299 research outputs found
Cholangiocytes: Cell transplantation
Background:Due to significant limitations to the access to orthotropic liver transplantation, cell therapies forliver diseases have gained large interest worldwide.Scope of review:To revise current literature dealing with cell therapy for liver diseases. We discussed the ad-vantages and pitfalls of the different cell sources tested so far in clinical trials and the rationale underlying thepotential benefits of transplantation of human biliary tree stem cells (hBTSCs).Major conclusions:Transplantation of adult hepatocytes showed transient benefits but requires immune-sup-pression that is a major pitfall in patients with advanced liver diseases. Mesenchymal stem cells and hemato-poietic stem cells transplanted into patients with liver diseases are not able to replace resident hepatocytes butrather they target autoimmune or inflammatory processes into the liver. Stem cells isolated from fetal or adultliver have been recently proposed as alternative cell sources for advanced liver cirrhosis and metabolic liverdisease. We demonstrated the presence of multipotent cells expressing a variety of endodermal stem cell markersin (peri)-biliary glands of bile ducts in fetal or adult human tissues, and in crypts of gallbladder epithelium. Inthefirst cirrhotic patients treated in our center with biliary tree stem cell therapy, we registered no adverse eventbut significant benefits.General significance:The biliary tree stem cell could represent the ideal cell source for the cell therapy of liverdiseases. This article is part of a Special Issue entitled: Cholangiocytes in Health and Diseaseedited by JesusBanales, Marco Marzioni, Nicholas LaRusso and Peter Jansen
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Ecosafety Assessment Of Cellulose-based Nanosponges Engineered For Marine Environmental Remediation In Sea Urchin Reproduction
A potential solution to marine pollution is the promising strategy of nanoremediation. Cellulose-based Nanosponges (CNS) were developed as eco-friendly and sustainable engineered materials for marine environmental remediation. This research aimed to assess the suitability of standardised bioassays, i.e. the spermiotoxicity and embryotoxicity assays, with the sea urchin Paracentrotus lividus in evaluating the safety of CNS. These tests were developed to screen the conventional contaminant toxicity and, thereby, may not be appropriate to evaluate the toxicity of nanomaterials due to their unique properties. Moreover, the eligibility of the sea urchin Arbacia lixula as a possible suitable alternative species in ecotoxicity testing has been investigated. For this species, appropriate bioassays have been developed since, to date, standardised procedures are not available. The obtained ecotoxicity data indicate that the two sea urchin species have a similar CNS sensitivity supporting the use of A. lixula in the ecotoxicity tests and that standardised bioassays with P. lividus are valuable tools for assessing the environmental impact of engineered material. In the framework of the reproductive risk assessment process that is beginning to expand, with new tests and endpoints, the traditional approach, based only on fertility and viable offspring as estimated endpoints, a new bioassay, named ovotoxicity test, has been developed to evaluate the potential CNS effects also on fertilisation competence of female gamete as well as a gamete quality assessment, in which gamete quality parameters underlying fertilisation and developmental competence were assessed as endpoints to screen the CNS impact on gamete quality. Overall, the ecotoxicity data indicate that CNS can affect gamete quality, gamete fertilisation competence, and embryo development due to a release of chemical additives from the manufacturing process. Hence, in the framework of the eco-design approach, these data suggest a re-design of CNS to obtain a safer device
IL DE REGNO DI SINESIO DI CIRENE E L'IDEOLOGIA IMPERIALE BIZANTINA TRA V E VI SECOLO
1. Lâenjeu de la recherche
Le but principal de la thĂšse est lâanalyse de lâapport du De regno de SynĂ©sios de CyrĂšne Ă la transmission de lâidĂ©ologie politique antique aux Ve et VIe siĂšcles de lâĂ©poque byzantine. Il sâagit, avant tout, de dĂ©finir lâidĂ©ologie politique de SynĂ©sios, dans le cadre de sa paideia alexandrine nĂ©oplatonicienne et chrĂ©tienne ; puis, de dĂ©terminer lâapport de son ouvrage Ă la formation de lâidĂ©ologie impĂ©riale et de la rhĂ©torique politique du Ve siĂšcle et de lâĂąge de Justinien. Afin de dĂ©terminer le rĂŽle du De regno de SynĂ©sios dans la transmission de ces topoi, on veut analyser les rapports entre cet ouvrage et les Ćuvres les plus reprĂ©sentatives de la littĂ©rature politique des Ve-VIe siĂšcles : le PanĂ©gyrique pour lâempereur Anastase de Procope de Gaza , la Scheda Regia dâAgapetus le Diacre , lâanonyme dialogue philosophique Sur la Science politique dĂ©diĂ© Ă Justinien et le traitĂ© Des magistratures de lâEtat romain de Jean le Lydien .
