821 research outputs found

    CLONING OF THE 1.4-kb mRNA SPECIES OF HUMAN COMPLEMENT FACTOR H REVEALS A NOVEL MEMBER OF THE SHORT CONSENSUS REPEAT FAMILY RELATED TO THE CARBOXY TERMINAL OF THE CLASSICAL 150-kDa MOLECULE

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    Three factor H mRNA species of 4.3 kb, 1.8 kb, and 1.4 kb are constitutively expressed in human liver. Having previously characterized full-length cDNA clones derived from the 4.3-kb and 1.8-kb factor mRNA, we report here the isolation and eucaryotic expression of full-length cDNA clones coding for the 1.4-kbm RNA species. The 1266-bp cDNA codes for a polypeptide of 330 amino acids and contains two polyadenylation signals and a short poly(A)+tailT. he protein is composed of a leader peptide followed by five short consensus repeat domains. It shows a hybrid structure with the last three domains being almost identical to the carboxy- terminal of thcel assical 1 BO-kDa factor H molecule and the two first domains representing unique short consensus repeat structures. Eucaryotic expression in COS7 cells revealed two polypeptides derived from one cDNA clone that area lso found in human serum. Differences between the cDcNloAn es within the last three domains indicate two distinct, possibly allelic sequences that, in addition, differ from the authentic 150-kDa factor H sequence. Southern blot results support the notion that the 4.3-kb factor H and the 1.4-kb factor H-related mRNA are transcribed from two separate but highly homologous genes. Factor H, a glycoprotein of 150,00

    Detection of aphid migrations in Finland

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    Our insect immigration warning system was built on the atmospheric dispersion model that has been used in predicting long-range transport of airborne pollen. We observed immigrations with a trap network consisting of rotating tow-nets, yellow sticky traps, and suction traps. Based on our studies the aphids can be detected with radars when they occur in large numbers

    Glycodelin-A interacts with fucosyltransferase on human sperm plasma membrane to inhibit spermatozoa-zona pellucida binding

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    Fertilization depends on successful binding of the spermatozoa to the zona pellucida of the oocyte. Glycodelin-A inhibits spermatozoa-zona pellucida binding. Previous data showed that glycodelin-A receptor(s) and zona pellucida protein receptor(s) on human spermatozoa are closely related. Using a chemical cross-linking approach, the glycodelin-A-sperm receptor complex was isolated. The receptor was identified to be fucosyltransferase-5 (FUT5) by mass spectrometry and confirmed with the use of anti-FUT5 antibodies. Sperm FUT5 was an externally oriented integral membrane protein in the acrosomal region of human spermatozoa. Biologically active FUT5 was purified from spermatozoa. Co-immunoprecipitation confirmed the interaction between glycodelin-A and sperm FUT5. Solubilized zona pellucida reduced the binding of glycodelin-A to sperm FUT5. An anti-FUT5 antibody and FUT5 acceptor blocked the binding of glycodelin-A to spermatozoa and the zona binding inhibitory activity of glycodelin-A. Sperm FUT5 bound strongly to intact and solubilized human zona pellucida. The equilibrium dissociation constant of sperm FUT5 binding to solubilized zona pellucida was 42.82 pmol/ml. These observations suggest that human sperm FUT5 is a receptor of glycodelin-A and zona pellucida proteins, and that glycodelin-A inhibits spermatozoa-zona binding by blocking the binding of sperm FUT5 to the zona pellucida.published_or_final_versio

    Palmitate and oleate exert differential effects on insulin signalling and glucose uptake in human skeletal muscle cells

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    Saturated fatty acids are implicated in the development of insulin resistance, whereas unsaturated fatty acids may have a protective effect on metabolism. We tested in primary human myotubes if insulin resistance induced by saturated fatty acid palmitate can be ameliorated by concomitant exposure to unsaturated fatty acid oleate. Primary human myotubes were pretreated with palmitate, oleate or their combination for 12 h. Glucose uptake was determined by intracellular accumulation of [H-3]-2-deoxy-d-glucose, insulin signalling and activation of endoplasmic reticulum (ER) stress by Western blotting, and mitochondrial reactive oxygen species (ROS) production by fluorescent dye MitoSOX. Exposure of primary human myotubes to palmitate impaired insulin-stimulated Akt-Ser(473), AS160 and GSK-3 beta phosphorylation, induced ER stress signalling target PERK and stress kinase JNK 54 kDa isoform. These effects were virtually abolished by concomitant exposure of palmitate-treated myotubes to oleate. However, an exposure to palmitate, oleate or their combination reduced insulin-stimulated glucose uptake. This was associated with increased mitochondrial ROS production in palmitate-treated myotubes co-incubated with oleate, and was alleviated by antioxidants MitoTempo and Tempol. Thus, metabolic and intracellular signalling events diverge in myotubes treated with palmitate and oleate. Exposure of human myotubes to excess fatty acids increases ROS production and induces insulin resistance.Peer reviewe

