1,548 research outputs found
CORRECTION
No full textWhen the above article was first published online, the author name ‘David M. Smadja’ and his affiliation was published incorrectly. [...
Histo-cytochemistry and scanning electron microscopy of lavender glandular trichomes following conventional and microwave-assisted hydrodistillation of essential oils: a comparative study
No full textThe conventional hydrodistillation method (HD) has been compared with three different variants of the microwave-assisted hydrodistillation technique (MADH), on Lavandula anguslifolia flowers, both in terms of oil yield and effects on the glandular trichome morpho-structure. The amount and composition of essential oil extracted in 4 h by HD was similar to that obtained in only 20 min by MADH and even lower than that extracted with a steam variant (MASD) of MADH itself. Histo-cytochemical investigations and scanning electron microscopy showed that glandular trichome, after 4 h of HD, appeared swollen, with a deeply wrinkled surface and empty of essential oil, however maintaining the integrity of their cuticle. Many oil droplets were stuck to the outside of the trichome cuticle, sometimes arranged in large aggregates. After 20 min of MADH or MASD, trichomes appeared empty as well, but also particularly disrupted, or at least with holes in their head cuticle. Oil droplets were present outside the glands and in the inter-rib regions of the flower calyx, except in the case of MASD. After this extraction method, neither oil droplets nor other lipid staining were present in the samples, confirming the effectiveness of this particular MADH technique. These investigations suggest that the rapidity of MADH and MASD in extracting essential oil is mainly due to the collapse of trichome structure and the consequent direct release of its content, without which it has to slowly permeate through membranes and cuticle, as in the case of HD. Copyrigh
Characterization of endothelial stem/progenitor cells in postnatal vasculogenesis
No full textLa thérapie cellulaire dans l'artériopathie oblitérante des membres inférieurs (AOMI) est un domaine de recherche visant la régénération vasculaire notamment au stade d'ischémie critique où le membre inférieur est à risque d'amputation. Les succès mitigés des essais thérapeutiques réalisés peuvent provenir du produit de thérapie cellulaire utilisé, comme par exemple la moelle osseuse autologue supposée contenir les progéniteurs vasculaires. L'origine des Endothelial Colony-Forming Cells (ECFCs), le sous-type vasculogénique des cellules progénitrices endothéliales, reste encore inconnu. Dans un 1er article (1), nous avons rapporté que les very small embryonic-like stem cells (VSELs) présentes chez l'adulte sont capables d'auto-renouvèlement et de différenciation vers les 3 lignées germinales et seraient un bon candidat. L'équipe du Pr Smadja a démontré que les VSELs issues de moelle osseuse humaine pouvaient se différentier en cellules endothéliales et contribuer à la vasculogénèse. Dans un 2ème article en écriture j'ai participé à la caractérisation par cytométrie en flux des cellules immatures circulantes de patients porteurs d'un coeur artificiel CARMAT. L'existence d'une néo-endothélialisation au sein de ce coeur témoigne d'une colonisation par des progéniteurs cellulaires et nous avons démontré une mobilisation de cellules immatures circulantes dont des VSELs un mois après implantation. A l'aide du panel d'anticorps mis au point dans le travail précédent, afin de quantifier, isoler et expandre des VSELs circulantes chez des patients avec AOMI nous avons mis en place la collection biologique prospective monocentrique VESSELS (VEry Small embryonic like cellS Expandability in Lower limb arterial diSease), stratifiée sur les stades d'ischémie d'effort ou ischémie critique et associé ou non au diabète. Seuls 55 patients ont été inclus en lien avec les difficultés d'inclusion liée à l'épidémie COVID-19. Par ailleurs, les VSELs sont apparentées aux cellules germinales primordiales migratrices et prolifèrent ainsi sous l'action de gonadotrophines : l'hormone folliculo-stimulante (FSH) et l'hormone lutéinisante (LH). Le 3ème article soumis à Journal of Thrombosis and Haemostasis(2), vise à tester les propriétés angiogéniques des ECFCs issus de sang de cordon traités par FSH et LH. Nous avons pu montrer qu'elles augmentaient le potentiel angiogénique des ECFCs in vitro mais pas leur prolifération ni l'engagement en ECFCs des cellules mononuclées de sang de cordon. Par ailleurs, la génération de thrombine était accrue après culture par FSH et ces gonadotrophines étaient plus élevées chez les hommes avec AOMI comparés à leurs contrôles. Ces hormones pourraient ainsi jouer un rôle dans la physiopathologie de l'AOMI. Enfin dans un 4ème article en cours d'écriture, j'ai comparé les caractéristiques distinguant les hommes et les femmes hospitalisés pour AOMI. A la ménopause les gonadotrophines restent élevées en plateau et n'ont plus les variations liées aux cycles menstruels. Les femmes nécessitent une hospitalisation pour AOMI à un âge plus avancé que les hommes, et leur athérosclérose est plus diffuse. Nous allons ajouter l'analyse des profils hormonaux dans la collection biologique VESSELS afin de mieux comprendre l'implication des gonadotrophines dans l'AOMI. En perspective, VESSELS permettra d'appliquer les techniques de caractérisation des cellules immatures développées au cours de ma thèse, puis d'isoler et expandre les VSELs afin de pouvoir tester ces cellules comme produit de thérapie cellulaire. Références : 1. Detriche, G., Guerin, C. L., Gendron, N., Mirault, T. & Smadja, D. M. Do Endothelial Colony'forming Cells Come From Bone Marrow or Vessels/VSELs? Stem Cell Rev. Rep. (2021) doi:10.1007/s12015-021-10140-y. 2. Détriché, G. et al. Gonadotropins as new active partners in vascular diseases: insight from endothelial colony-forming cells angiogenic properties and thrombotic potential. J. Thromb. Haemost. submittedCell therapy in peripheral arterial disease of the lower limbs (PAD) is an area of research aimed at vascular regeneration, particularly at the stage of critical limb ischemia where the lower limb is at risk of