2. LâĂ©tat de la recherche
2.1. Le dĂ©bat sur la valeur historique et la chronologie de lâĆuvre
Les premiĂšres notes chronologiques au De regno, dans le cadre dâune reconstruction gĂ©nĂ©rale de la chronologie des opuscula de SynĂ©sios, sont dues Ă Otto Seeck (op. cit.), qui datait le De regno des annĂ©es 399-402. LâintĂ©rĂȘt pour les aspects historiques et politiques de lâĆuvre est dominant dans la critique italienne des annĂ©es 1920-1940, Ă cause de lâutilisation idĂ©ologique de la figure de SynĂ©sios pendant la colonisation italienne de la Libye. La premiĂšre monographie sur lâactivitĂ© politique de SynĂ©sios remonte Ă 1938, de claire inspiration fasciste, rĂ©digĂ©e par Giulio Bettini ; en 1944 est publiĂ©e lâ Ă©dition critique du De regno, par Nicola Terzaghi . Cette Ă©dition constitue la base pour les Ă©tudes suivantes. Pendant la deuxiĂšme partie du XXe siĂšcle, lâapproche historique est encore prĂ©valente, comme on peut le voir dans les pages consacrĂ©es au De regno dans la monographie de 1951 de Christian Lacombrade et dans son introduction Ă lâĂ©dition du De regno datant de la mĂȘme annĂ©e. On doit attendre les annĂ©es 1970 pour relever un renouvellement de lâintĂ©rĂȘt pour lâĆuvre.
En 1973, Antonio Garzya publie une traduction italienne du De regno, intĂ©grĂ©e dans son Ă©dition des opera omnia de SynĂ©sios de 1989, avec quelques notes de commentaire. Dans les annĂ©es 1980 la critique recommence Ă interroger spĂ©cifiquement cet ouvrage du CyrĂ©nĂ©en, encore selon une perspective chronologique. On dĂ©bat de la question de la datation du De regno. La querelle oppose ceux qui le datent des annĂ©es 399-402 (Denis Roques , suivi par Antonio Garzya ) et ceux qui proposent une datation plus haute, dans les annĂ©es 397-400 . Le dĂ©bat se dĂ©veloppe sur la base dâune diffĂ©rente interprĂ©tation des tĂ©moignages autobiographiques sur lâambassade Ă Constantinople que lâon trouve dans le corpus mĂȘme de SynĂ©sios : (Syn., De regn. 3 Terzaghi) lâoccasion du don de lâaurum coronarium ; (Syn., Ep. 61 Garzya-Roques) un tremblement de terre cause la fin du sĂ©jour constantinopolitain de SynĂ©sios ; (Syn., Hymn. I 428 â 433 Terzaghi ; De insomn. 14 Terzaghi) : le sĂ©jour de SynĂ©sios Ă Constantinople dure trois annĂ©es. En plus de lâintĂ©rĂȘt purement chronologique, pendant les mĂȘmes annĂ©es, se dĂ©veloppe la recherche sur la valeur plus gĂ©nĂ©ralement historique et idĂ©ologique du De regno dans ses rapports avec le contexte de la semi-barbare cour constantinopolitaine et de la CyrĂ©naĂŻque tardive . Dans ces contributions ne manquent pas quelques sporadiques rĂ©fĂ©rences aux aspects littĂ©raires du De regno. Beaucoup dâimportance est, par contre, donnĂ©e Ă la forme rhĂ©torique du discours dans lâintroduction Ă la derniĂšre Ă©dition critique du De regno (pp. 26-35), publiĂ©e par Jacques Lamoureux et NoĂ«l Aujoulat en 2008 .