    Zona pellucida-induced acrosome reaction in human spermatozoa is potentiated by glycodelin-A via down-regulation of extracellular signal-regulated kinases and up-regulation of zona pellucida-induced calcium influx

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    Background Glycodelin-A interacts with spermatozoa before fertilization, but its role in modulating sperm functions is not known. Zona pellucida-induced acrosome reaction is crucial to fertilization and its dysfunction is a cause of male infertility. We hypothesized that glycodelin-A, a glycoprotein found in the female reproductive tract, potentiates human spermatozoa for zona pellucida-induced acrosome reaction. Methods Glycodelin isoforms were immunoaffinity purified. The sperm intracellular cAMP concentration, protein kinase-A (PKA) and extracellular signal-regulated kinase (ERK) activities, and intracellular calcium were measured by ELISA, kinase activity assay kits and Fluo-4AM technique, respectively. The phosphorylation of inositol 1,4,5-trisphosphate type-1 receptor (IP3R1) mediated by ERK was determined by western blotting. Zona pellucida-induced acrosome reaction was detected by Pisum sativum staining. Results Pretreatment of spermatozoa with glycodelin-A significantly up-regulated adenylyl cyclase/PKA activity and down-regulated the activity of ERK and its phosphorylation of IP3R1, thereby enhancing zona pellucida-induced calcium influx and zona pellucida-induced acrosome reaction. Glycodelin-F or deglycosylated glycodelin-A did not have these actions. Treatment of spermatozoa with a protein kinase inhibitor abolished the priming activity of glycodelin-A, whilst ERK pathway inhibitors mimic the stimulatory effect of glycodelin-A on zona pellucida-induced acrosome reaction. Conclusions Glycodelin-A in the female reproductive tract sensitizes spermatozoa for zona pellucida-induced acrosome reaction in a glycosylation-specific manner through activation of the adenylyl cyclase/PKA pathway, suppression of extracellular signal-regulated kinase activation and up-regulation of zona pellucida-induced calcium influx. © 2010 The Author.postprin

    PAEP (progestagen-associated endometrial protein)

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    Review on PAEP (progestagen-associated endometrial protein), with data on DNA, on the protein encoded, and where the gene is implicated

    Anticancer activity of the protein kinase C modulator HMI-1a3 in 2D and 3D cell culture models of androgen-responsive and androgen-unresponsive prostate cancer

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    Prostate cancer is one of the most common cancers in men. Although it has a relatively high 5-year survival rate, development of resistance to standard androgen-deprivation therapy is a significant clinical problem. Therefore, novel therapeutic strategies are urgently needed. The protein kinase C (PKC) family is a putative prostate cancer drug target, but so far no PKC-targeting drugs are available for clinical use. By contrast to the standard approach of developing PKC inhibitors, we have developed isophthalate derivatives as PKC agonists. In this study, we have characterized the effects of the most potent isophthalate, 5-(hydroxymethyl) isophthalate 1a3 (HMI-1a3), on three prostate cancer cell lines (LNCaP, DU145, and PC3) using both 2D and 3D cell culture models. In 2D cell culture, HMI-1a3 reduced cell viability or proliferation in all cell lines as determined by the metabolic activity of the cells (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay) and thymidine incorporation. However, the mechanism of action in LNCaP cells was different to that in DU145 or PC3 cells. In LNCaP cells, HMI-1a3 induced a PKC-dependent activation of caspase 3/7, indicating an apoptotic response, whereas in DU145 and PC3 cells, it induced senescence, which was independent of PKC. This was observed as typical senescent morphology, increased beta-galactosidase activity, and upregulation of the senescence marker p21 and downregulation of E2F transcription factor 1. Using a multicellular spheroid model, we further showed that HMI-1a3 affects the growth of LNCaP and DU145 cells in a 3D culture, emphasizing its potential as a lead compound for cancer drug development.Peer reviewe

    Perustulon työllisyysvaikutukset : Asiantuntijahaastatteluihin ja verrannollisiin esimerkkeihin perustuva arvio

