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Sample records for human arterial wall

  1. Passive cigarette smoking induces inflammatory injury in human arterial walls

    Institute of Scientific and Technical Information of China (English)

    ZOU Ni; HONG Jiang; DAI Qiu-yan

    2009-01-01

    Background Epidemiological studies have shown that both active and passive cigarette smoking increase the risk of atherosclerosis. But very little is known about the biological processes induced by passive cigarette smoking that contribute to atheresclerosis. We observe the expression of a few of biological and inflammatory markers in human arterial walls in vitro which were treated with the second-hand smoke solution (sidestream whole, SSW), and discuss the possible mechanism of inflammatory injury induced by second-hand smoke.Methods The biological markers (platelet endothelial cell adhesion molecule-1, PECAM-1; α-smooth muscle actin, α-SMA; collagen Ⅳ, Col Ⅳ) and inflammatory markers (vascular cell adhesion molecule-1, VCAM-1; monocyte chemoattractant protein-1, MCP-1; interleukin-8, IL-8) of human aortal wall were tested by immunofluorescence staining. The levels of MCP-1 and IL-8 mRNA expression were detected by reverse transcription-polymerase chain reaction (RT-PCR).Results No distinct difference was observed between SSW and the control group on the expression of biological markers as assessed by the light microscope. But the inflammatory markers VCAM-1, MCP-1 and IL-8 on the subendothelial layer and smooth muscle cell layers, which are near the endothelium of arterial wall, were strongly stained in the SSW group compared with the control group. Their fluorescence intensities in the 1:40 SSW group (VCAM-1: 0.35±0.04, MCP-1: 0.34±0.05, IL-8: 0.37±0.05) and the 1:20 SSW group (VCAM-1: 0.40±0.04, MCP-1: 0.52±0.09, IL-8: 0.51±0.07) were significantly stronger than the control group (VCAM-1: 0.12±0.04, MCP-1: 0.06±0.02, IL-8: 0.24±0.03) by semi-quantitative analysis of immunofluorescence (P <0.001 vs control). MCP-1 mRNA expression in the 1:40 SSW (0.15±0.04) and the 1:20 SSW (0.19±0.06) group was significantly higher than in the control group (0.09±0.03) (P <0.05, P <0.01 vs control); IL-8 mRNA expression in the 1:40 SSW (0.64±0.12) and 1

  2. Impact of exercise training on arterial wall thickness in humans.

    NARCIS (Netherlands)

    Thijssen, D.H.J.; Cable, N.T.; Green, D.J.

    2012-01-01

    Thickening of the carotid artery wall has been adopted as a surrogate marker of pre-clinical atherosclerosis, which is strongly related to increased cardiovascular risk. The cardioprotective effects of exercise training, including direct effects on vascular function and lumen dimension, have been co

  3. Triptans induce vasoconstriction of human arteries and veins from the thoracic wall

    DEFF Research Database (Denmark)

    Wackenfors, Angelica; Jarvius, Malin; Ingemansson, Richard;

    2005-01-01

    A common side effect of migraine treatment with triptans is chest symptoms. The origin of these symptoms is not known. The aim of the present study was to examine the vasocontractile effect of triptans in human arteries and veins from the thoracic wall and in coronary artery bypass grafts. In vitro...... detected by real-time PCR in all blood vessels studied. In conclusion, triptans induce vasoconstriction in arteries and veins from the thoracic wall, most likely by activation of 5-HT1B receptors. This response could be observed in only 38% to 57% of the patients, which may provide an explanation for why...

  4. Remnant Cholesterol Elicits Arterial Wall Inflammation and a Multilevel Cellular Immune Response in Humans.

    Science.gov (United States)

    Bernelot Moens, Sophie J; Verweij, Simone L; Schnitzler, Johan G; Stiekema, Lotte C A; Bos, Merijn; Langsted, Anne; Kuijk, Carlijn; Bekkering, Siroon; Voermans, Carlijn; Verberne, Hein J; Nordestgaard, Børge G; Stroes, Erik S G; Kroon, Jeffrey

    2017-05-01

    Mendelian randomization studies revealed a causal role for remnant cholesterol in cardiovascular disease. Remnant particles accumulate in the arterial wall, potentially propagating local and systemic inflammation. We evaluated the impact of remnant cholesterol on arterial wall inflammation, circulating monocytes, and bone marrow in patients with familial dysbetalipoproteinemia (FD). Arterial wall inflammation and bone marrow activity were measured using (18)F-FDG PET/CT. Monocyte phenotype was assessed with flow cytometry. The correlation between remnant levels and hematopoietic activity was validated in the CGPS (Copenhagen General Population Study). We found a 1.2-fold increase of (18)F-FDG uptake in the arterial wall in patients with FD (n=17, age 60±8 years, remnant cholesterol: 3.26 [2.07-5.71]) compared with controls (n=17, age 61±8 years, remnant cholesterol 0.29 [0.27-0.40]; Pcholesterol accumulates in human hematopoietic stem and progenitor cells coinciding with myeloid skewing. Patients with FD have increased arterial wall and cellular inflammation. These findings imply an important inflammatory component to the atherogenicity of remnant cholesterol, contributing to the increased cardiovascular disease risk in patients with FD. © 2017 American Heart Association, Inc.

  5. Regional calcium distribution and ultrasound images of the vessel wall in human carotid arteries

    Science.gov (United States)

    Szikszai, Z.; Kertész, Zs.; Uzonyi, I.; Szíki, G. Á.; Magyar, M. T.; Molnár, S.; Ida, Y.; Csiba, L.

    2005-04-01

    Arterial calcification can take place at two sites in the vessel wall: the intima and the media. Intimal calcification occurs exclusively within atherosclerotic plaques, while medial calcification may develop independently. Extensive calcified plaques in the carotid arteries can be easily detected by B-mode ultrasonic imaging. The calcium content might correlate with the ultrasound reflectance of the vessel wall, and could be a surrogate marker for arteriosclerosis. In this study, segments of human carotid arteries collected at autopsy were examined by ultrasonography in vitro and calcium distributional maps of sections from the same segments were determined by particle induced X-ray emission. Our aim was to make a first step towards investigating the relationship between the calcium distributional maps and the respective ultrasound images.

  6. ON WALL SHEAR STRESS OF ARTERY

    Institute of Scientific and Technical Information of China (English)

    Liu Zhao-rong; Liu Bao-yu; Qin Kai-rong

    2003-01-01

    In this paper, a method was proposed that the wall shear stress of artery could be determined by measuring the centerline axial velocity and radial motion of arterial wall simultaneously.The method is simple in application and can get higher precision when it is used to determine the shear stress of arterial wall in vivo.As an example, the shear stress distribution in periodic oscillatory flow of human carotid was calculated and discussed.The computed results show that the shear stress distribution at any given instant is almost uniform and will be zero at the centerline and tends to maximum at the vessel wall.

  7. Plaque components affect wall stress in stented human carotid artery: A numerical study

    Science.gov (United States)

    Fan, Zhen-Min; Liu, Xiao; Du, Cheng-Fei; Sun, An-Qiang; Zhang, Nan; Fan, Zhan-Ming; Fan, Yu-Bo; Deng, Xiao-Yan

    2016-09-01

    Carotid artery stenting presents challenges of in-stent restenosis and late thrombosis, which are caused primarily by alterations in the mechanical environment of the artery after stent implantation. The present study constructed patient-specific carotid arterial bifurcation models with lipid pools and calcified components based on magnetic resonance imaging. We numerically analyzed the effects of multicomponent plaques on the distributions of von Mises stresses (VMSs) in the patient-specific models after stenting. The results showed that when a stent was deployed, the large soft lipid pool in atherosclerotic plaques cushioned the host artery and reduced the stress within the arterial wall; however, this resulted in a sharp increase of VMS in the fibrous cap. When compared with the lipid pool, the presence of the calcified components led to slightly increased stresses on the luminal surface. However, when a calcification was located close to the luminal surface of the host artery and the stenosis, the local VMS was elevated. Overall, compared with calcified components, large lipid pools severely damaged the host artery after stenting. Furthermore, damage due to the calcified component may depend on location.

  8. Plaque components affect wall stress in stented human carotid artery:A numerical study

    Institute of Scientific and Technical Information of China (English)

    Zhen-Min Fan; Xiao Liu; Cheng-Fei Du; An-Qiang Sun; Nan Zhang; Zhan-Ming Fan; Yu-Bo Fan; Xiao-Yan Deng

    2016-01-01

    Carotid artery stenting presents challenges of in-stent restenosis and late thrombosis, which are caused primarily by alterations in the mechanical environment of the artery after stent implantation. The present study con-structed patient-specific carotid arterial bifurcation models with lipid pools and calcified components based on magnetic resonance imaging. We numerically analyzed the effects of multicomponent plaques on the distributions of von Mises stresses (VMSs) in the patient-specific models after stenting. The results showed that when a stent was deployed, the large soft lipid pool in atherosclerotic plaques cushioned the host artery and reduced the stress within the arterial wall;how-ever, this resulted in a sharp increase of VMS in the fibrous cap. When compared with the lipid pool, the presence of the calcified components led to slightly increased stresses on the luminal surface. However, when a calcification was located close to the luminal surface of the host artery and the stenosis, the local VMS was elevated. Overall, compared with calcified components, large lipid pools severely dam-aged the host artery after stenting. Furthermore, damage due to the calcified component may depend on location.

  9. Quantifying [F-18]fluorodeoxyglucose uptake in the arterial wall

    DEFF Research Database (Denmark)

    Blomberg, Björn Alexander; Bashyam, A.; Ramachandran, A.

    2015-01-01

    Purpose The human arterial wall is smaller than the spatial resolution of current positron emission tomographs. Therefore, partial volume effects should be considered when quantifying arterial wall F-18-FDG uptake. We evaluated the impact of a novel method for partial volume effect (PVE) correcti...

  10. Determination of arterial wall shear stress

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The arteries can remodel their structure and function to adapt themselves to the mechanical environment. In various factors that lead to vascular remodeling, the shear stress on the arterial wall induced by the blood flow is of great importance. However, there are many technique difficulties in measuring the wall shear stress directly at present. In this paper, through analyzing the pulsatile blood flow in arteries, a method has been proposed that can determine the wall shear stress quantitatively by measuring the velocity on the arterial axis, and that provides a necessary means to discuss the influence of arterial wall shear stress on vascular remodeling.

  11. Markers of inflammation collocate with increased wall stress in human coronary arterial plaque.

    Science.gov (United States)

    Hallow, Karen Melissa; Taylor, W Robert; Rachev, Alexander; Vito, Raymond Peter

    2009-12-01

    In this study, we hypothesized that spatial relationships exist between the local mechanical environment and inflammatory marker expression in atherosclerotic plaques, and that these relationships are plaque-progression dependent. Histologic cross-sections were collected at regular intervals along the length of diseased human coronary arteries and classified as early, intermediate, advanced, or mature based on their morphological features. For each cross-section, the spatial distribution of stress was determined using a 2D heterogeneous finite element model, and the corresponding distribution of selected inflammatory markers (macrophages, matrix metalloproteinase-1 [MMP-1], and nuclear factor-kappa B [NF-κB]) were determined immunohistochemically. We found a monotonic spatial relationship between mechanical stress and activated NF-κB that was consistent in all stages of plaque progression. We also identified progression-dependent relationships between stress and both macrophage presence and MMP-1 expression. These findings add to our understanding of the role of mechanical stress in stimulating the inflammatory response, and help explain how mechanical factors may regulate complex biological changes in remodeling.

  12. Determination of arterial wall shear stress

    Institute of Scientific and Technical Information of China (English)

    LIU; Zhaorong

    2001-01-01

    [1]Langille, B. L., 7Donnell, F., Reductions in arterial diameter produced by chronic decreases in blood flow are endothelium-dependent, Science, 1986, 231: 405—407.[2]Langer, R., Vacanti, J. P., Tissue engineering, Science, 1993, 260: 920—926.[3]Kamiya, A., Togawa, T., Adaptive regulation of wall shear stress to flow change in the canine carotid artery, Am. J. Physiol. (Heart Circ. Physiol.), 1980, 239: H14—H21.[4]Fung, Y. C., Biomechanics: Motion, Flow, Stress, and Growth, New York: Springer-Verlag, 1990.[5]Liu, S. Q., Biomechanical basis of vascular tissue engineering, Critical Reviews in Biomedical Engineering, 1999, 27: 75—148.[6]Ando, J., Kamiya, A., Blood flow and vascular endothelium cell function, Frontiers Med. Biological Eng., 1993, 5: 245—264.[7]Ku, D. N., Giddens, D. P., Zarins, D. K. et al., Pulsatile flow and atherosclerosis in the human carotid bifurcation-positive correlation between plaque location and low and oscillating shear stress, Atherosclerosis, 1985, 5: 293—302.[8]Liu Zhaorong, Li Xixi, Theory and Method on Hemodynamics (in Chinese), Shanghai: Fudan University Press, 1997.

  13. Impaired Arterial Elasticity Identified by Pulse Waveform Analysis as a Marker for Vascular Wall Damage in Humans With Aging and Hypertension

    Institute of Scientific and Technical Information of China (English)

    Wang Yan; Tao Jun; Tu Chang; Yang Zhen; Xu Mingguo; Wang Jiemei; Jin Yafei; Ma Hong

    2005-01-01

    Objectives Cardiovascular risk factors lead to pathogenesis of atherosclerosis and its clinical events by impairing vascular wall. Endothelial dysfunction is the earliest marker for vascular wall injuries. Development of new method to detect early vascular wall damage has an important clinical implication for the prevention and treatment of cardiovascular diseases. Therefore, the present study was performed to evaluate effect of aging and hypertension, two independent risk factors for cardiovascular diseases, on arterial elasticity by using pulse waveform analysis and investigate whether the changes in arterial elasticity can be used as a risk marker for vascular structural and functional abnormalities. Methods Using modified Windkessel model of the circulation and pulse waveform analysis,C 1 large artery and C2 small artery elasticity indices of 204 Chinese normal healthy subjects ( age 15-80years) and 46 Chinese essential hypertensive patients (age 35-70 years) were measured. Age- and hypertension-related arterial elasticity changes were examined. Results C1 large artery and C2 small artery elasticity indices were reduced with advancing age in healthy subjects. C1 large artery and C2 small artery elasticity indices were negatively correlated with age (r=-0.628, P<0.001; r=-0.595, P<0.001). C1 large artery and C2 small artery elasticity indices in patients with essential hypertension compared with the agematched healthy subjects were (9.31±3.85 ml/mm Hg x 10 versus 15.13±4.14 ml/mmHg x 10, P<0.001) and (3.57± 1.62 ml/mm Hg x 100 versus 7.89±2.91 ml/mmHg ×100 P <0.001), respectively, and were significantly lower than the corresponding healthy subjects. There were negative association between C1large artery and C2 small artery elasticity indices and systolic blood pressure (r=-0.37, P<0.05; r=-0.39,P<0.05) and pulse pressure (r=-0.39, P<0.05; r=0.43,P<0.05) in patients with essential hypertension.Conclusions Advancing age and essential

  14. Isotropy and anisotropy of the arterial wall.

    Science.gov (United States)

    Weizsacker, H W; Pinto, J G

    1988-01-01

    The passive biomechanical response of intact cylindrical rat carotid arteries is studied in vitro and compared with the mechanical response of rubber tubes. Using true stress and natural strain in the definition of the incremental modulus of elasticity, the tissue wall properties are analyzed over wide ranges of simultaneous circumferential and longitudinal deformations. The type of loading chosen is 'physiological' i.e. symmetric: the cylindrical segments are subjected to internal pressure and axial prestretch without torsion or shear. Several aspects pertaining to the choice of parameters characterizing the material are discussed and the analysis pertaining to the deformational behavior of a hypothetical compliant tube with Hookean wall material is presented. The experimental results show that while rubber response can be adequately represented as linearly elastic and isotropic, the overall response of vascular tissue is highly non-linear and anisotropic. However, for states of deformation that occur in vivo, the elasticity of arteries is quite similar to that of rubber tubes and as such the arterial wall may be viewed as incrementally isotropic for the range of deformations that occur in vivo.

  15. Wall shear stress evolution in carotid artery bifurcation

    Science.gov (United States)

    Bernad, S. I.; Bosioc, A. I.; Totorean, A. F.; Petre, I.; Bernad, E. S.

    2017-07-01

    The steady flow in an anatomically realistic human carotid bifurcation was simulated numerically. Main parameters such as wall shear stress (WSS), velocity profiles and pressure distributions are investigated in the carotid artery, namely in bifurcation and sinusoidal enlargement regions. Flow in the carotid sinus is dominated by a single secondary vortex motion accompanied by a strong helical flow. This type of flow is induced primarily by the curvature and asymmetry of the in vivo geometry. Low wall shear stress concentration occurs at both the anterior and posterior aspects of the proximal internal bulb.

  16. Oxygen transfer in human carotid artery bifurcation

    Institute of Scientific and Technical Information of China (English)

    Z.G.Zhang; Y.B.Fan; X.Y.Deng

    2007-01-01

    Arterial bifurcations are places where blood flow may be disturbed and slow recirculation flow may occur.To reveal the correlation between local oxygen transfer and atherogenesis, a finite element method was employed to simulate the blood flow and the oxygen transfer in the human carotid artery bifurcation. Under steady-state flow conditions, the numerical simulation demonstrated a variation in local oxygen transfer at the bifurcation, showing that the convective condition in the disturbed flow region may produce uneven local oxygen transfer at the blood/wall interface.The disturbed blood flow with formation of slow eddies in the carotid sinus resulted in a depression in oxygen supply to the arterial wall at the entry of the sinus, which in turn may lead to an atherogenic response of the arterial wall, and contribute to the development of atherosclerotic stenosis there.

  17. Wall shear stress in intracranial aneurysms and adjacent arteries

    Institute of Scientific and Technical Information of China (English)

    Fuyu Wang; Bainan Xu; Zhenghui Sun; Chen Wu; Xiaojun Zhang

    2013-01-01

    Hemodynamic parameters play an important role in aneurysm formation and growth. However, it is difficult to directly observe a rapidly growing de novo aneurysm in a patient. To investigate possible associations between hemodynamic parameters and the formation and growth of intracranial aneurysms, the present study constructed a computational model of a case with an internal carotid artery aneurysm and an anterior communicating artery aneurysm, based on the CT angiography findings of a patient. To simulate the formation of the anterior communicating artery aneurysm and the growth of the internal carotid artery aneurysm, we then constructed a model that virtually removed the anterior communicating artery aneurysm, and a further two models that also progressively decreased the size of the internal carotid artery aneurysm. Computational simulations of the fluid dynamics of the four models were performed under pulsatile flow conditions, and wall shear stress was compared among the different models. In the three aneurysm growth models, increasing size of the aneurysm was associated with an increased area of low wall shear stress, a significant decrease in wall shear stress at the dome of the aneurysm, and a significant change in the wall shear stress of the parent artery. The wall shear stress of the anterior communicating artery remained low, and was significantly lower than the wall shear stress at the bifurcation of the internal carotid artery or the bifurcation of the middle cerebral artery. After formation of the anterior communicating artery aneurysm, the wall shear stress at the dome of the internal carotid artery aneurysm increased significantly, and the wall shear stress in the upstream arteries also changed significantly. These findings indicate that low wall shear stress may be associated with the initiation and growth of aneurysms, and that aneurysm formation and growth may influence hemodynamic parameters in the local and adjacent arteries.

  18. Construction and histological analysis of a 3D human arterial wall model containing vasa vasorum using a layer-by-layer technique.

    Science.gov (United States)

    Shima, Fumiaki; Narita, Hirokazu; Hiura, Ayami; Shimoda, Hiroshi; Akashi, Mitsuru

    2017-03-01

    There is considerable global demand for three-dimensional (3D) functional tissues which mimic our native organs and tissues for use as in vitro drug screening systems and in regenerative medicine. In particular, there has been an increasing number of patients who suffer from arterial diseases such as arteriosclerosis. As such, in vitro 3D arterial wall models that can evaluate the effects of novel medicines and a novel artificial graft for the treatment are required. In our previous study, we reported the rapid construction of 3D tissues by employing a layer-by-layer (LbL) technique and revealed their potential applications in the pharmaceutical fields and tissue engineering. In this study, we successfully constructed a 3D arterial wall model containing vasa vasorum by employing a LbL technique for the first time. The cells were coated with extracellular matrix nanofilms and seeded into a culture insert using a cell accumulation method. This model had a three-layered hierarchical structure: a fibroblast layer, a smooth muscle layer, and an endothelial layer, which resembled the native arterial wall. Our method could introduce vasa vasorum into a fibroblast layer in vitro and the 3D arterial wall model showed barrier function which was evaluated by immunostaining and transendothelial electrical resistance measurement. Furthermore, electron microscopy observations revealed that the vasa vasorum was composed of single-layered endothelial cells, and the endothelial tubes were surrounded by the basal lamina, which are known to promote maturation and stabilization in native blood capillaries. These models should be useful for tissue engineering, regenerative medicine, and pharmaceutical applications. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 814-823, 2017.

  19. Structurally Motivated Models of the Arterial Wall Tissue

    Science.gov (United States)

    Taghizadeh, Hadi; Shadpour, Mohammad Tafazzoli

    2013-05-01

    Mechanical characteristics of soft biological tissues mostly depend on their hierarchy at different scales from nano- to macro-structure. It is shown that arterial wall tissue is highly sensitive to its mechanical environment and any alteration in mechanical factors such as blood pressure, triggers physio- pathological processes within arterial wall. Quantification of these mechanical properties will provide us with deeper insights of ongoing biological events. In this context, mechanical contributions of wall constituents in health and diseases are of growing interest. Hence, this review is concerned with mechanical models of arterial wall tissue with a focus on microstructurally motivated representations.

  20. Arterial Wall Properties and Womersley Flow in Fabry Disease

    Directory of Open Access Journals (Sweden)

    Dimitriadis Emilios

    2002-01-01

    Full Text Available Abstract Background Fabry disease is an X-linked recessive lysosomal storage disease resulting in the cellular accumulation of globotriaosylceramide particularly globotriaosylceramide. The disease is characterized by a dilated vasculopathy with arterial ectasia in muscular arteries and arterioles. Previous venous plethysomographic studies suggest enhanced endothelium-dependent vasodilation in Fabry disease indicating a functional abnormality of resistance vessels. Methods We examined the mechanical properties of the radial artery in Fabry disease, a typical fibro-muscular artery. Eight control subjects and seven patients with Fabry disease had a right brachial arterial line placed allowing real time recording of intra-arterial blood pressure. Real time B-mode ultrasound recordings of the right radial artery were obtained simultaneously allowing calculation of the vessel wall internal and external diameter, the incremental Young's modulus and arterial wall thickness. By simultaneously measurement of the distal index finger-pulse oximetry the pulse wave speed was calculated. From the wave speed and the internal radial artery diameter the volume flow was calculated by Womersley analysis following truncation of the late diastolic phase. Results No significant difference was found between Fabry patients and controls for internal or external arterial diameters, the incremental Young's modulus, the arterial wall thickness, the pulse wave speed and the basal radial artery blood flow. Further, no significant difference was found for the radial artery blood flow in response to intra-arterial acetylcholine or sodium nitroprusside. Both drugs however, elevated the mean arterial flow. Conclusions The current study suggests that no structural or mechanical abnormality exists in the vessel wall of fibro-muscular arteries in Fabry disease. This may indicate that a functional abnormality downstream to the conductance vessels is the dominant feature in

  1. An object-oriented modelling framework for the arterial wall.

    Science.gov (United States)

    Balaguera, M I; Briceño, J C; Glazier, J A

    2010-02-01

    An object-oriented modelling framework for the arterial wall is presented. The novelty of the framework is the possibility to generate customizable artery models, taking advantage of imaging technology. In our knowledge, this is the first object-oriented modelling framework for the arterial wall. Existing models do not allow close structural mapping with arterial microstructure as in the object-oriented framework. In the implemented model, passive behaviour of the arterial wall was considered and the tunica adventitia was the objective system. As verification, a model of an arterial segment was generated. In order to simulate its deformation, a matrix structural mechanics simulator was implemented. Two simulations were conducted, one for an axial loading test and other for a pressure-volume test. Each simulation began with a sensitivity analysis in order to determinate the best parameter combination and to compare the results with analogue controls. In both cases, the simulated results closely reproduced qualitatively and quantitatively the analogue control plots.

  2. In vivo hypertensive arterial wall uptake of radiolabeled liposomes

    Energy Technology Data Exchange (ETDEWEB)

    Hodis, H.N.; Amartey, J.K.; Crawford, D.W.; Wickham, E.; Blankenhorn, D.H. (Univ. of Southern California School of Medicine, Los Angeles (USA))

    1990-06-01

    Using five sham-operated and seven aortic coarctation-induced hypertensive New Zealand White rabbits intravenously injected with neutral small unilamellar vesicles loaded with (111In)nitrilotriacetic acid, we demonstrated in vivo that the normal aortic arterial wall participates in liposome uptake and that this uptake is increased in the hypertensive aortic wall by approximately threefold (p less than or equal to 0.0001). Among the three regions examined, aortic arch, thoracic aorta, and lower abdominal aorta, the difference in uptake between the normotensive and hypertensive arterial walls was significantly different, p less than or equal to 0.05, p less than or equal to 0.0001, and p less than 0.05, respectively. The uptake by the different regions of the hypertensive arterial wall is consistent with the pathological changes present in these areas. Furthermore, the extent of liposome uptake by the aortic wall is strongly correlated with the height of the blood pressure (r = 0.85, p = 0.001, n = 11). We conclude that neutral small unilamellar liposomes can be used to carry agents into the arterial wall in vivo in the study of hypertensive vascular disease and could be especially useful for the delivery of pharmacologically or biologically active agents that would otherwise be inactivated within the circulation or are impermeable to the arterial wall.

  3. Sonographic assessment of splanchnic arteries and the bowel wall

    Energy Technology Data Exchange (ETDEWEB)

    Dietrich, C.F. [Medical Department II, Caritas-Krankenhaus, Uhlandstr. 7, D-97980 Bad Mergentheim (Germany)], E-mail: Christoph.dietrich@ckbm.de; Jedrzejczyk, M.; Ignee, A. [Medical Department II, Caritas-Krankenhaus, Uhlandstr. 7, D-97980 Bad Mergentheim (Germany)

    2007-11-15

    The intestinal wall can be visualized using high resolution transabdominal ultrasound. The normal intestinal wall thickness in the terminal ileum, cecum, and right and left colon is <2 mm when examined with graded compression. It is important to appreciate that a contracted intestinal segment can be misinterpreted as a thickened wall. Vascularisation can be mainly displayed in the second hyperechoic layer (submucosal layer) as well as vessels penetrating the muscularis propria. Imaging of the gastrointestinal wall is dependent on the experience of the examiner as well dependent on the equipment used. Acute or chronic inflammation of the intestinal wall is accompanied by increased perfusion of the mesentery, which can be displayed non-quantitatively with colour duplex. In contrast, ischemia is characterised by hypoperfusion of the mesenteric arteries and the bowel wall. The most promising sonographic approach in assessing splanchnic arteries and the bowel wall is combining the analysis of superior and inferior mesenteric inflow by pulsed Doppler scanning (systolic and diastolic velocities, resistance index) with the end-organ vascularity by colour Doppler imaging diminishing the influence of examination technique only displaying bowel wall vascularity. Colour Doppler imaging has been described as helpful in a variety of gastrointestinal disorders, particularly in patients with Crohn's disease, celiac disease, mesenteric artery stenosis and other ischemic gastrointestinal diseases, graft versus host disease and hemorrhagic segmental colitis.

  4. Effects of the flexibility of the arterial wall on the wall shear stresses and wall tension in Abdominal Aortic Aneurysms.

    Science.gov (United States)

    Salsac, Anne-Virginie; Fernandez, Miguel; Chomaz, Jean-Marc

    2005-11-01

    As an abdominal aortic aneurysm develops, large changes occur in the composition and structure of the arterial wall, which result in its stiffening. So far, most studies, whether experimental or numerical, have been conducted assuming the walls to be rigid. A numerical simulation of the fluid structure interactions is performed in different models of aneurysms in order to analyze the effects that the wall compliance might have on the flow topology. Both symmetric and non-symmetric models of aneurysms are considered, all idealistic in shape. The wall mechanical properties are varied in order to simulate the progressive stiffening of the walls. The spatial and temporal distributions of wall tension are calculated for the different values of the wall elasticity and compared to the results for the rigid walls. In the case of rigid walls, the calculation of the wall shear stresses and pressure compare very well with experimental results.

  5. Simulated lipoprotein transport in the wall of branched arteries.

    Science.gov (United States)

    Darbeau, M Z; Lutz, R J; Collins, W E

    2000-01-01

    Study of arterial blood flow dynamics improves our understanding of the development of cardiovascular diseases such as atherosclerosis. The transport and accumulation of macromolecules in the arterial wall can be influenced by local fluid mechanics. We used numeric simulations to investigate such transport in a T-junction model. Presumably an in vitro experiment would consist of gel segments inserted in the walls of a mechanical flow T-junction model near branch points where separation and recirculation zones are expected. The transport of low density lipoprotein (LDL) was investigated theoretically at these sites in a two dimensional numeric T-branch model. In the numeric model, the hydraulic conductivity of the porous gel wall segments was varied for a fixed species diffusivity to provide simulations with wall transmural Peclet numbers ranging from 0.3 to 30. Steady state flow patterns in the lumen of the two dimensional T-branch were simulated at Reynolds numbers of 250 and 500, using the software package FIDAP 7.61 to implement the finite element method. The simulations demonstrated that wall Peclet numbers greater than 1.0 were needed to achieve species concentration gradients within the wall that varied in the axial direction, thereby reflecting the influence of disturbed flow and pressure patterns in the lumen. As expected, the transmural concentration gradients were steeper when convection predominated. Blood flow in the lumen can influence the distribution of macromolecules in the arterial wall and needs to be investigated for the relevance to atherosclerosis.

  6. Wall shear stress estimates in coronary artery constrictions

    Science.gov (United States)

    Back, L. H.; Crawford, D. W.

    1992-01-01

    Wall shear stress estimates from laminar boundary layer theory were found to agree fairly well with the magnitude of shear stress levels along coronary artery constrictions obtained from solutions of the Navier Stokes equations for both steady and pulsatile flow. The relatively simple method can be used for in vivo estimates of wall shear stress in constrictions by using a vessel shape function determined from a coronary angiogram, along with a knowledge of the flow rate.

  7. Wall Shear Stress Distribution in Patient Specific Coronary Artery Bifurcation

    Directory of Open Access Journals (Sweden)

    Vahab Dehlaghi

    2010-01-01

    Full Text Available Problem statement: Atherogenesis is affected by hemodynamic parameters, such as wall shear stress and wall shear stress spatial gradient. These parameters are largely dependent on the geometry of arterial tree. Arterial bifurcations contain significant flow disturbances. Approach: The effects of branch angle and vessel diameter ratio at the bifurcations on the wall shear stress distribution in the coronary arterial tree based on CT images were studied. CT images were digitally processed to extract geometrical contours representing the coronary vessel walls. The lumen of the coronary arteries of the patients was segmented using the open source software package (VMTK. The resulting lumens of coronary arteries were fed into a commercial mesh generator (GAMBIT, Fluent Inc. to generate a volume that was filled with tetrahedral elements. The FIDAP software (Fluent Corp. was used to carry out the simulation by solving Navier-Stokes equations. The FIELDVIEW software (Version 10.0, Intelligent Light, Lyndhurst, NJ was used for the visualization of flow patterns and the quantification of wall shear stress. Post processing was done with VMTK and MATLAB. A parabolic velocity profile was prescribed at the inlets and outlets, except for 1. Stress free outlet was assigned to the remaining outlet. Results: The results show that for angle lower than 90°, low shear stress regions are observed at the non-flow divider and the apex. For angle larger than 90°, low shear stress regions only at the non-flow divider. By increasing of diameter of side branch ratio, low shear stress regions in the side branch appear at the non-flow divider. Conclusion: It is concluded that not only angle and diameter are important, but also the overall 3D shape of the artery. More research is required to further quantify the effects angle and diameter on shear stress patterns in coronaries.

  8. Residual stress distribution in a lamellar model of the arterial wall.

    Science.gov (United States)

    Haghighipour, Nooshin; Tafazzoli-Shadpour, Mohammad; Avolio, Albert

    2010-01-01

    Excessive wall circumferential stress in arteries caused by luminal pressure leads to endothelial damage and clinical consequences. In addition to circumferential stress, arterial wall contains residual stress with compressive and tensile components on intima and adventitia sides. The intimal compressive component compensates part of tensile stress induced by blood pressure, hence reduces severity of endothelial tension. The opening angle caused by radial cut of arterial ring defines residual stress. In this study, finite element modelling is used to evaluate residual stress in a lamellar model of human aorta with differing opening angle and elastic modulus. Results show non-linear residual stress profiles across wall thickness, influenced by structural and mechanical parameters. Elevation of opening angle from 50° to 90° leads to increase of intimal compressive component compensating up to 32.6% of the pressure-induced tensile stress. Results may be applied in study of endothelial injury caused by excessive stress in situations such as aging, hypertension and atherosclerosis.

  9. Surgical management of unruptured posterior carotid artery wall aneurysms.

    Science.gov (United States)

    O'Shaughnessy, Brian A; Getch, Christopher C; Bendok, Bernard R; Batjer, H Hunt

    2003-07-15

    Intracranial aneurysms arising from the posterior wall of the supraclinoid carotid artery are extremely common lesions. The aneurysm dilation typically occurs in immediate proximity to the origin of the posterior communicating artery and, less commonly, the anterior choroidal artery (AChA). Because of the increasingly widespread use of noninvasive neuroimaging methods to evaluate patients believed to harbor cerebral lesions, many of these carotid artery aneurysms are now documented in their unruptured state, prior to occurrence of subarachnoid hemorrhage. Based on these factors, the management of unruptured posterior carotid artery (PCA) wall aneurysms is an important element of any neurosurgical practice. Despite impressive recent advances in endovascular therapy, the placement of microsurgical clips to exclude aneurysms with preservation of all afferent and efferent vasculature remains the most efficacious and durable therapy. To date, an optimal outcome is only achieved when the neurosurgeon is able to combine systematic preoperative neurovascular assessment with meticulous operative technique. In this report, the authors review their surgical approach to PCA wall aneurysms, which is greatly based on the extensive neurovascular experience of the senior author. Focus is placed on their methods of preoperative evaluation and operative technique, with emphasis on neurovascular anatomy and the significance of oculomotor nerve compression. They conclude by discussing surgery-related complications, with a particular focus on intraoperative rupture of aneurysms and their management, and the postoperative ischemic AChA syndrome.

  10. Strain assessment in the carotid artery wall using ultrasound speckle tracking: validation in a sheep model

    Science.gov (United States)

    Larsson, Matilda; Verbrugghe, Peter; Smoljkić, Marija; Verhoeven, Jelle; Heyde, Brecht; Famaey, Nele; Herijgers, Paul; D'hooge, Jan

    2015-02-01

    The aim of this study was to validate carotid artery strain assessment in-vivo using ultrasound speckle tracking. The left carotid artery of five sheep was exposed and sonomicrometry crystals were sutured onto the artery wall to obtain reference strain. Ultrasound imaging was performed at baseline and stress, followed by strain estimation using an in-house speckle tracking algorithm tuned for vascular applications. The correlation between estimated and reference strain was r = 0.95 (p speckle tracking. However, further studies are needed to test the algorithm on human in-vivo data and to investigate its potential to detect subclinical cardiovascular disease and characterize atherosclerotic plaques.

  11. High resolution ultrasound and arterial wall changes in early atherosclerosis

    Science.gov (United States)

    Renton, Sophie Caroline

    Non-invasive vascular testing evolved initially to meet the needs of the surgeon to identify haemodynamically significant lesions. However, with refinement of techniques and the development of high resolution ultrasound, it has become possible to detect early lesions and to measure the thickness of die arterial wall with an accuracy of 0.2mm. Such measurements have epidemiological and prognostic potential. They may allow the study of progression (or regression) of atherosclerotic disease before symptoms develop. The aim of this thesis was to assess the value of arterial wall measurements of intima-media thickness and compliance of the common carotid artery in the prediction of early atherosclerotic disease. Four different anatomical patterns of carotid bulb morphology have been identified, according to the position of the bulb origin in relation to the flow divider. It has been demonstrated that bulb morphology influences the site of early plaque formation. The presence of plaque at the carotid and femoral bifurcations was found to be associated with increased intima-media thickening of the common carotid artery. Histological analysis of common carotid arteries taken at post-mortem showed that this diffuse intima-media thickening is the result of deposition of cholesterol crystals, medial atrophy, fatty and fibrous change, and accumulation of necrotic debris, the features characteristic of plaques, even though discrete plaques rarely occur at this site. Subsequently, a number of clinical studies were undertaken which demonstrated that the intima-media thickness is increased in diabetics, hypopituitary patients and claudicants as compared to controls. It was found that the intima-media thickness of the common carotid artery could be used to predict the presence of bifurcation plaques and macrovascular disease. The work of this thesis has demonstrated that high resolution ultrasound is a powerful technique for die study of the arterial wall and should be tested in

  12. Automated Detection of the Arterial Inner Walls of the Common Carotid Artery Based on Dynamic B-Mode Signals

    Directory of Open Access Journals (Sweden)

    Shing-Hong Liu

    2010-11-01

    Full Text Available In this paper we propose a novel scheme able to automatically detect the intima and adventitia of both near and far walls of the common carotid artery in dynamic B-mode RF (radiofrequency image sequences, with and without plaques. Via this automated system the lumen diameter changes along the heart cycle can be detected. Three image sequences have been tested and all results are compared to manual tracings made by two professional experts. The average errors for near and far wall detection are 0.058 mm and 0.067 mm, respectively. This system is able to analyze arterial plaques dynamically which is impossible to do manually due to the tremendous human workload involved.

  13. Wall tissue remodeling regulates longitudinal tension in arteries.

    Science.gov (United States)

    Jackson, Zane S; Gotlieb, Avrum I; Langille, B Lowell

    2002-05-03

    Changes in blood pressure or flow induce arterial remodeling that normalizes mechanical loads that are imposed on arterial tissue. Arteries are also under substantial longitudinal stretch (axial strain) that may be altered by growth or atrophy of tissues to which they are attached. We therefore tested whether axial strain is also regulated in a negative feedback manner through arterial remodeling. Axial strain in rabbit carotid arteries was increased from 62+/-2% to 97+/-2% without altering other mechanical loads on wall tissues. Strain was reduced within 3 days and completely normalized by 7 days. Remodeling involved tissue elaboration, endothelial cell replication rates were increased by >50-fold and smooth muscle cell replication rates were increased by >15-fold, and substantially elevated DNA, elastin, and collagen contents were recorded. Also, increased rates of apoptosis were indicated by degradation of DNA into oligonucleosomes, and matrix remodeling was reflected in enlarged fenestrae in the internal elastic lamina and increased expression and activation of gelatinases, especially matrix metalloproteinase-2. Intriguingly, reduced axial strain was not normalized, presumably because remodeling processes, apart from cell contraction, are ineffective in decreasing strain, and arterial smooth muscle orientation precludes large effects of contraction on axial strain.

  14. Constitutive modelling of an arterial wall supported by microscopic measurements

    Directory of Open Access Journals (Sweden)

    Vychytil J.

    2012-06-01

    Full Text Available An idealized model of an arterial wall is proposed as a two-layer system. Distinct mechanical response of each layer is taken into account considering two types of strain energy functions in the hyperelasticity framework. The outer layer, considered as a fibre-reinforced composite, is modelled using the structural model of Holzapfel. The inner layer, on the other hand, is represented by a two-scale model mimicing smooth muscle tissue. For this model, material parameters such as shape, volume fraction and orientation of smooth muscle cells are determined using the microscopic measurements. The resulting model of an arterial ring is stretched axially and loaded with inner pressure to simulate the mechanical response of a porcine arterial segment during inflation and axial stretching. Good agreement of the model prediction with experimental data is promising for further progress.

  15. Wall morphology, blood flow and wall shear stress: MR findings in patients with peripheral artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Galizia, Mauricio S.; Barker, Alex; Collins, Jeremy; Carr, James [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Liao, Yihua [Northwestern University' s Feinberg School of Medicine, Department of Preventive Medicine, Chicago, IL (United States); McDermott, Mary M. [Northwestern University' s Feinberg School of Medicine, Department of Preventive Medicine, Chicago, IL (United States); Northwestern University' s Feinberg School of Medicine, Department of Medicine, Chicago, IL (United States); Markl, Michael [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Northwestern University, Department Biomedical Engineering, McCormick School of Engineering, Chicago, IL (United States)

    2014-04-15

    To investigate the influence of atherosclerotic plaques on femoral haemodynamics assessed by two-dimensional (2D) phase-contrast (PC) magnetic resonance imaging (MRI) with three-directional velocity encoding. During 1 year, patients with peripheral artery disease and an ankle brachial index <1.00 were enrolled. After institutional review board approval and written informed consent, 44 patients (age, 70 ± 12 years) underwent common femoral artery MRI. Patients with contra-indications for MRI were excluded. Sequences included 2D time-of-flight, proton-density, T1-weighted and T2-weighted MRI. Electrocardiogram (ECG)-gated 2D PC-MRI with 3D velocity encoding was acquired. A radiologist classified images in five categories. Blood flow, velocity and wall shear stress (WSS) along the vessel circumference were quantified from the PC-MRI data. The acquired images were of good quality for interpretation. There were no image quality problems related to poor ECG-gating or slice positioning. Velocities, oscillatory shear stress and total flow were similar between patients with normal arteries and wall thickening/plaque. Patients with plaques demonstrated regionally increased peak systolic WSS and enhanced WSS eccentricity. Combined multi-contrast morphological imaging of the peripheral arterial wall with PC-MRI with three-directional velocity encoding is a feasible technique. Further study is needed to determine whether flow is an appropriate marker for altered endothelial cell function, vascular remodelling and plaque progression. (orig.)

