Ruxolitinib in the treatment of polycythemia vera: patient selection and special considerations.

The discovery of JAK2 V617F mutation in the mid-2000s started to fill the gap between clinical presentation of polycythemia vera (PV), first described by Vaquez at the end of the 19th century, and spontaneous erythroid colony formation, reported by Prchal and Axelrad in the mid-1970s. The knowledge on this mutation brought an important insight to our understanding of PV pathogenesis and led to a revision of the World Health Organization diagnostic criteria in 2008. JAK-STAT is a major signaling pathway implicated in survival and proliferation of hematopoietic precursors. High prevalence of JAK2 V617F mutation among myeloproliferative neoplasms (>95% in PV and ~50% in primary myelofibrosis and essential thrombocythemia) together with its role in constitutively activating JAK-STAT made JAK2 a privileged therapeutic target. Ruxolitinib, a JAK 1 and 2 inhibitor, has already proven to be efficient in relieving symptoms in primary myelofibrosis and PV. In the latter, it also appears to improve microvascular involvement. However, evidence regarding its potential role in altering the natural course of PV and its use as an adjunct to current standard therapies is sparse. Therapeutic advances are needed in PV as phlebotomy, low-dose aspirin, cytoreductive agents, and interferon alpha are the only therapeutic tools available at the moment to influence outcome. Even though several questions are still unanswered, this review aims to serve as an overview article of the potential role of ruxolitinib in PV according to current literature and expert opinion. It should help hematologists to visualize the place of this tyrosine kinase inhibitor in the field of current practice and offer criteria for a careful patient selection

Transverse momentum fluctuations and percolation of strings

The behaviour of the transverse momentum fluctuations with the centrality of the collision shown by the Relativistic Heavy Ion Collider data is naturally explained by the clustering of color sources. In this framework, elementary color sources --strings-- overlap forming clusters, so the number of effective sources is modified. These clusters decay into particles with mean transverse momentum that depends on the number of elementary sources that conform each cluster, and the area occupied by the cluster. The transverse momentum fluctuations in this approach correspond to the fluctuations of the transverse momentum of these clusters, and they behave essentially as the number of effective sources.Comment: 16 pages, RevTex, 4 postscript figures. Enhanced version. New figure

Farnesoid X receptor and liver X receptor ligands initiate formation of coated platelets

The liver X receptors (LXRs) and farnesoid X receptor (FXR) have been identified in human platelets. Ligands of these receptors have been shown to have nongenomic inhibitory effects on platelet activation by platelet agonists. This, however, seems contradictory with the platelet hyper-reactivity that is associated with several pathological conditions that are associated with increased circulating levels of molecules that are LXR and FXR ligands, such as hyperlipidemia, type 2 diabetes mellitus, and obesity. We, therefore, investigated whether ligands for the LXR and FXR receptors were capable of priming platelets to the activated state without stimulation by platelet agonists. Treatment of platelets with ligands for LXR and FXR converted platelets to the procoagulant state, with increases in phosphatidylserine exposure, platelet swelling, reduced membrane integrity, depolarization of the mitochondrial membrane, and microparticle release observed. Additionally, platelets also displayed features associated with coated platelets such as P-selectin exposure, fibrinogen binding, fibrin generation that is supported by increased serine protease activity, and inhibition of integrin αIIbβ3. LXR and FXR ligand-induced formation of coated platelets was found to be dependent on both reactive oxygen species and intracellular calcium mobilization, and for FXR ligands, this process was found to be dependent on cyclophilin D. We conclude that treatment with LXR and FXR ligands initiates coated platelet formation, which is thought to support coagulation but results in desensitization to platelet stimuli through inhibition of αIIbβ3 consistent with their ability to inhibit platelet function and stable thrombus formation in vivo

