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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
331

Method development for enrichment of autoantibodies from human plasma

Skoglund, Lovisa January 2020 (has links)
Antibodies are naturally occurring in humans, with the function to protect the body from pathogens. Occasionally, antibodies towards the body’s own proteins are produced. These so called autoantibodies are present in healthy individuals but are also highly associated with diseases with autoimmune involvement. Research on autoantibodies in healthy individuals as well as in patients is important to gain knowledge and facilitate prognostics, diagnostics and treatment. However, a method for purification of these antibodies has not previously been described. In the present project, an enrichment procedure of circulating autoantibodies found in human plasma is described. Twenty protein fragments previously known to be highly reactive were attached to magnetic microbeads, enabling autoantibodies from eight human plasma sample pools to be captured. The six antigens with highest shown reactivity were chosen for elution procedure. Using pH alterations and heat treatments, a successful elution and enrichment procedure was developed. With analysis of the eluted autoantibodies, it can be established that the enrichment was successful on multiple sample pools. In the scaled-up procedure, autoantibodies could be enriched in all positive antigen-sample combinations. Concentration measurements indicated amounts of up to 0.23 mg antibodies per ml eluate. This implies sufficient concentrations for further applications of the enriched autoantibodies. / Antikroppar förekommer naturligt i människor, med syftet att skydda kroppen från patogen. I vissa fall skapas av misstag antikroppar som angriper kroppens egna proteiner. Dessa autoantikroppar förekommer hos alla människor, såväl friska som sjuka, men de är också starkt förknippade med autoimmuna sjukdomar. Kunskapen om autoantikroppar hos friska personer och hos patienter är idag begränsad, men fortsatt forskning inom området förväntas i framtiden underlätta prognostik, diagnostik och behandling. Hittills har ingen metod för anrikning av autoantikroppar ur blodplasma beskrivits. I detta projekt beskrivs en anrikningsmetod för autoantikroppar ur blodplasma från människa. Tjugo tidigare kända högreaktiva proteinfragment fästes på magnetiska mikrokulor. Dessa antigen-täckta mikrokulor användes för att fånga in autoantikroppar från åtta plasmaprover. De sex proteinfragment som hade högst reaktivitet i dessa prover valdes ut för elueringsförsök. Eluering genomfördes under basiska följt av sura förhållanden, tillsammans med värmebehandling. Denna elueringsmetod fungerade för anrikning av några autoantikroppar från flera av plasmaproverna. I ett utökat experiment kunde autoantikroppar anrikas ur alla kombinationer av antigen och plasmaprov som förväntades ge signal. Koncentrationen av autoantikroppar i eluaten uppskattades till högst 0.23 mg/ml. Denna koncentration är tillräcklig för flera vanliga metoder där antikroppar används.
332

Implication of protein redox modifications in the regulation of cellular antiviral signaling pathways

