1,720,978 research outputs found
Combination of low doses of Enzastaurin and Lenalidomide has synergistic activity in B-non-Hodgkin lymphoma cell lines
No full textLess toxic and more active treatments are needed for indolent lymphomas as there is no curative treatment, and patients eventually die due to complications related to their disease. The purpose of the present study was to assess the antitumour activity of the combination of low doses of Enzastaurin and Lenalidomide (Revlimid) on B-lymphoma cell lines. The combination of Enzastaurin and Lenalidomide, at doses as low as 1 μM, showed strong synergism against indolent lymphomas by reducing cell growth, producing an increase in G0-G1 phase followed by significant decrease in S phase, increasing apoptosis, and inhibiting PI3K/AKT, PKC and MAPK/ERK pathways. These preclinical findings, together with promising results obtained with Lenalidomide for the treatment of non-Hodgkin lymphoma, suggest that further evaluation of the combination of Enzastaurin and Lenalidomide for the treatment of indolent lymphomas is warranted. These compounds, with a favourable toxicity profile, are not classic chemotherapeutic agents, causing severe side effects, and could be considered an example of a new innovative attempt of an anti-cancer 'soft treatment'
Protective effect of acetyl-L-carnitine on oxidative damage induced by antiretroviral drugs
No full textBoth HIV infection per se and antiretroviral drugs might contribute to oxidative stress and mitochondrial dysfunctions. In this study we assess zidovudine, stavudine and didanosine on U937 and CEM cell lines. All these drugs induced apoptosis and increased intracellular hydrogen peroxide but not superoxide anions. The addition of acetyl-l-carnitine (ALC) was able to prevent the pro-oxidant effect of the drugs tested. Supplementation with ALC, deficient in certain cohorts of HIV-infected individuals, especially on high active antiretroviral therapy regimen, has been associated with favourable effects. These data suggest that one of these effects could be a direct anti-oxidant action
Characterization of cells with different mitochondrial membrane potential during apoptosis
No full textBackground: Until now, the simultaneous analysis of several parameters during apoptosis, including DNA content and mitochondrial membrane potential (Delta Psi), has not been possible because of the spectral characteristics of the commonly used dyes. Using polychromatic flow cytometry based upon multiple laser and UV lamp excitation, we have characterized cells with different Delta Psi during apoptosis. Methods: U937 cells were treated with the flavonoid quercetin (Qu) and stained with JC-1 to detect AT, propidium iodide (PI) for cell viability, Hoechst 33342 for DNA content, Annexin V conjugated with Alexa Fluor-647 for detection of phosphatidilserine (PS) exposure, marker of early apoptosis, or Mitotracker Deep Red for the determination of mitochondrial mass. Results: Treatment with Qu provoked the onset of three cell populations with different Delta Psi: (1) healthy cells, with normal Delta Psi, DNA content and physical parameters, high mitochondrial mass, PI- and Annexin V-negative; (2) cells with intermediate Delta Psi and normal DNA content, but with physical parameters typical of apoptotic cells and low mitochondrial mass; most of them were PI+ and Annexin V+; (3) cells with collapsed Delta Psi that had low mitochondrial mass and were Annexin-V+, PI+; half of them showed diminished DNA content. Similar results, i.e. the presence of cells with intermediate Delta Psi, were observed in other models of apoptosis. Conclusions: During Qu-induced apoptosis, loss of Delta Psi, PS exposure, and decrease of mitochondrial mass are early events that precede permeability to PI and loss of DNA. Populations of cells with different Delta Psi, as revealed by flow cytometry after JC-1 staining, differed also for other parameters associated to apoptosis. Thus, the simultaneous analysis of several parameters by polychromatic flow cytometry permits a better identification of many stages of cell death, and, more in general, allows to evaluate the eventual heterogenic sensibility of the population under study to a given compound
Modulation of CD38 expression in human longevity: A flow cytometric study