3. LâidĂ©ologie impĂ©riale de SynĂ©sios de CyrĂšne dans le Discours sur la RoyautĂ©
Le De regno sâinscrit dans la tradition de la littĂ©rature antique sur la royautĂ©, qui a fleuri dans les milieux acadĂ©miques et stoĂŻciens, que nous connaissons par des auteurs comme Plutarque, Dion Chrysostome, ThĂ©mistios, mais quâillustraient aussi des auteurs perdus comme Ecphante, DiotogĂšne et Sthenidas. Son auteur avait Ă©galement une connaissance approfondie des thĂ©ories monarchiques judaĂŻques, transmises en particulier par Philon. Le CyrĂ©naĂŻque ne semble pas non plus Ă©tranger aux polĂ©miques thĂ©ologiques dont il a sans doute Ă©tĂ© le contemporain : la connaissance directe de Jean Chrysostome et le voisinage des patriarches dâAlexandrie ont dĂ» contribuer Ă la formation dâun nĂ©oplatonisme chrĂ©tien singulier, qui sâĂ©panouira dans les annĂ©es de la maturitĂ© et de lâĂ©piscopat.
SynĂ©sios dĂ©rive de la philosophie politique dâEusĂšbe, nourrie de topoi issus de Dion Chrysostome et ThĂ©mistios, une conception de lâEmpire comme don de la divinitĂ© au ÎČαÏÎčλΔÏÏ. Celui-ci est tenu de prĂ©server ce don Ă travers lâáŒÏÎșηÏÎčÏ continue de sa propre vertu.
Une autre pierre angulaire de lâidĂ©ologie impĂ©riale sinĂ©sienne est la supĂ©rioritĂ© du ÎœÏÎŒÎżÏ sur la maniĂšre dont le ÎČαÏÎčλΔÏÏ conduit sa propre vie. La vie de lâEmpereur, qui a valeur exemplaire pour ses sujets, est elle-mĂȘme le reflet de lâIdĂ©e dâune loi transcendante, respectueuse de lâordre cosmique et providentiel.
LâidĂ©e de lâEmpereur comme ÎœÏÎŒÎżÏ áŒÎŒÏÏ
ÏÎżÏ nâest formulĂ©e quâimplicitement par SynĂ©sios, alors que lâidĂ©e du souverain ÎŒÎčΌηÏáœŽÏ ÏοῊ ΞΔοῊ, sur laquelle la premiĂšre se fonde, est tout Ă fait explicite. Imitateur de Dieu, le souverain est son homonyme. Il partage ses attributs, mais pas sa nature.
Les vertus que le souverain doit dĂ©montrer, ÏÏÏΜηÏÎčÏ e áż„ÏΌη, sont tout Ă fait classiques, de mĂȘme que les attributs de la royautĂ©, Ă savoir bontĂ©, piĂ©tĂ© et autarcie, dont la possession est garantie au souverain par la relation dâhomonymie qui le relie Ă la divinitĂ©. Ces vertus ont une valeur universelle mais pas absolue, dans la mesure oĂč elles existent seulement selon une relation de cause Ă effet entre la divinitĂ© et lâobjet qui en expĂ©rimente les qualitĂ©s. Sur cette justification du principe de lâáœÎŒÎżÎŻÏÏÎčÏ ÏοῊ ΞΔοῊ, lâinfluence de la mĂ©taphysique aristotĂ©licienne est Ă©vidente avec lâontologie du premier principe, auquel SynĂ©sios fait une allusion efficace et directe, tout en la conjuguant avec lâidĂ©e nĂ©oplatonicienne de la divinitĂ© surabondante et dispensatrice de bienfaits.
Dans le De regno, le thĂšme de lâautarcie du souverain est investi dâune force particuliĂšre grĂące Ă la thĂ©orie platonicienne de lâĂąme complexe. Lâautarcie constitue le fondement du bon gouvernement, dans la mesure oĂč le roi est celui qui parvient Ă rĂ©unir sous lâĂ©gide de la raison le peuple agitĂ©, esclave de ses propres passions (De regn. 10).