  16. Effects of wall condition on flow distributions in arterial modeling: comparison of rigid, dynamic, and compliant walls

    Energy Technology Data Exchange (ETDEWEB)

    He, Fan [Beijing University of Civil Engineering and Architecture, Beijing (China); Hua, Lu; Gao, Li jian [Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China)

    2016-03-15

    Blood flow distributions were evaluated using various computational strategies. Three commonly used wall conditions in arterial modeling were employed, namely rigid, dynamic and compliant walls. The results show that the velocity distributions are similar under rigid and dynamic walls, developing into the Poiseuille flow, but they are blunt under compliant walls. The peak pressure under rigid walls is highest, but the model of dynamic walls has a good approximation of pressure against the model of compliant walls. The results indicate that a model of compliant walls appears to be a computationally and reasonably accurate approximation of blood velocity distributions compared with the analysis under rigid or dynamic walls. Introducing fluid-structure interaction into arterial modeling is necessary to ensure reliable results and information. However, a model of dynamic walls seems to be a computationally inexpensive yet reasonably accurate approximation for pressure.

  17. Relation between wall shear stress and carotid artery wall thickening MRI versus CFD

    DEFF Research Database (Denmark)

    Cibis, Merih; Potters, Wouter V.; Selwaness, Mariana

    2016-01-01

    Wall shear stress (WSS), a parameter associated with endothelial function, is calculated by computational fluid dynamics (CFD) or phase-contrast (PC) MRI measurements. Although CFD is common in WSS (WSSCFD) calculations, PC-MRI-based WSS (WSSMRI) is more favorable in population studies; since...... it is straightforward and less time consuming. However, it is not clear if WSSMRI and WSSCFD show similar associations with vascular pathology. Our aim was to test the associations between wall thickness (WT) of the carotid arteries and WSSMRI and WSSCFD. The subjects (n=14) with an asymptomatic carotid plaque who...

  18. Computational modeling of hypertensive growth in the human carotid artery

    Science.gov (United States)

    Sáez, Pablo; Peña, Estefania; Martínez, Miguel Angel; Kuhl, Ellen

    2014-06-01

    Arterial hypertension is a chronic medical condition associated with an elevated blood pressure. Chronic arterial hypertension initiates a series of events, which are known to collectively initiate arterial wall thickening. However, the correlation between macrostructural mechanical loading, microstructural cellular changes, and macrostructural adaptation remains unclear. Here, we present a microstructurally motivated computational model for chronic arterial hypertension through smooth muscle cell growth. To model growth, we adopt a classical concept based on the multiplicative decomposition of the deformation gradient into an elastic part and a growth part. Motivated by clinical observations, we assume that the driving force for growth is the stretch sensed by the smooth muscle cells. We embed our model into a finite element framework, where growth is stored locally as an internal variable. First, to demonstrate the features of our model, we investigate the effects of hypertensive growth in a real human carotid artery. Our results agree nicely with experimental data reported in the literature both qualitatively and quantitatively.

  19. Linear and nonlinear viscoelastic arterial wall models: application on animals

    CERN Document Server

    Ghigo, Arthur; Armentano, Ricardo; Lagrée, Pierre-Yves; Fullana, Jose-Maria

    2016-01-01

    This work deals with the viscoelasticity of the arterial wall and its influence on the pulse waves. We describe the viscoelasticity by a non-linear Kelvin-Voigt model in which the coefficients are fitted using experimental time series of pressure and radius measured on a sheep's arterial network. We obtained a good agreement between the results of the nonlinear Kelvin-Voigt model and the experimental measurements. We found that the viscoelastic relaxation time-defined by the ratio between the viscoelastic coefficient and the Young's modulus-is nearly constant throughout the network. Therefore, as it is well known that smaller arteries are stiffer, the viscoelastic coefficient rises when approaching the peripheral sites to compensate the rise of the Young's modulus, resulting in a higher damping effect. We incorporated the fitted viscoelastic coefficients in a nonlinear 1D fluid model to compute the pulse waves in the network. The damping effect of viscoelasticity on the high frequency waves is clear especiall...

  20. Increased wall tension in response to vasoconstrictors in isolated mesenteric arterial rings from patients with high blood pressure.

    Science.gov (United States)

    Tahvanainen, Anna; Taurio, Jyrki; Mäki-Jouppi, Jenni; Kööbi, Peeter; Mustonen, Jukka; Kähönen, Mika; Sand, Juhani; Nordback, Isto; Pörsti, Ilkka

    2006-12-01

    Essential hypertension is associated with several alterations in arterial function. A wealth of information from animal models is available concerning hypertensive changes in the mesenteric circulation, while only few studies have examined human mesenteric arterial function. The tone of isolated mesenteric arterial segments (outer diameter 0.7-0.9 mm) was examined from individuals with high (n=17) or normal (n=22) blood pressure, grouped using the current definition of elevated blood pressure (140/90 mmHg). Since the majority of them were operated because of malignancies, we evaluated whether functional vascular properties provided information about patient prognosis. Wall tension development (mN/mm) in response to vasoconstrictors (noradrenaline, 5-hydroxy tryptamine, potassium chloride) was higher in mesenteric arterial rings from patients with high than normal blood pressure. There was no difference in vasoconstrictor sensitivity, or endothelium-dependent and endothelium-independent vasorelaxation. Arterial segment weight was higher in hypertensive subjects, suggesting vascular wall hypertrophy. The 10-year follow-up showed no differences in the control of arterial tone between the surviving (n=14) or deceased (n=25) patients. In conclusion, isolated mesenteric arterial segments from hypertensive patients showed increased wall tension in response to vasoconstrictors. Since the mesenteric circulation is an important regulator of peripheral arterial resistance, possible functional alterations in this vascular bed should be further investigated in hypertensive patients.

  1. Ultrasound settings significantly alter arterial lumen and wall thickness measurements

    Directory of Open Access Journals (Sweden)

    Green Daniel J

    2008-01-01

    Full Text Available Abstract Background Flow-mediated dilation (FMD and carotid intima-medial thickness (CIMT, measured by ultrasound, are widely used to test the efficacy of cardioprotective interventions. Although assessment methods vary, automated edge-detecting image analysis software is routinely used to measure changes in FMD and CIMT. We aimed to quantify the effect that commonly adjusted ultrasound settings have on arterial lumen and wall thickness measurements made with CIMT measurement software. Methods We constructed phantom arteries from a tissue-mimicking agar compound and scanned them in a water bath with a 10 MHz multi-frequency linear-array probe attached to a high-resolution ultrasound machine. B-mode images of the phantoms were recorded with dynamic range (DR and gain set at five decibel (dB increments from 40 dB to 60 dB and -10 dB to +10 dB respectively. Lumen diameter and wall-thickness were measured off-line using CIMT measurement software. Results Lumen measurements: there was a strong linear relationship between DR and gain and measured lumen diameter. For a given gain level, a 5 dB increase in DR reduced the measured lumen diameter by 0.02 ± 0.004 mm (p CIMT measurements: For a fixed gain level, a 5 dB increase in DR increased measured wall thickness by 0.003 ± 0.002 mm (p Conclusion DR, gain and probe distance significantly alter lumen diameter and CIMT measurements made using image analysis software. When CIMT and FMD are used to test the efficacy of cardioprotective interventions, the DR, gain and probe position used to record baseline scans should be documented and replicated in post-treatment scans in individual trial subjects. If more than one sonographer or imaging centre is used to collect data, the study protocol should document specific DR and gain settings to be used in all subjects.

  2. Arterial wall perfusion measured with photon counting spectral x-ray CT

    Science.gov (United States)

    Jorgensen, Steven M.; Korinek, Mark J.; Vercnocke, Andrew J.; Anderson, Jill L.; Halaweish, Ahmed; Leng, Shuai; McCollough, Cynthia H.; Ritman, Erik L.

    2016-10-01

    Early atherosclerosis changes perfusion of the arterial wall due to localized proliferation of the vasa vasorum. When contrast agent passes through the artery, some enters the vasa vasorum and increases radiopacity of the arterial wall. Technical challenges to detecting changes in vasa vasorum density include the thin arterial wall, partial volume averaging at the arterial lumen/wall interface and calcification within the wall. We used a photon-counting spectral CT scanner to study carotid arteries of anesthetized pigs and micro-CT of these arteries to quantify vasa vasorum density. The left carotid artery wall was injected with autologous blood to stimulate vasa vasorum angiogenesis. The scans were performed at 25-120 keV; the tube-current-time product was 550 mAs. A 60 mL bolus of iodine contrast agent was injected into the femoral vein at 5mL/s. Two seconds post injection, an axial scan was acquired at every 3 s over 60 s (i.e., 20 time points). Each time point acquired 28 contiguous transaxial slices with reconstructed voxels 0.16 x 0.16 x 1 mm3. Regions-of-interest in the outer 2/3 of the arterial wall and in the middle 2/3 of the lumen were drawn and their enhancements plotted versus time. Lumenal CT values peaked several seconds after injection and then returned towards baseline. Arterial wall CT values peaked concurrent to the lumen. The peak arterial wall enhancement in the left carotid arterial wall correlated with increased vasa vasorum density observed in micro-CT images of the isolated arteries.

  3. The effect of arterial wall shear stress on the incremental elasticity of a conduit artery.

    Science.gov (United States)

    Kelly, R F; Snow, H M

    2011-05-01

    The purpose of this investigation was to determine the effects of flow mediated dilatation on arterial incremental elasticity (E(inc) ).   In four female anaesthetized pigs, the iliac artery and vein were connected by a shunt with a variable resistance which allowed blood flow and therefore shear stress to be regulated. E(inc) was calculated from simultaneous records of diameter and pressure throughout a minimum of four cardiac cycles. Passive increases in diameter (∼1-2%) throughout a cardiac cycle, brought about by pressure, resulted in a two- to threefold increase in E(inc) . In contrast, increases in shear stress caused active smooth muscle relaxation and a significant increase in diameter from 3.663 ± 0.215 mm to 4.488 ± 0.163 mm (mean ± SEM, P stress, the interaction between smooth muscle and collagen operates so as to maintain E(inc) relatively constant over much of the working range of dilatation. This is consistent with a model of the arterial wall in which collagen is recruited both by passive stretch, in response to an increase in pressure and therefore wall stress, and also by active contraction of smooth muscle. © 2011 The Authors. Acta Physiologica © 2011 Scandinavian Physiological Society.

  4. Relaxed incremental variational approach for the modeling of damage-induced stress hysteresis in arterial walls.

    Science.gov (United States)

    Schmidt, Thomas; Balzani, Daniel

    2016-05-01

    In this paper, a three-dimensional relaxed incremental variational damage model is proposed, which enables the description of complex softening hysteresis as observed in supra-physiologically loaded arterial tissues, and which thereby avoids a loss of convexity of the underlying formulation. The proposed model extends the relaxed formulation of Balzani and Ortiz [2012. Relaxed incremental variational formulation for damage at large strains with application to fiber-reinforced materials and materials with truss-like microstructures. Int. J. Numer. Methods Eng. 92, 551-570], such that the typical stress-hysteresis observed in arterial tissues under cyclic loading can be described. This is mainly achieved by constructing a modified one-dimensional model accounting for cyclic loading in the individual fiber direction and numerically homogenizing the response taking into account a fiber orientation distribution function. A new solution strategy for the identification of the convexified stress potential is proposed based on an evolutionary algorithm which leads to an improved robustness compared to solely Newton-based optimization schemes. In order to enable an efficient adjustment of the new model to experimentally observed softening hysteresis, an adjustment scheme using a surrogate model is proposed. Therewith, the relaxed formulation is adjusted to experimental data in the supra-physiological domain of the media and adventitia of a human carotid artery. The performance of the model is then demonstrated in a finite element example of an overstretched artery. Although here three-dimensional thick-walled atherosclerotic arteries are considered, it is emphasized that the formulation can also directly be applied to thin-walled simulations of arteries using shell elements or other fiber-reinforced biomembranes.

  5. Calculation of arterial wall temperature in atherosclerotic arteries: effect of pulsatile flow, arterial geometry, and plaque structure

    Directory of Open Access Journals (Sweden)

    Kim Taehong

    2007-03-01

    Full Text Available Abstract Background This paper presents calculations of the temperature distribution in an atherosclerotic plaque experiencing an inflammatory process; it analyzes the presence of hot spots in the plaque region and their relationship to blood flow, arterial geometry, and inflammatory cell distribution. Determination of the plaque temperature has become an important topic because plaques showing a temperature inhomogeneity have a higher likelihood of rupture. As a result, monitoring plaque temperature and knowing the factors affecting it can help in the prevention of sudden rupture. Methods The transient temperature profile in inflamed atherosclerotic plaques is calculated by solving an energy equation and the Navier-Stokes equations in 2D idealized arterial models of a bending artery and an arterial bifurcation. For obtaining the numerical solution, the commercial package COMSOL 3.2 was used. The calculations correspond to a parametric study where arterial type and size, as well as plaque geometry and composition, are varied. These calculations are used to analyze the contribution of different factors affecting arterial wall temperature measurements. The main factors considered are the metabolic heat production of inflammatory cells, atherosclerotic plaque length lp, inflammatory cell layer length lmp, and inflammatory cell layer thickness dmp. Results The calculations indicate that the best location to perform the temperature measurement is at the back region of the plaque (0.5 ≤ l/lp ≤ 0.7. The location of the maximum temperature, or hot spot, at the plaque surface can move during the cardiac cycle depending on the arterial geometry and is a direct result of the blood flow pattern. For the bending artery, the hot spot moves 0.6 millimeters along the longitudinal direction; for the arterial bifurcation, the hot spot is concentrated at a single location due to the flow recirculation observed at both ends of the plaque. Focusing on the

  6. Effect of Hematocrit on Wall Shear Stress for Blood Flow through Tapered Artery

    OpenAIRE

    Singh, A. K.; Singh, D. P.

    2013-01-01

    The purpose of this study to show the effects of Hematocrit (Red blood cells), height of stenosis, porous parameter and velocity of blood on wall shear stress of the flow of blood through tapered artery. The study reveals that wall shear stress reduces for increasing Hematocrit percentage. It is also observed that wall shear stress increases as stenosis height and porous parameter increase whereas it decreases with the increasing values of velocity of blood and slope of tapered artery.

  7. A Laser-Assisted Anastomotic Technique : Feasibility on Human Diseased Coronary Arteries

    NARCIS (Netherlands)

    Stecher, David; Bronkers, Glenn; Vink, Aryan; Homoet-van der Kraak, Petra H|info:eu-repo/dai/nl/313984166; Helthuis, Jasper; Pasterkamp, Gerard|info:eu-repo/dai/nl/138488304; Buijsrogge, Marc P|info:eu-repo/dai/nl/24420098X

    2016-01-01

    OBJECTIVE: Atherosclerotic disease might hamper the efficacy of the Excimer laser-assisted Trinity Clip anastomotic connector in coronary arteries. Therefore, its efficacy was evaluated on human diseased coronary arteries (study 1). In addition, the acute laser effects onto the coronary wall were as

  8. Exercise and arterial adaptation in humans: uncoupling localized and systemic effects

    NARCIS (Netherlands)

    Rowley, N.J.; Dawson, E.A.; Birk, G.K.; Cable, N.T.; George, K.; Whyte, G.; Thijssen, D.H.J.; Green, D.J.

    2011-01-01

    Previous studies have established effects of exercise training on arterial wall thickness, remodeling, and function in humans, but the extent to which these changes are locally or systemically mediated is unclear. We examined the brachial arteries of the dominant (D) and nondominant (ND) upper limbs

  9. Microstructure and mechanics of human resistance arteries.

    Science.gov (United States)

    Bell, J S; Adio, A O; Pitt, A; Hayman, L; Thorn, C E; Shore, A C; Whatmore, J L; Winlove, C P

    2016-12-01

    Vascular diseases such as diabetes and hypertension cause changes to the vasculature that can lead to vessel stiffening and the loss of vasoactivity. The microstructural bases of these changes are not presently fully understood. We present a new methodology for stain-free visualization, at a microscopic scale, of the morphology of the main passive components of the walls of unfixed resistance arteries and their response to changes in transmural pressure. Human resistance arteries were dissected from subcutaneous fat biopsies, mounted on a perfusion myograph, and imaged at varying transmural pressures using a multimodal nonlinear microscope. High-resolution three-dimensional images of elastic fibers, collagen, and cell nuclei were constructed. The honeycomb structure of the elastic fibers comprising the internal elastic layer became visible at a transmural pressure of 30 mmHg. The adventitia, comprising wavy collagen fibers punctuated by straight elastic fibers, thinned under pressure as the collagen network straightened and pulled taut. Quantitative measurements of fiber orientation were made as a function of pressure. A multilayer analytical model was used to calculate the stiffness and stress in each layer. The adventitia was calculated to be up to 10 times as stiff as the media and experienced up to 8 times the stress, depending on lumen diameter. This work reveals that pressure-induced reorganization of fibrous proteins gives rise to very high local strain fields and highlights the unique mechanical roles of both fibrous networks. It thereby provides a basis for understanding the micromechanical significance of structural changes that occur with age and disease.

  10. Thermomechanical behavior of human carotid arteries in the passive state.

    Science.gov (United States)

    Guinea, G V; Atienza, J M; Elices, M; Aragoncillo, P; Hayashi, K

    2005-06-01

    Localized heating or cooling is expanding the clinical procedures used to treat cardiovascular diseases. Advantageous implementation and development of these methods are linked indissolubly to a deeper understanding of the arterial response to combined mechanical and thermal loads. Despite this, the basic thermomechanical behavior of human blood vessels still remains largely unknown, primarily due to the lack of appropriate experimental data. In this work, the influence of temperature on the passive behavior of human carotid arteries was studied in vitro by means of inflation tests. Eleven carotid segments were tested in the range 0-200 mmHg at four different temperatures of 17, 27, 37, and 42 degrees C. The results show that the combined change of temperature and stress has a dramatic effect on the dilatation coefficient of the arterial wall, which is shifted from negative to positive depending on the stress state, whereas the structural stiffness of the arterial wall does not change appreciably in the range of temperatures tested.

  11. Simulation of Contrast Agent Transport in Arteries with Multilayer Arterial Wall: Impact of Arterial Transmural Transport on the Bolus Delay and Dispersion

    Directory of Open Access Journals (Sweden)

    Min Xu

    2014-01-01

    Full Text Available One assumption of DSC-MRI is that the injected contrast agent is kept totally intravascular and the arterial wall is impermeable to contrast agent. The assumption is unreal for such small contrast agent as Gd-DTPA can leak into the arterial wall. To investigate whether the unreal assumption is valid for the estimation of the delay and dispersion of the contrast agent bolus, we simulated flow and Gd-DTPA transport in a model with multilayer arterial wall and analyzed the bolus delay and dispersion qualified by mean vascular transit time (MVTT and the variance of the vascular transport function. Factors that may affect Gd-DTPA transport hence the delay and dispersion were further investigated, such as integrity of endothelium and disturbed flow. The results revealed that arterial transmural transport would slightly affect MVTT and moderately increase the variance. In addition, although the integrity of endothelium can significantly affect the accumulation of contrast agent in the arterial wall, it had small effects on the bolus delay and dispersion. However, the disturbed flow would significantly increase both MVTT and the variance. In conclusion, arterial transmural transport may have a small effect on the bolus delay and dispersion when compared to the flow pattern in the artery.

  12. Modelling non-symmetric collagen fibre dispersion in arterial walls.

    Science.gov (United States)

    Holzapfel, Gerhard A; Niestrawska, Justyna A; Ogden, Ray W; Reinisch, Andreas J; Schriefl, Andreas J

    2015-05-06

    New experimental results on collagen fibre dispersion in human arterial layers have shown that the dispersion in the tangential plane is more significant than that out of plane. A rotationally symmetric dispersion model is not able to capture this distinction. For this reason, we introduce a new non-symmetric dispersion model, based on the bivariate von Mises distribution, which is used to construct a new structure tensor. The latter is incorporated in a strain-energy function that accommodates both the mechanical and structural features of the material, extending our rotationally symmetric dispersion model (Gasser et al. 2006 J. R. Soc. Interface 3, 15-35. (doi:10.1098/rsif.2005.0073)). We provide specific ranges for the dispersion parameters and show how previous models can be deduced as special cases. We also provide explicit expressions for the stress and elasticity tensors in the Lagrangian description that are needed for a finite-element implementation. Material and structural parameters were obtained by fitting predictions of the model to experimental data obtained from human abdominal aortic adventitia. In a finite-element example, we analyse the influence of the fibre dispersion on the homogeneous biaxial mechanical response of aortic strips, and in a final example the non-homogeneous stress distribution is obtained for circumferential and axial strips under fixed extension. It has recently become apparent that this more general model is needed for describing the mechanical behaviour of a variety of fibrous tissues.

  13. In vitro model of atherosclerosis using coculture of arterial wall cells and macrophage.

    Science.gov (United States)

    Wada, Y; Sugiyama, A; Kohro, T; Kobayashi, M; Takeya, M; Naito, M; Kodama, T

    2000-12-01

    In order to determine the precise mechanism of the interactions between different types of cells, which are common phenomena in tissues and organs, the importance of coculture techniques are becoming increasingly important. In the area of cardiology, artificial arteries have been developed, based on the understanding of physiological communication of the arterial smooth muscle cells (SMC), endothelial cells (EC), and the extracellular matrix (ECM). In the study of atherosclerosis, the modification of low-density lipoprotein (LDL), which result in the recruitment and accumulation of white blood cells, especially, monocytes/macrophages, and foam cell formation, are hypothesized. Although there are well known animal models, an in vitro model of atherogenesis with a precisely known atherogenesis mechanism has not yet been developed. In this paper, an arterial wall reconstruction model using rabbit primary cultivated aortic SMCs and ECs, was shown. In addition, human peripheral monocytes were used and the transmigration of monocytes was observed by scanning electron and laser confocal microscopy. Monocyte differentiation into macrophages was shown by immunohistochemistry and comprehensive gene expression analysis. With the modified form of LDL, the macrophages were observed to accumulate lipids with a foamy appearance and differentiate into the foam cells in the ECM between the ECs and SMCs in the area of our coculture model.

  14. Arterial embolization for traumatic lethal lateral abdomi-nal wall hemorrhage in a liver cirrhosis patient

    Institute of Scientific and Technical Information of China (English)

    Seiji Morita; Tomoatsu Tsuji; Takeshi Yamagiwa; Hiroyuki Otsuka; Sadaki Inokuchi

    2009-01-01

    @@ B lood loss due to abdominal wall hemorrhage is generally managed conservatively. Further, abdominal wall hemorrhage rarely develops into a life-threatening condition. However, it is difficult to sur-gically achieve hemostasis. We report the case of a liver cirrhosis patient with life-threatening abdominal wall hemorrhage that developed as a result of a minor trauma and was successfully treated with arterial embolization (AE).

  15. Adult Vascular Wall Resident Multipotent Vascular Stem Cells, Matrix Metalloproteinases, and Arterial Aneurysms

    Directory of Open Access Journals (Sweden)

    Bruno Amato

    2015-01-01

    Full Text Available Evidences have shown the presence of multipotent stem cells (SCs at sites of arterial aneurysms: they can differentiate into smooth muscle cells (SMCs and are activated after residing in a quiescent state in the vascular wall. Recent studies have implicated the role of matrix metalloproteinases in the pathogenesis of arterial aneurysms: in fact the increased synthesis of MMPs by arterial SMCs is thought to be a pivotal mechanism in aneurysm formation. The factors and signaling pathways involved in regulating wall resident SC recruitment, survival, proliferation, growth factor production, and differentiation may be also related to selective expression of different MMPs. This review explores the relationship between adult vascular wall resident multipotent vascular SCs, MMPs, and arterial aneurysms.

  16. Effects of the three-dimensional residual stresses on the mechanical properties of arterial walls.

    Science.gov (United States)

    Zheng, Xianbing; Ren, Jiusheng

    2016-03-21

    Effects of the three-dimensional residual stresses on the mechanical properties of arterial walls are analyzed in this paper, based on the model which considered the bending and stretching both in the circumferential and axial directions of the three distinct arterial layers. Moreover, different constitutive models are proposed to quantify the nonlinear mechanics of the three distinct layers and the important constituents, i.e. elastin, collagen fibers and smooth muscle cells (SMCs), are all taken into account. The stress distributions and pressure-radius curves of the arterial wall are given in details. Results demonstrate that the maximum values of the circumferential stress and the corresponding stress gradient in the media under the mean arterial pressure are reduced significantly as a consequence of the SMCs. The bending in the axial direction of the media and the opening angle of the intima have an obvious impact on the mechanical behaviors of arterial walls. This study may not only develop the understanding of effects of the three-dimensional residual stresses on the arterial wall response, but also can increase the accuracy of the analyses for patient-specific studies used for the treatments of arterial diseases. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Wall Shear Stress Prediction Using Computational Simulation on Patient Specific Artery with Aneurysm

    Directory of Open Access Journals (Sweden)

    Yunus Muhamad

    2014-07-01

    Full Text Available An aneurysm is formed when a blood vessel becomes dilated or distorted. It will cause the vessel to expand to a size greater than its original diameter. In this study, Wall Shear Stress (WSS of cerebral artery with aneurysm was predicted using Computational Fluid Dynamics (CFD. WSS in the artery is one of the indicators for brain artery disease progression. Based on the results, the maximum value of blood velocity and WSS on patient specific artery with aneurysm are 3.23 m/s and 60.1 Pa, respectively. The location of high WSS is before and after the aneurysm bulge. The WSS is above the normal physiological value where the artery wall is exposed to high stress. Hence, the vessel at this location is anticipated to become weaker and could be further dilated.

  18. A finite element study of balloon expandable stent for plaque and arterial wall vulnerability assessment

    Science.gov (United States)

    Karimi, Alireza; Navidbakhsh, Mahdi; Razaghi, Reza

    2014-07-01

    The stresses induced within plaque tissues and arterial layers during stent expansion inside an atherosclerotic artery can be exceeded from the yield stresses of those tissues and, consequently, lead to plaque or arterial layer rupture. The distribution and magnitude of the stresses in each component involved in stenting might be clearly different for different plaque types and different arterial layers. In this study, a nonlinear finite element simulation was employed to investigate the effect of plaque composition (calcified, cellular, and hypocellular) on the stresses induced in the arterial layers (intima, media, and adventitia) during implantation of a balloon expandable coronary stent into a stenosed artery. The atherosclerotic artery was assumed to consist of a plaque and normal/healthy arterial tissues on its outer side. The results indicated a significant influence of plaque types on the maximum stresses induced within the plaque wall and arterial layers during stenting but not when computing maximum stress on the stent. The stress on the stiffest calcified plaque wall was in the fracture level (2.38 MPa), whereas cellular and hypocellular plaques remain stable owing to less stress on their walls. Regardless of plaque types, the highest von Mises stresses were observed on the stiffest intima layer, whereas the lowest stresses were seen to be located in less stiff media layer. The computed stresses on the intima layer were found to be high enough to initiate a rupture in this stiff layer. These findings suggest a higher risk of arterial vascular injury for the intima layer, while a lower risk of arterial injury for the media and adventitia layers.

  19. Lateral abdominal wall hematoma as a rare complication after carotid artery stenting: a case report

    Directory of Open Access Journals (Sweden)

    Satomi Jyunichiro

    2009-11-01

    Full Text Available Abstract Abdominal wall hematoma is a rare and life-threatening complication after carotid artery stenting (CAS, but it can occur when activated clotting time is prolonged. We report a right lateral abdominal wall hematoma caused by rupture of the superficial circumflex iliac artery after CAS in a 72-year-old man with severe stenosis of the origin of the right internal carotid artery. We performed CAS for the targeted lesion while activated clotting time exceeded 300 seconds. After 2 hours, he complained of right lateral abdominal pain. Abdominal computed tomography revealed an extensive hematoma in the right lateral abdominal wall. Activated clotting time was 180 seconds at this point. Seven hours later, he developed hypotension and hemoglobin level dropped to 11.3 g/dl. Subsequent computed tomography showed enlargement of the hematoma. Emergent selective angiography of the external iliac artery revealed active bleeding from the right superficial circumflex iliac artery. Transcatheter arterial embolization with Gelfoam and microcoils was performed successfully. With more CAS procedures being performed, it is important for endovascular surgeons and radiologists to consider the possibility of abdominal wall hematoma in this situation.

  20. Determination of wall tension in cerebral artery aneurysms by numerical simulation

    DEFF Research Database (Denmark)

    Isaksen, J.G.; Bazilevs, Y.; Kvamsdal, T.

    2008-01-01

    BACKGROUND AND PURPOSE: Cerebral artery aneurysms rupture when wall tension exceeds the strength of the wall tissue. At present, risk-assessment of unruptured aneurysms does not include evaluation of the lesions shape, yet clinical experience suggests that this is of importance. We aimed to develop...... a computational model for simulation of fluid-structure interaction in cerebral aneurysms based on patient specific lesion geometry, with special emphasis on wall tension. METHODS: An advanced isogeometric fluid-structure analysis model incorporating flexible aneurysm wall based on patient specific computed...... tomography angiogram images was developed. Variables used in the simulation model were retrieved from a literature review. RESULTS: The simulation results exposed areas of high wall tension and wall displacement located where aneurysms usually rupture. CONCLUSIONS: We suggest that analyzing wall tension...

  1. Combination treatment of rosuvastatin or atorvastatin, with regular exercise improves arterial wall stiffness in patients with coronary artery disease.

    Directory of Open Access Journals (Sweden)

    Kensuke Toyama

    Full Text Available OBJECTIVE: Statin- and exercise-therapy are both clinically beneficial by preventing cardiovascular events in patients with coronary artery disease (CAD. However, there is no information on the vascular effects of the combination of statins and exercise on arterial wall stiffness in CAD patients. METHODS: The present study is a sub-analysis of PRESET study that determined the effects of 20-week treatment with statins (rosuvastatin, n=14, atorvastatin, n=14 combined with regular exercise on arterial wall stiffness assessed by measurement of brachial and ankle pulse wave velocity (baPWV in CAD patients. RESULTS: The combination of statins and regular exercise significantly improved exercise capacity, lipid profile, including low- and high-density lipoprotein cholesterol, and high-sensitivity C-reactive protein (hs-CRP, baPWV (baseline: 1747 ± 355, at 20 weeks of treatment: 1627 ± 271 cm/s, p=0.008, and basophil count (baseline: 42 ± 32, 20 weeks: 26 ± 15 cells/µL, p=0.007, but had no effect on blood pressure (baseline: 125 ± 22, 20 weeks: 121 ± 16 mmHg. Changes in baPWV correlated significantly with changes in basophil count (r=0.488, p=0.008, but not with age, lipids profile, exercise capacity, or hs-CRP. CONCLUSION: In CAD patients, the combination treatment with statins and exercise resulted in significant amelioration of arterial wall stiffness, at least in part, through reduction of circulating basophils.

  2. Experience With Intravascular Ultrasound Imaging Of Human Atherosclerotic Arteries

    Science.gov (United States)

    Mallery, John A.; Gessert, James M.; Maciel, Mario; Tobis, John M.; Griffith, James M.; Berns, Michael W.; Henry, Walter L.

    1989-08-01

    Normal human arteries have a well-defined structure on intravascular images. The intima appears very thin and is most likely represented by a bright reflection arising from the internal elastic lamina. The smooth muscle tunica media is echo-lucent on the ultrasound image and appears as a dark band separating the intima from the adventitia. The adventitia is a brightly reflective layer of variable thickness. The thickness of the intima, and therefore of the atherosclerotic plaque can be accurately measured from the ultrasound images and correlates well with histology. Calcification within the wall of arteries is seen as bright echo reflection with shadowing of the peripheral wall. Fibrotic regions are highly reflective but do not shadow. Necrotic liquid regions within advanced atherosclerotic plaques are seen on ultrasound images as large lucent zones surrounded by echogenic tissue. Imaging can be performed before and after interventional procedures, such as laser angioplasty, balloon angioplasty and atherectomy. Intravascular ultrasound appears to provide an imaging modality for identifying the histologic characteristics of diseased arteries and for quantifying plaque thickness. It might be possible to perform such quantification to evaluate the results of interventional procedures.

  3. Artery buckling analysis using a two-layered wall model with collagen dispersion.

    Science.gov (United States)

    Mottahedi, Mohammad; Han, Hai-Chao

    2016-07-01

    Artery buckling has been proposed as a possible cause for artery tortuosity associated with various vascular diseases. Since microstructure of arterial wall changes with aging and diseases, it is essential to establish the relationship between microscopic wall structure and artery buckling behavior. The objective of this study was to developed arterial buckling equations to incorporate the two-layered wall structure with dispersed collagen fiber distribution. Seven porcine carotid arteries were tested for buckling to determine their critical buckling pressures at different axial stretch ratios. The mechanical properties of these intact arteries and their intima-media layer were determined via pressurized inflation test. Collagen alignment was measured from histological sections and modeled by a modified von-Mises distribution. Buckling equations were developed accordingly using microstructure-motivated strain energy function. Our results demonstrated that collagen fibers disperse around two mean orientations symmetrically to the circumferential direction (39.02°±3.04°) in the adventitia layer; while aligning closely in the circumferential direction (2.06°±3.88°) in the media layer. The microstructure based two-layered model with collagen fiber dispersion described the buckling behavior of arteries well with the model predicted critical pressures match well with the experimental measurement. Parametric studies showed that with increasing fiber dispersion parameter, the predicted critical buckling pressure increases. These results validate the microstructure-based model equations for artery buckling and set a base for further studies to predict the stability of arteries due to microstructural changes associated with vascular diseases and aging.

  4. Theoretical study of dynamics of arterial wall remodeling in response to changes in blood pressure.

    Science.gov (United States)

    Rachev, A; Stergiopulos, N; Meister, J J

    1996-05-01

    The dynamics of arterial wall remodeling was studied on the basis of a phenomenological mathematical model. Sustained hypertension was simulated by a step increase in blood pressure. Remodeling rate equations were postulated for the evolution of the geometrical dimensions that characterize the zero stress state of the artery. The driving stimuli are the deviations of the extreme values of the circumferential stretch ratios and the average stress from their values at the normotensive state. Arterial wall was considered to be a thick-walled tube made of nonlinear elastic incompressible material. Results showed that thickness increases montonically with time whereas the opening angle exhibits a biphasic pattern. Geometric characteristics reach asymptotically a new homeostatic steady state, in which the stress and strain distribution is practically identical with the distribution under normotensive conditions. The model predictions are in good agreement with published experimental findings.

  5. Solutions of the Maxwell viscoelastic equations for displacement and stress distributions within the arterial wall.

    Science.gov (United States)

    Hodis, S; Zamir, M

    2008-08-01

    Mechanical events within the thickness of the vessel wall caused by pulsatile blood flow are considered, with focus on axial dynamics of the wall, driven by the oscillatory drag force exerted by the fluid on the endothelial layer of the wall. It is shown that the focus on the axial direction makes it possible to derive simplified equations of motion which, combined with a viscoelastic model of the wall material, makes it possible in turn to obtain solutions in closed form for the displacement and stress of material elements within the wall. The viscoelastic model allows a study of the dynamics of the wall with different ratios of viscosity to elasticity of the wall material, to mimic changes in the properties of the arterial wall caused by disease or aging. It is found that when the wall is highly viscous the displacements and stresses caused by the flow are confined to a thin layer close to the inner boundary of the wall, while as the wall material becomes less viscous and more rigid the displacements and stresses spread deeper into the thickness of the wall to affect most of its elements.

  6. Association between uterine artery Doppler blood flow changes and arterial wall elasticity in pregnant women.

    Science.gov (United States)

    von Wowern, Emma; Andersson, Jakob; Skarping, Ida Dalene; Howie, Maria Teresa; Olofsson, Per

    2017-10-01

    Uterine artery (UtA) Doppler velocimetry changes and increased arterial stiffness are associated with preeclampsia. We aimed to investigate the relation between UtA velocimetry changes and arterial stiffness in pregnant women. Doppler velocimetry and photoplethysmographic digital pulse wave analysis (DPA) were performed in 173 pregnant women in the second or the third trimester, where UtA Doppler pulsatility index (PI), diastolic notching, and UtA score (UAS) combining notching and high PI were calculated. DPA stiffness parameters representing large arteries were ejection elasticity index (EEI) and b/a, small arteries dicrotic index (DI) and d/a, and global stiffness the aging index (AI). One hundred and thirty women had normal Doppler and 43 had diastolic notching, of whom nine had high PI. DI indicated increased stiffness in small arteries when notching was present (p = 0.044) and showed a significant but weak correlation to UAS (p = 0.025, tau 0.12). EEI and b/a indicated increased large artery stiffness (p ≤0.014), d/a small artery stiffness (p = 0.023), and AI a systemic stiffness (p = 0.040) when high PI. High UtA PI was associated with increased systemic arterial stiffness, whereas notching was related to increased stiffness in small arteries only. This indicates pathophysiological differences between the two Doppler parameters.

  7. Simulation of stent deployment in a realistic human coronary artery

    Directory of Open Access Journals (Sweden)

    van der Steen Anton FW

    2008-08-01

    Full Text Available Abstract Background The process of restenosis after a stenting procedure is related to local biomechanical environment. Arterial wall stresses caused by the interaction of the stent with the vascular wall and possibly stress induced stent strut fracture are two important parameters. The knowledge of these parameters after stent deployment in a patient derived 3D reconstruction of a diseased coronary artery might give insights in the understanding of the process of restenosis. Methods 3D reconstruction of a mildly stenosed coronary artery was carried out based on a combination of biplane angiography and intravascular ultrasound. Finite element method computations were performed to simulate the deployment of a stent inside the reconstructed coronary artery model at inflation pressure of 1.0 MPa. Strut thickness of the stent was varied to investigate stresses in the stent and the vessel wall. Results Deformed configurations, pressure-lumen area relationship and stress distribution in the arterial wall and stent struts were studied. The simulations show how the stent pushes the arterial wall towards the outside allowing the expansion of the occluded artery. Higher stresses in the arterial wall are present behind the stent struts and in regions where the arterial wall was thin. Values of 200 MPa for the peak stresses in the stent strut were detected near the connecting parts between the stent struts, and they were only just below the fatigue stress. Decreasing strut thickness might reduce arterial damage without increasing stresses in the struts significantly. Conclusion The method presented in this paper can be used to predict stresses in the stent struts and the vessel wall, and thus evaluate whether a specific stent design is optimal for a specific patient.

  8. N-3 vs. saturated fatty acids: effects on the arterial wall.

    Science.gov (United States)

    Sudheendran, S; Chang, C C; Deckelbaum, R J

    2010-01-01

    Cardiovascular disease is a leading cause of death worldwide. Atherosclerosis and unstable plaques are underlying causes for cardiovascular diseases. Cardiovascular disease is associated with consumption of diets high in saturated fats. In contrast there is increasing evidence that higher intakes of dietary n-3 fatty acids decrease risk for cardiovascular disease. Recent studies are beginning to clarify how n-3 compared with saturated fatty acids influence cardiovascular disease risk via pathways in the arterial wall. In this paper we will review studies that report on mechanisms whereby dietary fatty acids affect atherosclerosis through modulation of arterial wall lipid deposition, inflammation, cell proliferation, and plaque vulnerability.

  9. [Assessment of arterial wall stiffness by 24-hour blood pressure monitoring].

    Science.gov (United States)

    Korneva, V A; Kuznetsova, T Yu

    2016-01-01

    Arterial wall stiffness is an early marker of cardiovascular diseases. The gold standard for assessment of the stiffness of large vessels is presently pulse wave velocity (PWV). Work is in progress on the study of the reference values of PWV in people of different genders and ages. 24-hour blood pressure (BP) monitoring is not only a procedure that can estimate diurnal BP variability, but also monitor the indicators of vascular wall stiffness in a number of cases over a 24-hour period. The given review highlights the pathophysiology of arterial stiffness, methods for its assessment, and the aspects of use in therapeutic practice.

  10. Structural-and-functional alterations in the arterial wall and clinical manifestations of nonspecific aortoarteritis.

    Science.gov (United States)

    Pokrovskiĭ, A V; Kuntsevich, G I; Zotikov, E A; Burtseva, E A; Kulbak, V A

    2009-01-01

    The authors studied structural-and-functional properties of the arterial wall, also assessing elastic properties of the common femoral artery and the brachial artery flow-dependent dilatation (FDD) index in a total of thirty-six patients presenting with nonspecific aortoarteritis (NAA). The overwhelming majority of the patients, i. e., twenty-four (89%), showed a statistically significant decrease in the FDD as compared with the control-group patients (P<0.05). We revealed a statistically reliable (P=0.0005) inverse correlation between the level of systolic arterial pressure and an increase in the rigidity index of the common femoral artery wall. Also determined was a correlation of the femoral artery wall rigidity (systolic AP equalling 140 mm Hg and higher) and the brachial artery flow-dependent dilatation index (r=-0.61). All the patients suffering from non-specific aortoarteritis were diagnosed as having a decrease in the elasticity values, accompanied by an increase in systolic arterial pressure (r=0.36; P=0.07). Comparing the level of systolic arterial pressure with the values of the distensibility coefficient and compliance coefficient revealed a weak inverse correlation (r=-0.28 and 0.21, respectively). Evaluating the impact of duration of the disease on the distensibility coefficient, compliance coefficient and the rigidity index made it possible to detect a statistically significant (P=0.0039) direct correlation between the rigidity index and the duration of non-specific aortoarteritis. To a leaser degree, the duration of the inflammatory process influenced the distensibility coefficient and compliance coefficient (r=-0.28; r=-0.30, respectively; P=0.06).

  11. Fibrillar, fibril-associated and basement membrane collagens of the arterial wall: architecture, elasticity and remodeling under stress.

