1,720,971 research outputs found
Endothelial dysfunction or dysfunctions? Identification of three different FMD responses in males with type 2 diabetes.
No full textEndothelial function is widely evaluated by vasodilatation of the brachial artery
induced by ischemia (flow-mediated vasodilatation, FMD). The function of the
endothelium, in this setting, is to sense wall shear stress (WSS) increase and to
release vasodilators. Following current guidelines FMD is measured 50-60s after
ischemia. It is not known whether this lapse of time is sufficient to observe
maximal vasodilatation, especially in diseased subjects. Sixty-six subjects with
type 2 diabetes and 30 controls underwent FMD-test. Brachial artery WSS was
measured at rest and during the first 15s after ischemia as index of peripheral
resistances vessels reactivity, and FMD at 50, 120, 180, and 300s after ischemia
as index of conduit vessel function. All controls exhibited increased WSS and
peak FMD at 50s. Among subjects with diabetes three groups were identified based
on the time at which peak FMD occurred. Twenty subjects with diabetes exhibited
peak at 50s (Early FMD), 28 at 2 min (Late FMD), and 18 showed no FMD (Absent
FMD). Peak FMD in Late FMD subgroup was comparable to peak in control subjects
and significantly higher than peak in other subjects with diabetes. The "Absent
FMD" group showed also impaired WSS. The present findings demonstrate that
brachial artery response to ischemia is heterogeneous in type 2 diabetes,
suggesting different mechanisms responsible for FMD alteration in this condition
Body mass index, metabolic syndrome and carotid atherosclerosis.
No full textOBJECTIVE: Body fatness and fat distribution are widely accepted as coronary
heart disease risk factors. In this study, we have evaluated the contribution of
generalized adiposity, assessed by body mass index (BMI), to carotid
atherosclerosis, in participants with or without metabolic syndrome (MetS).
METHODS: We have analysed 840 female and 1002 male participants in a regional
Cardiovascular Disease Prevention Campaign. Blood glucose and lipids were
analysed by standard methods. According to BMI, calculated as weight (in
kilograms)/height (in square metres), participants were divided into normal
weight (BMI <25 kg/m2), overweight (BMI between 25 and 29.9 kg/m2) and obese
(BMI>29.9 kg/m2). Carotid atherosclerosis was evaluated by echo Doppler.
RESULTS: Blood pressure, waist circumference, triglycerides and glucose were
significantly higher, and high-density lipoprotein was lower, in overweight and
obese participants, compared with normal weight. MetS was more frequent among
obese and overweight than normal-weight participants (51.7 vs. 21.5 vs. 9.8%,
respectively). The prevalence of carotid atherosclerosis was 45.29% in
participants with MetS, significantly higher than in participants without MetS
(33.04%, P<0.0001), but it was similar across the three weight categories.
Furthermore, in multiple regression analyses BMI was not significantly associated
with carotid atherosclerosis.
CONCLUSION: The present findings suggest that increasing body weight favours the
clustering of coronary heart disease risk factors. Overweight and obesity,
however, do not independently associate with carotid atherosclerosis
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Lipid-polymer nanoparticles encapsulating curcumin for modulating the vascular deposition of breast cancer cells
No full textVascular adhesion and endothelial transmigration are critical steps in the establishment of distant metastasis by circulating tumor cells (CTCs). Also, vascular inflammation plays a pivotal role in steering CTCs out of the blood stream. Here, long circulating lipid-polymer nanoparticles encapsulating curcumin (NANOCurc) are proposed for modulating the vascular deposition of CTCs. Upon treatment with NANOCurc, the adhesion propensity of highly metastatic breast cancer cells (MDA-MB-231) onto TNF-α stimulated endothelial cells (HUVECs) reduces by ~. 70%, in a capillary flow. Remarkably, the CTCs vascular deposition already reduces up to ~. 50% by treating solely the inflamed HUVECs. The CTCs arrest is mediated by the interaction between ICAM-1 on HUVECs and MUC-1 on cancer cells, and moderate doses of curcumin down-regulate the expression of both molecules. This suggests that NANOCurc could prevent metastasis and limit the progression of the disease by modulating vascular inflammation and impairing the CTCs arrest. From the Clinical Editor: In this novel study, lipid nanoparticles encapsulating curcumin were able to prevent metastasis formation and limited the progression of the disease by modulating vascular inflammation and impairing the circulating tumor cells' arrest as a result of down-regulation of ICAM1 and MUC1 in a highly metastatic breast cancer cell line model. © 2014 Elsevier Inc
Variations on the Author
No full text“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
No full textWe 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
Influence of acute reduction of blood viscosity on endothelial function
No full textBACKGROUND: The relationship between blood viscosity (BV) and endothelial function is rather complex. An increase in BV causes an increase in blood flow resistance, with negative hemodynamic effects; on the other hand, a moderate increase in BV causes an increase in wall stress shear (WSS), and consequent beneficial effects. As a matter of fact, the effect of changes in BV on endothelial function is not yet clear. OBJECTIVES: Aim of the present study was to evaluate in-vivo the effects of the acute reduction in BV on endothelial function, in healthy male subjects. METHODS: Fourteen healthy male blood donors were studied before and 48 hours after blood donation. Blood and plasma viscosity were measured at 37C° with a cone-plate viscometer. Endothelial function was evaluated through flow mediated vasodilation (FMD). RESULTS: Blood viscosity was reduced after blood donation (BV225 (cP) 4.53±0.59 vs.4.18±0.31, p<0.05). FMD 50s after cuff deflation was unchanged: 6.23±3.84 vs. 6.62±4.81, p=NS. The vasodilation, however, lasted longer and the area under the curve of FMD was significantly increased: 8.74±8.77 vs.16.14±8.65, p<0.005. CONCLUSIONS: The present results demonstrate that the acute reduction of BV prolongs vasodilation, without affecting the amount of vasodilatation, possibly as adaptive reaction allowing more time for oxygen release
Intimal plus media thickness of common carotid arterial wall in subjects with hypertension
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