Radiosynthesis and use of [18F]F2 derivatives [18F]Selectfluor bis(triflate) and [18F]ClF

Positroniemissiotomografia (PET) on kajoamaton kuvantamismenetelmä, jolla voidaan tutkia biologisia ja farmakologisia prosesseja elävissä ihmisissä ja eläimissä. PET käyttää biologisesti aktiivisia yhdisteitä, joihin on liitetty lyhytikäinen positroni (β+) säteilijä, kuten 18F. Lääketieteellinen fluorikemia perustuu luonnonyhdisteiden tai niiden johdosten fluoraukseen, vaikka luonnonyhdisteissä fluori onkin harvinainen. Fluorin hapetuskyky on korkea, mikä johtaa helposti lämpöä vapauttaviin radikaaliketjureaktioihin ja epätoivottujen sivutuotteiden muodostumiseen. Alkuaine fluorin voimakkaasta reaktiivisuudesta johtuen elektrofiilisessa radiofluorauksessa saavutetaan usein huono paikkaselektiivisyys ja matala saanto. Tästä johtuen elektrofiilisessa radiofluorauksessa on tavoitteena kehittää helpommin käsiteltäviä ja vähemmän reaktiivisia elektrofiilisen fluorin lähteitä, joilla saavutetaan myös parempi paikkaselektiivisyys radiofluorauksessa. [18F]F2:n johdokset, [18F]Selectfluor bis(triflaatti) ([18F]SF) ja [18F]ClF, tehtiin korkealla ominaisaktiivisuudella ja niitä käytettiin malliyhdisteiden elektrofiilisessa synteesissä. Kaksi 6-[18F]FDOPA:n lähtöainetta, tina- ja booriesteriyhdiste, leimattiin käyttäen [18F]SF:a. [18F]NS12137, norepinefriinin kuljettajaproteiini (NET) -selektiivinen PET-merkkiaine, fluorattiin käyttäen kahta elektrofiilista fluorauslähtöainetta, [18F]SF ja [18F]F2, sekä nukleofiilista synteesimenetelmää. [18F]ClF:lleSiirretty Doriast

Cellular differentiation in the inner ear : The role of the network of transcription factors and the Rho GTPase Cdc42