    Science.gov (United States)

    Osidak, M S; Osidak, E O; Akhmanova, M A; Domogatsky, S P; Domogatskaya, A S

    2015-01-01

    The ability of a human artery to pass through 150 million liters of blood sustaining 2 billion pulsations of blood pressure with minor deterioration depends on unique construction of the arterial wall. Viscoelastic properties of this construction enable to re-seal the occuring damages apparently without direct immediate participance of the constituent cells. Collagen structures are considered to be the elements that determine the mechanoelastic properties of the wall in parallel with elastin responsible for elasticity and resilience. Collagen scaffold architecture is the function-dependent dynamic arrangement of a dozen different collagen types composing three distinct interacting forms inside the extracellular matrix of the wall. Tightly packed molecules of collagen types I, III, V provide high tensile strength along collagen fibrils but toughness of the collagen scaffold as a whole depends on molecular bonds between distinct fibrils. Apart of other macromolecules in the extracellular matrix (ECM), collagen-specific interlinks involve microfilaments of collagen type VI, meshwork-organized collagen type VIII, and FACIT collagen type XIV. Basement membrane collagen types IV, XV, XVIII and cell-associated collagen XIII enable transmission of mechanical signals between cells and whole artery matrix. Collagen scaffold undergoes continuous remodeling by decomposition promoted with MMPs and reconstitution from newly produced collagen molecules. Pulsatile stress-strain load modulates both collagen synthesis and MMP-dependent collagen degradation. In this way the ECM structure becomes adoptive to mechanical challenges. The mechanoelastic properties of the arterial wall are changed in atherosclerosis concomitantly with collagen turnover both type-specific and dependent on the structure. Improving the feedback could be another approach to restore sufficient blood circulation.

  12. Influence of arterial wall-stenosis compliance on the coronary diagnostic parameters.

    Science.gov (United States)

    Konala, Bhaskar Chandra; Das, Ashish; Banerjee, Rupak K

    2011-03-15

    Functional diagnostic parameters such as Fractional Flow Reserve (FFR), which is calculated from pressure measurements across stenosed arteries, are often used to determine the functional severity of coronary artery stenosis. This study evaluated the effect of arterial wall-stenosis compliance, with limiting scenarios of stenosis severity, on the diagnostic parameters. The diagnostic parameters considered in this study include an established index, FFR and two recently developed parameters: Pressure Drop Coefficient (CDP) and Lesion Flow Coefficient (LFC). The parameters were assessed for rigid artery (RR; signifying high plaque elasticity), compliant artery with calcified plaque (CC; intermediate plaque elasticity) and compliant artery with smooth muscle cell proliferation (CS; low plaque elasticity), with varying degrees of epicardial stenosis. A hyperelastic Mooney-Rivlin model was used to model the arterial wall and plaque materials. Blood was modeled as a shear thinning, non-Newtonian fluid using the Carreau model. The arterial wall compliance was evaluated using the finite element method. The present study found that, with an increase in stenosis severity, FFR decreased whereas CDP and LFC increased. The cutoff value of 0.75 for FFR was observed at 78.7% area stenosis for RR, whereas for CC and CS the cutoff values were obtained at higher stenosis severities of 81.3% and 82.7%, respectively. For a fixed stenosis, CDP value decreased and LFC value increased with a decrease in plaque elasticity (RR to CS). We conclude that the differences in diagnostic parameters with compliance at intermediate stenosis (78.7-82.7% area blockage) could lead to misinterpretation of the stenosis severity. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Combined aerobic and resistance exercise training decreases peripheral but not central artery wall thickness in subjects with type 2 diabetes.

    NARCIS (Netherlands)

    Schreuder, T.H.A.; Munckhof, I.C.L. van den; Poelkens, F.; Hopman, M.T.; Thijssen, D.H.

    2015-01-01

    OBJECTIVE: Little is known about the impact of exercise training on conduit artery wall thickness in type 2 diabetes. We examined the local and systemic impact of exercise training on superficial femoral (SFA), brachial (BA), and carotid artery (CA) wall thickness in type 2 diabetes patients and con

  14. Combined aerobic and resistance exercise training decreases peripheral but not central artery wall thickness in subjects with type 2 diabetes.

    NARCIS (Netherlands)

    Schreuder, T.H.A.; Munckhof, I.C.L. van den; Poelkens, F.; Hopman, M.T.; Thijssen, D.H.

    2015-01-01

    OBJECTIVE: Little is known about the impact of exercise training on conduit artery wall thickness in type 2 diabetes. We examined the local and systemic impact of exercise training on superficial femoral (SFA), brachial (BA), and carotid artery (CA) wall thickness in type 2 diabetes patients and

  15. A NEW UNSTEADY THREE DIMENSIONAL MODEL FOR MACROMOLECULAR TRANSPORT AND WATER FILTRATION ACROSS THE ARTERIAL WALL

    Institute of Scientific and Technical Information of China (English)

    黄浩; 温功碧

    2001-01-01

    A new unsteady three-dimensional convective-diffusive mathematical model for the transportation of macromolecules and water across the arterial wall was proposed . After the formation of leaky junctions due to the mitosis of endothelial cell of the arterial wall, the macromolecular transport happens surrounding the leaky cells. The arterial wall was divided into four layers: the endothelial layer, the subendothelial intima, the internal elastic lamina and the media for the convenience of research. The time-dependent concentration growth,the effect of the shape of endothelial cell and the effect of physiological parameters were analyzed. The analytical solution of velocity field and pressure field of water flow across the arterial wall were obtained; and concentration distribution of three macromolecules ; LDL,HRP and Albumin, were calculated with numerical simulation method. The new theory predicts, the maximum and distribution areas of time dependent concentration with round shape endothelial cell are both larger than that with ellipse-shape endothelial cell. The model also predicts the concentration growth is much alike that of a two-dimensional model and it shows that the concentration reaches its peak at the leaky junction where atherosclerotic formation frequently occurs and falls down rapidly in a limited area beginning from its earlier time growth to the state when macromolecular transfer approaches steadily. These predictions of the new model are in agreement with the experimental observation for the growth and concentration distribution of LDL and Albumin.

  16. Altered Metabolism of LDL in the Arterial Wall Precedes Atherosclerosis Regression

    DEFF Research Database (Denmark)

    Bartels, Emil D.; Christoffersen, Christina; Lindholm, Marie W.

    2015-01-01

    Rationale: Plasma cholesterol lowering is beneficial in patients with atherosclerosis. However, it is unknown how it affects entry and degradation of low-density lipoprotein (LDL) particles in the lesioned arterial wall. Objective: We studied the effect of lipid-lowering therapy on LDL permeability...

  17. A New High-Resolution Spectral Approach to Noninvasively Evaluate Wall Deformations in Arteries

    Directory of Open Access Journals (Sweden)

    Ivonne Bazan

    2014-01-01

    Full Text Available By locally measuring changes on arterial wall thickness as a function of pressure, the related Young modulus can be evaluated. This physical magnitude has shown to be an important predictive factor for cardiovascular diseases. For evaluating those changes, imaging segmentation or time correlations of ultrasonic echoes, coming from wall interfaces, are usually employed. In this paper, an alternative low-cost technique is proposed to locally evaluate variations on arterial walls, which are dynamically measured with an improved high-resolution calculation of power spectral densities in echo-traces of the wall interfaces, by using a parametric autoregressive processing. Certain wall deformations are finely detected by evaluating the echoes overtones peaks with power spectral estimations that implement Burg and Yule Walker algorithms. Results of this spectral approach are compared with a classical cross-correlation operator, in a tube phantom and “in vitro” carotid tissue. A circulating loop, mimicking heart periods and blood pressure changes, is employed to dynamically inspect each sample with a broadband ultrasonic probe, acquiring multiple A-Scans which are windowed to isolate echo-traces packets coming from distinct walls. Then the new technique and cross-correlation operator are applied to evaluate changing parietal deformations from the detection of displacements registered on the wall faces under periodic regime.

  18. A New High-Resolution Spectral Approach to Noninvasively Evaluate Wall Deformations in Arteries

    Science.gov (United States)

    Bazan, Ivonne; Negreira, Carlos; Ramos, Antonio; Brum, Javier; Ramirez, Alfredo

    2014-01-01

    By locally measuring changes on arterial wall thickness as a function of pressure, the related Young modulus can be evaluated. This physical magnitude has shown to be an important predictive factor for cardiovascular diseases. For evaluating those changes, imaging segmentation or time correlations of ultrasonic echoes, coming from wall interfaces, are usually employed. In this paper, an alternative low-cost technique is proposed to locally evaluate variations on arterial walls, which are dynamically measured with an improved high-resolution calculation of power spectral densities in echo-traces of the wall interfaces, by using a parametric autoregressive processing. Certain wall deformations are finely detected by evaluating the echoes overtones peaks with power spectral estimations that implement Burg and Yule Walker algorithms. Results of this spectral approach are compared with a classical cross-correlation operator, in a tube phantom and “in vitro” carotid tissue. A circulating loop, mimicking heart periods and blood pressure changes, is employed to dynamically inspect each sample with a broadband ultrasonic probe, acquiring multiple A-Scans which are windowed to isolate echo-traces packets coming from distinct walls. Then the new technique and cross-correlation operator are applied to evaluate changing parietal deformations from the detection of displacements registered on the wall faces under periodic regime. PMID:24688596

  19. Prostanoid Receptors in the Human Vascular Wall

    Directory of Open Access Journals (Sweden)

    Xavier Norel

    2007-01-01

    Full Text Available The mechanisms involved in vascular homeostasis and disease are mostly dependent on the interactions between blood, vascular smooth muscle, and endothelial cells. There is an accumulation of evidence for the involvement of prostanoids, the arachidonic acid metabolites derived from the cyclooxygenase enzymatic pathway, in physiological and/or pathophysiological conditions. In humans, the prostanoids activate different receptors. The classical prostanoid receptors (DP, EP1–4, FP, IP, and TP are localized at the cell plasma or nuclear membrane. In addition, CRTH2 and the nuclear PPAR receptors are two other targets for prostanoids, namely, prostacyclin (PGI2 or the natural derivatives of prostaglandin D2. While there is little information on the role of CRTH2, there are many reports on PPAR activation and the consecutive expression of genes involved in the human vascular system. The role of the classical prostanoid receptors stimulated by PGI2 and thromboxane in the control of the vascular tone has been largely documented, whereas the other receptor subtypes have been overlooked. There is now increasing evidence that suggests a role of PGE2 and the EP receptor subtypes in the control of the human vascular tone and remodeling of the vascular wall. These receptors are also present on leukocytes and platelets, and they are implicated in most of the inflammatory processes within the vascular wall. Consequently, the EP receptor subtypes or isoforms would provide a novel and specific cardiovascular therapeutic approach in the near future.

  20. Automatic airway-artery analysis on lung CT to quantify airway wall thickening and bronchiectasis

    DEFF Research Database (Denmark)

    Perez-Rovira, Adria; Kuo, Wieying; Petersen, Jens;

    2016-01-01

    area percentage (WAP), wall thickness ratio (WTR), and airway diameters. Results: The method was thoroughly evaluated using 8000 manual annotations of airway-artery pairs from 24 full-inspiration pediatric CT scans (12 diseased and 12 controls). Limits of agreement between the automatically...... and manually measured diameters were comparable to interobserver limits of agreement. Differences in automatically obtained WAR, AAR, WAP, and WTR between bronchiectatic subjects and controls were similar as when manual annotations were used: WAR and outer AAR were significantly higher in the bronchiectatic......Purpose: Bronchiectasis and airway wall thickening are commonly assessed in computed tomography (CT) by comparing the airway size with the size of the accompanying artery. Thus, in order to automate the quantification of bronchiectasis and wall thickening following a similar principle...

  1. Hypotrophy of conduit artery walls of the offspring of nitric oxide-defective rats.

    Science.gov (United States)

    Kristek, F; Gerová, M

    2004-04-01

    The objective of the present study was to investigate the structure of the arterial walls of the offspring stemming from nitric oxide (NO)-defective hypertensive parents. The parents were treated with NG-nitro-L-arginine methyl ester (40 mg kg-1 day-1) for 5 weeks. Blood pressure was measured noninvasively in six 30-day-old rats and nine age-matched controls. The cardiovascular system was perfused with glutaraldehyde at 120 mmHg. The thoracic aorta and carotid artery were processed for electron microscopy, and geometry was determined by light microscopy. Endothelial cells, smooth muscle cells (SMC) and extracellular matrix (ECM) were determined by the point counting method in electron micrographs of the carotid artery. The blood pressure of experimental offspring was 150.0 +/- 2.3 vs 104.6 +/- 2.1 mmHg (P hypotrophy. The wall thickness (tunica intima and media) of the thoracic aorta and carotid artery of experimental offspring was decreased to 78.9% (P < 0.01) and 83.8% (P < 0.01), respectively, compared to controls, as confirmed by a respective cross-sectional area of 85.3% (P < 0.01) and 84.1% (P < 0.01). The wall thickness/inner diameter ratio was reduced to 75% (P < 0.01) in the thoracic artery and to 81.5% (P < 0.01) in the carotid artery. No change in endothelial cell volume density or ECM was observed in the tunica intima of the carotid artery, and SMC volume density was lower in the tunica media (37.6 +/- 0.9 vs 44.7 +/- 1.1% for controls, P < 0.01), indicating compromised SMC development. Interference with arginine metabolism, a decrease in NO, and other factors are possible mechanisms underlying the structural alterations of the cardiovascular system of offspring from NO-defective hypertensive rats.

  2. Simulation of stent deployment in a realistic human coronary artery

    NARCIS (Netherlands)

    F.J.H. Gijsen (Frank); F. Migliavacca (Francesco); S. Schievano (Silvia); L. Socci (Laura); L. Petrini (Lorenza); A. Thury (Attila); J.J. Wentzel (Jolanda); A.F.W. van der Steen (Ton); P.W.J.C. Serruys (Patrick); G. Dubini (Gabriele)

    2008-01-01

    textabstractBackground: The process of restenosis after a stenting procedure is related to local biomechanical environment. Arterial wall stresses caused by the interaction of the stent with the vascular wall and possibly stress induced stent strut fracture are two important parameters. The knowledg

  3. Targeting novel antigens in the arterial wall in thromboangiitis obliterans.

    Directory of Open Access Journals (Sweden)

    Murat Akkus

    2010-06-01

    Full Text Available Thromboangiitis obliterans is an inflammatory disease possibly resulting from cigarette smoking as a primary etiologic factor, perhaps as a delayed type of hypersensitivity or toxic angiitis. As little is known about the pathogenesis of the disease, we aimed to determine novel antigens that might be responsible from the local inflammatory reactions and structural changes observed in this disease. An indirect immunoperoxidase technique is used to examine the tissue samples obtained from the dorsalis pedis artery of affected individuals with twenty monoclonal antibodies. Among these several antigens which are not previously reported in TAO like CD34, CD44 and CD90 were determined in the tissue samples examined. On the other hand, many other antigens like cytokine/chemokine receptors, several enzymes and leukocyte/lymphocyte antigens were lacking giving some clues about the local pathological reactions. We briefly discussed our findings for several critical antigens those first described in the present work, possibly having roles in the development of the disease. Expression of the CD90/CD11c receptor/ligand pair seems to play an important role in mononuclear cell recruitment to the damage site. Vascular invasion of not only tunica intima but also the tunica media in affected vessels is clearly demonstrated using endothelial cell specific antigens.

  4. Serum carotenoids reduce progression of early atherosclerosis in the carotid artery wall among Eastern Finnish men.

    Directory of Open Access Journals (Sweden)

    Jouni Karppi

    Full Text Available BACKGROUND: Several previous epidemiologic studies have shown that high blood levels of carotenoids may be protective against early atherosclerosis, but results have been inconsistent. We assessed the association between atherosclerotic progression, measured by intima-media thickness of the common carotid artery wall, and serum levels of carotenoids. METHODS: We studied the effect of carotenoids on progression of early atherosclerosis in a population-based study. The association between concentrations of serum carotenoids, and intima-media thickness of the common carotid artery wall was explored in 840 middle-aged men (aged 46-65 years from Eastern Finland. Ultrasonography of the common carotid arteries were performed at baseline and 7-year follow-up. Serum levels of carotenoids were analyzed at baseline. Changes in mean and maximum intima media thickness of carotid artery wall were related to baseline serum carotenoid levels in covariance analyses adjusted for covariates. RESULTS: In a covariance analysis with adjustment for age, ultrasound sonographer, maximum intima media thickness, examination year, body mass index, systolic blood pressure, smoking, physical activity, serum LDL cholesterol, family history of coronary heart disease, antihypertensive medication and serum high sensitivity C-reactive protein, 7-year change in maximum intima media thickness was inversely associated with lycopene (p = 0.005, α-carotene (p = 0.002 and β-carotene (p = 0.019, respectively. CONCLUSIONS: The present study shows that high serum concentrations of carotenoids may be protective against early atherosclerosis.

  5. Artery wall layer dimensions during normal pregnancy: a longitudinal study using noninvasive high-frequency ultrasound.

    Science.gov (United States)

    Akhter, Tansim; Larsson, Anders; Larsson, Marita; Wikström, Anna-Karin; Naessen, Tord

    2013-01-15

    The vascular effects of normal pregnancy were investigated by estimating the intima and media thicknesses of the common carotid artery separately using 22-MHz ultrasound (Collagenoson, Meudt, Germany) in 57 healthy women with normal pregnancies and pregnancy outcomes, in all three trimesters and at 1 yr postpartum. A thick intima, thin media, and high intima-to-media (I/M) ratio are signs of a less healthy artery wall. Mean artery wall layer dimensions remained fairly constant during pregnancy, but the intima thickness and I/M thickness ratio appeared to improve (decrease) postpartum (P blood pressure in the first trimester were associated with higher I/M ratios, especially in the second trimester, whereas higher serum estradiol levels were significantly associated with a lower I/M ratio. Changes from the first to second trimesters in I/M ratio, taking into account differential changes in intima and media thickness, were significantly (P pregnancy appeared to improve postpartum. However, higher age, body mass index, or blood pressure and lower serum estradiol levels in the first trimester appeared to negatively affect the artery wall, strongly suggesting that pregnancy has negative vascular effects in some women. A less likely explanation involves possible adaptation to physiological changes during and after pregnancy.

  6. High-resolution Magnetic Resonance Vessel Wall Imaging for Intracranial Arterial Stenosis

    Institute of Scientific and Technical Information of China (English)

    Xian-Jin Zhu; Wu Wang; Zun-Jing Liu

    2016-01-01

    Objective:To discuss the feasibility and clinical value of high-resolution magnetic resonance vessel wall imaging (HRMR VWI) for intracranial arterial stenosis.Date Sources:We retrieved information from PubMed database up to December 2015,using various search terms including vessel wall imaging (VWI),high-resolution magnetic resonance imaging,intracranial arterial stenosis,black blood,and intracranial atherosclerosis.Study Selection:We reviewed peer-reviewed articles printed in English on imaging technique of VWI and characteristic findings of various intracranial vasculopathies on VWI.We organized this data to explain the value of VWI in clinical application.Results:VWI with black blood technique could provide high-quality images with submillimeter voxel size,and display both the vessel wall and lumen of intracranial artery simultaneously.Various intracranial vasculopathies (atherosclerotic or nonatherosclerotic) had differentiating features including pattern of wall thickening,enhancement,and vessel remodeling on VWI.This technique could be used for determining causes of stenosis,identification of stroke mechanism,risk-stratifying patients,and directing therapeutic management in clinical practice.In addition,a new morphological classification based on VWI could be established for predicting the efficacy of endovascular therapy.Conclusions:This review highlights the value of HRMR VWI for discrimination of different intracranial vasculopathies and directing therapeutic management.

  7. Hypotrophy of conduit artery walls of the offspring of nitric oxide-defective rats

    OpenAIRE

    Kristek F.; Gerová M.

    2004-01-01

    The objective of the present study was to investigate the structure of the arterial walls of the offspring stemming from nitric oxide (NO)-defective hypertensive parents. The parents were treated with N G-nitro-L-arginine methyl ester (40 mg kg-1 day-1) for 5 weeks. Blood pressure was measured noninvasively in six 30-day-old rats and nine age-matched controls. The cardiovascular system was perfused with glutaraldehyde at 120 mmHg. The thoracic aorta and carotid artery were processed for elect...

  8. Unravelling the collagen network of the arterial wall

    NARCIS (Netherlands)

    Beenakker, Jan Willem Maria

    2012-01-01

    Although the extracellular matrix (ECM) is the key determinant of the mechanical behavior and stability of tissue, remarkably little is known on this tissue component. Most biomedical research on the human aorta focuses on biochemical analysis of tissues or the properties of specific cells in the ao

  9. Dual stack black blood carotid artery CMR at 3T: Application to wall thickness visualization

    Directory of Open Access Journals (Sweden)

    Marx Nikolaus

    2009-11-01

    Full Text Available Abstract Background The increasing understanding of atherosclerosis as an important risk factor for the development of acute ischemic events like ischemic stroke has stimulated increasing interest in non-invasive assessment of the structure, composition and burden of plaque depositions in the carotid artery wall. Vessel wall imaging by means of cardiovascular magnetic resonance (CMR is conventionally done by 2D dual inversion recovery (DIR techniques, which often fail in covering large volumes of interest as required in plaque burden assessment. Although the technique has been extended to 2D multislice imaging, its straight extension to 3D protocols is still limited by the prolonged acquisition times and incomplete blood suppression. A novel approach for rapid overview imaging of large sections of the carotid artery wall at isotropic spatial resolutions is presented, which omits excitation of the epiglottis. By the interleaved acquisition of two 3D stacks with the proposed motion sensitized segmented steady-state black-blood gradient echo technique (MSDS the coverage of the carotid artery trees on both sides in reasonable scan times is enabled. Results 10 patients were investigated with the proposed technique and compared to conventional transversal DIR turbo spin and gradient echo approaches centered at the height of the carotid bifurcation. In all MSDS experiments sufficient black-blood contrast could be obtained over the entire covered volumes. The contrast to noise ratio between vessel and suppressed blood was improved by 73% applying the motion sensitizing technique. In all patients the suspicious areas of vessel wall thickening could be clearly identified and validated by the conventional local imaging approach. The average assessable vessel wall segment length was evaluated to be 18 cm. While in 50% of the cases motion artifacts could be appreciated in the conventional images, none were detected for the MSDS technique. Conclusion The

  10. Arterial wall stiffness in patients with essential hypertension at young age

    Directory of Open Access Journals (Sweden)

    Kolesnik E.L.

    2014-11-01

    Full Text Available Research objective was investigating arterial wall stiffness in patients with hypertension at young age and assessing the relationship between subclinical target organs damage and ambulatory blood pressure monitoring (ABPM parameters. 30 male patients aged 18-35 years with essential hypertension stage I and II, hypertension 1 and 2nd grade were surveyed. The examination included general clinical methods, echocardiography, ABPM and suprasystolic sfigmography. It was found that the pulse wave velocity (PWVao (r = 0,557 p <0,01, central aortic blood pressure (SBPao (r = 0,492 p <0,01 and augmentation index (AIxao (r = 0,489 p <0.01 significantly increased with the pa¬tients’ age. Abdominal obesity (r = 0,566 p <0,01 and BMI (r = 0,599 p <0,01 impacted on the PWVao acceleration. Increasing of the left ventricular mass index (LVMI is highly associated with SBPao (r = 0,506 p <0,05 and PWVao (r = 0,434 p <0,05. According to ABPM the most significant correlation with arterial wall stiffness parameters demon¬strated diastolic blood pressure (DBP daytime level (AIxao (r = 0,418 p <0,01, with PWVao (r = 0,699 p <0.01 and SBPao (r = 0,695 p <0,01. Thus, age, excessive body weight and obesity should be considered as unfavorable factors that worsen arterial wall stiffness in patients with hypertension at the age before 35 years. Increase of DBP levels especially during the day causes maximum negative impact on the arterial wall stiffness parameters according to ABPM. Increased SBPao and PWVao in patients with hypertension at a young age are associated with increased left ventricular mass index.

  11. Quantifying [{sup 18}F]fluorodeoxyglucose uptake in the arterial wall: the effects of dual time-point imaging and partial volume effect correction

    Energy Technology Data Exchange (ETDEWEB)

    Blomberg, Bjoern A. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Odense University Hospital, Department of Nuclear Medicine, Odense (Denmark); Bashyam, Arjun; Ramachandran, Abhinay; Gholami, Saeid; Houshmand, Sina; Salavati, Ali; Werner, Tom; Alavi, Abass [Hospital of the University of Pennsylvania, Department of Radiology, Philadelphia, PA (United States); Zaidi, Habib [Geneva University Hospital, Division of Nuclear Medicine and Molecular Imaging, Geneva (Switzerland); University of Groningen, Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Groningen (Netherlands)

    2015-08-15

    The human arterial wall is smaller than the spatial resolution of current positron emission tomographs. Therefore, partial volume effects should be considered when quantifying arterial wall {sup 18}F-FDG uptake. We evaluated the impact of a novel method for partial volume effect (PVE) correction with contrast-enhanced CT (CECT) assistance on quantification of arterial wall {sup 18}F-FDG uptake at different imaging time-points. Ten subjects were assessed by CECT imaging and dual time-point PET/CT imaging at approximately 60 and 180 min after {sup 18}F-FDG administration. For both time-points, uptake of {sup 18}F-FDG was determined in the aortic wall by calculating the blood pool-corrected maximum standardized uptake value (cSUV{sub MAX}) and cSUV{sub MEAN}. The PVE-corrected SUV{sub MEAN} (pvcSUV{sub MEAN}) was also calculated using {sup 18}F-FDG PET/CT and CECT images. Finally, corresponding target-to-background ratios (TBR) were calculated. At 60 min, pvcSUV{sub MEAN} was on average 3.1 times greater than cSUV{sub MAX} (P <.0001) and 8.5 times greater than cSUV{sub MEAN} (P <.0001). At 180 min, pvcSUV{sub MEAN} was on average 2.6 times greater than cSUV{sub MAX} (P <.0001) and 6.6 times greater than cSUV{sub MEAN} (P <.0001). This study demonstrated that CECT-assisted PVE correction significantly influences quantification of arterial wall {sup 18}F-FDG uptake. Therefore, partial volume effects should be considered when quantifying arterial wall {sup 18}F-FDG uptake with PET. (orig.)

  12. Fluid-structure interaction analysis of bioprosthetic heart valves: Significance of arterial wall deformation.

    Science.gov (United States)

    Hsu, Ming-Chen; Kamensky, David; Bazilevs, Yuri; Sacks, Michael S; Hughes, Thomas J R

    2014-10-01

    We propose a framework that combines variational immersed-boundary and arbitrary Lagrangian-Eulerian (ALE) methods for fluid-structure interaction (FSI) simulation of a bioprosthetic heart valve implanted in an artery that is allowed to deform in the model. We find that the variational immersed-boundary method for FSI remains robust and effective for heart valve analysis when the background fluid mesh undergoes deformations corresponding to the expansion and contraction of the elastic artery. Furthermore, the computations presented in this work show that the arterial wall deformation contributes significantly to the realism of the simulation results, leading to flow rates and valve motions that more closely resemble those observed in practice.

  13. Injection-moulded models of major and minor arteries: the variability of model wall thickness owing to casting technique.

    Science.gov (United States)

    O'Brien, T; Morris, L; O'Donnell, M; Walsh, M; McGloughlin, T

    2005-09-01

    Cardiovascular disease of major and minor arteries is a common cause of death in Western society. The wall mechanics and haemodynamics within the arteries are considered to be important factors in the disease formation process. This paper is concerned with the development of an efficient computer-integrated technique to manufacture idealized and realistic models of diseased major and minor arteries from radiological images and to address the issue of model wall thickness variability. Variations in wall thickness from the original computer models to the final castings are quantified using a CCD camera. The results found that wall thickness variation from the major and minor idealized artery models to design specification were insignificant, up to a maximum of 16 per cent. In realistic models, however, differences were up to 23 per cent in the major arterial models and 58 per cent in the minor arterial models, but the wall thickness variability remained within the limits of previously reported wall thickness results. It is concluded that the described injection moulding procedure yields idealized and realistic castings suitable for use in experimental investigations, with idealized models giving better agreement with design. Wall thickness is variable and should be assessed after the models are manufactured.

  14. Arterial wall mechanics as a function of heart rate: role of vascular smooth muscle

    Energy Technology Data Exchange (ETDEWEB)

    Salvucci, Fernando Pablo; Schiavone, Jonathan; Craiem, Damian; Barra, Juan Gabriel [Facultad de Ingenieria y Ciencias Exactas y Naturales, Universidad Favaloro Av. Belgrano 1723 - Buenos Aires (Argentina)

    2007-11-15

    Vascular wall viscoelasticity can be evaluated using a first-order lumped model. This model consists of a spring with elastic constant E and a dashpot with viscous constant {eta}. More importantly, this viscoelastic model can be fitted in-vivo measuring arterial pressure and diameter. The aim of this work is to analyze the influence of heart rate over E and {eta}. In two anesthetized sheep, diameter in thoracic aorta and intravascular pressure has been registered. The right atrium was connected to a programmable stimulator through a pair of pace-maker wires to produce changes in stimulation heart rate (HR) from 80 to 160 bpm. Additionally, local activation of vascular smooth muscle was induced with phenylephrine. After converting pressure and diameter signals into stress and strain respectively, E y {eta} were calculated in control state and during muscle activation. The elastic modulus E did not present significant changes with heart rate. The viscous modulus {eta} decreased 49% with a two-fold acceleration in heart rate from 80 to 160 bpm. However, the product {eta} HR remained stable. The viscous modulus {eta} increased 39% with smooth muscle activation. No significant pressure changes were registered during the experiment. The contractile action of vascular smooth muscle could contribute to increasing arterial wall viscosity. The decrease of {eta} when HR increased might be related to smooth muscle relaxation mediated by endothelium activity, which was stimulated by flow increase. We conclude that HR can modulate arterial wall viscoelasticity through endothelium-dependent mechanisms.

  15. [Hematoma of the abdominal wall. A case report: pitfall of Seldinger method via femoral artery].

    Science.gov (United States)

    Hiramatsu, Hisaya; Sugiura, Yasushi; Takeda, Ririko; Nanba, Hiroki

    2009-02-01

    We reported a case of an abdominal wall hematoma which caused by Seldinger method via the femoral artery. A 48-year-old female, suffered from direct carotid cavernous fistula, was treated by transfemoral transvenous embolization (TVE). The whole procedure was completed without difficulty except minor resistance of guide wire manipulation during left femoral artery catheterization. Four hours later, the patient became hypotensive and showed the sign of impending shock without definitive causes. Nine hours after the embolization a huge hematoma of the abdominal wall was found. It required the total 1200 m/ of blood transfusion before her blood pressure returned to normal. She recovered fully from this event and discharged uneventfully. There is a speculation that a deep circumflex iliac artery (DCIA) was injured with an angle-shaped guide wire and bled into the abdominal wall. And subsequent systemic heparinization prevented the coagulation process, resulting a large hematoma. Anatomically, an angle-shaped guide wire is easily able to migrate into DCIA. To prevent a vascular injury, it is very important to manipulate a guide wire under fluoroscopic control and to select a J-shaped guide wire instead of an angle-shaped one.

  16. Finite element formulation and analysis for an arterial wall with residual and active stresses.

    Science.gov (United States)

    Kida, Naoki; Adachi, Taiji

    2015-08-01

    In this study, for predicting arterial function and pathogenesis from a mechanical viewpoint, we develop a continuum mechanical model of an arterial wall that embodies residual and active stresses following a traditional anisotropic passive constitutive law. The residual and active stresses are incorporated into finite element methods based on a two-field variational principle described in the Lagrangian form. The linearisation of nonlinear weak-form equations derived from this variational principle is then described for developing an original finite element algorithm. Numerical simulations reveal the following: (i) residual stresses lead to a reduction in stress gradient regardless of the magnitude of external load; (ii) active stresses help homogenise stress distribution under physiological external load, but this homogeneity collapses under pathological external load; (iii) when residual and active stresses act together, the effect of the residual stresses is relatively obscured by that of the active stresses. We conclude that residual stresses have minor but persistent mechanical effects on the arterial wall under both physiological and pathological external loads; active stresses play an important role in the physiological functions and pathogenesis of arteries, and the mechanical effect of residual stresses is dependent on the presence/absence of active stresses.

  17. Thickening of the pulmonary artery wall in acute intramural hematoma of the ascending aorta

    Directory of Open Access Journals (Sweden)

    Lardani Héctor

    2007-01-01

    Full Text Available Abstract Background The occurrence of pulmonary artery obstruction in the course of acute aortic dissection is an unusual complication. The mechanism implicated is the rupture of the outer layer of the aorta and the subsequent hemorrhage into the adventitia of the pulmonary artery that causes its wall thickening and, at times, produces extrinsic obstruction of the vessel. There are no reports of this complication in acute intramural hematoma. Case presentation An 87-year-old woman was admitted to the hospital in shock after having had severe chest pain followed by syncope. An urgent transesophageal echocardiogram revealed the presence of acute intramural hematoma, no evidence of aortic dissection, severe pericardial effusion with cardiac tamponade, and periaortic hematoma that involved the pulmonary artery generating circumferential wall thickening of its trunk and right branch with no evidence of flow obstruction. Urgent surgery was performed but the patient died in the operating room. The post mortem examination, in the operating room, confirmed that there was an extensive hematoma around the aorta and beneath the adventitial layer of the pulmonary artery, with no evidence of flow obstruction. Conclusion This is the first time that this rare complication is reported in the scenario of acute intramural hematoma and with the transesophageal echocardiogram as the diagnostic tool.

  18. Copper dependence of angioproliferation in pulmonary arterial hypertension in rats and humans.

    Science.gov (United States)

    Bogaard, Harm J; Mizuno, Shiro; Guignabert, Christophe; Al Hussaini, Aysar A; Farkas, Daniela; Ruiter, Gerrina; Kraskauskas, Donatas; Fadel, Elie; Allegood, Jeremy C; Humbert, Marc; Vonk Noordegraaf, Anton; Spiegel, Sarah; Farkas, Laszlo; Voelkel, Norbert F

    2012-05-01

    Obliteration of the vascular lumen by endothelial cell growth is a hallmark of many forms of severe pulmonary arterial hypertension. Copper plays a significant role in the control of endothelial cell proliferation in cancer and wound-healing. We sought to determine whether angioproliferation in rats with experimental pulmonary arterial hypertension and pulmonary microvascular endothelial cell proliferation in humans depend on the proangiogenic action of copper. A copper-depleted diet prevented, and copper chelation with tetrathiomolybdate reversed, the development of severe experimental pulmonary arterial hypertension. The copper chelation-induced reopening of obliterated vessels was caused by caspase-independent apoptosis, reduced vessel wall cell proliferation, and a normalization of vessel wall structure. No evidence was found for a role of super oxide-1 inhibition or lysyl-oxidase-1 inhibition in the reversal of angioproliferation. Tetrathiomolybdate inhibited the proliferation of human pulmonary microvascular endothelial cells, isolated from explanted lungs from control subjects and patients with pulmonary arterial hypertension. These data suggest that the inhibition of endothelial cell proliferation by a copper-restricting strategy could be explored as a new therapeutic approach in pulmonary arterial hypertension. It remains to be determined, however, whether potential toxicity to the right ventricle is offset by the beneficial pulmonary vascular effects of antiangiogenic treatment in patients with pulmonary arterial hypertension.

  19. [Large artery wall properties in dialyse and renal transplant patients with normal blood pressure].

    Science.gov (United States)

    Posadzy-Małaczyńska, Anna; Kosch, Marcus; Hausberg, Martin; Rahn, Karl H; Małaczyński, Paweł; Głuszek, Jerzy; Tykarski, Andrzej

    2004-01-01

    Structural and mechanical properties of the arterial wall are altered in patients with renal failure. Age and hypertension are known to affect the vessel wall structure. Aging process of arterial wall appears to be accelerated in patients with end-stage renal failure. The mechanisms responsible for reduced arterial compliance and distensibility in dialyse patients and renal transplant recipients without hypertension remain to be evaluated. 20 normotensive dialyse patients (D), 20 normotensive renal transplant recipients (T) and 20 healthy volunteers (N) matched for age, sex and blood pressure as controls were enrolled in to the study. Patients with cardiovascular risk factors and diabetes were excluded. The arterial blood pressure of all patients placed below 140/90 mmHg. The dialyse patients and renal transplant recipients were eligible for the study if the serum creatinine level was below 2 mg/dl. In all subjects, fasting concentrations of serum creatinine, total cholesterol, HDL-cholesterol, LDL-cholesterol, hemoglobin and glucose were determined at enrollment to the study. Long-term immunosuppression consisted of cyclosporine and prednisolone. Blood pressure was measured using an automatic sphygmomanometer (Criticon Dinamap model 1846 SX). Pulse wave velocity (PWV) was evaluated using non-invasive automatic Complior device. The vessel wall properties of the left common carotid artery were studied using multigate pulsed Doppler's system (Pie Medical Equipment BV Maastricht, The Netherlands). The frequency of transducer used was 7.5 MHz. With this non-invasive method, the end-diastolic diameter (d) and the systolic increase of vessel diameter (distension delta d) were measured using ECG trigger. From these data relative systolic increase of vessel diameter (delta d/d) and arterial wall distensibility coefficient (DC) were calculated. Simultaneously with the ultrasound measurements at the left common carotid artery carotid pulse waveforms are recorded using

  20. Pulmonary arterial wall distensibility assessed by intravascular ultrasound in children with congenital heart disease : an indicator for pulmonary vascular disease?

    NARCIS (Netherlands)

    Berger, Rolf M F; Cromme-Dijkhuis, Adri H; Hop, Wim C J; Kruit, Marco N; Hess, John; Berger, Rudolphus

    2002-01-01

    BACKGROUND: Both pulmonary hypertension and pulmonary overflow are associated with functional and structural changes of the pulmonary arterial wall. Current techniques to evaluate the pulmonary vasculature neglect the pulsatile nature of pulmonary flow. STUDY OBJECTIVES: To determine whether the dyn

  1. Hypotrophy of conduit artery walls of the offspring of nitric oxide-defective rats

    Directory of Open Access Journals (Sweden)

    Kristek F.

    2004-01-01

    Full Text Available The objective of the present study was to investigate the structure of the arterial walls of the offspring stemming from nitric oxide (NO-defective hypertensive parents. The parents were treated with N G-nitro-L-arginine methyl ester (40 mg kg-1 day-1 for 5 weeks. Blood pressure was measured noninvasively in six 30-day-old rats and nine age-matched controls. The cardiovascular system was perfused with glutaraldehyde at 120 mmHg. The thoracic aorta and carotid artery were processed for electron microscopy, and geometry was determined by light microscopy. Endothelial cells, smooth muscle cells (SMC and extracellular matrix (ECM were determined by the point counting method in electron micrographs of the carotid artery. The blood pressure of experimental offspring was 150.0 ± 2.3 vs 104.6 ± 2.1 mmHg (P < 0.01 for the controls and their heart/body weight ratio of 3.9 ± 0.1 vs 4.4 ± 0.2 (P < 0.05 for the controls indicated cardiac hypotrophy. The wall thickness (tunica intima and media of the thoracic aorta and carotid artery of experimental offspring was decreased to 78.9% (P < 0.01 and 83.8% (P < 0.01, respectively, compared to controls, as confirmed by a respective cross-sectional area of 85.3% (P < 0.01 and 84.1% (P < 0.01. The wall thickness/inner diameter ratio was reduced to 75% (P < 0.01 in the thoracic artery and to 81.5% (P < 0.01 in the carotid artery. No change in endothelial cell volume density or ECM was observed in the tunica intima of the carotid artery, and SMC volume density was lower in the tunica media (37.6 ± 0.9 vs 44.7 ± 1.1% for controls, P < 0.01, indicating compromised SMC development. Interference with arginine metabolism, a decrease in NO, and other factors are possible mechanisms underlying the structural alterations of the cardiovascular system of offspring from NO-defective hypertensive rats.

  2. Plasma levels of the arterial wall protein fibulin-1 are associated with carotid-femoral pulse wave velocity

    DEFF Research Database (Denmark)

    Laugesen, Esben; Høyem, Pernille; Christiansen, Jens Sandahl;

    2013-01-01

    -associated extracellular matrix protein, fibulin-1, was recently found in higher concentrations in the arterial wall and in plasma in patients with long duration type 2 diabetes. Furthermore, plasma fibulin-1 independently predicted total mortality and was associated with pulse pressure, an indirect measure of arterial...

  3. Posterior Wall Capture and Femoral Artery Stenosis Following Use of StarClose Closing Device: Diagnosis and Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Stefanczyk, Ludomir [Medical University of Lodz, First Department of Radiology and Diagnostic Imaging (Poland); Elgalal, Marcin T., E-mail: telgalal@yahoo.co.uk [Medical University of Lodz, Second Department of Radiology and Diagnostic Imaging (Poland); Szubert, Wojciech; Grzelak, Piotr [Medical University of Lodz, First Department of Radiology and Diagnostic Imaging (Poland); Szopinski, Piotr [Institute of Haematology and Transfusion Medicine, Department of Vascular Surgery (Poland); Majos, Agata [Medical University of Lodz, Second Department of Radiology and Diagnostic Imaging (Poland)

    2013-10-15

    A case of femoral artery obstruction following application of a StarClose type arterial puncture closing device (APCD) is presented. Ultrasonographic and angiographic imaging of this complication was obtained. The posterior wall of the vessel was accidentally caught in the anchoring element of the nitinol clip. This complication was successfully resolved by endovascular treatment and the implantation of a stent.

  4. Non-Newtonian effects of blood on LDL transport inside the arterial lumen and across multi-layered arterial wall with and without stenosis

    Science.gov (United States)

    Deyranlou, Amin; Niazmand, Hamid; Sadeghi, Mahmood-Reza; Mesri, Yaser

    2016-06-01

    Blood non-Newtonian behavior on low-density lipoproteins (LDL) accumulation is analyzed numerically, while fluid-multilayered arteries are adopted for nonstenotic and 30%-60% symmetrical stenosed models. Present model considers non-Newtonian effects inside the lumen and within arterial layers simultaneously, which has not been examined in previous studies. Navier-Stokes equations are solved along with the mass transport convection-diffusion equations and Darcy’s model for species transport inside the luminal flow and across wall layers, respectively. Carreau model for the luminal flow and the modified Darcy equation for the power-law fluid within arterial layers are employed to model blood rheological characteristics, appropriately. Results indicate that in large arteries with relatively high Reynolds number Newtonian model estimates LDL concentration patterns well enough, however, this model seriously incompetent for regions with low WSS. Moreover, Newtonian model for plasma underestimates LDL concentration especially on luminal surface and across arterial wall. Therefore, applying non-Newtonian model seems essential for reaching to a more accurate estimation of LDL distribution in the artery. Finally, blood flow inside constricted arteries demonstrates that LDL concentration patterns along the stenoses inside the luminal flow and across arterial layers are strongly influenced as compared to the nonstenotic arteries. Additionally, among four stenosis severity grades, 40% stenosis is prone to more LDL accumulation along the post-stenotic regions.

