• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 281
  • 110
  • 41
  • 33
  • 22
  • 21
  • 18
  • 16
  • 7
  • 5
  • 3
  • 3
  • 3
  • 2
  • 2
  • Tagged with
  • 688
  • 144
  • 126
  • 126
  • 102
  • 68
  • 59
  • 54
  • 50
  • 50
  • 48
  • 47
  • 46
  • 45
  • 45
  • 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.
681

Estudo dos mecanismos induzidos pelo treinamento físico aeróbico ao longo do tempo na inflamação pulmonar e no remodelamento brônquico em um modelo murino de asma / Study of the mechanisms induced by aerobic training over time in pulmonary inflammation and bronchial remodeling in an asthma murine model

Ronaldo Aparecido da Silva 09 August 2013 (has links)
O treinamento aeróbico (TA) traz benefícios para os asmáticos, porém os mecanismos antiinflamatórios não são conhecidos. Estudos experimentais de asma têm mostrado que o TA reduz a inflamação pulmonar alérgica crônica (IPAC) e a reposta Th2, no entanto, nenhum estudo explicou quando os efeitos protetores são iniciados e qual é a principal via anti-inflamatória desencadeada. Objetivo: Avaliar o efeito do TA ao longo do tempo em um modelo murino de asma visando identificar quando são iniciados os efeitos anti-inflamatórios e a reversão do remodelamento brônquico (RB). Métodos: BALB/c (160 animais) foram divididos em 4 grupos: Controle (CT): não induzidos à IPAC e não treinados; Treinamento Aeróbico (TA): não induzidos à IPAC e treinados; OVA: induzidos à IPAC e não treinados; OVA+TA: induzidos à IPAC e treinados. Em seguida foram criados outros subgrupos 1, 3, 7, 15 e 30 dias de TA, ou seja, cada grupo foi repetidos 5 vezes para investigação do efeito do TA ao longo do tempo. Os grupos OVA foram sensibilizados com i.p. (OVA+HidroxAlum), após foram induzidos à IPAC com aerosol de OVA (1-3%) iniciado no dia 21 (3 x semana; 30 min./sessão). A adaptação ao TA foi realizada entre os dias 21 a 23, no dia 25 foi realizado o teste físico, no dia 28 o TA foi iniciado (50% intensidade, frequência 5 x, por 4 semanas). Vinte quatro horas da ultima sessão de TA (1, 3, 7, 15 e 30 dias) os animas foram anestesiados, eutanizados e coletados o lavado broncoalveolar (LBA) (contagem celular total e diferencial), sangue para quantificação das imunoglobulinas (IgE e IgG1) por técnica de reação de anafilaxia cutânea passiva (PCA), o tecido pulmonar para avaliação dos mediadores: IL-4, IL-5, eotaxina, RANTES, ICAM-1, VCAM-1, TGF-b, VEGF, Osteopontina (OPN), NF-kB, FOXP3, receptor de glicocorticóide (RG) e anti-inflamatórias IL-10 e IL-1ra (imunohistoquímica e quantificação por morfometria) e foi coletado também o músculo quadríceps para avaliação da produção das miocinas (IL-10, IL-1ra e IL-6) (imunohistoquímica e quantificado por análise de imagem). O RB (músculo liso, epitélio, deposições das fibras de colágeno e elástica e produção de muco) também foi avaliado por análise de imagem. Resultados: Não foi observada produção das miocinas (p>0,05). Os níveis de IgE, IgG1, migração celular, produção dos mediadores inflamatórios e o RB foram aumentados nos grupos OVA (p<0,05), que ainda mostraram redução da produção do RG (p<0,05). O TA aumentou o RG no músculo liso das vias aéreas, as produções de IL-10 e IL- 1ra aumentaram a partir do 7º dia por células peribrônquicas, ao mesmo tempo que foram reduzidos o NF-kB, IL-4, IL-5, eotaxina, RANTES, ICAM-1, VCAM-1, VEGF, eosinófilos no LBA e foram revertidos o espessamento do músculo liso, do epitélio e as deposições de fibras de colágeno (p<0,05). Curiosamente, a diminuição de TFG-b ocorreu após o 3º dia, enquanto OPN, elástica e muco ocorreram após 15 dias de TA, enquanto IgE, IgG1 e neutrófilos