首页期刊导航|Artery research.
期刊信息/Journal information
Artery research.
Elsevier,
Artery research.

Elsevier,

1872-9312

Artery research./Journal Artery research.
正式出版
收录年代

    Effect of angulation and Reynolds number on recirculation at the abdominal aorta-renal artery junction

    Mohammed AmeenuddinMohan An
    8页
    查看更多>>摘要：We investigate the effect of renal artery angle variation and Reynolds number on the probability of formation of atherosclerosis-prone regions at the abdominal aorta-renal artery junction. The Theologically accurate shear-thinning Yeleswarapu model for blood is used to simulate flow in a 3-Dimensional T-junction whose dimensions are those of the human abdominal aorta-renal artery junction. The recirculation length and wall shear stresses are evaluated at the junction for steady, laminar flow using ANSYS FLUENT v14.5. The recirculation length and wall shear stresses are calculated for Reynolds number of 500-1500, and the angle of renal artery (with the horizontal axis) of -20° to +20°. Computational fluid dynamics analysis for the flow conditions used in present study show that the flow recirculation and low wall shear stress regions overlap at the top surface of renal artery downstream of the entrance and at the curved surface of abdominal aorta downstream of the junction, making these regions susceptible to atherosclerosis. Further investigations show that positive angles of renal artery have larger area of recirculation and larger low wall shear stress regions. The recirculation length increases with Reynolds number, and it is maximum when 0 = +20°, and minimum whene = -20°.
      原文链接:
    • NSTL

    A unified mechanism for the water hammer pulse and pulsus bisferiens in severe aortic regurgitation: Insights from wave intensity analysis

    Scott R. AkersJan A. VierendeelsPatrick SegersJulio A. Chirinos...
    4页
    查看更多>>摘要：The carotid bisferiens pulse and the radial water hammer pulse are typical of severe chronic aortic regurgitation. Little is known about the mechanism of these classic cardiovascular signs identified on physical examination. We report the first characterization of these abnormal pulse patterns using wave intensity analysis (WIA) in a patient with severe aortic regurgitation. We demonstrate that an abnormally pronounced forward-traveling mid-systolic suction wave, which immediately followed the initial forward-traveling compression wave from ventricular contraction, explained these pulse patterns. This suction wave likely resulted from blood inertia, arising from a ventricle ejecting a very large stroke volume into a vasodi-lated arterial tree. Our report demonstrates a novel pulsatile hemodynamic mechanism that unifies the pa
      原文链接:
    • NSTL

    Carotid extra-media thickness increases with age, but is not related to arterial stiffness in adults

    Hon Lam ChoiJason S. AuMaureen J. MacDonald
    7页
    查看更多>>摘要：Background: Assessment of carotid artery perivascular adipose tissue through carotid artery extra-media thickness (EMT) ultrasonography has emerged as a novel assessment technique that might contribute unique information to comprehensive evaluations of arterial health. Currently, there is a lack of research examining relationships between EMT and existing measures of arterial health in adults. We investigated the relationships between EMT and established measures of arterial health, including aortic pulse wave velocity (aPWV), carotid distensibility, and intima-media thickness (IMT) in adults.Methods: Using a cross-sectional, observational design, we assessed resting aPWV, carotid distensibility, IMT and EMT in 81 participants who were categorized as younger healthy adults (YHA; n = 51; 25 ± 6 years), older healthy adults (OHA; n = 15; 70 ± 5 years) or older adults with coronary artery disease (CAD; n = 15; 68 ± 9 years).Results: EMT, IMT, and aPWV were higher while carotid distensibility was lower in OHA and CAD versus YHA (P < 0.05). EMT was correlated with age (r = 0.48; P < 0.01), aPWV (r = 0.43; P<0.01), IMT(r = 0.41; P = 0.01), and distensibility (r = -0.37; P< 0.01). Despite significant correlations, EMT was not an independent predictor of any of the traditional measures of arterial health included in this study.Conclusions: The novel finding of this study is that while EMT is elevated in older versus younger adults, in agreement with established indicators of arterial health, it is not a predictive factor in these existing measures. EMT may, however, still have clinical utility as a target for comprehensive monitoring of interventions specifically designed to impact, arterial structure and function.
      原文链接:
    • NSTL

