MHC/Peptide-Specific Interaction of the Humoral Immune System: A New Category of Antibodies.

Abs bind to unprocessed Ags, whereas cytotoxic CD8(+) T cells recognize peptides derived from endogenously processed Ags presented in the context of class I MHC complexes. We screened, by ELISA, human sera for Abs reacting specifically with the influenza matrix protein (IMP)-derived peptide58-66 displayed by HLA-A*0201 complexes. Among 653 healthy volunteers, blood donors, and women on delivery, high-titered HLA-A*0201/IMP58-66 complex-specific IgG Abs were detected in 11 females with a history of pregnancies and in 1 male, all HLA-A*0201(-). These Abs had the same specificity as HLA-A*0201/IMP58-66-specific cytotoxic T cells and bound neither to HLA-A*0201 nor the peptide alone. No such Abs were detected in HLA-A*0201(+) volunteers. These Abs were not cross-reactive to other self-MHC class I alleles displaying IMP58-66, but bound to MHC class I complexes of an HLA nonidentical offspring. HLA-A*0201/IMP58-66 Abs were also detected in the cord blood of newborns, indicating that HLA-A*0201/IMP58-66 Abs are produced in HLA-A*0201(-) mothers and enter the fetal blood system. That Abs can bind to peptides derived from endogenous Ags presented by MHC complexes opens new perspectives on interactions between the cellular and humoral immune system.

Asymmetrical nature of the Trollius-Chiastocheta interaction: insights into the evolution of nursery pollination systems

The mutualistic versus antagonistic nature of an interaction is defined by costs and benefits of each partner, which may vary depending on the environment. Contrasting with this dynamic view, several pollination interactions are considered as strictly obligate and mutualistic. Here, we focus on the interaction between Trollius europaeus and Chiastocheta flies, considered as a specialized and obligate nursery pollination system - the flies are thought to be exclusive pollinators of the plant and their larvae develop only in T.europaeus fruits. In this system, features such as the globelike flower shape are claimed to have evolved in a coevolutionary context. We examine the specificity of this pollination system and measure traits related to offspring fitness in isolated T.europaeus populations, in some of which Chiastocheta flies have gone extinct. We hypothesize that if this interaction is specific and obligate, the plant should experience dramatic drop in its relative fitness in the absence of Chiastocheta. Contrasting with this hypothesis, T.europaeus populations without flies demonstrate a similar relative fitness to those with the flies present, contradicting the putative obligatory nature of this pollination system. It also agrees with our observation that many other insects also visit and carry pollen among T.europaeus flowers. We propose that the interaction could have evolved through maximization of by-product benefits of the Chiastocheta visits, through the male flower function, and selection on floral traits by the most effective pollinator. We argue this mechanism is also central in the evolution of other nursery pollination systems.

Systematic evaluation of matrix effects in hydrophilic interaction chromatography versus reversed phase liquid chromatography coupled to mass spectrometry.

Reversed phase liquid chromatography (RPLC) coupled to mass spectrometry (MS) is the gold standard technique in bioanalysis. However, hydrophilic interaction chromatography (HILIC) could represent a viable alternative to RPLC for the analysis of polar and/or ionizable compounds, as it often provides higher MS sensitivity and alternative selectivity. Nevertheless, this technique can be also prone to matrix effects (ME). ME are one of the major issues in quantitative LC-MS bioanalysis. To ensure acceptable method performance (i.e., trueness and precision), a careful evaluation and minimization of ME is required. In the present study, the incidence of ME in HILIC-MS/MS and RPLC-MS/MS was compared for plasma and urine samples using two representative sets of 38 pharmaceutical compounds and 40 doping agents, respectively. The optimal generic chromatographic conditions in terms of selectivity with respect to interfering compounds were established in both chromatographic modes by testing three different stationary phases in each mode with different mobile phase pH. A second step involved the assessment of ME in RPLC and HILIC under the best generic conditions, using the post-extraction addition method. Biological samples were prepared using two different sample pre-treatments, i.e., a non-selective sample clean-up procedure (protein precipitation and simple dilution for plasma and urine samples, respectively) and a selective sample preparation, i.e., solid phase extraction for both matrices. The non-selective pretreatments led to significantly less ME in RPLC vs. HILIC conditions regardless of the matrix. On the contrary, HILIC appeared as a valuable alternative to RPLC for plasma and urine samples treated by a selective sample preparation. Indeed, in the case of selective sample preparation, the compounds influenced by ME were different in HILIC and RPLC, and lower and similar ME occurrence was generally observed in RPLC vs. HILIC for urine and plasma samples, respectively. The complementary of both chromatographic modes was also demonstrated, as ME was observed only scarcely for urine and plasma samples when selecting the most appropriate chromatographic mode.