apenas foram reduzidas ao final de 30 dias (p<0,05). Conclusão: A partir do 3º dia do TA foi iniciado o mecanismo anti-inflamatório pelo aumento do RG no músculo liso das vias aéreas, seguido pelo aumento de IL-10 e IL-1ra e pela redução de NF-kB a partir do 7º dia do TA, efeitos que reverteram a inflamação alérgica crônica e o RB / The aerobic training (AT) promotes benefits for asthmatics, but the anti-inflammatory mechanisms are not known. Experimental studies of asthma have shown that AT reduces the pulmonary allergic chronic inflammation (PACI) and response Th2, however no study has ever explained when the protective effects are initiated and which is the main anti-inflammatory pathway triggered. Aim: To evaluate the effect of AT over time in a murine model of asthma to identify when the anti-inflammatory effects is started and reverse bronchial remodeling (BR). Methods: BALB/c (160 mice) were divided into 4 groups: Control (CT): not induced to PACI and untrained; Aerobic Training (TA): not induced to PACI and trained; OVA: induced to PACI and untrained; OVA + TA: induced to PACI and trained. After that were created others subgroups 1, 3, 7, 15 and 30 days AT, that is, each group was repeated 5 times to investigate the effect of AT over time. The OVA groups were sensitized with i.p. OVA (OVA+AlumHidrox), and then the mice were induced after the PACI with aerosol of OVA (1-3%) started on the 21st day (3 x week, 30 min./Session). Adaptation to TA was held between 21-23, on the 25th day the physical test was performed, and on day 28 AT was begun (50% intensity, frequency x 5 for 4 weeks). Twenty four hours of the after last session of AT (1, 3, 7, 15 and 30 days) the mice were anesthetized, euthanized and the bronchoalveolar lavage fluid was collected (BALF) (Total and differential cell count) and blood was used to quantify immunoglobulins (IgE and IgG1) by passive cutaneous anaphylaxis reaction (PCA) technique, the pulmonary tissue was removed and used to evaluate the mediators IL-4, IL-5, eotaxin, RANTES, ICAM-1, VCAM-1, TGF-b, VEGF, osteopontin (OPN), NF-kB, FOXP3, glucocorticoid receptor (GR), and antiinflammatory IL-10 and IL-1ra (immunohistochemistry and quantified by morphometry), was also the quadriceps muscle to assess the expression of myokines (IL-10, IL-1ra and IL-6) (by immunohistochemistry and image analyses). The BR (smooth muscle, epithelium, collagen and elastic fibers deposition, and mucus production) was also evaluated by image analysis. Results: It was not observed any production of myokines (p>0.05). The levels of IgE and IgG1, cell migration, production of inflammatory mediators, and the BR were increased in the OVA groups (p<0.05); that still showed a decreased production of the GR (p<0.05). The AT promoted an increase of GR in the airway smooth muscle from the 3rd day, the production of IL-10 and IL- 1ra were increased from day 7 for cells peribronchial, while NF-kB, IL-4, IL-5, eotaxin, RANTES, ICAM-1, VCAM-1, VEGF, eosinophil counting in BALF were reduced, and reversed the smooth muscle thickening, epithelium and deposition of collagen fibers too (p<0.05). Interestingly, the decreasing of TGF-b occurred in the 3rd day, and OPN, elastic fibers, mucus occurred after 15 days of AT, while IgE and IgG1, and neutrophils were reduced only after 30 days (p<0.05). Conclusion: The anti-inflammatory mechanism by increasing the GR on the smooth muscle of the airways was initiated from the 3rd day of the AT, followed by an increase of IL-10 and IL-1ra and a reduction of NF-kB from the 7th day of the AT, reversed the effects of chronic allergic inflammation and bronchial remodeling
682

