Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
1.
Science ; 364(6444): 981-984, 2019 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-31171695

RESUMEN

Galaxy clusters are the most massive gravitationally bound structures in the Universe. They grow by accreting smaller structures in a merging process that produces shocks and turbulence in the intracluster gas. We observed a ridge of radio emission connecting the merging galaxy clusters Abell 0399 and Abell 0401 with the Low-Frequency Array (LOFAR) telescope network at 140 megahertz. This emission requires a population of relativistic electrons and a magnetic field located in a filament between the two galaxy clusters. We performed simulations to show that a volume-filling distribution of weak shocks may reaccelerate a preexisting population of relativistic particles, producing emission at radio wavelengths that illuminates the magnetic ridge.

2.
Clin Appl Thromb Hemost ; 18(1): 79-86, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-21733935

RESUMEN

Patients with multiple myeloma (MM) are at relatively high risk of developing thromboembolic events such deep venous thrombosis (DVT) where thalidomide therapy has been identified to increase this risk. Defibrotide (DF), a polydisperse oligonucleotide, showed previously to counteract the alterations in endothelial cells (ECs) induced by lipopolysaccharide. It prompts us to investigate the impact of thalidomide on ECs and whether DF modulates changes in fibrinolysis induced by thalidomide. In this in vitro study, MM by itself alters the profibrinolytic potential of ECs decreasing the tissue plasminogen activator (t-PA) and increasing the plasminogen activator inhibitor 1 (PAI-1) levels which is potentiated by thalidomide. Defibrotide was able to counteract these effects. Additionally, DF upregulated the t-PA and downregulated PAI-1 gene expression modulated by thalidomide. Defibrotide also protects ECs from thalidomide-mediated cell death without interfering with its antitumor effects. These findings support DF clinical use for the prevention of DVT induced by immunomodulatory drugs.


Asunto(s)
Inhibidores de la Angiogénesis/farmacología , Células Endoteliales/metabolismo , Fibrinólisis/efectos de los fármacos , Fibrinolíticos/farmacología , Mieloma Múltiple/tratamiento farmacológico , Polidesoxirribonucleótidos/farmacología , Talidomida/farmacología , Trombosis de la Vena/prevención & control , Inhibidores de la Angiogénesis/efectos adversos , Inhibidores de la Angiogénesis/uso terapéutico , Muerte Celular/efectos de los fármacos , Línea Celular , Evaluación Preclínica de Medicamentos , Células Endoteliales/patología , Fibrinolíticos/uso terapéutico , Humanos , Mieloma Múltiple/complicaciones , Mieloma Múltiple/metabolismo , Mieloma Múltiple/patología , Polidesoxirribonucleótidos/uso terapéutico , Riesgo , Talidomida/efectos adversos , Talidomida/uso terapéutico , Activador de Tejido Plasminógeno/metabolismo , Trombosis de la Vena/inducido químicamente , Trombosis de la Vena/metabolismo
3.
Reprod Biomed Online ; 14(6): 675-81, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17579976

RESUMEN

Over the last two decades, easier and less expensive stimulation treatments have been largely replaced by more complex and more demanding protocols. Since the mid-nineties, long-term gonadotrophin-releasing hormone agonist stimulation protocols have been widely used. Such lengthy expensive regimens are not free from short- and long-term risks and complications. Mild stimulation protocols reduce the mean number of days of stimulation, the total amount of gonadotrophins used and the mean number of oocytes retrieved. The proportion of high quality and euploid embryos seems to be higher compared with conventional stimulation protocols and the pregnancy rate per embryo transfer is comparable. Moreover, the reduced costs, the better tolerability for patients and the less time needed to complete an IVF cycle make mild approaches clinically and cost-effective over a given period of time. However, further prospective randomized studies are needed to compare cumulative pregnancy rates between the two protocols. Natural cycle IVF, with minimal stimulation, has been recently proposed as an alternative to conventional stimulation protocols in normo- and poor responder patients. Although acceptable results have been reported, further large prospective randomized studies are needed to better evaluate the efficacy of these minimal regimens compared with conventional stimulation approaches.


