52 research outputs found
Imago Mundi: as instruçÔes de viagem como educação do olhar e revelação do mundo, séculos XVIII e XIX
The development and validation of a scoring tool to predict the operative duration of elective laparoscopic cholecystectomy
Background: The ability to accurately predict operative duration has the potential to optimise theatre efficiency and utilisation, thus reducing costs and increasing staff and patient satisfaction. With laparoscopic cholecystectomy being one of the most commonly performed procedures worldwide, a tool to predict operative duration could be extremely beneficial to healthcare organisations.
Methods: Data collected from the CholeS study on patients undergoing cholecystectomy in UK and Irish hospitals between 04/2014 and 05/2014 were used to study operative duration. A multivariable binary logistic regression model was produced in order to identify significant independent predictors of long (>â90 min) operations. The resulting model was converted to a risk score, which was subsequently validated on second cohort of patients using ROC curves.
Results: After exclusions, data were available for 7227 patients in the derivation (CholeS) cohort. The median operative duration was 60 min (interquartile range 45â85), with 17.7% of operations lasting longer than 90 min. Ten factors were found to be significant independent predictors of operative durations >â90 min, including ASA, age, previous surgical admissions, BMI, gallbladder wall thickness and CBD diameter. A risk score was then produced from these factors, and applied to a cohort of 2405 patients from a tertiary centre for external validation. This returned an area under the ROC curve of 0.708 (SEâ=â0.013, pââ90 min increasing more than eightfold from 5.1 to 41.8% in the extremes of the score.
Conclusion: The scoring tool produced in this study was found to be significantly predictive of long operative durations on validation in an external cohort. As such, the tool may have the potential to enable organisations to better organise theatre lists and deliver greater efficiencies in care
Etude par génomique fonctionnelle de trois gÚnes surexprimés dans les lymphocytes B au cours du lupus érythémateux systémique
Le Lupus Erythémateux Systémique (LES) est une maladie autoimmune sévÚre dont laquelle les lymphocytes B (LB) jouent un rÎle central. Afin de rechercher des anomalies génétiques propre à ces cellules, notre laboratoire a étudié l expression des gÚnes dans les LB de patients atteints d un LES, par rapport à des sujets témoins. Ce projet a pour but d étudier un de ces gÚnes (FKBP11), surexprimé dans les LB au cours du LES. Pour cela nous avons créé, à l aide de lentivirus, des souris transgéniques reproduisant de maniÚre ubiquitaire la surexpression de ce gÚne. Ces souris développent une hyperplasie des organes lymphoïdes, une hyper gamma globulinémie de type IgG3, et présentent une réponse humorale augmentée aprÚs immunisation avec un antigÚne T-indépendant. Notre étude met en évidence que la surexpression de FKBP11 favorise le développement des plasmocytes dans leur phase initiale dépendante de l expression de Pax5, aprÚs induction de la différenciation plasmocytaire in vitro. Enfin, les souris développent des autoanticorps variés. De plus, le rÎle d une surexpression de FKBP11 dans la rupture de tolérance B a été montré chez des souris transgéniques anti-ADN 56R, croisées avec notre modÚle lentigénique, qui voient leur production d autoanticorps augmentée. La surexpression de FKBP11 dans le modÚle C57BL/6lpr/lpr accentue le caractÚre lymphoprolifératif et l hyper gamma globulinémie présents dans ces souris. Au cours de ce projet de thÚse, j ai également initié l étude de deux autres gÚnes surexprimés dans les LB de patients lupiques (PRDX4, TRIB1), par le développement de modÚles transgéniques murins.Systemic Lupus Erythematosus (SLE) is a severe autoimmune disease where B cells play a central role and carry intrinsic