LâesthĂ©tique de la royautĂ© joue un rĂŽle paradigmatique et fonctionnel dans la transmission de lâeusychia divine au monde. LâexemplaritĂ© de la vie du souverain exige quâil communie avec lâensemble de la vie sociale, que ce soit avec les fonctionnaires quâil a choisis, Ă travers la ÏÎčλία comme vertu, ou avec lâarmĂ©e, par le biais de lâáŒÏÎżÏ que fait naĂźtre au sein des troupes la vision du souverain comme membre dâune seule et mĂȘme famille.
Un autre aspect important de la thĂ©orie politique sinĂ©sienne est la conception unitaire de lâEmpire, dont tĂ©moigne le recours frĂ©quent Ă lâadresse conjointe Ă Arcadius et Ă son frĂšre Honorius, expression unique dâune institution universelle dont la division entre la partie orientale et la partie occidentale est seulement administrative.
ChargĂ© de faire la paix comme la guerre, conformĂ©ment aux topoi du genre du logos basilikĂČs, le souverain aura pour tĂąche primordiale de maintenir sa vertu philanthropique, lâamour du genre humain. La valeur de psychagogie que revĂȘt la philanthropie impĂ©riale, et dont dĂ©pend le salut de lâĂtat, est elle-mĂȘme un dĂ©rivĂ© de la philosophie comme vertu suprĂȘme, et traditionnellement attachĂ©e Ă la royautĂ©n (Syn., De regn. 29).
La dĂ©finition de lâEmpereur comme philosophe drapĂ© dans la pourpre, formulĂ©e par ThĂ©mistios, nâest pas reprise dans la royautĂ© sinĂ©sienne en raison dâune opposition vigoureuse au luxe dâinspiration cynique que lâon trouve chez SynĂ©sios. En revanche, lâamour de la philosophie et du cursus de la paideia classique devient chez lui la cause et la fin de la royautĂ©.
4. Lâinfluence du De regno de SynĂ©sios sur lâidĂ©ologie impĂ©riale byzantine des Ve et VIe siĂšcles
Lâanalyse des rapports entre le De regno de SynĂ©sios et le PanĂ©gyrique pour lâEmpereur Anastase de Procope de Gaza, la Scheda Regia dâAgapet le Diacre, lâanonyme dialogue Sur la Science politique et le traitĂ© Sur les magistratures de lâĂ©tat romain de Jean le Lydien nous a permis de tracer des pistes de lâinfluence de la thĂ©orie politique de SynĂ©sios sur le developpement de lâidĂ©ologie politique suivante, sourtout pour ce qui concerne les topoi du roi loi vivante et imitateur de Dieu. Lâexamen approfondi que nous avons rĂ©alisĂ© au sujet du De regno de SynĂ©sios nous permet de considĂ©rer que cette Ćuvre occupe une place centrale dans lâhistoire des idĂ©es politiques byzantines, et quâelle marque le passage dâune idĂ©ologie de la royautĂ© comprise et reprĂ©sentĂ©e selon les topoi de facture classique et hellĂ©nistique Ă une thĂ©orie politique qui enrichit ces topoi dâarguments mĂ©taphysiques et ontologiques nĂ©o-platoniciens dâun cĂŽtĂ©, de lâautre dâĂ©lĂ©ments moraux, universalistes et eschatologiques de plus en plus chrĂ©tiens. Sur le genre de discours auquel il appartient, le De regno de SynĂ©sios semble avoir exercĂ© une influence importante, y compris sur la dĂ©finition de la finalitĂ© de la littĂ©rature ΠΔÏ᜶ ÎČαÏÎčÎ»Î”ÎŻÎ±Ï : la pluralitĂ© des formes rhĂ©toriques analysĂ©es (le panĂ©gyrique, le speculum principis en forme dâacrostiche, le dialogue philosophique, le traitĂ©) traduit la recherche dâune forme dâexpression qui puisse vĂ©hiculer un contenu philosophique et instituer un rapport de type pĂ©dagogique entre lâauteur et son destinataire. Il est difficile de dire avec certitude dans quels milieux culturels et gĂ©ographiques le De regno a circulĂ© entre le Ve et VIe siĂšcles. Il est toutefois certain que les auteurs qui se rĂ©fĂšreront au De regno ont tous Ă©tĂ© en lien avec le courant du nĂ©o-platonisme chrĂ©tien. Alexandrie, Gaza, Constantinople, Antioche ou Beyrouth deviennent Ă cette Ă©poque des centres de propagation dâune nouvelle culture rĂ©unissant dans de nombreuses crĂ©ations les apports de lâhellĂ©nisme, de la tradition politique romaine et de la morale chrĂ©tienne. Le De regno de SynĂ©sios constitue un apport remarquable Ă cette nouvelle culture et constitue lâune des Ćuvres les plus reprĂ©sentatives de la SpĂ€tantike
Intrahepatic cholangiocarcinoma: review and update