Development of the sensory epithelia of the inner ear and their primary cell types, hair cells and supporting cells, is a complex process under tight molecular regulation. These cells arise from common progenitors that are guided to follow cell-type-specific differentiation program, and undergo prominent structural changes to reach mature morphologies. The mechanisms regulating this cellular differentiation in the developing inner ear are not fully understood. The focus of this thesis has been in understanding the molecular control of the stepwise development of hair cells and supporting cells. Sequential expression of transcription factors has a central role in the control of development of the cells and tissues. Here we show that transcription factor Prox1 participates in the molecular cascade directing cellular differentiation in the inner ear. During early development, Prox1 is expressed in the progenitors of hair cells and supporting cells, and later maintained only in the supporting cells. We found novel interactions between Prox1 and hair cell-specific transcription factors Atoh1, the master regulator of hair cell development, and Gfi1, an essential survival factor of the cochlear hair cells. When overexpressed in hair cells, Prox1 suppressed the expression of Atoh1 and Gfi1, illustrating the possibility of transcriptional reprogramming of hair cells. This downregulation had functional consequences, resulting in auditory hair cell death during a restricted period at late-embryogenesis. Furthermore, when we studied Gfi1-knock-in mice, the model in which auditory hair cells die shortly after differentiation, we found positive interaction between Gfi1 and p57Kip2. Thus, p57Kip2 is introduced as a new candidate to mediate the survival-promoting function of Gfi1 in the auditory hair cells. Rho GTPases integrate signals from different molecular pathways to regulate cell cytoskeleton, intercellular junctions and polarity, all properties that are heavily modulated in the epithelial cells of the developing inner ear. A member of Rho GTPase family, Cdc42, was found to be expressed in the developing auditory sensory epithelium. Analysis of Cdc42 mutant mice revealed a versatile role of this protein, demonstrating its importance in 1) the formation of proper cellular patterning in the auditory sensory epithelium, 2) the regulation of apical-basal and planar polarities of the sensory epithelial cells, and 3) the regulation of apical cytoskeleton in these cells. In the absence of Cdc42, mechanosensory hair bundles at the apices of hair cells failed to develop normally, indicating Cdc42 s significance in hearing function. In addition, Cdc42 regulates the maturation of adherens junctions and apical actin cytoskeleton in postnatal supporting cells. Cdc42-deficient supporting cells lacked the ability for normal wound healing, showing that properly developed apical module is needed for epithelium repair following injury to the hearing organ. This thesis presents new pieces to the molecular network controlling cellular differentiation of the inner ear sensory epithelia. Understanding the regulation of this stepwise development may have therapeutic value. It may help to explain the fundamental reasons why mammalian hair cells do not regenerate and, to identify the mechanisms and factors that could be applied to promote hair cell regeneration in the future.Nisäkkäiden, toisin kuin lintujen ja esimerkiksi sammakkoeläinten, sisäkorvan aistinsolut eivät pysty uusiutumaan kerran tuhouduttuaan ja tämä voi johtaa pysyviin tasapaino- ja kuulohäiriöihin. Tutkimalla sisäkorvan aistinsolujen kehitystä ja sen säätelyä pyritään lisäämään ymmärrystä niistä tekijöistä, jotka toisaalta estävät aistinsolujen uusiutumisen sekä löytämään kohteita, joita manipuloimalla aistinsolujen uusiutumista voitaisiin avittaa. Tässä väitöskirjatyössä on tutkittu sisäkorvan aistinepiteelien solujen erilaistumista ja sen säätelyä keskittyen transkriptiotekijöihin sekä Rho GTP aasi Cdc42:n rooliin. Transkriptiotekijät ovat proteiineja, jotka säätelevät geenien toimintaa, ja Rho GTP aasit ovat proteiineja, jotka yhdessä muiden kohde-proteiinien kanssa säätelevät monia solunsisäisiä, etenkin solutukirankaan liittyviä prosesseja. Työni keskeisimmät tulokset osoittavat, että transkriptiotekijä Prox1 osallistuu yhdessä muiden transkriptiotekijöiden kanssa kaskadiin, joka ohjaa solujen varhaiskehitystä ja Cdc42 puolestaan säätelee merkittävästi solujen rakenteellista erilaistumista. Sisäkorvan aistinepiteelit koostuvat pitkälle erilaistuneista karvasoluista, jotka toimivat varsinaisina aisti-informaation vastaanottajina sekä tukisoluista, jotka muun muassa ylläpitävät aistinepiteelin normaalia toimintaa antamalla rakenteellista tukea. Karva ja tukisolut erilaistuvat yhteisistä esisoluista ja erilaistumisprosessi käynnistyy jo varhain sikiönkehityksen aikana ja sen virheetön läpivienti on edellytys aistinepiteelien normaalille toiminnalle. Tutkimuksessani selvitin, mikä on Prox1:n rooli karva- ja tukisolujen erilaistumisessa. Prox1 ilmentyy varhaisissa karva ja tukisoluissa, ja myöhemmin ainoastaan tukisoluissa. Löysimme, että Prox1 estää karvasoluspesifisten transkriptiotekijöiden Atoh1 ja Gfi1 ilmentymisen kehittyvissä karvasoluissa. Lisäksi havaitsimme, että tämä Gfi1:n ja Atoh1:n puute karvasolujen varhaiskehityksen aikana johtaa solujen kuolemaan, kun taas myöhäisemmässä kehitysvaiheessa karvasolujen selviytyminen ei ollut yhtä riippuvaista näistä tekijöistä. Työn toisessa osassa osoitetaan, että Cdc42 säätelee kuuloaistinepiteelin kehityksen aikana etenkin karva ja tukisolujen oikeanlaista järjestymistä epiteelillä, sekä solujen ja koko epiteelin polariteettia. Oikea polariteetti on merkityksellistä aistinepiteelien toiminnalle. Cdc42:n puuttuessa karvasolujen pinnalla olevat karvakimput myös kehittyvät epänormaalisti. Koska karvakimput ovat karvasolujen toiminnan kannalta keskeisimpiä rakenteita, viittaa tämä siihen, että karvasolujen toiminta aisti-informaation välittäjänä on häiriintynyt. Lisäksi kuuloaistinepiteelin viimeisessä kehitysvaiheessa Cdc42 säätelee etenkin aktiini-tukirangan muodostumista tukisoluissa, vaikuttaen samalla koko aistinepiteelin rakenteeseen. Yhdessä nämä tulokset osoittavat Cdc42:n monimuotoisen ja tärkeän roolin kuuloaistinepiteelin solujen erilaistumisessa toiminnallisiksi soluiksi. Tutkimustietoa sisäkorvan solujen kehityksestä voidaan hyödyntää etsittäessä potentiaalisia terapiamuotoja näiden solujen tuhoutumisesta, tai toiminnallisesta häiriöstä johtuviin sensorisiin ongelmiin

The effect of language-specific characteristics on English and Japanese speakers' ability to recall number information

