39 research outputs found

    Condensation of the plasma membrane at the site of T lymphocyte activation

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    After activation, T lymphocytes restructure their cell surface to form membrane domains at T cell receptor (TCR)–signaling foci and immunological synapses (ISs). To address whether these rearrangements involve alteration in the structure of the plasma membrane bilayer, we used the fluorescent probe Laurdan to visualize its lipid order. We observed a condensation of the plasma membrane at TCR activation sites. The formation of ordered domains depends on the presence of the transmembrane protein linker for the activation of T cells and Src kinase activity. Moreover, these ordered domains are stabilized by the actin cytoskeleton. Membrane condensation occurs upon TCR stimulation alone but is prolonged by CD28 costimulation with TCR. In ISs, which are formed by conjugates of TCR transgenic T lymphocytes and cognate antigen-presenting cells, similar condensed membrane phases form first in central regions and later at the periphery of synapses. The formation of condensed membrane domains at T cell activation sites biophysically reflects membrane raft accumulation, which has potential implications for signaling at ISs

    Sobre la presència de Teucrium pumilum i Teucrium libanitis (Lamiaceae) a la província de València.

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    12p. fotog.color.[EN] About the presence of Teucrium pumilum and Teucrium libanitis (Lamiaceae) in the Valencian province, Spain.- Teucrium pumilum and T. libanitis have been cited from Valencia province (Spain) since the middle of the XXth Century from the gypsic soils in the Valle de Ayora-Cofrentes shire. The analysis of specimens and labels is not conclusive; no specimen would certify the presence of any of these taxa. The field identification and their inclusion in a phyotosociological table (relevé) by Rivas Goday are the only basis of their presence in the territory in a particular moment of the recent Spanish botanical history. Additionally, the unique herbarium specimen from Valencia, impossible to assign a concrete geographic locality, which was traditionally assigned to T. pumilum by some authors, is actually its congeneric T. carolipaui.[ES] Sobre la presencia de Teucrium pumilum y Teucrium libanitis (Lamiaceae) en la provincia de Valencia.- Teucrium pumilum y T. libanitis son dos especies que han sido citadas como presentes en la provincia de Valencia desde mediados del siglo XX, para los yesos que afloran en la comarca del Valle de Ayora-Cofrentes. El análisis de las etiquetas de los pliegos de los herbarios no es concluyente; ningún pliego testigo certificaría la presencia de estas especies. La determinación de visu por parte de Rivas Goday, y su inclusión en una tabla de inventarios fitosociológica, son el único fundamento de su existencia en la zona en algún momento determinado de la reciente historia botánica española. Además, para T. pumilum, el pliego de herbario que tradicionalmente se ha asignado a la cita valenciana se trata de una confusión en la determinación por parte de algunos autores con su congénere T. carolipaui, siendo imposible al mismo tiempo asignar una localidad geográfica concreta a este material.[CAT] Sobre la presència de Teucrium pumilum i Teucrium libanitis (Lamiaceae) a la província de València.- Teucrium pumilum i T. libanitis són dues espècies que han estat citades com a presents a la província de València des de mitjans del segle XX, sobre els guixos que afloren a la comarca de la Vall d’Aiora-Cofrents. L’anàlisi de les etiquetes dels plecs dels herbaris no és concloent; cap plec testimoni certificaria la presència d’aquestes espècies. La determinació de visu per part de Rivas Goday, i la seva inclusió en una taula d’inventaris fitosociològica, són l’únic fonament de la seva existència a la zona en un moment determinat de la recent història botànica espanyola. A més, per a T. pumilum, el plec d’herbari que tradicionalment s’ ha assignat a la cita valenciana es tracta d’una confusió en la determinació per part d’alguns autors amb el seu congènere.Peer reviewe

    Integrating biological vasculature into a multi-organ-chip microsystem

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    Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.A chip-based system mimicking the transport function of the human cardiovascular system has been established at minute but standardized microsystem scale. A peristaltic on-chip micropump generates pulsatile shear stress in a widely adjustable physiological range within a microchannel circuit entirely covered on all fluid contact surfaces with human dermal microvascular endothelial cells. This microvascular transport system can be reproducibly established within four days, independently of the individual endothelial cell donor background. It interconnects two standard tissue culture compartments, each of 5 mm diameter, through microfluidic channels of 500 μm width. Further vessel branching and vessel diameter reduction down to a microvessel scale of approximately 40 μm width was realised by a two-photon laser ablation technique applied to inserts, designed for the convenient establishment of individual organ equivalents in the tissue culture compartments at a later time. The chip layout ensures physiological fluid-to-tissue ratios. Moreover, an in-depth microscopic analysis revealed the fine-tuned adjustment of endothelial cell behaviour to local shear stresses along the microvasculature of the system. Time-lapse and 3D imaging two-photon microscopy were used to visualise details of spatiotemporal adherence of the endothelial cells to the channel system and to each other. The first indicative long-term experiments revealed stable performance over two and four weeks. The potential application of this system for the future establishment of human-on-a-chip systems and basic human endothelial cell research is discussed.BMBF, 0315569, GO-Bio 3: Multi-Organ-Bioreaktoren für die prädiktive Substanztestung im Chipforma

    Right-Sided Location Not Associated With Missed Colorectal Adenomas in an Individual-Level Reanalysis of Tandem Colonoscopy Studies