Cholangiocarcinoma (CCA) is a heterogeneous group of malignancies that could develop at any level from the biliary tree. CCA is currently classified into intrahepatic (iCCA), perihilar and distal on the basis of its anatomical location. Of note, these three CCA subtypes have common features but also important inter-tumor and intra-tumor differences that can affect the pathogenesis and outcome. A unique feature of iCCA is that it recognizes as origin tissues, the hepatic parenchyma or large intrahepatic and extrahepatic bile ducts, which are furnished by two distinct stem cell niches, the canals of Hering and the peribiliary glands, respectively. The complexity of iCCA pathogenesis highlights the need of a multidisciplinary, translational and systemic approach to this malignancy. This review will focus on the advances of iCCA epidemiology, histo-morphology, risk factors, molecular pathogenesis, revealing the existence of multiple subsets of iCCA
Galectin 1-A Key Player between Tissue Repair and Fibrosis
Galectins are ten family members of carbohydrate-binding proteins with a high affinity for ÎČ galactose-containing oligosaccharides. Galectin-1 (Gal-1) is the first protein discovered in the family, expressed in many sites under normal and pathological conditions. In the first part of the review article, we described recent advances in the Gal-1 modulatory role on wound healing, by focusing on the different phases triggered by Gal-1, such as inflammation, proliferation, tissue repair and re-epithelialization. On the contrary, Gal-1 persistent over-expression enhances angiogenesis and extracellular matrix (ECM) production via PI3K/Akt pathway activation and leads to keloid tissue. Therefore, the targeted Gal-1 modulation should be considered a method of choice to treat wound healing and avoid keloid formation. In the second part of the review article, we discuss studies clarifying the role of Gal-1 in the pathogenesis of proliferative diabetic retinopathy, liver, renal, pancreatic and pulmonary fibrosis. This evidence suggests that Gal-1 may become a biomarker for the diagnosis and prognosis of tissue fibrosis and a promising molecular target for the development of new and original therapeutic tools to treat fibrosis in different chronic diseases
Somatic Mutational Landscape of Splicing Factor Genes and Their Functional Consequences across 33 Cancer Types
Hotspot mutations in splicing factor genes have been recently reported at high frequency in hematological malignancies, suggesting the importance of RNA splicing in cancer. We analyzed whole-exome sequencing data across 33 tumor types in The Cancer Genome Atlas (TCGA), and we identified 119 splicing factor genes with significant non-silent mutation patterns, including mutation over-representation, recurrent loss of function (tumor suppressor-like), or hotspot mutation profile (oncogene-like). Furthermore, RNA sequencing analysis revealed altered splicing events associated with selected splicing factor mutations. In addition, we were able to identify common gene pathway profiles associated with the presence of these mutations. Our analysis suggests that somatic alteration of genes involved in the RNA-splicing process is common in cancer and may represent an underappreciated hallmark of tumorigenesis
cholangiocarcinomas new insights from the discovery of stem cell niches in peribiliary glands of the biliary tree
Peribiliary glands (PBGs) are located in the large intrahepatic and extrahepatic bile ducts. Although they were described many years ago, their functions have been elucidated only in the last couple of years when our group demonstrated that PBGs are niches of multipotent stem/progenitor cells of endodermal origin. These cells express genes of multipotency and can be rapidly differentiatedin vitrointo hepatocytes, cholangiocytes, and endocrine pancreatic cells. PBGs share common features, in terms of stem/progenitor cell niches, with pancreatic duct glands and colon crypts, glandular structures representing in the adult life the endodermal remnants of fetal life. PBG stem/progenitor cells participate in the renewal of surface biliary epithelium and are active players in chronic pathologies of the biliary tree as well as in cholangiocarcinomas (CCA). Specifically, a large amount of recent evidence indicates that the pure mucin-CCA originates from PBGs; this could explain the similarities with pancreatic ductal adenocarcinoma and colorectal cancer, which also originate from transformed gland cells. In this paper, we summarized our recent findings concerning structure and functions of PBGs with the implications for liver pathophysiology and, specifically, for cancers of the biliary tree
Sperm Motility Impairment in Free Spawning Invertebrates Under Near-Future Level of Ocean Acidification: Uncovering the Mechanism
