1,720,996 research outputs found
Platinum(II)-Acyclovir complexes of acyclovir: synthesis, antiviral and antitumor activity
No full textA platinum(II) complex with the antiviral drug acyclovir was synthesized and its
antiviral and anticancer properties were investigated in comparison to those of acyclovir and
cisplatin. The platinum-acyclovir complex maintained the antiviral activity of the parent
drug acyclovir, though showing a minor efficacy on a molar basis (IDs0 7.85 and 1.02 laM
for platinum-acyclovir and cisplatin, respectively). As anticancer agent, the platinumacyclovir
complex was markedly less potent than cisplatin on a mole-equivalent basis, but it
was as effective as cisplatin when equitoxic dosages were administered in vivo to P388
leukaemia-bearing mice (%T/C 209 and 211 for platinum-acyclovir and cisplatin,
respectively). The platinum-acyclovir complex was also active against a cisplatin-resistant
subline of the P388 leukaemia (%T/C 140), thus suggesting a different mechanism of
action. The DNA interaction properties (sequence specificity and interstrand cross-linking
ability) of platinum-acyclovir were also investigated in comparison to those of cisplatin and
[Pt(dien)C1]+, an antitumour-inactive platinum-triamine compound. The results of this study
point to a potential new drug endowed, at the same time, with antiviral and anticancer
activity and characterized by DNA interaction properties different from those of cisplatin
Isolation of human herpesvirus 7 from an infant with febrile syndrome.
No full textA viral isolate obtained from peripheral blood lymphocytes of an infant with a
nonspecific febrile syndrome was identified as human herpesvirus 7 (HHV-7) on the
basis of PCR analysis of its DNA with one set of primers specific for HHV-7. The
correlation of HHV-7 with the febrile episode affecting the infant is suggested
A three year follow-up of low grade squamous intraepithelial lesions: Persistence of lesions is significantly influenced by the presence of high risk papillomaviruses
No full textA cohort of 921 patients with low-grade squamous intraepithelial lesions (LG-SILs) was studied every six months for a period of 3 years by cytology and colposcopy. Regression of the initial cell injury to a normal cytology was observed in 585/921 cases (63.5%), while cytological abnormalities were still present at the same or higher grade, after three years, in 336/921 cases (36.5%). A sample of 122 Papanicolaou (Pap}stained cervical smears from the cohort of 921 LG-SILs were processed by an in situ hybridization (ISH) assay to search for the presence of DNA of human papillomaviruses (HPVs) considered at high oncogenic risk: 16/18 and 31/35/51. HPV DNA typization was positive for 47/122 lesions (38.5%). Among these 47 lesions associated with high risk HPV DNA, 12 (25.5%) healed and 35 (74.5%) persisted. Of the 75 HPV DNA negative lesions, 46 (61.3%) healed and 29 (38.7%) persisted. The results are discussed in order to define a correct protocol of LG-SIL follow-up
Human herpesvirus-6 dysregulates monocyte-mediated anti cryptococcal defences
No full textIn order to investigate the interplay occurring between pathogens in the course of double infections, an in vitro model was set up in which the monocytic cell line THP-1 was exposed to Cryptococcus neoformans (Cn) and human herpesvirus 6 (HHV-6). Cn and HHV-6, both highly neurotropic, can cause serious diseases of the central nervous system and have monocytes, among other cell types, as target cells, causing alteration of their secretion pattern. Here, it was shown that unlike THP-1 cells exposed to cell-free virus inocula, THP-1 exposed to HHV-6-producing lymphocytes exhibited augmented phagocytosis against Cn. The phenomenon occurred after 24 h of monocyte/lymphocyte co-culture and was independent of direct cell-to-cell contact. Moreover, in the presence of HHV-6, THP-1 cells expressed enhanced secretory responses but reduced capability to counteract fungal infection: the enhanced ingestion by monocytes was followed by facilitated fungal survival and replication. These data provide initial in vitro evidence that HHV-6 may dysregulate monocyte-mediated anticryptococcal defences with an overall pro-cryptococcus result
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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