Adaptation and validation of the Spanish Version of the 'Survey Work-Home Interaction-NijmeGen' (SWING) to Spanish speaking countries

The purpose of this study is the adaptation and validation of the"Survey Work-Home Interaction NijmeGen" (SWING) developed by Geurts and colleagues to Spanish speaking countries (SWING-SSC). In order to analyze the questionnaire"s psychometric properties, confirmatory factor analysis (CFA) was carried out with a sample of 203 employees from various Spanish-speaking countries. Criterion related validity was tested by examining correlations between the SWING-SSC, and the theoretically relevant variables: health, role conflict, role clarity and supervisor support. Finally, reliability was tested analyzing the internal consistency of the scales. The analyses carried out indicate that SWING-SSC has good psychometric properties. In addition, the present results support the relation of the construct with health, role conflict, role clarity, and supervisor support. This study offers evidence for a sound work-life balance measure that contributes to the encouragement adequate conditions in the workplace, to reduce the conflict between the two spheres of professional and personal life, and to enhance positive relationships.

Activation of p53 by nutlin-3a induces apoptosis and cellular senescence in human glioblastoma multiforme

Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor in adults. Despite concerted efforts to improve current therapies and develop novel clinical approaches, patient survival remains poor. As such, increasing attention has focused on developing new therapeutic strategies that specifically target the apoptotic pathway in order to improve treatment responses. Recently, nutlins, small-molecule antagonists of MDM2, have been developed to inhibit p53-MDM2 interaction and activate p53 signaling in cancer cells. Glioma cell lines and primary cultured glioblastoma cells were treated with nutlin-3a. Nutlin-3a induced p53-dependent G1- and G2-M cell cycle arrest and apoptosis in glioma cell lines with normal TP53 status. In addition, nutlin-arrested glioma cells show morphological features of senescence and persistent induction of p21 protein. Furthermore, senescence induced by nutlin-3a might be depending on mTOR pathway activity. In wild-type TP53 primary cultured cells, exposure to nutlin-3a resulted in variable degrees of apoptosis as well as cellular features of senescence. Nutlin-3a-induced apoptosis and senescence were firmly dependent on the presence of functional p53, as revealed by the fact that glioblastoma cells with knockdown p53 with specific siRNA, or cells with mutated or functionally impaired p53 pathway, were completely insensitive to the drug. Finally, we also found that nutlin-3a increased response of glioma cells to radiation therapy. The results provide a basis for the rational use of MDM2 antagonists as a novel treatment option for glioblastoma patients.

Mode of interaction of the Gαo subunit of heterotrimeric G proteins with the GoLoco1 motif of Drosophila Pins is determined by guanine nucleotides.

Drosophila GoLoco motif-containing protein Pins is unusual in its highly efficient interaction with both GDP- and the GTP-loaded forms of the α-subunit of the heterotrimeric Go protein. We analysed the interactions of Gαo in its two nucleotide forms with GoLoco1-the first of the three GoLoco domains of Pins-and the possible structures of the resulting complexes, through combination of conventional fluorescence and FRET measurements as well as through molecular modelling. Our data suggest that the orientation of the GoLoco1 motif on Gαo significantly differs between the two nucleotide states of the latter. In other words, a rotation of the GoLoco1 peptide in respect with Gαo must accompany the nucleotide exchange in Gαo. The sterical hindrance requiring such a rotation probably contributes to the guanine nucleotide exchange inhibitor activity of GoLoco1 and Pins as a whole. Our data have important implications for the mechanisms of Pins regulation in the process of asymmetric cell divisions.