    IL-17 producing CD4 + CD45RO+ T-cells in atherosclerosis express GITR molecule

    Negar BehnamfarMohammad Javad ZibaeenezhadMehrnoosh DoroudchiAtefe Ghamar Talepoor...
    9页
    查看更多>>摘要：Background: Atherosclerosis (AS) is a chronic inflammatory disease of vessel walls associated with infiltration of immune cells which their function is controlled by different co-stimulatory and co-inhibitory receptors. We investigated the expression of co-inhibitory molecules on the memory and effector T-cells in patients with Atherosclerosis. Methods: Patients included 9 hypertensive, dyslipidemic, non-diabetic, non-smoker individuals with the diagnosis of coronary artery disease and controls were 8 normotensive, normoli-pemic, non-diabetic, non-smoker individuals with normal coronary angiography/insignificant coronary artery disease. PBMCs were separated from the blood and memory T-cell subsets as well as the expression of Glucocorticoid-induced tumor necrosis factor receptor (GITR), Programmed Death-1 (PD-1), IL-17A and IFN-gamma were quantified by flowcytometry. Results: CD4+CD45RO+ memory T-cells and CD4+CD45RO- effector T-cells in patients expressed the highest level of GITR molecule. The IL-17 producing memory CD4+CD45RO+ T-cells were enriched in GITR molecule in the patients group (P = 0.03). The increased population of GITR+effector CD4+CD45RO- T-cells in patients, however, did not produce IL-17 (P = 0.03). PD-1 expression on memory T-cells of the patients was higher than the controls and was concomitant with the lack of IFN-gamma expression (P = 0.05). IFN-gamma production by effector T-cells was only seen in the PD-1- population in both groups. Conclusions: We provide data on the expression of GITR molecule on IL-17 producing memory T-cells in patients with CAD. A population of memory T-cells, which expressed PD-1 and were not producing IFN-gamma, also increased in patients' blood. These data suggest the modified pheno-type/function of T-cell subsets in the atherosclerotic inflammation.
      原文链接:
    • NSTL

    Flow-mediated slowing of brachial-radial pulse wave velocity: Methodological aspects and clinical determinants

    Nicholas CauwenberghsYenthel HeyrmanLutgarde ThijsWen-Yi Yang...
    9页
    查看更多>>摘要：Background: Recent studies proposed that deceleration in pulse wave velocity (PWV) following reactive hyperaemia might reflect arterial distensibility and endothelial function. We therefore investigated methodological aspects and clinical determinants of new indexes of flow-mediated slowing (FMS) of PWV in a community-based sample. Methods: In 71 subjects (mean age, 60.3 years; 50.7% women), we continuously assessed brachial-radial PWV using Vicorder? at baseline and after 3-min or 5-min suprasystolic upper-arm cuff occlusion. We calculated the relative change (A) in PWV per each 30 s intervals during 4 min of post-occlusion. We performed stepwise regression analyses to assess determinants of the PWV response. Results: The peak FMS was detected at the first PWV recording obtained after occlusion. Overall, the decline in PWV during hyperaemia was significantly greater after 5-min of occlusion as compared to 3-min (effect sizes for 0-240 s intervals: -1.83% to -9.63%; P < 0.037). PWV declined significantly less with higher age during the 0-60 s post-occlusion intervals (P < 0.0053). On the other hand, after 120 s of post-occlusion, APWV remained significantly lower in subjects with high diastolic blood pressure and oxidized LDL, and in smokers (P < 0.028). Consequently, as compared to healthy reference group, participants with cardiovascular risk factors exhibited a delay in age-adjusted recovery of PWV after 5-min of occlusion (P < 0.039). Conclusions: Our findings confirm the use of a 5-min occlusion time for the assessment of vaso-motor function by FMS. Whereas the early FMS response might deteriorate with ageing, cardiovascular risk factors such as smoking, oxidative stress and hypertension might affect recovery of PWV after reactive hyperaemia.
      原文链接:
    • NSTL