  5. SYNERGY OF WALL SHEAR STRESS AND CIRCUMFERENTIAL STRESS IN STRAIGHT ARTERIES

    Institute of Scientific and Technical Information of China (English)

    QIN Kai-rong; XU Zhe; WU Hao; JIANG Zong-lai; LIU Zhao-rong

    2005-01-01

    The Wall Shear Stress (WSS) generated by blood flow and Circumferential Stress (CS) driven by blood pressure have been thought to play an important role in blood flow-dependent phenomena such as angiogenesis, vascular remodeling, and atherosgenesis.The WSS and CS in straight arteries were calculated by measuring the blood pressure, center-line velocity, wall thickness, and radius of vessels.The WSS and CS in the time domain were then decomposed into the amplitude and phase in the frequency domain.The CS amplitude to the WSS amplitude ratio (referred as stress amplitude ratio, Zs) and the phase difference between the CS and the WSS (referred as stress phase difference, SPA) in the frequency domain were calculated to characterize the synergy of the CS and WSS.Numerical results demonstrated that the CS is not in phase with the WSS, a time delay in the time domain or a stress phase difference in the frequency domain between the WSS and the CS exists.Theoretical analysis demonstrated that the Zs and SPA are primarily determined by the local factors (blood viscosity, local inertial effects, local geometry, local elasticity) and the input impedance of whole downstream arterial beds.Because the arterial input impedance has been shown to reflect the physiological and pathological states of whole downstream arterial beds, the stress amplitude ratio Zs and stress phase difference SPA would be thought to be the appropriate indices to reflect the effects of states of whole downstream arterial beds on the local blood flow-dependent phenomena such as angiogenesis, vascular remodeling, and atherosgenesis.

  6. "Sausage-string" appearance of arteries and arterioles can be caused by an instability of the blood vessel wall

    DEFF Research Database (Denmark)

    Jacobsen, Jens Christian Brings; Beierholm, Ulrik; Mikkelsen, Rene

    2002-01-01

    in vascular wall tension. Despite much research, the mechanisms underlying the sausage pattern have remained unknown. Here we present an anisotropic model of the vessel wall and show that the sausage pattern can arise because of an instability of the vessel wall. The model reproduces many of the key features...... phenomenon. Experimental data suggest that the structural changes induced by the instability may cause secondary damage to the wall of small arteries and arterioles in the form of endothelial hyperpermeability followed by local fibrinoid necrosis of the vascular wall....

  7. Interaction of wall shear stress magnitude and gradient in the prediction of arterial macromolecular permeability.

    Science.gov (United States)

    LaMack, Jeffrey A; Himburg, Heather A; Li, Xue-Mei; Friedman, Morton H

    2005-04-01

    Large spatial shear stress gradients have anecdotally been associated with early atherosclerotic lesion susceptibility in vivo and have been proposed as promoters of endothelial cell dysfunction in vitro. Here, experiments are presented in which several measures of the fluid dynamic shear stress, including its gradient, at the walls of in vivo porcine iliac arteries, are correlated against the transendothelial macromolecular permeability of the vessels. The fluid dynamic measurements are based on postmortem vascular casts, and permeability is measured from Evans blue dye (EBD) uptake. Time-averaged wall shear stress (WSS), as well as a new parameter termed maximum gradient stress (MGS) that describes the spatial shear stress gradient due to flow acceleration at a given point, are mapped for each artery and compared on a point-by-point basis to the corresponding EBD patterns. While there was no apparent relation between MGS and EBD uptake, a composite parameter, WSS(-0.11) MGS(0.044), was highly correlated with permeability. Notwithstanding the small exponents, the parameter varied widely within the region of interest. The results suggest that sites exposed to low wall shear stresses are more likely to exhibit elevated permeability, and that this increase is exacerbated in the presence of large spatial shear stress gradients.

  8. Wall shear stress and pressure distribution on aneurysms and infundibulae in the posterior communicating artery bifurcation.

    Science.gov (United States)

    Baek, Hyoungsu; Jayaraman, Mahesh V; Karniadakis, George Em

    2009-12-01

    A growing number of cases of rupture at an infundibulum, progression of infundibulum to a frank aneurysm, and subarachnoid hemorrhage (SAH) in the posterior communicating artery (PCoA) have been reported. Using patient-specific geometric models of the supraclinoid internal carotid artery (ICA) with PCoA infundibulum or aneurysm, high-resolution computational fluid dynamics simulations were performed by solving the Navier-Stokes equations with a spectral/hp element method. Simulation results show that the flow impinges at the distal wall of infundibulum near the outside of the ICA bend and creates a region of higher pressure (4-5 mmHg) surrounded by a band of a high wall shear stress (WSS) (20-30 N/m(2) on average). At the proximal end of the infundibulum, another stagnation area is formed characterized by low WSS (shear index. This impingement region seems to coincide with the locations of the rupture of infundibulae or progression to aneurysms. In addition, the pulsatile flow becomes unstable due to the presence of aneurysms or aneurysm-like infundibulae, and this leads to WSS temporal fluctuations inside the aneurysm, which may accelerate the degenerative processes in the vessel walls.

  9. The Hemodynamic Effects of Blood Flow-Arterial Wall Interaction on Cerebral Aneurysms

    Science.gov (United States)

    Oshima, Marie

    2005-11-01

    Mechanical stresses such as wall shear induced by blood flow play an important role on cardiovascular diseases and cerebral disorders like arterioscleroses and cerebral aneurysm. In order to obtain a better understanding of mechanism of formation, growth, and rupture of cerebral aneurysm, this paper focuses on investigation of cerebral hemodynamics and its effects on aneurismal wall. The paper mainly consists of three parts. Since it is important to obtain the detailed information on the hemodynamic properties in the cerebral circulatory system, the first part discusses a large-scale hemodynamic simulation of the Cerebral Arterial Circle of Willis. The second part presents the simulation and in-vitro experiment of cerebral aneurysm with the consideration of blood flow-arterial wall interaction. Both simulations in the first and the second parts are conducted in a patient specific manner using medical images and also include modeling of boundary conditions to emulate realistic hemodynamic conditions. The present mathematical model, however, includes only macroscopic mechanical functions. Therefore, in the third part, the paper touches upon on future prospects in modeling of microscopic functions such as the effects of endothelial cells and multi physics functions such as physiological effects.

  10. Effect of hypertension on low-density lipoprotein transport within a multi-layered arterial wall: modelling consistent with experiments

    CERN Document Server

    Jesionek, Katarzyna; Kostur, Marcin

    2016-01-01

    The influence of hypertension on low-density lipoproteins intake into the arterial wall is an important factor for understanding mechanisms of atherosclerosis. It has been experimentally observed that the increased pressure leads to the higher level of the LDL inside the wall. In this paper we attempt to construct a model of the LDL transport which reproduces quantitatively experimental outcomes. We supplement the well known four-layer arterial wall model to include two pressure induced effects: the compression of the intima tissue and the increase of the fraction of leaky junctions. We demonstrate that such model can reach the very good agreement with experimental data.

  11. Focal accumulation of an apolipoprotein B-based synthetic oligopeptide in the healing rabbit arterial wall

    Energy Technology Data Exchange (ETDEWEB)

    Shih, I.L.; Lees, R.S.; Chang, M.Y.; Lees, A.M. (Harvard Univ., Boston, MA (USA))

    1990-02-01

    The functions of surface-accessible domains of apolipoprotein (apo) B, the protein moiety of low density lipoprotein (LDL), are unknown, aside from the LDL receptor-binding domain, which lies toward the carboxyl-terminal end of apoB. Since LDL accumulation in arterial lesions does not depend on recognition of LDLs by a cell-surface receptor, we synthesized an oligopeptide with the sequence of the trypsin-accessible domain of apoB that lies closest to the amino-terminal end of the protein and compared its biological activity to that of another synthetic oligopeptide with the sequence of the heparin- and apoB/apoE receptor-binding domains of apoE. (Tyrosine was added at the amino-terminal end of each peptide to facilitate radiolabeling.) The 18-amino acid apoB-based peptide included residues 1000-1016 of apoB, for which no function has been previously described. In radioautographs, the 125I-labeled peptide accumulated focally at the healing edges of regenerating endothelial islands in the balloon-catheter deendothelialized rabbit aorta. In contrast, the 21-residue apoE-based peptide, which included residues 129-148 of apoE, accumulated diffusely and uniformly throughout the deendothelialized areas of the aorta. The data show that focal binding of the apoB-based peptide can delineate arterial lesions and suggest that this arterial wall-binding domain of apoB mediates accumulation of LDLs in arterial lesions.

  12. Wall Imaging for Unilateral Intracranial Vertebral Artery Hypoplasia with Three-dimensional High-isotropic Resolution Magnetic Resonance Images

    Institute of Scientific and Technical Information of China (English)

    Xian-Jin Zhu; Wu Wang; Bin Du; Lei Liu; Xin-Xin He; Li-Bin Hu; Xue-Bin Zhang

    2015-01-01

    Background:There are few studies for evaluating wall characteristics of intracranial vertebral artery hypoplasia (VAH).The aim of this study was to determine wall characteristics of VAH with three-dimensional volumetric isotropic turbo spin echo acquisition (3D VISTA) images and differentiate between acquired atherosclerotic stenosis and VAH.Methods:Thirty patients with suspicious VAH by luminograms were retrospectively enrolled between January 2014 and February 2015.The patients were classified as "acquired atherosclerotic stenosis" or "VAH" based on 3D VISTA images.The wall characteristics of VAH were assessed to determine the presence of atherosclerotic lesions,and the patients were classified into two subgroups (VAH with atherosclerosis and VAH with normal wall).Wall characteristics of basilar arteries and vertebral arteries were also assessed.The clinical and wall characteristics were compared between the two groups.Results:Five of 30 patients with suspicious VAH were finally diagnosed as acquired atherosclerotic stenosis by 3D VISTA images.25 patients were finally diagnosed as VAH including 16 (64.00%) patients with atherosclerosis and 9 (36.00%) patients with normal wall.In the 16 patients with atherosclerosis,plaque was found in 9 patients,slight wall thickening in 6 patients,and thrombus and wall thickening in 1 patient.Compared with VAH patients with normal wall,VAH patients with atherosclerosis showed atherosclerotic basilar arteries and dominant vertebral arteries more frequently (P =0.000).Conclusions:Three-dimensional VISTA images enable differentiation between the acquired atherosclerotic stenosis and VAH.VAH was also prone to atherosclerotic processes.

  13. HUMAN CORONARY ARTERIES- A STUDY BASED ON MICROSCOPY

    Directory of Open Access Journals (Sweden)

    Vijayamma Kunnath Narayanan

    2017-01-01

    Full Text Available BACKGROUND The coronary arteries are the biggest vasa vasora in the body since the heart is considered to be a modified blood vessel. The increased myocardial oxygen demand of the heart is met wholly by two coronary arteries. Hence, patients with coronary artery disease are prone to develop myocardial ischemia. The study is aimed at the structural changes of this vessels in the population of middle Kerala of various age groups from birth to seventy years. MATERIALS AND METHODS The specimen for histological study were fixed in 10% formalin and subjected to tissue processing. The sections were taken at the thickness of 5 microns and stained by using Haematoxylin- Eosin method and Verhoeff’s method for elastic fibers. The thickness of arterial wall were measured using ocular micrometer. RESULTS Structural changes of the three layered vessel walls were observed. Intimal proliferation, splitting, fragmentation and reduplication of internal elastic lamina were the important histological observation in the arterial wall as age advances. It was observed that there was a sixty fold increase in the thickness of intima from foetal to sixth decade of life. Tunica media exhibit a six fold increase in thickness probably due to muscular hypertrophy. The tunica adventitia have a threefold increase in thickness which least compared with other tunics. CONCLUSION These changes may favour atherosclerosis resulting in myocardial ischemia. Ischemic heart disease is the major cause of death and disability among the age group of third to sixth decade of life.

  14. CHRONIC OBSTRUCTIVE PULMONARY DISEASE AND ARTERIAL HYPERTENSION: VASCULAR WALL AS THE TARGET ORGAN IN COMORBID PATIENTS

    Directory of Open Access Journals (Sweden)

    N. A. Karoli

    2017-01-01

    Full Text Available Studies of endothelial dysfunction in patients with respiratory diseases have become relevant in recent years. Perhaps endothelial dysfunction and high arterial stiffness bind bronchopulmonary and cardiovascular diseases.Aim. To reveal features of disturbances of arterial wall vasoregulatory function in patients with chronic obstructive pulmonary disease (COPD in the presence and absence of arterial hypertension (HT.Material and methods. The study included 50 patients with COPD with normal blood pressure (BP and 85 patients with COPD and HT. Control group was presented by 20 practically healthy men comparable in age with COPD patients. Tests with reactive hyperemia (endothelium-dependent dilation and nitroglycerin (endothelium-independent dilation were performed in order to evaluate endothelium function. The number of desquamated endotheliocytes in the blood was determined.Results. In patients with COPD and HT in comparison with COPD patients without HT and healthy individuals more pronounced damages of the vascular wall, endothelium vasoregulatory function disturbances and a tendency to the reduction in endothelium-dependent vasodilation were determined both during COPD exacerbation and remission. These differences were most pronounced during the COPD exacerbation. In patients with COPD and HT in comparison with COPD patients without HT the damage of the vascular wall was more pronounced during the remission and endothelium-dependent dilatation disorder – during the exacerbation. The revealed disorders in patients with COPD and HT were associated with smoking status (r=0.61, p<0.01, severity of bronchial obstruction (r=-0.49, p<0.05, and hypoxemia (r=-0.76, p<0.01. We noted relationships between the parameters of 24-hour BP monitoring and remodeling of the brachial artery (r=0.34, p<0.05, endothelium lesion (r=0.25, p<0.05, and impairment of its vasoregulating function (r=-0.58, p<0.05. At that, the following parameters were important: the

  15. CARDIAC TRANSPLANT REJECTION AND NON-INVASIVE COMON CAROTID ARTERY WALL FUNCTIONAL INDICES

    Directory of Open Access Journals (Sweden)

    A. O. Shevchenko

    2015-01-01

    Full Text Available Allograft rejection would entail an increase in certain blood biomarkers and active substances derived from activated inflammatory cells which could influence entire vascular endothelial function and deteriorate arterial wall stiffness. We propose that carotid wall functional indices measured with non-invasive ultrasound could we valuable markers of the subclinical cardiac allograft rejection. Aim. Our goal was to analyze the clinical utility of functional common carotid wall (CCW variables measured with high-resolution Doppler ultrasound as a non-invasive screening tool for allograft rejection in cardiac transplant patients (pts. Methods. One hundred and seventy one pts included 93 cardiac recipients, 30 dilated cardiomyopathy waiting list pts, and 48 stable coronary artery disease (SCAD pts without decompensated heart failure were included. Along with resistive index (Ri, pulsative index (Pi, and CCW intima-media thickness (IMT, CCW rigidity index (iRIG was estimated using empirical equation. Non-invasive evaluation was performed in cardiac transplant recipients prior the endomyo- cardial biopsy. Results. Neither of Ri, Pi, or CCW IMT were different in studied subgroups. iRIG was signifi- cantly lower in SCAD pts when compared to the dilated cardiomyopathy subgroup. The later had similar values with cardiac transplant recipients without rejection. Antibody-mediated and cellular rejection were found in 22 (23.7% and 17 (18.3% cardiac recipients, respectively. Mean iRIG in pts without rejection was significantly lower in comparison to antibody-mediated rejection and cell-mediated (5514.7 ± 2404.0 vs 11856.1 ± 6643.5 and 16071.9 ± 10029.1 cm/sec2, respectively, p = 0.001. Area under ROC for iRIG was 0.90 ± 0.03 units2. Analysis showed that iRIG values above estimated treshold 7172 cm/sec2 suggested relative risk of any type of rejection 17.7 (95%CI = 6.3–49.9 sensitivity 80.5%, specificity – 81.1%, negative predictive value – 84

  16. Impairment of left ventricular regional wall motion in diabetes mellitus without coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, Ken`ya; Shimonagata, Tuyoshi; Nanto, Shinsuke; Kuroda, Akio; Morozumi, Takakazu; Kamado, Kenji; Nagata, Seiki [Kansai Rosai Hospital, Amagasaki, Hyogo (Japan); Yamasaki, Yoshimitsu

    1996-09-01

    To elucidate the mechanisms of diabetic cardiomyopathy, dual SPECT imaging with thallium-201 (Tl-201) and I-123 beta-methyl-p-iodophenyl pentadecanoic acid (BMIPP), a branched analogue of free fatty acid (FFA), and dipyridamole-infusion Tl-201 scintigraphy were performed in 28 NIDDM patients without coronary artery disease. Twenty eight patients were divided into two groups based on the presence of wall motion abnormalities on cineangiographic left ventriculography (LVG). Nineteen patients with normal wall motion documented on LVG (group A) out of 28 evaluated patients demonstrated normal Tl-201 and I-123 BMIPP uptake in dual SPECT imaging, whereas 9 patients with reduced wall motion (group B) demonstrated reduced I-123 BMIPP uptake when compared with Tl-201 uptake. On dipyridamole-infusion Tl-201 scintigraphy, transient perfusion defects were demonstrated in 4 patients of group B and two patients of group A (p<0.05). These results suggest that small vessel disease and the impairment of myocardial free fatty acid metabolism are etiologic or contributory factors for regional wall motion abnormality in diabetic cardiomyopathy. (author)

  17. Modeling the transport of drugs eluted from stents: physical phenomena driving drug distribution in the arterial wall.

    Science.gov (United States)

    Bozsak, Franz; Chomaz, Jean-Marc; Barakat, Abdul I

    2014-04-01

    Despite recent data that suggest that the overall performance of drug-eluting stents (DES) is superior to that of bare-metal stents, the long-term safety and efficacy of DES remain controversial. The risk of late stent thrombosis associated with the use of DES has also motivated the development of a new and promising treatment option in recent years, namely drug-coated balloons (DCB). Contrary to DES where the drug of choice is typically sirolimus and its derivatives, DCB use paclitaxel since the use of sirolimus does not appear to lead to satisfactory results. Since both sirolimus and paclitaxel are highly lipophilic drugs with similar transport properties, the reason for the success of paclitaxel but not sirolimus in DCB remains unclear. Computational models of the transport of drugs eluted from DES or DCB within the arterial wall promise to enhance our understanding of the performance of these devices. The present study develops a computational model of the transport of the two drugs paclitaxel and sirolimus eluted from DES in the arterial wall. The model takes into account the multilayered structure of the arterial wall and incorporates a reversible binding model to describe drug interactions with the constituents of the arterial wall. The present results demonstrate that the transport of paclitaxel in the arterial wall is dominated by convection while the transport of sirolimus is dominated by the binding process. These marked differences suggest that drug release kinetics of DES should be tailored to the type of drug used.

  18. Coronary artery wall imaging in mice using osmium tetroxide and micro-computed tomography (micro-CT)

    Energy Technology Data Exchange (ETDEWEB)

    Pai, Vinay M.; Kozlowski, Megan; Donahue, Danielle; Miller, Elishiah; Xiao, Xianghui; Chen, Marcus Y.; Yu, Zu-Xi; Connelly, Patricia; Jeffries, Kenneth; Wen, Han (NIH)

    2012-05-10

    The high spatial resolution of micro-computed tomography (micro-CT) is ideal for 3D imaging of coronary arteries in intact mouse heart specimens. Previously, micro-CT of mouse heart specimens utilized intravascular contrast agents that hardened within the vessel lumen and allowed a vascular cast to be made. However, for mouse coronary artery disease models, it is highly desirable to image coronary artery walls and highlight plaques. For this purpose, we describe an ex vivo contrast-enhanced micro-CT imaging technique based on tissue staining with osmium tetroxide (OsO{sub 4}) solution. As a tissue-staining contrast agent, OsO{sub 4} is retained in the vessel wall and surrounding tissue during the fixation process and cleared from the vessel lumens. Its high X-ray attenuation makes the artery wall visible in CT. Additionally, since OsO{sub 4} preferentially binds to lipids, it highlights lipid deposition in the artery wall. We performed micro-CT of heart specimens of 5- to 25-week-old C57BL/6 wild-type mice and 5- to 13-week-old apolipoprotein E knockout (apoE{sup -/-}) mice at 10 {mu}m resolution. The results show that walls of coronary arteries as small as 45 {mu}m in diameter are visible using a table-top micro-CT scanner. Similar image clarity was achieved with 1/2000th the scan time using a synchrotron CT scanner. In 13-week-old apoE mice, lipid-rich plaques are visible in the aorta. Our study shows that the combination of OsO{sub 4} and micro-CT permits the visualization of the coronary artery wall in intact mouse hearts.

  19. New phenotypic aspects of the decidual spiral artery wall during early post-implantation mouse pregnancy

    Energy Technology Data Exchange (ETDEWEB)

    Elia, Artemis; Charalambous, Fotini [Department of Biological Sciences, University of Cyprus, University Campus, P.O. Box 20537, 1678 Nicosia (Cyprus); Georgiades, Pantelis, E-mail: pgeor@ucy.ac.cy [Department of Biological Sciences, University of Cyprus, University Campus, P.O. Box 20537, 1678 Nicosia (Cyprus)

    2011-12-09

    Highlights: Black-Right-Pointing-Pointer Spiral artery (SA) wall remodeling (SAR) is ill-defined and clinically important. Black-Right-Pointing-Pointer SA muscular phenotype prior to and during SAR in mice is underexplored. Black-Right-Pointing-Pointer SA muscular wall consists of contractile and non-contractile components. Black-Right-Pointing-Pointer SA wall non-contractile component may be synthetic smooth muscle. Black-Right-Pointing-Pointer Timing and extent of SA wall contractile component loss is revealed. -- Abstract: During pregnancy the walls of decidual spiral arteries (SAs) undergo clinically important structural modifications crucial for embryo survival/growth and maternal health. However, the mechanisms of SA remodeling (SAR) are poorly understood. Although an important prerequisite to this understanding is knowledge about the phenotype of SA muscular wall prior to and during the beginning of mouse SAR, this remains largely unexplored and was the main aim of this work. Using histological and immunohistochemical techniques, this study shows for the first time that during early mouse gestation, from embryonic day 7.5 (E7.5) to E10.5, the decidual SA muscular coat is not a homogeneous structure, but consists of two concentric layers. The first is a largely one cell-thick sub-endothelial layer of contractile mural cells (positive for {alpha}-smooth muscle actin, calponin and SM22{alpha}) with pericyte characteristics (NG2 positive). The second layer is thicker, and evidence is presented that it may be of the synthetic/proliferative smooth muscle phenotype, based on absence ({alpha}-smooth muscle actin and calponin) or weak (SM22{alpha}) expression of contractile mural cell markers, and presence of synthetic smooth muscle characteristics (expression of non-muscle Myosin heavy chain-IIA and of the cell proliferation marker PCNA). Importantly, immunohistochemistry and morphometrics showed that the contractile mural cell layer although prominent at E7.5-E8

  20. [Efferent innervation of the arteries of human leptomeninx in arterial hypertension].

    Science.gov (United States)

    Chertok, V M; Kotsiuba, A E; Babich, E V

    2009-01-01

    Structure of the efferent nerve plexuses (adrenergic, acetylcholinestherase- and cholinacetyltranspherase-positive, NO-dependent), was studied in the arteries of human leptomeninx with different diameters. Material was obtained from the corpses of the healthy people and of the patients with initial stages of arterial hypertension (AH). It was shown that the concentrations of cholinergic and adrenergic nerve fibers and varicosities in axon terminal part, innervating the arteries with the diameters ranging from 450 till 100 microm, were not significantly different. In these arteries, NO-ergic plexuses were also detected. In patients with AH, regardless the arterial diameters, the significant increase (up to 15-20%) of adrenergic nerve fiber and varicosity concentrations was found. The changes in cholinergic nerve fiber concentration were found to depend on the vessel diameter: the significant decrease of these parameter was observed only in arteries with the diameter of 100-200 microm. No significant changes in nerve plexus concentration was noticed in the arteries with greater or smaller diameter. In NO-ergic neural conductors, the enzyme activity decreased only in the large arteries, and remained almost unchanged in the small vascular branches. The changes in the vasomotor innervation described in AH, are interpreted as a vasomotor innervation dysfunction of the leptomeninx arteries that may result in the hemodynamic disturbances.

  1. Quantitative Evaluation of Left Ventricular Wall Motion in Patient with Coronary Artery Bypass Grafting Using Magnetic Resonance Tagging Technique

    Science.gov (United States)

    Inaba, Tadashi; Nakano, Takahiro; Tsutsumi, Masakazu; Kawasaki, Shingo; Kinosada, Yasutomi; Tokuda, Masataka

    Left ventricular wall motions during systole were investigated from a mechanical perspective by using a magnetic resonance tagging technique. Subjects were 7 patients with coronary artery bypass grafting (CABG). First, by analyzing strain in the left ventricular wall, cardiac contractility was evaluated in the patients with CABG. Next, by calculating displacement in the myocardial wall, paradoxical movements following CABG were quantitatively evaluated. Strain analysis showed local decreases in circumferential strain in 4 of 7 subjects. The results of displacement analysis clarified that following CABG, the degree of radial displacement was small in the septal wall and large in the lateral wall, and circumferential displacement towards the septal wall occurred in the anterior and posterior walls. Since this behavior was seen in both reduced and normal cardiac contractility groups, paradoxical movements in the present patients were not caused by reduced cardiac contractility, but rather by rigid-body motion of the entire heart.

  2. Positive association between increased popliteal artery vessel wall thickness and generalized osteoarthritis: is OA also part of the metabolic syndrome?

    Energy Technology Data Exchange (ETDEWEB)

    Kornaat, Peter R.; Sharma, Ruby; Geest, Rob J. van der; Lamb, Hildo J.; Bloem, Johan L.; Watt, Iain [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Kloppenburg, Margreet [Leiden University Medical Center, Department of Rheumatology, Leiden (Netherlands); Hellio le Graverand, Marie-Pierre [Pfizer Global Research and Development, New London, CT (United States)

    2009-12-15

    The purpose of the study was to determine if a positive association exists between arterial vessel wall thickness and generalized osteoarthritis (OA). Our hypothesis is that generalized OA is another facet of the metabolic syndrome. The medical ethical review board of our institution approved the study. Written informed consent was obtained from each patient prior to the study. Magnetic resonance (MR) images of the knee were obtained in 42 patients who had been diagnosed with generalized OA at multiple joint sites. Another 27 MR images of the knee were obtained from a matched normal (non-OA) reference population. Vessel wall thickness of the popliteal artery was quantitatively measured by dedicated software. Linear regression models were used to investigate the association between vessel wall thickness and generalized OA. Adjustments were made for age, sex, and body mass index (BMI). Confidence intervals (CI) were computed at the 95% level and a significance level of {alpha} = 0.05 was used. Patients in the generalized OA population had a significant higher average vessel wall thickness than persons from the normal reference population (p {<=} {alpha}), even when correction was made for sex, age, and BMI. The average vessel wall thickness of the popliteal artery was 1.09 mm in patients with generalized OA, and 0.96 mm in the matched normal reference population. The association found between increased popliteal artery vessel wall thickness and generalized osteoarthritis suggests that generalized OA might be another facet of the metabolic syndrome. (orig.)

  3. Wall stress of the cervical carotid artery in patients with carotid dissection: a case-control study.

    Science.gov (United States)

    Callaghan, Fraser M; Luechinger, Roger; Kurtcuoglu, Vartan; Sarikaya, Hakan; Poulikakos, Dimos; Baumgartner, Ralf W

    2011-04-01

    Spontaneous internal carotid artery (ICA) dissection (sICAD) results from an intimal tear located around the distal carotid sinus. The mechanisms causing the tear are unknown. This case-control study tested the hypotheses that head movements increase the wall stress in the cervical ICA and that the stress increase is greater in patients with sICAD than in controls. Five patients with unilateral, recanalized, left sICAD and five matched controls were investigated before and after maximal head rotation to the left and neck hyperextension after 45° head rotation to the left. The anatomy of the extracranial carotid arteries was assessed by magnetic resonance imaging and used to create finite element models of the right ICA. Wall stress increased after head movements. Increases above the 80th and 90th percentile were located at the intimal side of the artery wall from 7.4 mm below to 10 mm above the cranial edge of the carotid sinus, i.e., at the same location as histologically confirmed tears in patients with sICAD. Wall stress increase did not differ between patients and controls. The present findings suggest that wall stress increases at the intimal side of the artery wall surrounding the distal edge of the carotid bulb after head movements may be important for the development of carotid dissection. The lack of wall stress difference between the two groups indicates that the carotid arteries of patients with carotid dissection have either distinct functional or anatomical properties or endured unusually heavy wall stresses to initiate dissection.

  4. Portal venous arterialization resulting in increased portal inflow and portal vein wall thickness in rats

    Institute of Scientific and Technical Information of China (English)

    Wen-Gang Li; Yong-Liang Chen; Jing-Xi Chen; Lei Qu; Bin-Dang Xue; Zhi-Hai Peng; Zhi-Qiang Huang

    2008-01-01

    AIM:To explore the influence of portal vein hemodynamic changes after portal venous arterialization(PVA) on peribiliary vascular plexus (PVP)morphological structure and hepatic pathology,and to establish a theoretical basis for the clinical application of PVA.METHODS:Sprague-Dawley rats were randomly divided into control and PVA groups.After PVA,hemodynamic changes of the portal vein and morphological structure of hepatohilar PVP were observed using Doppler ultrasound,liver function tests,ink perfusion transparency management and three-dimensional reconstruction of computer microvisualization,and pathological examination was performed on tissue from the bile duct wall and the liver.RESULTS:After PVA,the cross-sectional area and blood flow of the portal vein were increased,and the increase became more significant over time,in a certain range.If the measure to limit the flow in PVA was not adopted,the high blood flow would lead to dilatation of intrahepatic portal vein and its branches,increase in collagen and fiber degeneration in tunica intima.Except glutamic pyruvic transaminase (GPT),other liver function tests were normal.CONCLUSION:Blood with a certain flow and oxygen content is important for filling the PVP and meeting the oxygen requirement of the bile duct wall.After PVA,It is the anatomic basis to maintain normal morphology of hepatohilar bile duct wall that the blood with high oxygen content and high flow in arterialized portal vein may fill PVP by collateral vessel reflux.A adequate measure to limit blood flow is necessary in PVA.

  5. Reconstruction after Anterior Chest Wall Keloid Resection Using Internal Mammary Artery Perforator Propeller Flaps

    Science.gov (United States)

    Ogawa, Rei; Ono, Shimpei; Akaishi, Satoshi; Dohi, Teruyuki; Iimura, Takeshi; Nakao, Junichi

    2016-01-01

    Background: It is difficult to completely resect huge anterior chest wall keloids and then close the wound directly. We report here our retrospective analysis of our case series of patients with such keloids who underwent reconstruction with internal mammary artery perforator (IMAP) pedicled propeller flaps and then received postoperative high-dose-rate superficial brachytherapy. Methods: All consecutive patients with large/severe keloids on the anterior chest wall who underwent keloid resection followed by reconstruction with IMAP-pedicled propeller flaps and then high-dose-rate superficial brachytherapy in our academic hospital were identified. All cases were followed for >18 months. Donor site position, perforator pedicle, flap size, angle of flap rotation, complications, and recurrence were documented. Results: There were nine men and one woman. The average age was 37.9 years. The average follow-up duration was 28.7 months. The largest flap was 16 × 4 cm. The dominant perforators of the internal mammary artery were located in the sixth (n = 2), seventh (n = 5), eighth (n = 1), and ninth (n = 2) intercostal spaces. Twelve months after surgery, patients reported marked relief from keloid-associated pain and itching, except in two patients who underwent partial keloid resection; their remaining keloids were still troublesome but after conservative therapies, including steroid ointments/plasters, the keloids gradually ameliorated. Eighteen months after surgery, there was no keloid recurrence or new development of keloids on the donor site. Conclusions: IMAP-pedicled propeller flaps transfer skin tension from the anterior chest wall to the abdomen. Our series suggests that this approach combined with radiation therapy can control keloid recurrence.

  6. Assessment of Carotid Arterial Wall Elasticity in Type 2 Diabetes Mellitus Patients with Microalbuminuria by Real-Time Ultrasound Elastography

    Directory of Open Access Journals (Sweden)

    Yu-Hong Zhang

    2012-01-01

    Full Text Available The aim of this study was to evaluate carotid arterial wall elasticity in type 2 diabetes mellitus (T2DM with microalbuminuria by real-time ultrasound elastography. Two hundred and ten T2DM patients were divided into two groups according to levels of urinary albumin excretion (UAE: T2DM without microalbuminuria (T2DM1 group, 120 and T2DM with microalbuminuria (T2DM2 group, 90. The right common carotid arteries were examined by real-time ultrasound elastography. The strain ratio (SR, blood to arterial wall strain ratio was calculated by dividing the strain value of the blood by that of the carotid arterial wall. The correlation between SR and general data was analyzed. The mean SR value ± SD of T2DM2 group was significantly higher than that of T2DM1 group (P<0.05. SR was positively and significantly correlated with UAE, HbA1c, and systolic blood pressure (r=0.456,0.435,0.235, P<0.05 for all. The mean value ± SD of UAE, HbA1c, 2hPG, BMI, and TC of T2DM2 group was significantly higher than that of T2DM1 group (P<0.05 for all. In conclusion, there is an association between microalbuminuria and carotid arterial wall elasticity in T2DM patients.

  7. Influence of constriction, wall tension, smooth muscle activation and cellular deformation on rat resistance artery vasodilator reactivity.

    Science.gov (United States)

    Colton, Ilsley; Mandalà, Maurizio; Morton, Jude; Davidge, Sandra T; Osol, George

    2012-01-01

    This study investigated how vasoconstriction (tone), wall tension, smooth muscle activation, and vascular wall deformation influence resistance artery vasodilator reactivity. Resistance arteries, from two different regional circulations (splanchnic, uterine) and from pregnant and non-pregnant rats, were cannulated and pressurized, or mounted on a wire myograph under isometric conditions prior to being exposed to both endothelium-dependent (acetylcholine, ACh) and -independent (sodium nitroprusside, SNP) vasodilator agonists. A consistent pattern of reduced vasodilator sensitivity was noted as a function of extent of preconstriction for both agonists noted in pressurized arteries. A similar pattern regarding activation was noted in wire-mounted arteries in response to SNP but not ACh. Wall tension proved to be a major determinant of vascular smooth muscle vasodilator reactivity and its normalization reversed this pattern, as more constricted vessels were more sensitive to ACh relaxation without any change in SNP sensitivity, suggesting that endothelial deformation secondary to vasoconstriction augments its vasodilator output. To our knowledge, this is the first study to dissect out the complex interplay between biophysical forces impinging on VSM (pressure, wall tension), the ambient level of tone (vasoconstriction, smooth muscle cell activation), and consequences of cellular (particularly endothelial) deformation secondary to constriction in determining resistance artery vasodilatory reactivity.

  8. Muscle Patterning in Mouse and Human Abdominal Wall Development and Omphalocele Specimens of Humans

    OpenAIRE

    Nichol, Peter F.; Corliss, Robert F.; Yamada, Shigehito; SHIOTA, KOHEI; Saijoh, Yukio

    2012-01-01

    Human omphalocele is a congenital defect of the abdominal wall in which the secondary abdominal wall structures (muscle and connective tissue) in an area centered around the umbilicus are replaced by a translucent membranous layer of tissue. Histological examination of omphalocele development and moreover the staging of normal human abdominal wall development has never been described. We hypothesized that omphalocele is the result of an arrest in the secondary abdominal wall development and p...

  9. Integration of a capacitive pressure sensing system into the outer catheter wall for coronary artery FFR measurements

    Science.gov (United States)

    Stam, Frank; Kuisma, Heikki; Gao, Feng; Saarilahti, Jaakko; Gomes Martins, David; Kärkkäinen, Anu; Marrinan, Brendan; Pintal, Sebastian

    2017-05-01

    The deadliest disease in the world is coronary artery disease (CAD), which is related to a narrowing (stenosis) of blood vessels due to fatty deposits, plaque, on the arterial walls. The level of stenosis in the coronary arteries can be assessed by Fractional Flow Reserve (FFR) measurements. This involves determining the ratio between the maximum achievable blood flow in a diseased coronary artery and the theoretical maximum flow in a normal coronary artery. The blood flow is represented by a pressure drop, thus a pressure wire or pressure sensor integrated in a catheter can be used to calculate the ratio between the coronary pressure distal to the stenosis and the normal coronary pressure. A 2 Fr (0.67mm) outer diameter catheter was used, which required a high level of microelectronics miniaturisation to fit a pressure sensing system into the outer wall. The catheter has an eccentric guidewire lumen with a diameter of 0.43mm, which implies that the thickest catheter wall section provides less than 210 microns height for flex assembly integration consisting of two dies, a capacitive MEMS pressure sensor and an ASIC. In order to achieve this a very thin circuit flex was used, and the two chips were thinned down to 75 microns and flip chip mounted face down on the flex. Many challenges were involved in obtaining a flex layout that could wrap into a small tube without getting the dies damaged, while still maintaining enough flexibility for the catheter to navigate the arterial system.

  10. Energy harvesting from arterial blood pressure for powering embedded micro sensors in human brain

    Science.gov (United States)

    Nanda, Aditya; Karami, M. Amin

    2017-03-01

    This manuscript investigates energy harvesting from arterial blood pressure via the piezoelectric effect for the purpose of powering embedded micro-sensors in the human brain. One of the major hurdles in recording and measuring electrical data in the human nervous system is the lack of implantable and long term interfaces that record neural activity for extended periods of time. Recently, some authors have proposed micro sensors implanted deep in the brain that measure local electrical and physiological data which are then communicated to an external interrogator. This paper proposes a way of powering such interfaces. The geometry of the proposed harvester consists of a piezoelectric, circular, curved bimorph that fits into the blood vessel (specifically, the Carotid artery) and undergoes bending motion because of blood pressure variation. In addition, the harvester thickness is constrained such that it does not modify arterial wall dynamics. This transforms the problem into a known strain problem and the integral form of Gauss's law is used to obtain an equation relating arterial wall motion to the induced voltage. The theoretical model is validated by means of a Multiphysics 3D-FEA simulation comparing the harvested power at different load resistances. The peak harvested power achieved for the Carotid artery (proximal to Brain), with PZT-5H, was 11.7 μW. The peak power for the Aorta was 203.4 μW. Further, the variation of harvested power with variation in the harvester width and thickness, arterial contractility, and pulse rate is investigated. Moreover, potential application of the harvester as a chronic, implantable and real-time Blood pressure sensor is considered. Energy harvested via this mechanism will also have applications in long-term, implantable Brain Micro-stimulation.

  11. Bioresorbable microporous stents deliver recombinant adenovirus gene transfer vectors to the arterial wall.

    Science.gov (United States)

    Ye, Y W; Landau, C; Willard, J E; Rajasubramanian, G; Moskowitz, A; Aziz, S; Meidell, R S; Eberhart, R C

    1998-01-01

    The use of intravascular stents as an adjunct for percutaneous transluminal revascularization is limited by two principal factors, acute thrombosis and neointimal proliferation, resulting in restenosis. To overcome these limitations, we have investigated the potential of microporous bioresorbable polymer stents formed from poly(L-lactic acid) (PLLA)/poly(epsilon-caprolactone) (PCL) blends to function both to provide mechanical support and as reservoirs for local delivery of therapeutic molecules and particles to the vessel wall. Tubular PLLA/PCL stents were fabricated by the flotation-precipitation method, and helical stents were produced by a casting/winding technique. Hybrid structures in which a tubular sheath is deposited on a helical skeleton were also generated. Using a two-stage solvent swelling technique, polyethylene oxide has been incorporated into these stents to improve hydrophilicity and water uptake, and to facilitate the ability of these devices to function as drug carriers. Stents modified in this manner retain axial and radial mechanical strength sufficient to stabilize the vessel wall against elastic recoil caused by vasoconstrictive and mechanical forces. Because of the potential of direct gene transfer into the vessel wall to ameliorate thrombosis and neointimal proliferation, we have investigated the capacity of these polymer stents to function in the delivery of recombinant adenovirus vectors to the vessel wall. In vitro, virus stock was observed to readily absorb into, and elute from these devices in an infectious form, with suitable kinetics. Successful gene transfer and expression has been demonstrated following implantation of polymer stents impregnated with a recombinant adenovirus carrying a nuclear-localizing betaGal reporter gene into rabbit carotid arteries. These studies suggest that surface-modified polymer stents may ultimately be useful adjunctive devices for both mechanical support and gene transfer during percutaneous

  12. Unsteady Integrodifferential Equation of Fluid-Structure Interaction in Constricted Collapsible Tube Model of Diseased Human Coronary Artery

    Directory of Open Access Journals (Sweden)

    Eric Velaski Tuema

    2012-01-01

    Full Text Available Unsteady flow in a collapsible tube is analyzed to simulate a diseased human coronary artery. The novelty of the approach is that the set of equations governing the fluid-structure interaction is reduced to a single integrodifferential equation in the transient state. The equation is then solved using the finite difference method to obtain the flow characteristics and compliant wall behavior. Three control parameters are investigated, namely, Reynolds number, inlet transmural pressure, and the wall thickness. The predicted wall deflection is quite large at low Reynolds numbers, suggesting possible approach to breakdown in equilibrium. The transmural pressure increases with wall deflection and bulges appear at the ends of the membrane indicating critical stage of stability, consistent with previous studies. Increase in wall thickness reduces the wall deflection and ultimately results in its collapse which may indicate another breakdown in equilibrium. An increase in internal pressure is required to maintain membrane stability.

