Les séries fluvio-éoliennes du "Cutler Group" :: Permien (Utah, USA). Modèle architectural et expression des unités génétiques

National audienceL'essor qu'a connu la stratigraphie séquentielle dans les environnements continentaux a permis de définir des modèles architecturaux pour des séries fluvio-lacustres. Plus récemment, les modèles proposés ont intégré les dépôts éoliens dans les systèmes continentaux côtiers ou lacustres (préservation de l'éolien vs variations de la table d'eau, e.g. Carr-Crabaugh & Kocurek, 1998) ou dans les systèmes continentaux endoréiques (préservation de l'éolien vs climat (e.g. Clemmensen et al., 1998) ou préservation de l'éolien vs accommodation et flux de sédiments, e.g. Bourquin et al., 2009). Cependant, peu de modèles discutent les variations de préservation des dépôts éoliens par rapport aux environnements continentaux associés (fluvial, lac, playa) afin de prédire un modèle architectural des dépôts éoliens (du réservoir au bassin) en fonction du contexte géodynamique. L'objectif de cet exposé est de contraindre l'expression des unités génétiques et de proposer un modèle architectural montrant les variations de préservation des dépôts éoliens en fonction du contexte tectonique, climatique et eustatique. L'étude des séries du Permien inférieur, " Cutler Group ", du " Paradox Basin " (SE Utah), caractérisées par des dépôts fluvio-éoliens (e.g. Condon, 1997), a été réalisée à partir de 5 sections sédimentologiques. Elles sont localisées sur un profil proximal représenté par des dépôts dominés fluvial jusqu'à des dépôts dominés éolien dans le domaine distal (e.g. Mountney & Jagger, 2004). Une étude sédimentologique et stratigraphique détaillée permet de proposer une évolution spatiale et temporelle des environnements de dépôt. Nous avons ainsi mis en évidence (1) les variations d'expression des unités génétiques d'un environnement proximal à un environnement distal en climat semi-aride, (2) plusieurs modèles architecturaux montrant l'évolution verticale depuis un contexte de bassin côtier, à dunes éoliennes faiblement préservées, vers des environnements plus continentaux dominés éolien puis vers des systèmes fluvio-lacustres à faible préservation des dépôts éoliens

Análise faciológica e estraquigrafia de seqüências dos depósitos Sin-Rifte da Formação Barra de Itiúba, Bacia de Sergipe-Alagoas