The current paper presents two experiments investigating the effect of presence versus absence of compulsory number marking in a native language on a speaker’s ability to recall number information from photos. In Experiment 1, monolingual English and Japanese adults were shown a sequence of 110 photos after which they were asked questions about the photos. We found that the English participants showed a significantly higher accuracy rate for questions testing recall for number information when the correct answer was ‘2’ (instead of ‘1’) than Japanese participants. In experiment 2, English and Japanese adults engaged in the same task as in Experiment 1 with an addition that explored reasons for the results found in Experiment 1. The results of Experiment 2 were in line with the results of Experiment 1, but also suggested that the results could not be attributed to differences in guessing patterns between the two groups or the type of linguistic constructions used in the test situations. The current study suggests that native language affects speakers’ ability to recall number information from scenes and thus provides evidence for the Whorfian hypothesis

The Rho GTPase Cdc42 regulates hair cell planar polarity and cellular patterning in the developing cochlea

Hair cells of the organ of Corti (OC) of the cochlea exhibit distinct planar polarity, both at the tissue and cellular level. Planar polarity at tissue level is manifested as uniform orientation of the hair cell stereociliary bundles. Hair cell intrinsic polarity is defined as structural hair bundle asymmetry; positioning of the kinocilium/basal body complex at the vertex of the V-shaped bundle. Consistent with strong apical polarity, the hair cell apex displays prominent actin and microtubule cytoskeletons. The Rho GTPase Cdc42 regulates cytoskeletal dynamics and polarization of various cell types, and, thus, serves as a candidate regulator of hair cell polarity. We have here induced Cdc42 inactivation in the lateembryonic OC. We show the role of Cdc42 in the establishment of planar polarity of hair cells and in cellular patterning. Abnormal planar polarity was displayed as disturbances in hair bundle orientation and morphology and in kinocilium/basal body positioning. These defects were accompanied by a disorganized cell-surface microtubule network. Atypical protein kinase C (aPKC), a putative Cdc42 effector, colocalized with Cdc42 at the hair cell apex, and aPKC expression was altered upon Cdc42 depletion. Our data suggest that Cdc42 together with aPKC is part of the machinery establishing hair cell planar polarity and that Cdc42 acts on polarity through the cellsurface microtubule network. The data also suggest that defects in apical polarization are influenced by disturbed cellular patterning in the OC. In addition, our data demonstrates that Cdc42 is required for stereociliogenesis in the immature cochlea.Peer reviewe

Local changes in computational non-rapid eye movement sleep depth in infants

Objective: Deep NREM sleep and its hallmark EEG phenomenon slow wave activity (SWA) are under homeostatic control in adults. SWA is also locally regulated as it increases in the brain areas that have been used intensively. Moreover, in children, SWA is a marker of cortical maturation. In the present study the local properties of NREM sleep depth were evaluated using the quantitative mean frequency method. We aimed to study if age is related to NREM sleep depth in young infants. In addition, we studied if young infants have local differences in their NREM sleep. Methods: Ambulatory over-night polysomnographies were recorded in 59 healthy and full-term infants at the age of one month. The infants were divided into two age groups (= 44 weeks) to allow maturational evaluations. Results: The quantitative sleep depth analysis showed differences between the age groups. In addition, there were local sleep depth differences within the age groups. Conclusions: The sleep depth change with age is most likely related to cortical maturation, whereas the local sleep depth gradients might also reflect the use-dependent properties of SWA. (C) 2017 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.Peer reviewe

Radiosynthesis of the norepinephrine transporter tracer [F-18]NS12137 via copper-mediated F-18-labelling

[F-18]NS12137 (exo-3-[(6-[F-18]fluoro-2-pyridyl)oxy]8-azabicyclo[3.2.1]octane) is a highly selective norepinephrine transporter (NET) tracer. NETs are responsible for the reuptake of norepinephrine and dopamine and are linked to several neurodegenerative and neuropsychiatric disorders. The aim of this study was to develop a copper-mediated F-18-fluorination method for the production of [F-18]NS12137 with straightforward synthesis conditions and high radiochemical yield and molar activity. [F-18]NS12137 was produced in two steps. Radiofluorination of [F-18]NS12137 was performed via a copper-mediated pathway starting with a stannane precursor and using [F-18]F- as the source of the fluorine-18 isotope. Deprotection was performed via acid hydrolysis. The radiofluorination reaction was nearly quantitative as was the deprotection based on HPLC analysis. The radiochemical yield of the synthesis was 15.1 +/- 0.5%. Molar activity of [F-18]NS12137 was up to 300 GBq/mu mol. The synthesis procedure is straightforward and can easily be automated and adapted for clinical production

