1,721,005 research outputs found
Valutazione della funzione piastrinica in relazione alle variazioni ormonali del ciclo mestruale: prospettive di genere
Full text linkIntroduzione - Le malattie aterotrombotiche sono la causa di circa il 25% di tutte le morti nei soggetti di sesso femminile e rappresentano inoltre patologie ad elevata morbilità e costo socio-sanitario. Esistono differenze di incidenza, modalità di presentazione e risposta alla terapia antipiastrinica relate al genere che rimangono, tuttora, ampiamente inspiegate. Tra i meccanismi chiamati in causa vi sono le differenze nella reattività piastrinica.
Obiettivo dello studio: Valutare se esista una relazione tra indici di attivazione piastrinica e variazioni degli ormoni sessuali durante un fisiologico ciclo mestruale regolare.
Materiali e Metodi - Sono state incluse nello studio 22 donne in età fertile (28 ± 2 giorni) sane, di età compresa tra i 18 e i 40 anni. In ogni soggetto sono stati valutati il profilo ormonale a tempo 1, 5, 14, 21 giorni del ciclo mestruale e gli indici di attivazione piastrinica [misurata mediante marcatori di attivazione piastrinica in vivo, quali la produzione di trombossano B2 (TxB2) ed i livelli circolanti di CD40L e P-selectina].
Risultati - I valori di TxB2 sono risultati significativamente aumentati, rispetto al basale, a 7 e 21 giorni (p=0.003 e p<0.001, rispettivamente), mentre al 14° giorno, in corrispondenza del picco estrogenico, sono risultati significativamente ridotti (p<0.02 vs. T2, p<0.001 vs. T4). I livelli di P-selectina solubile sembrano avere un comportamento similare. Tuttavia, non esiste una correlazione diretta tra profilo ormonale e attivazione piastrinica in nessun momento del ciclo. Peraltro, i valori di TxB2 rispetto ai valori mediani di estrogeno, valutati in ogni momento del ciclo, sono significativamente più bassi quando i livelli di estrogeni superano la mediana dell’intera distribuzione (p<0.02).
Conclusioni - I bassi livelli di TxB2 sierico osservati nel momento del picco estrogenico così come la relazione indiretta tra i due parametri supportano il cosiddetto «ruolo protettivo» dell’estrogeno nelle donne in età fertile nei confronti delle malattie aterotrombotiche. Tuttavia, l’ampia modulazione dei parametri di attivazione piastrinica durante le fasi del ciclo potrebbe giustificare l’interazione di recettori ormonali sull’attivazione piastrinica spiegando, in parte, la diversa risposta all’aspirina nelle donne sia in prevenzione primaria che secondaria.
La possibile variabilità della lunghezza della fase post-ovulatoria intra soggetti potrebbe spiegare la mancata correlazione lineare tra i parametri ormonali e quelli di attivazione piastrinica analizzati. Ciò limita lo studio e rende necessario l’ampliamento della casistica
The 35-year odyssey of beta blockers in cirrhosis: any gender difference in sight?
No full textCirrhosis is the end-stage of chronic liver disease and leads to the development of portal hypertension
and its complications such as esophagogastric varices. Non-selective beta blockers (NSBB) are the keystone
for the treatment of portal hypertension since the 1980s and, over the decades, several studies
have confirmed their beneficial effect on the prevention of variceal (re)bleeding. Pharmacological studies
showed effects of gender, sex hormones, oral contraceptives, and pregnancy on cytochrome P450
(CYPs) enzymes that metabolise NSBB, suggesting that gender differences might exist in the effect of
NSBB. In this review, we focused on the 35-year knowledge about the use of beta blockers in cirrhosis
and potential gender differences. We specifically examined the role of NSBB in pre-primary, primary and
secondary prophylaxis of variceal bleeding, compared two commonly used NSBB (i.e., Propranolol and
Carvedilol), and present the current controversies about the window of treatment in advanced cirrhosis
with a specific focus on gender differences in NSBB effects. NSBB are not currently recommended in preprimary
prophylaxis of varices mainly because of lack of proven efficacy. On the other hand, NSBB are
strongly recommended in patient with cirrhosis as primary (as alternative to endoscopic band ligation,
EBL) and secondary prophylaxis (in addition to EBL) of variceal bleeding. To date, no studies have focused
specifically on the effect of gender on NSBB treatment. Data extrapolated from clinical studies show that
gender was neither a risk factor for the development of varices nor associated with a different response
to treatment in primary or secondary prophylaxis. According to the available guidelines, no different,
gender-based treatment for portal hypertension is recommended
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
Asymptomatic peripheral artery disease and antiplatelet management
No full textPeripheral arterial disease (PAD) is a hallmark of generalized atherosclerosis. Depending on the specific diagnostic criteria that are being used, the prevalence of PAD may be as high as 30 % in the population of people 70 or more years old. Unfortunately, although PAD is prevalent and has many important consequences for patients, it is often under-detected and under-treated by primary care physicians. The aim of this review is to provide an overview of the available literature on epidemiology and antiplatelets management of PAD patients. In particular, we focus on the "hidden" side of PAD burden, the asymptomatic patients, who are at high risk of negative cardiovascular outcomes. Identification of such PAD patients is therefore an important clinical goal to reduce mortality and morbidity and reduce the social cost of atherosclerotic disease. Early screening of PAD and an evidence-based antithrombotic approach are also discussed as potential strategies to counteract the negative impact of such condition in general population, as well as, in patients with other cardiovascular disease
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
Inflammation and Thrombophilia in Pregnancy Complications: Implications for Risk Assessment and Clinical Management
No full textIn Italy, each year 500000 couples refer to specialized centers due to reproductive problems. Among them, recurrent pregnancy loss (RPL) represents a problem of great importance, given that it affects up to 5% of women of childbearing age. Infertility, on the other hand, is a condition that currently covers 10-20% of couples of reproductive age, being idiopathic in 20% of cases. Accumulating evidence support the concept that changes of blood coagulation, generically defined as the presence of a thrombophilic state (congenital or acquired), are the basis of 40-70% of cases of multiple abortions or infertility. Several evidences support the hypothesis that endothelial dysfunction, a hallmark of a condition of low-grade inflammation, is one of the earliest manifestations of thrombotic phenomena. To date, it's believed that, while the antiinflammatory Th2 cytokines (i.e. interleukin-10) can exert a protective role in pregnancy, the pro-inflammatory Th1 ones (i.e. interferon-γ, tumor necrosis factor-α,) have deleterious effects on pregnancy outcome, including fertilization and implantation failure. Moreover, development of many pregnancy complications, first and foremost venous thromboembolism (VTE), recognizes similar mechanism(s). As VTE is the main preventable cause of mortality during pregnancy, thromboprophylaxis is mandatory according to individual VTE risk, influenced by the presence of thrombophilic conditions. In this review, we will analyze the relationship between thrombophilia and pregnancy complications, with particular focus on the role of inflammation. Subsequently, we will consider some issues related to the thromboembolic risk in pregnancy. Finally, the role of thromboprophylaxis in pregnancy will be discussed
Dasatinib overcomes imatinib and nilotinib failure in Philadelphia chromosome positive chronic myeloid leukemia with different mechanisms of resistance
No full text[No abstract available
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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