amputation. The mixed successes of the therapeutic trials carried out may be due to the cell therapy product used, like bone marrow supposedly containing vascular progenitors. The origin of Endothelial Colony-Forming Cells (ECFCs), the vasculogenic subtype of endothelial progenitor cells, remains unknown. In a first article(1) we reported that very small embryonic-like stem cells (VSELs), present in adult bone marrow are capable of self-renewal and differentiation into the 3 germinal lineages and would be a good candidate. Pr Smadja's team demonstrated that VSELs derived from human bone marrow could differentiate into endothelial cells and contribute to vasculogenesis. In a 2nd article in progress, I participated in the characterization by flow cytometry of immature circulating cells from patients with a CARMAT artificial heart. The existence of an endothelialization of their implant testifies to a colonization by progenitor cells and we were able to demonstrate a mobilization of circulating immature cells including VSELs 1 month after implantation. With the help of the antibody panel developed in the previous work, in order to quantify, isolate and then expand circulating VSELs in PAD, I set up the prospective biological collection VESSELS (VEry Small embryonic-like cellS Expandability in Lower limb arterial diSease) stratified on the stages of ischemia: claudication or critical limb ischemia and with associated diabetes or not. Only 55 patients were included but the COVID19 pandemic delayed inclusion capabilities.VSELs are related to migrating primordial germ cells and thus proliferate under the action of gonadotropins: follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The 3rd article submitted to the Journal of Thrombosis and Haemostasis(2) aims at testing the angiogenic properties of ECFCs derived from cord blood and treated by FSH and LH. We demonstrated that they increased the angiogenic potential of ECFCs in vitro but not their proliferation or the commitment of cord blood mononuclear cells to ECFCs. Moreover, thrombin generation was increased by FSH and these gonadotropins were higher in men with PAD than in their controls. These hormones could thus play a role in the pathophysiology of PAD. Finally, in a 4th article in process, I compared the characteristics distinguishing men and women hospitalized for PAD. At menopause gonadotropins remain elevated in a plateau and have no longer the pulses associated with menstrual cycles. Women require hospitalization for PAD at a later age than men, and their atherosclerosis is more diffuse. Thus, we will add the analysis of hormonal profiles in the VESSELS biological collection to better understand the involvement of gonadotropins in PAD. In perspective, VESSELS will allow us to apply the characterization techniques of immature cells developed during my thesis, and then to isolate and expand VSELs in order to test these cells as a cell therapy product. References : 1. Detriche, G., Guerin, C. L., Gendron, N., Mirault, T. & Smadja, D. M. Do Endothelial Colony'forming Cells Come From Bone Marrow or Vessels/VSELs? Stem Cell Rev. Rep. (2021) doi:10.1007/s12015-021-10140-y. 2. Détriché, G. et al. Gonadotropins as new active partners in vascular diseases: insight from endothelial colony-forming cells angiogenic properties and thrombotic potential. J. Thromb. Haemost. submitted (2021)
Primary lymphoplasmacytic lymphoma of the liver associated with a serum monoclonal peak of IgG kappa.
No full textHemoperitoneum caused by a ruptured GIST located in the posterior gastric wall managed by endoscopic diagnosis and laparoscopic treatment: case report and literature review.
No full textA case of hemoperitoneum caused by a ruptured gastrointestinal stromal tumor (GIST) of the posterior gastric wall is presented. An otherwise healthy 81-year-old man presented with abdominal pain/tenderness and anemia (hemoglobin: 7.4 g/dL). Computed tomography scan showed hemoperitoneum and a gastric mass of uncertain nature. As the patient was hemodynamically stable, a mini-invasive approach was decided. Esophagogastroscopy revealed an umbilicated mass of the posterior gastric wall, therefore allowing for a correct preoperative diagnosis of GIST and its appropriate treatment by laparoscopic atypical gastrectomy. Laparoscopically, a longitudinal resection of gastric fundus including the tumor was performed in a sleeve gastrectomy fashion, 25 minutes after the induction of pneumoperitoneum. The outcome was uneventful. Pathologic examination confirmed a benign 4×3-cm gastric GIST with <1 mitosis per 50 high power field, staining positive for CD117 (C-KIT) and negative for S-100 protein and smooth muscle actin. To our knowledge, it is the first case of a successful laparoscopic resection of an endoscopically diagnosed gastric GIST in an emergency setting. Hemoperitoneum is a rare, potentially severe complication of GIST. As bleeding is rarely severe, most patients may benefit from a mini-invasive approach, even if the tumor is located in the posterior gastric wall
: Paris, Hermann, 2020. Collection « Monologuer ». 350 pages.
No full textInternational audienceIn her work Les Troubles du langage intérieur. Vers une linguistique clinique, S. Smadja adresses the subject of endophasia through the unusual perspective of its various pathologies and malfunctions (stuttering, aphasia, auditory verbal hallucination, rumination etc.). The author recounts the contentious history of clinical linguistics, the scientific field which deals with these issues, and introduces new therapeutic hypotheses, from an interdisciplinary viewpoint focusing on the ethics of care.Dans son ouvrage Les Troubles du langage intérieur. Vers une linguistique clinique, S. Smadja aborde la question de l’endophasie par le biais singulier de ses pathologies et dysfonctionnements (bégaiement, aphasie, hallucination auditive verbale, rumination etc.). L’autrice retrace l’histoire conflictuelle de la linguistique clinique qui prend en charge ces problématiques, et présente de nouvelles hypothèses thérapeutiques, dans une perspective interdisciplinaire résolument tournée vers l’éthique du soin
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