  13. Association between proximal internal carotid artery steno-occlusive disease and diffuse wall thickening in its petrous segment: a magnetic resonance vessel wall imaging study

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiaoyi; Li, Dongye [Capital Medical University and Beijing Institute for Brain Disorders, Center for Brain Disorders Research, Beijing (China); Tsinghua University School of Medicine, Center for Biomedical Imaging Research, Department of Biomedical Engineering, Beijing (China); Zhao, Huilin [Shanghai Jiao Tong University, Department of Radiology, Renji Hospital, School of Medicine, Shanghai (China); Chen, Zhensen; Qiao, Huiyu; He, Le; Li, Rui [Tsinghua University School of Medicine, Center for Biomedical Imaging Research, Department of Biomedical Engineering, Beijing (China); Cui, Yuanyuan [PLA General Hospital, Department of Radiology, Beijing (China); Zhou, Zechen [Philips Research China, Healthcare Department, Beijing (China); Yuan, Chun [Tsinghua University School of Medicine, Center for Biomedical Imaging Research, Department of Biomedical Engineering, Beijing (China); University of Washington, Department of Radiology, Seattle, WA (United States); Zhao, Xihai [Tsinghua University School of Medicine, Center for Biomedical Imaging Research, Department of Biomedical Engineering, Beijing (China); Beijing Institute for Brain Disorders, Center for Stroke, Beijing (China)

    2017-05-15

    Significant stenosis or occlusion in carotid arteries may lead to diffuse wall thickening (DWT) in the arterial wall of downstream. This study aimed to investigate the correlation between proximal internal carotid artery (ICA) steno-occlusive disease and DWT in ipsilateral petrous ICA. Symptomatic patients with atherosclerotic stenosis (>0%) in proximal ICA were recruited and underwent carotid MR vessel wall imaging. The 3D motion sensitized-driven equilibrium prepared rapid gradient-echo (3D-MERGE) was acquired for characterizing the wall thickness and longitudinal extent of the lesions in petrous ICA and the distance from proximal lesion to the petrous ICA. The stenosis degree in proximal ICA was measured on the time-of-flight (TOF) images. In total, 166 carotid arteries from 125 patients (mean age 61.0 ± 10.5 years, 99 males) were eligible for final analysis and 64 showed DWT in petrous ICAs. The prevalence of severe DWT in petrous ICA was 1.4%, 5.3%, 5.9%, and 80.4% in ipsilateral proximal ICAs with stenosis category of 1%-49%, 50%-69%, 70%-99%, and total occlusion, respectively. Proximal ICA stenosis was significantly correlated with the wall thickness in petrous ICA (r = 0.767, P < 0.001). Logistic regression analysis showed that proximal ICA stenosis was independently associated with DWT in ipsilateral petrous ICA (odds ratio (OR) = 2.459, 95% confidence interval (CI) 1.896-3.189, P < 0.001). Proximal ICA steno-occlusive disease is independently associated with DWT in ipsilateral petrous ICA. (orig.)

  14. X-ray micro computed tomography for the visualization of an atherosclerotic human coronary artery

    Science.gov (United States)

    Matviykiv, Sofiya; Buscema, Marzia; Deyhle, Hans; Pfohl, Thomas; Zumbuehl, Andreas; Saxer, Till; Müller, Bert

    2017-06-01

    Atherosclerosis refers to narrowing or blocking of blood vessels that can lead to a heart attack, chest pain or stroke. Constricted segments of diseased arteries exhibit considerably increased wall shear stress, compared to the healthy ones. One of the possibilities to improve patient’s treatment is the application of nano-therapeutic approaches, based on shear stress sensitive nano-containers. In order to tailor the chemical composition and subsequent physical properties of such liposomes, one has to know precisely the morphology of critically stenosed arteries at micrometre resolution. It is often obtained by means of histology, which has the drawback of offering only two-dimensional information. Additionally, it requires the artery to be decalcified before sectioning, which might lead to deformations within the tissue. Micro computed tomography (μCT) enables the three-dimensional (3D) visualization of soft and hard tissues at micrometre level. μCT allows lumen segmentation that is crucial for subsequent flow simulation analysis. In this communication, tomographic images of a human coronary artery before and after decalcification are qualitatively and quantitatively compared. We analyse the cross section of the diseased human coronary artery before and after decalcification, and calculate the lumen area of both samples.

  15. Ultrasonic Measurement of Transient Change in Stress-Strain Property of Radial Arterial Wall Caused by Endothelium-Dependent Vasodilation

    Science.gov (United States)

    Ikeshita, Kazuki; Hasegawa, Hideyuki; Kanai, Hiroshi

    2008-05-01

    The endothelial dysfunction is considered to be an initial step of atherosclerosis. Additionally, it was reported that the smooth muscle, which constructs the media of the artery, changes its characteristics owing to atherosclerosis. Therefore, it is essential to develop a method for assessing the regional endothelial function and mechanical property of the arterial wall. There is a conventional technique of measuring the transient change in the diameter of the brachial artery caused by flow-mediated dilation (FMD) after the release of avascularization. For more sensitive and regional evaluation, we developed a method of measuring the change in the elasticity of the radial artery due to FMD. In this study, the transient change in the mechanical property of the arterial wall was further revealed by measuring the stress-strain relationship during each heartbeat. The minute change in the thickness (strain) of the radial arterial wall during a cardiac cycle was measured by the phased tracking method, together with the waveform of blood pressure which was continuously measured with a sphygmometer at the radial artery. The transient change in stress-strain relationship during a cardiac cycle was obtained from the measured changes in wall thickness and blood pressure to show the transient change in instantaneous viscoelasticity. From the in vivo experimental results, the stress-strain relationship shows the hysteresis loop. The slope of the loop decreased owing to FMD, which shows that the elastic modulus decreased, and the increasing area of the loop depends on the ratio of the loss modulus (depends on viscosity) to the elastic modulus when the Voigt model is assumed. These results show a potential of the proposed method for the thorough analysis of the transient change in viscoelasticity due to FMD.

  16. Development of the ventral body wall in the human embryo.

    Science.gov (United States)

    Mekonen, Hayelom K; Hikspoors, Jill P J M; Mommen, Greet; Köhler, S Eleonore; Lamers, Wouter H

    2015-11-01

    Migratory failure of somitic cells is the commonest explanation for ventral body wall defects. However, the embryo increases ~ 25-fold in volume in the period that the ventral body wall forms, so that differential growth may, instead, account for the observed changes in topography. Human embryos between 4 and 10 weeks of development were studied, using amira reconstruction and cinema 4D remodeling software for visualization. Initially, vertebrae and ribs had formed medially, and primordia of sternum and hypaxial flank muscle primordium laterally in the body wall at Carnegie Stage (CS)15 (5.5 weeks). The next week, ribs and muscle primordium expanded in ventrolateral direction only. At CS18 (6.5 weeks), separate intercostal and abdominal wall muscles differentiated, and ribs, sterna, and muscles began to expand ventromedially and caudally, with the bilateral sternal bars fusing in the midline after CS20 (7 weeks) and the rectus muscles reaching the umbilicus at CS23 (8 weeks). The near-constant absolute distance between both rectus muscles and approximately fivefold decline of this distance relative to body circumference between 6 and 10 weeks identified dorsoventral growth in the dorsal body wall as determinant of the 'closure' of the ventral body wall. Concomitant with the straightening of the embryonic body axis after the 6th week, the abdominal muscles expanded ventrally and caudally to form the infraumbilical body wall. Our data, therefore, show that the ventral body wall is formed by differential dorsoventral growth in the dorsal part of the body.

  17. Fractional-order viscoelasticity applied to describe uniaxial stress relaxation of human arteries

    Energy Technology Data Exchange (ETDEWEB)

    Craiem, Damian; Armentano, Ricardo L [Facultad de IngenierIa, Ciencias Exactas y Naturales, Favaloro University, Buenos Aires (Argentina); Rojo, Francisco J; Atienza, Jose Miguel; Guinea, Gustavo V [Departamento de Ciencia de Materiales, Universidad Politecnica de Madrid, Madrid (Spain)], E-mail: dcraiem@favaloro.edu.ar

    2008-09-07

    Viscoelastic models can be used to better understand arterial wall mechanics in physiological and pathological conditions. The arterial wall reveals very slow time-dependent decays in uniaxial stress-relaxation experiments, coherent with weak power-law functions. Quasi-linear viscoelastic (QLV) theory was successfully applied to modeling such responses, but an accurate estimation of the reduced relaxation function parameters can be very difficult. In this work, an alternative relaxation function based on fractional calculus theory is proposed to describe stress relaxation experiments in strips cut from healthy human aortas. Stress relaxation (1 h) was registered at three incremental stress levels. The novel relaxation function with three parameters was integrated into the QLV theory to fit experimental data. It was based in a modified Voigt model, including a fractional element of order {alpha}, called spring-pot. The stress-relaxation prediction was accurate and fast. Sensitivity plots for each parameter presented a minimum near their optimal values. Least-squares errors remained below 2%. Values of order {alpha} = 0.1-0.3 confirmed a predominant elastic behavior. The other two parameters of the model can be associated to elastic and viscous constants that explain the time course of the observed relaxation function. The fractional-order model integrated into the QLV theory proved to capture the essential features of the arterial wall mechanical response.

  18. Innervation of the human middle meningeal artery

    DEFF Research Database (Denmark)

    Edvinsson, L; Gulbenkian, S; Barroso, C P

    1998-01-01

    in arteries without endothelium, while the responses to norepinephrine, NPY, VIP, PHM, and CGRP were not changed by endothelium removal. Blockade experiments showed that the vasomotor responses to norepinephrine were blocked by prazosin, to NPY by BIBP 3226, acetylcholine by atropin, substance P by RP 67580...

  19. Basic fibroblast growth factor gene transfection in repair of internal carotid artery aneurysm wall

    Institute of Scientific and Technical Information of China (English)

    Lei Jiao; Ming Jiang; Jinghai Fang; Yinsheng Deng; Zejun Chen; Min Wu

    2012-01-01

    Surgery or interventional therapy has some risks in the treatment of cerebral aneurysm. We established an internal carotid artery aneurysm model by dripping elastase in the crotch of the right internal and external carotid arteries of New Zealand rabbits. Following model induction, lentivirus carrying basic fibroblast growth factor was injected through the ear vein. We found that the longer the action time of the lentivirus, the smaller the aneurysm volume. Moreover, platelet-derived growth factor expression in the aneurysm increased, but smooth muscle 22 alpha and hypertension-related gene 1 mRNA expression decreased. At 1, 2, 3, and 4 weeks following model establishment, following 1 week of injection of lentivirus carrying basic fibroblast growth factor, the later the intervention time, the more severe the blood vessel damage, and the bigger the aneurysm volume, the lower the smooth muscle 22 alpha and hypertension-related gene 1 mRNA expression. Simultaneously, platelet-derived growth factor expression decreased. These data suggest that recombinant lentivirus carrying basic fibroblast growth factor can repair damaged cells in the aneurysmal wall and inhibit aneurysm dynamic growth, and that the effect is dependent on therapeutic duration.

  20. Arteries of the anterior wall of the maxilla in sinus lift surgery.

    Science.gov (United States)

    Rysz, M; Ciszek, B; Rogowska, M; Krajewski, R

    2014-09-01

    Knowledge of the anatomical course of the anterior maxillary wall and alveolar process arteries is essential for sinus lift procedures. The aim of this study was to analyse the localization of anastomoses between the infraorbital and posterior superior alveolar artery on 101 computed tomography (CT) scans of maxillary sinuses (patients aged 18-70 years). The distance from the anastomosis to the bone point was measured on CT scans for each tooth location; for edentulous patients measurements were made to the lower edge of the alveolar process, and for dentate patients to the neck of the tooth. Measurements were done independently by two observers. The anastomosis analysed was identified on 50% of CT scans. The distance to the anastomosis was longest above the premolar (20.4 mm from tooth cervical line) and shortest above the first molar (15.9 mm to the edge of the alveolar process). The anastomosis can be localized on a CT scan for exact positioning of the antrotomy in 50% of patients. For the remaining patients, the anatomical information provided in this study can be used to reduce the risk of damage to the anastomosis. This study provides information on the distance from the anastomosis to the neck of preserved teeth in partially edentulous patients, which can be used as a reference point during sinus lift procedures. Copyright © 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  1. Impact of blood rheology on wall shear stress in a model of the middle cerebral artery

    Science.gov (United States)

    Bernabeu, Miguel O.; Nash, Rupert W.; Groen, Derek; Carver, Hywel B.; Hetherington, James; Krüger, Timm; Coveney, Peter V.

    2013-01-01

    Perturbations to the homeostatic distribution of mechanical forces exerted by blood on the endothelial layer have been correlated with vascular pathologies, including intracranial aneurysms and atherosclerosis. Recent computational work suggests that, in order to correctly characterize such forces, the shear-thinning properties of blood must be taken into account. To the best of our knowledge, these findings have never been compared against experimentally observed pathological thresholds. In this work, we apply the three-band diagram (TBD) analysis due to Gizzi et al. (Gizzi et al. 2011 Three-band decomposition analysis of wall shear stress in pulsatile flows. Phys. Rev. E 83, 031902. (doi:10.1103/PhysRevE.83.031902)) to assess the impact of the choice of blood rheology model on a computational model of the right middle cerebral artery. Our results show that, in the model under study, the differences between the wall shear stress predicted by a Newtonian model and the well-known Carreau–Yasuda generalized Newtonian model are only significant if the vascular pathology under study is associated with a pathological threshold in the range 0.94–1.56 Pa, where the results of the TBD analysis of the rheology models considered differs. Otherwise, we observe no significant differences. PMID:24427534

  2. A Computational Model to Assess Poststenting Wall Stresses Dependence on Plaque Structure and Stenosis Severity in Coronary Artery

    Directory of Open Access Journals (Sweden)

    Zuned Hajiali

    2014-01-01

    Full Text Available The current study presents computational models to investigate the poststenting hemodynamic stresses and internal stresses over/within the diseased walls of coronary arteries which are in different states of atherosclerotic plaque. The finite element method is applied to build the axisymmetric models which include the plaque, arterial wall, and stent struts. The study takes into account the mechanical effects of the opening pressure and its association with the plaque severity and the morphology. The wall shear stresses and the von Mises stresses within the stented coronary arteries show their strong dependence on the plaque structure, particularly the fibrous cap thickness. Higher stresses occur in severely stenosed coronaries with a thinner fibrous cap. Large stress concentrations around the stent struts cause injury or damage to the vessel wall which is linked to the mechanism of restenosis. The in-stent restenosis rate is also highly dependent on the opening pressure, to the extent that stenosed artery is expanded, and geometry of the stent struts. The present study demonstrates, for the first time, that the restenosis is to be viewed as a consequence of biomechanical design of a stent repeating unit, the opening pressure, and the severity and morphology of the plaque.

  3. Data density curves of B-mode ultrasound arterial wall thickness measurements in unaffected control and at-risk populations

    NARCIS (Netherlands)

    de Groot, E; Hovingh, GK; Zwinderman, AH; Wiegman, A; Smit, AJ; Kastelein, JJP

    2005-01-01

    Aim. Atherosclerosis is a slow disease process of arterial walls with onset decades prior to its clinical manifestations. Lifelong follow-up data may help to identify and understand the pathophysiology of this process. These longitudinal data are scarce. Using a standardized imaging and image analys

  4. A Combination of Constitutive Damage Model and Artificial Neural Networks to Characterize the Mechanical Properties of the Healthy and Atherosclerotic Human Coronary Arteries.

    Science.gov (United States)

    Karimi, Alireza; Rahmati, Seyed Mohammadali; Sera, Toshihiro; Kudo, Susumu; Navidbakhsh, Mahdi

    2017-02-02

    It has been indicated that the content and structure of the elastin and collagen of the arterial wall can subject to a significant alteration due to the atherosclerosis. Consequently, a high tissue stiffness, stress, and even damage/rupture are triggered in the arterial wall. Although many studies so far have been conducted to quantify the mechanical properties of the coronary arteries, none of them consider the role of collagen damage of the healthy and atherosclerotic human coronary arterial walls. Recently, a fiber family-based constitutive equation was proposed to capture the anisotropic mechanical response of the healthy and atherosclerotic human coronary arteries via both the histostructural and uniaxial data. In this study, experimental mechanical measurements along with histological data of the healthy and atherosclerotic arterial walls were employed to determine the constitutive damage parameters and remodeling of the collagen fibers. To do this, the preconditioned arterial tissues were excised from human cadavers within 5-h postmortem, and the mean angle of their collagen fibers was precisely determined. Thereafter, a group of quasistatic axial and circumferential loadings were applied to the arterial walls, and the constrained nonlinear minimization method was employed to identify the arterial parameters according to the axial and circumferential extension data. The remodeling of the collagen fibers during the tensile test was also predicted via Artificial Neural Networks algorithm. Regardless of loading direction, the results presented a noteworthy load-bearing capability and stiffness of the atherosclerotic arteries compared to the healthy ones (P < 0.005). Theoretical fiber angles were found to be consistent with the experimental histological data with less than 2 and 5° difference for the healthy and atherosclerotic arterial walls, respectively. The pseudoelastic damage model data were also compared with that of the experimental data, and

  5. Variable-viscosity thermal hemodynamic slip flow conveying nanoparticles through a permeable-walled composite stenosed artery

    Science.gov (United States)

    Akbar, Noreen Sher; Tripathi, Dharmendra; Bég, O. Anwar

    2017-07-01

    This paper presents a mathematical model for simulating viscous, incompressible, steady-state blood flow containing copper nanoparticles and coupled heat transfer through a composite stenosed artery with permeable walls. Wall slip hydrodynamic and also thermal buoyancy effects are included. The artery is simulated as an isotropic elastic tube, following Joshi et al. (2009), and a variable viscosity formulation is employed for the flowing blood. The equations governing the transport phenomena are non-dimensionalized and the resulting boundary value problem is solved analytically in the steady state subject to physically appropriate boundary conditions. Numerical computations are conducted to quantify the effects of relevant hemodynamic, thermophysical and nanoscale parameters emerging in the model on velocity and temperature profiles, wall shear stress, impedance resistance and also streamline distributions. The model may be applicable to drug fate transport modeling with nanoparticle agents and also to the optimized design of nanoscale medical devices for diagnosing stenotic diseases in circulatory systems.

  6. Effects of arterial blood flow on walls of the abdominal aorta: distributions of wall shear stress and oscillatory shear index determined by phase-contrast magnetic resonance imaging.

    Science.gov (United States)

    Sughimoto, Koichi; Shimamura, Yoshiaki; Tezuka, Chie; Tsubota, Ken'ichi; Liu, Hao; Okumura, Kenichiro; Masuda, Yoshitada; Haneishi, Hideaki

    2016-07-01

    Although abdominal aortic aneurysms (AAAs) occur mostly inferior to the renal artery, the mechanism of the development of AAA in relation to its specific location is not yet clearly understood. The objective of this study was to evaluate the hypothesis that even healthy volunteers may manifest specific flow characteristics of blood flow and alter wall shear or oscillatory shear stress in the areas where AAAs commonly develop. Eight healthy male volunteers were enrolled in this prospective study, aged from 24 to 27. Phase-contrast magnetic resonance imaging (MRI) was performed with electrocardiographic triggering. Flow-sensitive four-dimensional MR imaging of the abdominal aorta, with three-directional velocity encoding, including simple morphological image acquisition, was performed. Information on specific locations on the aortic wall was applied to the flow encodes to calculate wall shear stress (WSS) and oscillatory shear index (OSI). While time-framed WSS showed the highest peak of 1.14 ± 0.25 Pa in the juxtaposition of the renal artery, the WSS plateaued to 0.61 Pa at the anterior wall of the abdominal aorta. The OSI peaked distal to the renal arteries at the posterior wall of the abdominal aorta of 0.249 ± 0.148, and was constantly elevated in the whole abdominal aorta at more than 0.14. All subjects were found to have elevated OSI in regions where AAAs commonly occur. These findings indicate that areas of constant peaked oscillatory shear stress in the infra-renal aorta may be one of the factors that lead to morphological changes over time, even in healthy individuals.

  7. Human uterine wall tension trajectories and the onset of parturition.

    Directory of Open Access Journals (Sweden)

    Peter Sokolowski

    Full Text Available Uterine wall tension is thought to be an important determinant of the onset of labor in pregnant women. We characterize human uterine wall tension using ultrasound from the second trimester of pregnancy until parturition and compare preterm, term and twin pregnancies. A total of 320 pregnant women were followed from first antenatal visit to delivery during the period 2000-2004 at the John Hunter Hospital, NSW, Australia. The uterine wall thickness, length, anterior-posterior diameter and transverse diameter were determined by serial ultrasounds. Subjects were divided into three groups: women with singleton pregnancies and spontaneous labor onset, either preterm or term and women with twin pregnancies. Intrauterine pressure results from the literature were combined with our data to form trajectories for uterine wall thickness, volume and tension for each woman using the prolate ellipsoid method and the groups were compared at 20, 25 and 30 weeks gestation. Uterine wall tension followed an exponential curve, with results increasing throughout pregnancy with the site of maximum tension on the anterior wall. For those delivering preterm, uterine wall thickness was increased P < 0.05 compared with term. For twin pregnancies intrauterine volume was increased compared to singletons (P < 0.001, but wall thickness was not. There was no evidence for increased tension in those delivering preterm or those with twin gestations. These data are not consistent with a role for high uterine wall tension as a causal factor in preterm spontaneous labor in singleton or twin gestations. It seems likely that hormonal differences in multiple gestations are responsible for increased rates of preterm birth in this group rather than increased tension.

  8. Human uterine wall tension trajectories and the onset of parturition.

    Science.gov (United States)

    Sokolowski, Peter; Saison, Francis; Giles, Warwick; McGrath, Shaun; Smith, David; Smith, Julia; Smith, Roger

    2010-06-23

    Uterine wall tension is thought to be an important determinant of the onset of labor in pregnant women. We characterize human uterine wall tension using ultrasound from the second trimester of pregnancy until parturition and compare preterm, term and twin pregnancies. A total of 320 pregnant women were followed from first antenatal visit to delivery during the period 2000-2004 at the John Hunter Hospital, NSW, Australia. The uterine wall thickness, length, anterior-posterior diameter and transverse diameter were determined by serial ultrasounds. Subjects were divided into three groups: women with singleton pregnancies and spontaneous labor onset, either preterm or term and women with twin pregnancies. Intrauterine pressure results from the literature were combined with our data to form trajectories for uterine wall thickness, volume and tension for each woman using the prolate ellipsoid method and the groups were compared at 20, 25 and 30 weeks gestation. Uterine wall tension followed an exponential curve, with results increasing throughout pregnancy with the site of maximum tension on the anterior wall. For those delivering preterm, uterine wall thickness was increased P < 0.05 compared with term. For twin pregnancies intrauterine volume was increased compared to singletons (P < 0.001), but wall thickness was not. There was no evidence for increased tension in those delivering preterm or those with twin gestations. These data are not consistent with a role for high uterine wall tension as a causal factor in preterm spontaneous labor in singleton or twin gestations. It seems likely that hormonal differences in multiple gestations are responsible for increased rates of preterm birth in this group rather than increased tension.

  9. Placental growth factor is a potent vasodilator of rat and human resistance arteries.

    Science.gov (United States)

    Osol, George; Celia, Gerard; Gokina, Natalia; Barron, Carolyn; Chien, Edward; Mandala, Maurizio; Luksha, Leonid; Kublickiene, Karolina

    2008-03-01

    The objectives of this study were to determine whether placental growth factor (PlGF) exerts a vasodilatory effect on rat uterine vessels (arcuate arteries and veins) and to examine regional differences in reactivity by comparing these responses to those of comparably sized mesenteric vessels. We also sought to examine and compare its effects on human uterine and subcutaneous vessels. All vessels were studied in vitro, under pressurized (rat) or isometric wire-mounted (human) conditions, and exposed to a range of PlGF concentrations. Inhibitors of nitric oxide and prostaglandin synthesis were included in an effort to understand the causal mechanism(s). In rat uterine arteries, the effects of receptor inhibition and activation using selective ligands for VEGFR-1 (PlGF) vs. VEGFR-2 (VEGF-E) were determined, and real-time RT-PCR was performed to evaluate the effect of pregnancy on relative abundance of VEGFR-1 and VEGFR-2 message in the vascular wall. PlGF was a potent vasodilator of all vessels studied, with greatest sensitivity observed in rat uterine arteries. Pregnancy significantly augmented dilator sensitivity to PlGF, and this effect was associated with selective upregulation of VEGFR-1 message in the pregnant state. The contribution of nitric oxide was appreciable in rat and human uterine arteries, with lesser effects in rat uterine veins and mesenteric arteries, and with no observable effect in human subcutaneous vessels. Based on these results, we conclude that PlGF is a potent vasodilator of several vessel types in both humans and rats. Its potency and mechanism vary with physiological state and vessel location and are mediated solely by the VEGFR-1 receptor subtype. Gestational changes in the uterine circulation suggest that this factor may play a role in modulating uterine vascular remodeling and blood flow during the pregnant state.

  10. PLACENTAL GROWTH FACTOR (PlGF) IS A POTENT VASODILATOR OF RAT AND HUMAN RESISTANCE ARTERIES

    Science.gov (United States)

    Osol, George; Celia, Gerard; Gokina, Natalia; Barron, Carolyn; Chien, Edward; Mandala, Maurizio; Luksha, Leonid; Kublickiene, Karolina

    2010-01-01

    The objectives of this study were to determine whether PlGF exerts a vasodilatory effect on rat uterine vessels (arcuate arteries and veins) and to examine regional differences in reactivity by comparing these responses to those of comparably-sized mesenteric vessels. We also sought to examine and compare its effects on human uterine and subcutaneous vessels. All vessels were studied in vitro, under pressurized (rat) or isometric wire-mounted (human) conditions, and exposed to a range of PlGF concentrations. Inhibitors of nitric oxide and prostaglandin synthesis were included in an effort to understand the causal mechanism(s). In rat uterine arteries, the effects of receptor inhibition and activation using selective ligands for VEGFR-1 (PlGF) vs. VEGFR-2 (VEGF-E) were determined, and real-time RT-PCR was performed to evaluate the effect of pregnancy on relative abundance of VEGFR-1 and VEGFR-2 message in the vascular wall. PlGF was a potent vasodilator of all vessels studied, with greatest sensitivity observed in rat uterine arteries. Pregnancy significantly augmented dilator sensitivity to PlGF, and this effect was associated with selective upregulation of VEGFR-1 message in the pregnant state. The contribution of nitric oxide was appreciable in rat and human uterine arteries, with lesser effects in rat uterine veins and mesenteric arteries, and with no observable effect in human subcutaneous vessels. Based on these results, we conclude that PlGF is a potent vasodilator of several vessel types in both humans and rats. Its potency and mechanism varies with physiological state and vessel location, and is mediated solely by the VEGFR-1 receptor subtype. Gestational changes in the uterine circulation suggest that this factor may play a role in modulating uterine vascular remodeling and blood flow during the pregnant state. PMID:18192215

  11. Mathematical modeling of coupled drug and drug-encapsulated nanoparticle transport in patient-specific coronary artery walls

    KAUST Repository

    Hossain, Shaolie S.

    2011-08-20

    The majority of heart attacks occur when there is a sudden rupture of atherosclerotic plaque, exposing prothrombotic emboli to coronary blood flow, forming clots that can cause blockages of the arterial lumen. Diseased arteries can be treated with drugs delivered locally to vulnerable plaques. The objective of this work was to develop a computational tool-set to support the design and analysis of a catheter-based nanoparticulate drug delivery system to treat vulnerable plaques and diffuse atherosclerosis. A threedimensional mathematical model of coupled mass transport of drug and drug-encapsulated nanoparticles was developed and solved numerically utilizing isogeometric finite element analysis. Simulations were run on a patient-specific multilayered coronary artery wall segment with a vulnerable plaque and the effect of artery and plaque inhomogeneity was analyzed. The method captured trends observed in local drug delivery and demonstrated potential for optimizing drug design parameters, including delivery location, nanoparticle surface properties, and drug release rate. © Springer-Verlag 2011.

  12. Mathematical modeling of coupled drug and drug-encapsulated nanoparticle transport in patient-specific coronary artery walls

    Science.gov (United States)

    Hossain, Shaolie S.; Hossainy, Syed F. A.; Bazilevs, Yuri; Calo, Victor M.; Hughes, Thomas J. R.

    2012-02-01

    The majority of heart attacks occur when there is a sudden rupture of atherosclerotic plaque, exposing prothrombotic emboli to coronary blood flow, forming clots that can cause blockages of the arterial lumen. Diseased arteries can be treated with drugs delivered locally to vulnerable plaques. The objective of this work was to develop a computational tool-set to support the design and analysis of a catheter-based nanoparticulate drug delivery system to treat vulnerable plaques and diffuse atherosclerosis. A three-dimensional mathematical model of coupled mass transport of drug and drug-encapsulated nanoparticles was developed and solved numerically utilizing isogeometric finite element analysis. Simulations were run on a patient-specific multilayered coronary artery wall segment with a vulnerable plaque and the effect of artery and plaque inhomogeneity was analyzed. The method captured trends observed in local drug delivery and demonstrated potential for optimizing drug design parameters, including delivery location, nanoparticle surface properties, and drug release rate.

  13. Hemorheological abnormalities in human arterial hypertension

    Science.gov (United States)

    Lo Presti, Rosalia; Hopps, Eugenia; Caimi, Gregorio

    2014-05-01

    Blood rheology is impaired in hypertensive patients. The alteration involves blood and plasma viscosity, and the erythrocyte behaviour is often abnormal. The hemorheological pattern appears to be related to some pathophysiological mechanisms of hypertension and to organ damage, in particular left ventricular hypertrophy and myocardial ischemia. Abnormalities have been observed in erythrocyte membrane fluidity, explored by fluorescence spectroscopy and electron spin resonance. This may be relevant for red cell flow in microvessels and oxygen delivery to tissues. Although blood viscosity is not a direct target of antihypertensive therapy, the rheological properties of blood play a role in the pathophysiology of arterial hypertension and its vascular complications.

  14. Children and Adolescent Obesity Associates with Pressure-Dependent and Age-Related Increase in Carotid and Femoral Arteries' Stiffness and Not in Brachial Artery, Indicative of Nonintrinsic Arterial Wall Alteration

    Science.gov (United States)

    García-Espinosa, Victoria; Curcio, Santiago; Castro, Juan Manuel; Arana, Maite; Giachetto, Gustavo; Chiesa, Pedro; Zócalo, Yanina

    2016-01-01

    Aim. To analyze if childhood obesity associates with changes in elastic, transitional, and/or muscular arteries' stiffness. Methods. 221 subjects (4–15 years, 92 females) were assigned to normal weight (NW, n = 137) or obesity (OB, n = 84) groups, considering their body mass index z-score. Age groups were defined: 4–8; 8–12; 12–15 years old. Carotid, femoral, and brachial artery local stiffness was determined through systodiastolic pressure-diameter and stress-strain relationships. To this end, arterial diameter and peripheral and aortic blood pressure (BP) levels and waveforms were recorded. Carotid-femoral, femoropedal, and carotid-radial pulse wave velocities were determined to evaluate aortic, lower-limb, and upper-limb regional arterial stiffness, respectively. Correlation analysis between stiffness parameters and BP was done. Results. Compared to NW, OB subjects showed higher peripheral and central BP and carotid and femoral stiffness, reaching statistical significance in subjects aged 12 and older. Arterial stiffness differences disappeared when levels were normalized for BP. There were no differences in intrinsic arterial wall stiffness (elastic modulus), BP stiffness relationships, and regional stiffness parameters. Conclusion. OB associates with BP-dependent and age-related increase in carotid and femoral (but not brachial) stiffness. Stiffness changes would not be explained by intrinsic arterial wall alterations but could be associated with the higher BP levels observed in obese children. PMID:27066273

  15. MORPHOLOGICAL STUDY OF MEDIAL CIRCUMFLEX FEMORAL ARTERY IN HUMAN CADAVERS

    Directory of Open Access Journals (Sweden)

    Brijesh R. Aghera

    2014-10-01

    Full Text Available Background: Medial circumflex femoral artery is an important branch of Profunda femoris artery. It is an important artery in supplying blood to the head and neck of the femur, the adductor muscles and form anastomosis around head of femur. So study of variation of medial circumflex femoral artery great value for surgeon and orthopaedic surgeries. Materials and Methods: The present study includes 102 lower limbs of adult formalin fixed human cadavers used for the routine dissection procedure for under graduate and post graduate students in the department of Anatomy, M.R. Medical College, KBN Medical college and H K E Homeopathic College, Gulbarga (India during 2011-2014.The study was done by dissection method as per Cunningham’s manual of practical Anatomy. Result: In present study, we found that 25 extremities (25.49% medial circumflex femoral artery was originated directly from femoral artery. In 10 extremities (9.80% a common trunk was observed form medial circumflex femoral with femoral artery. Normal study was observed in 66 extremities (64.70%. Conclusion: In present study and other past studies we conclude that knowledge of variation in this artery is very important to preventing injury to vessels during surgical procedures around hip joint and also has important value in plastic surgery operations as the vascular pedicle of grafts such as the transverse upper gracilis (TUG flap, medial thigh flap and medial circumflex femoral (gracilis perforator free flap. During case of selective arteriography in ischaemic necrosis of the femoral head to know the arterial supply of the femoral head it is used.

  16. Automated registration of multispectral MR vessel wall images of the carotid artery

    Energy Technology Data Exchange (ETDEWEB)

    Klooster, R. van ' t; Staring, M.; Reiber, J. H. C.; Lelieveldt, B. P. F.; Geest, R. J. van der, E-mail: rvdgeest@lumc.nl [Department of Radiology, Division of Image Processing, Leiden University Medical Center, 2300 RC Leiden (Netherlands); Klein, S. [Department of Radiology and Department of Medical Informatics, Biomedical Imaging Group Rotterdam, Erasmus MC, Rotterdam 3015 GE (Netherlands); Kwee, R. M.; Kooi, M. E. [Department of Radiology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht 6202 AZ (Netherlands)

    2013-12-15

    Purpose: Atherosclerosis is the primary cause of heart disease and stroke. The detailed assessment of atherosclerosis of the carotid artery requires high resolution imaging of the vessel wall using multiple MR sequences with different contrast weightings. These images allow manual or automated classification of plaque components inside the vessel wall. Automated classification requires all sequences to be in alignment, which is hampered by patient motion. In clinical practice, correction of this motion is performed manually. Previous studies applied automated image registration to correct for motion using only nondeformable transformation models and did not perform a detailed quantitative validation. The purpose of this study is to develop an automated accurate 3D registration method, and to extensively validate this method on a large set of patient data. In addition, the authors quantified patient motion during scanning to investigate the need for correction. Methods: MR imaging studies (1.5T, dedicated carotid surface coil, Philips) from 55 TIA/stroke patients with ipsilateral <70% carotid artery stenosis were randomly selected from a larger cohort. Five MR pulse sequences were acquired around the carotid bifurcation, each containing nine transverse slices: T1-weighted turbo field echo, time of flight, T2-weighted turbo spin-echo, and pre- and postcontrast T1-weighted turbo spin-echo images (T1W TSE). The images were manually segmented by delineating the lumen contour in each vessel wall sequence and were manually aligned by applying throughplane and inplane translations to the images. To find the optimal automatic image registration method, different masks, choice of the fixed image, different types of the mutual information image similarity metric, and transformation models including 3D deformable transformation models, were evaluated. Evaluation of the automatic registration results was performed by comparing the lumen segmentations of the fixed image and

  17. Abdominal wall repair with human acellular dermal autograft

    Directory of Open Access Journals (Sweden)

    Roel E. Genders

    2011-12-01

    Full Text Available Repair of abdominal wall defects in the presence of contamination or infection is a significant problem. The loss of tissue warrants enforcement of the abdominal wall, preferably by autologous material. However, autologous repair often requires extensive surgery. This paper presents a review of available literature of placement of an acellular human dermis to repair an abdominal fascia defect, in contaminated as well as in non-contaminated surgical fields. It is illustrated with a case report that describes the successful reconstruction of an infected abdominal wall defect with a human acellular dermis allograft. A systematic literature review was undertaken with searches performed in the Pubmed and Cochrane databases for the period up till March 2009, using the search terms Alloderm [Substance Name], Hernia [Mesh] and the key words acellular dermis, acellular dermal matrix, human acellular dermal allograft and abdominal wall defect. To assess methodological quality, each article was subjected to a modification of the methodological index for non-randomized studies (MINORS according to Slim et al. Two items from the original index were not included because none of the studies selected had an unbiased assessment of the study end points and in none of the studies was a prospective calculation of the study size performed. Seventeen studies were included in the review. Data were extracted regarding study design, number of patients, surgical technique, followup period, contaminated or non-contaminated area of the fascia defect, mortality and morbidity (hemorrhage, seroma, wound dehiscence, infection of the operative procedure, the longterm results (removal of the graft, reherniation and bulging and level of evidencey. A total of 169 short-term complications and 151 longterm complications occurred after 643 surgical procedures reconstructing both contaminated and clean abdominal wall defects by implantation of an HADA. Human acellular dermal allograft

  18. The relationship between wall shear stress distributions and intimal thickening in the human abdominal aorta

    Directory of Open Access Journals (Sweden)

    Butany Jagdish

    2003-11-01

    Full Text Available Abstract Purpose The goal of this work was to determine wall shear stress (WSS patterns in the human abdominal aorta and to compare these patterns to measurements of intimal thickness (IT from autopsy samples. Methods The WSS was experimentally measured using the laser photochromic dye tracer technique in an anatomically faithful in vitro model based on CT scans of the abdominal aorta in a healthy 35-year-old subject. IT was quantified as a function of circumferential and axial position using light microscopy in ten human autopsy specimens. Results The histomorphometric analysis suggests that IT increases with age and that the distribution of intimal thickening changes with age. The lowest WSS in the flow model was found on the posterior wall inferior to the inferior mesenteric artery, and coincided with the region of most prominent IT in the autopsy samples. Local geometrical features in the flow model, such as the expansion at the inferior mesenteric artery (common in younger individuals, strongly influenced WSS patterns. The WSS was found to correlate negatively with IT (r2 = 0.3099; P = 0.0047. Conclusion Low WSS in the abdominal aorta is co-localized with IT and may be related to atherogenesis. Also, rates of IT in the abdominal aorta are possibly influenced by age-related geometrical changes.

  19. Disturbed Laminar Blood Flow Vastly Augments Lipoprotein Retention in the Artery Wall: A Key Mechanism Distinguishing Susceptible From Resistant Sites.

    Science.gov (United States)

    Steffensen, Lasse Bach; Mortensen, Martin Bødtker; Kjolby, Mads; Hagensen, Mette Kallestrup; Oxvig, Claus; Bentzon, Jacob Fog

    2015-09-01

    Atherosclerosis develops initially at branch points and in areas of high vessel curvature. Moreover, experiments in hypercholesterolemic mice have shown that the introduction of disturbed flow in straight, atherosclerosis-resistant arterial segments turns them highly atherosclerosis susceptible. Several biomechanical mechanisms have been proposed, but none has been demonstrated. In the present study, we examined whether a causal link exists between disturbed laminar flow and the ability of the arterial wall to retain lipoproteins. Lipoprotein retention was detected at natural predilection sites of the murine thoracic aorta 18 hours after infusion of fluorescently labeled low-density lipoprotein. To test for causality between blood flow and the ability of these areas to retain lipoproteins, we manipulated blood flow in the straight segment of the common carotid artery using a constrictive collar. Disturbed laminar flow did not affect low-density lipoprotein influx, but increased the ability of the artery wall to bind low-density lipoprotein. Concordantly, disturbed laminar flow led to differential expression of genes associated with phenotypic modulation of vascular smooth muscle cells, increased expression of proteoglycan core proteins associated with lipoprotein retention, and of enzymes responsible for chondroitin sulfate glycosaminoglycan synthesis and sulfation. Blood flow regulates genes associated with vascular smooth muscle cell phenotypic modulation, as well as the expression and post-translational modification of lipoprotein-binding proteoglycan core proteins, and the introduction of disturbed laminar flow vastly augments the ability of a previously resistant, straight arterial segment to retain lipoproteins. © 2015 American Heart Association, Inc.

  20. Mechanical Interaction of an Expanding Coiled Stent with a Plaque-Containing Arterial Wall: A Finite Element Analysis.

    Science.gov (United States)

    Welch, Tré R; Eberhart, Robert C; Banerjee, Subhash; Chuong, Cheng-Jen

    2016-03-01

    Wall injury is observed during stent expansion within atherosclerotic arteries, related in part to stimulation of the inflammatory process. Wall stress and strain induced by stent expansion can be closely examined by finite element analysis (FEA), thus shedding light on procedure-induced sources of inflammation. The purpose of this work was to use FEA to examine the interaction of a coiled polymer stent with a plaque-containing arterial wall during stent expansion. An asymmetric fibrotic plaque-containing arterial wall model was created from intravascular ultrasound (IVUS) images of a diseased artery. A 3D model for a coil stent at unexpanded state was generated in SolidWorks. They were imported into ANSYS for FEA of combined stent expansion and fibrotic plaque-distortion. We simulated the stent expansion in the plaqued lumen by increasing balloon pressure from 0 to 12 atm in 1 atm step. At increasing pressure, we examined how the expanding stent exerts forces on the fibrotic plaque and vascular wall components, and how the latter collectively resist and balance the expansive forces from the stent. Results show the expanding coiled stent creates high stresses within the plaque and the surrounding fibrotic capsule. Lower stresses were observed in adjacent medial and adventitial layers. High principal strains were observed in plaque and fibrotic capsule. The results suggest fibrotic capsule rupture might occur at localized regions. The FEA/IVUS method can be adapted for routine examination of the effects of the expansion of selected furled stents against IVUS-reconstructed diseased vessels, to improve stent deployment practices.

  1. Low-density lipoprotein accumulation within a carotid artery with multilayer elastic porous wall: fluid-structure interaction and non-Newtonian considerations.

