316 research outputs found

    Retour à la maison des Nymphes de Néapolis

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    On connaît aujourd’hui de nombreux ensembles décoratifs de l’Occident romain appartenant aux dernières décennies du IVe ou aux premières du Ve siècle, où toutes les références symboliques et culturelles se rapportent à des référents classiques, sans aucune trace de références chrétiennes. On peut citer les exemples africains de Sidi Ghrib ou de la maison aux Chevaux de Carthage, le fameux cas sicilien de la Villa du Casale à Piazza Armerina ou, en Espagne, ceux de la Villa de Carranque ou de Baños de Valdearados. Pour prendre des exemples lusitaniens, on peut penser à la maison des Sept Sages de Mérida, ou encore au fascinant complexe de Milreu. La maison des Nymphes de Nabeul est un cas d’école dans ce domaine.Fundação para a Ciência e a Tecnologia (FCT), Fundação Calouste Gulbenkian, Fundação Millennium bcp, Direcção Geral do Livro e das Bibliotecas/M

    Aminopeptidase B, a glucagon-processing enzyme: site directed mutagenesis of the Zn2+-binding motif and molecular modelling

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    <p>Abstract</p> <p>Background</p> <p>Aminopeptidase B (Ap-B; EC 3.4.11.6) catalyzes the cleavage of basic residues at the N-terminus of peptides and processes glucagon into miniglucagon. The enzyme exhibits, <it>in vitro</it>, a residual ability to hydrolyze leukotriene A<sub>4 </sub>into the pro-inflammatory lipid mediator leukotriene B<sub>4</sub>. The potential bi-functional nature of Ap-B is supported by close structural relationships with LTA<sub>4 </sub>hydrolase (LTA<sub>4</sub>H ; EC 3.3.2.6). A structure-function analysis is necessary for the detailed understanding of the enzymatic mechanisms of Ap-B and to design inhibitors, which could be used to determine the complete <it>in vivo </it>functions of the enzyme.</p> <p>Results</p> <p>The rat Ap-B cDNA was expressed in <it>E. coli </it>and the purified recombinant enzyme was characterized. 18 mutants of the H<sup>325</sup>EXXHX<sub>18</sub>E<sup>348 </sup>Zn<sup>2+</sup>-binding motif were constructed and expressed. All mutations were found to abolish the aminopeptidase activity. A multiple alignment of 500 sequences of the M1 family of aminopeptidases was performed to identify 3 sub-families of exopeptidases and to build a structural model of Ap-B using the x-ray structure of LTA<sub>4</sub>H as a template. Although the 3D structures of the two enzymes resemble each other, they differ in certain details. The role that a loop, delimiting the active center of Ap-B, plays in discriminating basic substrates, as well as the function of consensus motifs, such as RNP1 and Armadillo domain are discussed. Examination of electrostatic potentials and hydrophobic patches revealed important differences between Ap-B and LTA<sub>4</sub>H and suggests that Ap-B is involved in protein-protein interactions.</p> <p>Conclusion</p> <p>Alignment of the primary structures of the M1 family members clearly demonstrates the existence of different sub-families and highlights crucial residues in the enzymatic activity of the whole family. <it>E. coli </it>recombinant enzyme and Ap-B structural model constitute powerful tools for investigating the importance and possible roles of these conserved residues in Ap-B, LTA<sub>4</sub>H and M1 aminopeptidase catalytic sites and to gain new insight into their physiological functions. Analysis of Ap-B structural model indicates that several interactions between Ap-B and proteins can occur and suggests that endopeptidases might form a complex with Ap-B during hormone processing.</p

    Increased mortality in hematological malignancy patients with acute respiratory failure from undetermined etiology : a Groupe de Recherche en Réanimation Respiratoire en Onco-Hématologique (Grrr-OH) study

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    Background: Acute respiratory failure (ARF) is the most frequent complication in patients with hematological malignancies and is associated with high morbidity and mortality. ARF etiologies are numerous, and despite extensive diagnostic workflow, some patients remain with undetermined ARF etiology. Methods: This is a post-hoc study of a prospective multicenter cohort performed on 1011 critically ill hematological patients. Relationship between ARF etiology and hospital mortality was assessed using a multivariable regression model adjusting for confounders. Results: This study included 604 patients with ARF. All patients underwent noninvasive diagnostic tests, and a bronchoscopy and bronchoalveolar lavage (BAL) was performed in 155 (25.6%). Definite diagnoses were classified into four exclusive etiological categories: pneumonia (44.4%), non-infectious diagnoses (32.6%), opportunistic infection (10.1%) and undetermined (12.9%), with corresponding hospital mortality rates of 40, 35, 55 and 59%, respectively. Overall hospital mortality was 42%. By multivariable analysis, factors associated with hospital mortality were invasive pulmonary aspergillosis (OR 7.57 (95% CI 3.06-21.62); p 7 (OR 3.32 (95% CI 2.15-5.15); p < 0.005) and an undetermined ARF etiology (OR 2.92 (95% CI 1.71-5.07); p < 0.005). Conclusions: In patients with hematological malignancies and ARF, up to 13% remain with undetermined ARF etiology despite comprehensive diagnostic workup. Undetermined ARF etiology is independently associated with hospital mortality. Studies to guide second-line diagnostic strategies are warranted

