1,720,970 research outputs found
PRESENCE OF HCV RNA IN SERUM OF ASYMPTOMATIC BLOOD-DONORS INVOLVED IN POSTTRANSFUSION HEPATITIS (PTH)
No full textTo study the causes of residual posttransfusion hepatitis, serum from implicated donors was tested by PCR for the presence of HCV RNA. Of 20 anti HCV negative donors, 4 were HCV RNA positive and thus, infective. The results suggest that higher-level investigations are necessary for prospective donors who present blood enzyme abnormalities or other questionable characteristics
HEPATITIS-B VIRUS SPECIFIC TRANSCRIPTS IN PERIPHERAL-BLOOD MONONUCLEAR-CELLS
No full textWe report on the analysis of HBV transcription in peripheral blood mononuclear cells of chronically infected patients by polymerase chain reaction amplification. Our results suggest that in these cells gene expression occurs either as pregenomic or subgenomic transcripts
Dual phosphoinositide 3-kinase/mammalian target of rapamycin blockade is an effective radiosensitizing strategy for the treatment of non-small cell lung cancer harboring K-RAS mutations.
No full textNon–small cell lung cancer (NSCLC) is a leading cause of cancer-related death worldwide. NSCLC often harbors onco- genic K-RAS mutations that lead to the aberrant activation of several intracellular networks including the phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway. Oncogenic K-RAS predicts poor prognosis and resistance to treatment with ionizing radiation (IR). Oncogenic K-Ras expression in the respiratory epitheli- um is sufficient to initiate NSCLC tumorigenesis, which requires the catalytic subunit of PI3K. Thus, effective inhibition of the PI3K signaling should lead to significant antitumor effects. However, therapy with rapamycin ana- logues has yielded disappointing results due in part to compensatory up-regulation of AKT. We hypothesized that dual PI3K/mTOR blockade would overcome these limita- tions. We tested this hypothesis with BEZ235, a novel dual PI3K/mTOR inhibitor that has recently entered clinical development. We found that BEZ235 induces a striking antiproliferative effect both in transgenic mice with oncogenic K-RAS–induced NSCLC and in NSCLC cell lines expressing oncogenic K-RAS. We determined that treatment with BEZ235 was not sufficient to induce apoptosis. However, we found that dual PI3K/mTOR blockade effectively sensitizes NSCLC expressing oncogenic K-RAS to the proapoptotic effects of IR both in vitro and in vivo. We conclude that dual PI3K/mTOR blockade in combination with IR may benefit patients with NSCLC expressing oncogenic K-RAS. These findings may have general applicability in cancer therapy, because aberrant activation of PI3K occurs frequently in human cancer
HCV RNA IN SERUM OF ASYMPTOMATIC BLOOD-DONORS INVOLVED IN POSTTRANSFUSION HEPATITIS (PTH)
No full textA group of blood donors involved in post-transfusion hepatitis was investigated for the presence of the anti-HCV antibody and of HCV RNA as a more direct infection marker. RNA was extracted from serum, reverse transcribed and amplified using primers which belonged to the non structural region. The amplified product of the PCR reaction was 582 base pairs. Seven (25.9%) of the 27 blood donors examined were found anti-HCV-positive by ELISA; five (71.4%) of these were HCV RNA positive. Among the 20 anti-HCV-negative blood donors, four (20.0%) were HCV RNA positive. ALT levels were below 45 UI/l in 18 donors, while the other nine had ALTs over the limit accepted for transfusion. The anti-HCV-negative HCV RNA-positive blood donors had normal ALTs. Our study offers a direct explanation for the substantial proportion of residual cases of anti-HCV-positive post-transfusion hepatitis and suggests the necessity of creating a register of blood donors who have at some time presented blood enzyme abnormalities and for whom second level investigations such as HCV RNA should be used
Hepatitis B virus infection of peripheral blood mononuclear cells is common in acute and chronic hepatitis.
No full textHepatitis B virus (HBV) infection of peripheral blood mononuclear cells (PBMCs) has been observed in all stages of liver disease. Thus far all information about the physical state of HBV in mononuclear blood cells comes from Southern blot analysis and in situ hybridization. In this study we focused our attention on the presence of HBV DNA sequences in PBMCs of 30 patients with acute type B hepatitis and 6 patients with chronic active hepatitis by utilizing both Southern blot analysis and the polymerase chain reaction (PCR). Southern blot analysis showed no HBV DNA sequences in PBMCs of the acute hepatitis patients, although the sensitivity of our method enabled us to detect as little as 1 pg of cloned HBV insert. As far as the chronic hepatitis patients are concerned Southern blot analysis revealed the presence of HBV DNA sequences in 5 out of 6 patients but intermittently at successive follow-up times. On the other hand we were able to demonstrate the presence of HBV related sequences in 14 out of 30 acute hepatitis patients (5 HBeAg positive, 9 antiHBe positive) and in all 6 chronic hepatitis patients by PCR. Our results indicate that the involvement of PBMCs with HBV during acute HBV infection occurs at a very low level, often below the detection limit of the Southern blot technique
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
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