    Science.gov (United States)

    Deyranlou, Amin; Niazmand, Hamid; Sadeghi, Mahmood-Reza

    2015-09-18

    Low-density lipoprotein (LDL), which is recognized as bad cholesterol, typically has been regarded as a main cause of atherosclerosis. LDL infiltration across arterial wall and subsequent formation of Ox-LDL could lead to atherogenesis. In the present study, combined effects of non-Newtonian fluid behavior and fluid-structure interaction (FSI) on LDL mass transfer inside an artery and through its multilayer arterial wall are examined numerically. Navier-Stokes equations for the blood flow inside the lumen and modified Darcy's model for the power-law fluid through the porous arterial wall are coupled with the equations of mass transfer to describe LDL distributions in various segments of the artery. In addition, the arterial wall is considered as a heterogeneous permeable elastic medium. Thus, elastodynamics equation is invoked to examine effects of different wall elasticity on LDL distribution in the artery. Findings suggest that non-Newtonian behavior of filtrated plasma within the wall enhances LDL accumulation meaningfully. Moreover, results demonstrate that at high blood pressure and due to the wall elasticity, endothelium pores expand, which cause significant variations on endothelium physiological properties in a way that lead to higher LDL accumulation. Additionally, results describe that under hypertension, by increasing angular strain, endothelial junctions especially at leaky sites expand more dramatic for the high elastic model, which in turn causes higher LDL accumulation across the intima layer and elevates atherogenesis risk.

  2. Assessment of arterial wall enhancement for differentiation of parent artery disease from small artery disease: Comparison between histogram analysis and visual analysis on 3 dimensional contrast-enhanced T1-weighted turbo spin echo MR images at 3T

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jin Hee; Kim, Tae Won; Hwang, Eo Jin; Choi, Hyun Seok; Koo, Ja Seung; Shin, Yong Sam; Jung, So Lyung; Ahn, Kook Jin; Kim, Bum Soo [College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of)

    2017-04-15

    The purpose of this study was to compare the histogram analysis and visual scores in 3T MRI assessment of middle cerebral arterial wall enhancement in patients with acute stroke, for the differentiation of parent artery disease (PAD) from small artery disease (SAD). Among the 82 consecutive patients in a tertiary hospital for one year, 25 patients with acute infarcts in middle cerebral artery (MCA) territory were included in this study including 15 patients with PAD and 10 patients with SAD. Three-dimensional contrast-enhanced T1-weighted turbo spin echo MR images with black-blood preparation at 3T were analyzed both qualitatively and quantitatively. The degree of MCA stenosis, and visual and histogram assessments on MCA wall enhancement were evaluated. A statistical analysis was performed to compare diagnostic accuracy between qualitative and quantitative metrics. The degree of stenosis, visual enhancement score, geometric mean (GM), and the 90th percentile (90P) value from the histogram analysis were significantly higher in PAD than in SAD (p = 0.006 for stenosis, < 0.001 for others). The receiver operating characteristic curve area of GM and 90P were 1 (95% confidence interval [CI], 0.86-1.00). A histogram analysis of a relevant arterial wall enhancement allows differentiation between PAD and SAD in patients with acute stroke within the MCA territory.

  3. [Ultrastructure of the intima of human pial arteries in arterial hypertension].

    Science.gov (United States)

    Chertok, V M; Kotsiuba, A E; Babich, E V

    2009-01-01

    Ultrastructure of the intima of human pial arteries obtained from 5 male cadavers of practically healthy individuals and from 8 cadavers of the patients with the intravitally diagnosed grade I arterial hypertension (AH) was studied by scanning and transmission electron microscopy. AH was found to be associated with the remodeling of the intimal structural elements in the pial arteries. In most arteries, the changes were detected in the microrelief of the luminal surface and in the permeability of the vascular endothelial lining and of the subendothelial layer. During this remodeling, some endothelial cells were found in the state of structural and functional adaptation to the elevated arterial pressure, while the others were undergoing the dystrophic changes. The latter include the cells containing lipid inclusions, as well as the endothelial cells presumably in the state of apoptosis. The destruction of the intercellular junctions, the disturbances in the endothelium permeability contributed to the development of subendothelial layer edema, resulting in its significant thickening. This layer became looser and contained abundant collagen fibrils.

  4. Modelling and simulation of low-density lipoprotein transport through multi-layered wall of an anatomically realistic carotid artery bifurcation

    Science.gov (United States)

    Kenjereš, Saša; de Loor, Alexander

    2014-01-01

    A high concentration of low-density lipoprotein (LDL) is recognized as one of the principal risk factors for development of atherosclerosis. This paper reports on modelling and simulations of the coupled mass (LDL concentration) and momentum transport through the arterial lumen and the multi-layered arterial wall of an anatomically realistic carotid bifurcation. The mathematical model includes equations for conservation of mass, momentum and concentration, which take into account a porous layer structure, the biological membranes and reactive source/sink terms in different layers of the arterial wall, as proposed in Yang & Vafai (2006). A four-layer wall model of an arterial wall with constant thickness is introduced and initially tested on a simple cylinder geometry where realistic layer properties are specified. Comparative assessment with previously published results demonstrated proper implementation of the mathematical model. Excellent agreement for the velocity and LDL concentration distributions in the arterial lumen and in the artery wall are obtained. Then, an anatomically realistic carotid artery bifurcation is studied. This is the main novelty of the presented research. We find a strong dependence between underlying blood flow pattern (and consequently the wall shear stress distributions) and the uptake of the LDL concentration in the artery wall. The radial dependency of interactions between the diffusion, convection and chemical reactions within the multi-layered artery wall is crucial for accurate predictions of the LDL concentration in the media. It is shown that a four-layer wall model produced qualitatively good agreement with the experimental results of Meyer et al. (1996) in predicting levels of LDL within the media of a rabbit aorta under identical transmural pressure conditions. Finally, it is demonstrated that the adopted model represents a good initial platform for future numerical investigations of the initial stage of atherosclerosis for

  5. Contractility studies on isolated bovine choroidal small arteries: determination of the active and passive wall tension-internal circumference relation.

    Science.gov (United States)

    Delaey, C; Boussery, K; Van de Voorde, J

    2002-09-01

    Studies on isolated choroidal arteries could help to understand the regulatory mechanisms in the choroidal circulation. The aim of the present study was therefore to assess whether contractility studies on isolated choroidal arteries were feasible and to determine the active and passive wall tension-internal circumference relation of these arteries. This relation is essential for reliable further pharmacodynamic studies on these vessels. Isolated choroidal arteries were mounted on a wire myograph for isometric tension recording. After the vessel was mounted, the L(100) (the circumference of the vessel at a transmural pressure of 100 mmHg) was determined. Then the passive and active wall tension-internal circumference relation of the choroidal vessels was obtained by stepwise increasing the internal circumference. The changes in the internal circumference were expressed as a percentage of L(100). After each increase in circumference, the passive tone (in a calcium free medium), the spontaneous tone (in a Krebs--Ringer bicarbonate solution) and the active tone (in a solution containing K(+) 120 mM and prostaglandin F(2 alpha) 30 microM) was measured. The passive tone of the vessel increased exponentially with the circumference of the vessel. Both the spontaneous tone and the active tone also increased when the vessel was stretched. They peaked when the internal circumference approached 90% of the L(100) and diminished again when the circumference was further increased. The peak value of the active tension curve averaged 2.24+/-0.47 Nm(-1) (n=10). The passive tension was 0.57+/-0.08 Nm(-1) (n=10) at this circumference. The peak value of the spontaneous tension curve averaged 0.37+/-0.08 Nm(-1) (n=10). It can be concluded that in vitro contractility studies on isolated choroidal arteries are feasible. The optimal length or preload of the choroidal arteries is attained when the internal circumference of the artery is set to 90% of the L(100).

  6. ARTERIAL WALL OF THE ALBINO RAT: MORPHOMETRIC STRUCTURE AND GENERAL MORPHOPHYSIOLOGY

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    Antonio Marcos Orsi

    2015-07-01

    Full Text Available The histological structure and some morphometric parameters referring the aortic architecture of the adult albino rat were focused from the three segmental parts of the aorta comprising the thoracic ascendant and thoracic descendant parts, and the abdominal part of aorta immediately caudal to the renal arteries emergency. Slides containing transversal samples of aortic segments stained by Masson’s trichromes were studied and morphometrically analyzed through a Zeiss KS 300® system. The abdominal aortic segment showed a mixed pattern from the mural building formed by similar amounts of smooth muscle cells and connective matrix elements, being represented by collagen and elastic lamellae and fibers. However a classic elastic mural pattern was verified in the thoracic segments of the rat aorta, an intermingled pattern mainly occurred between the smooth muscle cells and matrix elements in all the segments of the rat aorta. The thickness of the aortic wall showed a numeric progressive lower from the ascendant part to the abdominal part of aorta. Similar pattern was verified for the number of elastic lamellae, which the major lamellar number observed could be related with the luminal vortex flow observed inside the ascendant aortic part. Also the aortic diameters verified decreased progressively from the ascendant to the abdominal part of aorta.

  7. Ex Vivo and in Silico Study of Human Common Carotid Arteries Pressure Response in Physiological and Inverted State

    Science.gov (United States)

    Piechna, A.; Cieślicki, K.; Lombarski, L.; Ciszek, B.

    2015-02-01

    Arterial walls are a multilayer structures with nonlinear material characteristics. Furthermore, residual stresses exist in unloaded state (zero-pressure condition) and they affect arterial behavior. To investigate these phenomena a number of theoretical and numerical studies were performed, however no experimental validation was proposed and realized yet. We cannot get rid of residual stresses without damaging the arterial segment. In this paper we propose a novel experiment to validate a numerical model of artery with residual stresses. The inspiration for our study originates from experiments made by Dobrin on dogs' arteries (1999). We applied the idea of turning the artery inside out. After such an operation the sequence of layer is reversed and the residual stresses are re-ordered. We performed several pressure-inflation tests on human Common Carotid Arteries (CCA) in normal and inverted configurations. The nonlinear responses of arterial behavior were obtained and compared to the numerical model. Computer simulations were carried out using the commercial software which applied the finite element method (FEM). Then, these results were discussed.

  8. Development of novel short-term heating angioplasty: thermal denaturation dynamics of collagen in artery wall

    Science.gov (United States)

    Shimazaki, N.; Tokunaga, H.; Katou, Y.; Hayashi, T.; Arai, T.

    2009-02-01

    We have studied to develop the new thermal angioplasty methodology, photo-thermo dynamic balloon angioplasty (PTDBA), which provides artery dilatation with short-term (collagen in artery media may be the important factor to attain sufficient artery dilatation for the PTDBA. In order to predict the optimum heating condition i.e. the balloon temperature and heating duration, we investigated the thermal denaturation dynamics of artery collagen in ex vivo. The extracted fresh porcine carotid artery was used. The temperature-dependent light scattering property and mechanical property of the artery specimen were simultaneously measured during artery temperature rising by specially made setup to assess the denaturation of arterial collagen. The change rate of the backscattered light intensity from the artery specimen; I(T)/I0 with 633nm was measured to evaluate the artery scattering property change with the thermal denaturation. The artery specimen was heated from 25°C to 80°C with constant temperature rising rate of 3°C/min. The measured I(T)/I0 was suddenly increased over 48°C. This boundary temperature might be the initiation temperature of the arterial collagen denaturation. We defined the variation of the I(T)/I0 as the collagen denaturation ratio, and calculated the reactive enthalpy by the chemical equilibrium theory. Since the calculated enthalpy was similar to the enthalpy in literature report, the variety of I(T)/I0 during the temperature rising might be attributed to the collagen conformational change due to the denaturation. In terms of the artery internal force measurement, the artery force was decreased with increasing of the artery temperature up to 65°C (i.e. softening), and increased over 65°C (i.e. shrinkage). We confirmed that the changes of the backscattered light (at 633nm in wavelength) from the artery might represent the artery collagen thermal denaturation degree.

  9. Characterizaton of the Vessel Geometry, Flow Mechanics and Wall Shear Stress in the Great Arteries of Wildtype Prenatal Mouse

    OpenAIRE

    Choon Hwai Yap; Xiaoqin Liu; Kerem Pekkan

    2014-01-01

    Characterizaton of the Vessel Geometry, Flow Mechanics and Wall Shear Stress in the Great Arteries of Wildtype Prenatal Mouse Choon Hwai Yap1, Xiaoqin Liu2, Kerem Pekkan3* 1 Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore, 2 Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America, 3 Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh...

  10. Carotid artery longitudinal wall motion is associated with local blood velocity and left ventricular rotational, but not longitudinal, mechanics.

    Science.gov (United States)

    Au, Jason S; Ditor, David S; MacDonald, Maureen J; Stöhr, Eric J

    2016-07-01

    Recent studies have identified a predictable movement pattern of the common carotid artery wall in the longitudinal direction. While there is evidence that the magnitude of this carotid artery longitudinal wall motion (CALM) is sensitive to cardiovascular health status, little is known about the determinants of CALM The purpose of this integrative study was to evaluate the contribution of left ventricular (LV) cardiac motion and local blood velocity to CALM Simultaneous ultrasound measurements of CALM, common carotid artery mean blood velocity (MBV), and left ventricular motion were performed in ten young, healthy individuals (6 males; 22 ± 1 years). Peak anterograde CALM occurred at a similar time as peak MBV (18.57 ± 3.98% vs. 18.53 ± 2.81% cardiac cycle; t-test: P = 0.94; ICC: 0.79, P longitudinal displacement was not associated with peak CALM (r = 0.11, P = 0.77). These results suggest that the rotational mechanical movement of the LV base may be closely associated with longitudinal mechanics in the carotid artery. This finding may have important implications for interpreting the complex relationship between ventricular and vascular function.

  11. Changes of glycoprotein and collagen immunolocalization in the uterine artery wall of postmenopausal women with and without pelvic organ prolapse.

    Science.gov (United States)

    Goepel, Christian; Johanna Kantelhardt, Eva; Karbe, Ina; Stoerer, Sandra; Dittmer, Juergen

    2011-05-01

    Pelvic organ prolapse (POP) is accompanied by an altered composition of the extracellular matrix (ECM). However, it is unclear whether the changed ECM is the cause or the consequence of POP, as stretching of the tissue may have an effect on the composition of the ECM. To address this question, we analyzed the connective tissues of the uterine artery wall of postmenopausal women with and without POP. The uterine artery wall is stretched in patients with POP, but this stretching is unlikely to cause the POP. Twenty-one women (13 with POP and 8 without POP) hospitalized for hysterectomy were included in this study. Tissue samples from the uterine artery were analyzed for collagen (types I, III, IV, V and VI) and other ECM proteins (fibronectin, laminin, tenascin, vitronectin and elastin) using immunofluorescence microscopy. Results revealed that uterine artery samples of women with prolapse showed a significantly weaker immunoreactivity to type VI collagen, vitronectin and elastin and a stronger immunostaining for type III collagen and tenascin as compared to control samples. Our results suggest that the ECM may be altered in response to mechanical stretch. Changes in the ECM composition as observed in POP may not necessarily be the reason for the development of pelvic floor relaxation in postmenopausal women. Copyright © 2010 Elsevier GmbH. All rights reserved.

  12. Upregulation of HMGB1 in wall of ruptured and unruptured human cerebral aneurysms: preliminary results.

    Science.gov (United States)

    Zhang, Dingding; Wu, Wei; Yan, Huiying; Jiang, Tianwei; Liu, Ming; Yu, Zhuang; Li, Hua; Hang, Chunhua

    2016-02-01

    A growing body of evidence suggests that inflammation plays a crucial role in cerebral aneurysm initiation, progression, and rupture. High-mobility group box 1 (HMGB1) is a non-histone nuclear protein that can serve as an alarmin to drive the pathogenesis of inflammatory disease. The purpose of this study was to investigate the expression of HMGB1 in the wall of ruptured and unruptured human cerebral aneurysms. Human cerebral aneurysms (25 ruptured and 16 unruptured) were immunohistochemically stained for HMGB1. As controls, four specimens of the middle cerebral arteries obtained at autopsy were also immunostained. Immunofluorescence double staining was used to determine HMGB1 cellular distribution. HMGB1 was nearly undetectable in the controls. All aneurysm tissues stained positive for HMGB1 monoclonal antibody, and expression of HMGB1 was more abundant in ruptured aneurysm tissue than unruptured aneurysms (p < 0.05). Furthermore, the expression of HMGB1 had no correlation with aneurysm size and time resected after the rupture. HMGB1 nuclear immunoreactivity was co-localized with immunoreactivity of CD3 in T lymphocytes, CD20 in B lymphocytes, CD68 in macrophages, α-SMA in smooth muscle cells, and CD31 in endothelial cells. Cytoplasmic HMGB1 localization was also detected in macrophages and T lymphocytes. Taken together, HMGB1 is expressed in the wall of human cerebral aneurysms and is more abundant in ruptured aneurysms than in unruptured ones. These data indicate a possible role of HMGB1 in the pathophysiology of human cerebral aneurysms.

  13. Composition of connective tissues and morphometry of vascular smooth muscle in arterial wall of DOCA-salt hypertensive rats - In relation with arterial remodeling.

    Science.gov (United States)

    Hayashi, Kozaburo; Shimizu, Emiko

    2016-05-01

    Hypertension (HT) was induced in Wistar rats aged 16 and 48 weeks by a deoxycortico-sterone acetate (DOCA)-salt procedure. Common carotid arteries were resected 16 weeks after, and their histological specimens were selectively stained for observations of collagen, elastin, and vascular smooth muscle (VSM) cells. Then, the fractions of collagen and elastin and their radial distributions, and the size and number of VSM cells were determined with an image analyzer. These results were compared with the results from age-matched, non-treated, normotensive (NT) animals and also with those from our previous biomechanical studies. In both age groups, there were no significant differences in the fractions of collagen and elastin, and the ratio of collagen to elastin content between HT and NT arteries. These results correspond well with our previous biomechanical results, which showed no significant difference in wall elasticity between HT and NT vessels. Moreover, in the innermost layer out of 4 layers bordered with thick elastic lamellae, the fraction of collagen was significantly greater in HT arteries than in NT ones, which is attributable to HT-related stress concentration in the layer. VSM cells were significantly hypertrophied and their content was increased by HT, although their total number in the media remained unchanged. The increased size and content of cells correspond to the enhancement of vascular tone and contractility in HT arteries.

  14. Muscle patterning in mouse and human abdominal wall development and omphalocele specimens of humans.

    Science.gov (United States)

    Nichol, Peter F; Corliss, Robert F; Yamada, Shigehito; Shiota, Kohei; Saijoh, Yukio

    2012-12-01

    Human omphalocele is a congenital defect of the abdominal wall in which the secondary abdominal wall structures (muscle and connective tissue) in an area centered around the umbilicus are replaced by a translucent membranous layer of tissue. Histological examination of omphalocele development and moreover the staging of normal human abdominal wall development has never been described. We hypothesized that omphalocele is the result of an arrest in the secondary abdominal wall development and predicted that we would observe delays in myoblast maturation and an arrest in secondary abdominal wall development. To look for evidence in support of our hypothesis, we performed a histological analysis of normal human abdominal wall development and compared this to mouse. We also conducted the first histological analysis of two human specimens with omphalocele. In these two omphalocele specimens, secondary abdominal wall development appears to have undergone an arrest around Carnegie Stage 19. In both specimens disruptions in the unidirectional orientation of myofibers were observed in the external and internal obliques, and rectus abdominis but not in the transversus abdominis. These latter findings support a model of normal abdominal wall development in which positional information instructs the orientation of myoblasts as they organize into individual muscle groups.

  15. K ATP channels in pig and human intracranial arteries

    DEFF Research Database (Denmark)

    Ploug, Kenneth Beri; Sørensen, Mette Aaskov; Strøbech, Lotte Bjørg

    2008-01-01

    Clinical trials suggest that synthetic ATP-sensitive K(+) (K(ATP)) channel openers may cause headache and migraine by dilating cerebral and meningeal arteries. We studied the mRNA expression profile of K(ATP) channel subunits in the pig and human middle meningeal artery (MMA) and in the pig middle...... cerebral artery (MCA). We determined the order of potency of four K(ATP) channel openers when applied to isolated pig MMA and MCA, and we examined the potential inhibitory effects of the Kir6.1 subunit specific K(ATP) channel blocker PNU-37883A on K(ATP) channel opener-induced relaxation of the isolated...... pig MMA and MCA. Using conventional RT-PCR, we detected the mRNA transcripts of the K(ATP) channel subunits Kir6.1 and SUR2B in all the examined pig and human intracranial arteries. Application of K(ATP) channel openers to isolated pig MMA and MCA in myographs caused a concentration...

  16. Characterization of the vessel geometry, flow mechanics and wall shear stress in the great arteries of wildtype prenatal mouse.

    Directory of Open Access Journals (Sweden)

    Choon Hwai Yap

    Full Text Available INTRODUCTION: Abnormal fluid mechanical environment in the pre-natal cardiovascular system is hypothesized to play a significant role in causing structural heart malformations. It is thus important to improve our understanding of the prenatal cardiovascular fluid mechanical environment at multiple developmental time-points and vascular morphologies. We present such a study on fetal great arteries on the wildtype mouse from embryonic day 14.5 (E14.5 to near-term (E18.5. METHODS: Ultrasound bio-microscopy (UBM was used to measure blood velocity of the great arteries. Subsequently, specimens were cryo-embedded and sectioned using episcopic fluorescent image capture (EFIC to obtain high-resolution 2D serial image stacks, which were used for 3D reconstructions and quantitative measurement of great artery and aortic arch dimensions. EFIC and UBM data were input into subject-specific computational fluid dynamics (CFD for modeling hemodynamics. RESULTS: In normal mouse fetuses between E14.5-18.5, ultrasound imaging showed gradual but statistically significant increase in blood velocity in the aorta, pulmonary trunk (with the ductus arteriosus, and descending aorta. Measurement by EFIC imaging displayed a similar increase in cross sectional area of these vessels. However, CFD modeling showed great artery average wall shear stress and wall shear rate remain relatively constant with age and with vessel size, indicating that hemodynamic shear had a relative constancy over gestational period considered here. CONCLUSION: Our EFIC-UBM-CFD method allowed reasonably detailed characterization of fetal mouse vascular geometry and fluid mechanics. Our results suggest that a homeostatic mechanism for restoring vascular wall shear magnitudes may exist during normal embryonic development. We speculate that this mechanism regulates the growth of the great vessels.

  17. Hemodynamic analysis in an idealized artery tree: differences in wall shear stress between Newtonian and non-Newtonian blood models.

    Science.gov (United States)

    Weddell, Jared C; Kwack, JaeHyuk; Imoukhuede, P I; Masud, Arif

    2015-01-01

    Development of many conditions and disorders, such as atherosclerosis and stroke, are dependent upon hemodynamic forces. To accurately predict and prevent these conditions and disorders hemodynamic forces must be properly mapped. Here we compare a shear-rate dependent fluid (SDF) constitutive model, based on the works by Yasuda et al in 1981, against a Newtonian model of blood. We verify our stabilized finite element numerical method with the benchmark lid-driven cavity flow problem. Numerical simulations show that the Newtonian model gives similar velocity profiles in the 2-dimensional cavity given different height and width dimensions, given the same Reynolds number. Conversely, the SDF model gave dissimilar velocity profiles, differing from the Newtonian velocity profiles by up to 25% in velocity magnitudes. This difference can affect estimation in platelet distribution within blood vessels or magnetic nanoparticle delivery. Wall shear stress (WSS) is an important quantity involved in vascular remodeling through integrin and adhesion molecule mechanotransduction. The SDF model gave a 7.3-fold greater WSS than the Newtonian model at the top of the 3-dimensional cavity. The SDF model gave a 37.7-fold greater WSS than the Newtonian model at artery walls located immediately after bifurcations in the idealized femoral artery tree. The pressure drop across arteries reveals arterial sections highly resistive to flow which correlates with stenosis formation. Numerical simulations give the pressure drop across the idealized femoral artery tree with the SDF model which is approximately 2.3-fold higher than with the Newtonian model. In atherosclerotic lesion models, the SDF model gives over 1 Pa higher WSS than the Newtonian model, a difference correlated with over twice as many adherent monocytes to endothelial cells from the Newtonian model compared to the SDF model.

  18. Hemodynamic analysis in an idealized artery tree: differences in wall shear stress between Newtonian and non-Newtonian blood models.

    Directory of Open Access Journals (Sweden)

    Jared C Weddell

    Full Text Available Development of many conditions and disorders, such as atherosclerosis and stroke, are dependent upon hemodynamic forces. To accurately predict and prevent these conditions and disorders hemodynamic forces must be properly mapped. Here we compare a shear-rate dependent fluid (SDF constitutive model, based on the works by Yasuda et al in 1981, against a Newtonian model of blood. We verify our stabilized finite element numerical method with the benchmark lid-driven cavity flow problem. Numerical simulations show that the Newtonian model gives similar velocity profiles in the 2-dimensional cavity given different height and width dimensions, given the same Reynolds number. Conversely, the SDF model gave dissimilar velocity profiles, differing from the Newtonian velocity profiles by up to 25% in velocity magnitudes. This difference can affect estimation in platelet distribution within blood vessels or magnetic nanoparticle delivery. Wall shear stress (WSS is an important quantity involved in vascular remodeling through integrin and adhesion molecule mechanotransduction. The SDF model gave a 7.3-fold greater WSS than the Newtonian model at the top of the 3-dimensional cavity. The SDF model gave a 37.7-fold greater WSS than the Newtonian model at artery walls located immediately after bifurcations in the idealized femoral artery tree. The pressure drop across arteries reveals arterial sections highly resistive to flow which correlates with stenosis formation. Numerical simulations give the pressure drop across the idealized femoral artery tree with the SDF model which is approximately 2.3-fold higher than with the Newtonian model. In atherosclerotic lesion models, the SDF model gives over 1 Pa higher WSS than the Newtonian model, a difference correlated with over twice as many adherent monocytes to endothelial cells from the Newtonian model compared to the SDF model.

  19. Measurements of ultrasonic pulse distortion produced by human chest wall.

    Science.gov (United States)

    Hinkelman, L M; Szabo, T L; Waag, R C

    1997-04-01

    Ultrasonic wavefront distortion produced by transmission through human chest wall specimens was measured over a two-dimensional aperture. Measured pulse wavefronts were sometimes disrupted by secondary wavefronts produced by interaction between the transmitted pulses and the bone and cartilage structures of the rib cage. The secondary wavefronts produced large distortions in the received waveforms and interfered with the determination of the wavefront distortion caused by soft-tissue inhomogeneities. The effects of secondary wavefronts were minimized by reducing the region of analysis. Differences in arrival time and energy level between these restricted regions and references that account for geometric delay and spreading were computed. Spectral changes were assessed by calculating a waveform similarity factor that is decreased from 1.0 by changes in waveform shape. For 16 different intercostal spaces, the arrival time fluctuations of the measured waveforms had an average (+/-s.d.) rms value of 21.3 (+/-8.4) ns and an average correlation length of 2.50 (+/-0.62) mm. The energy level fluctuations had an average rms value of 1.57 (+/-0.45) dB and an average correlation length of 1.98 (+/-0.33) mm, and the average waveform similarity factor was 0.964 (+/-0.012). For soft-tissue inhomogeneities in chest wall specimens, the average rms arrival time and energy level fluctuations were less than half those measured for the abdominal wall. However, although the average correlation length of the arrival time fluctuations was less than half that found for the abdominal wall, the average correlation length of the energy level fluctuations was similar to that of the abdominal wall.

  20. Arterial wall metabolism in experimental hypertension of coarctation of the aorta of short duration.

    Science.gov (United States)

    Hollander, W; Kramsch, D M; Farmelant, M; Madoff, I M

    1968-05-01

    Coarctation of the mid-thoracic aorata was surgically produced in mongrel dogs which were sacrificed from 4-12 wk after the operation. As compared to the findings in control animals, the sodium, chloride, and water content of the hypetensive portion of the coarcted thoracic aorta was significantly elevated, whereas the electrolyte and water content of the relatively normotensive portion of the coarcted aorta was normal. The sodium, potassium, and water content of the pulmonary artery, skeletal muscle, and cardiac muscle of the coarcted dog was not altered. These observations suggest that an elevated arterial pressure may influence the electrolyte and water composition of the arteries. The arterial pressure also may influence the content and synthesis of acid mucopolysaccharides (MPS) in the arteries since the content of sulfated MPS and the incorporation of injected radiosulfate into sulfated MPS were significantly increased in the hypertensive portion of the coarcted thoracic aorta but were significantly reduced in the relatively normotensive ("hypotensive") portion of the coarcted aorta. The observed increase in MPS may have been a factor directly responsible for the increase in the sodium content of the hypertensive aorta since MPS can act as polyelectrolytes and bind cations. Although the arterial pressure may influence certain metabolic functions in the arteries, it did not appear to have a direct effect on the arterial lipids since the lipid content of the hypertensive and of the relatively normotensive portions of the coarcted aorta were comparable to the values found in the normal aorta.

  1. Tomographic particle image velocimetry investigation of the flow in a modeled human carotid artery bifurcation

    Science.gov (United States)

    Buchmann, N. A.; Atkinson, C.; Jeremy, M. C.; Soria, J.

    2011-04-01

    Hemodynamic forces within the human carotid artery are well known to play a key role in the initiation and progression of vascular diseases such as atherosclerosis. The degree and extent of the disease largely depends on the prevailing three-dimensional flow structure and wall shear stress (WSS) distribution. This work presents tomographic PIV (Tomo-PIV) measurements of the flow structure and WSS in a physiologically accurate model of the human carotid artery bifurcation. The vascular geometry is reconstructed from patient-specific data and reproduced in a transparent flow phantom to demonstrate the feasibility of Tomo-PIV in a complex three-dimensional geometry. Tomographic reconstruction is performed with the multiplicative line-of-sight (MLOS) estimation and simultaneous multiplicative algebraic reconstruction (SMART) technique. The implemented methodology is validated by comparing the results with Stereo-PIV measurements in the same facility. Using a steady flow assumption, the measurement error and RMS uncertainty are directly inferred from the measured velocity field. It is shown that the measurement uncertainty increases for increasing light sheet thickness and increasing velocity gradients, which are largest near the vessel walls. For a typical volume depth of 6 mm (or 256 pixel), the analysis indicates that the velocity derived from 3D cross-correlation can be measured within ±2% of the maximum velocity (or ±0.2 pixel) near the center of the vessel and within ±5% (±0.6 pixel) near the vessel wall. The technique is then applied to acquire 3D-3C velocity field data at multiple axial locations within the carotid artery model, which are combined to yield the flow field and WSS in a volume of approximately 26 mm × 27 mm × 60 mm. Shear stress is computed from the velocity gradient tensor and a method for inferring the WSS distribution on the vessel wall is presented. The results indicate the presence of a complex and three-dimensional flow structure, with

  2. Effect of atherosclerosis on thermo-mechanical properties of arterial wall and its repercussion on plaque instability.

    Science.gov (United States)

    Guinea, G V; Atienza, J M; Fantidis, P; Rojo, F J; Ortega, A; Torres, M; Gonzalez, P; Elices, M L; Hayashi, K; Elices, M

    2009-03-06

    Data from the literature report febrile reactions prior to myocardial infarction in patients with normal coronary arteries and that coronary syndromes seem to be triggered by bacterial and viral infections, being fever the common symptom. The thermo-mechanical behavior of thoracic aortas of New Zealand White rabbits with different degrees of atherosclerosis was measured by means of pressure-diameter tests at different temperatures. Specific measurements of the thermal dilatation coefficient of atheroma plaques were performed by means of tensile tests. Results show a different thermo-mechanical behavior, the dilatation coefficient of atheroma plaque being at least twice that of the arterial wall. Temperature-induced mechanical stress at the plaque-vessel interface could be enough to promote plaque rupture. Therefore, increases of corporal temperature, either local or systemic, can play a role in increasing the risk of acute coronary syndromes and deserve a more comprehensive study.

  3. Assessment of myocardial segmental function with coronary artery stenosis in multi-vessel coronary disease patients with normal wall motion.

    Science.gov (United States)

    Xie, M-Y; Lv, Q; Wang, J; Yin, J-B

    2016-04-01

    To discover the impact of the various degrees of coronary artery stenosis (CAD) on the left ventricular systolic dysfunction in steady state with quantitative analysis of the regional systolic myocardium in longitudinal, radial and circumferential direction in patients with coronary artery disease by two-dimensional speckle tracking imaging (STI). Forty-three normal wall motion-multi vessel coronary artery disease (NWM-MVD) patients labeled as the experimental groups and forty-two subjects with little risk of CAD marked as the control group were enrolled in this study. The two-dimensional STI was obtained in the apical long axis and three levels of the short axis of the left ventricle. The left ventricular wall was divided into 18 segments. The affected myocardia were divided into three groups: group B (coronary stenosis degree ≤50%), group C (coronary stenosis degree 50%-99%)and group D (coronary stenosis degree ≥99%). Using the Q-analysis software, the longitudinal, radial and circumferential systolic strain (SL, SR, SC) and strain ratio (SrL, SrR, SrC) of the myocardium were analyzed. The bradycardia in the NWM-MVD group is greater than that in the control group (16/43 vs. 7/42, p coronary stenosis degree ≤50%), group C (coronary stenosis degree 50%-99%)and group D (coronary stenosis degree ≥99%), especially the longitudinal and radial systolic function, even though they had normal wall motion. The SrL equaled 1.085 for the cut-off value, and the sums (1.348) of sensitivity (0.673) and specificity (0.675) were the greatest. Bradycardia might be a compensatory mechanism in NWM-MVD patients.

  4. Arterial bending angle and wall morphology correlate with slow coronary flow: Determination with multidetector CT coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Kantarci, Mecit, E-mail: akkanrad@hotmail.com [Department of Radiology, Medical Faculty, Atatuerk University, Erzurum (Turkey); Guendogdu, Fuat [Department of Cardiology, Medical Faculty, Atatuerk University, Erzurum (Turkey); Doganay, Selim [Department of Radiology, Medical Faculty, Erciyes University, Kayseri (Turkey); Duran, Cihan [Department of Radiology, Bilim University, Florence Nightingale Hospital, Istanbul (Turkey); Kalkan, M. Emin [Department of Cardiology, Medical Faculty, Atatuerk University, Erzurum (Turkey); Sagsoz, M. Erdem [Department of Radiology, Medical Faculty, Atatuerk University, Erzurum (Turkey); Kucuk, Osman [Department of Electronic Engineering, Engineering Faculty, Atatuerk University, Erzurum (Turkey); Karakaya, Afak [Department of Radiology, Medical Faculty, Atatuerk University, Erzurum (Turkey); Kucuk, Ahmet [Department of Mathematics, Science Faculty, Atatuerk University, Erzurum (Turkey); Akguen, Metin [Department of Chest, Medical Faculty, Atatuerk University, Erzurum (Turkey)

    2011-01-15

    Background and purpose: The purpose of this study was to assess angulations and vessel wall morphology that could lead to bending head loss in the RCA and LMCA arteries of patients with slow coronary flow (SCF) evaluated by MDCT coronary angiography. Methods: The study involved 51 patients (45 males, mean age: 59.6 years) who were diagnosed with SCF by coronary angiography. Diagnosis of SCF was based on thrombolysis in myocardial infarction (TIMI) frame count. Fifty-one patients with absence of slow flow were selected as the control group. The angulations of the main coronary arteries with the aorta were measured from the axial images obtained through MDCT coronary angiography, and the findings were recorded. In addition, the coronary artery walls of these patients were evaluated. For statistical analysis, SPSS for Windows 10.0 (SPSS Inc., Chicago, IL) was used. For comparisons of the angles, either independent samples t test or the Mann-Whitney U test was used where appropriate. Results: The results of the study indicated that 38 patients had SCF in the LAD. Comparisons of patients with SCF with the controls revealed that in the patients with SCF, the mean angle of the LMCA with the aorta (40.9 {+-} 20.5{sup o}) was statistically significantly smaller than the mean angle of the LMCA with the aorta in the control cases (71.8 {+-} 11{sup o}). In 12 patients, slow flow was detected in the RCA. Those with slow flow in the RCA had significantly smaller angles (mean: 33.2 {+-} 20.4{sup o}) than the other cases (mean: 78.9 {+-} 10.7{sup o}). Conclusion: A small angle of origin of the main coronary arteries from the aorta, measured on MDCT examinations is correlated with slow blood flow in those vessels, as calculated by the TIMI frame count in catheter coronary angiography.

  5. Arterial grafts exhibiting unprecedented cellular infiltration and remodeling in vivo: the role of cells in the vascular wall.

    Science.gov (United States)

    Row, Sindhu; Peng, Haofan; Schlaich, Evan M; Koenigsknecht, Carmon; Andreadis, Stelios T; Swartz, Daniel D

    2015-05-01

    To engineer and implant vascular grafts in the arterial circulation of a pre-clinical animal model and assess the role of donor medial cells in graft remodeling and function. Vascular grafts were engineered using Small Intestinal Submucosa (SIS)-fibrin hybrid scaffold and implanted interpositionally into the arterial circulation of an ovine model. We sought to demonstrate implantability of SIS-Fibrin based grafts; examine the remodeling; and determine whether the presence of vascular cells in the medial wall was necessary for cellular infiltration from the host and successful remodeling of the implants. We observed no occlusions or anastomotic complications in 18 animals that received these grafts. Notably, the grafts exhibited unprecedented levels of host cell infiltration that was not limited to the anastomotic sites but occurred through the lumen as well as the extramural side, leading to uniform cell distribution. Incoming cells remodeled the extracellular matrix and matured into functional smooth muscle cells as evidenced by expression of myogenic markers and development of vascular reactivity. Interestingly, tracking the donor cells revealed that their presence was beneficial but not necessary for successful grafting. Indeed, the proliferation rate and number of donor cells decreased over time as the vascular wall was dominated by host cells leading to significant remodeling and development of contractile function. These results demonstrate that SIS-Fibrin grafts can be successfully implanted into the arterial circulation of a clinically relevant animal model, improve our understanding of vascular graft remodeling and raise the possibility of engineering mural cell-free arterial grafts. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. [The antithrombophilic complex of the arterial wall in the therapy of obliterating arteriopathies in lower limbs (author's transl)].

    Science.gov (United States)

    Catalano, M; Carzaniga, G; Fiore, G; Lunardi, L; Libretti, A

    1980-01-01

    For 30 patients affected by obliterating arteriopathy in lower limbs, the use was made of an antithrombophilic complex of the arterial wall (aorta) consisting of both anti-coagulating and fybrinolytic principles. The results obtained, as regards both subjective and objective symptomatology, clearly showed a considerable increase in the hematic flow in the limbs affected by arteriopathy. Also the flow of the collateral circulation was improved. At the same time, a meaningful reduction in the abnormal cholesterol values was found. The preparation showed no antigenic activity. As or the oral administration, this preparation proved to be an effective one. Tolerance was completely satisfactory.

  7. On-line assessment of regional ventricular wall motion by transesophageal echocardiography with color kinesis during minimally invasive coronary artery bypass grafting.

    Science.gov (United States)

    Kotoh, K; Watanabe, G; Ueyama, K; Uozaki, M; Suzuki, M; Misaki, T; Wakasugi, M; Ito, Y

    1999-05-01

    Our objective was to determine the changes in regional ventricular wall motion during minimally invasive direct coronary artery bypass grafting by color kinesis using transesophageal echocardiography. Minimally invasive coronary artery bypass grafting was performed in 34 patients, during which transesophageal echocardiography was used. Thirteen patients had isolated disease of the left anterior descending artery. Regional ventricular wall motion was analyzed by color kinesis with the SONOS 2500 transesophageal echocardiograph (Hewlett-Packard Co, Andover, Mass). On-line assessment of regional wall motion was continued during the operation. Wall motion abnormalities during ischemia were present in 4 cases, left ventricular mid-anterior hypokinesis in 3 cases, and left ventricular apical-lateral hypokinesis in 1 case. In all cases, wall motion was maintained after bypass. In patients with total coronary occlusion, changes in wall motion did not occur during anastomosis. Color kinesis allowed us to evaluate the change in regional ventricular wall motion induced by myocardial ischemia during minimally invasive coronary artery bypass grafting both objectively and quantitatively.

  8. Examination of nanoparticles as a drug carrier on blood flow through catheterized composite stenosed artery with permeable walls.

    Science.gov (United States)

    Ijaz, S; Nadeem, S

    2016-09-01

    In this paper, we have discussed the influence of copper nanoparticles on a blood flow through composite stenosed artery with permeable walls. The nature of blood is discussed mathematically by considering it as viscous nanofluid. The study is carried out for a blood vessel under mild stenosis approximations and expressions of the temperature, velocity, resistance impedance to flow, wall shear stress and the pressure gradient is obtained by using corresponding boundary conditions. Results for the effects of permeability on blood flow through composite stenosis have been discussed graphically. The considered analysis also summarizes that the drug copper nanoparticles are efficient to reduce hemodynamics of stenosis and could be helpful to predict important uses for biomedical applications. Results indicate that nanoparticles are helpful as drug carriers to minimize the effects of resistance impedance to blood flow or coagulation factors due to stenosis.

  9. Mechanobiology of LDL mass transport in the arterial wall under the effect of magnetic field, part I: Diffusion rate

    Science.gov (United States)

    Aminfar, Habib; Mohammadpourfard, Mousa; Khajeh, Kosar

    2017-03-01

    It is well-known that the Low Density Lipoprotein (LDL) can accumulate and penetrate into the arterial wall. Here, we have investigated the diffusion rate of macromolecules across the porous layer of blood vessel under the effects of magnetic force. By using a finite volume technique, it was found that magnetic field makes alterations in diffusion rate of LDLs, also surface concentration of macromolecules on the walls. As well, the influence of different value of Re and Sc number in the presence of a magnetic field have shown as nondimensional concentration profiles. Magnetic field considered as a body force, porous layer simulated by using Darcy's law and the blood regarded as nano fluid which was examined as a single phase model.

