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1.
Astron Astrophys ; 6452021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33408420

RESUMO

CONTEXT: Yebes 40m radio telescope is the main and largest observing instrument at Yebes Observatory and it is devoted to Very Long Baseline Interferometry (VLBI) and single dish observations since 2010. It has been covering frequency bands between 2 GHz and 90 GHz in discontinuous and narrow windows in most of the cases, to match the current needs of the European VLBI Network (EVN) and the Global Millimeter VLBI Array (GMVA). AIMS: Nanocosmos project, a European Union funded synergy grant, opened the possibility to increase the instantaneous frequency coverage to observe many molecular transitions with single tunnings in single dish mode. This reduces the observing time and maximises the output from the telescope. METHODS: We present the technical specifications of the recently installed 31.5 - 50GHz (Q band) and 72 - 90.5 GHz (W band) receivers along with the main characteristics of the telescope at these frequency ranges. We have observed IRC+10216, CRL 2688 and CRL 618, which harbour a rich molecular chemistry, to demonstrate the capabilities of the new instrumentation for spectral observations in single dish mode. RESULTS: The results show the high sensitivity of the telescope in the Q band. The spectrum of IRC+10126 offers a signal to noise ratio never seen before for this source in this band. On the other hand, the spectrum normalised by the continuum flux towards CRL 618 in the W band demonstrates that the 40 m radio telescope produces comparable results to those from the IRAM 30 m radio telescope, although with a smaller sensitivity. The new receivers fulfil one of the main goals of Nanocosmos and open the possibility to study the spectrum of different astrophysical media with unprecedented sensitivity.

2.
Bone Marrow Transplant ; 55(4): 811-817, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31690809

RESUMO

Although many experts position statements on autologous stem cell mobilization have been published, there are some aspects that are still under discussion. A Spanish Hematologist expert group was summoned to settle on agreements and uncertainties on PBSCs mobilization, including factors not always considered; as apheresis and cytometry key factors that determine a successful PBSC collection. This document reviews critical factors that define poor mobilizer patients and the tools to better collect the desired stem cells for a successful autologous haematopoietic stem cell transplant.


Assuntos
Remoção de Componentes Sanguíneos , Células-Tronco de Sangue Periférico , Consenso , Mobilização de Células-Tronco Hematopoéticas , Humanos , Transplante Autólogo
3.
Ann Hematol ; 96(8): 1323-1330, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28536895

RESUMO

Guidelines recommend autologous stem cell transplantation (ASCT) consolidation in first complete or partial response after regimens including rituximab (R) and high-dose AraC (HDAC), but its use beyond that response is questioned. We present a retrospective analysis of 268 patients with MCL who received ASCT. With a median follow-up for survival patients of 54 months, progression-free survival and overall survival for the whole series were 38 and 74 months, respectively, and for patients transplanted in first CR 49 and 97 months, respectively. Patients without CR before transplant were analyzed separately, those who achieved CR after transplantation had better PFS (48 vs 0.03 months, p < 0.001) and OS (92 vs 16 months, p < 0.001) than the remaining. In univariate analysis, first CR at transplant (p = 0.01) and prior rituximab (p = 0.02) were the variables associated with PFS. For OS, the same variables resulted significant (p = 0.03 and p < 0.001, respectively). In multivariate analysis, only the status at transplant (first CR) remained significant. This retrospective study concludes that ASCT consolidation in first CR induces high survival rates. In other stages of disease, the need of ASCT as consolidation may be questioned.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Transplante de Células-Tronco Hematopoéticas/métodos , Linfoma de Célula do Manto/terapia , Adulto , Idoso , Citarabina/administração & dosagem , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Avaliação de Resultados em Cuidados de Saúde/métodos , Avaliação de Resultados em Cuidados de Saúde/estatística & dados numéricos , Modelos de Riscos Proporcionais , Indução de Remissão , Estudos Retrospectivos , Rituximab/administração & dosagem , Condicionamento Pré-Transplante , Transplante Autólogo , Adulto Jovem
4.
Cell Death Differ ; 19(5): 743-55, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22139129