    Vasoreactivity of thoracic aorta in Nigella Sativa supplemented and/or exercise trained rats

    Rabia LatifAl-Asoom Li
    5页
    查看更多>>摘要：Background: Nigella Sativa (NS) induced vasorelaxation of aortic rings upon direct exposure has been documented in literature. This study was conducted to determine whether 8 weeks Nigella Sativa supplementation and/or exercise training may alter vascular sensitivity of rat aorta in normal, healthy rats.Methods: In this Quasi Experimental Study, forty adult male Wistar albino rats were divided equally into 4 groups. One group served as the control (C), whereas the other three groups were Nigella-treated (N; 800 mg/kg Nigella daily orally via a feeding needle), Exercise-trained (Ex: 18 m/min speed, 2 h duration/day at 32 inclination) and Nigella-treated-exercise-trained (N-Ex: received both Nigella and exercise training). After 8 weeks, rats in all four groups were sacrificed. Their aortic rings were2 mounted in the organ bath. Tension in the aortic rings was measured with an isometric force transducer and recorded with a PowerLab data-acquisition system. Norepinephrine-induced aortic contractions in all four groups were compared by one-way analysis of variance (ANOVA).Results: There were statistically insignificant differences in Norepinephrine-induced aortic contractions among all four groups (P value 0.26, 0.18, 0.07, 0.12, 0.58, 0.24, 0.06 with Norepi-nephrineO, 10~(-7), 10~(-6), 10~(-5),10~(-4), 10~(-3), 10~(-2) respectively). Also, no statistical difference was observed in term of body weight, heart weight, left ventricular weight and their indices in all four groups.Conclusion: NS supplementation and exercise training alone or in combination; for 8 weeks' duration, may not alter vascular reactivity in normal healthy rats.
      原文链接:
    • NSTL

    Elevated levels of IL-6 and IL-9 in the sera of patients with AAA do not correspond to their production by peripheral blood mononuclear cells

    Hamid AriaMehdi KalaniHossein HodjatiMehrnoosh Doroudchi...
    10页
    查看更多>>摘要：Background: Abdominal Aortic Aneurysm (AAA) is the stable local dilatation of abdominal aorta. AAA is an inflammatory condition in which cytokines may play a pathogenic role. Methods: Peripheral Blood Mononuclear cells (PBMCs) were isolated from 5 men, with confirmed diagnosis of AAA and aortic dilation greater than 5.5 cm, and 5 men with normal/ insignificant angiography, CT-Scan and Ultrasonography results. The supernatant of PBMCs, rested overnight in RPMI containing 10%-FBS, removed to measure IL-2, IL-4, IL-5, IL-6, IL-9, IL-10, IL-13, IL-17A, IL-17F, IL-21, IL-22, IFN-gamma and TNF-alpha using a commercial fluorescent-labeled bead assay. Results: The mean serum IL-6 and IL-9 levels were significantly higher in patients than controls (P = 0.007 and P = 0.007, respectively). PBMCs from patients produced lower levels of IL-6 and IL-9 compared to controls but the differences were not significant. While serum TNF-alpha level was not different between groups, its production by PBMCs of patients was significantly lower than controls (P = 0.047). The mean serum levels of IL-10 and IFN-gamma in patients were marginally higher than controls (P = 0.055, P = 0.055, respectively). Mean serum IL-2 level was not different between the groups but its production by PBMCs of patients was significantly higher than the control group (P = 0.047). Conclusions: Our study showed alteration in the levels of cytokines from inflammatory, Th1, Th2 and Th17 subtypes in the sera of patients with AAA. The production of IL-6, IL-9, IFN-gamma and IL-10, however, was not solely attributed to the PBMCs. Therefore, participation of other cells in the tissue or blood should be considered in their production.
      原文链接:
    • NSTL

