Neuronal RARβ signaling modulates PTEN activity directly in neurons and via exosome transfer in astrocytes to prevent glial scar formation and induce spinal cord regeneration

Failure of axonal regeneration in the central nervous system (CNS) is mainly attributed to a lack of intrinsic neuronal growth programs and an inhibitory environment from a glial scar. Phosphatase and tensin homolog (PTEN) is a major negative regulator of neuronal regeneration and, as such, inhibiting its activity has been considered a therapeutic target for spinal cord (SC) injuries (SCIs). Using a novel model of rat cervical avulsion, we show that treatment with a retinoic acid receptor β (RARβ) agonist results in locomotor and sensory recovery. Axonal regeneration from the severed roots into the SC could be seen by biotinylated dextran amine labeling. Light micrographs of the dorsal root entry zone show the peripheral nervous system (PNS)–CNS transition of regrown axons. RARβ agonist treatment also resulted in the absence of scar formation. Mechanism studies revealed that, in RARβ-agonist-treated neurons, PTEN activity is decreased by cytoplasmic phosphorylation and increased secretion in exosomes. These are taken up by astrocytes, resulting in hampered proliferation and causing them to arrange in a normal-appearing scaffold around the regenerating axons. Attribution of the glial modulation to neuronal PTEN in exosomes was demonstrated by the use of an exosome inhibitor in vivo and PTEN siRNA in vitro assays. The dual effect of RARβ signaling, both neuronal and neuronal–glial, results in axonal regeneration into the SC after dorsal root neurotmesis. Targeting this pathway may open new avenues for the treatment of SCIs. SIGNIFICANCE STATEMENT Spinal cord injuries (SCIs) often result in permanent damage in the adult due to the very limited capacity of axonal regeneration. Intrinsic neuronal programs and the formation of a glial scar are the main obstacles. Here, we identify a single target, neuronal retinoic acid receptor β (RARβ), which modulates these two aspects of the postinjury physiological response. Activation of RARβ in the neuron inactivates phosphatase and tensin homolog and induces its transfer into the astrocytes in small vesicles, where it prevents scar formation. This may open new therapeutic avenues for SCIs

COX-2 inhibition by diclofenac is associated with decreased apoptosis and lesion area after experimental focal penetrating traumatic brain injury in rats

Traumatic brain injury (TBI) is followed by a secondary inflammation in the brain. The inflammatory response includes prostanoid synthesis by the inducible enzyme cyclooxygenase-2 (COX-2). Inhibition of COX-2 is associated with improved functional outcome in experimental TBI models, although central nervous system-specific effects are not fully understood. Animal studies report better outcomes in females than males. The exact mechanisms for this gender dichotomy remain unknown. In an initial study we reported increased COX-2 expression in male rats, compared to female, following experimental TBI. It is possible that COX-2 induction is directly associated with increased cell death after TBI. Therefore, we designed a sequential study to investigate the blocking of COX-2 specifically, using the established COX-2 inhibitor diclofenac. Male Sprague-Dawley rats weighing between 250 and 350 g were exposed to focal penetrating TBI and randomly selected for diclofenac treatment (5 ?g intralesionally, immediately following TBI) (n = 8), controls (n = 8), sham operation (n = 8), and normal (no manipulation) (n = 4). After 24 h, brains were removed, fresh frozen, cut into 14?m coronal sections and subjected to COX-2 immunofluorescence, Fluoro Jade, TUNEL, and lesion area analyses. Diclofenac treatment decreased TUNEL staining indicative of apoptosis with a mean change of 54% (p 0.05) and lesion area with a mean change of 55% (p 0.005). Neuronal degeneration measured by Fluoro Jade and COX-2 protein expression levels were not affected. In conclusion, COX-2 inhibition by diclofenac was associated with decreased apoptosis and lesion area after focal penetrating TBI and may be of interest for further studies of clinical applications