Zamorano, Natalia 11 1900 (has links)
Le développement d'une réponse antivirale contre les virus, incluant le virus de l'immunodéficience humaine (VIH), le virus de la grippe, le virus respiratoire syncytial (VRS) ou le SARS-CoV-2, repose sur l'activation d'adaptateurs intracellulaires qui conduisent à la production d'interférons et de cytokines proinflammatoires. Une activation correctement équilibrée de ces voies permet à la cellule de monter un état antiviral, essentiel pour restreindre la réplication et la propagation du virus. Les acides nucléiques viraux à base d'ADN, présents à l’intérieur de la cellule, peuvent être reconnus par la GMP-AMP Synthase cyclique (cGAS), qui transduit ensuite le signal via l'adaptateur Stimulateur des gènes d'interféron (STING). D'autre part, les acides nucléiques viraux à ARN sont reconnus par les récepteurs de type RIG-I (RLR), qui interagissent ensuite avec l'adaptateur de signalisation antivirale mitochondrial (MAVS). STING et MAVS sont des protéines pivots de signalisation localisées dans des compartiments membranaires, régulées par plusieurs modifications post-traductionnelles (PTM) et, lors de l'activation, elles subissent des événements de polymérisation allant jusqu'à la formation d'agrégats fonctionnels. Des données soutiennent un rôle des espèces réactives de l'oxygène (ROS) dans la régulation des voies dépendantes de STING et MAVS, mais les mécanismes restent mal définis. Les ROS sont connus pour modifier la structure et l'activité des protéines de signalisation via des PTMs oxydatives réversibles sur des cystéines (Cys ox-PTM). Les Cys ox-PTM réversibles consistent en une variété de modifications, les plus étudiées étant la S-sulfénylation (Cys-SOH), la S-glutathionylation (Cys-SSG) et le disulfure (S-S). Afin d’identifier les Cys ox-PTM qui affectent les protéines de signalisation impliquées dans la réponse antivirale, nous avons effectué une identification à l'échelle du protéome des Cys ox-PTM induites par les ROS en utilisant un marquage bioswitch à base de maléimide couplé à la spectrométrie de masse. Nous avons identifié 2720 sites Cys ox-PTM uniques englobant 1473 protéines avec une abondance, localisation et fonctions distinctes. Parmi ceux-ci, nous avons découvert l'oxydation de STING sur la Cys148 et Cys206. Cette dernière étant inductible par le stress oxydatif ou par le ligand naturel 2'3'-cGAMP et joue un rôle inhibiteur pour empêcher l'hyperactivation de STING par la formation de polymères inactifs contenant des liaisons intermoléculaires S-S. En outre, nous avons observé que MAVS était également capable de former des polymères intermoléculaires contenant des S-S en réponse à une infection par des virus à ARN, et que l'ancrage de la protéine à la membrane était essentiel pour la formation de ces polymères. Le couplage du marquage par bioswitch à base de maléimide à l'analyse par immunoblot a confirmé que MAVS était oxydé pendant une infection avec un virus à ARN. Nous avons également constaté que des Cys situées dans des positions clés pour la formation de polymères de MAVS actifs étaient essentielles pour transduire la signalisation en aval et finalement activer le promoteur IFNβ en réponse à l'infection virale. Nos études établissent un mécanisme direct par lequel les ROS contrôlent la réponse immunitaire innée cGAS/STING et RLRs/MAVS-dépendante. Ils offrent un nouveau terrain pour la conception de thérapies ciblant des adaptateurs pertinents pour les infections virales, telles que la vaccination, mais aussi pour les troubles auto-immuns et inflammatoires. / The development of an antiviral response against viruses, including Human Immunodeficiency Virus (HIV), influenza, Respiratory Syncytial Virus (RSV) or SARS-CoV-2, relies on the activation of intracellular adaptors that ultimately lead to the production of interferons and proinflammatory cytokines. Properly balanced activation of these pathways allows the cell to mount an antiviral state, essential to restrict virus replication and spreading. Intracellular DNA viral nucleic acids can be recognized by the cyclic GMP-AMP Synthase (cGAS), which then transduces the signal through the Stimulator of Interferon Genes (STING) adaptor. On the other hand, RNA viral nucleic acids are recognized by the RIG-I-like Receptors (RLRs), which then interact with the Mitochondrial Antiviral Signaling (MAVS) adaptor. STING and MAVS are signaling hub proteins localized in membranous compartments, regulated by several posttranslational modifications (PTMs) and, upon activation, they undergo polymerization events going as far as the formation of functional aggregates. Compelling evidence supports a role of reactive oxygen species (ROS) in the regulation of STING and MAVS-dependent pathways, but the mechanisms remain ill-defined. ROS are known to modify signaling protein structure and activity through reversible oxidative PTM of Cysteines (Cys ox-PTM). Reversible Cys ox-PTMs consist of a variety of modifications, the most widely studied being S-sulfenylation (Cys-SOH), S-glutathionylation (Cys-SSG) and disulfide (S-S). To unveil the Cys ox-PTMs that affect signaling proteins involved in the antiviral response, we performed a proteome wide identification of the Cys ox-PTMs induced by ROS using maleimide-based bioswitch labeling coupled to mass spectrometry. We identified 2720 unique Cys ox-PTM sites encompassing 1473 proteins with distinct abundance, location, and functions. Among these, we uncovered the oxidation of STING at Cys148 and Cys206. The latter was inducible by oxidative stress or by the natural ligand 2’3’-cGAMP and plays an inhibitory role to prevent STING hyperactivation through the formation of inactive polymers containing intermolecular S-S bonds. Further, we observed that MAVS was also able to form intermolecular S-S containing polymers in response to RNA virus infection, and that the anchoring of the protein to the membrane was essential for these polymers to form. Maleimide-based bioswitch labeling couple to immunoblot analysis confirmed that MAVS was oxidized during RNA virus infection. We also found that Cys located in positions key for the formation of active polymers were essential for MAVS to transduce downstream signaling and ultimately activate IFNβ promoter in response to virus infection. Our studies establish a direct mechanism by which ROS control the cGAS/STING and the RLRs/MAVS-dependent innate immune response. They provide new ground for the design of therapies targeting adaptors relevant to viral infections, such as vaccination, but also to autoimmune and inflammatory disorders.
333

