33 research outputs found

    Involvement of circulating CEA in liver metastases from colorectal cancers re-examined in a new experimental model

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    Both experimental and clinical data show evidence of a correlation between elevated blood levels of carcinoembryonic antigen (CEA) and the development of liver metastases from colorectal carcinomas. However, a cause-effect relationship between these two observations has not been demonstrated. For this reason, we developed a new experimental model to evaluate the possible role of circulating CEA in the facilitation of liver metastases. A CEA-negative subclone from the human colon carcinoma cell line CO115 was transfected either with CEA-cDNA truncated at its 3' end by the deletion of 78 base pairs leading to the synthesis of a secreted form of CEA or with a full-length CEA-cDNA leading to the synthesis of the entire CEA molecule linked to the cell surface by a GPI anchor. Transfectants were selected either for their high CEA secretion (clone CO115-2C2 secreting up to 13 microg CEA per 10(6) cells within 72 h) or for their high CEA membrane expression (clone CO115-5F12 expressing up to 1 x 10(6) CEA molecules per cell). When grafted subcutaneously, CO115-2C2 cells gave rise to circulating CEA levels that were directly related to the tumour volume (from 100 to 1000 ng ml(-1) for tumours ranging from 100 to 1000 mm3), whereas no circulating CEA was detectable in CO115 and CO115-5F12 tumour-bearing mice. Three series of nude mice bearing a subcutaneous xenograft from either clone CO115-2C2 or the CO115-5F12 transfectant, or an untransfected CO115 xenograft, were further challenged for induction of experimental liver metastases by intrasplenic injection of three different CEA-expressing human colorectal carcinoma cell lines (LoVo, LS174T or CO112). The number and size of the liver metastases were shown to be independent of the circulating CEA levels induced by the subcutaneous CEA secreting clone (CO115-2C2), but they were directly related to the metastatic properties of the intrasplenically injected tumour cells

    Characteristics and Outcomes of Patients With Cerebral Venous Sinus Thrombosis in SARS-CoV-2 Vaccine–Induced Immune Thrombotic Thrombocytopenia

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    Importance: Thrombosis with thrombocytopenia syndrome (TTS) has been reported after vaccination with the SARS-CoV-2 vaccines ChAdOx1 nCov-19 (Oxford-AstraZeneca) and Ad26.COV2.S (Janssen/Johnson & Johnson). Objective: To describe the clinical characteristics and outcome of patients with cerebral venous sinus thrombosis (CVST) after SARS-CoV-2 vaccination with and without TTS. Design, setting, and participants: This cohort study used data from an international registry of consecutive patients with CVST within 28 days of SARS-CoV-2 vaccination included between March 29 and June 18, 2021, from 81 hospitals in 19 countries. For reference, data from patients with CVST between 2015 and 2018 were derived from an existing international registry. Clinical characteristics and mortality rate were described for adults with (1) CVST in the setting of SARS-CoV-2 vaccine-induced immune thrombotic thrombocytopenia, (2) CVST after SARS-CoV-2 vaccination not fulling criteria for TTS, and (3) CVST unrelated to SARS-CoV-2 vaccination. Exposures: Patients were classified as having TTS if they had new-onset thrombocytopenia without recent exposure to heparin, in accordance with the Brighton Collaboration interim criteria. Main outcomes and measures: Clinical characteristics and mortality rate. Results: Of 116 patients with postvaccination CVST, 78 (67.2%) had TTS, of whom 76 had been vaccinated with ChAdOx1 nCov-19; 38 (32.8%) had no indication of TTS. The control group included 207 patients with CVST before the COVID-19 pandemic. A total of 63 of 78 (81%), 30 of 38 (79%), and 145 of 207 (70.0%) patients, respectively, were female, and the mean (SD) age was 45 (14), 55 (20), and 42 (16) years, respectively. Concomitant thromboembolism occurred in 25 of 70 patients (36%) in the TTS group, 2 of 35 (6%) in the no TTS group, and 10 of 206 (4.9%) in the control group, and in-hospital mortality rates were 47% (36 of 76; 95% CI, 37-58), 5% (2 of 37; 95% CI, 1-18), and 3.9% (8 of 207; 95% CI, 2.0-7.4), respectively. The mortality rate was 61% (14 of 23) among patients in the TTS group diagnosed before the condition garnered attention in the scientific community and 42% (22 of 53) among patients diagnosed later. Conclusions and relevance: In this cohort study of patients with CVST, a distinct clinical profile and high mortality rate was observed in patients meeting criteria for TTS after SARS-CoV-2 vaccination.info:eu-repo/semantics/publishedVersio

    A novel approach for seismoelectric measurements using multielectrode arrangements - II: laboratory measurements