Este trabalho de doutorado aborda uma análise faciológica e tectono-estratigráfica da Formação Barra de Itiúba (Hauteriviano-Barremiano), unidade fluvio-deltaico-lacustre depositada durante o início do rifteamento da Bacia de Sergipe-Alagoas, localizada na margem norte atlântica do Brasil. A abordagem multidisciplinar (sedimentologia, estratigrafia e tectônica) resultou em um estudo de alta resolução das seqüências deposicionais de 3ª ordem e caracterização da qualidade de reservatórios. Dois poços (A e B) e diversos afloramentos foram estudados em detalhe (granulometria, estruturas sedimentares, conteúdo fóssil, dados de raio-gama, superfícies estratigráficas chaves). O poço A está localizado na Sub-bacia de Sergipe (Campo de Caioba), e o Poço B no nordeste de Alagoas (Campo de Furado), estruturalmente separadas pelo “Alto do Japoatã-Penedo”, onde se localiza os afloramentos. A aplicação de um modelo recente de estratigrafia de seqüências em rifte nos poços (A e B) permitiu a identificação de sete seqüências deposicionais completas de 3ª ordem. Cobrindo a "Discordância pré-Aratu" (DPA)”, as seqüências começam com um trato de lago subpreenchido (Underfilled systems tract), que representa a criação rápida de acomodação ligada a um pulso tectônico de 3ª ordem. A fase seguinte é representada uma longa tendência progradante de uma sucessão deltaica granocrescente ascendente que preenche o espaço de acomodação criado anteriormente (trato de lago preenchido ou “Filled systems tract”). O trato de lago com preenchimento excessivo (Overfilled systems tract) representa o último estágio do preenchimento de cada seqüência de 3ª ordem, geralmente representado por depósitos proximais de canais distributários erosivos e amalgamados associados a depósitos de crevasse splay e de baía interdistributária. Na região dos afloramentos, os depósitos estudados foram principalmente controlados pela falha normal de borda (“Falha de Propriá”). Treze seções estratigráficas foram medidas e analisadas detalhadamente, inclusive direções dos paleocorrentes, resultando na construção de perfis litológicos de escala 1: 100. A descrição de duas seções estratigráficas permitiu a identificação de seqüências estratigráficas de 4ª ordem. A integração entre análise de fácies e paleocorrentes no contexto estrutural, com individualização de grabens, forneceu uma idéia melhor da contribuição axial versus transversal em sistema de rifte. A análise do paleofluxo mostra que, dependendo da área considerada, o aporte sedimentar muda de fontes transversais para axiais. No total, foram descritas 22 litofácies e sete associações de fácies. A caracterização de reservatórios no poço A permitiu a identificação de 11 zonas de reservatórios e 2 não reservatórios, e 12 zonas de reservatórios e um não-reservatório no poço B. As melhores zonas, com propriedades excelentes a muito boas, foram principalmente encontradas em sedimentos de canais distributários depositados durante fases de preenchimento excessivo (Overfilled systems tract). As baixas propriedades de reservatórios (baixa a boa) resultaram principalmente de deformação sin-sedimentar das lâminas argilosas (mud drapes), intensa bioturbação e fluidização que causaram heterogeneidade e alta diminuição da permeabilidade.This thesis deals with a tectonic-stratigraphic analysis of the Barra de Itiúba Formation (Hauterivian-Barremian), a fluvio-deltaico-lacustrine unit deposited during the initial rifting of the Sergipe-Alagoas Basin, located on the north Atlantic coast of Brazil. The multidisciplinary approach (sedimentology, stratigraphy and tectonics) resulted in a high-resolution study of the 3rd-order depositional sequences, and characterization of reservoir quality. Two well cores (A and B) and numerous outcrops were studied in detail (grain size, sedimentary structures, fossil content, gamma-ray data, key stratigraphic surfaces). Well A is located in the Sergipe Sub-basin (Caioba Field) and Well B in northeastern Alagoas (Furado Field), structurally separated by the “Japoatã-Penedo High ", where the outcrops are located. Application of a recent sequence stratigraphic model for rifts to the studied cores (A and B) allowed the identification of seven complete depositional 3rd-order sequences. Overlying the "Pre-Aratu Unconformity" (PAU), the sequences begin with an Underfilled systems tract that represents the rapid accommodation creation linked to a 3rd-order tectonic pulse. The next phase is represented by a long progradational, coarsening-upward deltaic sequence (Filled systems tract) that fills the accommodation space previously created. The Overfilled systems tract is the last filling stage in each 3rd-order sequence, usually represented by proximal deposits of amalgamated distributary channels associated with crevasse splay and interdistributary bay deposits. In the outcrop region, the studied deposits were mainly controlled by the normal border fault ("Propriá Fault"). Thirteen stratigraphic sections were measured and analyzed in detail, including paleocurrent directions, resulting in the construction of lithological profiles at 1: 100 scale. The description of two stratigraphic sections allowed the identification of 4th-order stratigraphic sequences. Integration between facies and paleocurrent analysis in the structural context, with individualization of grabens, provided a better idea of the axial versus transversal contribution in the rift system. Paleoflow analysis showed that, depending on the area considered, the sedimentary input changes from transversal to axial sources. A total of 22 lithofacies and seven facies associations were described. Reservoir characterization in Well A allowed the identification of 11 reservoir zones and 2 non-reservoir zones, and 12 reservoir zones and one non-reservoir in Well B. The best zones, with excellent to very good reservoir properties, were found mainly in distributary channel deposits formed during Overfilled systems tracts. Zones with poor reservoir properties (low to good) resulted mainly from syn-sedimentary deformation of mud drapes, intense bioturbation and fluidization that caused heterogeneity and highly decreased permeability

Análise faciológica e estraquigrafia de seqüências dos depósitos Sin-Rifte da Formação Barra de Itiúba, Bacia de Sergipe-Alagoas