En app för smartare måltidsplanering

Perjus, Victoria January 2013 (has links)
This thesis is based on design theory about how to build an application for the mobile platform, a scientific analysis and an application for grocery shopping and meal planning. The thesis also contains a valuation of the research and of the application. The valuation of the application was done by a usability test and an analysis of the results of the test. The application of the thesis has an easy navigation system, which is time saving and simple to use. Finding recipes with the associated ingredients is a quick fix. The search function can be used for searching freely after recipes as well as for separate ingredients. That makes it possible for the user to create own recipes from available ingredients. One can also compose a recipe from scratch and add to the recipe bank. It´s also possible to see which ingredients that is needed for a certain recipe. The application is direct and easy to use and because of that it can be used outside the home in environments where there are a lot of distractions, for example in the food store, where all the ingredients is purchased and checked off from the list. The application is competent. The user can save recipes and create own recipes without having to login. From the added information the app is able to suggest menus, at the same time it enables for the user to compose his or her own menus with lunch and dinner. Gradually a big and varying recipe bank is built which is formed after the family´s specific priorities of good, easy to cook, healthy food and it also sends a warning if a recipe contains food that someone in the family is allergic to. Each and every recipe can also be illustrated with drawings which could improve the overview. The application can be synced with a web site where more information can be extracted. / Den här uppsatsen består av en designteori för hur en applikation för den mobila plattformen ska byggas, samt en vetenskaplig analys och en färdig applikation som ska användas vid inköp av mat och planering av måltider. Uppsatsen innehåller också en utvärdering av forskningen och av applikationen. Utvärderingen av applikationen utfördes genom en användarbarhetstestning och en analys av testningens resultat. Uppsatsens applikation en har smidig navigering, som är tidseffektiv och enkel att använda. Det går snabbt att ta fram recept och vilka ingredienser som krävs för receptet. Det är möjligt att söka fritt både på recept och enskilda ingredienser. Det innebär att användaren kan forma egna recept utifrån tillgängliga ingredienser. Man kan även komponera egna recept och lägga in i receptbanken. Det är också möjligt att se vilka ingredienser som behövs för att ett visst recept ska kunna tillagas. Applikationen är tydlig och lättanvänd och fungerar därför i miljöer med många distraherande inslag utanför hemmet, exempelvis direkt i butiken, där alla ingredienser kan köpas in och bockas av från en lista. Applikationen är kompetent. Användaren kan spara recept och lägga till egna recept utan att behöva logga in. Med utgångspunkt från inlagd information kan applikationen föreslå menyer, samtidigt som den möjliggör komposition av egna menyer för lunch och middag.  Efter hand byggs det upp en stor och varierande receptbank som formas efter familjens egna prioriteringar av god, lättlagad, nyttig mat och även varnar för exempelvis mat som kan framkalla allergireaktioner om allergi förekommer i familjen. Vart och en av recepten kan också illustreras med tecknade bilder vilket skulle kunna förbättrar överblicken. Applikationen kan samsynkas med en hemsida där mer utförlig information kan hämtas.
683

Early risk factors influencing lung function in schoolchildren born preterm in the era of new bronchopulmonary dysplasia