Activation of p53 by nutlin-3a induces apoptosis and cellular senescence in human glioblastoma multiforme

Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor in adults. Despite concerted efforts to improve current therapies and develop novel clinical approaches, patient survival remains poor. As such, increasing attention has focused on developing new therapeutic strategies that specifically target the apoptotic pathway in order to improve treatment responses. Recently, nutlins, small-molecule antagonists of MDM2, have been developed to inhibit p53-MDM2 interaction and activate p53 signaling in cancer cells. Glioma cell lines and primary cultured glioblastoma cells were treated with nutlin-3a. Nutlin-3a induced p53-dependent G1- and G2-M cell cycle arrest and apoptosis in glioma cell lines with normal TP53 status. In addition, nutlin-arrested glioma cells show morphological features of senescence and persistent induction of p21 protein. Furthermore, senescence induced by nutlin-3a might be depending on mTOR pathway activity. In wild-type TP53 primary cultured cells, exposure to nutlin-3a resulted in variable degrees of apoptosis as well as cellular features of senescence. Nutlin-3a-induced apoptosis and senescence were firmly dependent on the presence of functional p53, as revealed by the fact that glioblastoma cells with knockdown p53 with specific siRNA, or cells with mutated or functionally impaired p53 pathway, were completely insensitive to the drug. Finally, we also found that nutlin-3a increased response of glioma cells to radiation therapy. The results provide a basis for the rational use of MDM2 antagonists as a novel treatment option for glioblastoma patients.

Playing cat and mouse : consumer empowerment and marketing interaction on the net

Peer-reviewed

Analyzing and supporting interaction in complex scenarios: the case of DS106

DS106 promotes learners to build a digital identity + personal infrastructure, but how can be the global course infrastructure be improved?

