1,720,970 research outputs found
Confocal laser scanning microscopy. Using new technology to answer old questions in forensic investigations
Levamisole adulterated cocaine and pulmonary vasculitis: presentation of two lethal cases and brief literature review
The first case reports of levamisole-related disease in cocaine users were published in 2010, although levamisole adulteration of cocaine was first recognized several years earlier. Currently, more than 70% of street cocaine seizures, in the US and the EU, contain levamisole, which could potentially be converted to aminorex, though the reasons for this practice still remain obscure. Here we report two fatal cases of isolated pulmonary vasculitis in abusers of levamisole-adulterated cocaine, where a complete autopsy, full toxicological analysis by gas chromatography-mass spectrometry (GC-MS) using a previously published method of Karch et al. and histological examination were performed. A control group composed of 11 cases of cocaine related deaths, where the presence of levamisole was excluded in blood, urine and hair, was used. Recent literature on the human pharmacokinetics of levamisole and aminorex is also reviewed. The toxicological analysis revealed positive qualitative and quantitative results for cocaine, benzoylecgonine and levamisole in both cases. In case 1 levamisole was found at the concentration of 13.5 and 61.3mg/L in blood and urine respectively, whereas in case 2 at 17.9 and 70.2mg/L. The histological examination highlighted in case 1 in heart samples microscopic evidence of the typical remodeling changes associated with chronic stimulant abuse, whereas lungs showed numerous lymphocytes surrounding and infiltrating the wall of small pulmonary vessels and a perivascular fibrosis with transforming fibroblasts. In case 2, the myocardial samples showed wide fields of myocardial necrosis characterized by hypercontraction of the myocytes with thickened Z-lines and short sarcomeres, whereas lung samples showed a significant intimal thickening of arteriole walls and lymphocytic infiltration of the wall and edema. Moreover, there were also numerous perivascular lymphocytic infiltrates. Although the pathological cardiac findings have allowed us to establish the cause of death in both cases, the presence of pulmonary vasculitis in the lungs represent a further complication. If the disease had progressed to hemorrhage, it certainly would have been a contributory cause of death. The two cases here reported allow us to advance a hypothesis about the possible correlation between the consumption of levamisole adulterated cocaine and pulmonary vasculitis and the comparison of these findings with the control group support this hypothesis. However, this hypothesis is still weak, taking into consideration the fact that pulmonary vasculitis was detected in 2 cases only, making it impossible to exclude a different etiology of this finding. Only through careful histological lung examinations of further cases of fatalities, related to levamisole adulterated cocaine, can this hypothesis be confirmed or refuted
Role of induced pluripotent stem cells in diagnostic cardiology
Ethical concerns about stem cell-based research have delayed important advances in many areas of medicine, including cardiology. The introduction of induced pluripotent stem cells (iPSCs) has supplanted the need to use human stem cells for most purposes, thus eliminating all ethical controversies. Since then, many new avenues have been opened in cardiology research, not only in approaches to tissue replacement but also in the design and testing of antiarrhythmic drugs. This methodology has advanced to the point where induced human cardiomyocyte cell lines can now also be obtained from commercial sources or tissue banks. Initial studies with readily available iPSCs have generally confirmed that their behavioral characteristics accurately predict the behavior of beating cardiomyocytes in vivo. As a result, iPSCs can provide new ways to study arrhythmias and heart disease in general, accelerating the development of new, more effective antiarrhythmic drugs, clinical diagnoses, and personalized medical care. The focus on producing cardiomyocytes that can be used to replace damaged heart tissue has somewhat diverted interest in a host of other applications. This manuscript is intended to provide non-specialists with a brief introduction and overview of the research carried out in the field of heart rhythm disorders
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
“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
We 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
Cardiac pathology in death from electrocution
To better characterize the morphologic changes in electrocution, morphologic changes in the hearts of 21 subjects, who died instantaneously of electrocution, were compared to the hearts of decedents with different types of death. Sixteen myocardial samples per heart were processed for histological examination, and sections were prepared with a variety of specific stains. The frequency, location and extent of myocellular segmentation (stretching and/or rupture) of intercalated discs and associated changes of myocardial bundles and single myocells [myofibre break-up (MFB)] were recorded, quantitatively analysed and statistically evaluated. The frequency of MFB was maximal in cases of electrocution (90%). The findings show that MFB is an ante-mortem change and may be a distinct finding in electrocutio
Sudden cardiac death during anabolic steroid abuse: morphologic and toxicologic findings in two fatal cases of bodybuilders
We report two cases of sudden cardiac death (SCD) involving previously healthy bodybuilders who were chronic androgenic-anabolic steroids users. In both instances, autopsies, histology of the organs, and toxicologic screening were performed. Our findings support an emerging consensus that the effects of vigorous weight training, combined with anabolic steroid use and increased androgen sensitivity, may predispose these young men to myocardial injury and even SCD
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