Maternal asthma is associated with increased risk of perinatal mortality

Background Asthma is the most common chronic disease during pregnancy and it may have influence on pregnancy outcome. Objectives Our goal was to assess the association between maternal asthma and the perinatal risks as well as possible effects of asthma medication. Methods The study was based on a nationwide Finnish register-based cohort between the years 1996 and 2012 in the Drug and Pregnancy Database. The register data comprised 962 405 singleton live and stillbirths, 898 333 (93.3%) pregnancies in mothers with neither confirmed asthma nor use of asthma medication (controls), and 26 674 (2.8%) pregnancies with confirmed maternal asthma. 71% of mothers with asthma used asthma medication. The diagnosis of asthma was based on the mothers' right for subsidised medication which is carefully evaluated by strict criteria including pulmonary function testing. Odds ratio was used in comparison. Premature birth (PB), low birth weight, small for gestational age (SGA), neonatal death were the main outcome measures. Results Maternal asthma was associated with adjusted odds ratios (aORs) for perinatal mortality 1.24 (95% CI 1.05 to 1.46), preterm birth 1.18 (1.11 to 1.25), low birth weight 1.29 (1.21 to 1.37), fetal growth restriction (SGA) 1.32, (1.24 to 1.40), and asphyxia 1.09 (1.02 to 1.17). Asthma treatment reduced the increased risk of preterm birth aOR 0.85 (95% CI 0.76 to 0.96) but mothers with treated asthma had higher risks of fetal growth restriction (SGA) aOR 1.26 (1.10 to 1.45), and asphyxia aOR 1.37 (1.17 to 1.61) than mothers with untreated asthma. Conclusion Asthma is associated with increased risks of perinatal mortality, preterm birth, low birth weight, fetal growth restriction (SGA), and asphyxia. Asthma treatment reduces the risk of preterm delivery, but it does not seem to reduce other complications such as perinatal mortality.Peer reviewe

Fast and efficient copper-mediated 18F-fluorination of arylstannanes, aryl boronic acids, and aryl boronic esters without azeotropic drying

BackgroundCopper-mediated radiofluorination is a straightforward method to produce a variety of [18F]fluoroarenes and [18F]fluoroheteroarenes. To minimize the number of steps in the production of 18F-labelled radiopharmaceuticals, we have developed a short and efficient azeotropic drying-free 18F-labelling method using copper-mediated fluorination. Our goal was to improve the copper-mediated method to achieve wide substrate scope with good radiochemical yields with short synthesis time.ResultsSolid phase extraction with Cu (OTf)2 in dimethylacetamide is a suitable activation method for [18F]fluoride. Elution efficiency with Cu (OTf)2 is up to 79% and radiochemical yield (RCY) of a variety of model molecules in the crude reaction mixture has reached over 90%. Clinically relevant molecules, norepinephrine transporter tracer [18F]NS12137 and monoamine transporter tracer [18F]CFT were produced with 16.5% RCY in 98 min and 5.3% RCY in 64 min, respectively.ConclusionsCu (OTf)2 is a suitable elution agent for releasing [18F]fluoride from an anion exchange cartridge. The method is fast and efficient and the Cu-complex is customizable after the release of [18F]fluoride. Alterations in the [18F]fluoride elution techniques did not have a negative effect on the subsequent labelling reactions. We anticipate this improved [18F]fluoride elution technique to supplant the traditional azeotropic drying of [18F]fluoride in the long run and to concurrently enable the variations of the copper-complex.</div

UriSed 3 PRO automated microscope in screening bacteriuria at region-wide laboratory organization

Background and aims: We assessed the possibility to rule out negative urine cultures by counting with UriSed 3 PRO (77 Elektmnika, Hungary) at Helsinki and Uusimaa Hospital District. Materials and methods: Bacteria counting of the UriSed 3 PRO automated microscope was verified with reference phase contrast microscopy against growth in culture. After acceptance into routine, results of bacteria and leukocyte counting from 56 426 specimens with eight UriSed 3 PRO instruments were compared against results from parallel samples cultured on chromogenic agar. Laboratory data including preanalytical details were accessed through the regional database of the Helsinki and Uusimaa Hospital District. Results: A combined sensitivity of 87-92% and a negative predictive value of 90-96% with a specificity of 54-50% was reached, depending on criteria. Preanalytical data (incubation time in bladder) combined with the way of urine collection would improve these figures if reliable. Conclusions: Complex patient populations, regional logistics and data interfases, and economics related to increased costs of additional particle counts against costs of screening cultures of all samples, did not support adaptation of a screening process of urine cultures. This conclusion was made locally, and may not be valid elsewhere.Peer reviewe

Cdc42-dependent structural development of auditory supporting cells is required for wound healing at adulthood

Peer reviewe