537 research outputs found

    Human amniotic fluid glycoproteins expressing sialyl Lewis carbohydrate antigens stimulate progesterone production in human trophoblasts in vitro

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    Background: Progesterone is thought to mediate immune modulator effects by regulating uterine responsiveness. The aim of the study was to clarify the effect of transferrin and glycodelin A (former name PP14) as sialyl Lewis X-expressing glycoproteins on the release of progesterone by trophoblast cells in vitro. Methods: Cytotrophoblast cells were prepared from human term placentas by standard dispersion of villous tissue followed by a Percoll gradient centrifugation step. Trophoblasts were incubated with varying concentrations (50-300 mug/ml) of human amniotic fluid- and serum-transferrin as well as with glycodelin A. Culture supernatants were assayed for progesterone, human chorionic gonadotropin (hCG) and cortisol by enzyme immunometric methods. Results: The release of progesterone is increased in amniotic fluid transferrin- and glycodelin A-treated trophoblast cell cultures compared to untreated trophoblast cells. There is no relation between transferrin and the hCG or cortisol production of trophoblast cells. Conclusion: The results suggest that sialyl Lewis carbohydrate antigen-expressing amniotic fluid glycoproteins modulate the endocrine function of trophoblasts in culture by upregulating progesterone production. Copyright (C) 2004 S. Karger AG, Basel

    6.-luokkalaisten lasten kaverisuhteet koulussa sekä koulukaveruuden tärkeimmät tekijät

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    Tiivistelmä. Tutkimuksessa tarkastellaan sattumanvaraisesti valittujen 6.-luokkalaisten lasten koulukaverisuhteita. Kaverisuhteet ovat kaikille lapsille tärkeitä tuottaen ryhmään kuulumisen tunnetta. Vertaissuhteet ovat koulumaailmassa merkityksellisiä ja vaikuttavat lapsen kokonaisvaltaiseen kasvuun ja kehitykseen. Koulu on lapsuuden keskeinen ympäristö ja kaverisuhteiden luominen on yksi tärkeimmistä saavutuksista koulussa. Tutkimuksen tavoite oli selvittää 6.-luokkalaisten lasten luokan sisäisiä kaverivalintoja sekä oppilaiden perusteluita valinnoille. Aineistonkeruu tehtiin kahteen erikokoiseen kouluun. Tutkimusluokat edustivat isoa ja pientä koulua. Kyseiseen ratkaisuun päädyttiin kahden koulun tulosten vertailun saamiseksi. Menetelmäksi valittiin sosiometriikka ja aineisto kerättiin kyselylomakkeella. Sosiometriikkalla tarkoitetaan sosiaalisten suhteiden mittaamista. Sosiometrisillä menetelmillä tutkitaan ryhmän sisällä tapahtuvia sosiaalisia valintoja, kuten kaverisuhteita. Tutkimuksen aineistona toimi yhteensä 32 oppilaan kyselylomakkeiden vastaukset. Tutkimuksessa keskeisiä teemoja olivat sukupuolen sekä ulkoisten ja sisäisten tekijöiden merkitys koulukaveruudelle. Oppilaiden sosiaaliset roolit luokassa näkyivät ulkopuolisuuden ja sisäpuolisuuden erilaisiana esiintyvyyksinä. Tarkastelun kohteena olivat myös erot ja yhtäläisyydet koulujen ryhmädynamiikkassa sekä oppilaiden vastauksissa. Oppilaita pyydettiin muun muassa valitsemaan 18 vaihtoehdosta hänelle tärkeimmät tekijät kaverissa. Vaihtoehdot kyselylomakkeeseen muodostettiin Salmivallin (1998) ominaispiirteitä käsittelevän teorian pohjalta. Lisäksi teoreettisenä lähtökohtana tutkimuksessa toimivat Sheelyn ja Gutsteinin (2002) tutkimus osaamisalueista sekä Ojasen (2006) sosiaalista käyttäytymistä käsittelevä teoria. Verrattaessa ison ja pienen koulun oppilaiden valintoja, painottui pienessä koulussa enemmän kiltteyden merkitys ja isossa koulussa se, että kaverin kanssa ollaan usein samaa mieltä. Tutkimuksen molempien koulujen 6.-luokkalaisille oppilaille tärkeimmäksi tekijäksi koulukaverissa ilmeni hauskuus. Lisäksi pinnalle nousivat riitelemättömyys, avuliaisuus sekä ystävällisyys, jotka tutkimustuloksissa yhdistettiin yhteistyötaidoiksi. Tutkimustulokset ovat sidoksissa kyseisen kulttuurin, yhteiskunnan, luokan sekä sen oppilaiden yksilöllisiin kokemuksiin. Tutkimus on ajankohtainen, sillä mukaan tutkimukseen otettiin kulutusyhteiskunnan, jonka kulutustuotteet lisäävät eriarvoisuutta kouluissa, mahdollinen vaikuttavuus koulukaveruuteen