Ronkainen, E. (Eveliina) 01 November 2016 (has links)
Abstract Advances in perinatal treatment practices—such as antenatal corticosteroids, surfactant replacement therapy, and gentler ventilator modalities—have improved the survival of infants born preterm. Consequently, later morbidity and pulmonary outcome for survivors has attracted increasing interest. The incidence of bronchopulmonary dysplasia (BPD) remains high and the condition is manifesting in infants born at earlier gestational weeks than before. This so-called new BPD results from the arrest of alveolar development and is associated with less structural airway injury and interstitial fibrosis than previously. Long-term follow-up data on lung function, lung structure and respiratory morbidity of children treated with modern methods is insufficiently known. We performed a follow-up study of 88 preterm-born children and 88 matched term-born controls at school age. Children born preterm had lower values in lung function measurements than term-born peers. Reductions were most marked in those with a history of BPD. In accordance with the foetal origins hypothesis, children with intrauterine growth restriction (IUGR) had lower lung function than gestation-controls. This indicates that poor growth in utero is an additional burden on pulmonary health. Both IUGR and BPD predicted lower lung function independently. High-resolution computed tomography of the lung was obtained from 21 children with a history of BPD. Structural abnormalities were common, children with severe BPD being most affected. Preterm children were hospitalised more often than controls, mainly because of wheezing disorders. However, BPD did not influence the hospitalisations. According to the meta-analysis of the contemporary data available, the respiratory outcome of children who had only mild BPD may have improved in comparison to old follow-up data, whereas the results for those without BPD or moderate-to-severe BPD have remained remarkably stable despite progress in treatment practices during early life. In conclusion, preterm children had subtle impairments in lung function at school age. Although they were fairly asymptomatic, concern about the possible long-term effects of preterm birth on pulmonary health is justified. It has been proposed that BPD may predispose individuals to an early COPD-like disorder. Preterm children must be protected from any additional burden on respiratory health and should be monitored appropriately for early detection of lung disease. / Tiivistelmä Keskosten tehohoito on kehittynyt viime vuosikymmeninä merkittävästi, ja yhä epäkypsempänä syntyvät keskoset selviävät hengissä syntymän jälkeen. Keskosten pitkäaikainen keuhkosairaus, bronkopulmonaalinen dysplasia (BPD), on perinteisesti johtunut hengityskonehoidon ja happikaasun aiheuttamasta keuhkovauriosta ja johtanut keuhkokudoksen arpeutumiseen. Aiempaa ennenaikaisemmilla keskosilla esiintyy kuitenkin nykyään niin sanottua uutta BPD:tä, jonka ajatellaan johtuvan enemmän keuhkorakkuloiden kehityshäiriöstä kuin hoitojen aiheuttamasta keuhkovauriosta. Selvitimme, miten nykyaikaisilla menetelmillä hoidettujen keskosten keuhkojen rakenne ja toiminta kehittyvät kouluikään mennessä. Seurantatutkimukseemme osallistui 88 ennenaikaisena syntynyttä, kouluikään ehtinyttä lasta ja 88 täysiaikaisena syntynyttä, kaltaistettua verrokkia. Keskosena syntyneiden lasten keuhkofunktio oli kouluiässä huonompi kuin täysiaikaisena syntyneiden verrokkien. Alhaisin keuhkofunktio oli niillä keskosena syntyneillä lapsilla, jotka olivat sairastaneet vastasyntyneenä BPD:n. Myös kohdunsisäiseen kasvuhäiriöön (intrauterine growth restriction, IUGR) liittyi alentunut keuhkofunktio. BPD ja IUGR ennustivat alentunutta keuhkofunktiota toisistaan riippumatta. Tutkimuksessa tehtiin myös keuhkojen ohutleiketietokonekuvaus 21 keskoselle, jotka olivat sairastaneet BPD:n. Lähes kaikilla havaittiin poikkeavia löydöksiä – eniten niillä, joilla oli ollut vastasyntyneenä BPD:n vaikea tautimuoto. Keskosina syntyneet joutuivat kahden ensimmäisen vuoden aikana verrokkeja useammin sairaalahoitoon. Yleisimpiä syitä olivat hengityksen vinkumista aiheuttavat taudit kuten ilmatiehyttulehdus, ahtauttava keuhkoputkitulehdus tai akuutti astmakohtaus. Vastasyntyneenä sairastettu BPD ei kuitenkaan lisännyt todennäköisyyttä joutua sairaalahoitoon. Tutkimuksessa tehtiin myös meta-analyysi nykyaikaisilla menetelmillä hoidettujen keskosten keuhkofunktiosta: lievää BPD:tä sairastavien tulokset näyttävät parantuneen, kun taas keskivaikeaa tai vaikeaa tautimuotoa sairastavien ja ilman BPD:tä selvinneiden keuhkofunktio ei ole muuttunut uusien hoitojen myötä. Yhteenvetona voidaan todeta, että keskosten keuhkojen toimintakyky on jonkin verran alentunut täysiaikaisiin verrattuna. Lievästi alentunut keuhkofunktio ei kuitenkaan yleensä aiheuttanut koululaisille oireita. Keskosena syntyneiden lasten hengityselinten toimintaa on syytä seurata, sillä niin sanotun uuden BPD:n pitkäaikaisesta ennusteesta ei ole vielä tietoa.
684