Kalkkitehtaan pienjänniteverkon oikosulkuvirtalaskelmat

Opinnäytetyön tarkoituksena oli tehdä laskelmat SMA Mineral Oy:n Tornion Röyttässä sijaitsevaan kalkkitehtaan pienjännitejakeluverkon oikosulkuvirroille. Opinnäytetyön toimeksiantajana oli Tiltek Engineering Oy. Työssä esiteltiin yleisesti teollisuusverkoille ominaispiirteitä sähkönjakelussa, sulakkeettonta järjestelmää ja lyhyesti Tiltek Engineering Oy:n sekä SMA Mineral Oy:n toimintaa. Tarkastelussa oli myös virtaa rajoittavat komponentit. Opinnäytetyö rajattiin laskennan suhteen pienjännitejakelukeskukselta lähtevien pääkeskuksien lähtökiskostoille. Työssä tehtiin pienjännitejakeluverkon mallintaminen lähtötietojen perusteella, pääkeskuksille tulevien kaapeleiden määrittelyt ja oikosulkuvirtalaskennat pääkeskuksien lähtöihin asti. Oikosulkuvirtojen laskentaan ja jakeluverkon mallintamiseen käytettiin Schneider Electricin Ecodial Advance Calculation -ohjelmaa. Ohjelman rinnalle otettiin myös laskentamenetelmiksi käsin laskenta ja Excel-laskenta lisäämään tulosten luotettavuutta ja vertailukelpoisuutta. Käsin laskennat ja Excel-laskennat toteutettiin käyttämällä Thevenin menetelmää. Työstä saatavat virta-arvot ovat tärkeitä prosessin toteutuksen, sähköverkon suojauksien toimivuuden ja tulevien laajennuksien suunnittelujen kannalta. Saatavat laskenta-arvot täydentävät olemassa olevia virtalaskelmia ja varmentavat suojalaitteiden asettelut verkon nykytilanteelle sopiviksi. Laajempi vikavirtojen laskenta ja pienjännitejakeluverkon mallintaminen haluttiin jättää mahdollisesti seuraavalle opinnäytetyön tekijälle.The subject at of this final project was to model and calculate short-circuit fault currents in 0,4 kV network for SMA Mineral Oy Röyttä calcium factory which is located in Tornio. The topic was given by Tiltek Engineering Oy. The main part of the theory is about electricity distribution for factories electricity and the meaning of nonfused system in low voltage network. The theory part also contains essential information about both companies: SMA Mineral Oy and Tiltek Engineering Oy. The thesis was outlined to make calculations and simulations from low voltage distribution center to the secondary poles of the switchboard. The practical part of the work was creating network modelling, defining the effect of the components in network and calculating three phase short circuit fault currents. Simulations were made by using Schneider Electric Ecodial Advanced Calculation software which is an electric network calculation software. The calculations were made by software, Excel and also manually by hand to increase the reliability of the calculation results. The results can be compared together because the calculations are made based on Theven’s theorem. The short circuit current results are very valuable knowledge for a successful protection and they complement the already existing current calculations. The results also offer necessary information for planning enlargement projects. In the future, this project can be continued easily by another final project writer

Alaraajan nivelten liikelaajuuksien yhteydet kävelyn biomekaniikkaan CP-vammaisilla lapsilla ja nuorilla