    Determinants of 1-year survival in critically ill acute leukemia patients : a GRRR-OH study

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    Acute leukemia (AL) is the most common hematological malignancy requiring intensive care unit (ICU) management. Data on long-term survival are limited. This is a post hoc analysis of the prospective multicenter data from France and Belgium: A Groupe de Recherche Respiratoire en Reanimation Onco-Hematologique [A Research Group on Acute Respiratory Failure in Onco-Hematological Patients (French)] Study, to identify determinants of 1-year survival in critically ill AL patients. A total of 278 patients were admitted in the 17 participating ICUs. Median age was 58 years and 70% had newly diagnosed leukemia. ICU mortality rate was 28.6 and 39.6% of the patients alive at 1 year. Admission for intensive monitoring was independently associated with better 1-year survival by multivariate analysis. Conversely, relapsed/refractory disease, secondary leukemia, mechanical ventilation and renal replacement therapy were independently associated with 1-year mortality. This study confirms the impact of organ dysfunction on long-term survival in ICU patients with AL. Follow-up studies to assess respiratory and renal recovery are warranted

    The FOXO1 Transcription Factor Instructs the Germinal Center Dark Zone Program

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    SummaryThe pathways regulating formation of the germinal center (GC) dark zone (DZ) and light zone (LZ) are unknown. In this study we show that FOXO1 transcription factor expression was restricted to the GC DZ and was required for DZ formation, since its absence in mice led to the loss of DZ gene programs and the formation of LZ-only GCs. FOXO1-negative GC B cells displayed normal somatic hypermutation but defective affinity maturation and class switch recombination. The function of FOXO1 in sustaining the DZ program involved the trans-activation of the chemokine receptor CXCR4, and cooperation with the BCL6 transcription factor in the trans-repression of genes involved in immune activation, DNA repair, and plasma cell differentiation. These results also have implications for the role of FOXO1 in lymphomagenesis because they suggest that constitutive FOXO1 activity might be required for the oncogenic activity of deregulated BCL6 expression

    Migrant health in French Guiana: Are undocumented immigrants more vulnerable?

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    <p>Abstract</p> <p>Background</p> <p>Few data exist on the health status of the immigrant population in French Guiana. The main objective of this article was to identify differences in its health status in relation to that of the native-born population.</p> <p>Methods</p> <p>A representative, population-based, cross-sectional survey was conducted in 2009 among 1027 adults living in Cayenne and St-Laurent du Maroni. Health status was assessed in terms of self-perceived health, chronic diseases and functional limitations. The migration variables were immigration status, the duration of residence in French Guiana and the country of birth. Logistic regression models were conducted.</p> <p>Results</p> <p>Immigrants account for 40.5% and 57.8% of the adult population of Cayenne and St-Laurent du Maroni, respectively. Most of them (60.7% and 77.5%, respectively) had been living in French Guiana for more than 10 years. A large proportion were still undocumented or had a precarious legal status. The undocumented immigrants reported the worst health status (OR = 3.18 [1.21-7.84] for self-perceived health, OR = 2.79 [1.22-6.34] for a chronic disease, and OR = 2.17 [1.00-4.70] for a functional limitation). These differences are partially explained by socioeconomic status and psychosocial factors. The country of birth and the duration of residence also had an impact on health indicators.</p> <p>Conclusion</p> <p>Data on immigrant health are scarce in France, and more generally, immigrant health problems have been largely ignored in public health policies. Immigrant health status is of crucial interest to health policy planners, and it is especially relevant in French Guiana, considering the size of the foreign-born population in that region.</p

    Predictors of hospital discharge and mortality in patients with diabetes and COVID-19: updated results from the nationwide CORONADO study

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    AIMS/HYPOTHESIS: This is an update of the results from the previous report of the CORONADO (Coronavirus SARS-CoV-2 and Diabetes Outcomes) study, which aims to describe the outcomes and prognostic factors in patients with diabetes hospitalised for coronavirus disease-2019 (COVID-19). METHODS: The CORONADO initiative is a French nationwide multicentre study of patients with diabetes hospitalised for COVID-19 with a 28-day follow-up. The patients were screened after hospital admission from 10 March to 10 April 2020. We mainly focused on hospital discharge and death within 28 days. RESULTS: We included 2796 participants: 63.7% men, mean age 69.7 ± 13.2 years, median BMI (25th-75th percentile) 28.4 (25.0-32.4) kg/m(2). Microvascular and macrovascular diabetic complications were found in 44.2% and 38.6% of participants, respectively. Within 28 days, 1404 (50.2%; 95% CI 48.3%, 52.1%) were discharged from hospital with a median duration of hospital stay of 9 (5-14) days, while 577 participants died (20.6%; 95% CI 19.2%, 22.2%). In multivariable models, younger age, routine metformin therapy and longer symptom duration on admission were positively associated with discharge. History of microvascular complications, anticoagulant routine therapy, dyspnoea on admission, and higher aspartate aminotransferase, white cell count and C-reactive protein levels were associated with a reduced chance of discharge. Factors associated with death within 28 days mirrored those associated with discharge, and also included routine treatment by insulin and statin as deleterious factors. CONCLUSIONS/INTERPRETATION: In patients with diabetes hospitalised for COVID-19, we established prognostic factors for hospital discharge and death that could help clinicians in this pandemic period. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT04324736
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