genetic abnormalities.Today, only a few SLE genes have been validated in humans. Looking for these intrinsic B cell abnormalities in SLE, we have performed a microarray analysis of the human transcriptoma in B cells from quiescent SLE patients, in comparison to normal subjects. The project proposes to explore the consequences of overexpression of one of these genes: FKBP11. For this purpose, a lentiviral construct allowing the ubiquitous overexpression of FKBP11 was produced, and has been used to generate lentigenic mice. These mice develop a hyperplasia of lymphoid organs, an IgG3 hypergammaglobulinemia and an increase of humoral immune response after immunisation with a T-independent antigen. Our study points out that the overexpression of FKBP11 promotes the plasmocyte development, at the initial stage which is dependent on Pax5 expression, after in vitro induction of the plasmacytic differentiation. Finally, these mice produce various autoantibodies. The role of FKBP11 overexpression in B cell central tolerance breakdown has been demonstrated in anti-DNA 56R transgenic mice crossed with our lentigenic model. These mice have an increase of autoantibody production. The FKBP11 overexpression in C57BL/6lpr/lpr model increases the lymphoproliferative syndrome and the hypergammaglobulinemia in this model. During this thesis, I have also initiated the study of two others genes which were found overexpressed in B cells of lupus patients (PRDX4, TRIB1), by the development of transgenic murine models.STRASBOURG-Bib.electronique 063 (674829902) / SudocSudocFranceF
Hétérogénéité des mécanismes physiopathologiques du syndrome des anti-phospholipides
Le syndrome des antiphospholipides est dĂ©fini par l association d un Ă©vĂ©nement clinique (avortements rĂ©pĂ©tĂ©s et/ou morts fĆtales in utero et/ou thromboses vasculaires) associĂ© Ă un Ă©vĂ©nement biologique, la prĂ©sence d un anticorps antiphospholipide (anticardiolipides et/ou antib2GPI et/ou anticoagulant circulant). En rĂ©alitĂ©, cette dĂ©finition souligne dĂ©jĂ l hĂ©tĂ©rogĂ©nĂ©itĂ© clinique et biologique de ce syndrome et interroge le ou les mĂ©canismes pathogĂ©niques impliquĂ©s. Compte tenu des manifestations thrombotiques observĂ©es au cours de la maladie, on a avancĂ© qu il y existe un mĂ©canisme thrombophilique univoque. Dans les manifestations obstĂ©tricales, la destruction du bouclier d annexine V crĂ©erait les conditions pro-thrombotiques dans le placenta. Plus rĂ©cemment, l Ă©tude d un modĂšle murin est venu souligner l importance du complĂ©ment et en particulier des anaphylatoxines C3 et C5, faisant ainsi du syndrome des antiphospholipides, obstĂ©trical et peut ĂȘtre vasculaire, une maladie inflammatoire, ce qui suggĂšre un mĂ©canisme radicalement diffĂ©rent. Le prĂ©sent travail participe Ă l Ă©lucidation de certains des mĂ©canismes mis en jeu dans le syndrome des antiphospholipides obstĂ©trical grĂące Ă l usage d un modĂšle murin faisant appel au transfert passif d anticorps monoclonaux. Il a pu voir le jour grĂące Ă un important travail prĂ©alable conduit au laboratoire. En utilisant une technique de tri sĂ©lectif sur vĂ©sicules phospholipidiques par cytomĂ©trie en flux, les Lymphocytes B anti phospholipides ont Ă©tĂ© isolĂ©s. Les rĂ©gions variables de ces lymphocytes ont Ă©tĂ© clonĂ©es dans des Baculovirus et les anticorps monoclonaux ont ainsi pu ĂȘtre produits dans des cellules d insectes, et leur spĂ©cificitĂ© fine Ă©tudiĂ©e.Cent microgrammes d anticorps monoclonaux ont Ă©tĂ© injectĂ©s par voie intraveineuse Ă des souris gestantes balb/c Ă J0 et J1 suivant l accouplement des souris. Ces derniĂšres ont Ă©tĂ© sacrifiĂ©es Ă J10 et les structures embryonnaires et placentaires Ă©tudiĂ©es (nombre de rĂ©sorptions fĆtales, histologie conventionnelle et immunofluorescence). L effet de ces anticorps a Ă©galement Ă©tĂ© Ă©tudiĂ© chez des souris invalidĂ©es pour les rĂ©cepteurs activateurs Fcgamma RI et RIII au fragment Fc des immunoglobulines G. L effet de