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    Background & Aims Interval cancers occur more frequently in the right colon. One reason could be that right-sided adenomas are frequently missed in colonoscopy examinations. We reanalyzed data from tandem colonoscopies to assess adenoma miss rates in relation to location and other factors. Methods We pooled data from 8 randomized tandem trials comprising 2218 patients who had diagnostic or screening colonoscopies (adenomas detected in 49.8% of patients). We performed a mixed-effects logistic regression with patients as cluster effects with different independent parameters. Factors analyzed included location (left vs right, splenic flexure as cutoff), adenoma size, form, and histologic features. Analyses were controlled for potential confounding factors such as patient sex and age, colonoscopy indication, and bowel cleanliness. Results Right-side location was not an independent risk factor for missed adenomas (odds ratio [OR] compared with the left side, 0.94; 95% CI, 0.75–1.17). However, compared with adenomas ≤5 mm, the OR for missing adenomas of 6–9 mm was 0.62 (95% CI, 0.44–0.87), and the OR for missing adenomas of ≥10 mm was 0.51 (95% CI, 0.33–0.77). Compared with pedunculated adenomas, sessile (OR, 1.82; 95% CI, 1.16–2.85) and flat adenomas (OR, 2.47; 95% CI, 1.49–4.10) were more likely to be missed. Histologic features were not significant risk factors for missed adenomas (OR for adenomas with high-grade intraepithelial neoplasia, 0.68; 95% CI, 0.34–1.37 and OR for sessile serrated adenomas, 0.87; 95% CI, 0.47–1.64 compared with low-grade adenomas). Men had a higher number of adenomas per colonoscopy (1.27; 95% CI, 1.21–1.33) than women (0.86; 95% CI, 0.80–0.93). Men were less likely to have missed adenomas than women (OR for missed adenomas in men, 0.73; 95% CI, 0.57–0.94). Conclusions In an analysis of data from 8 randomized trials, we found that right-side location of an adenoma does not increase its odds for being missed during colonoscopy but that adenoma size and histologic features do increase risk. Further studies are needed to determine why adenomas are more frequently missed during colonoscopies in women than men

    Operationalization of a multidimensional sex/gender concept for quantitative environmental health research and implementation in the KORA study: Results of the collaborative research project INGER

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    BackgroundIn environmental health research, sex and gender are not yet adequately considered. There is a need to improve data collection in population-based environmental health studies by comprehensively surveying sex/gender-related aspects according to gender theoretical concepts. Thus, within the joint project INGER we developed a multidimensional sex/gender concept which we aimed to operationalize and to test the operationalization for feasibility.MethodsIn an iterative process, we created questionnaire modules which quantitatively captured the requirements of the INGER sex/gender concept. We deployed it in the KORA cohort (Cooperative Health Research in the Region of Augsburg, Germany) in 2019 and evaluated response and missing rates.ResultsThe individual sex/gender self-concept was surveyed via a two-step approach that asked for sex assigned at birth and the current sex/gender identity. Additionally, we used existing tools to query internalized sex/gender roles and externalized sex/gender expressions. Adapted to the KORA population, we asked for discrimination experiences and care and household activities contributing to explain structural sex/gender relations. Further intersectionality-related social categories (e.g., socio-economic position), lifestyle and psychosocial factors were covered through data available in KORA. We could not identify appropriate tools to assess the true biological sex, sexual orientation and ethnic/cultural identity, which have yet to be developed or improved. The response-rate was 71%, the evaluation of 3,743 questionnaires showed a low missing rate. Prevalence of marginalized groups regarding sex/gender identity and definable by experiences of discrimination was very low.ConclusionWe have shown how the multidimensional INGER sex/gender concept can be operationalized according to an European and North American understanding of sex/gender for use in quantitative research. The questionnaire modules proved feasible in an epidemiologic cohort study. Being a balancing act between theoretical concepts and its quantitative implementation our operationalization paves the way for an adequate consideration of sex/gender in environmental health research

    The genome, transcriptome, and proteome of the fish parasite Pomphorhynchus laevis (Acanthocephala).

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    Thorny-headed worms (Acanthocephala) are endoparasites exploiting Mandibulata (Arthropoda) and Gnathostomata (Vertebrata). Despite their world-wide occurrence and economic relevance as a pest, genome and transcriptome assemblies have not been published before. However, such data might hold clues for a sustainable control of acanthocephalans in animal production. For this reason, we present the first draft of an acanthocephalan nuclear genome, besides the mitochondrial one, using the fish parasite Pomphorhynchus laevis (Palaeacanthocephala) as a model. Additionally, we have assembled and annotated the transcriptome of this species and the proteins encoded. A hybrid assembly of long and short reads resulted in a near-complete P. laevis draft genome of ca. 260 Mb, comprising a large repetitive portion of ca. 63%. Numbers of transcripts and translated proteins (35,683) were within the range of other members of the Rotifera-Acanthocephala clade. Our data additionally demonstrate a significant reorganization of the acanthocephalan gene repertoire. Thus, more than 20% of the usually conserved metazoan genes were lacking in P. laevis. Ontology analysis of the retained genes revealed many connections to the incorporation of carotinoids. These are probably taken up via the surface together with lipids, thus accounting for the orange coloration of P. laevis. Furthermore, we found transcripts and protein sequences to be more derived in P. laevis than in rotifers from Monogononta and Bdelloidea. This was especially the case in genes involved in energy metabolism, which might reflect the acanthocephalan ability to use the scarce oxygen in the host intestine for respiration and simultaneously carry out fermentation. Increased plasticity of the gene repertoire through the integration of foreign DNA into the nuclear genome seems to be another underpinning factor of the evolutionary success of acanthocephalans. In any case, energy-related genes and their proteins may be considered as candidate targets for the acanthocephalan control
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