    Impact of leg heating on central hemodynamics in postmenopausal women

    Keisei KosakiJun SugawaraAsako Zempo-MiyakiSeiji Maeda...
    5页
    查看更多>>摘要：Background: The determinants responsible for increasing central pressure augmentation, a strong risk factor for cardiovascular disease, remain highly controversial. The aim of this study was to determine the contribution of the impedance mismatch between central and leg arteries on central pressure augmentation. Thus, we investigated whether central pressure augmentation is influenced by manipulation of central-to-leg arterial stiffness mismatch by an acute leg heating.Methods: Nineteen postmenopausal women underwent the warmth stimulation on both lower legs (20 min of exposure to far infra-red radiation at 43-45 °C followed by retaining warmth by a blanket for 30 min). Central (aortic) hemodynamic measures were obtained from applanation tonometrically-radial arterial pressure waveforms via the validated general transfer function. Results: The leg heating decreased only the leg pulse wave velocity. And thus, the central-to-leg arterial stiffness was changed from positive to negative; however, any central (aortic) hemodynamic measures including reflected wave amplitude, aortic blood pressure, and augmentation index, were not changed significantly.Conclusions: Our results suggest that the acute bout of leg heating induces the less of central-to-leg arterial stiffness mismatch but not influence central pressure augmentation in postmenopausal women.
      原文链接:
    • NSTL

    The clinical importance of exercise blood pressure

    Martin G. Schultz
    5页
    查看更多>>摘要：Clinical exercise stress testing is a common medical test performed in cardiology and exercise physiology clinics the world over. Measurement of blood pressure (BP) during testing is mandated. Whilst systolic BP should normally rise with incremental exercise, and diastolic BP remains relatively stable, abnormal responses can occur. Low BPor'exercise hypotension' isaknown signal of underlying cardiovascular disease and sign of poor prognosis. On the other hand, observational evidence suggests an exaggerated BP response is also associated with heightened cardiovascular disease risk. Historically, research has focused on the BP response to peak or maximum exercise intensities. However, exaggerated BP during submaximal exercise (light-to-moderate intensity) may expose the presence of high BP otherwise not detected by traditional resting measurement in the clinic. Exaggerated exercise BP is related to subclinical cardiovascular disease risk markers such as raised arterial stiffness and impaired cardiac structure and function. The mechanisms underlying such associations are complex, but physiological insight has been gained from studying changes in arterial haemodynamics in response to dynamic exercise. Similarly, there are several known modifiers of the exercise BP response, including age, disease status and aerobic capacity. An area of continued focus is to establish if modifiers, such as aerobic capacity, also modify associations between exercise BP and clinical outcomes throughout the life-course. Future work is also directed towards filling a crucial evidence gap, providing population-based thresholds of exercise BP that are associated with acute and longer-term outcomes. This should pave the way for pragmatic research aimed towards enhancing the clinical use of exercise BP.
      原文链接:
    • NSTL

    Stiff vessels approached in a flexible way: Advancing quantification and interpretation of arterial stiffness

    Bart Spronck
    6页
    查看更多>>摘要：Introduction: Although pulse wave velocity (PWV), a proxy of arterial stiffness, is a strong predictor of cardiovascular complications, it is confounded by blood pressure (BP) and heart rate at the time of examination. Furthermore, establishing whether an artery behaves stiffer or less stiff does not inform a clinician on the cause of the stiffening. Quantification of arterial stiffness: This paper focuses on BP as a confounder of PWV. We developed a method to patient-specifically determine the dependence of PWV on BP - on average 1 m/s per 10 mmHg diastolic BP - and used it to disentangle BP-dependent and -independent stiffening in hypertension and cancer patients. We furthermore showed that the so-called cardio-ankle vascular index (CAVI) - a measure deemed BP-independent - shows a residual BP-dependence that is readily correctable using a modified equation (CAVI_0). Both developed methods are directly applicable to clinical measurements in individual patients. Interpretation of arterial stiffness: We developed a computer modelling procedure to disentangle contributions of the individual wall components - collagen, elastin, and smooth muscle - to arterial stiffening as observed in patients. Our model-based approach shows that with ageing, the biomechanical phenotype shifts from elastin-dominated to collagen-dominated load bearing.Model-based assessment of arterial wall mechanics provides a promising tool to further improve interpretation of arterial stiffness measurements in patients. Further development of such methodology applied to various mouse models may improve the understanding and interpretation of arterial stiffening in ageing and disease.
      原文链接:
    • NSTL