Aislamiento, cultivo y caracterización de líneas celulares embrionarias bovinas

Isolation, culture, and characterization of embryonic cell lines from bovine blastocysts This study was aimed to develop methods for isolation, culture and characterization of embryonic cell lines from in vitro produced bovine blastocysts. Inner cell masses arising from blastocysts were isolated by immunosurgery onto mitomocin-C-inactivated mouse embryonic fibroblast (MEF). After 10 to 15 days of culture the primary cell colonies were disaggregated, seeded in a new MEF, and cultured for 3 to 6 days up to form new colonies. The primary cell colonies, passage 2, passage 3 and post-thawed colonies expressed pluripotency markers such us SSEA-4, TRA-1-60 and Oct4 and were alkaline phosphatase positive. More research is needed to confirm pluripotency and selfrenew stage within the obtained embryonic stem-like cells (ES-like).El objetivo principal de este trabajo es el aislamiento, cultivo y caracterización de líneas embrionarias producidas a partir del aislamiento de masa celular interna (MCI) de blastocisto bovino. Las MCI se aislaron mediante inmunocirugía y se cultivaron en monocapas de fibroblastos embrionarios de ratón (MEF) mitóticamente inactivados. Tras 10-15 días de cultivo primario, las colonias surgidas se disgregaron, resembraron en una nueva MEF, y cultivaron por tiempo variable para tratar de obtener nuevas colonias. Tanto los cultivos primarios como los pases 2 y 3, así como las colonias supervivientes a la congelación, expresaron los marcadores de pluripotencia SSEA-4, TRA-1-60 y Oct4, y fueron positivos al test de la fosfatasa alcalina. A falta de pruebas para el diagnóstico de la pluripotencia y capacidad de autorrenovación, las células obtenidas presentan parte de las características de las células troncales embrionarias (ES-like)

The Role of Plasma Transfusion in Massive Bleeding: Protecting the Endothelial Glycocalyx?

Massive hemorrhage is a leading cause of death worldwide. During the last decade several retrospective and some prospective clinical studies have suggested a beneficial effect of early plasma-based resuscitation on survival in trauma patients. The underlying mechanisms are unknown but appear to involve the ability of plasma to preserve the endothelial glycocalyx. In this mini-review, we summarize current knowledge on glycocalyx structure and function, and present data describing the impact of hemorrhagic shock and resuscitation fluids on glycocalyx. Animal studies show that hemorrhagic shock leads to glycocalyx shedding, endothelial inflammatory changes, and vascular hyper-permeability. In these animal models, plasma administration preserves glycocalyx integrity and functions better than resuscitation with crystalloids or colloids. In addition, we briefly present data on the possible plasma components responsible for these effects. The endothelial glycocalyx is increasingly recognized as a critical component for the physiological vasculo-endothelial function, which is destroyed in hemorrhagic shock. Interventions for preserving an intact glycocalyx shall improve survival of trauma patients

Principles of early human development and germ cell program from conserved model systems

Human primordial germ cells (hPGCs), the precursors of sperm and eggs, originate during week 2-3 of early postimplantation development(1). Using in vitro models of hPGC induction(2-4), recent studies suggest striking mechanistic differences in specification of human and mouse PGCs(5). This may partly be due to the divergence in their pluripotency networks, and early postimplantation development(6-8). Since early human embryos are inaccessible for direct studies, we considered alternatives, including porcine embryos that, as in humans, develop as bilaminar embryonic discs. Here we show that porcine PGCs (pPGCs) originate from the posterior pre-primitive streak competent epiblast by sequential upregulation of SOX17 and BLIMP1 in response to WNT and BMP signalling. Together with human and monkey in vitro models simulating peri-gastrulation development, we show conserved principles for epiblast development for competency for PGC fate, followed by initiation of the epigenetic program(9-11), regulated by a balanced SOX17–BLIMP1 gene dosage. Our combinatorial approach using human, porcine and monkey in vivo and in vitro models, provides synthetic insights on early human development

New tools in percutaneous minimally invasive chronic subdural hematomas evacuation