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    ACLInternational audienceTransient electrokinetic effects may generate conversions between seismic and electromagnetic energy in fluid-filled poroelastic media. Two resulting seismoelectric signals have been predicted and identified: on the one hand electric fields accompanying seismic waves and on the other hand electromagnetic disturbances generated when seismic waves are crossing interfaces. The coseismic electrical field is in general the dominant effect, but it only provides local information around the electrical receivers. On the contrary, the seismoelectric interface response could be exploited in a new high-resolution imaging technique, as it is particularly sensitive to fluid contrasts. However, the detection of such events is a challenging task, mainly because it is usually masked by the higher amplitude coseismic electric field and by the presence of strong electrical noise. In order to increase the signal-to-noise ratio of the interface response, we experimentally study the sensitivity of seismoelectric signals to various electrode arrangements used for their recording. For that, we use a filter theory approach to investigate the response of electrode arrays to measure seismoelectric signals. Then, we confront this approach with seismoelectric data acquired in homogeneous silica glass-beads in laboratory experiments. The measured laboratory coseismic signals were also successfully compared with numerical simulations, which in turn have been used to predict the sensitivity of the interface electromagnetic signals to the data acquisition configuration. This study demonstrates the possibilities offered by multielectrode arrays to enhance the electromagnetic interface response

    4D GIS for Monitoring River Bank Erosion at Meander Bend Scale: Case of Moselle River

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    International audienceThe "Wild Moselle" regional nature reserve extends over 13 km at the western foothills of the Vosges Mountains (France). The hydrological regime of the river is characterized by high flow in winter and spring and low flow in summer. Its average slope is 0.12 % and its average bankfull width is 60 m. The coarse sediment load comes mainly from bank erosion. Although this sector is relatively less affected by past or present human activities, the propagation of morphodynamic adjustments initiated by actions carried out both upstream and downstream of this sector impacts the current functioning of the river. These erosion waves converge today towards the central part of the reserve, which led to the collapse of the central pier of the Bainville-aux-Miroirs bridge during a 2-year flood in 2011, and could induce potential risks of defluviation which may destabilize infrastructures. In this context, the study carried out aims to characterize and anticipate the morphodynamic evolutions of the Moselle to be able to propose scenarios of management and restoration of the lateral mobility of the river. For this purpose, a 2D hydro-sedimentary model is being built over the entire reserve, combined with a detailed morpho-sedimentary monitoring. In order to improve the understanding of the lateral migration of the Moselle River, a photogrammetric monitoring was carried out along the concave bank of the most active meander of the studied sector. To follow this morphological evolution more closely, it was decided to establish a 4D GIS. The objective of this monitoring is to compare the rate of bank retreat with hydrodynamic parameters in order to estimate the geotechnical properties of the bank. Comparison of the observed and modelled bank retreat must thus allow these different parameters to be calibrated in the hydro-sedimentary model. As part of this work, this paper aims to highlight the use of 4D GIS to monitor bank retreat at the scale of a meander bend and is divided into three different parts: (i) a state of art to situate the study into the current knowledge and technologies, (ii) a presentation of the study area and the measurements carried out and (iii) a description of the different 3D or 4D data produced and the consequent spatial analyses

    DĂ©tection d'une poche d'eau au glacier de TĂȘte Rousse : mesures prĂ©ventives pour Ă©viter une catastrophe

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    National audienceEntre 2009 et 2010, une poche d'eau d'un volume d'environ 65000 m3 a Ă©tĂ© dĂ©tectĂ©e dans le glacier de TĂȘte Rousse grĂące Ă  une combinaison de mĂ©thodes gĂ©ophysiques mises en oeuvre conjointement par trois laboratoires grenoblois (LGGE, ISTerre-ex LGIT et LTHE). C'est la premiĂšre fois qu'une poche d'eau intra-glaciaire de cette importance est ainsi dĂ©tectĂ©e avant une rupture. Cette poche reprĂ©sentait une menace pour St Gervais, avec un volume Ă  peu prĂšs Ă©quivalent Ă  celui qui avait provoquĂ© la catastrophe de 1892 (175 morts). Trois mille personnes Ă©taient potentiellement menacĂ©es en 2010. Nous avons alors alertĂ© les autoritĂ©s publiques le 13 juillet 2010 et prĂ©conisĂ© la vidange artificielle de cette poche d'eau. Des dĂ©cisions immĂ©diates ont conduit Ă  des opĂ©rations de pompage entre aoĂ»t et octobre 2010. Nous prĂ©sentons ici les mĂ©thodes gĂ©ophysiques qui ont permis de dĂ©tecter cette poche ainsi que l'analyse de l'alĂ©a d'une vidange brutale. Enfin, nous analysons le rĂ©gime thermique du glacier qui constitue la cause de la rĂ©tention de l'eau sous glaciaire
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