diffĂ©rents anticoagulants (hĂ©parines de bas poids molĂ©culaire, hirudine et fondaparinux) a Ă©galement Ă©tĂ© Ă©valuĂ©. Sur le plan histologique, des souris traitĂ©es selon le protocole dĂ©crit ont Ă©galement Ă©tĂ© Ă©tudiĂ©es vers J5 et l on a pratiquĂ© des Ă©tudes d immunofluorescence indirecte sur des coupes d utĂ©rus gravides. L effet de l antiphospholipide pathologique sur la coagulation a Ă©tĂ© Ă©tudiĂ© en utilisant une Ă©preuve fonctionnelle de gĂ©nĂ©ration de thrombine. En collaboration avec l Ă©quipe d Alain Brisson (Bordeaux), nous avons Ă©valuĂ© l effet de l anticorps pathogĂšne sur le rĂ©seau d annexine V par microscopie Ă force atomique.L injection de diffĂ©rents anticorps monoclonaux produits Ă partir d une seule patiente Ă des souris gestantes entraĂźne des effets variables: seul l anticorps CIC15 parmi ceux qui ont Ă©tĂ© injectĂ©s dĂ©clenche environ 30% de rĂ©sorptions fĆtales. Cet anticorps prĂ©sente des mutations siĂ©geant dans la troisiĂšme rĂ©gion dĂ©terminant la complĂ©mentaritĂ©, et qui sont responsables de la pathogĂ©nicitĂ©. En effet, la configuration germinale de l anticorps obtenue par mutagenĂšse dirigĂ©e a Ă©tĂ© Ă©prouvĂ©e et n exerce pas d effet pathogĂšne dans notre modĂšle. La chronologie d injection est primordiale puisque l injection tardive ne perturbe pas la gestation alors que l injection prĂ©coce est pathogĂšne; cette observation expĂ©rimentale rapproche ce modĂšle des observations humaines d avortements rĂ©pĂ©tĂ©s plutĂŽt que de morts fĆtales in utero faites en clinique humaine. Bien qu il ne soit pas possible de repĂ©rer prĂ©cisĂ©ment la cible de l anticorps directement responsable de la pathogĂ©nicitĂ©, en raison de sa polyrĂ©activitĂ© qui empĂȘche l analyse fine des expĂ©riences d immunofluorescence, CIC15 se dĂ©pose dans le placenta et entraĂźne localement la formation de thrombose. In vitro, CIC15 est d ailleurs capable d accĂ©lĂ©rer la gĂ©nĂ©ration de thrombine mais n a pas d effet sur l organisation du rĂ©seau d annexine V. L effet pathogĂšne s exerce indĂ©pendamment des rĂ©cepteurs activateurs Fcgamma RI RIII. DiffĂ©rents anticoagulants sont capables d abolir les effets pathogĂšnes de CIC15. Cette observation et l absence d infiltrat neutrophilique dans les diffĂ©rentes analyses histologiques constituent un faisceau d arguments lourds en dĂ©faveur de l intervention du complĂ©ment mĂȘme si les souris dĂ©ficientes pour le rĂ©cepteur du C5a n ont pu ĂȘtre utilisĂ©es. En effet, certaines souches de souris (nous avons Ă©prouvĂ© notre anticorps pathogĂšne sur des souris C57bl/6) dont celle qui est invalidĂ©e pour le rĂ©cepteur du C5a, sont rĂ©sistantes Ă CIC15, et ce constat souligne l importance du fond gĂ©nĂ©tique dans la survenue du syndrome expĂ©rimental des antiphospholipides par transfert passif murin.Notre modĂšle est donc un modĂšle obstĂ©trical fondĂ© sur la thrombose intra placentaire par accĂ©lĂ©ration de la gĂ©nĂ©ration de thrombine en prĂ©sence de CIC15. Le mĂ©canisme exact du phĂ©nomĂšne reste inconnu mais nos rĂ©sultats indiquent qu il n y a pas de rĂ©action inflammatoire dans ce systĂšme expĂ©rimental.Ces rĂ©sultats accentuent l hĂ©tĂ©rogĂ©nĂ©itĂ© de la physiopathologie du syndrome des antiphospholipides. Toutefois, et mĂȘme si les modĂšles murins restent un outil trĂšs performant, il est important de pouvoir dĂ©montrer l existence de ces mĂ©canismes chez l homme, ce qui relĂšve, actuellement, de la gageure, en particulier parce que les mĂ©canismes sont multiples.Cette hĂ©tĂ©rogĂ©nĂ©itĂ© physiopathologique pourrait rendre compte au moins en partie des diffĂ©rents phĂ©notypes du syndrome des antiphospholipides observĂ©s (vasculaire versus obstĂ©trical, prĂ©coce versus tardif, veineux versus artĂ©riel, anticardiolipides versus anticoagulants circulants, etc.). Identifier les diffĂ©rents mĂ©canismes est d importance pour deux raisons: (a) permettre de mieux prĂ©dire ainsi le risque individuel et (b) mieux cibler les traitements et les rendre mieux tolĂ©rĂ©s que