Background: Incidence of chronic subdural hematomas (cSDH) is expected to progressive rise in the next decades. There is no univocal indication of the approach to be used. Furthermore, there is no data about the efficacy of twist drill craniostomy (TDC) in hematomas with membranes. Objective: To describe our modified technique for TDC in patients affected by cSDH with membranes and in treatment with antiplatelets. Methods: We analyzed a group of 37 patients, affected by cSDH with membrane (type D laminar membrane and type G trabecular membrane according to Nakaguchi classification), treated with mushroom TDC using a modified technique. Results: After surgery the average maximum thickness of the common postoperative liquoral subdural collection decreased from 18.8 to 6.21 mm. We documented one acute subdural hematoma (2.7%), asymptomatic and not treated, and one recurrence of cSDH (2.7%) after 2 months that needed re-intervention with single burr hole. Conclusions: We presented a modified twist drill technique, characterized by the introduction of an application of a new device that optimizes both surgical results, clinical outcome and surgical procedure time. The presence of membrane type D and G does not affect the efficacy of drainage, that is negatively related to the presence of clots or acute hematoma. This modified technique is safe, fast, effective and represents a valid first line treatment of an unstable and unpredictable pathology such as cSDH. We suggest performing such technique on a larger patients’ cohort to further validate its effectiveness

The endogenous HBZ interactome in ATL leukemic cells reveals an unprecedented complexity of host interacting partners involved in RNA splicing

Adult T-cell leukemia/lymphoma (ATL) is a T-cell lymphoproliferative neoplasm caused by the human T-cell leukemia virus type 1 (HTLV-1). Two viral proteins, Tax-1 and HBZ play important roles in HTLV-1 infectivity and in HTLV-1-associated pathologies by altering key pathways of cell homeostasis. However, the molecular mechanisms through which the two viral proteins, particularly HBZ, induce and/or sustain the oncogenic process are still largely elusive. Previous results suggested that HBZ interaction with nuclear factors may alter cell cycle and cell proliferation. To have a more complete picture of the HBZ interactions, we investigated in detail the endogenous HBZ interactome in leukemic cells by immunoprecipitating the HBZ-interacting complexes of ATL-2 leukemic cells, followed by tandem mass spectrometry analyses. RNA seq analysis was performed to decipher the differential gene expression and splicing modifications related to HTLV-1. Here we compared ATL-2 with MOLT-4, a non HTLV-1 derived leukemic T cell line and further compared with HBZ-induced modifications in an isogenic system composed by Jurkat T cells and stably HBZ transfected Jurkat derivatives. The endogenous HBZ interactome of ATL-2 cells identified 249 interactors covering three main clusters corresponding to protein families mainly involved in mRNA splicing, nonsense-mediated RNA decay (NMD) and JAK-STAT signaling pathway. Here we analyzed in detail the cluster involved in RNA splicing. RNAseq analysis showed that HBZ specifically altered the transcription of many genes, including crucial oncogenes, by affecting different splicing events. Consistently, the two RNA helicases, members of the RNA splicing family, DDX5 and its paralog DDX17, recently shown to be involved in alternative splicing of cellular genes after NF-κB activation by HTLV-1 Tax-1, interacted and partially co-localized with HBZ. For the first time, a complete picture of the endogenous HBZ interactome was elucidated. The wide interaction of HBZ with molecules involved in RNA splicing and the subsequent transcriptome alteration strongly suggests an unprecedented complex role of the viral oncogene in the establishment of the leukemic state

Efecto de la adición atrasada de suero fetal bovino al medio de cultivo sobre la producción in vitro de embriones de novillas criollas criadas a gran altura en el Ecuador