Äitiys kulttuurisina odotuksina

Tutkimuksen kohteena ovat äitiydelle tuotetut kulttuuriset odotukset, joita tarkastellaan kahdella yhteiskunnallisella keskustelufoorumilla. Tutkimuksessa tarkastellaan yhtäältä lastensuojelun perhetyössä toimivien ammattilaisten ja toisaalta median puhetta äitiydestä. Tutkimuksen tavoitteena on tehdä näkyväksi vaihtoehtoisia tapoja konstruoida äitiyttä hyvänä tai riittämättömänä sekä haastaa pohtimaan erilaisten tulkintojen perusteita ja seurauksia lastensuojelutyössä. Kulttuuriset, äitiyttä koskevat odotukset vaikuttavat myös siihen, miten äitiys henkilökohtaisella tasolla koetaan. Äitiyden kulttuurista määrittelyä analysoidaan kahdesta tekstiaineistosta. Yhtenä aineistona ovat Stakesissa vuonna 1999 toteutetun Perhetyöprojektin yhteydessä kerätyt, lastensuojelussa toimivien perhetyöammattilaisten ryhmäkeskustelut. Toisena aineistona on projektin ajankohtana ilmestyneistä suomalaisista naisten- ja perhelehdistä (Kotiliesi, Anna, Kaksplus) kerätyt äitien haastattelut. Tutkimuksessa kysytään 1) Mihin ammattilaisten äitejä koskeva huolipuhe kiinnittyy ja millaisia kulttuurisia äitiyden odotuksia se konstruoi? 2) Millaisia äitiyden odotuksia median äitihaastattelut konstruoivat? 3) Millaisen äitiyden odotushorisontin nämä puhekäytännöt yhdessä tuottavat? Analyysin teoreettis-metodologisina kulmakivinä ovat sosiaalinen konstruktionismi ja feministinen tietokäsitys. Analyysimenetelmänä on laadullinen, aineistojen ehdoilla etenevä, feministisesti ja kriittisesti sävyttynyt lukutapa, joka hyödyntää teemoittelun, diskurssianalyysin ja feministisen metodologian ideoita ja käsitteitä. Analysoitavana olevissa keskusteluissa äitiyttä konstruoidaan lapsen tarpeiden (ammattilaiset) ja naisen tarpeiden (media) näkökulmista. Ammattilaiset puhuvat tilanteista, joissa äitien toiminta rikkoo kulttuurista hyvän äidin kuvaa, vaarantaa lapsen hyvinvointia ja äitiyteen joudutaan puuttumaan ammatillisesti. Ammattilaisten tulkinnat kuvaavat taitavaa lapsen edun näkökulmasta tehtyä arviointia, jonka kiintopisteenä ovat äidit yksilöllisine ominaisuuksineen ja piirteineen. Ammatillisen huolipuheen keskiössä ovat äidin vuorovaikutussuhteet sekä äidin tunteet, käyttäytyminen ja asenteet. Riittävää äitiyttä konstruoi kodin luominen, kiintymyssuhteen rakentaminen ja lapsen ensisijaiseksi asettaminen. Sen sijaan vaikuttaa siltä, ettei äitiyden arviointia juurikaan tehdä suhteessa äidin muihin identiteetteihin tai äitiyden toteuttamisen kontekstiin. Paikoin ammattilaisten tulkinnat heijastavat myös stereotyyppisiä ja idealistisia odotuksia, joita vasten äitiyttä arvioidaan. Tällaiset piirteet voivat kertoa siitä, että äitien avuntarpeet jäävät lastensuojelutyössä kohtaamatta ja ymmärtämättä. Mediapuhe äitiydestä käydään naiseuden ja äitiyden mallien antamisen kontekstissa. Puheen keskiössä ovat mediajulkisuuteen päässeiden naisten äidiksi tuloon ja äitiyden toteuttamiseen liittyvät valinnat ja käyttäytyminen. Mediapuhe on puhetta kulttuuristen ja ammatillisten äitiyden odotusten rikkomisesta, uudelleen tulkinnasta ja niiden muovaamisesta itselle sopiviksi. Mediapuheessa hyvää äitiyttä konstruoi äidin itsenäisyys ja oma aika, sosiaalisen elämän rikkaus, ammatillinen identiteetti ja persoonalliset valinnat. Aineistojen kautta rakentuu moninaisten ja ristiriitaisten, äitejä eri suuntaan vetävien kulttuuristen odotusten kirjo. Odotukset jäsentyvät neljälle ulottuvuudelle: 1) lapselle omistautuva – itseään toteuttava, 2) emotionaalinen side – rationaalinen tehtävä, 3) odotuksia toteuttava – omaehtoinen, 4) itsenäinen - äitiyttä jakava. Äitiyden toteuttaminen kulttuurisesti ”oikein” on näiden odotusten välissä tasapainoilua. Ulottuvuuksien kautta esille tulevat kaksoisviestit voivat heikentää äitien itsetuntoa, tuottaa riittämättömyyden tunteita tai yllyttää suorittamaan äitiyttä. Myös äitiyden ammatillinen tukeminen edellyttää tasapainoilua, jottei äitejä idealisoida tai syyllistetä kulttuurisia odotuksia vasten.

One pot obtention of a tetrabutylammonium hydroxide solution for ironporphyrin-OH- interaction studies in organic solvents

In this work we report the obtention of a tetrabutylammonium hydroxide (TBAOH) solution in acetonitrile in a one pot process in order to study the interaction ironporphyrinOH- in non-aqueous systems. All the reactions were carried out under dry argon atmosphere to prevent the contamination of the solution with CO2, which leads to the formation of (TBA)2CO3.