Information load dynamically modulates functional brain connectivity during narrative listening.

Narratives are paradigmatic examples of natural language, where nouns represent a proxy of information. Functional magnetic resonance imaging (fMRI) studies revealed the recruitment of temporal cortices during noun processing and the existence of a noun-specific network at rest. Yet, it is unclear whether, in narratives, changes in noun density influence the brain functional connectivity, so that the coupling between regions correlates with information load. We acquired fMRI activity in healthy individuals listening to a narrative with noun density changing over time and measured whole-network and node-specific degree and betweenness centrality. Network measures were correlated with information magnitude with a time-varying approach. Noun density correlated positively with the across-regions average number of connections and negatively with the average betweenness centrality, suggesting the pruning of peripheral connections as information decreased. Locally, the degree of the bilateral anterior superior temporal sulcus (aSTS) was positively associated with nouns. Importantly, aSTS connectivity cannot be explained by changes in other parts of speech (e.g., verbs) or syllable density. Our results indicate that the brain recalibrates its global connectivity as a function of the information conveyed by nouns in natural language. Also, using naturalistic stimulation and network metrics, we corroborate the role of aSTS in noun processing.

Radiofrequency-based wall tracking for noninvasive assessment of local carotid pulse pressure: comparison with applanation tonometry and association with organ damage.

OBJECTIVES: Central pulse pressure (PP) has been suggested a better predictor of cardiovascular risk than brachial PP, and its routine noninvasive assessment can be useful for risk stratification. The present study evaluated the capability of a radiofrequency-based carotid wall tracking to estimate central PP from distension curves, comparing the values of carotid PP as obtained by wall tracking with those provided by applanation tonometry. Furthermore, the associations of carotid PP with intermediate markers of cardiovascular risk, like carotid intima-media thickness (IMT) and left ventricular mass (LVM), were assessed. METHODS: Carotid PP was measured by wall tracking and applanation tonometry during the same session in 346 individuals (healthy controls, patients with hypertension and diabetes). IMT was measured in all individuals and LVM was measured in 253. RESULTS: Carotid PP values as measured by wall tracking and applanation tonometry were highly correlated [r = 0.87; slope 0.90 (0.85-0.95); P < 0.0001; mean difference = 3.1 ±â€Š6.8 mmHg], and were independently determined by the same variables (age, heart rate, triglycerides, blood pressure-lowering therapy). Carotid IMT and LVM correlated more strongly with carotid PP (r = 0.44 and 0.50; P < 0.0001 for both) than with brachial PP (r = 0.34 and 0.42; P < 0.0001 for both). Patients with carotid PP at least 50 mmHg had higher IMT, LVM, and prevalence of LV hypertrophy than those with PP less than 50 mmHg (P = 0.0001 to <0.0001). CONCLUSIONS: Local carotid PP as estimated by wall tracking is comparable to that obtained by applanation tonometry, and it shows a better association with target organ damage than brachial blood pressure. Assessment of carotid PP during routine ultrasound examination of extracranial carotid tree may provide additional information for individual risk stratification.

N-terminal fragment of B-type natriuretic peptide predicts coexisting subclinical heart and vessel disease.

BACKGROUND: Identification of preclinical cardiovascular disease represents a challenge. We evaluate N-terminal proB-type natriuretic peptides (NT-proBNP) as markers of both cardiac and vascular subclinical disease in a community-based study including asymptomatic middle- aged study participants. METHODS AND RESULTS: In total, 807 study participants without previous cardiovascular disease were recruited. They underwent thorough laboratory assessment (including NT-proBNP), ultrasound examination of heart and evaluation of coronary calcium score and carotid intima-media thickness, by computed tomography and ultrasound, respectively.Cardiac and vascular disease were defined as one among left ventricular (LV) ejection fraction less than 50% (3.1%), E/E' ratio more than 15 (9%), LV mass index more than 115 in men or more than 95 g/m in women (20%), LV end diastolic diameter more than 55 mm (2.5%), coronary calcium score more than 100 AU (13%), or carotid intima-media thickness more than 1.2 mm (21%), respectively. NT-proBNP [OR, 1.275; 95% (confidence interval) CI, 1.007-1.613, P < 0.001], 10-year Framingham risk score (FRS; OR 1.132; 95% CI, 1.058-1.212, P < 0.001) and lower creatinine clearance (OR, 0.983; 95% CI, 0.971-0.994, P < 0.001) predicted cardiac (220, 27%), whereas 10-year Framingham risk score (OR, 1.340; 95% CI, 1.245-1.674, P < 0.001) and NT-proBNP (OR, 1.501; 95% CI, 1.181-1.907, P < 0.001) predicted vascular involvement (215, 26%), at multivariate analysis. In total, 84 study participants (10.1%) had coexisting cardiac and vascular disease. NT-proBNP increased linearly from health study participants to study participants with only cardiac or vascular involvement, up to coexisting cardiovascular disease. CONCLUSION: Coexisting cardiac and vascular involvement in asymptomatic study participants is common. Along with traditional risk factors, NT-proBNP appears a valuable biomarker for global subclinical heart and vessels disease.