Este trabalho de doutorado aborda uma análise faciológica e tectono-estratigráfica da Formação Barra de Itiúba (Hauteriviano-Barremiano), unidade fluvio-deltaico-lacustre depositada durante o início do rifteamento da Bacia de Sergipe-Alagoas, localizada na margem norte atlântica do Brasil. A abordagem multidisciplinar (sedimentologia, estratigrafia e tectônica) resultou em um estudo de alta resolução das seqüências deposicionais de 3ª ordem e caracterização da qualidade de reservatórios. Dois poços (A e B) e diversos afloramentos foram estudados em detalhe (granulometria, estruturas sedimentares, conteúdo fóssil, dados de raio-gama, superfícies estratigráficas chaves). O poço A está localizado na Sub-bacia de Sergipe (Campo de Caioba), e o Poço B no nordeste de Alagoas (Campo de Furado), estruturalmente separadas pelo “Alto do Japoatã-Penedo”, onde se localiza os afloramentos. A aplicação de um modelo recente de estratigrafia de seqüências em rifte nos poços (A e B) permitiu a identificação de sete seqüências deposicionais completas de 3ª ordem. Cobrindo a "Discordância pré-Aratu" (DPA)”, as seqüências começam com um trato de lago subpreenchido (Underfilled systems tract), que representa a criação rápida de acomodação ligada a um pulso tectônico de 3ª ordem. A fase seguinte é representada uma longa tendência progradante de uma sucessão deltaica granocrescente ascendente que preenche o espaço de acomodação criado anteriormente (trato de lago preenchido ou “Filled systems tract”). O trato de lago com preenchimento excessivo (Overfilled systems tract) representa o último estágio do preenchimento de cada seqüência de 3ª ordem, geralmente representado por depósitos proximais de canais distributários erosivos e amalgamados associados a depósitos de crevasse splay e de baía interdistributária. Na região dos afloramentos, os depósitos estudados foram principalmente controlados pela falha normal de borda (“Falha de Propriá”). Treze seções estratigráficas foram medidas e analisadas detalhadamente, inclusive direções dos paleocorrentes, resultando na construção de perfis litológicos de escala 1: 100. A descrição de duas seções estratigráficas permitiu a identificação de seqüências estratigráficas de 4ª ordem. A integração entre análise de fácies e paleocorrentes no contexto estrutural, com individualização de grabens, forneceu uma idéia melhor da contribuição axial versus transversal em sistema de rifte. A análise do paleofluxo mostra que, dependendo da área considerada, o aporte sedimentar muda de fontes transversais para axiais. No total, foram descritas 22 litofácies e sete associações de fácies. A caracterização de reservatórios no poço A permitiu a identificação de 11 zonas de reservatórios e 2 não reservatórios, e 12 zonas de reservatórios e um não-reservatório no poço B. As melhores zonas, com propriedades excelentes a muito boas, foram principalmente encontradas em sedimentos de canais distributários depositados durante fases de preenchimento excessivo (Overfilled systems tract). As baixas propriedades de reservatórios (baixa a boa) resultaram principalmente de deformação sin-sedimentar das lâminas argilosas (mud drapes), intensa bioturbação e fluidização que causaram heterogeneidade e alta diminuição da permeabilidade.This thesis deals with a tectonic-stratigraphic analysis of the Barra de Itiúba Formation (Hauterivian-Barremian), a fluvio-deltaico-lacustrine unit deposited during the initial rifting of the Sergipe-Alagoas Basin, located on the north Atlantic coast of Brazil. The multidisciplinary approach (sedimentology, stratigraphy and tectonics) resulted in a high-resolution study of the 3rd-order depositional sequences, and characterization of reservoir quality. Two well cores (A and B) and numerous outcrops were studied in detail (grain size, sedimentary structures, fossil content, gamma-ray data, key stratigraphic surfaces). Well A is located in the Sergipe Sub-basin (Caioba Field) and Well B in northeastern Alagoas (Furado Field), structurally separated by the “Japoatã-Penedo High ", where the outcrops are located. Application of a recent sequence stratigraphic model for rifts to the studied cores (A and B) allowed the identification of seven complete depositional 3rd-order sequences. Overlying the "Pre-Aratu Unconformity" (PAU), the sequences begin with an Underfilled systems tract that represents the rapid accommodation creation linked to a 3rd-order tectonic pulse. The next phase is represented by a long progradational, coarsening-upward deltaic sequence (Filled systems tract) that fills the accommodation space previously created. The Overfilled systems tract is the last filling stage in each 3rd-order sequence, usually represented by proximal deposits of amalgamated distributary channels associated with crevasse splay and interdistributary bay deposits. In the outcrop region, the studied deposits were mainly controlled by the normal border fault ("Propriá Fault"). Thirteen stratigraphic sections were measured and analyzed in detail, including paleocurrent directions, resulting in the construction of lithological profiles at 1: 100 scale. The description of two stratigraphic sections allowed the identification of 4th-order stratigraphic sequences. Integration between facies and paleocurrent analysis in the structural context, with individualization of grabens, provided a better idea of the axial versus transversal contribution in the rift system. Paleoflow analysis showed that, depending on the area considered, the sedimentary input changes from transversal to axial sources. A total of 22 lithofacies and seven facies associations were described. Reservoir characterization in Well A allowed the identification of 11 reservoir zones and 2 non-reservoir zones, and 12 reservoir zones and one non-reservoir in Well B. The best zones, with excellent to very good reservoir properties, were found mainly in distributary channel deposits formed during Overfilled systems tracts. Zones with poor reservoir properties (low to good) resulted mainly from syn-sedimentary deformation of mud drapes, intense bioturbation and fluidization that caused heterogeneity and highly decreased permeability