  10. Characterization of optimal resting tension in human pulmonary arteries

    Science.gov (United States)

    Hussain, Azar; Bennett, Robert T; Chaudhry, Mubarak A; Qadri, Syed S; Cowen, Mike; Morice, Alyn H; Loubani, Mahmoud

    2016-01-01

    AIM To determine the optimum resting tension (ORT) for in vitro human pulmonary artery (PA) ring preparations. METHODS Pulmonary arteries were dissected from disease free sections of the resected lung in the operating theatre and tissue samples were directly sent to the laboratory in Krebs-Henseleit solution (Krebs). The pulmonary arteries were then cut into 2 mm long rings. PA rings were mounted in 25 mL organ baths or 8 mL myograph chambers containing Krebs compound (37 °C, bubbled with 21% O2: 5% CO2) to measure changes in isometric tension. The resting tension was set at 1-gram force (gf) with vessels being left static to equilibrate for duration of one hour. Baseline contractile reactions to 40 mmol/L KCl were obtained from a resting tension of 1 gf. Contractile reactions to 40 mmol/L KCl were then obtained from stepwise increases in resting tension (1.2, 1.4, 1.6, 1.8 and 2.0 gf). RESULTS Twenty PA rings of internal diameter between 2-4 mm were prepared from 4 patients. In human PA rings incrementing the tension during rest stance by 0.6 gf, up to 1.6 gf significantly augmented the 40 mmol/L KCl stimulated tension. Further enhancement of active tension by 0.4 gf, up to 2.0 gf mitigate the 40 mmol/L KCl stimulated reaction. Both Myograph and the organ bath demonstrated identical conclusions, supporting that the radial optimal resting tension for human PA ring was 1.61 g. CONCLUSION The radial optimal resting tension in our experiment is 1.61 gf (15.78 mN) for human PA rings. PMID:27721938

  11. Computerized flow and vessel wall analyses of coronary arteries for detection of non-calcified plaques in coronary CT angiography

    Science.gov (United States)

    Wei, Jun; Zhou, Chuan; Chan, Heang-Ping; Chughtai, Aamer; Agarwal, Prachi; Hadjiiski, Lubomir; Kazerooni, Ella

    2016-03-01

    The buildup of non-calcified plaques (NCP) that are vulnerable to rupture in coronary arteries is a risk for myocardial infarction. We are developing a computer-aided detection (CADe) system to assist radiologists in detecting NCPs in cCTA. A major challenge of NCP detection is the large number of false positives (FPs) caused by the small sized coronary arteries, image noise and artifacts. In this study, our purpose is to design new image features to reduce FPs. A data set of 98 cCTA scans was retrospectively collected from patient files. We first used vessel wall analysis, in which topological features were extracted from vessel wall and fused with a support-vector machine, to identify the NCP candidates from the segmented coronary tree. Computerized flow dynamic (CFD) features that characterize the change in blood flow due to the presence of plaques and a vascular cross-sectional (VCS) feature that quantifies the presence of low attenuation region at the vessel wall were designed for FP reduction. Using a leave-one-out resampling method, a support vector machine classifier was trained to merge the features into a NCP likelihood score using the vessel wall features alone or in combination with the new CDF and VCS features. The performance of the new features in classification of true NCPs and FPs was evaluated by the area under the receiver operating characteristic (ROC) curve (AUC). Without the new CFD and VCS features, the test AUC was 0.84+/-0.01. The AUC was improved to 0.88+/-0.01 with the addition of the new features. The improvement was statistically significant (p < 0.001). The study indicated that the new flow dynamic and vascular cross-sectional features were useful for differentiation of NCPs from FPs in cCTA.

  12. Relationship between heart rate variability, blood pressure and arterial wall properties during air and oxygen breathing in healthy subjects.

    Science.gov (United States)

    Graff, Beata; Szyndler, Anna; Czechowicz, Krzysztof; Kucharska, Wiesława; Graff, Grzegorz; Boutouyrie, Pierre; Laurent, Stephane; Narkiewicz, Krzysztof

    2013-11-01

    Previous studies reported that normobaric hyperoxia influences heart rate, arterial pressure, cardiac output and systemic vascular resistance, but the mechanisms underlying these changes are still not fully understood. Several factors are considered including degeneration of endothelium-derived nitric oxide by reactive oxygen species, the impact of oxygen-free radicals on tissues and alterations of autonomic nervous system function. Recently, new devices for the detailed non-invasive assessment of large and small arteries have been developed. Therefore, the aim of our study was to assess heart rate variability (HRV) as a potential indicator of autonomic balance and its relation to blood pressure and vascular properties during medical air (MAB) and 100% oxygen breathing (OXB) in healthy volunteers. In 12 healthy subjects we assessed heart rate and blood pressure variability, baroreflex sensitivity, respiratory frequency, common carotid artery diameter and its wall distensibility, as well as changes in the digital artery pulse waveform, stroke index and systemic vascular resistance during MAB and OXB. Mean and systolic blood pressure have increased significantly while digital pulse amplitude and carotid artery diameter were significantly lower during hyperoxia. Heart rate variability measures did not differ during MAB and OXB. However, the correlations between spectral HRV components and those hemodynamic parameters which have changed due to hyperoxia varied substantially during MAB (correlated significantly) and OXB (no significant correlations were noted). Our findings suggest that autonomic nervous system might not be the main mediator of the cardiovascular changes during 100% oxygen breathing in healthy subjects. It seems that the direct vascular responses are initial consequences of hyperoxia and other cardiovascular parameter alterations are secondary to them. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Extremal states of energy of a double-layered thick-walled tube - application to residually stressed arteries.

    Science.gov (United States)

    Waffenschmidt, Tobias; Menzel, Andreas

    2014-01-01

    Various biological tissues are designed to optimally support external loads for complex geometries and mechanobiological structures. This results in complex microstructures of such materials. The design of, for instance, (healthy) arteries, which are in the focus of this work, is characterised by a residually stressed fibre-reinforced multi-layered composite with highly non-linear elastic response. The complex interaction of material properties with the geometry and residual stress effects enables the optimal support under different blood pressures, respectively blood flow, within the vessel. The fibres reinforcing the arterial wall, as well as residual stresses present in the vessel, strongly influence its overall behaviour and performance. Turn-over and remodelling processes of the collagenous fibres occurring in the respective layers - either resulting from natural growth phenomena or from artificially induced changes in loading condition such as stent deployment - support the optimisation of the multi-layered composite structure of arteries for the particular loading conditions present in the artery. Within this contribution, the overall energetic properties of an artery are discussed by means of the inflation, bending and extension of a double-layered cylindrical tube. Different states of residual stresses and different fibre orientations are considered so that, for instance, representative fibre angles that result in extremal states of the total potential energy can be identified. In view of turn-over and remodelling processes, these orientations are considered to constitute preferred directions of fibre alignment. In summary, the main goal of this work is to calculate optimal material, structural and loading parameters by concepts of energy-minimisation. Several numerical studies show that the obtained values - such as the fibre orientations, the residual axial stretch and the opening angle - are in good agreement with respective physiological parameters

  14. Heparin inhibits human coronary artery smooth muscle cell migration.

    Science.gov (United States)

    Kohno, M; Yokokawa, K; Yasunari, K; Minami, M; Kano, H; Mandal, A K; Yoshikawa, J

    1998-09-01

    Heparin, an anticoagulant, has been shown to reduce neointimal proliferation and restenosis following vascular injury in experimental studies, but the clinical trials of heparin in coronary balloon angioplasty have been negative. The current study, therefore, examined the effect of heparin on basal or stimulated migration by serum and platelet-derived growth factor (PDGF)-BB in cultured human coronary artery smooth muscle cells (SMCs) by Boyden's chamber method. In addition, the reversibility of the heparin effect on human coronary artery SMC migration was examined. Fetal calf serum (FCS) and PDGF-BB stimulated SMC migration in a concentration-dependent manner. Heparin in moderate to high concentration (10 to 100 U/mL) exhibited concentration-related inhibition of FCS- and PDGF-BB-stimulated SMC migration; however, a low concentration (1 U/mL) of heparin had no inhibitory effects. Heparin also had weak inhibitory effects on nonstimulated SMC migration. The SMCs that were exposed to a high concentration (100 U/mL) of heparin for 6 hours were capable of migrating after a short lag period of removal of heparin from the culture medium. These SMCs also showed recovery of responses to FCS and PDGF-BB by migrating significantly greater than the nonstimulated level. Furthermore, heparin-containing medium did not contain detached cells. These results indicate that heparin inhibits human coronary artery SMC migration, especially when stimulated by FCS or PDGF-BB, and that this inhibitory effect of heparin is reversible and not simply a function of killing cells.

  15. [Pulmonary arterial hypertension associated to human immunodeficiency virus].

    Science.gov (United States)

    Sandoval-Gutiérrez, José Luis; Santos-Martínez, Luis Efren; Rodríguez-Silverio, Juan; Baranda-Tovar, Francisco Martín; Rivera-Rosales, Rosa María; Flores-Murrieta, Francisco Javier

    2015-01-01

    From the advent of the highly effective antiretroviral treatment, the life expectancy of patients with human immunodeficiency virus has increased significantly. At present, the causes of death are non-infectious complications. Between them, the pulmonary arterial hypertension has a special importance. It is important early detection to establish the therapeutic, with the objective of preventing a fatal outcome to future. Copyright © 2013 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

  16. Poisson׳s ratio of arterial wall - Inconsistency of constitutive models with experimental data.

    Science.gov (United States)

    Skacel, Pavel; Bursa, Jiri

    2016-02-01

    Poisson׳s ratio of fibrous soft tissues is analyzed in this paper on the basis of constitutive models and experimental data. Three different up-to-date constitutive models accounting for the dispersion of fibre orientations are analyzed. Their predictions of the anisotropic Poisson׳s ratios are investigated under finite strain conditions together with the effects of specific orientation distribution functions and of other parameters. The applied constitutive models predict the tendency to lower (or even negative) out-of-plane Poisson׳s ratio. New experimental data of porcine arterial layer under uniaxial tension in orthogonal directions are also presented and compared with the theoretical predictions and other literature data. The results point out the typical features of recent constitutive models with fibres concentrated in circumferential-axial plane of arterial layers and their potential inconsistence with some experimental data. The volumetric (in)compressibility of arterial tissues is also discussed as an eventual and significant factor influencing this inconsistency.

  17. The use of an occlusion perfusion catheter to deliver paclitaxel to the arterial wall.

    Science.gov (United States)

    Atigh, Marzieh K; Turner, Emily; Christians, Uwe; Yazdani, Saami K

    2017-08-01

    Nonstent drug delivery platforms have recently emerged as an alternative treatment of peripheral arterial disease. Perfusion catheters have the potential to directly deliver antiproliferative agents to the medial arterial layer to prevent restenosis. The purpose of this study was to therefore determine the effectiveness of a perfusion catheter to deliver paclitaxel, a proven antiproliferative agent, to combat restenosis. A benchtop model was utilized to determine the varying parameters of a novel occlusion perfusion catheter to maximize paclitaxel delivery using pharmacokinetic evaluation and fluorescent microscopy. Parameters tested included concentration of paclitaxel, delivery pressure, duration of delivery, and the use of an excipient. In addition, bilateral rabbit iliac arteries were treated with the perfusion catheter and pharmacokinetic evaluation performed at 1 hour, 1 day and 3 days. Benchtop testing demonstrated uniform and circumferential penetration of paclitaxel within the treated arteries. The results of the ex vivo test identified two groups with and without an excipient with similar loading conditions (with excipient: 15.4±8.6 ng/mg vs without excipient: 8.9±6.9 ng/mg, P=.77). The in vivo pharmacokinetic analysis of these two groups demonstrated the use of contrast agent increased arterial paclitaxel levels and maintained initial paclitaxel dosing up to 3 days (With excipient: 1 hour: 107±62 ng vs 3 days: 40±23 ng, P=.824; No excipient: 1 hour: 247±120 ng vs 3 days: 2.92±2.9 ng, P=.009). These results demonstrate the feasibility to deliver paclitaxel directly to the medial layer of an artery via a perfusion catheter. © 2017 John Wiley & Sons Ltd.

  18. Localization of oxidized low-density lipoprotein and its relation to plaque morphology in human coronary artery.

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    Yasumi Uchida

    Full Text Available OBJECTIVES: Oxidized low-density lipoprotein (oxLDL plays a key role in the formation of atherosclerotic plaques. However, its localization in human coronary arterial wall is not well understood. The present study was performed to visualize deposition sites and patterns of native oxLDL and their relation to plaque morphology in human coronary artery. METHODS: Evans blue dye (EB elicits a violet fluorescence by excitation at 345-nm and emission at 420-nm, and a reddish-brown fluorescence by excitation at 470-nm and emission at 515-nm characteristic of oxLDL only. Therefore, native oxLDL in excised human coronary artery were investigated by color fluorescent microscopy (CFM using EB as a biomarker. RESULTS: (1 By luminal surface scan with CFM, the % incidence of oxLDL in 38 normal segments, 41 white plaques and 32 yellow plaques that were classified by conventional angioscopy, was respectively 26, 44 and 94, indicating significantly (p<0.05 higher incidence in the latter than the former two groups. Distribution pattern was classified as patchy, diffuse and web-like. Web-like pattern was observed only in yellow plaques with necrotic core. (2 By transected surface scan, oxLDL deposited within superficial layer in normal segments and diffusely within both superficial and deep layers in white and yellow plaques. In yellow plaques with necrotic core, oxLDL deposited not only in the marginal zone of the necrotic core but also in the fibrous cap. CONCLUSION: Taken into consideration of the well-known process of coronary plaque growth, the results suggest that oxLDL begins to deposit in human coronary artery wall before plaque formation and increasingly deposits with plaque growth, exhibiting different deposition sites and patterns depending on morphological changes.

  19. Particulate suspension Jeffrey fluid flow in a stenosed artery with a particle-free plasma layer near the wall

    Science.gov (United States)

    Ponalagusamy, R.

    2016-08-01

    The present article concerns the problem of blood flow through an artery with an axially asymmetric stenosis (constriction). The two-layered macroscopic model consisting of a cell-rich core of suspension of all the erythrocytes described as a particle-fluid suspension (Jeffrey fluid) and a peripheral zone of cell-free plasma (Newtonian fluid). The analytical expressions for flow characteristics such as fluid phase and particle phase velocities, flow rate, wall shear stress, and resistive force are obtained. It is of interest to mention that the magnitudes of wall shear stress and flow resistance increase with red cell concentration but the flow resistance decreases with increasing shape parameter. One of the important observations is that when blood behaves like a Jeffrey fluid, the flowing blood experiences lesser wall shear stress and flow resistance than in the case of blood being characterized as a Newtonian fluid in both the particle-fluid suspension and particle- free flow studies. The rheology of blood as Jeffrey fluid and the introduction of plasma layer thickness cause significant reduction in the magnitudes of the flow characteristics.

  20. Breast arterial calcification and risk of carotid atherosclerosis: Focusing on the preferentially affected layer of the vessel wall

    Energy Technology Data Exchange (ETDEWEB)

    Sedighi, Nahid, E-mail: nsedighi@sina.tums.ac.ir [Department of Radiology, Shariati Hospital, Tehran University of Medical Sciences. North Kargar Ave., Tehran 14114 (Iran, Islamic Republic of); Radmard, Amir Reza, E-mail: radmard@ams.ac.ir [Department of Radiology, Shariati Hospital, Tehran University of Medical Sciences. North Kargar Ave., Tehran 14114 (Iran, Islamic Republic of); Radmehr, Ali, E-mail: radmehr@sina.tums.ac.ir [Department of Radiology, Shariati Hospital, Tehran University of Medical Sciences. North Kargar Ave., Tehran 14114 (Iran, Islamic Republic of); Hashemi, Pari, E-mail: phtums@yahoo.com [Department of Radiology, Shariati Hospital, Tehran University of Medical Sciences. North Kargar Ave., Tehran 14114 (Iran, Islamic Republic of); Hajizadeh, Abdolmahmoud, E-mail: mroomezi@yahoo.com [Department of Radiology, Shariati Hospital, Tehran University of Medical Sciences. North Kargar Ave., Tehran 14114 (Iran, Islamic Republic of); Taheri, Amir Pejman Hashemi, E-mail: hashemip@sina.tums.ac.ir [Department of Radiology, Shariati Hospital, Tehran University of Medical Sciences. North Kargar Ave., Tehran 14114 (Iran, Islamic Republic of)

    2011-08-15

    Objective: To assess the relationship between breast arterial calcification (BAC) detected on screening mammography and atherosclerosis of carotid arteries considering the most likely involved layer of the arterial wall. Materials and methods: A total of 537 consecutive women who underwent screening mammography were enrolled in this study. Seventy-nine subjects having BAC, aged 46-75 years, and 125 age-matched controls from those without BAC were selected for ultrasound examination of carotid arteries assessing intima-media thickness (IMT) and plaque presence. Participants were divided into three groups of risk including, low-risk: IMT < 0.6 mm without plaque, medium-risk: 0.6 mm {<=} IMT {<=} 0.8 mm without plaque and high-risk: IMT > 0.8 mm and/or plaque. Risk factors for atherosclerosis were obtained from medical records for independent effects. Results: BAC was present in 14.7% of mammograms. According to multivariable logistic regression analyses, significant association was identified between the carotid atherosclerosis risk and presence of BAC. Compared to women with IMT < 0.6 mm, those with 0.6 mm {<=} IMT{<=} 0.8 mm and IMT > 0.8 mm had OR (95% CI) of 4.88 (1.47-16.16) and 23.36 (4.54-120.14), respectively. The OR (95% CI) for carotid plaque was 3.13 (1.3-7.57). There was no interaction between IMT category and plaque. Significant associations were also detected with postmenopausal duration (P = 0.02) and hypertension (P = 0.004). Conclusion: The risk of carotid atherosclerosis increases with the presence of BAC. Women with BAC are more likely to have thicker IMT than plaque, which could be attributed to the preferentially similar affected layer of media causing thick IMT rather than plaque.

  1. Ultrasound characterization of arterial wall structures based on integrated backscatter profiles

    Science.gov (United States)

    Pedersen, Peder C.; Chakareski, Jacob; Lara-Montalvo, Ruben

    2003-05-01

    Studies suggest that the composition of atherosclerotic plaque in the carotid arteries is predictive of stroke risk. The goal of this investigation has been to explore how well the true integrated backscatter (IBS) from plaque regions can be measured non-invasively using ultrasound, based on which plaque composition may be inferred. To obtain the true arterial IBS non-invasively, the scattering and aberrating effect of the intervening tissue layers must be overcome. This is achieved by using the IBS from arterial blood as a reference backscatter, specifically the backscatter from a blood volume along the same scan line as and adjacent to the region of interest. The arterial blood IBS is obtained as an estimated mean of a stochastic process, after clutter removal. We have shown that the variance of the IBS estimate of the blood backscatter signal can be quantified and reduced to a tolerable level. The results are in the form of IBS profiles along the vessel. IBS profiles not normalized with the IBS of the blood-mimicking fluid have been measured for vessels phantom, with and without an intervening inhomogeneous medium; these results are contrasted with the corresponding normalized IBS profiles.

  2. Measurement of arterial wall thickness as a surrogate marker for atherosclerosis

    NARCIS (Netherlands)

    de Groot, E; Hovingh, GK; Wiegman, A; Duriez, P; Smit, AJ; Fruchart, JC; Kastelein, JJP

    2004-01-01

    Large observational studies and atherosclerosis regression trials of lipid-modifying pharmacotherapy have established that intima-media thickness of the carotid and femoral arteries, as measured noninvasively by B-mode ultrasound, is a valid surrogate marker for the progression of atherosclerotic di

  3. VARIATIONS OF MIDDLE SEGMENTAL ARTERY OF HUMAN KIDNEY AND CLINICAL SIGNIFICANCE

    Directory of Open Access Journals (Sweden)

    Gyan Prakash Mishra

    2015-12-01

    Full Text Available Aim: To assess the arterial pattern of middle segmental artery and its relation with collecting system in the human kidneys. Materials and Methods: We studied 50 fresh human Kidneys by corrosion cast techniques. We used different colour coded moulding granules of butyl butyrate, red for artery, blue for vein and black for collecting system of the human kidneys. 20% solution of butyl butyrate in acetone was injected into renal vessels and ureter of each kidney. Injected kidneys were kept immersed in concentrated Potassium Hydroxide solution for corrosion to obtain the endocasts. These endocasts were cleaned under the running tap water and observed macroscopically. Results: We observed three types of variations in arterial pattern of middle segmental artery namely Middle Segmental Artery Type-1 (MSAT1, Middle Segmental Artery Type-2 (MSAT2, Middle Segmental Artery Type-3 (MSAT3 and they were seen in 29(58%, 14(28%, 6(12% kidneys respectively. We also observed three different variations in relation between middle segmental artery and collecting system namely Middle Segmental Artery Group-1 (MSAG1, Middle Segmental Artery Group-2 (MSAG2, Middle Segmental Artery Group-3 (MSAG3 and they were seen in 32%, 24%, 42% kidneys respectively. Conclusion: Anatomical knowledge of these variations is of valuable contribution for uro-surgeon in performing more and more conservative renal surgeries which lead to preservation of healthy and functional renal parenchyma and prevent intraoperative and post-operative complications.

  4. Sphingosine-1-Phosphate Signaling Regulates Myogenic Responsiveness in Human Resistance Arteries.

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    Sonya Hui

    Full Text Available We recently identified sphingosine-1-phosphate (S1P signaling and the cystic fibrosis transmembrane conductance regulator (CFTR as prominent regulators of myogenic responsiveness in rodent resistance arteries. However, since rodent models frequently exhibit limitations with respect to human applicability, translation is necessary to validate the relevance of this signaling network for clinical application. We therefore investigated the significance of these regulatory elements in human mesenteric and skeletal muscle resistance arteries. Mesenteric and skeletal muscle resistance arteries were isolated from patient tissue specimens collected during colonic or cardiac bypass surgery. Pressure myography assessments confirmed endothelial integrity, as well as stable phenylephrine and myogenic responses. Both human mesenteric and skeletal muscle resistance arteries (i express critical S1P signaling elements, (ii constrict in response to S1P and (iii lose myogenic responsiveness following S1P receptor antagonism (JTE013. However, while human mesenteric arteries express CFTR, human skeletal muscle resistance arteries do not express detectable levels of CFTR protein. Consequently, modulating CFTR activity enhances myogenic responsiveness only in human mesenteric resistance arteries. We conclude that human mesenteric and skeletal muscle resistance arteries are a reliable and consistent model for translational studies. We demonstrate that the core elements of an S1P-dependent signaling network translate to human mesenteric resistance arteries. Clear species and vascular bed variations are evident, reinforcing the critical need for further translational study.

  5. CORRELATIONS OF DIFFERENT STRUCTURAL AND FUNCTIONAL CHARACTERISTICS OF ARTERIAL WALL WITH TRADITIONAL CARDIOVASCULAR RISK FACTORS IN HEALTHY PEOPLE OF DIFFERENT AGE. PART 1

    Directory of Open Access Journals (Sweden)

    I. D. Strazhesko

    2016-01-01

    Full Text Available Arterial wall status is determined by several characteristics, the main of them are as follows: pulse wave velocity (PWV, carotid arteries intima-media thickness (IMT, the presence of atherosclerotic plaques, endothelium-dependent vasodilation (EDVD. When these parameters change, the risk for cardiovascular disease (CVD grows. The nature of relationship between these indices in people without CVD clinical signs is understudied, especially in those of older age.Aim. To estimate correlations between different parameters of arterial wall in patients of different age without CVD.Material and methods. A total of 303 people aged 25-91 years without any manifestations of CVD or other chronic diseases and without regular medical treatment were examined. PWV estimation, carotid ultrasound with IMT measurement and atherosclerotic plaques amount calculation and EDVD estimation using reactive hyperemia test were performed. Results. Patients without CVD clinical signs rather often reveal arterial wall lesions already in the younger age group (mean age 40.9±8.7: reduced EDVD – in 26% of the cases, the presence of atherosclerotic plaques – in 22%, increased PWV – in 15%, increased IMT – in 8%. The prevalence of arterial wall alterations in the older age group (mean age 61.19±8.5 increase many-fold. All arterial wall parameters correlate with age. The stronger correlation was revealed between IMT and the amount of atherosclerotic plaques: r=0.46 (р<0.001 in the younger group and r=0.47 (р<0.001 in the older one. We didn’t find any relationship between PWV and EDVD in the younger group and between PWV and the amount of atherosclerotic plaques in the older one. Thickened carotid intima-media increases the risk of arterial stiffness by 2.3 times.Conclusion. Estimation of the state of arterial wall in people of young age without CVD allows detecting individuals who require active CVD prevention. Increased stiffness of arterial wall and the development

  6. STUDY OF PROFUNDA FEMORIS ARTERY OF HUMAN CADAVERS IN RAJKOT CITY, INDIA

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    Pradip R. Chauhan

    2015-03-01

    Full Text Available Background: The profunda femoris artery is the major branch of the femoral artery. It is at critical place in relation to femoral artery for various interventions. Aim: To study the origin of profunda femoris artery. And to compare the cross sectional area of profunda femoris artery between right and left limbs. Material and methods: In this cross sectional study, 51 human femoral triangles from 26 (18 male and 08 female human cadavers in P.D.U. Government Medical College, Rajkot were dissected and studied during regular dissection classes. Site of origin of profunda femoris artery was noted in relation to femoral artery. The distance of origin of profunda femoris artery from the midpoint of inguinal point was measured and noted. Circumference of profunda femoris artery at the level of origin was measured. The cross sectional area was calculated. Collected data was analyzed by standard statistical formulas with the help of Microsoft excel 2007 and Epi info TM 7 software. Result: Most common (52.95% cases site of origin was posterolateral from femoral artery. The mean distance of origin of profunda femoris artery from the midpoint of inguinal ligament was 30.17 mm. There was no significant difference in cross sectional area of right and left profunda femoris artery (at 95% confidence interval Conclusion: Profunda femoris artery is used for angiography, ultrasonography and cardiac catheterization also. It is the major blood supply of the thigh. Its relations with femoral artery, femoral vein and femoral nerve makes it important structure for clinicians. Variations in origin of profunda femoris artery must be considered to avoid complication like aneurism and faulty passage of the catheter. High origin of profunda femoris artery is more prone to damage while accessing femoral artery.

  7. Study of Posterior Cerebral Artery in Human Cadaveric Brain

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    S. A. Gunnal

    2015-01-01

    Full Text Available Objective. Basilar artery (BA terminates in right and left posterior cerebral arteries (PCAs. Each PCA supplies respective occipital lobe of the cerebrum. The present study is designed to know the morphology, morphometry, branching pattern, and symmetry of PCA. Methods. The study included 340 PCAs dissected from 170 human cadaveric brains. Results. Morphological variations of P1 segment included, aplasia (2.35%, hypoplasia (5.29%, duplication (2.35%, fenestration (1.17%, and common trunk shared with SCA (1.76%. Morphological variations of origin of P2 segment included direct origin of it from BA (1.17% and ICA (2.35%. Unusually, two P2 segments, each arising separately from BA and ICA, were observed in 1.17%. Unilateral two P2 segments from CW were found in 0.58%. Morphological variations of course of P2 were duplication (0.58%, fenestration (0.58%, and aneurysm (1.76%. Unilateral P2 either adult or fetal was seen in 4.71%. The group II branching pattern was found to be most common. Asymmetry of P2 was 40%. Morphometry of P2 revealed mean length of 52 mm and mean diameter of 2.7 mm. Conclusion. The present study provides the complete anatomical description of PCA regarding morphology, morphometry, symmetry, and its branching pattern. Awareness of these variations is likely to be useful in cerebrovascular procedures.

  8. Histamine releases PGI2 from human pulmonary artery.

    Science.gov (United States)

    Schellenberg, R R; Duff, M J; Foster, A; Paddon, H B

    1986-08-01

    Histamine caused a triphasic response of human pulmonary artery strips in vitro, consisting of a small initial contraction followed by pronounced relaxation preceding a second contractile response. These characteristics were not seen with other contractile stimuli including 5-hydroxytryptamine, leukotriene D4, and KCl. The relaxant component of this response was ablated by removal of endothelium from the vascular strips or by pretreatment of the tissue with 1 microM indomethacin. Measurement of the PGI2 degradation product 6-keto-PGF1 alpha in supernatants from histamine-challenged tissues confirmed the synthesis of PGI2. Supernatants from unstimulated or leukotriene-challenged tissues contained no detectable amounts of 6-keto-PGF1 alpha. The histamine H1 antagonist diphenydramine inhibited both the contractile and relaxant responses to histamine whereas the H2 antagonist cimetidine affected neither component. The released PGI2 significantly altered the dose-response curve to histamine without inhibiting the maximal contractile responses. We conclude that histamine induces PGI2 formation from pulmonary arterial endothelium via an H1 receptor.

  9. Characterization of human arterial tissue affected by atherosclerosis using multimodal nonlinear optical microscopy

    Science.gov (United States)

    Baria, Enrico; Cicchi, Riccardo; Rotellini, Matteo; Nesi, Gabriella; Massi, Daniela; Pavone, Francesco S.

    2016-03-01

    Atherosclerosis is a widespread cardiovascular disease caused by the deposition of lipids (such as cholesterol and triglycerides) on the inner arterial wall. The rupture of an atherosclerotic plaque, resulting in a thrombus, is one of the leading causes of death in the Western World. Preventive assessment of plaque vulnerability is therefore extremely important and can be performed by studying collagen organization and lipid composition in atherosclerotic arterial tissues. Routinely used diagnostic methods, such as histopathological examination, are limited to morphological analysis of the examined tissues, whereas an exhaustive characterization requires immune-histochemical examination and a morpho-functional approach. Instead, a label-free and non-invasive alternative is provided by nonlinear microscopy. In this study, we combined SHG and FLIM microscopy in order to characterize collagen organization and lipids in human carotid ex vivo tissues affected by atherosclerosis. SHG and TPF images, acquired from different regions within atherosclerotic plaques, were processed through image pattern analysis methods (FFT, GLCM). The resulting information on collagen and cholesterol distribution and anisotropy, combined with collagen and lipids fluorescence lifetime measured from FLIM images, allowed characterization of carotid samples and discrimination of different tissue regions. The presented method can be applied for automated classification of atherosclerotic lesions and plaque vulnerability. Moreover, it lays the foundation for a potential in vivo diagnostic tool to be used in clinical setting.

  10. Computational fluid dynamics comparisons of wall shear stress in patient-specific coronary artery bifurcation using coronary angiography and optical coherence tomography

    Science.gov (United States)

    Poon, Eric; Thondapu, Vikas; Chin, Cheng; Scheerlinck, Cedric; Zahtila, Tony; Mamon, Chris; Nguyen, Wilson; Ooi, Andrew; Barlis, Peter

    2016-11-01

    Blood flow dynamics directly influence biology of the arterial wall, and are closely linked with the development of coronary artery disease. Computational fluid dynamics (CFD) solvers may be employed to analyze the hemodynamic environment in patient-specific reconstructions of coronary arteries. Although coronary X-ray angiography (CA) is the most common medical imaging modality for 3D arterial reconstruction, models reconstructed from CA assume a circular or elliptical cross-sectional area. This limitation can be overcome with a reconstruction technique fusing CA with intravascular optical coherence tomography (OCT). OCT scans the interior of an artery using near-infrared light, achieving a 10-micron resolution and providing unprecedented detail of vessel geometry. We compared 3D coronary artery bifurcation models generated using CA alone versus OCT-angiography fusion. The model reconstructed from CA alone is unable to identify the detailed geometrical variations of diseased arteries, and also under-estimates the cross-sectional vessel area compared to OCT-angiography fusion. CFD was performed in both models under pulsatile flow in order to identify and compare regions of low wall shear stress, a hemodynamic parameter directly linked with progression of atherosclerosis. Supported by ARC LP150100233 and VLSCI VR0210.

  11. Is arterial wall-strain stiffening an additional process responsible for atherosclerosis in coronary bifurcations?: an in vivo study based on dynamic CT and MRI.

    Science.gov (United States)

    Ohayon, Jacques; Gharib, Ahmed M; Garcia, Alberto; Heroux, Julie; Yazdani, Saami K; Malvè, Mauro; Tracqui, Philippe; Martinez, Miguel-Angel; Doblare, Manuel; Finet, Gérard; Pettigrew, Roderic I

    2011-09-01

    Coronary bifurcations represent specific regions of the arterial tree that are susceptible to atherosclerotic lesions. While the effects of vessel compliance, curvature, pulsatile blood flow, and cardiac motion on coronary endothelial shear stress have been widely explored, the effects of myocardial contraction on arterial wall stress/strain (WS/S) and vessel stiffness distributions remain unclear. Local increase of vessel stiffness resulting from wall-strain stiffening phenomenon (a local process due to the nonlinear mechanical properties of the arterial wall) may be critical in the development of atherosclerotic lesions. Therefore, the aim of this study was to quantify WS/S and stiffness in coronary bifurcations and to investigate correlations with plaque sites. Anatomic coronary geometry and cardiac motion were generated based on both computed tomography and MRI examinations of eight patients with minimal coronary disease. Computational structural analyses using the finite element method were subsequently performed, and spatial luminal arterial wall stretch (LW(Stretch)) and stiffness (LW(Stiff)) distributions in the left main coronary bifurcations were calculated. Our results show that all plaque sites were concomitantly subject to high LW(Stretch) and high LW(Stiff), with mean amplitudes of 34.7 ± 1.6% and 442.4 ± 113.0 kPa, respectively. The mean LW(Stiff) amplitude was found slightly greater at the plaque sites on the left main coronary artery (mean value: 482.2 ± 88.1 kPa) compared with those computed on the left anterior descending and left circumflex coronary arteries (416.3 ± 61.5 and 428.7 ± 181.8 kPa, respectively). These findings suggest that local wall stiffness plays a role in the initiation of atherosclerotic lesions.

  12. The influence of artery wall curvature on the anatomical assessment of stenosis severity derived from fractional flow reserve: a computational fluid dynamics study.

    Science.gov (United States)

    Govindaraju, Kalimuthu; Viswanathan, Girish N; Badruddin, Irfan Anjum; Kamangar, Sarfaraz; Salman Ahmed, N J; Al-Rashed, Abdullah A A A

    2016-11-01

    This study aims to investigate the influence of artery wall curvature on the anatomical assessment of stenosis severity and to identify a region of misinterpretation in the assessment of per cent area stenosis (AS) for functionally significant stenosis using fractional flow reserve (FFR) as standard. Five artery models of different per cent AS severity (70, 75, 80, 85 and 90%) were considered. For each per cent AS severity, the angle of curvature of the arterial wall varied from straight to an increasingly curved model (0°, 30°, 60°, 90° and 120°). Computational fluid dynamics was performed under transient physiologic hyperemic flow conditions to investigate the influence of artery wall curvature on the pressure drop and the FFR. The findings in this study may be useful in in vitro anatomical assessment of functionally significant stenosis. The FFR decreased with increasing stenosis severity for a given curvature of the artery wall. Moreover, a significant decrease in FFR was found between straight and curved models discussed for a given severity condition. These findings indicate that the curvature effect was included in the FFR assessment in contrast to minimum lumen area (MLA) or per cent AS assessment. The MLA or per cent AS assessment may lead to underestimation of stenosis severity. From this numerical study, an uncertainty region could be evaluated using the clinical FFR cutoff value of 0.8. This value was observed at 81.98 and 79.10% AS for arteries with curvature angles of 0° and 120° respectively. In conclusion, the curvature of the artery should not be neglected in in vitro anatomical assessment.

  13. Arterialization and anomalous vein wall remodeling in varicose veins is associated with upregulated FoxC2-Dll4 pathway.

    Science.gov (United States)

    Surendran, Sumi; S Ramegowda, Kalpana; Suresh, Aarcha; Binil Raj, S S; Lakkappa, Ravi Kumar B; Kamalapurkar, Giridhar; Radhakrishnan, N; C Kartha, Chandrasekharan

    2016-04-01

    Varicose veins of lower extremities are a heritable common disorder. Mechanisms underlying its pathogenesis are still vague. Structural failures such as valve weakness and wall dilatation in saphenous vein result in venous retrograde flow in lower extremities of body. Reflux of blood leads to distal high venous pressure resulting in distended veins. In an earlier study, we observed a positive association between c.-512C>T FoxC2 gene polymorphism and upregulated FoxC2 expression in varicose vein specimens. FoxC2 overexpression in vitro in venous endothelial cells resulted in the elevated mRNA expression of arterial endothelial markers such as Delta-like ligand 4 (Dll4) and Hairy/enhancer-of-split related with YRPW motif protein 2 (Hey2). We hypothesized that an altered FoxC2-Dll4 signaling underlies saphenous vein wall remodeling in patients with varicose veins. Saphenous veins specimens were collected from 22 patients with varicose veins and 20 control subjects who underwent coronary artery bypass grafting. Tissues were processed for paraffin embedding and sections were immunostained for Dll4, Hey2, EphrinB2, α-SMA, Vimentin, and CD31 antigens and examined under microscope. These observations were confirmed by quantitative real-time PCR and western blot analysis. An examination of varicose vein tissue specimens by immunohistochemistry indicated an elevated expression of Notch pathway components, such as Dll4, Hey2, and EphrinB2, and smooth muscle markers, which was further confirmed by gene and protein expression analyses. We conclude that the molecular alterations in Dll4-Hey2 signaling are associated with smooth muscle cell hypertrophy and hyperplasia in varicose veins. Our observations substantiate a significant role for altered FoxC2-Dll4 signaling in structural alterations of saphenous veins in patients with varicose veins.

  14. Pharmacological modulation of arterial stiffness.

    LENUS (Irish Health Repository)

    Boutouyrie, Pierre

    2011-09-10

    Arterial stiffness has emerged as an important marker of cardiovascular risk in various populations and reflects the cumulative effect of cardiovascular risk factors on large arteries, which in turn is modulated by genetic background. Arterial stiffness is determined by the composition of the arterial wall and the arrangement of these components, and can be studied in humans non-invasively. Age and distending pressure are two major factors influencing large artery stiffness. Change in arterial stiffness with drugs is an important endpoint in clinical trials, although evidence for arterial stiffness as a therapeutic target still needs to be confirmed. Drugs that independently affect arterial stiffness include antihypertensive drugs, mostly blockers of the renin-angiotensin-aldosterone system, hormone replacement therapy and some antidiabetic drugs such as glitazones. While the quest continues for \\'de-stiffening drugs\\

  15. wall

    Directory of Open Access Journals (Sweden)

    Irshad Kashif

    2016-01-01

    Full Text Available Maintaining indoor climatic conditions of buildings compatible with the occupant comfort by consuming minimum energy, especially in a tropical climate becomes a challenging problem for researchers. This paper aims to investigate this problem by evaluating the effect of different kind of Photovoltaic Trombe wall system (PV-TW on thermal comfort, energy consumption and CO2 emission. A detailed simulation model of a single room building integrated with PV-TW was modelled using TRNSYS software. Results show that 14-35% PMV index and 26-38% PPD index reduces as system shifted from SPV-TW to DGPV-TW as compared to normal buildings. Thermal comfort indexes (PMV and PPD lie in the recommended range of ASHARE for both DPV-TW and DGPV-TW except for the few months when RH%, solar radiation intensity and ambient temperature were high. Moreover PVTW system significantly reduces energy consumption and CO2 emission of the building and also 2-4.8 °C of temperature differences between indoor and outdoor climate of building was examined.

  16. Genetic susceptibility of the arterial wall is an important determinant of atherosclerosis in C57BL/6 and FVB/N mouse strains

    DEFF Research Database (Denmark)

    Shim, Jeong; Handberg, Aase; Östergren, Eva-Britt Caroline

    2011-01-01

    How genetic variations among inbred mouse strains translate into differences in atherosclerosis susceptibility is of significant interest for the development of new therapeutic strategies. The objective of the present study was to examine whether genetically controlled arterial wall properties in...... influence atherosclerosis susceptibility in FVB/N (FVB) and C57BL/6 (B6) apolipoprotein E knockout (apoE(-/-)) mouse strains....

  17. Prevalence and Risk Factors of Carotid Vessel Wall Inflammation in Coronary Artery Disease Patients FDG-PET and CT Imaging Study

    NARCIS (Netherlands)

    J. Bucerius; R. Duivenvoorden; V. Mani; C. Moncrieff; J.H.F. Rudd; C. Calcagno; J. Machac; V. Fuster; M.E. Farkouh; Z.A. Fayad

    2011-01-01

    OBJECTIVES We investigated the prevalence and clinical risk factors of carotid vessel wall inflammation by means of (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) in a population consisting of coronary artery disease (CAD) patients. BACKGROUND The atherosclerotic disease process is

  18. Measurement of the ultrasonic properties of human coronary arteries in vitro with a 50-MHz acoustic microscope

    Directory of Open Access Journals (Sweden)

    Machado J.C.

    2002-01-01

    Full Text Available Ultrasonic attenuation coefficient, wave propagation speed and integrated backscatter coefficient (IBC of human coronary arteries were measured in vitro over the -6 dB frequency bandwidth (36 to 67 MHz of a focused ultrasound transducer (50 MHz, focal distance 5.7 mm, f/number 1.7. Corrections were made for diffraction effects. Normal and diseased coronary artery sub-samples (N = 38 were obtained from 10 individuals at autopsy. The measured mean ± SD of the wave speed (average over the entire vessel wall thickness was 1581.04 ± 53.88 m/s. At 50 MHz, the average attenuation coefficient was 4.99 ± 1.33 dB/mm with a frequency dependence term of 1.55 ± 0.18 determined over the 36- to 67-MHz frequency range. The IBC values were: 17.42 ± 13.02 (sr.m-1 for thickened intima, 11.35 ± 6.54 (sr.m-1 for fibrotic intima, 39.93 ± 50.95 (sr.m-1 for plaque, 4.26 ± 2.34 (sr.m-1 for foam cells, 5.12 ± 5.85 (sr.m-1 for media and 21.26 ± 31.77 (sr.m-1 for adventitia layers. The IBC results indicate the possibility for ultrasound characterization of human coronary artery wall tissue layer, including the situations of diseased arteries with the presence of thickened intima, fibrotic intima and plaque. The mean IBC normalized with respect to the mean IBC of the media layer seems promising for use as a parameter to differentiate a plaque or a thickened intima from a fibrotic intima.