No full textThe dynamics of CD38 expression innewborns and young healthy donors hasbeen widely investigated for many years.However, little is known about the modulationof this marker during humanageing. We analyzed the changes inCD38 expression in peripheral bloodlymphocytes (PBL) from subjects whowere centenarians. For this purpose weused polychromatic flow cytometry, apowerful technology that allows the determinationof multiple antigens (in ourcase, up to 8) present in the same cell.Among the subsets within CD4+ andCD8+ T cell populations identified bythis approach, we investigated the expressionof CD38 together with markersrelated to extrathymic T cell differentiation(CD45RA and CCR7), T cell survival(CD127/IL-7rα) and activation/apoptosis(CD95). The groups analysed includedyoung donors (21±2 years old),middle-aged individuals (60±1.5 yearsold) and centenarians.By automatic boolean gating, we identifiedall the possible subsets obtained bythe combination of positive and negativeexpression for each marker indicatedabove. Moreover, we could distinguish betweendim or bright expression of CD38.CD38 expressed by CD4+ T cells doesnot show significant modifications in thethree samples either in of the virgin ormemory subsets.A slight increase in CD38 expressionwas found in PBL CD8+ T cells from centenarians.These CD8+/38dim T cells displayeda CD45RA-/CCR7+ central memoryor CD45RA-/CCR7- effector memoryphenotype. Further, CD38 expressionwas associated with the presence ofCD95 and the absence of CD127/IL-7rα.These results were also confirmed byCluster Analysis (CA) and PrincipalComponent Analysis (PCA) of the highnumber of T cell populations identifiedby flow cytometry. These bioinformatictechniques cluster the individuals accordingto the flow cytometric profile,which confirmed that the subsets with anincreased expression of CD38 (CD38bright) are more frequent in the sampleof centenarians.In conclusion, our data indicate amodulation of CD38 expression in CD8+T cells during human ageing. In particular,the preferential coexpression of thisantigen with CD95 but not CD127/IL-7r_suggests an age-dependent acquisition ofan effector phenotype of CD8+ T cellswhich could, at least in part, explain thechronic pro-inflammatory status presentin centenarians
The Role of Adjunctive Therapies in Septic Shock by Gram Negative MDR/XDR Infections
Full text linkPatients with septic shock by multidrug resistant microorganisms (MDR) are a specific sepsis population with a high mortality risk. The exposure to an initial inappropriate empiric antibiotic therapy has been considered responsible for the increased mortality, although other factors such as immune-paralysis seem to play a pivotal role. Therefore, beyond conventional early antibiotic therapy and fluid resuscitation, this population may benefit from the use of alternative strategies aimed at supporting the immune system. In this review we present an overview of the relationship between MDR infections and immune response and focus on the rationale and the clinical data available on the possible adjunctive immunotherapies, including blood purification techniques and different pharmacological approaches
T cell homeostasis in centenarians: from the thymus to the periphery.
No full textThe immune system undergoes a process of profound remodelling during aging, referred to as immunosenescence, and characterized by complex modifications of several components. In this review, we discuss recent developments and observations regarding the generation of T cells in the thymus during aging and longevity, and the regulation and maintenance of peripheral blood lymphocytes. The generation of new T cells is indeed crucial to maintain a functional immune system, and is a fundamental step to avoid unsuccessful aging, thus reaching longevity in good health. Mechanisms will be described that are related to the production and maintenance of those lymphocytes defined "recent thymic emigrants", and to the detection of the so called "T cell receptor rearrangement excision circles (TREC)", along with the presence in the periphery of naïve and memory T cells, that can be influenced and regulated by several different mechanisms. Several strategies aimed at improving thymic functionality are currently receiving a growing interest, and some of them are based on molecules that are produced by, and/or act on immune cells. Data on the possible use of these molecules, including cytokines like interleukin (IL)-7, IL-15 and keratinocyte growth factor, to restore thymic function are reviewed and discussed
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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