998 resultados para calcium signals integration
Resumo:
Mutations in GDAP1, which encodes protein located in the mitochondrial outer membrane, cause axonal recessive (AR-CMT2), axonal dominant (CMT2K) and demyelinating recessive (CMT4A) forms of Charcot-Marie-Tooth (CMT) neuropathy. Loss of function recessive mutations in GDAP1 are associated with decreased mitochondrial fission activity, while dominant mutations result in impairment of mitochondrial fusion with increased production of reactive oxygen species and susceptibility to apoptotic stimuli. GDAP1 silencing in vitro reduces Ca2+ inflow through store-operated Ca2+ entry (SOCE) upon mobilization of endoplasmic reticulum (ER) Ca2+, likely in association with an abnormal distribution of the mitochondrial network. To investigate the functional consequences of lack of GDAP1 in vivo, we generated a Gdap1 knockout mouse. The affected animals presented abnormal motor behavior starting at the age of 3 months. Electrophysiological and biochemical studies confirmed the axonal nature of the neuropathy whereas histopathological studies over time showed progressive loss of motor neurons (MNs) in the anterior horn of the spinal cord and defects in neuromuscular junctions. Analyses of cultured embryonic MNs and adult dorsal root ganglia neurons from affected animals demonstrated large and defective mitochondria, changes in the ER cisternae, reduced acetylation of cytoskeletal α-tubulin and increased autophagy vesicles. Importantly, MNs showed reduced cytosolic calcium and SOCE response. The development and characterization of the GDAP1 neuropathy mice model thus revealed that some of the pathophysiological changes present in axonal recessive form of the GDAP1-related CMT might be the consequence of changes in the mitochondrial network biology and mitochondria-endoplasmic reticulum interaction leading to abnormalities in calcium homeostasis.
Horizontal transfer of exosomal microRNAs transduce apoptotic signals between pancreatic beta-cells.
Resumo:
BACKGROUND: Diabetes mellitus is a common metabolic disorder characterized by dysfunction of insulin-secreting pancreatic beta-cells. MicroRNAs are important regulators of beta-cell activities. These non-coding RNAs have recently been discovered to exert their effects not only inside the cell producing them but, upon exosome-mediated transfer, also in other recipient cells. This novel communication mode remains unexplored in pancreatic beta-cells. In the present study, the microRNA content of exosomes released by beta-cells in physiological and physiopathological conditions was analyzed and the biological impact of their transfer to recipient cells investigated. RESULTS: Exosomes were isolated from the culture media of MIN6B1 and INS-1 derived 832/13 beta-cell lines and from mice, rat or human islets. Global profiling revealed that the microRNAs released in MIN6B1 exosomes do not simply reflect the content of the cells of origin. Indeed, while a subset of microRNAs was preferentially released in exosomes others were selectively retained in the cells. Moreover, exposure of MIN6B1 cells to inflammatory cytokines changed the release of several microRNAs. The dynamics of microRNA secretion and their potential transfer to recipient cells were next investigated. As a proof-of-concept, we demonstrate that if cel-miR-238, a C. Elegans microRNA not present in mammalian cells, is expressed in MIN6B1 cells a fraction of it is released in exosomes and is transferred to recipient beta-cells. Furthermore, incubation of untreated MIN6B1 or mice islet cells in the presence of microRNA-containing exosomes isolated from the culture media of cytokine-treated MIN6B1 cells triggers apoptosis of recipient cells. In contrast, exosomes originating from cells not exposed to cytokines have no impact on cell survival. Apoptosis induced by exosomes produced by cytokine-treated cells was prevented by down-regulation of the microRNA-mediating silencing protein Ago2 in recipient cells, suggesting that the effect is mediated by the non-coding RNAs. CONCLUSIONS: Taken together, our results suggest that beta-cells secrete microRNAs that can be transferred to neighboring beta-cells. Exposure of donor cells to pathophysiological conditions commonly associated with diabetes modifies the release of microRNAs and affects survival of recipient beta-cells. Our results support the concept that exosomal microRNAs transfer constitutes a novel cell-to-cell communication mechanism regulating the activity of pancreatic beta-cells.