Asunto(s)
Inducción de la Ovulación/métodos , Adulto , Transferencia de Embrión , Femenino , Fertilización In Vitro/métodos , Hormona Liberadora de Gonadotropina/agonistas , Humanos , Folículo Ovárico/fisiología , Embarazo , Índice de Embarazo
4.
Scand J Immunol ; 65(4): 329-35, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17386023

RESUMEN

Until recently, the only accepted mechanism of tumour vascularization was the sprouting of endothelial cells (EC) from pre-existing vessels, while recent studies suggest the contribution of stem cell-derived endothelial progenitors as well as cells from the myeloid lineage. Here, we show a new way of endothelial differentiation that involves the specific modulation of monocytes by the tumour environment. The tumour milieu is characterized by the presence of cytokines and lactate which induce the differentiation of tumour-invading monocytes into tumour-associated dendritic cells (DC). Additional incubation of tumour-associated DC with pro-angiogenic factors, such as vascular endothelial growth factor and oncostatin M, led to transdifferentiation into endothelial-like cells. The cells showed strong expression of von Willebrand factor and VE-Cadherin, both classical EC markers, while leukocytic markers were reduced. In addition, they were able to form network-like structures on matrigel, which could be blocked by the DNA-based drug Defibrotide. This finding may be of great therapeutic relevance for tumour therapy.


Asunto(s)
Diferenciación Celular/inmunología , Células Dendríticas/citología , Células Endoteliales/citología , Neovascularización Patológica/metabolismo , Linaje de la Célula/inmunología , Células Cultivadas , Células Dendríticas/inmunología , Células Endoteliales/inmunología , Citometría de Flujo , Humanos , Inmunohistoquímica , Neoplasias/irrigación sanguínea , Oncostatina M/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo
5.
Bone Marrow Transplant ; 35(9): 915-20, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15778728

RESUMEN

Fludarabine is a nonmyeloablative immunosuppressant increasingly used as a component of alternative reduced-intensity conditioning regimens prior to allogeneic stem cell transplantation (SCT). However, we have previously shown that 2-fluoroadenine 9-beta-D-arabinofuranoside (F-Ara) as the active metabolized form of fludarabine induces damage, activation and allogenicity in human microvascular endothelial cells (HMEC). We had also identified the pharmaceutic compound Defibrotide (DF), originally used in the treatment of veno-occlusive disease and thrombotic microangiopathy, as being protective against F-Ara-induced dysfunction of HMEC, importantly, without affecting the antileukemic effect of F-Ara. In the present report, we show that a recently developed derivative of DF, Oligotide, similarly downregulates F-Ara-induced activation and damage of HMEC as well as their antigenicity for allogeneic CD8+ T cells. In addition, Oligotide could also block F-Ara-mediated transendothelial migration of peripheral blood cells across the HMEC barrier. Taken together, these observations argue for a potential clinical use of both DF and Oligotide in pre transplant conditioning.


Asunto(s)
Antineoplásicos/toxicidad , Células Endoteliales/metabolismo , Endotelio Vascular/fisiopatología , Oligodesoxirribonucleótidos/administración & dosificación , Acondicionamiento Pretrasplante , Vidarabina/análogos & derivados , Vidarabina/toxicidad , Línea Celular , Movimiento Celular/efectos de los fármacos , Endotelio Vascular/lesiones , Polidesoxirribonucleótidos , Acondicionamiento Pretrasplante/métodos , Enfermedades Vasculares/inducido químicamente , Enfermedades Vasculares/fisiopatología , Enfermedades Vasculares/prevención & control
6.
Reprod Biomed Online ; 7(5): 558-62, 2003 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-14680548