Vuxnas upplevelser av att leva med ledgångsreumatism : Enkvalitativ litteraturstudie / Adults’ experiences of living with rheumatoid : A qualitativeliterature review

Huynh, Tin-An, Jamous, Laila January 2023 (has links)
Bakgrund: Ledgångsreumatism (RA) är en kronisk sjukdom som primärt påverkar lederna och har en inverkan på vuxnas dagliga liv. För att uppnå en mer omfattande insikt om sjukdomen och dess konsekvenser, är det av betydelse att utforska vuxnas upplevelser av att leva med RA. Denna insikt är nödvändig för att tillhandahålla adekvat vård och tillgodose de befintliga behoven. Syfte: Syftet med litteraturstudien är att undersöka vuxnas upplevelser av att leva med RA.Metod: En litteraturöversikt baserad på 12 kvalitativa artiklar har genomförts, där urvalet fokuserar på personer över 18 år med diagnosen RA. Genom en kvalitativ metodologi samlades data hämtade från databaserna Cinahl och Pubmed. Artiklarna kvalitet granskades enligt SBU:s bedömningsmall och resultatet analyserades enligt Popenoe m.fl. analysmetodik. Resultat: 3 huvudteman framkom, dessa teman var fysisk påverkan, social påverkan och självbild. Elva subkategorier identifierades, dessa var Upplevelsen av trötthet, Upplevelsen av smärta och kronisk stelhet, Upplevelsen av kvinnors sexuella hälsan, Strategier för att hantera vardagen, Upplevelsen av familje- och vänskapsrelationer, Upplevelsen av arbetsrelationer, Upplevelsen av sexuella relationer, Strategier kring arbetsrelaterad påverkan, Upplevelsen av förändrad kropp, Upplevlesen av att vara beroende av andra och Strategier kring självbilden. Konklusion: Resultatet belyste de utmaningarna som vuxna med RA stöter på dagligen. De dagliga utmaningarna sträcker sig över de fysiska- och psykiska aspekter samt förändringar i självbilden. Vidare framkom det i studien att RA har även en påverkan på kvinnors sexuella hälsa. För grundutbildade sjuksköterskor är det av betydelse att förstå vuxnas upplevelser och deras hantering av sjukdomen. Detta för att kunna tillgodose den vård och stöd som krävs för att förbättra deras övergripande livskvalitet.
334

