1,720,994 research outputs found
Evidenze istopatologiche e di microscopia elettronica a scansione di danno epatico in corso di COVD-19
No full textINTRODUZIONE: La patologia COVID-19 ha ormai dimostrato un coinvolgimento di numerosi visceri oltre al ben noto quadro di polmonite interstiziale. In particolare, nei pazienti affetti da COVID-19 è stata riscontrata la presenza di segni clinici di danno epatico. Questa condizione sembrerebbe essere caratterizzata da un outcome severo e potrebbe essere correlata alla capacità del SARS-CoV-2 di attivare le cellule T citotossiche. Si presenta un lavoro recentemente pubblicato1 che si propone di verificare il coinvolgimento epatico nei pazienti con COVID-19 attraverso le caratteristiche istologiche e di microscopia elettronica a scansione al fine di mettere in evidenza le alterazioni patologiche epatiche determinate da pathways molecolari multipli attivati a seguito di questa infezione.
MATERIALI E METODI: sono stati studiati, mediante analisi istologica e di microscopia elettronica a scansione, i tessuti epatici prelevati in corso di autopsie giudiziarie (n=3) e di biopsia in vivo (n=1) da individui affetti da COVID-19.
RISULTATI: le alterazioni epatiche hanno mostrato una significativa eterogeneità. Il primo caso ha dimostrato la presenza di epatociti a vetro smerigliato e aggregati di fibrina sparsi nel lume sinusoidale. Il secondo evidenziava la presenza di trombi intra-sinusoidali. Il terzo era caratterizzato da dilatazione sinusoidale, atrofia degli epatociti, dilatazione degli spazi di Disse e aggregati intra-sinusoidali di fibrina e globuli rossi. Il quarto caso mostrava aggregati di fibrina diffusi negli spazi di Disse dilatati e microtrombi nel lume sinusoidale. Nei 3 casi fatali è stato possibile evidenziare una serie di lesioni suggestive per un fenotipo protrombotico indotto dall’infezione Sars-CoV-2.
CONCLUSIONI: Nel danno epatico COVID-19 correlato, è stato osservato un ampio spettro di alterazioni patologiche. Le caratteristiche maggiormente peculiari sono rappresentate dai cambiamenti intra-sinusoidali, inclusa la dilatazione dei sinusoidi e dalla sinusoidite trombotica con deposizione diffusa di fibrina intra-sinusoidale, in un quadro di lieve infiammazione. Questi risultati suggeriscono che la sinusoidite trombotica seguita dalla coagulazione intravascolare (intra-sinusoidale) locale potrebbe rappresentare il segno cardine del danno epatico correlato a SARS-CoV-2.
1Fanni D, Cerrone G, Saba L, Demontis R, et al; Thrombotic sinusoiditis and local diffuse intrasinusoidal coagulation in the liver of subjects affected by COVID-19: the evidence from histology and scanning electron microscopy. Eur Rev Med Pharmacol Sci. 2021 Oct;25(19):5904-5912. doi: 10.26355/eurrev_202110_2686
Su un caso di morte asfittica in corso di intubazione orotracheale pre-anestesia su paziente con malformazione delle strutture del collo.
No full textSingolari esemplari di armi da fuoco rudimentali utilizzati nella pratica venatoria illecita, responsabili di ferimenti accidentali in campagna.
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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
Lethal aorto-oesophageal fistula 16 years after aortic prosthetic reconstruction: Delayed rupture as cause of death
No full textThe development of aorto-oesophageal fistula (AOF) is a rare complication following thoracic aortic repair. Mortality is high, in most cases due to fatal haematemesis. The clinical onset is variable, occurring approximately one year after surgery. We report a case of a lethal AOF in a 58-year-old man. He underwent open vascular surgery 16 years prior to his death due to a rupture of the descending thoracic aorta. In the early 2000s, the open vascular approach was replaced by thoracic endovascular aortic repair. As a result of this approach, the number of surgical complications has reduced, with the exception of AOF
Volabolomic Fingerprinting for Post-Mortem Interval Estimation: A Novel Physiological Approach
Full text linkDeath is a multifaceted process wherein each individual cell and tissue has a metabolic homeostasis and a time of functional cessation defined by the dying process as well as by intrinsic and extrinsic factors. Decomposition is physiologically associated with the release of different types of volatile organic compounds (VOCs), and these form volaboloma mortis. The main purpose of this study was to record the volabolomic fingerprint produced by volatile molecules during the physiological decomposition process of human tissue and muscle cells. The volatile chemical signature has important implications for an open issue in forensics and pathology, namely the estimation of the postmortem interval (PMI), which decreases in accuracy with the passage of time. Volatile metabolites emitted from human tissues and muscle cells at 0, 24, 48, and 72 h were recorded in real time with an electronic nose sensor device. The key findings were the continuous sampling of VOCs emitted from tissues and cells. These showed a common behavior as time progressed; particularly, after 48 h the distributions became dispersed, and after 72 h they became more variable. Volabolomic fingerprinting associated with time progression relevant to the study of PMIs was reconstructed. Additionally, there may be broader applications, such as in dog training procedures for detecting human remains, and perhaps even for studying scavenger and insect attractants
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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