RESUMEN

The X-linked dominant form of Charcot-Marie-Tooth syndrome (CMTX) is a clinically and genetically heterogeneous hereditary disorder of the peripheral nerves caused by mutations in the GJB1 gene that encodes a gap junction protein named connexin 32 (Cx32). Clinically, CMTX is characterized by peripheral motor and sensory deficit with muscle atrophy. A couple with a previous history of pregnancy termination after being diagnosed positive for CMTX by chorionic villus sampling, was referred for preimplantation genetic diagnosis (PGD). The female partner carried the causative H94Q, characterized by a C-->G substitution in codon 94 of exon 2 of the GJB1 gene. Embryos obtained after intracytoplasmic sperm injection (ICSI) were evaluated for the presence of the mother's mutation using polymerase chain reaction (PCR), followed by mutation analysis performed using the minisequencing method. Amelogenin sequences on the X and Y chromosomes were also co-amplified to provide a correlation between embryo gender and mutation presence. A single PGD cycle was performed, involving nine fertilized oocytes, five of which developed into good quality embryos useful for biopsy. Two unaffected embryos were transferred, resulting in a singleton pregnancy followed by the birth of a healthy female.


Asunto(s)
Enfermedad de Charcot-Marie-Tooth/diagnóstico , Enfermedad de Charcot-Marie-Tooth/genética , Cromosomas Humanos X , Diagnóstico Preimplantación , Adulto , Amelogenina , Conexinas/genética , Análisis Mutacional de ADN , Proteínas del Esmalte Dental/genética , Transferencia de Embrión , Femenino , Ligamiento Genético , Humanos , Masculino , Mutación , Reacción en Cadena de la Polimerasa , Inyecciones de Esperma Intracitoplasmáticas , Proteína beta1 de Unión Comunicante
7.
J Immunol ; 165(2): 860-8, 2000 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-10878360

RESUMEN

IL-2 is the major autocrine and paracrine growth factor produced by T cells upon T cell stimulation. The inducible expression of IL-2 is highly regulated by multiple transcription factors, particularly AP-1, which coordinately activate the promoter. Described here is the ability of the novel basic leucine zipper protein p21SNFT to repress AP-1 activity and IL-2 transcription. A detailed analysis of the repression by p21SNFT repression on the IL-2 promoter distal NF-AT/AP-1 site demonstrates that it can bind DNA with NF-AT and Jun, strongly suggesting that it represses NF-AT/AP-1 activity by competing with Fos proteins for Jun dimerization. The importance of this repression is that p21SNFT inhibits the trans-activation potential of protein complexes that contain Jun, thereby demonstrating an additional level of control for the highly regulated, ubiquitous AP-1 transcription factor and the IL-2 gene.


Asunto(s)
Interleucina-2/antagonistas & inhibidores , Interleucina-2/genética , Leucina Zippers/inmunología , Proteínas Nucleares , Regiones Promotoras Genéticas/inmunología , Proteínas Represoras/fisiología , Factores de Transcripción/fisiología , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico , Sitios de Unión/genética , Sitios de Unión/inmunología , Proteínas de Unión al ADN/metabolismo , Regulación hacia Abajo/inmunología , Regulación de la Expresión Génica/inmunología , Humanos , Células Jurkat/inmunología , Células Jurkat/metabolismo , Leucina Zippers/genética , Activación de Linfocitos/genética , Sustancias Macromoleculares , Datos de Secuencia Molecular , Peso Molecular , Factores de Transcripción NFATC , Proteínas Proto-Oncogénicas c-jun/metabolismo , Proteínas Represoras/biosíntesis , Proteínas Represoras/metabolismo , Factor de Transcripción AP-1/metabolismo , Factores de Transcripción/biosíntesis , Factores de Transcripción/metabolismo , Transfección/inmunología
8.
Br J Haematol ; 111(4): 1122-9, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11167751