Urticaria in Pregnancy and Lactation

Kocatürk, Emek, Podder, Indrashis, Zenclussen, Ana C., Kasperska Zajac, Alicja, Elieh-Ali-Komi, Daniel, Church, Martin K., Maurer, Marcus 16 January 2024 (has links)
Chronic urticaria (CU) is a mast cell-driven chronic inflammatory disease with a female predominance. Since CU affects mostly females in reproductive age, pregnancy is an important aspect to consider in the context of this disease. Sex hormones affect mast cell (MC) biology, and the hormonal changes that come with pregnancy can modulate the course of chronic inflammatory conditions, and they often do. Also, pregnancy-associated changes in the immune system, including local adaptation of innate and adaptive immune responses and skewing of adaptive immunity toward a Th2/Treg profile have been linked to changes in the course of inflammatory diseases. As of now, little is known about the effects of pregnancy on CU and the outcomes of pregnancy in CU patients. Also, there are no real-life studies to show the safety of urticaria medications during pregnancy. The recent PREG-CU study provided the first insights on this and showed that CU improves during pregnancy in half of the patients, whereas it worsens in one-third; and two of five CU patients experience flare-ups of their CU during pregnancy. The international EAACI/GA²LEN/EuroGuiDerm/APAAACI guideline for urticaria recommends adopting the samemanagement strategy in pregnant and lactating CU patients; starting treatment with standard doses of second-generation (non-sedative) H1 antihistamines, to increase the dose up to 4-folds in case of no response, and to add omalizumab in antihistamine-refractory patients; but also emphasizes the lack of evidence-based information on the safety and efficacy of urticaria treatments during pregnancy. The PREG-CU study assessed treatments and their outcomes during pregnancy. Here, we review the reported effects of sex hormones and pregnancy-specific immunological changes on urticaria, we discuss the impact of pregnancy on urticaria, and we provide information and guidance on the management of urticaria during pregnancy and lactation.
335

Detection of Immune Checkpoint Receptors – A Current Challenge in Clinical Flow Cytometry

Shibru, Benjamin, Fey, Katharina, Fricke, Stephan, Blaudszun, André-René, Fürst, Friederike, Weise, Max, Seiffert, Sabine, Weyh, Maria Katharina, Köhl, Ulrike, Sack, Ulrich, Boldt, Andreas 24 March 2023 (has links)
Immunological therapy principles are increasingly determining modern medicine. They are used to treat diseases of the immune system, for tumors, but also for infections, neurological diseases, and many others. Most of these therapies base on antibodies, but small molecules, soluble receptors or cells and modified cells are also used. The development of immune checkpoint inhibitors is amazingly fast. T-cell directed antibody therapies against PD-1 or CTLA-4 are already firmly established in the clinic. Further targets are constantly being added and it is becoming increasingly clear that their expression is not only relevant on T cells. Furthermore, we do not yet have any experience with the long-term systemic effects of the treatment. Flow cytometry can be used for diagnosis, monitoring, and detection of side effects. In this review, we focus on checkpoint molecules as target molecules and functional markers of cells of the innate and acquired immune system. However, for most of the interesting and potentially relevant parameters, there are still no test kits suitable for routine use. Here we give an overview of the detection of checkpoint molecules on immune cells in the peripheral blood and show examples of a possible design of antibody panels.
336

The Aryl Hydrocarbon Receptor Regulates an Essential Transcriptional Element in the Immunoglobulin Heavy Chain Gene

Wourms, Michael J. January 2013 (has links)
No description available.
337

Rheumatoid Factor in Chronic HCV Infection is Associated with B Cell Dysregulation and Delayed Normalization after Viral Clearance but HBD-3 may Improve Host Immune Function

Reyes-Aviles, Elane 01 June 2016 (has links)
No description available.
338

Rubicon-deficiency sensitizes mice to mixed lineage kinase domain-like (MLKL)-mediated kidney ischemia-reperfusion injury