    Highly Pathogenic H5N1 Influenza A Virus Spreads Efficiently in Human Primary Monocyte-Derived Macrophages and Dendritic Cells

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    Influenza A viruses cause recurrent epidemics and occasional global pandemics. Wild birds are the natural reservoir of influenza A virus from where the virus can be transmitted to poultry or to mammals including humans. Mortality among humans in the highly pathogenic avian influenza H5N1 virus infection is even 60%. Despite intense research, there are still open questions in the pathogenicity of the H5N1 virus in humans. To characterize the H5N1 virus infection in human monocyte-derived macrophages (M phi s) and dendritic cells (DCs), we used human isolates of highly pathogenic H5N1/2004 and H5N1/1997 and low pathogenic H7N9/2013 avian influenza viruses in comparison with a seasonal H3N2/1989 virus. We noticed that the H5N1 viruses have an overwhelming ability to replicate and spread in primary human immune cell cultures, and even the addition of trypsin did not equalize the infectivity of H7N9 or H3N2 viruses to the level seen with H5N1 virus. H5N1 virus stocks contained more often propagation-competent viruses than the H7N9 or H3N2 viruses. The data also showed that human DCs and M phi s maintain 1,000- and 10,000-fold increase in the production of infectious H5N1 virus, respectively. Both analyzed highly pathogenic H5N1 viruses showed multi-cycle infection in primary human DCs and M phi s, whereas the H3N2 and H7N9 viruses were incapable of spreading in immune cells. Interestingly, H5N1 virus was able to spread extremely efficiently despite the strong induction of antiviral interferon gene expression, which may in part explain the high pathogenicity of H5N1 virus infection in humans

    The role of individual and social variables in task performance.

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    This paper reports on a data-based study in which we explored - as part of a larger-scale British-Hungarian research project - the effects of a number of affective and social variables on foreign language (L2) learners’ engagement in oral argumentative tasks. The assumption underlying the investigation was that students’ verbal behaviour in oral task situations is partly determined by a number of non-linguistic and non-cognitive factors whose examination may constitute a potentially fruitful extension of existing task-based research paradigms. The independent variables in the study included various aspects of L2 motivation and several factors characterizing the learner groups the participating students were members of (such as group cohesiveness and intermember relations), as well as the learners’ L2 proficiency and ‘willingness to communicate’ in their L1. The dependent variables involved objective measures of the students’ language output in two oral argumentative tasks (one in the learners’ L1, the other in their L2): the quantity of speech and the number of turns produced by the speakers. The results provide insights into the interrelationship of the multiple variables determining the learners’ task engagement, and suggest a multi-level construct whereby some independent variables only come into force when certain conditions have been met

    Pandemic influenza A(H1N1 pdm09) vaccine induced high levels of influenza-specific IgG and IgM antibodies as analyzed by enzyme immunoassay and dual-mode multiplex microarray immunoassay methods