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    Perustuloon kohdistuu suuria odotuksia työllisyyden, työhön kannustamisen ja työn vastaanottamisen sekä työvoiman kysynnän ja tarjonnan suhteen. Hyötyvätkö perustulosta pienituloiset, työttömät, epävakaissa työsuhteissa työskentelevät, mikroyrittäjät vai palvelualojen työnantajat ja kolmannen sektorin toimijat? Koska perustulosta ei ole konkreettisia esimerkkejä tai empiirisiä tuloksia, ei näihin kysymyksiin ole myöskään tutkimuksiin perustuvaa vastausta. Perustulon työllisyysvaikutuksia voidaan arvioida vain epäsuorasti ja ennakoiden. Tämän selvityksen tavoitteena oli kartoittaa olemassa olevaa tutkimustietoa ja arvioida sen perusteella perustulon mahdollisia työllisyysvaikutuksia. Olemme lisäksi tehneet asiantuntijahaastatteluja ja selvittäneet, miten TE-toimistojen, kuntien ja kolmannen sektorin toimijat arvioivat perustuloa ja sen vaikutusta työvoimapolitiikan toimeenpanoon ja työllisyyspalvelujen kehittämistarpeisiin. Olemme haastatelleet myös itsensä työllistäjiä (freelance toimittajia) ja pyrkineet sitä kautta saamaan selville, miten perustulo vaikuttaisi heidän toimeentuloonsa ja työssäkäyntiin. Kirjallisuuskatsauksessa selvitimme minimitulojärjestelmistä ja minimipalkoista saatuja kokemuksia eri maista. Vaikka esimerkit eivät ole suoraan verrattavissa perustuloon, ne auttavat kuitenkin hahmottamaan monia sellaisia kysymyksiä, joita liittyy perustulon työllisyysvaikutuksiin, kuten työvoiman kysyntään ja rekrytointiin sekä työvoiman tarjontaan ja mahdollisuuteen tai haluun vastaanottaa lyhytkestoisia ja pienipalkkaisia työtehtäviä. Esimerkit auttavan ymmärtämään myös sitä, miten perustulo voi vaikuttaa makrotalouden tasolla tiettyjen toimialojen kehitykseen. Tutkimuksen toisessa osassa selvitettiin perustulon mahdollisia vaikutuksia työvoimapolitiikan toimeenpanoon. Suurin osa TE-toimistojen, kuntien ja kolmannen sektorin asiantuntijoista suhtautui myönteisesti perustuloon, vaikka kriittisiäkin näkemyksiä esitettiin erityisesti perustulon vastikkeettomuuteen liittyen. Haastateltavat olivat yksimielisiä siitä, että nykyinen sosiaali- ja työttömyysturvajärjestelmä on liian monimutkainen aiheuttaen byrokratialoukkuja, ja että työn vastaanottamisen kannustavuutta tulisi lisätä. Keinoista tai perustulon mallista, joka parhaiten poistaisi näitä esteitä, oli erilaisia näkemyksiä. Kiinnostavaa oli myös se, että perustulon käyttöönoton nähtiin edellyttävän rinnalleen ennaltaehkäisevien palvelujen kehittämistä. Ennaltaehkäiseviä palveluja tulisi olla sosiaali- ja terveyspalveluissa, vapaa-ajan palveluissa sekä työllistymistä ja sosiaalista osallisuutta tukevissa palveluissa. Nuorille työnhakijoille asiantuntijat halusivat perustuloon liitettävää seurantaa ja palvelujen aktiivista tarjoamista. Tutkimuksen kolmannessa osiossa selvitettiin perustulon mahdollisia vaikutuksia itsensä työllistäjien työhön ja toimeentuloon. Haastattelujen perusteella perustulo voisi tuoda vakautta ja turvaa itsensä työllistäjille tyypilliseen epäsäännölliseen toimeentuloon luomalla perusturvan. Perustulo voisi helpottaa etenkin niiden itsensä työllistäjien taloudellista tilannetta, joilla ei tulojen pienuuden tai elämäntilanteen vuoksi ole mahdollisuutta kasvattaa säästöpuskuria taloudellisesti huonompien kuukausien varalle. Nykyisellään sosiaaliturvajärjestelmän ei koettu tuovan turvaa tulojen vaihteluun. Vaikka selvityksen tuloksia voi pitää vain alkukartoituksena, ja sen ulkopuolelle jäi monia tärkeitä asioita, niin se kuitenkin avaa ja konkretisoi kiinnostavalla monia perustulon työllisyysvaikutuksiin liitettyjä kysymyksiä
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