Endothelial FasL in lymph nodes and in intestinal lymphatic tissue

Kokkonen, T. (Tuomo) 29 March 2016 (has links)
Abstract The function of the transmembrane protein FasL is to complex with the Fas receptor in a target cell and induce target cell apoptosis. Fas/FasL-mediated apoptosis plays important role in immunoregulation. FasL expression is mostly seen in activated lymphocytes. We have characterized endothelial FasL expression in different functional compartments of lymph nodes and gut-associated lymphoid tissue. Furthermore, we have explored the functional role of endothelial FasL expression by analyzing correlation with apoptosis of lymphocyte subpopulations in lymph nodes and by assessing endothelial expression under different conditions by activation of immune functions in gastrointestinal mucosa. Immunohistochemical stainings (Fas, FasL, CD3, CD20, CD19, CD23, CD56, FVIII) were performed on 20 reactive lymph node tissues (I and II), 60 pediatric endoscopy biopsy samples (III) or 60 samples from gut resections (IV). A double-staining method combining apoptosis detection with the TUNEL-method and lymphocyte classification with FasL, Fas and cell lineage markers was optimized. Patient groups included non-pathological lymph nodes, pediatric cow’s milk-sensitive enteropathy, pediatric celiac disease, appendicitis, ulcerative colitis and Crohn’s disease. Control groups included normal biopsy samples from pediatric patients and non-pathological resecate samples from the appendix, colon or ileum to correspond to patient groups. Quantitative analysis (positive vessels or cells per mm2) was performed thoroughly for each anatomical region. In a subset of patients, soluble FasL in the serum was quantified with standard enzyme-linked immunosorbent assay. In reactive lymph nodes FasL expression was predominantly present in high endothelial venules located in the paracortical area, where apoptotic T and B lymphocytes, some expressing Fas, were subsequently found. In the gut wall vascular FasL expression was seen in high endothelial vessels near lymphoid follicles. Serum FasL was elevated in children with an abundance of mucosal lymphoid follicles. In IBD, vascular FasL was upregulated in ulcers and in the submucosa of colons affected by Crohn’s disease. The results indicate that endothelial FasL is characteristically present in high endothelial venules of lymphoid tissues. Detection of apoptotic Fas expressing lymphocytes adjacent to such vessels supports the idea that endothelial FasL functions as a selective gatekeeper by inducing apoptosis of Fas+ lymphocytes entering from the blood stream. / Tiivistelmä Solukalvon läpäisevän proteiinin, FasL:n, tehtävä