimuksissa todetut huonon ennusteen merkit ennustavat huonoa ennustetta myös tämän tutkimuksen potilailla. Uutena löydöksenä ilmeni, että korkea CRP-arvo sairaalaan tullessa merkitsee sekä huonoa lyhyt- että pitkäaikaisennustetta. Huumeiden käyttäjien endokardiittien ilmaantuminen on tärkein epidemiologinen muutos 25 vuoden tutkimusaikana.

Kognitiiviset häiriöt skitsofreniassa : yhteys sairauden riskitekijöihin ja kliinisiin piirteisiin

Minna Torniaisen väitöskirja Cognitive impairment in schizophrenia : related risk factors and clinical characteristics (Helsingin yliopisto 2013).

Clinical Learning Environment and Supervision. Development and Validation of the CLES Evaluation Scale

The purpose of the study is: (1) to describe how nursing students' experienced their clinical learning environment and the supervision given by staff nurses working in hospital settings; and (2) to develop and test an evaluation scale of Clinical Learning Environment and Supervision (CLES). The study has been carried out in different phases. The pilot study (n=163) explored the association between the characteristics of a ward and its evaluation as a learning environment by students. The second version of research instrument (which was developed by the results of this pilot study) were tested by an expert panel (n=9 nurse teachers) and test-retest group formed by student nurses (n=38). After this evaluative phase, the CLES was formed as the basic research instrument for this study and it was tested with the Finnish main sample (n=416). In this phase, a concurrent validity instrument (Dunn & Burnett 1995) was used to confirm the validation process of CLES. The international comparative study was made by comparing the Finnish main sample with a British sample (n=142). The international comparative study was necessary for two reasons. In the instrument developing process, there is a need to test the new instrument in some other nursing culture. Other reason for comparative international study is the reflecting the impact of open employment markets in the European Union (EU) on the need to evaluate and to integrate EU health care educational systems. The results showed that the individualised supervision system is the most used supervision model and the supervisory relationship with personal mentor is the most meaningful single element of supervision evaluated by nursing students. The ward atmosphere and the management style of ward manager are the most important environmental factors of the clinical ward. The study integrates two theoretical elements - learning environment and supervision - in developing a preliminary theoretical model. The comparative international study showed that, Finnish students were more satisfied and evaluated their clinical placements and supervision with higher scores than students in the United Kingdom (UK). The difference between groups was statistical highly significant (p= 0.000). In the UK, clinical placements were longer but students met their nurse teachers less frequently than students in Finland. Arrangements for supervision were similar. This research process has produced the evaluation scale (CLES), which can be used in research and quality assessments of clinical learning environment and supervision in Finland and in the UK. CLES consists of 27 items and it is sub-divided into five sub-dimensions. Cronbach's alpha coefficient varied from high 0.94 to marginal 0.73. CLES is a compact evaluation scale and user-friendliness makes it suitable for continuing evaluation.

Molecular Characteristics of Neuroblastoma with Special Reference to Novel Prognostic Factors and Diagnostic Applications