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    Influenza A viruses continue to circulate throughout the world as yearly epidemics or occasional pandemics. Influenza infections can be prevented by seasonal multivalent or monovalent pandemic vaccines. In the present study, we describe a novel multiplex microarray immunoassay (MAIA) for simultaneous measurement of virus-specific IgG and IgM antibodies using Pandemrix-vaccinated adult sera collected at day 0 and 28 and 180 days after vaccination as the study material. MAIA showed excellent correlation with a conventional enzyme immunoassay (EIA) in both IgG and IgM anti-influenza A antibodies and good correlation with hemagglutination inhibition (HI) test. Pandemrix vaccine induced 5-30 fold increases in anti-H1N1pdm09 influenza antibodies as measured by HI, EIA or MAIA. A clear increase in virus-specific IgG antibodies was found in 93-97% of vaccinees by MAIA and EIA. Virus-specific IgM antibodies were found in 90-92% of vaccinees by MAIA and EIA, respectively and IgM antibodies persisted for up to 6 months after vaccination in 55-62% of the vaccinees. Pandemic influenza vaccine induced strong anti-influenza A IgG and IgM responses that persisted several months after vaccination. MAIA was demonstrated to be an excellent method for simultaneous measurement of antiviral IgG and IgM antibodies against multiple virus antigens. Thus the method is well suitable for large scale epidemiological and vaccine immunity studies. (C) 2020 Elsevier Ltd. All rights reserved

    Serological Array-in-Well Multiplex Assay Reveals a High Rate of Respiratory Virus Infections and Reinfections in Young Children

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    Serological assays are used to diagnose and characterize host immune responses against microbial pathogens. Microarray technologies facilitate high-throughput immunoassays of antibody detection against multiple pathogens simultaneously. To improve survey of influenza A virus (IAV), influenza B virus (IBV), respiratory syncytial virus (RSV), and adenovirus (AdV) antibody levels, we developed a microarray consisting of IAV H1N1, IAV H1N1pdm09 (vaccine), IAV H3N2, IBV Victoria, IBV Yamagata, RSV, AdV type 5 hexon protein, and control antigens printed on the bottom of a microtiter plate well. Bound IgG antibodies were detected with anti-human IgG-coated photon-upconverting nanoparticles and measured with a photoluminescence imager. The performance of the microarray immunoassay (MAIA) was evaluated with serum samples (n = 576) collected from children (n - 288) at 1 and 2 years of age and tested by standard enzyme immunoassays (EIAs) for antibodies to IAV vaccine and RSV. EIAs and MAIA showed substantial to almost perfect agreement (Cohen's kappa, 0.62 to 0.83). Applying MAIA, we found seroprevalences of 55% for IAV H1N1, 54% for IAV vaccine, 30% for IAV H3N2, 24% for IBV Victoria, 25% for IBV Yamagata, 38% for RSV, and 26% for AdV in 1-year-old children (n = 768). By the age of 2 years, IgG seropositivity rates (n = 714) increased to 74% for IAV H1N1, 71% for IAV vaccine, 49% for IAV H3N2, 47% for IBV Yamagata, 49% for IBV Victoria, 68% for RSV, and 58% for AdV. By analyzing increases in antibody levels not biased by vaccinations, we found a reinfection rate of 40% for RSV and 31% for AdV in children between 1 and 2 years of age.IMPORTANCE The multiplex immunoassay was successfully used to simultaneously detect antibodies against seven different viruses. The developed serological microarray is a new promising tool for diagnostic, epidemiological, and seroprevalence analyses of virus infections

    Zika Virus Non-Structural Protein NS5 Inhibits the RIG-I Pathway and Interferon Lambda 1 Promoter Activation by Targeting IKK Epsilon

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    The Zika virus (ZIKV) is a member of the Flaviviridae family and an important human pathogen. Most pathogenic viruses encode proteins that interfere with the activation of host innate immune responses. Like other flaviviruses, ZIKV interferes with the expression of interferon (IFN) genes and inhibits IFN-induced antiviral responses. ZIKV infects through epithelial barriers where IFN-lambda 1 is an important antiviral molecule. In this study, we analyzed the effects of ZIKV proteins on the activation of IFN-lambda 1 promoter. All ZIKV proteins were cloned and transiently expressed. ZIKV NS5, but no other ZIKV protein, was able to interfere with the RIG-I signaling pathway. This inhibition took place upstream of interferon regulatory factor 3 (IRF3) resulting in reduced phosphorylation of IRF3 and reduced activation of IFN-lambda 1 promoter. Furthermore, we showed that ZIKV NS5 interacts with the protein kinase IKK epsilon, which is likely critical to the observed inhibition of phosphorylation of IRF3
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