1,720,977 research outputs found
‘Help yourself, so the (circadian) rhythms help you’:Chronobiological insights to promote physical and mental health
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Chronotherapy of hypertension: let's not throw the baby out with the bathwater!
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Prognostic role of education levels after cardiac surgery and inhospital cardiac rehabilitation
No full textProfilo del trascriptoma piastrinico dell'infarto miocardico acuto
No full textAcute myocardial infarction (AMI) is a sudden event commonly attributed to coronary atherosclerotic plaque rupture with subsequent exposure of thrombogenic substances that promote platelet activation/aggregation as well as coagulation activation and, ultimately, intraluminal thrombus formation thus limiting coronary blood flow. Although plaque rupture or fissuring frequently occurs in atherosclerosis, only a small proportion of ruptured plaques develops thromboses. It has been suggested that individual reactivity to plaque rupture may have a causative role in provoking the clinical event of AMI.
Platelets contribute to the genesis and progression of atherosclerosis and to the precipitation of the atherothrombotic event after plaque rupture. Platelets are anucleate cells formed from the cytoplasm of megakaryocytes and circulate in the blood stream for about 7-10 days. Since platelets are without nucleus, they retain megakaryocytes–derived mRNAs that are unique in representing a nearly fixed transcriptome.
The present study was designed to test whether platelets transcriptome may predate the development of a future myocardial infarction.
The abundance of platelets transcripts levels were measured using Human Transcriptome Array 2.0 (Affymetrix). Bioinformatics analyses were conducted to identify the differentially expressed genes (p.value ≤ 0.05, fold-change ≥ ± 1.5) between patients with ST elevation myocardial infarction (STEMI, n=20), stable coronary artery disease (sCAD, n=20) and healthy donors (HD, n=20). REACTOME and DAVID analyses were performed respectively to identify pathways and biological processes associated with lists of differentially expressed genes (DEGs).
A total of 149 DEGs were observed comparing sCAD patients and HD platelet trascriptome. MNF2 and PRKCD were identified as the most up-regulated genes and CXCL8 as the most down-regulated. A number of 76 DEGs were detected in STEMI subjects compared with HD. S100A12 and CLEC4E, in STEMI patients, resulted the highest up-regulated mRNAs while CXCL8 was the most down-regulated followed by SNORD13, SNORD117 and RMRP. The comparison between STEMI and sCAD subjects allowed the identification of 138 de-regulated genes. S100A12 was again the most up-regulated gene in STEMI. From this preliminary analysis, we observed the presence of distinctive gene-expression patterns for sCAD and STEMI. These results suggested the possibility to find a more specific gene-set for STEMI condition. Thus, we focused on the characterization of a gene-signature able to discriminate patients with myocardial infarction and eventually we identified a STEMI signature consisting of 38 genes from these analyses.
In conclusion, our preliminary results show that variations in gene expression profile of megakaryocytes may occur before of an AMI and that platelet transcriptome could act as a fingerprint indicating the development of a future myocardial infarction.L’infarto miocardico acuto (IMA) è un evento improvviso comunemente attribuito alla rottura di una placca aterosclerotica coronarica cui consegue l’esposizione di sostanze trombogeniche che favoriscono l’attivazione/aggregazione piastrinica e l'attivazione della coagulazione con successiva formazione di un trombo endoluminale che interrompe il flusso sanguigno. Anche se la placca aterosclerotica va spesso incontro a rottura/fissurazione, solo in una piccola percentuale di rotture di placca si sviluppa trombosi. È stato suggerito che la reattività dell’individuo alla rottura di placca può avere un ruolo causale nel determinare un infarto miocardico acuto.
Le piastrine contribuiscono alla genesi e alla progressione dell'aterosclerosi e partecipano al processo di aterotrombosi dopo la rottura della placca aterosclerotica. Le piastrine sono cellule anucleate, si formano dal citoplasma dei megacariociti e circolano nel flusso sanguigno per circa 7-10 giorni. Le piastrine sono prive di nucleo e trasportano mRNA di origine megacariocitaria, pertanto il loro trascrittoma viene considerato essere abbastanza stabile.
Lo scopo del presente studio è di verificare se il trascrittoma piastrinico può essere utile nella predatazione dello sviluppo di un infarto miocardico acuto.
I livelli dei trascritti piastrinici sono stati misurati utilizzando Human Transcriptome Array 2.0 (Affymetrix). Analisi bioinformatiche sono state condotte per identificare i geni espressi in modo differenziale (p.value ≤ 0.05, fold change ≥ ± 1.5) tra i pazienti con infarto miocardico con sopraslivellamento del tratto ST (STEMI, n = 20), malattia coronarica stabile (SCAD, n = 20) e donatori sani (HD, n = 20). Inoltre, sono state effettuate ulteriori analisi utilizzando REACTOME e DAVID, rispettivamente per individuare pathways e processi biologici associati con le liste di geni differenzialmente espressi (DEGs).