on sitoutua kohdesolun Fas-reseptoriin ja indusoida kohdesolun apoptoosi. Fas/FasL-välitteinen apoptoosi on merkittävä tekijä immunologisessa säätelyssä. FasL ilmentyy pääsääntöisesti aktivoituneissa lymfosyyteissä. Olemme kuvanneet tutkimuksessamme FasL:n endoteelistä ilmentymistä imukudoksen eri toiminnallisissa alueissa ja suoliston lymfaattisessa kudoksessa. Lisäksi kartoitimme endoteelin FasL:n toiminnallista merkitystä analysoimalla sen yhteyttä lymfosyyttien alaryhmien apoptoosiin imusolmukkeissa ja arvioimalla FasL:n endoteelistä ilmentymistä suoliston limakalvon immunologisesti erilaisissa sairauksissa. Teimme immunohistokemiallisia värjäyksiä (Fas, FasL, CD3, CD20, CD19, CD23, CD56 ja FVIII) 20 reaktiiviselle imusolmukkeelle (I ja II), 60 lapsen endoskooppiselle biopsianäytteelle (III) sekä 60 suoliresekaattinäytteelle (IV). Optimoimme kaksoisvärjäysmenetelmän, missä yhdistettiin apoptoosin havainnointimenetelmä TUNEL ja FasL-, Fas- tai solulinjamarkkeri. Potilasryhmiin kuului potilaita, joilla oli normaalit imusolmukkeet, sekä potilaita, jotka sairastivat lasten viivästynyttä lehmänmaitoallergiaa, lasten keliakiaa, umpilisäketulehdusta, haavaista paksusuolitulehdusta tai Crohnin tautia. Verrokkiryhmiin kuului normaaleja biopsianäytteitä lapsipotilailta sekä terveitä resekaattinäytteitä umpilisäkkeestä sekä paksu- tai sykkyräsuolesta potilasryhmien mukaisesti. Jokaiselle anatomiselle alueelle suoritimme perusteellisen määrällisen analyysin (positiivista suonta tai solua per mm2). Osalle ryhmistä suoritimme seerumin liukoisen FasL:n määrityksen entsyymivälitteisellä immunosorbenttimäärityksellä. Reaktiivisissa imusolmukkeissa FasL:n ilmentyminen näkyi pääsääntöisesti parakortikaalialueen korkeaendoteelisissä venuleissa, missä myös apoptoottiset T- ja B-lymfosyytit (joista osa ilmensi Fasia) sittemmin näkyivät. Suoliston seinämässä havaitsimme verisuoniperäistä FasL:n ilmentymistä korkeaendoteelisissä suonissa lymfaattisten itukeskusten lähettyvillä. Niillä lapsipotilailla, joilla havaitsimme limakalvon lymfaattisten itukeskuksien lisääntymistä, oli myös seerumin FasL-pitoisuus koholla. Tulehduksellisissa suolistosairauksissa verisuoniperäinen FasL oli lisääntynyt limakalvon haavaumissa sekä Crohnin tautia sairastavien potilaiden submukoosassa. Tulokset osoittavat verisuoniperäisen FasL:n tyypillisesti ilmentyvän imukudoksen korkeaendoteelisissa suonissa. Apoptoosin havaitseminen Fasia ilmentävissä lymfosyyteissä näiden suonien läheisyydessä tukee ajatusta siitä, kuinka verisuoniperäinen FasL toimii valikoivana portinvartijana ja aiheuttaa Fas-positiivisten lymfosyyttien apoptoosin estämällä niiden pääsyn verenkierrosta.
685