Molecular Characteristics of Neuroblastoma with Special Reference to Novel Prognostic Factors and Diagnostic Applications Department of Medical Biochemistry and Genetics Annales Universitatis Turkuensis, Medica-Odontologica, 2009, Turku, Finland Painosalama Oy, Turku, Finland 2009 Background: Neuroblastoma, which is the most common and extensively studied childhood solid cancer, shows a great clinical and biological heterogeneity. Most of the neuroblastoma patients older than one year have poor prognosis despite intensive therapies. The hallmark of neuroblastoma, biological heterogeneity, has hindered the discovery of prognostic tumour markers. At present, few molecular markers, such as MYCN oncogene status, have been adopted into clinical practice. Aims: The aim of the study was to improve the current prognostic methodology of neuroblastoma, especially by taking cognizance of the biological heterogeneity of neuroblastoma. Furthermore, unravelling novel molecular characteristics which associate with neuroblastoma tumour progression and cell differentiation was an additional objective. Results: A new strictly defined selection of neuroblastoma tumour spots of highest proliferation activity, hotspots, appeared to be representative and reliable in an analysis of MYCN amplification status using a chromogenic in situ hybridization technique (CISH). Based on the hotspot tumour tissue microarray immunohistochemistry and high-resolution oligo-array-based comparative genomic hybridization, which was integrated with gene expression and in silico analysis of existing transcriptomics, a polysialylated neural cell adhesion molecule (NCAM) and poorly characterized amplicon at 12q24.31 were discovered to associate with outcome. In addition, we found that a previously considered new neuroblastoma treatment target, the mutated c-kit receptor, was not mutated in neuroblastoma samples. Conclusions: Our studies indicate polysialylated NCAM and 12q24.31 amplicon to be new molecular markers with important value in prognostic evaluation of neuroblastoma. Moreover, the presented hotspot tumour tissue microarray method together with the CISH technique of the MYCN oncogene copy number is directly applicable to clinical use. Key words: neuroblastoma, polysialic acid, neural cell adhesion molecule, MYCN, c-kit, chromogenic in situ hybridization, hotspot

Crystallization characteristics of bioactive glasses

Bioactive glasses are excellent candidates for implant materials, because they can form a chemical bond to bone or guide bone growth, depending on the glass composition. Some compositions have even shown soft tissue attachment and antimicrobial effects. So far, most clinical applications are based on monoliths, plates and particulates of different grain sizes. There is a growing interest in special products such as porous implants sintered from microspheres and fibers drawn from preforms or glass melts. The viscosity range at which these are formed coincides with the crystallization temperature range for most bioactive glasses, thus complicating the manufacturing process. In this work, the crystallization tendency and its kinetics for a series of glasses with their compositions within the range of bioactivity were investigated. The factors affecting crystallization and how it is related to composition were studied by means of thermal analysis and hot stage microscopy. The crystal compositions formed during isothermal and non-isothermal heat treatments were analyzed with SEM-EDXA and X-ray diffraction analysis. The temperatures at which sintering and fiber drawing can take place without interfering with crystallization were determined and glass compositions which are suitable for these purposes were established. The bioactivity of glass fibers and partly crystallized glass plates was studied by soaking them in simulated body fluid (SBF). The thickness of silica, calcium and phosphate rich reaction layers on the glass surface after soaking was used as an indication of the bioactivity. The results indicated that the crystallization tendencies of the experimental glasses are strongly dependent on composition. The main factor affecting the crystallization was found to be the alkali oxide content: the higher the alkali oxide content the lower the crystallization temperature. The primary crystalline phase formed at low temperatures in these glasses was sodium calcium silicate. The crystals were found to form through internal nucleation, leading to bulk crystallization. These glasses had high bioactivity in vitro. Even when partially crystalline, they formed typical reaction layers, indicating bioactivity. In fact, sodium calcium silicate crystals were shown to transform in vitro into hydroxyapatite during soaking. However, crystallization should be avoided because it was shown to retard dissolution, bioactivity reactions and complicate fiber drawing process. Glass compositions having low alkali oxide content showed formation of wollastonite crystals on the surface, at about 300°C above the glass transition temperature. The wide range between glass transition and crystallization allowed viscous flow sintering of these compositions. These glasses also withstood the thermal treatments required for fiber drawing processing. Precipitation of calcium and phosphate on fibers of these glasses in SBF suggested that they were osteoconductive. Glasses showing bioactivity crystallize easily, making their hot working challenging. Undesired crystallization can be avoided by choosing suitable compositions and heat treatment parameters, allowing desired product forms to be attained. Small changes in the oxide composition of the glass can have large effects and therefore a thorough understanding of glass crystallization behavior is a necessity for a successful outcome, when designing and manufacturing implants containing bioactive glasses.