19 research outputs found

    Neuropilin-1 Signaling through p130Cas Tyrosine Phosphorylation Is Essential for Growth Factor-Dependent Migration of Glioma and Endothelial Cells▿

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    Neuropilin-1 (NRP1) is a receptor for vascular endothelial growth factor (VEGF) and plays an important role in mediating cell motility. However, the NRP1 signaling pathways important for cell motility are poorly understood. Here we report that p130Cas tyrosine phosphorylation is stimulated by hepatocyte growth factor and platelet-derived growth factor in U87MG glioma cells and VEGF in endothelial cells and is dependent on NRP1 via its intracellular domain. In endothelial cells, NRP1 silencing reduced, but did not prevent, VEGF receptor 2 (VEGFR2) phosphorylation, while expression of a mutant form of NRP1 lacking the intracellular domain (NRP1ΔC) did not affect receptor phosphorylation in U87MG cells or human umbilical vein endothelial cells (HUVECs). In HUVECs, NRP1 was also required for VEGF-induced phosphorylation of proline-rich tyrosine kinase 2, which was necessary for p130Cas phosphorylation. Importantly, knockdown of NRP1 or p130Cas or expression of either NRP1ΔC or a non-tyrosine-phosphorylatable substrate domain mutant protein (p130Cas15F) was sufficient to inhibit growth factor-mediated migration of glioma and endothelial cells. These data demonstrate for the first time the importance of the NRP1 intracellular domain in mediating a specific signaling pathway downstream of several receptor tyrosine kinases and identify a critical role for a novel NRP1-p130Cas pathway in the regulation of chemotaxis

    Barriers to publishing in biomedical journals perceived by a sample of French researchers: results of the DIAzePAM study

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    Abstract Background As publishing is essential but competitive for researchers, difficulties in writing and submitting medical articles to biomedical journals are disabling. The DIAzePAM (DifficultĂ©s des Auteurs Ă  la Publication d’Articles MĂ©dicaux) survey aimed to assess the difficulties experienced by researchers in the AP-HP (Assistance Publique – HĂŽpitaux de Paris, i.e., Paris Hospitals Board, France), the largest public health institution in Europe, when preparing articles for biomedical journals. The survey also aimed to assess researchers’ satisfaction and perceived needs. Methods A 39-item electronic questionnaire based on qualitative interviews was addressed by e-mail to all researchers registered in the AP-HP SIGAPS (SystĂšme d’Interrogation, de Gestion et d’Analyse des Publications Scientifiques) bibliometric database. Results Between 28 May and 15 June 2015, 7766 researchers should have received and read the e-mail, and 1191 anonymously completed the questionnaire (<45 years of age: 63%; women: 55%; physician: 81%; with PhD or Habilitation Ă  Diriger des recherches––accreditation to direct research––: 45%). 94% of respondents had published at least one article in the previous 2 years. 76% of respondents felt they were not publishing enough, mainly because of lack of time to write (79%) or submit (27%), limited skills in English (40%) or in writing (32%), and difficulty in starting writing (35%). 87% of respondents would accept technical support, especially in English reediting (79%), critical reediting (63%), formatting (52%), and/or writing (41%), to save time (92%) and increase high-impact-factor journal submission and acceptance (75%). 79% of respondents would appreciate funding support for their future publications, for English reediting (56%), medical writing (21%), or publication (38%) fees. They considered that this funding support could be covered by AP-HP (73%) and/or by the added financial value obtained by their department from previous publications (56%). Conclusions The DIAzePAM survey highlights difficulties experienced by researchers preparing articles for biomedical journals, and details room for improvement

    Impact of the COVID-19 Pandemic on Patients Affected by Non-Communicable Diseases in Europe and in the USA

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    An international online patient community, Carenity, conducted a patient study in two independent waves among adults affected by non-communicable diseases (NCDs) in Europe and in the United States of America (USA). The study aimed to assess the real time impact of the coronavirus disease 2019 (COVID-19) on the medical conditions of patients with NCDs, their access to health care, and their adaptation to daily life as well as to describe their sources of information on COVID-19 and their needs for specific information and support. During the pandemic, 50% of the patients reported a worsening of their medical condition, and 17% developed a new disease. Additionally, 26% of the respondents reported an impact of the pandemic on regular/long-term treatment intake. 54% of the patients felt very or completely socially isolated and reported a strong impact of the COVID-19 pandemic on their stress level and state of mind, with higher levels observed in the USA compared to Europe. 59% of the respondents wished to have received additional information regarding the risks associated to their medical condition during the pandemic. Television was the most used source of information, whereas physicians were the most trusted one. This study describes the substantial impact of the COVID-19 pandemic on NCD patients

    Design of gold nanoparticles for magnetic resonance imaging.

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    International audienceImproving the sensitivity of magnetic resonance imaging (MRI), a powerful non‐invasive medical imaging technique, requires the development of novel contrast agents with a higher efficiency than gadolinium chelates such as DTPA:Gd (DTPA: diethylenetriaminepentaacetic acid) that are currently used for clinical diagnosis. To achieve this objective, the strategy that we have explored involves the use of gold nanoparticles as carriers for gadolinium chelates. These nanoparticles are obtained by reducing a gold salt in the presence of a dithiolated derivative of DTPA. Characterization of these particles by transmission electron microscopy (TEM), X‐ray diffraction (XRD), thermogravimetric analysis (TGA), colorimetric titration, and X‐ray photoelectron spectroscopy (XPS) reveals the presence of a multilayered shell containing about 150 ligands on 2–2.5 nm sized particles. These particles exhibit a high relaxivity (r1 = 585 mM–1 s–1 as compared to 3.0 mM–1 s–1 for DTPA:Gd), rendering them very attractive as contrast agents for MRI

    Genetic screening of male patients with primary hypogammaglobulinemia can guide diagnosis and clinical management

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    International audienceThe precise diagnosis of an immunodeficiency is sometimes difficult to assess, especially due to the large spectrum of phenotypic variation reported among patients. Common variable immunodeficiency disorders (CVID) do not have, for a large part, an identified genetic cause. The identification of a causal genetic mutation is important to confirm, or in some cases correct, the diagnosis. We screened >150 male patients with hypogammaglobulinemia for mutations in three genes involved in pediatric X-linked primary immunoglobulin deficiency: CD40LG, SH2D1A and BTK. The SH2D1A screening allowed to reclassify two individuals with an initial CVID presentation as XLP after mutations identification. All these mutations were associated with a lack of protein expression. In addition, 4 patients with a primary diagnosis of CVID and one with a primary IgG subclass deficiency were requalified as XLA after identifying BTK mutations. Interestingly, two out of these 5 patients carried a damaging coding BTK mutation associated with a lower, but detectable, BTK expression in monocytes, suggesting that a dysfunctional protein explains the disease phenotype in these patients. In conclusion, our results advocate to include SH2D1A and BTK in newly developed targeted NGS genetic testing, to contribute to providing the most appropriate medical treatment and genetic counselling
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