N-terminal prob-type natriuretic peptide is a marker of vascular remodelling and subclinical atherosclerosis in asymptomatic hypertensives.

BACKGROUND: Arterial hypertension is a main determinant of arterial remodelling and atherosclerosis. Coronary artery calcium score and carotid intima-media thickness are recognized indices of vascular remodelling. Established biohumoral markers for the diagnosis of atherosclerosis are still lacking in asymptomatic subjects with hypertension. OBJECTIVES: We aimed to test the association of plasma N-terminal pro B-type natriuretic peptide concentrations with either coronary artery calcium score or carotid intima-media thickness in asymptomatic hypertensive subjects. METHODS: We conducted a case-control study on 436 hypertensi.ve and 436 age/sex-matched normotensive subjects from the population of the Montignoso HEart and Lung Project, a community-based study of asymptomatic general population ≥45 years. Subjects underwent N-terminal pro B-type natriuretic peptide measurement, echocardiography and evaluation of coronary artery calcium score and carotid intima-media thickness. RESULTS: Hypertensive subjects had higher median coronary artery calcium score (60 (interquartile range, 30-112) vs. 15 (interquartile range 3-70) Agatson units, p = 0.007), carotid intima-media thickness (8.6 (interquartile range 7.5-9.1) vs. 7.9 (7.1-8.4) µm, p < 0.001) and indexed left ventricular mass (101 (interquartile range 82-126) vs. 87 (63-91) mg/m2, p = 0.03) than controls, with no differences in left ventricular ejection fraction, diameters, E/E', left atrial area. N-terminal pro B-type natriuretic peptide concentrations were higher in hypertensive subjects with either coronary artery calcium score (p = 0.008) or carotid intima-media thickness >75th (p < 0.006) percentile and highest in combined coronary artery calcium score/carotid intima-media thickness >75th percentile (p = 0.021). In multivariable analysis, N-terminal pro B-type natriuretic peptide independently predicted either coronary artery calcium score or carotid intima-media thickness >75th percentile, but only in hypertensive subjects (odds ratio = 1.87, 95% confidence interval 1.30-2.74, p = 0.001 and odds ratio = 1.99, 95% confidence interval 1.43-2.76, p = 0.001). CONCLUSIONS: In asymptomatic subjects with hypertension, N-terminal pro B-type natriuretic peptide is a marker of hypertension-mediated preclinical vascular disease.

The calculation of the cardiac troponin T 99th percentile of the reference population is affected by age, gender, and population selection: a multicenter study in Italy.

BACKGROUND: The aim of this study is to determine the 99th upper-reference limit (URL) for cardiac troponin T (cTnT) in Italian apparently healthy subjects. METHODS: The reference population was selected from 5 cities: Bolzano (n=290), Milano (CAMELIA-Study, n=287), Montignoso (MEHLP-Study, n=306), Pisa (n=182), and Reggio Calabria (MAREA-Study, n=535). Subjects having cardiac/systemic acute/chronic diseases were excluded. Participants to MEHLP project underwent cardiac imaging investigation. High-sensitive cTnT was measured with Cobas-e411 (Roche Diagnostics). RESULTS: We enrolled 1600 healthy subjects [54.6% males; age range 10-90years; mean (SD): 36.4 (21.2) years], including 34.6% aged <20years, 54.5% between 20 and 64years, and 10.9% over 65years. In the youngest the 99th URL was 10.9ng/L in males and 6.8ng/L in females; in adults 23.2ng/L and 10.2ng/L; and in elderly 36.8ng/L and 28.6ng/L. After the exclusion of outliers the 99th URL values were significantly decreased (P<0.05) in particular those of the oldest (13.8ng/L and 14ng/L). MEHLP participants were divided in healthy and asymptomatic, according to known cardiovascular risk factors (HDL, LDL, glucose, C-reactive protein): the 99th URL of cTnT values of these subgroups was significantly different (19.5 vs. 22.7, P<0.05). CONCLUSIONS: 99th URL of cTnT values was strongly affected by age, gender, selection of subjects and the statistical evaluation of outliers.