Pharmacist educational outreach for improved primary care of asthma in children

Bheekie, Angeni January 2001 (has links)
Doctor Pharmaceuticae - DPharm / Underdiagnosis and undertreatment of asthma in children are barriers to optimal health care delivery and health, incurring substantial costs to both the families and health services. A tailored multifaceted educational outreach intervention ("academic detailing") was designed and implemented among private sector general practitioners (GPs) serving a poor working class urban community in Cape Town, South Africa. The intervention aimed to improve primary care childhood asthma by promoting the adoption of guideline-based key messages. The effectiveness of the intervention was tested in a randomised controlled trial, Chestiness and Asthma in Mitchell's Plain (CHAMP) (Zwarenstein 1999). This thesis describes the design, implementation and qualitative evaluation of the outreach intervention. Methods Qualitative interviews and quantitative sample surveys were conducted among GPs to identify and measure the prevalence of perceived barriers to optimal asthma care in children. A trained pharmacist visited GPs twice, promoting eight evidence-based primary care messages to overcome barriers to optimal care for asthma in children. The messages focused on key diagnostic indicators, a treatment algorithm based on severity, cost of drug therapies, inhaler and spacer use, and preventive treatment. These messages were formatted into attractive promotional material. The first visit promoted use of the messages, the second reinforced adoption in routine practice and assessed GPs' responses using unobtrusive qualitative data collection methods. The dialogue was tailored to each GP's needs. Results Thirty-two GPs received the intervention. All but one consented to both visits. At the first visit responses were varied. A few GPs were confused or suspicious; most were in agreement with the messages but seemed passive towards implementation; a few were keen to adopt the messages into their routine practice. Response at first visit was not predictive of use as assessed at the second. At the second visit, most GPs claimed that they personally agreed with and used the messages, with a large minority less enthusiastic. Conclusion The intervention appears to have been broadly accepted as evident from GPs' acceptance of the outreach pharmacist, but reports of complete adoption of the messages and use of the kit were less prevalent. This finding is consistent with and helps to explain the improved health outcomes of children with asthma in the CHAMP trial. The combination of qualitative and quantitative research methods was effective in identifying and assessing GPs' barriers. Further, the combination helped to confirm the determinants for the intervention. Unobtrusive qualitative methods provided valuable insight into GP behaviour in routine setting. Additional studies conducted in public sector pnmary care settings and for other diseases are needed to confirm the wider acceptability and effectiveness of multifaceted outreach interventions aimed at improving professional practice. Such an intervention in our study setting seemed successful for childhood asthma.
686

Differential functions of Interleukin-10 derived from different cell types in the regulation of immune responses

Surianarayanan, Sangeetha 16 December 2011 (has links)
Interleukin-10 (IL-10) is an important regulator of immune responses secreted by different cell types. Previous results from our group suggested that the biological effects of this cytokine critically depend on its cellular source. Recent studies reported IL-10 dependent immunosuppressive functions of a specialized subset of regulatory B cells and mast cells. These results relied on adoptive cell transfers, a technique which can potentially introduce artifacts. Therefore, we aimed to readdress these questions in independent models using IL-10 transcriptional reporter mice and various conditional IL-10 mutant mice. Findings in IL-10 reporter system suggested prominent IL-10 transcription in regulatory B cells upon LPS administration. Exposure of mice to contact allergen revealed robust reporter expression in CD8 T cells, moderate to mild reporter expression in CD4 T cells and dendritic cells (DC) respectively, and lack of reporter expression in B cells, mast cells and NK cells in allergen challenged ears. We generated cell-type specific IL-10 mutants by Cre/LoxP-mediated conditional gene inactivation. Efficiency and specificity of Cre-mediated recombination was demonstrated by Southern blot and PCR methods. Various immunogenic challenges in conditional IL-10 mutants did not reveal a role for B cell-derived IL-10 in restraining innate TLR or T cell-dependent inflammatory responses. Likewise, mice with selective inactivation of the il10 gene in mast cells exhibited normal CHS responses and unaltered immune response to CpG oligodeoxynucleotides. On the other hand, DC-specific IL-10 mutants developed excessive inflammatory responses to contact allergens, while innate responses to TLR ligands were not altered. This indicates a non-redundant role for DC-derived IL-10 in contact allergy. Thus, the conditional IL-10 ‘‘knockout’’ mice combined with the novel transcriptional IL-10 reporter system can serve as ideal tools to understand the cell-type specific contributions to IL-10-mediated immune regulation.
687

