1,720,984 research outputs found
An Uncommon Presentation of Tuberculosis with Cervical Pott's Disease Initially Suspected as Metastatic Lung Cancer
No full textCervical Pott’s disease is a rare clinical condition whose diagnosis is usually delayed. We report a case of lung tuberculosis (TB) and cervical Pott’s disease mimicking a metastatic lung cancer. The patient presented with persistent cervical pain. Radiologic examinations showed the presence of a lytic lesion of C3 vertebral body, associated with spinal cord compression. A CT scan of the thorax showed a lung nodule highly suspicious for malignancy in the apical region of right lung upper lobe. Neurosurgical decompression was performed. Unexpectedly, histological analysis showed the presence of an inflammatory infiltrate suggestive for TB infection. The patient was immediately treated with antituberculous drugs. Atypical forms of spinal TB, such as cervical TB, can be misdiagnosed as primary or metastatic cancers and lead to delay of treatment initiation that could be fatal. Awareness of this uncommon TB presentation is important to prevent morbidity and mortality associated with spinal cord injury and disease dissemination
An Unusual Case of Fibromuscular Dysplasia with Bilateral Renal Macroaneurysms: Three-year Outcome After Endovascular Treatment
Full text linkLipoprotein remnants and dense LDL are associated with features of unstable carotid plaque: A flag for non-HDL-C
Full text linkOBJECTIVE: We investigated the association between cholesterol across the LDL density range and in the VLDL and IDL particles with the prevalence of inflammatory cells in plaques of patients with severe carotid artery stenosis.
METHODS: Forty-five patients undergoing carotid endarterectomy were studied. Plaque specimens were analyzed for cellular composition by immunocytochemistry using monoclonal antibodies. Lipoprotein subclasses were separated by gradient ultracentrifugation.
RESULTS: We found no correlations between LDL-C, HDL-C and plasma triglyceride levels with plaque cellular composition. On the other hand, macrophage content was significantly related to cholesterol in the dense LDL subclasses (r = 0.30, p < 0.01) and in the triglyceride-rich lipoprotein remnants, namely dense VLDL and IDL particles (r = 0.46, p < 0.01). HDL subclasses were not correlated with plaque cellular composition. In a mirror manner, smooth muscle cells were inversely associated with cholesterol levels of the dense LDL subclasses (r = -0.32, p < 0.01 fraction 10; r = -0.26, p < 0.05 fraction 11) while only a non-significant trend was observed with the cholesterol in the VLDL-IDL fractions. These results provide the pathophysiological background to account for the relevance of non-HDL-C as the only lipid parameter, aside LDL density, significantly associated (β = 0.351, p = 0.021) with carotid plaque macrophage content.
CONCLUSIONS: We provide evidence that lipoprotein subclasses, specifically cholesterol in the dense LDL fractions and in the triglyceride-rich lipoprotein remnants, significantly affect carotid plaque cellular composition, in particular macrophages content
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
Extracellular pyrophosphate is reduced in aortic interstitial valve cells acquiring a calcifying profile: Implications for aortic valve calcification
No full textObjectives: Pyrophosphate (PPi) is a potent inhibitor of ectopic mineralization but its role during aortic valve calcification is not known. Methods: Anti-calcific effect of PPi was investigated by using an in vitro model of serum-driven calcification of collagen sponges and decellularized porcine aortic valve leaflets. Bovine interstitial valve cells (VIC), seeded either within the collagen matrices or in transwell chambers, were used to test cellular ability to inhibit serum-induced calcification. PPi metabolism was investigated in clonal VIC harboring different calcifying potential. Results: In a cell-free system, high serum levels induced a dose-dependent calcification of type I collagen matrices which was prevented by PPi and ATP supplementation. Blockade of serum-driven calcification by PPi and ATP was also observed when using decellularized porcine aortic valve leaflets. A similar anti-calcific effect was also seen for bovine VIC, either statically seeded into the collagen matrices or co-cultured by using a transwell system. However, when we performed co-culture experiments by using clonal VIC harboring different calcifying potential, we observed that the subset of cells acquiring a pro-calcific profile lost the ability to protect the collagen from serum-driven calcification. Pro-calcific differentiation of the clonal VIC was accompanied by increase in ALP along with significant reduction in NPP activity and ATP/PPi extracellular accumulation. These changes were not observed in the clonal subtype with lower propensity towards calcification. Conclusions: We showed that PPi and ATP are potent inhibitors of serum-driven calcification of collagen matrix and that their extracellular accumulation is reduced in calcifying VIC
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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