Tonnus, Wulf, Locke, Sophie, Meyer, Claudia, Maremonti, Francesca, Eggert, Lena, Mässenhausen, Anne von, Bornstein, Stefan R., Green, Douglas R., Linkermann, Andreas 22 May 2024 (has links)
The cytosolic protein rubicon (RUBCN) has been implicated in the removal of necrotic debris and autoimmunity. However, the role of RUBCN in models of acute kidney injury (AKI), a condition that typically involves necrotic kidney tubules, was not investigated. Here, we demonstrate that RUBCN-deficient mice are hypersensitive to renal damage induced by ischemia-reperfusion injury (IRI) and cisplatin-induced AKI. Combined deficiency of RUBCN and mixed lineage kinase domain-like (MLKL) partially reversed the sensitivity in the IRI model suggesting that the absence of RUBCN sensitizes to necroptosis in that model. Necroptosis is known to contribute to TNFα-induced severe inflammatory response syndrome (SIRS), but we detected no statistically significant difference in overall survival following injection of TNFα in RUBCN-deficient mice. We additionally generated RUBCN-deficient mice which lack gasdermin D (GSDMD), the terminal mediator of pyroptosis, but no reversal of the AKI phenotype was observed. Finally, and in contrast to the previous understanding of the role of RUBCN, we did not find a significant autoimmune phenotype in RUBCN-deficient mice, but detected chronic kidney injury (CKD) in aged RUBCN-deficient mice of both sexes. In summary, our data indicate that RUBCN-deficient mice are hypersensitive to kidney injury.
339

Intrazelluläre Stressmechanismen in Fibroblasten von Patienten mit myotoner Dystrophie

