1,720,968 research outputs found
COVID-19 Deaths: Are We Sure It Is Pneumonia? Please, Autopsy, Autopsy, Autopsy!
Full text linkThe current outbreak of COVID-19 severe respiratory disease, which started in Wuhan, China, is an ongoing challenge, and a major threat to public health that requires surveillance, prompt diagnosis, and research efforts to understand this emergent pathogen and to develop an effective response. Due to the scientific community’s efforts, there is an increasing body of published studies describing the virus’ biology, its transmission and diagnosis, its clinical features, its radiological findings, and the development of candidate therapeutics and vaccines. Despite the decline in postmortem examination rate, autopsy remains the gold standard to determine why and how death happens. Defining the pathophysiology of death is not only limited to forensic considerations; it may also provide useful clinical and epidemiologic insights. Selective approaches to postmortem diagnosis, such as limited postmortem sampling over full autopsy, can also be useful in the control of disease outbreaks and provide valuable knowledge for managing appropriate control measures. In this scenario, we strongly recommend performing full autopsies on patients who died with suspected or confirmed COVID-19 infection, particularly in the presence of several comorbidities. Only by working with a complete set of histological samples obtained through autopsy can one ascertain the exact cause(s) of death, optimize clinical management, and assist clinicians in pointing out a timely and effective treatment to reduce mortality. Death can teach us not only about the disease, it might also help with its prevention and, above all, treatment
Antenatal Glucocorticoids Supplementation and Central Nervous System Development
No full textMaternal antenatal therapy with glucocorticoids (GC) is routinely used to prevent lung immaturity. The potential harmful effects on other organs, including in particular the central nervous system (CNS), are still controversial. In the present review we aimed to investigate: i) the beneficial and detrimental effects of antenatal GC treatment in both human and animal models; ii) the potential usefulness of biochemical markers such as calcium binding proteins (S100B, synaptophysin) and cytoskeletal protein of neurons and dendrites (MAP2) in the perinatal period, and iii) whether the assessment of brain markers in different biological fluids could constitute a promising tool for the monitoring of CNS function and/or developmental in fetuses and newborns whose mothers assumed GC antenatally
Carbon monoxide signaling in promoting angiogenesis in human microvessel endothelial cells
No full textHeme oxygenase isoforms (HO-1/HO-2) catalyze the conversion of heme to carbon monoxide (CO) and bilirubin. In this study, HO-1-deficient endothelial cells were transduced with HO-1 in the antisense orientation to determine whether supplementation with CO or bilirubin would regulate cell proliferation and angiogenesis. Western blotting, enzyme activity, CO and prostaglandin E(2) (PGE(2)) production, and cell-cycle analysis were used to assess transgenic expression and functionality of the recombinant protein. A Matrigel matrix was used for assessment of in vitro capillary formation. Transduction with HO-1 antisense resulted in decreased capillary formation, cell proliferation, and cell-cycle progression, and increased PGE(2) production compared with control. HO-1 deficiency was also associated with increased expression of p21 and p27, but had no significant effect on p16 and p53. We also compared two different CO donors for their ability to rescue angiogenesis. Compared with control, HO-1-deficient endothelial cells showed increased angiogenesis following tricarbonyldichlororuthenium( II) dimer ([Ru(CO)(3)Cl(2)](2)) (CORM-1) starting at 50 microM, whereas tricarbonylchloro(glycinato) ruthenium(II) (CORM-3), starting at 25 microM, was a potent enhancer of angiogenesis. The addition of bilirubin did not restore angiogenesis. These data suggest that HO-mediated angiogenesis and cell proliferation were dependent on HO-1- and not HO-2-derived CO
Circulatory responses to asphyxia differ if the asphyxia occurs in utero or ex utero in near-term lambs
No full textBACKGROUND: A cornerstone of neonatal resuscitation teaching suggests that a rapid vagal-mediated bradycardia is one of the first signs of perinatal compromise. As this understanding is based primarily on fetal studies, we investigated whether the heart rate and blood pressure response to total asphyxia is influenced by whether the animal is in utero or ex utero. METHODS: Fetal sheep were instrumented at ∼ 139 days of gestation and then asphyxiated by umbilical cord occlusion until mean arterial blood pressure decreased to ∼ 20 mmHg. Lambs were either completely submerged in amniotic fluid (in utero; n = 8) throughout the asphyxia or were delivered and then remained ex utero (ex utero; n = 8) throughout the asphyxia. Heart rate and arterial blood pressure were continuously recorded. RESULTS: Heart rate was higher in ex utero lambs than in utero lambs. Heart rates in in utero lambs rapidly decreased, while heart rates in ex utero lambs initially increased following cord occlusion (for ∼ 1.5 min) before they started to decrease. Mean arterial pressure initially increased then decreased in both groups. CONCLUSIONS: Heart rate response to asphyxia was markedly different depending upon whether the lamb was in utero or ex utero. This indicates that the cardiovascular responses to perinatal asphyxia are significantly influenced by the newborn's local environment. As such, based solely on heart rate, the stage and severity of a perinatal asphyxic event may not be as accurate as previously assumed
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
Neuromarkers and unconventional biological fluids
No full textThere is a growing evidence on the use of biomarkers in daily practice both as of markers of brain/multiorgan damage and/or trophic factors. However, among different tools, Activin A, S100B protein, and Hemeoxygenase-1 (HO-1 or Heat Shock Protein 32, HSP32) assessment offer the possibility to investigate brain/multiorgan function and development. This could be especially useful in perinatal medicine that requires even more noninvasive techniques to fulfill the minimal handling diagnostic and therapeutic strategy. In this regard, among different biological fluids, human milk for its unique composition can constitute a wide source of knowledge useful both in clinical daily practice and in research.Therefore, this mini-review reports recent data on the presence and the usefulness of Activin A, S100B protein, and HO-1/HSP32 assessment in human milk as brain/multiorgan development markers. Results open up a new cue on the use of these markers in perinatal medicine as a key protein for investigations focusing on fetal/neonatal development
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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