RESUMEN

Severe hepatic veno-occlusive disease (VOD) is a recognized complication of autologous and allogeneic stem cell transplantation (SCT) that is often fatal. Defibrotide (DF) is a polydeoxyribonucleotide that has been found to have anti-thrombotic, anti-ischaemic and thrombolytic properties without causing significant anticoagulation. Preliminary studies have demonstrated activity for DF in the treatment of VOD, with minimal associated toxicity. In the present study, 40 patients who fulfilled established criteria for VOD were treated with DF on compassionate grounds in 19 European centres; 28 patients met risk criteria predicting progression of VOD and fatality or had evidence of multiorgan failure (MOF), and were defined as 'poor-risk'. DF was commenced intravenously at a median of 14 d (range, -2 d to 53 d) post SCT at doses ranging from 10 to 40 mg/kg. The median duration of therapy was 18 d (range, 2--71 d). Twenty-two patients showed a complete response (CR) (bilirubin < 34.2 micromol/l and resolution of signs/symptoms of VOD and end-organ dysfunction) [CR = 55%, confidence interval (CI) 40--70%] and 17 patients (43%) are alive beyond d +100. Ten poor-risk patients showed a complete response (CR = 36%, CI 21--51%). These results demonstrate that DF is an active treatment for VOD following SCT and a randomized trial is now underway in order to further evaluate its role.


Asunto(s)
Fibrinolíticos/uso terapéutico , Trasplante de Células Madre Hematopoyéticas , Enfermedad Veno-Oclusiva Hepática/tratamiento farmacológico , Polidesoxirribonucleótidos/uso terapéutico , Complicaciones Posoperatorias/tratamiento farmacológico , Enfermedad Aguda , Adolescente , Adulto , Bilirrubina/análisis , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/cirugía , Niño , Preescolar , Femenino , Enfermedad Veno-Oclusiva Hepática/sangre , Enfermedad de Hodgkin/tratamiento farmacológico , Enfermedad de Hodgkin/cirugía , Humanos , Lactante , Leucemia Mieloide/tratamiento farmacológico , Leucemia Mieloide/cirugía , Masculino , Persona de Mediana Edad , Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/cirugía , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/cirugía , Resultado del Tratamiento
9.
Blood ; 92(3): 737-44, 1998 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-9680339

RESUMEN

Hepatic veno-occlusive disease (VOD) is the most common of the regimen-related toxicities accompanying stem cell transplantation (SCT). Despite aggressive therapies, including the combination of tissue plasminogen activator (t-PA) and heparin, severe VOD is almost uniformly fatal. Defibrotide (DF) is a polydeoxyribonucleotide with activity in several vascular disorders and, unlike t-PA and heparin, produces no systemic anticoagulant effects. Nineteen patients who developed severe VOD after SCT were treated with DF on a compassionate-use basis. Patients had clinically established VOD and met risk criteria predicting progression and fatality. At the initiation of DF, all 19 patients had evidence of multiorgan dysfunction; median bilirubin was 22.3 mg/dL, 12 patients had renal insufficiency (5 dialysis dependent), 14 required oxygen supplementation, and encephalopathy was present in 8 patients. Beginning a median of 6 days after diagnosis of VOD, DF was administered intravenously in doses ranging from 5 to 60 mg/kg/d for a planned minimum course of 14 days. In no case was DF discontinued for attributable toxicity. No severe hemorrhage related to DF administration was observed. Resolution of VOD (bilirubin <2 mg/dL with improvement in other symptoms and signs) was seen in 8 patients (42%). Six of 8 responders survived past day +100, contrasted with the 2% predicted survival reported in comparable patients. The observed response rate, survival to day +100, and absence of significant DF treatment-associated toxicity are compelling and warrant further evaluation.