Nel confronto del trascritto piastrinico tra pazienti sCAD e HD sono stati rilevati un totale di 149 DEGs. MNF2 e PRKCD sono stati identificati come i geni più up-regolati e CXCL8 come il più down-regolato. 76 DEGs sono stati quindi osservati nei soggetti con STEMI rispetto agli HD. S100A12 e CLEC4E, nei pazienti con STEMI, hanno rappresentato gli mRNA più up-regolati mentre CXCL8 il più down-regolato, seguito da SNORD13, SNORD117 e RMRP. Il confronto tra i soggetti con STEMI e sCAD ha permesso di identificare 138 geni deregolati. S100A12 è risultato essere nuovamente il gene più up-regolato negli STEMI. Da queste analisi preliminari abbiamo osservato la presenza di caratteristici modelli di espressione genica per i pazienti sCAD e STEMI. Questi risultati hanno suggerito la possibilità di trovare un set di geni più specifico per i pazienti con STEMI. Così, ci siamo concentrati sulla caratterizzazione di una gene-signature in grado di discriminare i pazienti con infarto miocardico e, alla fine, da questi analisi abbiamo individuato una “signature” dell’infarto miocardico con sopraslivellamento del tratto ST costituita da 38 geni.
In conclusione, i nostri risultati preliminari indicano che variazioni nel profilo di espressione genica potrebbero verificarsi nei megacariociti giorni prima di un infarto miocardico acuto e che il trascriptoma piastrinico potrebbe agire come un potente “fingerprint” indicativo dello sviluppo di un futuro evento coronarico acuto
Cardiac calcium score on 2D echo: correlations with cardiac and coronary calcium at multi-detector computed tomography
No full textBackground: To test the hypothesis that a semi-quantitative echocardiographic calcium score (eCS) significantly correlates with cardiac calcium measured by coronary computed tomography angiography (CCTA) and, secondarily, severe coronary artery calcifications and stenosis. Methods: This is a retrospective, observational study, conducted in a tertiary centre. eCS was compared with CCTA scores of non-coronary cardiac calcium (nCACS), coronary cardiac calcium (CACS) and number of diseased coronary vessels, in 141 subjects without known coronary artery disease (CAD), who underwent both echocardiography and CCTA for clinical reasons. Results: Age, prevalence of hypertension and all measures of calcium (eCS, nCACS and CACS) differed significantly between the no-CAD and CAD subgroups. eCS was positively correlated with nCACS (Spearman rho = 0.64, p 400), a known predictor of cardiovascular morbidity and mortality. The eCS also predicts obstructive CAD, incrementally to age and clinical variables, although for this purpose CACS remains the most accurate score
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
Multiparametric carotid and cardiac ultrasound compared with clinical risk scores for the prediction of angiographic coronary artery disease: A multicenter prospective study
No full textOBJECTIVE:
Cardiovascular risk prediction is deemed fundamental and the assessment of organ damage is emerging as a potentially 'downstream' picture of individual risk. Our aim was to assess the feasibility and value of prediction of coronaropathy [coronary artery disease (CAD)] of integrated cardiovascular ultrasound examination.
METHODS:
This multicenter study involved eight cardiology centers that enrolled 457 consecutive patients. Blood pressures, carotid intima-media thickness (cIMT), carotid pulse wave velocity (cPWV), semiquantitative score of cardiac calcifications, global myocardial longitudinal strain (GLS), and rest Doppler flow velocity on the left anterior descending (LAD) coronary artery were measured. After coronary angiography, patients were divided in CAD, n = 273, at least one coronary stenosis higher than 50%, and no CAD, n = 184.
RESULTS:
CAD were older (65.9 ± 10.7 versus 63.1 ± 11.2 years, mean ± standard deviation, P = 0.01), and had higher blood pressure (137.0 ± 18.8/77.5 ± 11.1 versus 130.2 ± 17.4/75.1 ± 9.7 mmHg, P < 0.02), cIMT (791.4 ± 165.5 versus 712.0 ± 141.5 mcm, P < 0.0001), cPWV (median: 9 versus 8.1 m/s, P < 0.01), score of calcium (median, 2 versus 1, P < 0.0001), LAD velocity (median, 38 versus 36, P < 0.07), and lower GLS (-17.6 ± 4.3 versus -19.3 ± 5.1, P < 0.05) than no CAD. Score of calcium was feasible in the totality of patients, cIMT in 97%, cPWV in 86%, GLS in 88%, and LAD in 84%. A combination of at least three variables was measurable in 80% of the patients. All ultrasound parameters significantly predicted CAD. However, in a stepwise logistic regression, the only combined predictors of obstructive CAD were score of calcium, cIMT, and LAD velocity.
CONCLUSION:
In Echo-Lab, Rome, Italy, the integrated cardiovascular ultrasound study is feasible in a high percentage of patients. The combination of three parameters, that is, score of calcium, cIMT, and LAD velocity, has incremental predictive value for obstructive CAD
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