RESUMO

Expansion of human stem cells before cell therapy is typically performed at 20% O(2). Growth in these pro-oxidative conditions can lead to oxidative stress and genetic instability. Here, we demonstrate that culture of human mesenchymal stem cells at lower, physiological O(2) concentrations significantly increases lifespan, limiting oxidative stress, DNA damage, telomere shortening and chromosomal aberrations. Our gene expression and bioenergetic data strongly suggest that growth at reduced oxygen tensions favors a natural metabolic state of increased glycolysis and reduced oxidative phosphorylation. We propose that this balance is disturbed at 20% O(2), resulting in abnormally increased levels of oxidative stress. These observations indicate that bioenergetic pathways are intertwined with the control of lifespan and decisively influence the genetic stability of human primary stem cells. We conclude that stem cells for human therapy should be grown under low oxygen conditions to increase biosafety.


Assuntos
Técnicas de Cultura de Células/métodos , Glicólise/fisiologia , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Oxigênio/metabolismo , Aneuploidia , Células Cultivadas , Instabilidade Cromossômica/genética , Humanos , Fosforilação Oxidativa , Estresse Oxidativo/genética , Telômero/genética
5.
Cell Death Differ ; 18(6): 985-95, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21164520

RESUMO

In spite of the extensive potential of human mesenchymal stem cells (hMSCs) in cell therapy, little is known about the molecular mechanisms that regulate their therapeutic properties. We aimed to identify microRNAs (miRNAs) involved in controlling the transition between the resting and reparative phenotypes of hMSCs, hypothesizing that these miRNAs must be present in the undifferentiated cells and downregulated to allow initiation of distinct activation/differentiation programs. Differential miRNA expression analyses revealed that miR-335 is significantly downregulated upon hMSC differentiation. In addition, hMSCs derived from a variety of tissues express miR-335 at a higher level than human skin fibroblasts, and overexpression of miR-335 in hMSCs inhibited their proliferation and migration, as well as their osteogenic and adipogenic potential. Expression of miR-335 in hMSCs was upregulated by the canonical Wnt signaling pathway, a positive regulator of MSC self-renewal, and downregulated by interferon-γ (IFN-γ), a pro-inflammatory cytokine that has an important role in activating the immunomodulatory properties of hMSCs. Differential gene expression analyses, in combination with computational searches, defined a cluster of 62 putative target genes for miR-335 in hMSCs. Western blot and 3'UTR reporter assays confirmed RUNX2 as a direct target of miR-335 in hMSCs. These results strongly suggest that miR-335 downregulation is critical for the acquisition of reparative MSC phenotypes.


Assuntos
Diferenciação Celular , Movimento Celular/fisiologia , Regulação da Expressão Gênica/fisiologia , Células-Tronco Mesenquimais/metabolismo , MicroRNAs/biossíntese , Transdução de Sinais/fisiologia , Regiões 3' não Traduzidas/fisiologia , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Células HEK293 , Humanos , Interferon gama/genética , Interferon gama/metabolismo , Células-Tronco Mesenquimais/citologia , MicroRNAs/genética , Proteínas Wnt/genética , Proteínas Wnt/metabolismo
7.
Rev Esp Med Nucl ; 26(3): 165-8, 2007.
Artigo em Espanhol | MEDLINE | ID: mdl-17524311

RESUMO

Positron Emission Tomography (PET) has become a very useful tool for monitoring Hodgkin's disease patients in the last years. When there is suspicion of disease persistence after treatment, this technique makes it possible to evaluate treatment activity of the residual lesions observed in the CT scan. Furthermore, due to the whole body study, new tumor sites, which very often change the therapeutic option, can be detected. We must take into account, however, that 18F-FDG is a very sensitive but not very specific tumor marker, since some inflammatory or infectious conditions may be associated to significant radiopharmaceutical uptakes. Thus, in order to increase specificity it is mandatory to correlate the PET information with the rest of the conventional imaging and clinical data and evolution of the patient. We present the case of a woman with Hodgkin's disease in which 18F-FDG PET was included in the follow-up. Both conditions, tumor and infection, were present in different times of the course. The integration of all the x-ray, clinical, laboratory and metabolic information allowed for a better and correct management of this patient.


Assuntos
Fluordesoxiglucose F18 , Doença de Hodgkin/diagnóstico por imagem , Pneumonia/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Imagem Corporal Total , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Bleomicina/administração & dosagem , Terapia Combinada , Dacarbazina/administração & dosagem , Diagnóstico Diferencial , Doxorrubicina/administração & dosagem , Feminino , Doença de Hodgkin/tratamento farmacológico , Doença de Hodgkin/patologia , Doença de Hodgkin/radioterapia , Humanos , Linfonodos/diagnóstico por imagem , Mecloretamina/administração & dosagem , Transplante de Células-Tronco de Sangue Periférico , Prednisona/administração & dosagem , Procarbazina/administração & dosagem , Recidiva , Tomografia Computadorizada por Raios X , Transplante Autólogo , Vimblastina/administração & dosagem , Vincristina/administração & dosagem
8.
Ann Oncol ; 18(4): 652-7, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17229774

RESUMO

BACKGROUND: Peripheral T-cell lymphoma (PTCL) is a heterogeneous group of aggressive lymphomas associated with poor prognosis with standard chemotherapy. Consolidation with autologous stem-cell transplantation (ASCT) may improve survival. We present 74 patients transplanted in first complete response (CR) from the Spanish Lymphoma and Autologous Transplantation Group cooperative group. PATIENTS AND METHODS: Median age was 46 years. Eighty-eight percent presented advanced (III-IV) Ann Arbor stage; 53% had B symptoms; 52% had high lactate dehydrogenase; 65% had two or three risk factors of the adjusted-International Prognostic Index; 58% presented a high Tumor score and in 14% more than two adverse factors of the Prognostic Index for peripheral T-cell lymphoma (PIT) were observed. RESULTS: With a median follow-up of 67 months from diagnosis, the 5-year overall survival (OS) was 68% and progression-free survival (PFS) reached 63%. The multivariate analysis showed that the only factor associated with a shorter OS and PFS was the presence of more than two risk factors from the PIT risk system. CONCLUSIONS: In a retrospective study with a prolonged follow-up, consolidation with ASCT in CR patients who had presented unfavorable prognostic factors at diagnosis substantially increased the OS and PFS when compared with conventional chemotherapy. The PIT risk system identified 14% of patients without benefit from ASCT consolidation. Thus, other innovative therapies are still necessary in certain cases.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Linfoma de Células T Periférico/terapia , Adolescente , Adulto , Idoso , Feminino , Humanos , Linfoma de Células T Periférico/mortalidade , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Transplante Autólogo
9.
Ann Oncol ; 16(4): 625-33, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15737986

RESUMO

PURPOSE: To analyse outcome and prognostic factors for overall survival (OS) and time to treatment failure (TTF) in 357 patients with Hodgkin's lymphoma (HL) undergoing an autologous stem cell transplantation (ASCT) after a first relapse and reported to the The Grupo Espanol de Linfomas/Trasplante Autologo de Medula Osea (GEL/TAMO) Cooperative Group. METHODS: Two hundred and twenty males and 137 females with a median age of 29 years were autografted in second remission (n=181), first sensitive relapse (n=148) and first resistant relapse (n=28). RESULTS: Five-year actuarial TTF and OS were of 49% +/- 3% and 57% +/- 3%. Advanced stage at diagnosis, complementary radiotherapy before ASCT, a short first complete response (CR) and detectable disease at ASCT adversely influenced TTF. Year of transplant < or =1995, bulky disease at diagnosis, a short first CR, detectable disease at ASCT and > or =1 extranodal areas involved at ASCT were adverse factors for OS. CONCLUSIONS: ASCT constitutes a therapeutic option for HL patients after a first relapse. Promising results are observed in patients with low tumour burden at diagnosis, autografted after a long CR and without detectable disease at ASCT. Innovative approaches should be pursued for patients with risk factors at relapse.


Assuntos
Doença de Hodgkin/diagnóstico , Doença de Hodgkin/terapia , Transplante de Células-Tronco/métodos , Adolescente , Adulto , Idoso , Criança , Feminino , Seguimentos , Doença de Hodgkin/prevenção & controle , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/prevenção & controle , Prognóstico , Transplante de Células-Tronco/estatística & dados numéricos , Tempo , Transplante Autólogo , Resultado do Tratamento
10.
Ann Oncol ; 15(10): 1504-9, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15367411

RESUMO

BACKGROUND: Here we evaluate the results of high-dose chemotherapy and autologous stem-cell transplantation (HDC/ASCT) in 114 patients included in the GEL/TAMO registry between January 1990 and December 1999 with diffuse large B-cell lymphoma who failed to achieve complete remission (CR) with front-line conventional chemotherapy. PATIENTS AND METHODS: Sixty-eight per cent had a partial response (PR) and 32% failed to respond to front-line therapy. At transplant, 35% were chemoresistant and 29% had two to three adjusted International Prognostic Index (a-IPI) risk factors. RESULTS: After HDC/ASCT, 57 (54%) of 105 patients evaluable for response achieved a CR, 16 (15%) a PR and 32 (30%) failed. Nine patients were not assessed for response because of early death due to toxicity. With a median follow-up of 29 months for alive patients, the survival at 5 years is 43%, with a disease-free survival for complete responders of 63%. The lethal toxicity was 8%. Multivariate analysis revealed a-IPI and chemoresistance to be predicting factors. CONCLUSIONS: Our results show that one-third of patients who do not obtain a CR to front-line chemotherapy may be cured of their disease with HDC/ASCT. However, most chemoresistant patients pretransplant failed this therapy. For this population, as well as for those who presented with adverse factors of the a-IPI, pretransplant novel therapeutic modalities need to be tested.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Transplante de Medula Óssea , Linfoma de Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Transplante de Células-Tronco de Sangue Periférico , Adolescente , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Intervalo Livre de Doença , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Linfoma de Células B/patologia , Linfoma Difuso de Grandes Células B/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Transplante Autólogo , Resultado do Tratamento
11.
Bone Marrow Transplant ; 33(3): 347-50, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14676783

RESUMO

Central venous catheters are frequently used in leukapheresis to provide high flow rates. The most common locations are the subclavian or jugular vein, but insertion-related complications and inadequate flow are frequent problems. Experience using femoral venous access is limited, because this has been discouraged due to the high incidence of infectious or thromboembolic complications. We evaluated the safety and efficacy of 108 short-term femoral venous dialysis catheters used for the collection of peripheral blood stem cells (PBSCs). All catheters were placed by a member of the dialysis unit, and they remained in situ for the days needed to reach the target number of CD34+cells. No prophylactic antibiotic or antithrombotic therapy was used. A total of 232 apheresis sessions was performed. The longest duration a catheter remained in situ was 5 days. Most of the patients finished the collection in one or two apheresis sessions. There were no thrombotic or infectious complications, and insertion-related complications or mechanical problems were minimal. Apheresis results were similar to those reported using subclavian or jugular venous access. The short-term use of femoral venous dialysis catheters appears safe and effective for PBSC collection, simplifying the procedure, improving patient comfort, and reducing cost.


Assuntos
Cateteres de Demora/normas , Leucaférese/métodos , Adolescente , Adulto , Idoso , Cateteres de Demora/efeitos adversos , Criança , Feminino , Veia Femoral , Neoplasias Hematológicas/terapia , Humanos , Incidência , Infecções , Leucaférese/instrumentação , Masculino , Pessoa de Meia-Idade , Transplante de Células-Tronco de Sangue Periférico , Estudos Retrospectivos , Trombose
12.
Ann Oncol ; 14(5): 745-51, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12702529

RESUMO

BACKGROUND: Patients with primary refractory Hodgkin's disease (PR-HD) have a dismal prognosis when treated with conventional salvage chemotherapy. We analyzed time to treatment failure (TTF), overall survival (OS) and clinical variables influencing the outcome in patients undergoing autologous stem cell transplantation (ASCT) for PR-HD and reported to the Grupo Español de Linfomas/Trasplante Autólogo de Médula Osea (GEL/TAMO). PATIENTS AND METHODS: Sixty-two patients, 41 males and 21 females with a median age of 27 years (range 13-55) were analyzed. Forty-two patients (68%) had advanced stage at diagnosis, 47 (76%) presented with B symptoms and 29 (47%) with a bulky mediastinal mass. Seventy-five percent of the patients had received more than one line of therapy before ASCT. Thirty-three patients received bone marrow as a source of hematopoietic progenitors, and 29 peripheral blood. Six patients were conditioned with high-dose chemotherapy plus total-body irradiation and 56 received chemotherapy-based protocols. RESULTS: One-year transplantation-related mortality was 14% [95% confidence interval (CI) 6% to 23%]. Response rate at 3 months after ASCT was 52% [complete remission in 21 patients (34%), partial remission in 11 patients (18%)]. Actuarial 5-year TTF and OS were 15% (95% CI 5% to 24%) and 26% (95% CI 13% to 39%), respectively. The presence of B symptoms at ASCT was the only adverse prognostic factor significantly influencing TTF [relative risk (RR) 1.75, 95% CI 0.92-3.35, P = 0.08]. The presence of B symptoms at diagnosis (RR 2.08, 95% CI 0.90-4.79, P = 0.08), MOPP-like regimens as first-line therapy (RR 3.84, 95% CI 1.69-9.09, P = 0.001), bulky disease at ASCT (RR 2.79, 95% CI 0.29-6.03, P = 0.009) and two or more lines of therapy before ASCT (RR 2.24, 95% CI 0.95-5.27, P = 0.06) adversely influenced OS. CONCLUSIONS: In our experience, although overall results of ASCT in PR-HD patients are poor, one-quarter of the patients remain alive at 5 years. Despite this, other therapeutic strategies should be investigated in this group of patients to improve the outcome.


Assuntos
Doença de Hodgkin/mortalidade , Doença de Hodgkin/terapia , Transplante de Células-Tronco/estatística & dados numéricos , Adolescente , Adulto , Intervalos de Confiança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Estatísticas não Paramétricas , Taxa de Sobrevida , Fatores de Tempo , Transplante Autólogo , Resultado do Tratamento
13.
Ann Oncol ; 14(1): 140-51, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12488306

RESUMO

BACKGROUND: The purpose of this study was to analyse the results and prognostic factors influencing overall survival (OS) and disease-free survival (DFS) in 452 patients diagnosed with diffuse large cell lymphomas (DLCL) treated with high-dose therapy (HDT) included in the Grupo Español de Linfomas/Trasplante Autólogo de Médula Osea (GEL-TAMO) Spanish registry. PATIENTS AND METHODS: At transplantation, median age was 42 years (range 15-73), 146 patients (32%) were transplanted in first complete remission (1st CR), 19% in second CR (2nd CR) and 47% had active disease: sensitive disease in 157 (35%) patients [95 were in first partial remission (1st PR) and 62 in second PR (2nd PR)] and refractory disease in 55 (12%) patients. Age-adjusted International Prognostic Index (IPI) was 2 or 3 in 51 patients (12%). Conditioning regimen consisted of BEAM (carmustine, etoposide, cytarabine and melphalan) in 39% of patients, BEAC (carmustine, etoposide, cytarabine and cyclophosphamide) in 33%, CBV (carmustine, etoposide and cyclophosphamide) in 10% and cyclophosphamide plus total body irradiation (TBI) in 12%. RESULTS: Estimated overall survival (OS) and disease-free survival (DFS) at 5 years were 53% and 43%, respectively. The transplant-related mortality was 11% (53 cases). By multivariate analysis three variables significantly influenced OS and DFS: number of protocols to reach 1st CR, disease status at transplant and TBI in the conditioning regimen. Age-adjusted IPI at transplantation also influenced OS. CONCLUSIONS: Prolonged OS and DFS can be achieved in patients with DLCL after HDT and our results suggest that the best line of chemotherapy should be used up-front in patients considered as candidates for HDT in order to obtain an early CR. Resistant patients are not good candidates for HDT and they should be offered newer strategies. Finally, polichemotherapy conditioning regimens offer better results compared with TBI.


Assuntos
Biomarcadores Tumorais/análise , Transplante de Células-Tronco Hematopoéticas , Linfoma Difuso de Grandes Células B/terapia , Condicionamento Pré-Transplante , Adolescente , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica , Carmustina , Terapia Combinada , Ciclofosfamida , Citarabina , Citocinas , Doxorrubicina , Etoposídeo , Feminino , Humanos , L-Lactato Desidrogenase/metabolismo , Linfoma Difuso de Grandes Células B/sangue , Linfoma Difuso de Grandes Células B/mortalidade , Masculino , Melfalan , Pessoa de Meia-Idade , Podofilotoxina , Prednisona , Prognóstico , Radioterapia Adjuvante , Indução de Remissão , Estudos Retrospectivos , Transplante Autólogo , Resultado do Tratamento , Vincristina
14.
J Virol ; 74(24): 11538-47, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11090151

RESUMO

To get insights into the role played by each of the influenza A virus polypeptides in morphogenesis and virus particle assembly, the generation of virus-like particles (VLPs) has been examined in COS-1 cell cultures expressing, from recombinant plasmids, different combinations of the viral structural proteins. The presence of VLPs was examined biochemically, following centrifugation of the supernatants collected from transfected cells through sucrose cushions and immunoblotting, and by electron-microscopic analysis. It is demonstrated that the matrix (M1) protein is the only viral component which is essential for VLP formation and that the viral ribonucleoproteins are not required for virus particle formation. It is also shown that the M1 protein, when expressed alone, assembles into virus-like budding particles, which are released in the culture medium, and that the recombinant M1 protein accumulates intracellularly, forming tubular structures. All these results are discussed with regard to the roles played by the virus polypeptides during virus assembly.


Assuntos
Vírus da Influenza A/fisiologia , Infecções por Orthomyxoviridae/virologia , Proteínas da Matriz Viral/fisiologia , Montagem de Vírus , Animais , Células COS , Vírus da Influenza A/ultraestrutura , Vírion/fisiologia , Vírion/ultraestrutura
15.
J Gen Virol ; 81(Pt 1): 135-42, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10640551

RESUMO

A systematic analysis was carried out to identify the amino acid signals that regulate the nucleo-cytoplasmic transport of the influenza A virus nucleoprotein (NP). The analysis involved determining the intracellular localization of eight deleted recombinant NP proteins and 14 chimeric proteins containing the green fluorescent protein fused to different NP fragments. In addition, the subcellular distribution of NP derivatives that contained specific substitutions at serine-3, which is the major phosphorylation site of the A/Victoria/3/75 NP, were analysed. From the results obtained, it is concluded that the NP contains three signals involved in nuclear accumulation and two regions that cause cytoplasmic accumulation of the fusion proteins. One of the karyophilic signals was located at the N terminus of the protein, and the data obtained suggest that the functionality of this signal can be modified by phosphorylation at serine-3. These findings are discussed in the context of the transport of influenza virus ribonucleoprotein complexes into and out of the nucleus.


Assuntos
Núcleo Celular/metabolismo , Citoplasma/metabolismo , Vírus da Influenza A/metabolismo , Nucleoproteínas , Sinais Direcionadores de Proteínas/metabolismo , Transdução de Sinais , Proteínas do Core Viral/metabolismo , Substituição de Aminoácidos , Animais , Transporte Biológico , Linhagem Celular , Núcleo Celular/virologia , Citoplasma/virologia , Técnica Indireta de Fluorescência para Anticorpo , Proteínas de Fluorescência Verde , Vírus da Influenza A/genética , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Proteínas do Nucleocapsídeo , Plasmídeos/genética , Coelhos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas do Core Viral/química , Proteínas do Core Viral/genética
16.
J Virol ; 73(2): 1186-94, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9882320

RESUMO

The influenza A virus nucleoprotein (NP) is a multifunctional polypeptide which plays a pivotal role in virus replication. To get information on the domains and specific residues involved in the different NP activities, we describe here the preparation and characterization of 20 influenza A virus mutant NPs. The mutations, mostly single-amino-acid substitutions, were introduced in a cDNA copy of the A/Victoria/3/75 NP gene and, in most cases, affected residues located in regions that were highly conserved across the NPs of influenza A, B, and C viruses. The mutant NPs were characterized (i) in vivo (cell culture) by analyzing their intracellular localization and their functionality in replication, transcription, and expression of model RNA templates; and (ii) in vitro by analyzing their RNA-binding and sedimentation properties. The results obtained allowed us to identify both a mutant protein that accumulated in the cytoplasm and mutations that altered the functionality and/or the oligomerization state of the NP polypeptide. Among the mutations that reduced the NP capability to express chloramphenicol acetyltransferase protein from a model viral RNA (vRNA) template, some displayed a temperature-sensitive phenotype. Interestingly, four mutant NPs, which showed a reduced functionality in synthesizing cRNA molecules from a vRNA template, were fully competent to reconstitute complementary ribonucleoproteins (cRNPs) capable of synthesizing vRNAs, which in turn yielded mRNA molecules. Based on the phenotype of these mutants and on previously published observations, it is proposed that these mutant NPs have a reduced capability to interact with the polymerase complex and that this NP-polymerase interaction is responsible for making vRNPs switch from mRNA to cRNA synthesis.


Assuntos
Vírus da Influenza A/genética , Nucleoproteínas/genética , RNA Viral/biossíntese , Proteínas de Ligação a RNA , Proteínas do Core Viral/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Células COS , Cloranfenicol O-Acetiltransferase/genética , Expressão Gênica , Humanos , Vírus da Influenza A/metabolismo , Líquido Intracelular , Dados de Sequência Molecular , Mutagênese , Proteínas do Nucleocapsídeo , Nucleoproteínas/metabolismo , RNA Viral/metabolismo , Proteínas do Core Viral/metabolismo
18.
J Heart Lung Transplant ; 14(5): 846-55, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-8800719

RESUMO

BACKGROUND: Histologic changes in cardiac allografts resulting from fibrosis or acute rejection can modify ventricular diastolic function and ventricular inflow characteristics. These abnormalities may be detected by color M-mode Doppler echocardiography which has been shown to be sensitive in assessing ventricular diastolic function. METHODS: Twelve cardiac allograft recipients were prospectively studied with serial color M-mode and single-gated Doppler echocardiography, as well as with endomyocardial biopsy, with a follow-up of approximately 10 weeks. The myocardial interstitial collagen content as evaluated by videodensitometry was compared with right and left ventricular late filling termination times measured in the absence of a severe episode of rejection. RESULTS: A positive and significant correlation was found between the collagen content and the corresponding right ventricular late filling termination time (r = 0.89, p < 0.0001), but no correlation was found with the left ventricular late filling termination time. Moreover, variations in collagen content and variations in right ventricular late filling termination time were also highly correlated (r = 0.91, p < 0.0001). In allograft recipients who had episodes of rejection of grade 3A or greater, both right and left ventricular late filling termination times were significantly increased during rejection. CONCLUSIONS: Measurements of right ventricular late filling termination time by color M-mode Doppler echocardiography performed in the absence of acute rejection can be use to monitor the evolution of interstitial collagen content in cardiac allografts. The early detection of abnormally prolonged late filling termination time could be followed by endomyocardial biopsy to confirm the histologic changes.


Assuntos
Colágeno/análise , Ecocardiografia Doppler em Cores , Transplante de Coração , Miocárdio/química , Função Ventricular Direita , Adulto , Idoso , Biópsia , Feminino , Fibrose , Rejeição de Enxerto/diagnóstico , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Miocárdio/patologia , Estudos Prospectivos , Função Ventricular Esquerda
19.
J Virol ; 69(6): 3799-806, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7745727

RESUMO

The influenza A virus nucleoprotein (NP) has been examined with regard to its RNA-binding characteristics. NP, purified from virions and devoid of RNA, bound synthetic RNAs in vitro and interacted with the ribonucleotide homopolymers poly(A), poly(G), poly(U), and poly(C) in a salt-dependent manner, showing higher binding affinity for polypyrimidine homopolymers. To map the NP regions involved in RNA binding, a series of deleted forms of the NP were prepared, and these truncated polypeptides were tested for their ability to bind poly(U) and poly(C) homopolymers linked to agarose beads. Proteins containing deletions at the N terminus of the NP molecule showed reduced RNA-binding activity, indicating that this part of the protein was required to bind RNA. To identify the NP region or regions which directly interact with RNA, proteins having the maltose-binding protein fused with various NP fragments were obtained and tested for binding to radioactively labeled RNAs in three different assays: (i) nitrocellulose filter binding assays, (ii) gel shift assays, and (iii) UV light-induced cross-linking experiments. A maltose-binding protein fusion containing the N-terminal 180 amino acids of NP behaved as an RNA-binding protein in the three assays, demonstrating that the N terminus of NP can directly interact with RNA. This NP region could be further subdivided into two smaller regions (amino acids 1 to 77 and 79 to 180) that also retained RNA-binding activity.


Assuntos
Vírus da Influenza A/metabolismo , Nucleoproteínas/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteínas do Core Viral/metabolismo , Sequência de Aminoácidos , Sequência de Bases , Sítios de Ligação , Proteínas de Transporte/metabolismo , Maltose/metabolismo , Proteínas Ligantes de Maltose , Dados de Sequência Molecular , Proteínas do Nucleocapsídeo , Nucleoproteínas/química , Nucleoproteínas/genética , Biossíntese de Proteínas , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/isolamento & purificação , Proteínas Recombinantes de Fusão/metabolismo , Homologia de Sequência de Aminoácidos , Proteínas do Core Viral/química , Proteínas do Core Viral/genética
20.
Arch Mal Coeur Vaiss ; 88(3): 345-52, 1995 Mar.
Artigo em Francês | MEDLINE | ID: mdl-7487288

RESUMO

Ruptured mitral chordae tendinae is a classical complication of myxomatous mitral valves or Barlow's syndrome. This complication is controversial in non-myxomatous mitral valve. Of 91 consecutive patients with mitral valve prolapse examined over an 18 months period by transthoracic and transesophageal echocardiography, 42 (18 women and 24 men) with an average age of 76 +/- 8 years (60-93 years) had ruptured mitral chordae tendinae. The thickness of the anterior mitral leaflet measured at the distal third of the valve by transesophageal echocardiography enabled the identification of two groups of patients; group I: > 3 mm (24 patients), average 4.8 +/- 0.8 mm and group II: < or = 3 mm (18 patients), average 2.6 +/- 0.3 mm. The diameter of the mitral ring and left atrium, the length of the anterior mitral leaflet, the left ventricular end diastolic dimensions and fractional shortening, were measured by transthoracic 2D echocardiography (mitral ring) and M mode (other parameters). Ruptured chordae were detected in only 13 cases (31%) by transthoracic echocardiography; 38% were asymptomatic and a chance finding at transesophageal echocardiography. No significant difference was observed between the two groups with respect to age, gender presence of hypertension, dimensions of the cardiac chambers, fractional shortening or localisation of the prolapse related to the ruptured chordae. Fifty-eight per cent of patients in group I were in NYHA functional classes 3-4 as compared to 16% in group II (p < 0.02). The size of the left atrium was significantly greater in group I, 51 +/- 8 mm vs 38 +/- 7 mm (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Cordas Tendinosas/lesões , Ecocardiografia Transesofagiana , Ruptura Cardíaca/diagnóstico por imagem , Prolapso da Valva Mitral/diagnóstico por imagem , Valva Mitral , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Cordas Tendinosas/diagnóstico por imagem , Ecocardiografia Doppler , Feminino , Ruptura Cardíaca/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência da Valva Mitral/diagnóstico por imagem , Insuficiência da Valva Mitral/etiologia , Prolapso da Valva Mitral/etiologia
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