Ocean acidification (OA) refers to the decrease in ocean water pH resulting from the increasing absorption of atmospheric CO2. This will cause changes in the ocean's carbonate chemistry system with a resulting impact on reproduction of marine organisms. Reproduction is the fundamental process that allows the conservation of the species; in free-spawning marine invertebrates, this process is highly sensitive to changes in seawater quality and chemistry. To date, the majority of the studies concerned OA effects on reproduction has been focused on embryo and larval development. Despite several evidence for the impairment of reproductive success by environmental perturbations through altering gamete quality, sperm physiological responses to OA are poorly investigated. In this study, we evaluated the effects of exposure to acidified seawater (AcSW) (pH 7.8), which approximate the predicted global averages for oceanic surface waters at the end of this century, on sperm quality of the mussel Mytilus galloprovincialis and the ascidian Ciona robusta by evaluating several endpoints, such as motility, vitality, mitochondrial activity, oxidative state, and intracellular pH (pHi). Following sperm exposure to AcSW, the percentage of motile spermatozoa, mitochondrial activity and pHi decreased in comparison to the current seawater pH of 8.1, whereas vitality and oxidative state were unaffected by the low external pH in both the species. In broadcast spawners, a relationship between sperm intracellular pH and the initiation of motility are well known. Spermatozoa are immotile in the testes and motility is induced after the spermatozoa are released into seawater; the alkaline pH of seawater, in fact, increases the pHi activating motility and mitochondrial respiration. The results of this study suggest that the lowering of seawater pH as predicted to occur for 2100, through the inhibition of pHi increase, prevent sperm motility activation. Sperm motility is a key determinant of fertilization success; consequently, a corresponding drop in fertilization success would be expected with important implications for the fitness and the survival of marine invertebrates
The efficacy and the safety of eltrombopag in pediatric patients with severe aplastic anemia: a systematic review
BackgroundAcquired aplastic anemia (AAA) in pediatric patients is a rare disorder characterized by hypocellular bone marrow and pancytopenia. Eltrombopag, an oral thrombopoietin receptor agonist, provides a hematologic improvement in adults with severe aplastic anemia (SAA) refractory to immunosuppressive therapy (IST). The association of ELT and IST was approved by the US Food and Drug Administration (FDA) for adults and children â„2 years of age as a first-line treatment for SAA. However, the effects of ELT on pediatric patients with SAA remain controversial and limited.Methods and findingsWe conducted a systematic review of the most recent literature from Pubmed, Web of Science, and Embase, published up to 20th December 2022, in order to evaluate the available evidence on the efficacy and safety of ELT added to IST for the treatment of SAA in the pediatric population.ConclusionEltrombopag added to the IST has shown a good safety profile, without manifestations of excessive toxic effects, although not all the results obtained from our studies support the addition of ELT to the IST in the first-line treatment of children with SAA.Systematic Review Registrationhttps://www.crd.york.ac.uk/prospero/, identifier: CRD42022325859
Autophagy: A Novel Pharmacological Target in Diabetic Retinopathy
Autophagy is the major catabolic pathway involved in removing and recycling damaged macromolecules and organelles and several evidences suggest that dysfunctions of this pathway contribute to the onset and progression of central and peripheral neurodegenerative diseases. Diabetic retinopathy (DR) is a serious complication of diabetes mellitus representing the main preventable cause of acquired blindness worldwide. DR has traditionally been considered as a microvascular disease, however this concept has evolved and neurodegeneration and neuroinflammation have emerged as important determinants in the pathogenesis and evolution of the retinal pathology. Here we review the role of autophagy in experimental models of DR and explore the potential of this pathway as a target for alternative therapeutic approaches
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