Resumo:
Diplomityö tehtiin Partek Oyj Abp:lle antamaan IT-järjestelmistä vastuussa oleville ja niihin tukeutuville johtohenkilöille yleisnäkemys IT-sovellusintegroinnista sekä luomaan ohjeet integrointi projekteihin. Diplomityön alkuosassa esitellään liiketoiminnan prosessien pulmakohtia ja sovellusintegrointien liiketoiminnalle tuomia etuja yleisellä tasolla perustuen kirjallisuuteen. Yleisen tason etuja saadaan mm. nopeampien prosessien, paremman tiedon saatavuuden ja ihmisille tulevien uusien toimintatapojen kautta tulevista eduista. Työn seuraavassa osiossa esitellään mitä sovellusintegraatio tarkoittaa käytännössä, mitä erilaisia vaihtoehtoja integroinneille on ja mitä etuja ja haittoja erilaisista integrointitavoista on. Integrointitavoista viesti-pohjainen integrointitapa on noussut suosituimmaksi sen yksinkertaisuuden, luotettavuuden ja helpon liitettävyyden takia. Integrointisovelluksilla on mahdollista siirtää, muokata, prosessoida ja varastoida viestejä. Näiden ominaisuuksien avulla on mahdollista luoda reaaliaikaisia yhteistyöverkostoja. Tämä osio perustuu kirjallisuuteen , artikkeleihin ja haastatteluihin. Kolmas osio keskittyy integrointi projektin ominaispiirteisiin luoden toimintakartan integrointiprojektin kululle. Osiossa esitellään huomioitavat tekniset asiat, kustannukset ja edut sekä mallipohjia integroinnin dokumentointiin. Osio perustuu omiin kokemuksiin, haastatteluihin sekä kirjallisuuteen. Neljännessä osiossa esitellään Partekissa tehty integrointiprojekti. Integrointityö tehtiin ostajille tarkoitetun toimittajarekisterin (PPM) ja ERP-järjestelmän (Baan) välillä. Integrointiin käytettiin yhtä suosituinta integrointityökalua nimeltään IBM WebSphere MQ.Osio perustuu projektin dokumentointiin, omiin kokemuksiin ja kirjallisuuteen. Diplomityön päättää yhteenveto. Kolme pääetua voidaan saavuttaa integroinneilla ja toimintakartalla; tiedon luotettavuus paranee, toimintakartalla saadaan integroinneille malli ja luodaan riippumattomuutta tiettyihin avain henkilöihin tarkalla dokumentoinnilla ja toimintatapojen standardoinnilla.
Resumo:
In The Cognitive-Emotional Brain, Pessoa (2013) suggests that cognition and emotion should not be considered separately. We agree with this and argue that cognitive architectures can provide steady ground for this kind of theory integration and for investigating interactions among underlying cognitive processes. We briefly explore how affective components can be implemented and how neuroimaging measures can help validate models and influence theory development.
Resumo:
In this paper we design and develop several filtering strategies for the analysis of data generated by a resonant bar gravitational wave (GW) antenna, with the goal of assessing the presence (or absence) therein of long-duration monochromatic GW signals, as well as the eventual amplitude and frequency of the signals, within the sensitivity band of the detector. Such signals are most likely generated in the fast rotation of slightly asymmetric spinning stars. We develop practical procedures, together with a study of their statistical properties, which will provide us with useful information on the performance of each technique. The selection of candidate events will then be established according to threshold-crossing probabilities, based on the Neyman-Pearson criterion. In particular, it will be shown that our approach, based on phase estimation, presents a better signal-to-noise ratio than does pure spectral analysis, the most common approach.
Resumo:
Galanin receptor (GalR) subtypes 1-3 linked to central galanin neurons may form heteromers with each other and other types of G protein-coupled receptors in the central nervous system (CNS). These heteromers may be one molecular mechanism for galanin peptides and their N-terminal fragments (gal 1-15) to modulate the function of different types of glia-neuronal networks in the CNS, especially the emotional and the cardiovascular networks. GalR-5-HT1A heteromers likely exist with antagonistic GalR-5-HT1A receptor-receptor interactions in the ascending midbrain raphe 5-HT neuron systems and their target regions. They represent a novel target for antidepressant drugs. Evidence is given for the existence of GalR1-5-HT1A heteromers in cellular models with trans-inhibition of the protomer signaling. A GalR1-GalR2 heteromer is proposed to be a galanin N-terminal fragment preferring receptor (1-15) in the CNS. Furthermore, a GalR1-GalR2-5-HT1A heterotrimer is postulated to explain why only galanin (1-15) but not galanin (1-29) can antagonistically modulate the 5-HT1A receptors in the dorsal hippocampus rich in gal fragment binding sites. The results underline a putative role of different types of GalR-5-HT1A heteroreceptor complexes in depression. GalR antagonists may also have therapeutic actions in depression by blocking the antagonistic GalR-NPYY1 receptor interactions in putative GalR-NPYY1 receptor heteromers in the CNS resulting in increases in NPYY1 transmission and antidepressant effects. In contrast the galanin fragment receptor (a postulated GalR1-GalR2 heteromer) appears to be linked to the NPYY2 receptor enhancing the affinity of the NPYY2 binding sites in a putative GalR1-GalR2-NPYY2 heterotrimer. Finally, putative GalR-α2-adrenoreceptor heteromers with antagonistic receptor-receptor interactions may be a widespread mechanism in the CNS for integration of galanin and noradrenaline signals also of likely relevance for depression
Resumo:
Diplomityön tarkoituksena oli arvioida akvisition jälkeistä integraatioprosessia. Integraation tarkoitus on mukauttaa ostettu yritys toimivaksi osaksi konsernia. Työn empiirisenä ongelmana oli yleisesti tunnustettu integraatiojohtamisen kompleksisuus. Samoin myöskin akateemisesta kirjallisuudesta puuttui koherentti malli, jolla arvioida integraatiota. Tutkimuskohteena oli akvisitio, jossa suomalainen tietotekniikkan suuryritys osti osake-enemmistön tsekkiläisestä keskisuuresta ohjelmistoyrityksestä. Tutkimuksessa generoitiin integraatiojohtamisen malli tietopohjaiseen organisaatioon. Mallin mukaan integraatio koostuu kolmesta eriävästä, mutta toisiaan tukevasta alueesta: organisaatiokulttuurin yhdentyminen, tietopääoman tasaaminen ja konsernin sisäisten prosessien yhdenmukaistaminen. Näistä kaksi kaksi jälkimmäistä ovat johdettavissa, mutta kulttuurin yhdentymiseen integraatiojohtamisella voidaan vaikuttaa vain katalysoivasti. Organisaatiokulttuuri levittäytyy vain osallisten vuorovaikuksien kautta. Lisäksi tutkimus osoitti, miten akvisitio on revolutionaarinen vaihe yrityksen kehityksessä. Integraation ensimmäinen ajanjakso on revolutionaarista. Tällöin suurimmat ja näkyvimmät johdettavat muutokset pyritään saamaan aikaan, jotta integraatiossa edettäisiin evolutionaariseen kehitykseen. Revolutionaarisen intergaation vetojuhtana toimii integraatiojohto, kun taas evolutionaarinen integraatio etenee osallisten (organisaation jäsenten) itsensä toiminnan ja vuorovaikutusten kautta.