CMV drives the expansion of highly functional memory T cells expressing NK-cell receptors in renal transplant recipients

Cytomegalovirus (CMV) is a common opportunistic infection encountered in renal transplant recipients (RTRs) and may be reactivated without symptoms at any time post-transplant. We describe how active and latent CMV affect T-cell subsets in RTRs who are stable on maintenance therapy. T-cell responses to CMV were assessed in RTRs (n = 54) > 2 years post-transplant, and healthy controls (n = 38). Seven RTRs had CMV DNA detectable in plasma. CMV antibody and DNA aligned with increased proportions of CD8 + T cells and reduced CD4/CD8 ratios. This paralleled an expansion of effector memory T-cell (T EM ), terminally differentiated T-cell (T EMRA ) and CD57 + T EMRA cell populations. Expression of NK-cell receptors, LIR-1 and KLRG1 on CD4 + and CD8 + CD57 + T EM and T EMRA cells correlated with elevated interferon-? and cytotoxic responses to anti-CD3 and increased cytotoxic responses to CMV phosphoprotein (pp) 65 in RTRs who carried CMV DNA. CD8 + T cells from all CMV seropositive RTRs responded efficiently to CMV immediate early (IE) -1 peptides. The data show that latent and active CMV infection can alter T-cell subsets in RTRs many years after transplantation, and up-regulate T-cell expression of NK-cell receptors. This may enhance effector responses of CD4 + and CD8 + T cells against CMV

Risk of Perforated Colonic Diverticulitis in Patients With Chronic Kidney Disease Requiring Sodium Polystyrene Sulfonate

International audienc

Clinical and Prognostic Factors in Patients with IgG4-Related Kidney Disease

International audienceBackground IgG4-related kidney disease is a major manifestation of IgG4-related disease, a systemic fibroinflammatory disorder. However, the clinical and prognostic kidney-related factors in patients with IgG4-related kidney disease are insufficiently defined. Methods We conducted an observational cohort study using data from 35 sites in two European countries. Clinical, biologic, imaging, and histopathologic data; treatment modalities; and outcomes were collected from medical records. Logistic regression was performed to identify the possible factors related to an eGFR ≤30 ml/min per 1.73 m 2 at the last follow-up. Cox proportional hazards model was performed to assess the factors associated with the risk of relapse. Results We studied 101 adult patients with IgG4-related disease with a median follow-up of 24 (11–58) months. Of these, 87 (86%) patients were male, and the median age was 68 (57–76) years. Eighty-three (82%) patients had IgG4-related kidney disease confirmed by kidney biopsy, with all biopsies showing tubulointerstitial involvement and 16 showing glomerular lesions. Ninety (89%) patients were treated with corticosteroids, and 18 (18%) patients received rituximab as first-line therapy. At the last follow-up, the eGFR was below 30 ml/min per 1.73 m 2 in 32% of patients; 34 (34%) patients experienced a relapse, while 12 (13%) patients had died. By Cox survival analysis, the number of organs involved (hazard ratio [HR], 1.26; 95% confidence interval [CI], 1.01 to 1.55) and low C3 and C4 concentrations (HR, 2.31; 95% CI, 1.10 to 4.85) were independently associated with a higher risk of relapse, whereas first-line therapy with rituximab was protective (HR, 0.22; 95% CI, 0.06 to 0.78). At their last follow-up, 19 (19%) patients had an eGFR ≤30 ml/min per 1.73 m 2 . Age (odd ratio [OR], 1.11; 95% CI, 1.03 to 1.20), peak serum creatinine (OR, 2.74; 95% CI, 1.71 to 5.47), and serum IgG4 level ≥5 g/L (OR, 4.46; 95% CI, 1.23 to 19.40) were independently predictive for severe CKD. Conclusions IgG4-related kidney disease predominantly affected middle-aged men and manifested as tubulointerstitial nephritis with potential glomerular involvement. Complement consumption and the number of organs involved were associated with a higher relapse rate, whereas first-line therapy with rituximab was associated with lower relapse rate. Patients with high serum IgG4 concentrations (≥5 g/L) had more severe kidney disease