ne l est l anticoagulation utilisĂ©es actuellement.The anti-phospholipid syndrome associates a clinical event (repeated abortions and/or foetal deaths in utero and/or vascular thrombosis) and a biological event, the presence of (an) anti-phospholipid antibody(ies) (anti-cardiolipid and/or antib-2GPI and/or circulating anticoagulant). This definition underlines the clinical and biological heterogeneity of the syndrome and the potential complexity of the pathogenic mechanisms. Single anti-phospholipid B cells from patient's peripheral blood were sorted by flow cytometry using cardiolipin-labeled vesicles. Messenger RNAs of these single B cells were subjected to reverse transcriptase-polymerase chain reaction to amplify the V region genes of the H and L chains. The amplification products were cloned into recombinant Baculovirus to produce monoclonal human anti-phospholipid antibodies. In the present work, we studied the passive transfer of monoclonal anti-phospholipid antibodies to pregnant mice. Injection of various monoclonal antibodies produced from B cells arising from a randomly selected patient shows that only monoclonal antibody CIC15, among those which were injected, leads to a resorption rate of 30%. This antibody recognizes the cardiolipin and is dependent on annexin A5; it presents three somatic mutations in the first complementary determining region of the light chain [CDR]. Germinal configuration of antibody CIC15 [GL] is poly-reactive, recognizes cardiolipin less strongly and is independent of annexin A5. In our model, GL does not exert any pathogenic effect. These results demonstrate that fine specificity and pathogenic potential of CIC15 is due to the presence of three mutations in CDR, suggesting that it appeared after antigen driven maturation. Chronology of injection is quite important since late injection does not disturb gestation whereas the early injection induces pathological phneomena. Although it is not possible to precisely identify target of CIC15 directly involved in the pathogenicity, because of its poly-reactivity, CIC15 forms deposits in the placenta and involves the formation of local thrombosis. In vitro, CIC15 is able to accelerate the generation of thrombin but does not have any effect on organization of annexin V network. The pathogenic effect is exerted independently of activators Fcgamma RI-RIII receptors. Various anticoagulants are able to abolish the pathogenic effects of CIC15. This observation and the absence of neutrophil infiltrate, as confirmed by various histological analyses, constitute a strong arguments against the activation of complement in this model. Several mice strains (we tested CIC15 on C57/bl6 mice and several deficient mice on C57/bl6 background) are resistant to this antibody, and this result underlines the importance of the genetic background in anti-phospholipid syndrome.Our model is thus an obstetric model relying on placental thrombosis by acceleration of thrombin generation in the presence of CIC15. The exact mechanism remains unknown but our results indicate that there are no inflammatory reaction nor annexin V shield destruction in this experimental system. These results accentuate the heterogeneity of the physiopathology of anti-phospholipid syndrome. Such a physiopathological heterogeneity could at least partially explain the various phenotypes associated to anti-phospholipid syndrome (vascular versus obstetric, early versus late, venous versus arterial, anti-cardiolipid versus lupus anticoagulant, etc).To identify the various mechanisms involved is of importance for two reasons: (a) to make it possible to better predict the individual risk (b) and thus to better target the treatments and render them more tolerated than the currently used classical anti-coagulation administration.STRASBOURG-Sc. et Techniques (674822102) / SudocSudocFranceF
Etude prospective de 51 cas d'uvéites intermédiaires (diagnostics associés, évolution et complications.)