Development and stability of IL-17-secreting T cells

Glosson, Nicole L. January 2014 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / IL-17-producing T cells are critical to the development of pathogen and tumor immunity, but also contribute to the pathology of autoimmune diseases and allergic inflammation. CD8+ (Tc17) and CD4+ (Th17) IL-17-secreting T cells develop in response to a cytokine environment that activates Signal Transducer and Activator of Transcription (STAT) proteins, though the mechanisms underlying Tc17/Th17 development and stability are still unclear. In vivo, Tc17 cells clear vaccinia virus infection and acquire cytotoxic potential, that is independent of IL-17 production and the acquisition of IFN-γ-secreting potential, but partially dependent on Fas ligand, suggesting that Tc17-mediated vaccinia virus clearance is through cell killing independent of an acquired Tc1 phenotype. In contrast, memory Th cells and NKT cells display STAT4-dependent IL-23-induced IL-17 production that correlates with Il23r expression. IL-23 does not activate STAT4 nor do other STAT4-activating cytokines induce Il23r expression in these populations, suggesting a T cell-extrinsic role for STAT4 in mediating IL-23 responsiveness. Although IL-23 is important for the maintenance of IL-17-secreting T cells, it also promotes their instability, often resulting in a pathogenic Th1-like phenotype in vitro and in vivo. In vitro-derived Th17 cells are also flexible when cultured under polarizing conditions that promote Th2 or Th9 differentiation, adopting the respective effector programs, and decreasing IL-17 production. However, in models of allergic airway disease, Th17 cells do not secrete alternative cytokines nor adopt other effector programs, and remain stable IL-17-secretors. In contrast to Th1-biased pro-inflammatory environments that induce Th17 instability in vivo, during allergic inflammatory disease, Th17 cells are comparatively stable, and retain the potential to produce IL-17. Together these data document that the inflammatory environment has distinct effects on the stability of IL-17-secreting T cells in vivo.
688

Action in Chronic Fatigue Syndrome: an Enactive Psycho-phenomenological and Semiotic Analysis of Thirty New Zealand Women's Experiences of Suffering and Recovery

Hart, M J Alexandra January 2010 (has links)
This research into Chronic Fatigue Syndrome (CFS) presents the results of 60 first-person psycho-phenomenological interviews with 30 New Zealand women. The participants were recruited from the Canterbury and Wellington regions, 10 had recovered. Taking a non-dual, non-reductive embodied approach, the phenomenological data was analysed semiotically, using a graph-theoretical cluster analysis to elucidate the large number of resulting categories, and interpreted through the enactive approach to cognitive science. The initial result of the analysis is a comprehensive exploration of the experience of CFS which develops subject-specific categories of experience and explores the relation of the illness to universal categories of experience, including self, ‘energy’, action, and being-able-to-do. Transformations of the self surrounding being-able-to-do and not-being-able-to-do were shown to elucidate the illness process. It is proposed that the concept ‘energy’ in the participants’ discourse is equivalent to the Mahayana Buddhist concept of ‘contact’. This characterises CFS as a breakdown of contact. Narrative content from the recovered interviewees reflects a reestablishment of contact. The hypothesis that CFS is a disorder of action is investigated in detail. A general model for the phenomenology and functional architecture of action is proposed. This model is a recursive loop involving felt meaning, contact, action, and perception and appears to be phenomenologically supported. It is proposed that the CFS illness process is a dynamical decompensation of the subject’s action loop caused by a breakdown in the process of contact. On this basis, a new interpretation of neurological findings in relation to CFS becomes possible. A neurological phenomenon that correlates with the illness and involves a brain region that has a similar structure to the action model’s recursive loop is identified in previous research results and compared with the action model and the results of this research. This correspondence may identify the brain regions involved in the illness process, which may provide an objective diagnostic test for the condition and approaches to treatment. The implications of this model for cognitive science and CFS should be investigated through neurophenomenological research since the model stands to shed considerable light on the nature of consciousness, contact and agency. Phenomenologically based treatments are proposed, along with suggestions for future research on CFS. The research may clarify the diagnostic criteria for CFS and guide management and treatment programmes, particularly multidimensional and interdisciplinary approaches. Category theory is proposed as a foundation for a mathematisation of phenomenology.

Page generated in 0.0372 seconds