Resumo:
Tämän tutkielman tavoitteena on perehtyä globaalin yrityksen laskentatoimen tietojärjestelmien yhtenäistämiseen ja käyttöönottoon esimerkkinä UPM-Kymmene konsernin projekti. Tutkielmassa sovelletaan hermeneuttista tutkimusotetta. Teoreettisesti aihetta tarkastellaan globalisoitumisen ja laskentatoimen tietojärjestelmille asetettavien vaatimusten pohjalta, sekä järjestelmän muutosprosessin eri vaiheissa huomioon otettavien muuttujien perusteella. Yhtenäisen laskentatoimen tietojärjestelmän tuomat edut globaalille yritykselle ovat ilmeisiä. Ennen yhtenäisen projektin kehittelyä on olennaista tutkia lähtökohdat projektin onnistumiselle ja suunnitella projektin eri vaiheet huolella. Tutkielmassa havaitaan myös, että globaalissa yrityksessä tulee huomioida eri yrityskulttuurit sekä tulosyksiköiden erilaiset toimintatavat. Johtopäätöksenä todetaan, että sekä yritysjohdon että tulosyksiköiden sitoutuneisuus projektiin ja yhtenäiset tavoitteet ovat oleellisia projektin onnistumisen kannalta.
Resumo:
The improvement of the reliability of the contact between the osseous tissues and the implant materials has been tested by recovering the metallic implants with ceramic materials, usually calcium phosphates. In our study, the calcium phosphate recovering layers were deposited by means of a pulsed-laser deposition technique. Our aim was to to evaluate the tissue interactions established between cortical bone and titanium implants covered by five different layers, ranging from amorphous calcium phosphate to crystalline hydroxyapatite, obtained by altering the parameters of the laser ablation process. The surgical protocol of the study consisted in the simultaneous implantation of the five types of implants in both the tibial dyaphisis of three Beagle dogs, sacrificed respectively one, two and three months after the last surgical procedures. After the sacrifice, the samples were submitted to a scheduled procedure of embedding in plastic polymers without prior decalcification, in order to perform the ultrastructural studies: scanning microscopy with secondary and backscattered electrons (BS-SEM). Our observations show that both in terms of the calcified tissues appearing as a response to the presence of the different coatings and of time of recovering, the implants coated with crystalline calcium phosphate layers by laser ablation present a better result than the amorphous-calcium-phosphate-coated implants. Moreover, the constant presence of chondroid tissue, related with the mechanical induction by forces applied on the recovering area, strongly suggests that the mechanisms implied in osteointegration are related to endomembranous, rather than endochondral ossification processes
Resumo:
The improvement of the reliability of the contact between the osseous tissues and the implant materials has been tested by recovering the metallic implants with ceramic materials, usually calcium phosphates. In our study, the calcium phosphate recovering layers were deposited by means of a pulsed-laser deposition technique. Our aim was to to evaluate the tissue interactions established between cortical bone and titanium implants covered by five different layers, ranging from amorphous calcium phosphate to crystalline hydroxyapatite, obtained by altering the parameters of the laser ablation process. The surgical protocol of the study consisted in the simultaneous implantation of the five types of implants in both the tibial dyaphisis of three Beagle dogs, sacrificed respectively one, two and three months after the last surgical procedures. After the sacrifice, the samples were submitted to a scheduled procedure of embedding in plastic polymers without prior decalcification, in order to perform the ultrastructural studies: scanning microscopy with secondary and backscattered electrons (BS-SEM). Our observations show that both in terms of the calcified tissues appearing as a response to the presence of the different coatings and of time of recovering, the implants coated with crystalline calcium phosphate layers by laser ablation present a better result than the amorphous-calcium-phosphate-coated implants. Moreover, the constant presence of chondroid tissue, related with the mechanical induction by forces applied on the recovering area, strongly suggests that the mechanisms implied in osteointegration are related to endomembranous, rather than endochondral ossification processes