Eberl, Nadia 03 June 2024 (has links)
Die myotone Dystrophie ist eine autosomal dominant vererbte, multisystemische Erkrankung mit skelettmuskulärem Fokus und wird in zwei Untergruppen eingeteilt, die myotone Dystrophie Typ I (MD1), verursacht durch eine CTG-Trinukleotidexpansion im DMPK-Gen auf Chromosom 19, und die myotone Dystrophie Typ II (MD2), verursacht durch eine Tetranukleotidexpansion im CNBP-Gen auf Chromosom 3. Die Nukleotidexpansionen akkumulieren als mRNA intranukleär und tragen über die Beeinflussung des alternativen Splicings von über 30 Genen zum Erkrankungsmechanismus bei. Daneben akkumulieren die mRNA-Repeats im Zytoplasma und induzieren über die Repeat-assoziierte-non-AUG-Translation (RAN-Translation) die Akkumulation aberranter Proteine. Wenngleich die Patienten der MD2 einen milderen Krankheitsverlauf erleben, zeigen sie ein erhöhtes Auftreten von Autoimmunerkrankungen. In der Pathogenese der Autoimmunerkrankungen spielt die durch Interferon-Typ-I vermittelte Immunreaktion eine wichtige Rolle. In der AG Günther konnte eine erhöhte Expression interferonstimulierter Gene und die erhöhte Expression von Markern des Stresszustandes des endoplasmatischen Retikulums in Fibroblasten von MD2-Patienten nachgewiesen sowie die erhöhte Prävalenz von Autoimmunerkrankungen in MD2 gezeigt werden. Die Auswertung serologischer Parameter im Rahmen dieser Arbeit erlaubte eine klinische Charakterisierung der Patienten und ergab einen positiven Zusammenhang zwischen Höhe der Myoglobin-Konzentration im Serum und Länge der CCTG Repeats. Es wurde die Hypothese aufgestellt, dass die zytoplasmatischen RNA-Repeats über die RAN-Translation und Akkumulation aberranter Proteine zur Induktion von ER-Stress führen, welcher über die gemeinsame Kontaktflächen der Mitochondrien-assoziierten Membranen (MAMs) in die Mitochondrien übertragen wird. Im Rahmen des mitochondrialen Stresszustandes könnte es zu einer Freisetzung mitochondrialer DNA und zur Aktivierung des zytosolischen DNA-Rezeptors cGAS und einer nachfolgenden Expression von Interferon und Interferon-stimulierten Genen kommen, die für das vermehrte Auftreten der Autoimmunerkrankungen verantwortlich sind. Zur Überprüfung der Hypothese sollte nach Analyse der Proteinexpression der ER-Stress-Marker eIF2α und peIF2α eine Hemmung der ER-Stressreaktion vorgenommen werden. Die anschließende Untersuchung des mitochondrialen Stresszustandes und die Unterbrechung der MAMs sollte Aufschluss über die Rolle der Mitochondrien in der Pathogenese der Autoimmunität liefern. In dieser Arbeit konnte die erhöhte Expression des ER-Stressmarkers peIF2α nach Stressinduktion in Fibroblasten von MD2-Patienten gezeigt werden. Dies könnte auf eine Sensibilisierung des Signalweges im Rahmen eines chronischen Stresszustandes hinweisen. Der Versuch einer Behandlung der Fibroblasten mit Ursodesoxycholsäure (UDCA), einem chemischen Chaperon, mit Ziel der Suppression der ER-Stressreaktion erzielte keine Reduktion der Expression der ER-Stressmarker unter Nativniveau. Nach Stimulation des ER-Stresses konnte mit UDCA-Vorbehandlung dennoch die Reduktion auf Nativniveau erzielt werden. Zur Analyse des mitochondrialen Stresszustandes wurde eine Färbung mit Mitotracker-Farbstoffen und anschließender Durchflusszytometrie und eine Messung der reaktiven Sauerstoffspezies (ROS) vorgenommen, welche ein verringertes mitochondriales Membranpotential und eine erhöhte ROS-Expression in den MD2-Fibroblasten ergaben und mit einem mitochondrialen Stresszustand einhergehen könnten. Nach Unterbrechung der räumlichen Verbindung zwischen ER und Mitochondrium durch die Herunterregulation des gemeinsamen Strukturproteins PERK konnten Hinweise auf eine verringerte ROS-Expression in den MD2-Fibroblasten gefunden werden. Die Ergebnisse dieser Arbeit unterstützen die Hypothese der Funktion der mitochondrialen Stressreaktion in den Fibroblasten der MD2-Patienten, wenngleich die Autoimmunität-vermittelnden Mechanismen noch Gegenstand weiterführender Untersuchungen sein sollten.
340

Phenotypic Variability in a Family with Aicardi-Goutières Syndrome Due to the Common A177T RNASEH2B Mutation

Tüngler, Victoria, Schmidt, Franziska, Hieronimus, Steve, Reyes-Velasco, Claudio, Lee-Kirsch, Min Ae 09 July 2014 (has links) (PDF)
Aicardi-Goutières syndrome (AGS) is a rare inflammatory encephalopathy mimicking in utero acquired viral infection. Cardinal findings comprise leukodystrophy, basal ganglia calcifications and cerebral atrophy along with cerebrospinal fluid lymphocytosis and elevated interferon-α. In the majority of cases AGS is inherited as an autosomal recessive trait and caused by mutations in six genes including RNASEH2A, RNASEH2B, RNASEH2C, TREX1, SAMHD1 and ADAR1, all of which encode enzymes acting on nucleic acid species. Most patients present with first neurological signs in early infancy and experience severe global developmental delay. Here, we report on the unusual divergent phenotype of two siblings who both carry the most frequent AGS causing p.A177T (c.529G > A) RNASEH2B mutation in the homozygous state. While one sibling showed a typical AGS presentation with early onset and severe statomotor and mental impairment, the older sibling was intellectually completely normal. She was only diagnosed because of mild spasticity of the legs and serological signs of autoimmunity. These findings highlight the phenotypic variability of AGS and suggest that AGS may be underdiagnosed among children with mild cerebral palsy.

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