Kävely on ihmisen yksi yleisimmistä liikkumismuodoista ja oppimisen jälkeen siitä tulee lähes automaattista. Kävelystä voidaan mitata useita biomekaanisia muuttujia, joiden avulla voidaan laskennallisesti määrittää mitä ihmisen kävelyssä tapahtuu. Kävelyanalyysia käytetään usein vahvistamaan lääketieteellisiä diagnooseja liikunnallisista rajoitteista auttamaan esimerkiksi polvivamman kuntoutuksessa. Tämän tutkielman tarkoituksena oli tutkia spastisilta CP-vammaisilta lapsilta ja nuorilta passiivisesti mitattujen ja kävelyn aikana mitattujen nilkka-, polvi- ja lantionivelien liikelaajuuksien välistä yhteyttä ja niiden muutoksia 9 kuukauden tutkimuksen aikana. Tutkimus on osa EXECP-tutkimusta, jossa tutkittiin yksilöllisesti suunnitellun 3 kuukauden liikunnallisen intervention vaikutusta CP-vammaisten lasten ja nuorten toimintakykyyn ja her-molihasjärjestelmän mekanismeihin. Tutkimukseen rekrytoitiin 8 CP-vammaista (9-24 vuotta) ja sukupuolen ja iän puolesta vastaava verrokkiryhmä. Mittaukset toteutettiin kaksi kertaa ennen interventiota kolmen kuukauden välein ja kaksi kertaa intervention jälkeen. Mittaukset sisälsivät alaraajojen passiivisen liikkuvuuden arvioinnin ja 3D-liikeanalyysin. Tämän tutkimuksen tuloksista ei löydetty korrelaatioita eikä tilastollisesti merkitseviä eroja passiivisten ja kävelyn aikaisten mitattujen nivelten liikelaajuuksien välillä. Tämä havainto koskee sekä CP-vammaisia ja verrokkiryhmää. Intervention ja 3 kuukauden kontrolliajan muu-tokset olivat pieniä, esimerkiksi lonkkanivelen passiivisessa ojennuksessa muutos oli +1,1% intervention seurauksena, mutta kontrolliajan jälkeen liikelaajuus laski 15% intervention tulokseen nähden ja -14% lähtötasoon nähden. Verrokkiryhmän mittauksissa ajan vaikutukselle ei löydetty tilastollisesti merkitsevää eroa, joten kahden mittauksen keskiarvotuloksia verrattiin CP-vammaisten tuloksiin. Kävelyn aikaisten liikelaajuuksien ei havaittu tilastollisesti merkitsevästi kasvaneen liikunnallisen intervention seurauksena. CP-vammaisten askelsyklin pituuden (r = 0,995) ja askelnopeuden (r = 0,816) väliltä havaittiin tilastollisesti merkittäviä korrelaatioi-ta, mutta yhteydet olivat havaittavissa pelkästään ajan vaikutuksen seurauksena. Tuloksista voidaan päätellä, että passiiviset nivelten liikelaajuudet eivät toimi selittävänä tekijänä kävelyn aikaisiin nivelten liikelaajuuksiin. Pelkkiä kinemaattisia muuttujia tarkasteltaessa tämän tutkimuksen menetelmin ei ole löydettävissä yhteyksiä passiivisten liikelaajuuksien ja kävelyn aikaisten liikelaajuuksien välille.Walking is one of the most common movements of human locomotion and after learning it becomes almost automatic. During the gait, several biomechanical variables can be measured to determine how and why a person walks in this way. Gait analysis is often used to confirm medical diagnoses of physical disabilities, in athlete’s movement analysis and to help, for ex-ample, rehabilitate knee injuries. The purpose of this thesis was to study the correlations be-tween passively and during the gait measured lower limb joint’s range of motion in cerebral palsy spastica. And investigate how the biomechanics of gait correlate to range of motion. This research is part of EXECP-study and the purpose of that study is to investigate the effect of individually tailored, 3 months long exercise intervention on physical capacity and func-tion, neuromuscular mechanisms and cardiometabolic risk factors of children and young adults with cerebral palsy. The aim of study was to evaluate the effects of the intervention to spastic-ity. In this study were recruited 8 CP (9 to 24 years) and a control group of typically devel-oped age and sex-matched participants. Tests were split to five times in the study: three times before and two times after the intervention. Measurements of tests included passively meas-ured lower limbs range of motion and 3D gait analysis. The results showed that there is no significant correlation between lower limb passively and actively measured joint’s range of motion. This finding appears in both groups, CP and control group. For example in CP group the passive hip extension increased 1,1% between baseline and after the intervention but decreased 15% after the three month’s follow-up results com-pare to after intervention and as much as -13,5% when compared to baseline results. In control group time differences did not affect any at all so the pre-measurements could be calculated to one group with mean values of both measurements. During the gait measured joint’s range of motion did not significantly change after the exercise intervention. Additionally, the stride length (r = 0,995) and step speed (r = 0,816) showed the association during the time in CP group. Thus, the association disappeared after the exercise intervention

Injury threshold for sagittal plane rotational induced diffuse axonal injuries

Sagittal plane rotational acceleration induced diffuse axonal injury threshold was investigated using an animal model in which the heads of the rats were exposed to selected rotation accelerations. Post-trauma survival times ranged from 3 to 120 h. Numerous S100 serum concentrations, brain tissue stained for β-Amyloid Precursor Protein (β-APP), and probes for Cyclooxygenase 2 (COX2) mRNA were used to detect affected nerve cells, decaying axons, and cytoskeletal changes, respectively. Scaling laws were applied to estimate injury thresholds for the human brain. Confocal imaging revealed bands of β-APP-positive axons in the corpus callosum and its edges in animals exposed to rotational accelerations >1.1 Mrad/s2. Similarly, for COX2 presence and S100 concentrations at >0.9 Mrad/s2, the numbers of stained cells in the cortex and hippocampus and the concentrations increased. The data clearly indicate that the rat brain is injured at a specific rotational acceleration. Scaled to that of humans this would be 10 krad/s2 with a duration of 4 ms