El estudio tuvo como objetivo evaluar el efecto del suero fetal bovino (FCS) agregado al medio de cultivo los días 5 a 7 después de la fertilización in vitro sobre la producción y posterior criotolerancia de blastocistos de vaquillonas criollas ecuatorianas. Se recolectaron complejos cúmulo-ovocitos (COCs) inmaduros mediante aspiración intravaginal guiada por ultrasonido (OPU) de 10 vaquillonas criollas y de ovarios de matadero en ocho sesiones. Los COCs se sometieron a maduración in vitro (MIV), fecundación (FIV) y cultivo (IVC). El día 1 después de la FIV, los presuntos embriones de cada fuente de ovocitos (OPU [O] y Matadero [A]) se asignaron aleatoriamente en dos grupos según si se añadió FCS al 2.5% (v/v) al medio de cultivo el día 5 después de la FIV: 1) O-FCS+, 2) O-FCS-, 3) A-FCS+ y 4) A-FCS-. El día 7 después de la FIV se vitrificaron embriones de alta calidad. La criotolerancia de los embriones vitrificados-calentados se evaluó según la reexpansión del blastocele a las 2 h y la posterior reexpansión y eclosión a las 24 y 48 h de incubación. La tasa de blastocistos el día 7 no difirió entre la fuente de ovocitos y el grupo FCS. Después del proceso de vitrificación/calentamiento, la adición de FCS solo afectó la tasa de reexpansión a las 2 h, independientemente de la fuente de ovocitos (p<0.05). Asimismo, la tasa de eclosión de los blastocistos a las 48 h de incubación se vio drásticamente afectada únicamente en los ovocitos derivados de OPU (p<0.01). En conclusión, la suplementación de FCS el día 5 después de la FIV no mejoró la producción de blastocistos y afectó negativamente la criotolerancia de embriones bovinos in vitro derivados de vaquillonas criollas criadas en los Andes ecuatorianos.This experiment aimed to assess the effect of fetal calf serum (FCS) added to culture medium on day 5 to 7 after in vitro fertilization on production and subsequent cryotolerance of blastocysts from Ecuadorian Creole heifers. Immature cumulus-oocyte complexes (COCs) were collected by ovum pick-up (OPU) from 10 Creole heifers and from ovaries collected at abattoir in eight collection sessions. COCs were subjected to in vitro maturation (IVM), fertilization (IVF), and culture (IVC). On day 1 after IVF, presumptive embryos from each oocyte source (OPU [O] and Abattoir [A]) were allocated randomly in two groups according to whether 2.5% (v/v) FCS was added to culture medium on day 5 after IVF: 1) O-FCS+, 2) O-FCS-, 3) A-FCS+, and 4) A-FCS-. On day 7 after IVF, high quality embryos were vitrified. Cryotolerance of vitrified-warmed embryos was assessed according to blastocele re-expansion at 2 h and subsequent re-expansion and hatching at 24 and 48 h of re-incubation. Blastocysts rate on day 7 did not differ between oocyte source and FCS group. After vitrification/warming process, addition of FCS affected the re-expansion rate only at 2 h, irrespective of the oocyte source (p<0.05). Likewise, blastocysts hatching rate at 48 h of incubation was drastically affected only in OPU-derived oocyte (p<0.01). Supplementation of FCS on day 5 after IVF did not improve blastocyst production and adversely affected the cryotolerance of in vitro bovine embryos derived from creole heifers raised on Ecuadorian Andean highlands

A gene expression atlas of the domestic pig

<p>Abstract</p> <p>Background</p> <p>This work describes the first genome-wide analysis of the transcriptional landscape of the pig. A new porcine Affymetrix expression array was designed in order to provide comprehensive coverage of the known pig transcriptome. The new array was used to generate a genome-wide expression atlas of pig tissues derived from 62 tissue/cell types. These data were subjected to network correlation analysis and clustering.</p> <p>Results</p> <p>The analysis presented here provides a detailed functional clustering of the pig transcriptome where transcripts are grouped according to their expression pattern, so one can infer the function of an uncharacterized gene from the company it keeps and the locations in which it is expressed. We describe the overall transcriptional signatures present in the tissue atlas, where possible assigning those signatures to specific cell populations or pathways. In particular, we discuss the expression signatures associated with the gastrointestinal tract, an organ that was sampled at 15 sites along its length and whose biology in the pig is similar to human. We identify sets of genes that define specialized cellular compartments and region-specific digestive functions. Finally, we performed a network analysis of the transcription factors expressed in the gastrointestinal tract and demonstrate how they sub-divide into functional groups that may control cellular gastrointestinal development.</p> <p>Conclusions</p> <p>As an important livestock animal with a physiology that is more similar than mouse to man, we provide a major new resource for understanding gene expression with respect to the known physiology of mammalian tissues and cells. The data and analyses are available on the websites <url>http://biogps.org and http://www.macrophages.com/pig-atlas</url>.</p