STRASBOURG-Medecine (674822101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF
CONTRIBUTION A L'ETUDE DE LA TOLERANCE LYMPHOCYTAIRE B A L'AIDE DE MODELES TRANSGENIQUES
STRASBOURG-Sc. et Techniques (674822102) / SudocSudocFranceF
Molecular analysis of T-cell receptor V beta chains of human T-cell chronic lymphocytic leukemia does not show intraclonal variability: implications for immunotherapy
Human T-cell chronic lymphocytic leukemia (T-cell CLL) is a heterogeneous disease characterized by a monoclonal malignant proliferation of T cells in which the T-cell receptors (TCRs) can be, when expressed, considered to be membrane tumor-specific antigens. Owing to the increasing number of available monoclonal antihuman TCR reagents, it could be of interest to evaluate the feasibility of anti-TCR treatment during T-cell CLL. To test the therapeutic potentiality of anti-TCR monoclonal antibodies, we first analyzed the intraclonal variability in two terminally ill patients suffering from TCR alpha beta-positive cell CLL bearing different immunophenotypes. The cDNA corresponding to the variable regions of the TCR beta chains originating from the malignant T cells were amplified, cloned into M13 phages, and sequenced. The sequence analysis of multiple independent clones showed no intraclonal variability, with no evidence for ongoing hypermutation in the V beta region genes. The relevance of these findings with regard to an anti-V beta therapy and the comparison with similar analysis during B-cell monoclonal lymphoproliferations are discussed
T-cell receptor Vbeta gene usage in CSF lymphocytes in X-linked adrenoleukodystrophy
X-linked adrenoleukodystrophy (ALD) is a peroxisomal disorder with impaired very-long-chain fatty acid (VLCFA) metabolism that produces a neurological disease with significant variability of clinical phenotypes even within kindred. The two most common forms are the cerebral form (CALD) with an important inflammatory reaction at the active edge of demyelinating lesions, resembling some aspects of multiple sclerosis pathology, and adrenomyeloneuropathy (AMN), which involves the spinal cord and in which the inflammatory reaction is mild or absent. One hypothesis is that the phenotypic variability is related to T cell-mediated immune mechanisms playing a primary role in the demyelinating pathogenic process of CALD. The present study aims to test the hypothesis that CSF of patients with the CALD form contains highly restricted T cell populations. The variable regions of the T cell receptor beta chains (TCR Vbeta) were studied in CSF from 29 ALD patients with different phenotypes. RNA was extracted and cDNA synthesized from CSF lymphocytes; TCR Vbeta gene segments were amplified from the cDNA by polymerase chain reaction (PCR) using 20 family-specific primers. PCR products were analyzed by Southern blot. Some amplified Vbeta products were sequenced. The majority of ALD patients (21/29), whatever their phenotype, exhibited oligoclonal T cell expansion. However the overexpression of some TCR Vbeta families was heterogeneous among the different patients without any preponderance of specific Vbeta families or any clustering according to clinical phenotype. In particular a dominant TCR Vbeta utilization was not found in patients with CALD
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