Effect of age on amount and distribution of diffuse axonal injury after rotational trauma

Injury thresholds for diffuse axonal injuries (DAI) due to rotational head trauma are being developed. However, age may influence injury risk. Understanding this relationship is necessary for the development of injury criteria for children and elderly. Here rats were exposed to sagittal plane rotational acceleration head trauma and the outcome studied using Amyloid Precursor Protein to detect axonal injuries. For relatively young animals, DAI were found in and along the border of the corpus callosum and in the brainstem when rotational acceleration exceeded 1.1 Mrad/s2. Slightly older animals required higher accelerations to exhibit similar injury levels and the injury patterns were different. In conclusion, a previous study showed that the onset of diffuse axonal injuries started to appear at 10 krad/s2 with a duration of 4 ms, when scaled for humans, whereas new data indicate that this onset is slightly higher for occupants thata atre approximately 15 years older

Effect of age on amount and distribution of diffuse axonal injury after rotational trauma

Traumatic brain injuries (TBI) are a major public health problem in term of suffering and cost for society. About 40% of the TBI patients admitted to hospitals are non-focal injuries, usually referred to as distributed brain injuries (DBI). Studies have hypothesized that the resulting strains in the brain tissue are the primary cause of neurological deficiencies following DBI. These strains commonly appear when the skull is accelerated and the brain mass, due to its inertia, lags behind or continues its motion relative the skull. It has been suggested that the severity of the injury correlates with the amplitude of the angular acceleration, or with the resulting angular velocity. Among DBI, diffuse axonal injury (DAI) is common and regularly results in unconsciousness or death. Past studies have suggested DAI injury criteria and thresholds that can be used with crash test dummies and mathematical models of the human. However, these past studies have been performed with rather young animals. In addition, some studies have shown that brain properties change as we grow older; it is likely that this have an effect on the risk of DAI following a rotational head injury. Therefore, the aim of this study is to investigate the distribution of axonal injuries in the brain following sagittal plane rotation trauma and to determine if the injury threshold changes when the subjects grow older. In this study rats were exposed to sagittal plane rotational acceleration head trauma and the outcome studied using Amyloid Precursor Protein to detect axonal injuries. For relatively young animals, DAI were found in and along the border of the corpus callosum and in the brainstem when rotational acceleration exceeded 1.1 Mrad/s2. Slightly older animals required higher accelerations to exhibit similar injury levels and the injury patterns were different. We hypothesise that the lower injury scores for the older subjects could be due to differences in tolerance to tissue strains or, as indicated in the literature, that the differences were due to changes in the constitutive properties of the brain tissue. The latter suggests, in combination with the observed differences between older and younger individuals, that additional studies on brain tissue properties, and studies on rotational acceleration induced DAI, should be carried out using even younger and older animals than used in this study. In conclusion, a previous study showed that the onset of diffuse axonal injuries started to appear at 10 krad/s2 with a duration of 4 ms, when data were scaled for humans, whereas new data indicate that this onset is slightly higher for occupants that are approximately 15 years older

Effect of age on amount and distribution of diffuse axonal injury after rotational trauma

Injury thresholds for diffuse axonal injuries (DAI) due to rotational head trauma are being developed. However, age may influence injury risk. Understanding this relationship is necessary for the development of injury criteria for children and elderly. Here rats were exposed to sagittal plane rotational acceleration head trauma and the outcome studied using Amyloid Precursor Protein to detect axonal injuries. For relatively young animals, DAI were found in and along the border of the corpus callosum and in the brainstem when rotational acceleration exceeded 1.1 Mrad/s2. Slightly older animals required higher accelerations to exhibit similar injury levels and the injury patterns were different. In conclusion, a previous study showed that the onset of diffuse axonal injuries started to appear at 10 krad/s2 with a duration of 4 ms, when scaled for humans, whereas new data indicate that this onset is slightly higher for occupants thata atre approximately 15 years older