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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
In vitro and in vivo analysis of human cell-based immunotherapies for acute myeloid leukemia
Get PDFConventional cancer therapies like surgery, radiation and chemotherapy help to eliminate primary tumor masses but often fail to eradicate disseminated tumor cells. However, it is such residual tumor cells that frequently underlie metastasis and relapse. Major obstacles for targeting such cells are wide spread dissemination and long-term persistence in niches that are difficult to reach. For example, many patients with acute myeloid leukemia (AML) show persistence of leukemia after chemotherapy – so-called minimal residual disease (MRD) – which confers a life-threatening risk for relapse in over 70% of patients. Arming the immune system to attack residual tumor cells has high therapeutic potential since immune cells can patrol the body to find and destroy residual tumor cells. Therapeutic approaches using the immune system - so-called immunotherapies - can take several forms. My project concentrated on preclinical studies of two strategies: 1) use of dendritic cells (DC) for therapeutic vaccination and 2) adoptive T cell therapy with lymphocytes expressing transgenic T cell receptors (TCR) specific for tumor-associated antigens (TAA).
In therapeutic vaccination a highly potent vaccine is needed to induce a valid immune response in patients with cancer. Effective antitumor immunity requires mobilization of IFN-γ-producing CD4+ T cells (Th1 cells) and lymphocytes with cytotoxic function, including cytotoxic T lymphocytes (CTL) and natural killer (NK) cells. In my studies, high potency vaccines were developed using mature DC generated in 3 days (3d-mDC) that were stimulated with synthetic Toll-like receptor TLR3 and/or TLR7/8 agonists. This TLR stimulation mimics DC interaction with viruses and causes mDC to secrete the bioactive form of IL-12, supporting induction of effector cells. Characterization in vitro showed that TLR-activated 3d-mDC were superior to conventional 7d-mDC in capacity to induce Th1 cells as well as CTL. A humanized mouse model was established to verify these observations in vivo. NOD/scid IL2Rgnull mice, lacking murine T, B and NK cells, were reconstituted with human peripheral mononuclear cells and vaccinated with 3d-mDC, stimulated or not with TLR agonists, and conventional 7d-mDC. Induction of CTL was quantified ex vivo using splenocyte populations containing human lymphocytes. The in vivo results were concordant with in vitro observations, demonstrating the superior capacity of 3d-mDC that were stimulated with TLR agonists to induce CTL.
Adoptive T cell therapy using TCR-modified lymphocytes represents a second powerful way to provide patients with specific antitumor immunity. Here previously isolated TCR gene sequences are introduced into activated patient-derived lymphocytes, assigning them new antigen specificities. First, T cells must be isolated with TAA specificities that express high-affinity TCR which effectively recognize tumor cells. It was contended that T cell stimulation using peptide-epitopes from TAA presented on foreign MHC would allow isolation of high-affinity TCR, since these T cells had not yet undergone negative selection in the thymus. This contention was proved in individual experiments, as described in this thesis, for the antigens tyrosinase, survivin and HMMR (hyaluronan-mediated motility receptor). Since survivin and HMMR are broadly expressed in AML, TCR specific for these TAA were isolated and subsequently transferred into recipient lymphocytes. Expression of survivin-specific TCR resulted in MHC-restricted death of transduced lymphocytes due to their elevated survivin expression after activation. This precludes use of survivin-specific TCR for therapy of AML.
In contrast, transfer of an HMMR-specific TCR yielded effector lymphocytes that effectively killed AML cells in vitro. The behavior in vivo of TCR transduced lymphocytes is crucial for therapeutic outcome. To explore this capacity a xenograft mouse model was established using solid and disseminated human tumor cells injected into NOD/scid IL2Rgnull mice. Adoptive transfer of lymphocytes expressing an HMMR-specific TCR into tumor-bearing mice resulted in significant retardation of tumor outgrowth. Adoptive transfer of memory-like lymphocytes with higher proliferative potential and prolonged in vivo survival may also affect tumor growth. Analyses in vivo and in vitro showed that IL-15-induced effector memory T cells conferred the most potent antitumor immunity.
In summary, this work provides evidence for potent in vivo antitumor effects by either using DC-based vaccines or adoptive transfer of TCR transduced lymphocytes, opening application of both strategies for immunotherapy of cancer
Insights from immuno-oncology: the Society for Immunotherapy of Cancer Statement on access to IL-6-targeting therapies for COVID-19
No full textThe hypoxia and profound inflammatory response associated with the pneumonitis observed with the SARS-CoV-2 virus responsible for the recent COVID-19 pandemic has overwhelmed intensive care facilities in the epicenters of infection including Wuhan, China, Northern Italy and in the USA, the Seattle and New York City areas. The Society for Immunotherapy of Cancer (SITC) stands along with and supports our colleagues in emergency departments, intensive care units (ICUs) and inpatient wards in the global effort to overcome this unprecedented pandemic. ©202
Impact of oncogenic pathways on evasion of antitumour immune responses
No full textImmunotherapeutic interventions are showing effectiveness across a wide range of cancer types, but only a subset of patients shows clinical response to therapy. Responsiveness to checkpoint blockade immunotherapy is favoured by the presence of a local, CD8⁺ T cell-based immune response within the tumour microenvironment. As molecular analyses of tumours containing or lacking a productive CD8⁺ T cell infiltrate are being pursued, increasing evidence is indicating that activation of oncogenic pathways in tumour cells can impair induction or execution of a local antitumour immune response. This Review summarizes our current knowledge of the influence of oncogenic effects on evasion of antitumour immunity.National Cancer Institute (U.S.) (Grant K99/R00CA204595
WNT Signaling in Cancer Immunosurveillance
No full textDeregulated WNT signaling has been shown to favor malignant transformation, tumor progression, and resistance to conventional cancer therapy in a variety of preclinical and clinical settings. Accumulating evidence suggests that aberrant WNT signaling may also subvert cancer immunosurveillance, hence promoting immunoevasion and resistance to multiple immunotherapeutics, including immune checkpoint blockers. Here, we discuss the molecular and cellular mechanisms through which WNT signaling influences cancer immunosurveillance and present potential therapeutic avenues to harness currently available WNT modulators for cancer immunotherapy.National Cancer Institute (U.S.) (Award R00CA204595
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