Asunto(s)
Fibrinolíticos/uso terapéutico , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Enfermedad Veno-Oclusiva Hepática/tratamiento farmacológico , Polidesoxirribonucleótidos/uso terapéutico , Adolescente , Adulto , Bilirrubina/sangre , Niño , Preescolar , Evaluación de Medicamentos , Estudios de Factibilidad , Femenino , Fibrinolíticos/efectos adversos , Hemorragia/inducido químicamente , Heparina/uso terapéutico , Enfermedad Veno-Oclusiva Hepática/mortalidad , Humanos , Masculino , Insuficiencia Multiorgánica/prevención & control , Neoplasias/mortalidad , Neoplasias/terapia , Cuidados Paliativos , Polidesoxirribonucleótidos/efectos adversos , Receptores Purinérgicos P1/efectos de los fármacos , Estudios Retrospectivos , Riesgo , Talasemia/terapia , Activador de Tejido Plasminógeno/uso terapéutico , Resultado del Tratamiento
10.
J Immunol ; 159(3): 1319-27, 1997 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-9233628

RESUMEN

CD28 is an important costimulatory molecule in the activation of human T cells. Costimulation of T cells through both the Ag receptor and CD28 leads to high level IL-2 production, which is vital to the development of an immune response in vivo. Previous reports have suggested the CD28 stimulation contributes to the activation of the IL-2 promoter by up-regulating the activity of several transcription factors, including AP-1 and nuclear factor-kappaB (NF-kappaB)/Rel family members as well as an uncharacterized transcription factor called CD28 response complex. While several lines of investigation have suggested that NF-kappaB/Rel family members make up the CD28 response complex transcription factor, other work has not supported this conclusion. Recent studies suggest that the CD28 response element (CD28RE) does not function independently but works instead in conjunction with the adjacent promoter proximal AP-1-binding site and this hypothesis is confirmed here. Also in the current study, binding activity to the CD28RE/AP-1 sequence of the IL-2 promoter is evaluated. Although four specific complexes can be detected binding to this sequence, only one of these complexes is specific for both the CD28RE and the adjacent AP-1 site. Of the NF-kappaB/Rel family members tested, this CD28RE/AP-1-specific complex contains predominantly c-Rel, despite the fact that both p50 and RelA can efficiently bind to the CD28RE. c-Fos and c-Jun are also found in this CD28RE/AP-1-specific complex. These data indicate that functional complexes encompassing both the CD28RE and the AP-1-binding sites influence IL-2 promoter activity in CD28-costimulated T cells.


Asunto(s)
Antígenos CD28/genética , Proteínas de Unión al ADN/genética , Interleucina-2/genética , Regiones Promotoras Genéticas/inmunología , Linfocitos T/metabolismo , Factor de Transcripción AP-1/genética , Antígenos CD28/metabolismo , Proteínas de Unión al ADN/metabolismo , Electroforesis en Gel de Poliacrilamida , Humanos , Interleucina-2/metabolismo , Células Jurkat , Activación de Linfocitos/genética , FN-kappa B/genética , FN-kappa B/metabolismo , Proteínas Proto-Oncogénicas c-fos/genética , Proteínas Proto-Oncogénicas c-fos/metabolismo , Proteínas Proto-Oncogénicas c-jun/genética , Proteínas Proto-Oncogénicas c-jun/metabolismo , Linfocitos T/inmunología , Factor de Transcripción AP-1/metabolismo , Transfección
11.
Stomatol Mediterr ; 9(2): 107-9, 1989.
Artículo en Italiano | MEDLINE | ID: mdl-2639513

RESUMEN

The Authors present a modern treatment of the Recurrent Aphthous Ulcers (R.A.U.) with antibiotics, C vit. and intestinal flora as prophylaxis, with laser against pain and with cortisone to depress the immunitary origin of disease. They briefly analyze some clinical cases.


Asunto(s)
Estomatitis Aftosa/terapia , Antibacterianos/uso terapéutico , Ácido Ascórbico/uso terapéutico , Cortisona/uso terapéutico , Humanos , Terapia por Láser
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA