Publications by authors named "Martinez-Lorenzo M"

Traditionally, when antibody to the Hepatitis B core antigen (anti-HBc) and antibody to the Hepatitis B surface antigen (anti-HBs) are positive, the donor is considered suitable. However, the literature contains cases with this profile and circulating hepatitis B virus DNA. The aim of the study is to analyze the incidence of occult hepatitis B virus infection (OBI).

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Background: The need for high-cellular-content cord blood units (CBUs) for allogenic transplantation is evident to improve clinical outcomes. In our environment and with current donation programs, very few collected units meet suggested clinical thresholds, making collection programs highly inefficient. To increase the clinical conversion rate, we have assessed factors influencing the cellular content of the cord blood collection and established the estimated fetal weight percentile (EFWp) as a tool to predict which deliveries will obtain higher cellular counts.

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It is widely agreed that the best source of nutrition for the newborn is the milk of their own mothers. In those cases where it is not available, especially in very premature and/or very low birth weight infants, as well as other sick newborns, the preferred choice before formula is the human milk provided by selected donors. This indication is supported by the highest international bodies dedicated to the health of the child population, including the World Health Organisation as well as the main national and international scientific societies in the field of Paediatrics.

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Treponema pallidum infections can have severe complications if not diagnosed and treated at an early stage. Screening and diagnosis of syphilis require assays with high specificity and sensitivity. The Elecsys Syphilis assay is an automated treponemal immunoassay for the detection of antibodies against T.

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Mesenchymal stem cells (MSCs) are self-renewing, multipotent cells that could potentially be used to repair injured cartilage in diseases such as osteoarthritis (OA). In this study we used bone marrow, adipose tissue from articular and subcutaneous locations, and synovial fluid samples from 18 patients with knee OA to find a suitable alternative source for the isolation of MSCs with high chondrogenic potential. MSCs from all tissues analysed had a fibroblastic morphology, but their rates of proliferation varied.

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Drugs containing the quinone group were tested on hyperproliferative leukemia T cells (HLTC: Jhp and Jws) and parental Jurkat cells. Doxorubicin, menadione and adaphostin produced different effects on these cell lines. Rapid doxorubicin-induced cell death in Jurkat cells was mediated by caspase activation.

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Objective: We previously observed that T lymphocytes present in synovial fluid (SF) from patients with rheumatoid arthritis (RA) were sensitive to APO2L/TRAIL. In addition, there was a drastic decrease in the amount of bioactive APO2L/TRAIL associated with exosomes in SF from RA patients. This study was undertaken to evaluate the effectiveness of bioactive APO2L/TRAIL conjugated with artificial lipid vesicles resembling natural exosomes as a treatment in a rabbit model of antigen-induced arthritis (AIA).

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This study analyzed the phenotype and the chondrogenic differentiation of bone marrow-derived MSCs from old patients undergoing knee osteoarthritis or femoral fracture surgery. Twenty patients (12 females), with a mean age of 77.35±8.

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Mesenchymal stem cells (MSCs) are multipotent cells capable of differentiating into several mesoderm lineages. They have been isolated from different tissues, such as bone marrow, adult peripheral blood, umbilical cord blood, and adipose tissue. The aim of this study was to analyze the differences in proliferation and phenotype of adipose tissue-derived MSCs from three different species, and to evaluate their capacity to differentiate into chondrocytes in vitro.

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Article Synopsis
  • PSAP, a protein initially identified for interacting with presenilin 1, is a mitochondrial protein that can induce cell death (apoptosis) when overexpressed.
  • The study identifies two isoforms of PSAP generated through alternative splicing, which differ in a specific hydrophilic loop between transmembrane domains and are found in various human and rat tissues.
  • Results suggest that PSAP is vital for mitochondrial function, as specific transmembrane domains are necessary for its proper mitochondrial localization and proapoptotic activity.
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A need for factors predictive of prognosis is present in patients who are diagnosed with malignant melanoma. The detection of circulating melanoma cells by reverse transcriptase-polymerase chain reaction for tyrosinase mRNA is a possible negative prognostic factor. The aim of this study was to assess the prognostic value of reverse transcriptase-PCR for tyrosinase mRNA in peripheral blood samples.

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The improved recombinant form of the death ligand Apo2L/TRAIL (Apo2L/TRAIL.0) is not cytotoxic for normal human cells and is a good candidate for the therapy of multiple myeloma (MM), a B-cell neoplasia that remains incurable. We have analyzed the molecular determinants of myeloma sensitivity to Apo2L/TRAIL.

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Apo2L/TRAIL is a member of the TNF family, with its receptors DR4 and DR5 containing a death domain. Multiple tumors are sensitive to Apo2L/TRAIL-induced apoptosis, while normal cells are not, so it constitutes a promising new antitumoral therapy. In this review we deal rather with the physiological role of Apo2L/TRAIL, which, in one hand, is clearly related with immune antitumoral surveillance.

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Specificity problems, especially in immunoblot analysis, have been shown for several commercial antibodies raised against the death ligand Fas ligand (FasL) using conventional protein and/or peptide immunizations. In this work, we have optimized the development of rabbit antisera and isolated pAb against the death ligands FasL, Apo2 ligand/TRAIL and Apo3 ligand/TWEAK by cDNA intramuscular immunization. This alternative approach has generated specific pAb in all three cases, which are useful for immunoblot purposes.

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The infiltration and accumulation of T cells in the rheumatoid arthritis (RA) synovial fluid (SF) are hallmarks of disease. We aimed to assess the functional relevance of FasL and of APO2L/TRAIL in the persistence of T cells in the rheumatoid SF. We have analyzed the expression of the activation markers HLA-DR and CD69 and also of the death receptor Fas/CD95 and death ligands FasL or APO2L/TRAIL in CD3+ lymphocytes from SF of 62 RA patients, together with their sensitivity to anti-Fas mAb or to rAPO2L/TRAIL, using as controls T lymphocytes present in SF of 20 patients with traumatic arthritis.

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Tendon xanthomas (TX) are pathognomonic lipid deposits commonly found in familial hypercholesterolemia (FH) patients. The aim of this study was to determine whether macrophages from FH patients with TX (TX+) have higher predisposition to foam cells formation after oxidized LDL (oxLDL) overload than those from FH patients without TX (TX-), and if their differential gene expression profile could explain these different phenotypes. Total RNA pools from macrophages from FH patients TX+ and TX- were analyzed using Affymetrix oligonucleotide arrays to evaluate the gene expression profile in presence and absence of oxLDL.

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The mechanisms responsible for the down-modulation of the activation of separated CD4(+) or CD8(+) human T cell blasts were studied using cells obtained from healthy donors. In the presence of IL-2, human CD8(+) T cell blasts were more sensitive than CD4(+) T cell blasts to regulation by APO2 ligand/TNF-related apoptosis-inducing ligand (APO2L/TRAIL), while both T cell subsets were equally sensitive to Fas/CD95 regulation. This regulation was defined as inhibition of IL-2-dependent T cell growth in the absence of cell death induction, characterized by cell cycle arrest in G(2)/M.

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A systematic study was undertaken to characterize the role of APO 2 ligand/tumor necrosis factor-related apoptosis-inducing ligand (APO2L/TRAIL) and Fas ligand (FasL) together with the expression of several anti- or proapoptotic proteins in the down-regulation of normal human T cell responses. We have observed for the first time that the higher sensitivity of normal human T cell blasts to apoptosis and activation-induced cell death (AICD) as compared with naive T cells correlates with the increased expression of Bcl-x short (Bcl-xS) and Bim. T cell blasts die in the absence of interleukin 2 (IL-2) with no additional effect of death receptor ligation.

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Tumor cells have developed multiple mechanisms to evade control by the immune system. Tumoral cells expressing Fas ligand (FasL) have been proposed to "counterattack" against activated antitumoral effector immune cells, although some authors have indicated that FasL is not expressed on the surface of the same tumors, such in the case of melanoma cells. However, other factors could be implicated, such as the balance of soluble versus membrane-bound forms or the secretion of death ligands on the surface of microvesicles, as described previously by our group in human T cells.

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CD8(+) cytotoxic T lymphocyte (CTL) clones are able to exert both perforin- and Fas-dependent cytotoxicity. We show in the present work that phosphatidylinositol 3-kinase (PI3K) inhibitors wortmannin and LY294002 prevent TCR/CD3-induced functional Fas ligand (FasL) expression, but not perforin-dependent cytotoxicity. The specific inhibitor of classical protein kinase C (PKC) isoforms, Gö6976, completely inhibited perforin-dependent cytotoxicity and only affected slightly TCR/CD3-induced FasL expression, while the opposite was observed using rottlerin, an inhibitor with higher specificity for PKCtheta.

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Fas/CD95 is a type-I membrane glycoprotein, which inducesapoptotic cell death when ligated by its physiological ligand. We generated previously hyperproliferative sublines derived from the human T-cell leukemia Jurkat, Jurkat-ws and Jurkat-hp, which lost Fas/CD95 surface expression. We have now observed that the total amount of Fas protein is similar in the sublines and in the parental cells, indicating that in the sublines Fas remains in an intracellular compartment.

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Preformed Fas ligand (FasL) and APO2 ligand (APO2L)/TNF-related apoptosis-inducing ligand (TRAIL) are stored in the cytoplasm of the human Jurkat T cell line and of normal human T cell blasts. The rapid release of these molecules in their bioactive form is involved in activation-induced cell death. In this study, we show by confocal microscopy that FasL and APO2L/TRAIL are mainly localized in lysosomal-like compartments in these cells.

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Maturation and maintenance of the intracellular vacuole in which Salmonella replicates is controlled by virulence proteins including the type III secretion system encoded by Salmonella pathogenicity island 2 (SPI-2). Here, we show that, several hours after bacterial uptake into different host cell types, Salmonella induces the formation of an F-actin meshwork around bacterial vacuoles. This structure is assembled de novo from the cellular G-actin pool in close proximity to the Salmonella vacuolar membrane.

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After uptake by host cells, the pathogen Brucella transits through early endosomes, evades phago-lysosome fusion and replicates in a compartment associated with the endoplasmic reticulum (ER). The molecular mechanisms underlying these processes are still poorly understood. To identify new bacterial factors involved in these processes, a library of 1800 Brucella melitensis 16M mini-Tn5catkm mutants was screened for intracellular survival and multiplication in HeLa cells and J774A.

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Salmonella spp. are enterobacteria capable of invading and replicating in both professional and non-professional phagocytes. Here, we investigate the fate of S.

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