  19. Children and Adolescent Obesity Associates with Pressure-Dependent and Age-Related Increase in Carotid and Femoral Arteries’ Stiffness and Not in Brachial Artery, Indicative of Nonintrinsic Arterial Wall Alteration

    Directory of Open Access Journals (Sweden)

    Victoria García-Espinosa

    2016-01-01

    Full Text Available Aim. To analyze if childhood obesity associates with changes in elastic, transitional, and/or muscular arteries’ stiffness. Methods. 221 subjects (4–15 years, 92 females were assigned to normal weight (NW, n=137 or obesity (OB, n=84 groups, considering their body mass index z-score. Age groups were defined: 4–8; 8–12; 12–15 years old. Carotid, femoral, and brachial artery local stiffness was determined through systodiastolic pressure-diameter and stress-strain relationships. To this end, arterial diameter and peripheral and aortic blood pressure (BP levels and waveforms were recorded. Carotid-femoral, femoropedal, and carotid-radial pulse wave velocities were determined to evaluate aortic, lower-limb, and upper-limb regional arterial stiffness, respectively. Correlation analysis between stiffness parameters and BP was done. Results. Compared to NW, OB subjects showed higher peripheral and central BP and carotid and femoral stiffness, reaching statistical significance in subjects aged 12 and older. Arterial stiffness differences disappeared when levels were normalized for BP. There were no differences in intrinsic arterial wall stiffness (elastic modulus, BP stiffness relationships, and regional stiffness parameters. Conclusion. OB associates with BP-dependent and age-related increase in carotid and femoral (but not brachial stiffness. Stiffness changes would not be explained by intrinsic arterial wall alterations but could be associated with the higher BP levels observed in obese children.

  20. Potential for tissue characterization of plaque and arterial wall using intravascular ultrasound

    Science.gov (United States)

    Sudhir, Krishnakutty; Fitzgerald, Peter J.; Yock, Paul G.

    1993-09-01

    Current intravascular ultrasound imaging technology is able to determine the extent and distribution of pathologic processes within the vessel wall, but is not highly sensitive in discriminating between different types of pathologic tissue. `Tissue characterization' refers to a set of computer-based techniques that utilize features of the ultrasound signal beyond basic amplitude to help define the structure of the tissue of interest. Although preliminary results with this approach are encouraging, additional work is needed to define its clinical application in vascular disease.

  1. Assessment of influence of traditional cardiovascular risk factors and inflammation on arterial wall structural characteristics in psoriatic arthritis

    Directory of Open Access Journals (Sweden)

    T V Korotaeva

    2009-01-01

    Full Text Available Assessment of influence of traditional cardiovascular risk factors and inflammation on arterial wall structural characteristics in psoriatic arthritis. Objective. To assess possibility of traditional cardiovascular risk (CVR factors application as markers of subclinical atherosclerosis in pts with psoriatic arthritis (PA. Material and methods. 130 pts with PA (51 male and 79 female without clinical signs of coronary heart disease (CHD and stroke. were included. Mean age was 43 years (39-48 years, mean PA duration – 7 years (2 months-42 years, mean psoriasis duration – 15 years (5,5 – 26 years. PA activity was assessed with DAS4. Age, total cholesterol (TC, high density lipoprotein (HDLP, low density lipoprotein (LDLP, C-reactive protein (CRP, fibrinogen, systolic blood pressure, body mass index (BMI, atherogenity coefficient (AC, relative risk of CHD development, presence of diabetes and smoking were evaluated. Mean and maximal intima-media complex thickness (IMCT of common carotid arteries was examined with duplex scanning. Results. TC, LDLP and AC elevation was revealed in all and BMI elevation – in one third of pts. In 55% of pts CVR was mean and higher, in 23,5% CVR was absent and in 21,5% CVR was below mean. CVR significantly correlated with mean and maximal carotid arteries IMCT (R=0,48, p<0,00001 and R=0,41, p<0,00001 and fibrinogen (R=0,22, p<0,011. In women CVR correlated with fibrinogen (R=0,27, p<0,16, BMI (R=0,35, p<0,16, mean and maximal carotid arteries IMCT (R=0,50, p<0,00001 and R=0,38, p<0,0005 respectively and psoriasis duration (R=0,30, p<0,006. In men CVR did not correlated with fibrinogen. CVR did not correlated with DAS4 and CRP. Conclusion. CVR in PA is not connected with traditional markers of inflammation andindex of clinical disease activity.

  2. A STUDY OF ARTERIAL SUPPLY OF VERMIFORM APPENDIX IN HUMANS

    Directory of Open Access Journals (Sweden)

    Hosmani

    2012-11-01

    Full Text Available ABSTRACT: The surgical procedures like appendicectomy, demands a precise knowledge of vascular anatomy of ileocolic region. The aim of th is study is to study the arterial supply of the appendix, findings of which may reveal more anatomica l facts about the arteries of appendix and their variations. Total 52 specimens of caecum a nd appendix with their arteries intact were collected, cleaned and dissected. The ileocolic art ery and its branches to the appendix were traced carefully and observations were recorded. Th e ileocolic artery arises independently from superior mesenteric artery in 96.88% of cases and en ds by dividing into superior and inferior division in 93.76% of cases. The appendicular artery arises from inferior division in 46.88%, ileal branch 28.13%, ileocolic artery 18.75% and fr om arterial arcade in 6.25% of cases. 21.87% of cases showed additional appendicular artery. KEYWORDS: Caecum, appendix, ileocolic artery, appendicular arter y.

  3. Factors influencing the diameter of human anterior and posterior intercostal arteries.

    Science.gov (United States)

    Kuhlman, David R; Khuder, Sadik A; Lane, Richard D

    2015-03-01

    At present, there have not been any detailed studies examining the size relationships of the intercostal arteries. This study was carried out to investigate the relationship between the vessel lumenal diameter of ipsilateral, paired anterior and posterior IC arteries, as well as with the length of the IC space supplied by each artery. Samples were collected from the second-sixth anterior and posterior IC arteries near their site of origin, and the lengths of the corresponding IC spaces were measured in 42 cadavers. Lumenal diameters of both the anterior and posterior IC arteries at consecutive IC space closely followed second degree polynomial regression models (R(2) = 0.9655, and R(2) = 0.9741, respectively), and reached maximum size at the fifth IC space, which was found to be the longest of the IC spaces. No direct relationship was observed between diameters of the paired anterior and posterior IC arteries, although there was a trend for the larger anterior IC arteries to be paired with the larger posterior IC arteries. The calculated rate of blood flow at each IC artery was approximately two-fold greater in males than in females. These results suggest that the length of the IC space, and hence the extent of the thoracic wall supplied, is a major factor in determining the diameter of both anterior and posterior IC arteries. Since COPD is such a prevalent disease, this study also examined its influence on the IC arteries, and found that the posterior IC arteries are significantly larger among afflicted subjects. © 2014 Wiley Periodicals, Inc.

  4. Assessment of pulsatile wall shear stress in compliant arteries: numerical model, validation and experimental data.

    Science.gov (United States)

    Salvucci, Fernando P; Perazzo, Carlos A; Barra, Juan G; Armentano, Ricardo L

    2009-01-01

    There is evidence that wall shear stress (WSS) is associated with vascular disease. In particular, it is widely accepted that vascular segments with low or oscillatory values of WSS are more probable to develop vascular disease. It is then necessary to establish a realistic model of the blood flow in blood vessels in order to determine precisely WSS. We proposed a numerical 1D model which takes into account the pulsatile nature of blood flow, the elasticity of the vessel, and its geometry. The model allows the calculation of shear stress. It was validated for stationary situations. Then, we computed the time-dependent WSS distribution from experimental data in the sheep thoracic aorta. Results showed that mean WSS calculated through steady flow and rigid walls models is overestimated. Peak WSS values for pulsatile flow must be considered since they resulted to be at least one order higher than mean values. Oscillations in shear stress in a period showed to be approximately of 40%. These findings show that the proposed model is suitable for estimating time-dependent WSS distributions, and confirm the need of using this kind of model when trying to evaluate realistic WSS in blood vessels.

  5. Velocity profile and wall shear stress of saccular aneurysms at the anterior communicating artery.

    Science.gov (United States)

    Yamaguchi, Ryuhei; Ujiie, Hiroshi; Haida, Sayaka; Nakazawa, Nobuhiko; Hori, Tomokatsu

    2008-01-01

    It has recently been shown that the aspect ratio (dome/neck) of an aneurysm correlates well with intraaneurysmal blood flow. Aneurysms with an aspect ratio larger than 1.6 carry a higher risk of rupture. We examined the effect of aspect ratio (AR) on intra-aneurysmal flow using experimental models. Flow visualization with particle imaging velocimetry and measurement of wall shear stress using laser Doppler anemometry were performed on three different aneurysm models: AR 0.5, 1.0, and 2.0. Intraaneurysmal flow consists of inflow, circulation, and outflow. Rapid inflow impinged on the distal neck creating a stagnant point. Rapid flow and maximum wall shear stress were observed in the vicinity of the stagnant point. By changing the Reynold's number, the stagnant point moved. By increasing the AR of the aneurysm, vortices inside the aneurysm sac closed and very slow flow was observed, resulting in very low shear stress markedly at a Reynold's number of 250, compatible with the diastolic phase. In the aneurysm model AR 2.0, both rapid flow at the neck and vortices inside the aneurysm are sufficient to activate platelets, making a thrombus that may anchor on the dome where very slow flow takes place. Hemodynamics in aneurysms larger than AR 2.0 definitely contribute to thrombus formation.

  6. Imaging and modeling of acute pressure-induced changes of collagen and elastin microarchitectures in pig and human resistance arteries

    DEFF Research Database (Denmark)

    Bloksgaard, Maria; Leurgans, Thomas M; Spronck, Bart

    2017-01-01

    The impact of disease related changes in the extracellular matrix (ECM) on the mechanical properties of human resistance arteries largely remains to be established. Resistance arteries from both pig and human parietal pericardium (PRA) display a different ECM microarchitecture compared to frequen......The impact of disease related changes in the extracellular matrix (ECM) on the mechanical properties of human resistance arteries largely remains to be established. Resistance arteries from both pig and human parietal pericardium (PRA) display a different ECM microarchitecture compared...

  7. The Fatty Acid Composition of Blood Plasma and Arterial Wall in Atherosclerosis

    Directory of Open Access Journals (Sweden)

    Alexander N. Osipenko

    2012-12-01

    Full Text Available The aim of this study was to assess the fatty acid balance in the blood plasma, in the fragments of the intact vessels and the vessels showing signs of atherosclerosis.Material and Methods: The article presents the results of the examination of the blood plasma samples of patients with coronary heart disease and coronary atherosclerosis. The control group consisted of 16 healthy individuals. Also, the fragments of the abdominal aorta and the common carotid artery with varying degrees of atherosclerotic lesions were studied. Fatty acid analysis was conducted using capillary gas-liquid chromatography. Results: A reduction in the relative linoleic acid level with an increase in almost all the saturated fatty acids and polyunsaturated dihomo-γ-linolenic acid in the plasma was noted in patients with coronary heart disease and atherosclerosis. The relationships between certain fatty acids in patients with atherosclerosis and myocardial ischemia showed changes. In patients with atherosclerosis, a marked imbalance was observed between the monounsaturated and correspondingly the saturated fatty acids (with the same number of carbon atoms in the abdominal aorta with significant atherosclerotic lesions, as well as in the intact common carotid arteries. These disorders are probably related to the relatively low content of the linoleic acid in the blood plasma. The reasons for the increased activity of the fatty acid synthase in vessels with significant atherosclerotic lesions are described. It is concluded that most of the fatty acids of the plaque were formed due to the synthetic processes in the smooth muscle cells, and not as a result of their intake from the blood plasma.

  8. Bestrophin-3 associated Ca2+-activated Cl- conductance is important for synchronization in the arterial wall

    DEFF Research Database (Denmark)

    Brøgger, Torbjørn; Aalkjær, Christian; Matchkov, Vladimir

    2009-01-01

    of bestrophin proteins family - Best-3. We have aimed here to explore the importance of Best-3 for vascular wall function.   Segments of the mesenteric small arteries were transfected in vivo in anaesthetized rats with siRNA against Best-3 and siRNA with mismatching nucleotides (mutated siRNA) as a control....... The efficiency of transfection at molecular level was evaluated 3 days after transfection. Contractility, vasomotion and [Ca2+]i dynamic were tested in isometric myograph and using confocal microscope.   The specific Best-3 siRNA significantly reduced Best-3 expression in comparison to the control. Arteries from......-cGMP to the endothelium-denuded vessels restored vasomotion but did not change the difference between groups. SMCs in control endothelium-intact arteries were completely synchronized whereas in the siRNA-transfected arteries only partial synchronization was observed.   Our data suggest that the Best-3-associated Ic...

  9. Compliant model of a coupled sequential coronary arterial bypass graft: effects of vessel wall elasticity and non-Newtonian rheology on blood flow regime and hemodynamic parameters distribution.

    Science.gov (United States)

    Kabinejadian, Foad; Ghista, Dhanjoo N

    2012-09-01

    We have recently developed a novel design for coronary arterial bypass surgical grafting, consisting of coupled sequential side-to-side and end-to-side anastomoses. This design has been shown to have beneficial blood flow patterns and wall shear stress distributions which may improve the patency of the CABG, as compared to the conventional end-to-side anastomosis. In our preliminary computational simulation of blood flow of this coupled sequential anastomoses design, the graft and the artery were adopted to be rigid vessels and the blood was assumed to be a Newtonian fluid. Therefore, the present study has been carried out in order to (i) investigate the effects of wall compliance and non-Newtonian rheology on the local flow field and hemodynamic parameters distribution, and (ii) verify the advantages of the CABG coupled sequential anastomoses design over the conventional end-to-side configuration in a more realistic bio-mechanical condition. For this purpose, a two-way fluid-structure interaction analysis has been carried out. A finite volume method is applied to solve the three-dimensional, time-dependent, laminar flow of the incompressible, non-Newtonian fluid; the vessel wall is modeled as a linearly elastic, geometrically non-linear shell structure. In an iteratively coupled approach the transient shell equations and the governing fluid equations are solved numerically. The simulation results indicate a diameter variation ratio of up to 4% and 5% in the graft and the coronary artery, respectively. The velocity patterns and qualitative distribution of wall shear stress parameters in the distensible model do not change significantly compared to the rigid-wall model, despite quite large side-wall deformations in the anastomotic regions. However, less flow separation and reversed flow is observed in the distensible models. The wall compliance reduces the time-averaged wall shear stress up to 32% (on the heel of the conventional end-to-side model) and somewhat

  10. Differential response of human fetal smooth muscle cells from arterial duct to retinoid acid

    Institute of Scientific and Technical Information of China (English)

    Li-hui WU; Shao-jun XU; Jian-ying TENG; Wei WU; Du-yun YE; Xing-zhong WU

    2008-01-01

    Aim:The aim of the present study was to understand the role of retinoic acid (RA) in the development of isolated patent ductus arteriosus and the features of arterial duct-derived vascular smooth muscle cells (VSMC). Methods:The VSMC were isolated, and the biological characteristics and the response to RA were investi-gated in the arterial duct, aorta, and pulmonary artery VSMC from 6 human embry-onic samples. Western blotting, immunostaining, and cell-based ELISA were em-ployed to analyze the proliferation regulation of VSMC. Results:The VSMC from the arterial duct expressed proliferating cell nuclear antigen (PCNA) at a signifi-cantly lower rate than those from the aorta and pulmonary artery, but expressed a higher level of Bax and Bcl-2. The expression level of PCNA or Bcl-2 was associ-ated with the embryonic age. The effects of RA on the VSMC from the arterial duct were quite different from those from the aorta and pulmonary artery. In arterial duct VSMC, RA stimulated PCNA expression, but such stimulation could be sup-pressed by CD2366, an antagonist of nuclear retinoid receptor activation. In aorta or pulmonary artery VSMC, the expression response of PCNA to RA was insignificant. The ratio of Bax/Bcl-2 decreased in arterial duct VSMC after RA treatment due to the significant inhibition of Bax expression. Conclusion:The VSMC from the arterial duct possessed distinct biological behaviors. RA might be important in the development of ductus arteriosus VSMC.

  11. Comparison of cardiovascular magnetic resonance of late gadolinium enhancement and diastolic wall thickness to predict recovery of left ventricular function after coronary artery bypass surgery

    Directory of Open Access Journals (Sweden)

    Udompunturak Suthipol

    2008-09-01

    Full Text Available Abstract Background The objective was to compare the value of late gadolinium enhancement (LGE and end-diastolic wall thickness (EDWT assessed by cardiovascular magnetic resonance (CMR in predicting recovery of left ventricular function after coronary artery bypass surgery (CABG. Methods We enrolled patients with coronary artery disease and left ventricular ejection fraction Results We studied 46 men and 4 women with an average age of 61 years. Baseline left ventricular ejection fraction was 37 ± 13%. A total of 2,020 myocardial segments were analyzed. Abnormal wall motion and the LGE area were detected in 1,446 segments (71.6% and 1,196 segments (59.2% respectively. Wall motion improvement was demonstrated in 481 of 1,227 segments (39.2% that initially had wall motion abnormalities at baseline. Logistic regression analysis showed that the LGE area, EDWT and resting wall motion grade predicted wall motion improvement. Comparison of Receiver-Operator-Characteristic (ROC curves demonstrated that the LGE area was the most important predictor (p Conclusion LGE and EDWT are independent predictors for functional recovery after revascularization. However, LGE appears to be a more important factor and independent of EDWT.

  12. The subpetrous carotid wall hematoma. A sign of spontaneous dissection of the internal carotid artery on non-enhanced computed tomography. A retrospective study

    Energy Technology Data Exchange (ETDEWEB)

    Jensen-Kondering, U. [Univ. Hospital Schleswig-Holstein, Kiel (Germany). Dept. of Radiology and Neuroradiology; Univ. Hospital Schleswig-Holstein, Kiel (Germany). Dept. of Neurology; Huhndorf, M.; Madjidyar, J.; Jansen, O. [Univ. Hospital Schleswig-Holstein, Kiel (Germany). Dept. of Radiology and Neuroradiology

    2015-03-15

    Spontaneous dissection of the internal carotid artery (CAD) is an increasingly recognized cause for stroke especially in young and middle-aged patients. We hypothesized that non-enhanced cranial computed tomography (NECCT) can visualize the subpetrous carotid wall hematoma and thus enable identification of patients with CAD. We retrospectively reviewed patients with confirmed CAD (n=21) and a control group with ischemic symptoms but without CAD (n=42) who received NECCT at admission. Two independent neuroradiologists rated the presence and shape of SPH, density and diameter of the subpetrous internal carotid artery. Additionally, we correlated the shape of the subpetrous carotid wall hematoma with the grade of stenosis on subsequent angiographic imaging. The subpetrous carotid wall hematoma was present in 14 of 21 patients (Cohen's k = 0.67). Mean diameter was 6.95 ± 1.05 mm in dissected vessels and 5.71 ± 1.52 mm in the contralateral vessel (p<0.05). Mean difference in vessel density was 15.05 ± 8.01 HU (p<0.01). Median grade of stenosis was significantly higher in patients with a full moon- shaped (n=11) than crescent-shaped (n=3) subpetrous carotid wall hematoma (21% vs. 80%, p<0.05). Two-thirds of patients with CAD were correctly identified on NECCT. The extracranial carotid artery should be evaluated in patients with symptoms of cerebral ischemia.

  13. Reduced arterial diameter during static exercise in humans

    DEFF Research Database (Denmark)

    Olesen, H L; Mitchell, J H; Friedman, D B

    1995-01-01

    of another limb. Static exercise increased heart rate and mean arterial pressure, which were largest during one-leg knee extension. After exercise heart rate and mean arterial pressure returned to the resting level. No changes were recorded in arterial carbon dioxide tension, and the rate of perceived......In eight subjects luminal diameter of the resting limb radial and dorsalis pedis arteries was determined by high-resolution ultrasound (20 MHz). This measurement was followed during rest and during 2 min of static handgrip or of one-leg knee extension at 30% of maximal voluntary contraction...... exertion was approximately 15 units after both types of exercise. The dorsalis pedis arterial diameter was 1.50 +/- 0.20 mm (mean and SE) and the radial AD 2.45 +/- 0.12 mm. During both types of contractions the luminal diameters decreased approximately 3.5% within the first 30 s (P

  14. Structural alterations of the coronary arterial wall are associated with myocardial flow heterogeneity in type 2 diabetes mellitus

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, Thomas H. [California Univ., Los Angeles, CA (United States). Dept. of Moelecular and Medical Pharmacology, Radiological Science]|[University Hospital of Geneva, Department of Internal Medicine, Cardiovascular Center, Nuclear Cardiology, Geneva (Switzerland); Facta, Alvaro D.; Prior, John O.; Cadenas, Jerson; Zhang, Xiao-Li; Sayre, James; Goldin, Jonathan; Schelbert, Heinrich R. [California Univ., Los Angeles, CA (United States). Dept. of Moelecular and Medical Pharmacology, Radiological Science; Li, Yanjie [University of Southern California, Atherosclerosis Research Unit, Keck School of Medicine, Los Angeles, CA (United States)

    2009-02-15

    To determine the relationship between carotid intima-media thickness (IMT), coronary artery calcification (CAC), and myocardial blood flow (MBF) at rest and during vasomotor stress in type 2 diabetes mellitus (DM). In 68 individuals, carotid IMT was measured using high-resolution vascular ultrasound, while the presence of CAC was determined with electron beam tomography (EBT). Global and regional MBF was determined in milliliters per gram per minute with {sup 13}N-ammonia and positron emission tomography (PET) at rest, during cold pressor testing (CPT), and during adenosine (ADO) stimulation. There was neither a relationship between carotid IMT and CAC (r = 0.10, p = 0.32) nor between carotid IMT and coronary circulatory function in response to CPT and during ADO (r = -0.18, p = 0.25 and r = 0.10, p = 0.54, respectively). In 33 individuals, EBT detected CAC with a mean Agatston-derived calcium score of 44 {+-} 18. There was a significant difference in regional MBFs between territories with and without CAC at rest and during ADO-stimulated hyperemia (0.69 {+-} 0.24 vs. 0.74 {+-} 0.23 and 1.82 {+-} 0.50 vs. 1.95 {+-} 0.51 ml/g/min; p {<=} 0.05, respectively) and also during CPT in DM but less pronounced (0.81 {+-} 0.24 vs. 0.83 {+-} 0.23 ml/g/min; p = ns). The increase in CAC was paralleled with a progressive regional decrease in resting as well as in CPT- and ADO-related MBFs (r = -0.36, p {<=} 0.014; r = -0.46, p {<=} 0.007; and r = -0.33, p {<=} 0.041, respectively). The absence of any correlation between carotid IMT and coronary circulatory function in type 2 DM suggests different features and stages of early atherosclerosis in the peripheral and coronary circulation. PET-measured MBF heterogeneity at rest and during vasomotor stress may reflect downstream fluid dynamic effects of coronary artery disease (CAD)-related early structural alterations of the arterial wall. (orig.)

  15. MRI-determined carotid artery flow velocities and wall shear stress in a mouse model of vulnerable and stable atherosclerotic plaque.

    Science.gov (United States)

    van Bochove, Glenda S; Straathof, Roel; Krams, Rob; Nicolay, Klaas; Strijkers, Gustav J

    2010-04-01

    We report here on the pre-clinical MRI characterization of an apoE-/- mouse model of stable and vulnerable carotid artery atherosclerotic plaques, which were induced by a tapered restriction (cast) around the artery. Specific focus was on the quantification of the wall shear stress, which is considered a key player in the development of the plaque phenotype. In vivo MRI was performed at 9.4 T. The protocol consisted of time-of-flight angiography, high-resolution T1- and T2-weighted black-blood imaging and phase-contrast flow velocity imaging as function of time in the cardiac cycle. Wall shear stress was determined by fitting the flow profile to a quadratic polynomial. Time-of-flight angiography confirmed preservation of blood flow through the carotid arteries in all cases. T1- and T2-weighted MRI resulted in high-resolution images in which the position of the cast, luminal narrowing introduced by cast and plaque, as well as the arterial wall could be well identified. Laminar flow with low wall shear stress (11.2+/- 5.2 Pa) was measured upstream to the cast at the position of the vulnerable plaque. Downstream to the cast at the position of the stable plaque, the apparent velocities were low, which is consistent with vortices and an oscillatory nature of the flow. Flow velocities and wall shear stress were successfully measured in this mouse model of stable and unstable plaque. The presented tools can be used to provide valuable insights in the pathogenesis of atherosclerosis.

  16. Heterogeneity and weak coupling may explain the synchronization characteristics of cells in the arterial wall.

    Science.gov (United States)

    Jacobsen, Jens Christian Brings; Aalkjaer, Christian; Matchkov, Vladimir V; Nilsson, Holger; Freiberg, Jacob J; Holstein-Rathlou, Niels-Henrik

    2008-10-13

    Vascular smooth muscle cells (SMCs) exhibit different types of calcium dynamics. Static vascular tone is associated with unsynchronized calcium waves and the developed force depends on the number of recruited cells. Global calcium transients synchronized among a large number of cells cause rhythmic development of force known as vasomotion. We present experimental data showing a considerable heterogeneity in cellular calcium dynamics in the vascular wall. In stimulated vessels, some SMCs remain quiescent, whereas others display waves of variable frequency. At the onset of vasomotion, all SMCs are enrolled into synchronized oscillation. Simulations of coupled SMCs show that the experimentally observed cellular recruitment, the presence of quiescent cells and the variation in oscillation frequency may arise if the cell population is phenotypically heterogeneous. In this case, quiescent cells can be entrained at the onset of vasomotion by the collective driving force from the synchronized oscillations in the membrane potential of the surrounding cells. Partial synchronization arises with an increase in the concentration of cyclic guanosine monophosphate, but in a heterogeneous cell population complete synchronization also requires a high-conductance pathway that provides strong coupling between the cells.

  17. The Effect of Hypertension on the Transport of LDL Across the Deformable Arterial Wall

    Science.gov (United States)

    Dabagh, Mahsa; Jalali, Payman

    2010-05-01

    The influences of increased endothelial cell turnover and deformation of the intima on the transport of low-density lipoprotein (LDL) under hypertension are investigated by applying a multilayered model of aortic wall. The thickness and properties of the endothelium, intima, internal elastic lamina (IEL), and media are affected by the transmural pressure. Navier-Stokes and Brinkman equations are applied for the transport of the transmural flow and the convective-diffusion equation is solved for LDL transport. LDL macromolecules enter the intima through leaky junctions, and then pass through the media layer where they permeate over the surface of smooth muscle cells (SMC). Uptake of LDL by cells is modeled through a uniform reaction evenly distributed in the macroscopically homogeneous media layer. The results show that transmural pressure significantly affects the LDL fluxes across the leaky junction, the intima, fenestral pores in the IEL, and the media layer. Many realistic predictions including the proper magnitudes for the permeability of endothelium and intimal layers, and the hydraulic conductivity of all layers as well as their trends with pressure are predicted by the present model.

  18. Algorithm for quantifying advanced carotid artery atherosclerosis in humans using MRI and active contours

    Science.gov (United States)

    Adams, Gareth; Vick, G. W., III; Bordelon, Cassius; Insull, William; Morrisett, Joel

    2002-05-01

    A new algorithm for measuring carotid artery volumes and estimating atherosclerotic plaque volumes from MRI images has been developed and validated using pressure-perfusion-fixed cadaveric carotid arteries. Our method uses an active contour algorithm with the generalized gradient vector field force as the external force to localize the boundaries of the artery on each MRI cross-section. Plaque volume is estimated by an automated algorithm based on estimating the normal wall thickness for each branch of the carotid. Triplicate volume measurements were performed by a single observer on thirty-eight pairs of cadaveric carotid arteries. The coefficient of variance (COV) was used to quantify measurement reproducibility. Aggregate volumes were computed for nine contiguous slices bounding the carotid bifurcation. The median (mean +/- SD) COV for the 76 aggregate arterial volumes was 0.93% (1.47% +/- 1.52%) for the lumen volume, 0.95% (1.06% +/- 0.67%) for the total artery volume, and 4.69% (5.39% +/- 3.97%) for the plaque volume. These results indicate that our algorithm provides repeatable measures of arterial volumes and a repeatable estimate of plaque volume of cadaveric carotid specimens through analysis of MRI images. The algorithm also significantly decreases the amount of time necessary to generate these measurements.

  19. Pharmacological characterization of VIP and PACAP receptors in the human meningeal and coronary artery

    DEFF Research Database (Denmark)

    Chan, Kayi Y; Baun, Michael; de Vries, René;

    2011-01-01

    We pharmacologically characterized pituitary adenylate cyclase-activating polypeptides (PACAPs), vasoactive intestinal peptide (VIP) and the VPAC(1), VPAC(2) and PAC(1) receptors in human meningeal (for their role in migraine) and coronary (for potential side effects) arteries....

  20. Pharmacological characterization of VIP and PACAP receptors in the human meningeal and coronary artery

    DEFF Research Database (Denmark)

    Chan, Kayi Y; Baun, Michael; de Vries, René;

    2011-01-01

    We pharmacologically characterized pituitary adenylate cyclase-activating polypeptides (PACAPs), vasoactive intestinal peptide (VIP) and the VPAC(1), VPAC(2) and PAC(1) receptors in human meningeal (for their role in migraine) and coronary (for potential side effects) arteries.......We pharmacologically characterized pituitary adenylate cyclase-activating polypeptides (PACAPs), vasoactive intestinal peptide (VIP) and the VPAC(1), VPAC(2) and PAC(1) receptors in human meningeal (for their role in migraine) and coronary (for potential side effects) arteries....

  1. Finite volume numerical solution to a blood flow problem in human artery

    Science.gov (United States)

    Wijayanti Budiawan, Inge; Mungkasi, Sudi

    2017-01-01

    In this paper, we solve a one dimensional blood flow model in human artery. This model is of a non-linear hyperbolic partial differential equation system which can generate either continuous or discontinuous solution. We use the Lax–Friedrichs finite volume method to solve this model. Particularly, we investigate how a pulse propagates in human artery. For this simulation, we give a single sine wave with a small time period as an impluse input on the left boundary. The finite volume method is successful in simulating how the pulse propagates in the artery. It detects the positions of the pulse for the whole time period.

  2. Relationship between media-to-lumen ratio of subcutaneous small arteries and wall-to-lumen ratio of retinal arterioles evaluated noninvasively by scanning laser Doppler flowmetry.

    Science.gov (United States)

    Rizzoni, Damiano; Porteri, Enzo; Duse, Sarah; De Ciuceis, Carolina; Rosei, Claudia Agabiti; La Boria, Elisa; Semeraro, Francesco; Costagliola, Ciro; Sebastiani, Adolfo; Danzi, Paola; Tiberio, Guido A M; Giulini, Stefano M; Docchio, Franco; Sansoni, Giovanna; Sarkar, Annamaria; Rosei, Enrico Agabiti

    2012-06-01

    Structural alterations of subcutaneous small resistance arteries, as indicated by an increased media-to-lumen ratio, are frequently present in hypertensive and/or diabetic patients, and may represent the earliest alteration observed. Furthermore, media-to-lumen ratio of small arteries evaluated by micromyography has a strong prognostic significance; however, its extensive evaluation is limited by the invasivity of the assessment, since a biopsy of subcutaneous fat is needed. Noninvasive measurement of wall-to-lumen of retinal arterioles using scanning laser Doppler flowmetry (SLDF) has recently been introduced. However, this new technique has not yet been compared to micromyographic measurement, generally considered the gold standard approach. We investigated 40 individuals and patients, 24 of them were hypertensive patients and 16 normotensive individuals. All patients underwent a biopsy of subcutaneous fat during an elective surgical intervention. Subcutaneous small resistance arteries were dissected and mounted on a wire myograph, and media-to-lumen ratio was measured. In addition, an evaluation of wall-to-lumen ratio of retinal arterioles by SLDF was performed (Heidelberg Retina Flowmeter, Heidelberg Engineering). A close correlation was observed between media-to-lumen ratio of subcutaneous small arteries and wall-to-lumen ratio of retinal arterioles (r = 0.76, P < 0.001; P < 0.001, r(2) = 0.57). A noninvasive and easily repeatable procedure (intraobserver and interobserver variation coefficient <13%) such as an evaluation of the arterioles in the fundus oculi by SLDF may provide similar information regarding microvascular morphology compared with an invasive, accurate and prognostically relevant micromyographic measurement of media-to-lumen ratio of subcutaneous small arteries.

  3. Relation of aortic calcification, wall thickness, and distensibility with severity of coronary artery disease: evaluation with coronary CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Seonah; Yong, Hwan Seok; Doo, Kyung Won; Kang, Eun-Young; Woo, Ok Hee; Choi, Eun Jung [Dept. of Radiology, Korea Univ. Guro Hospital, Korea Univ. College of Medicine, Seoul (Korea, Republic of)], e-mail: yhwanseok@naver.com

    2012-10-15

    Background Three known risk factors for aortic atherosclerosis predict the severity of coronary artery disease (CAD): aortic calcification (AC), aortic wall thickness (AWT), and aortic distensibility (AD). Purpose To determine the relationship of AC, AWT, and AD with the severity of CAD. Material and Methods A total of 104 patients who underwent both coronary CT angiography (CCTA) and invasive coronary angiography were enrolled. The severity of CAD was assessed by three methods: the segment involvement score (SIS), the segment stenosis score (SSS), and the modified Gensini score (mG). We quantified AC using the Agatston method on low-dose ungated chest CT (LDCT). We measured AWT at the thickest portion of the descending thoracic aorta on CCTA. AD was calculated as the difference between the maximum and minimum areas of the ascending aorta and the pulse pressure. The relationships between the severity of CAD and the three aortic factors were assessed. Results The AC and AWT of the thoracic aorta were significantly higher in the occlusive CAD (OCAD) group (1984.21 {+-} 2986.10 vs. 733.00 {+-} 1648.71, P = 0.01; 4.13 {+-} 1.48 vs. 3.40 {+-} 1.01, P = 0.22). Patients with OCAD had more than one epicardial coronary artery with >50% luminal stenosis. The AC (r = 0.453 with SIS; r = 0.454 with SSS; r = 0.427 with mG) and the AWT (r = 0.279 with SIS; r = 0.324 with SSS; r = 0.304 with mG) were significantly correlated with all three methods, and the AD was negatively correlated with the SIS (r = - 0.221, P < 0.05, respectively) in the unadjusted model. After adjustment for cardiovascular risk factors, only the correlations between AC and all three methods assessing CAD remained significant. Conclusion There are significant relationships between AC, AWT and AD and severity of CAD. In particular, AC measured on LDCT is the most consistent predictor of severity of CAD.

  4. Threshold Setting for Likelihood Function for Elasticity-Based Tissue Classification of Arterial Walls by Evaluating Variance in Measurement of Radial Strain

    Science.gov (United States)

    Tsuzuki, Kentaro; Hasegawa, Hideyuki; Kanai, Hiroshi; Ichiki, Masataka; Tezuka, Fumiaki

    2008-05-01

    Pathologic changes in arterial walls significantly influence their mechanical properties. We have developed a correlation-based method, the phased tracking method [H. Kanai et al.: IEEE Trans. Ultrason. Ferroelectr. Freq. Control 43 (1996) 791], for measurement of the regional elasticity of the arterial wall. Using this method, elasticity distributions of lipids, blood clots, fibrous tissue, and calcified tissue were measured in vitro by experiments on excised arteries (mean±SD: lipids 89±47 kPa, blood clots 131 ±56 kPa, fibrous tissue 1022±1040 kPa, calcified tissue 2267 ±1228 kPa) [H. Kanai et al.: Circulation 107 (2003) 3018; J. Inagaki et al.: Jpn. J. Appl. Phys. 44 (2005) 4593]. It was found that arterial tissues can be classified into soft tissues (lipids and blood clots) and hard tissues (fibrous tissue and calcified tissue) on the basis of their elasticity. However, there are large overlaps between elasticity distributions of lipids and blood clots and those of fibrous tissue and calcified tissue. Thus, it was difficult to differentiate lipids from blood clots and fibrous tissue from calcified tissue by simply thresholding elasticity value. Therefore, we previously proposed a method by classifying the elasticity distribution in each region of interest (ROI) (not a single pixel) in an elasticity image into lipids, blood clots, fibrous tissue, or calcified tissue based on a likelihood function for each tissue [J. Inagaki et al.: Jpn. J. Appl. Phys. 44 (2006) 4732]. In our previous study, the optimum size of an ROI was determined to be 1,500 µm in the arterial radial direction and 1,500 µm in the arterial longitudinal direction [K. Tsuzuki et al.: Ultrasound Med. Biol. 34 (2008) 573]. In this study, the threshold for the likelihood function used in the tissue classification was set by evaluating the variance in the ultrasonic measurement of radial strain. The recognition rate was improved from 50 to 54% by the proposed thresholding.

  5. Quantitative Measurement of Dissection Resistance in Intimal and Medial Layers of Human Coronary Arteries.

    Science.gov (United States)

    Wang, Ying; Johnson, John A; Spinale, Francis G; Sutton, Michael A; Lessner, Susan M

    2014-04-01

    The left anterior descending (LAD) coronary artery is the most frequently involved vessel in coronary artery dissection, a cause of acute coronary syndrome or sudden cardiac death. The biomechanical mechanisms underlying arterial dissection are not well understood. This study investigated the dissection properties of LAD specimens harvested from explanted hearts at the time of cardiac transplantation, from patients with primary dilated cardiomyopathy (n=12). Using a previously validated approach uniquely modified for these human LAD specimens, we quantified the local energy release rate, G, within different arterial layers during experimental dissection events (tissue tearing). Results show that the mean values of G during arterial dissection within the intima and within the media in human LADs are 20.7±16.5 J/m(2) and 10.3±5.0 J/m(2), respectively. The difference in dissection resistance between tearing events occurring within the intima and within the media is statistically significant. Our data fall in the same order of magnitude as most previous measurements of adhesive strength in other human arteries, with the differences in measured values of G within the layers most likely due to histologically observed differences in the structure and composition of arterial layers.

  6. Development of Decellularized Human Umbilical Arteries as Small-Diameter Vascular Grafts

    Science.gov (United States)

    Gui, Liqiong; Muto, Akihito; Chan, Stephen A.; Breuer, Christopher K.

    2009-01-01

    Objective Developing a tissue-engineered small-diameter (<6 mm) vascular graft for reconstructive surgery has remained a challenge for the past several decades. This study was conducted to develop a decellularized umbilical artery and to evaluate its composition, endothelial cell compatibility, mechanical properties, and in vivo stability for potential use as a small-diameter vascular graft. Methods and Results Human umbilical arteries were isolated and decellularized by incubation in CHAPS and sodium dodecyl sulfate buffers followed by incubation in endothelial growth media-2. Decellularized umbilical arteries were completely devoid of cellular and nuclear material while retaining the integrity of extracellular collagenous matrix. The mechanical strength of the decellularized umbilical artery as assessed by its burst pressure in vitro showed no significant change from its native form. Decellularized umbilical arteries supported endothelial adherence as indicated by the re-endotheliazation with a monolayer of human umbilical vein endothelial cells. Furthermore, decellularized vessels that were implanted into nude rats as abdominal aorta interposition grafts remained mechanically intact and patent for up to 8 weeks. Conclusion Decellularized human umbilical arteries preserved the extracellular matrix, supported endothelialization, and retained function in vivo for up to 8 weeks. These properties suggest the potential use of decellularized umbilical arteries as small-diameter vascular grafts. PMID:19207043

  7. Fluid-structure interaction analysis on the effect of vessel wall hypertrophy and stiffness on the blood flow in carotid artery bifurcation

    Science.gov (United States)

    Lee, Sang Hoon; Choi, Hyoung Gwon; Yoo, Jung Yul

    2012-11-01

    The effect of artery wall hypertrophy and stiffness on the flow field is investigated using three-dimensional finite element method for simulating the blood flow. To avoid the complexity due to the necessity of additional mechanical constraints, we use the combined formulation which includes both the fluid and structural equations of motion into single coupled variational equation. A P2P1 Galerkin finite element method is used to solve the Navier-Stokes equations for fluid flow and arbitrary Lagrangian-Eulerian formulation is used to achieve mesh movement. The Newmark method is employed for solving the dynamic equilibrium equations for linear elastic solid mechanics. The pulsatile, incompressible flows of Newtonian fluids constrained in the flexible wall are analyzed with Womersley velocity profile at the inlet and constant pressure at the outlet. The study shows that the stiffness of carotid artery wall affects significantly the flow phenomena during the pulse cycle. Similarly, it is found that the flow field is also strongly influenced by wall hypertrophy. This work was supported by Mid-career Researcher Program and Priority Research Centers Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2009-0079936 & 2011-0029613).

  8. Architectural and morphological assessment of rat abdominal wall muscles: comparison for use as a human model.

    Science.gov (United States)

    Brown, Stephen H M; Banuelos, Karina; Ward, Samuel R; Lieber, Richard L

    2010-09-01

    The abdominal wall is a composite of muscles that are important for the mechanical stability of the spine and pelvis. Tremendous clinical attention is given to these muscles, yet little is known about how they function in isolation or how they interact with one another. Given the morphological, vascular, and innervation complexities associated with these muscles and their proximity to the internal organs, an appropriate animal model is important for understanding their physiological and mechanical significance during function. To determine the extent to which the rat abdominal wall resembles that of human, 10 adult male Sprague-Dawley rats were killed and formalin-fixed for architectural and morphological analyses of the four abdominal wall muscles (rectus abdominis, external oblique, internal oblique, and transversus abdominis). Physiological cross-sectional areas and optimal fascicle lengths demonstrated a pattern that was similar to human abdominal wall muscles. In addition, sarcomere lengths measured in the neutral spine posture were similar to human in their relation to optimal sarcomere length. These data indicate that the force-generating and length change capabilities of these muscles, relative to one another, are similar in rat and human. Finally, the fiber lines of action of each abdominal muscle were similar to human over most of the abdominal wall. The main exception was in the lower abdominal region (inferior to the pelvic crest), where the external oblique becomes aponeurotic in human but continues as muscle fibers into its pelvic insertion in the rat. We conclude that, based on the morphology and architecture of the abdominal wall muscles, the adult male Sprague-Dawley rat is a good candidate for a model representation of human, particularly in the middle and upper abdominal wall regions.

  9. Management of a subclavian artery thrombosis causing acute anterior wall infarction and concurrent left arm ischemia in a patient with prior coronary bypass.

    Science.gov (United States)

    Akgüllü, Çağdaş; Eryılmaz, Ufuk; Zencir, Cemil; Güngör, Hasan

    2014-12-01

    We report a 57-year-old patient with acute anterior wall infarction with a history of a coronary baypass graft operation in 2007. He also had concurrent left arm cyanosis and severe pain. He had received diagnosis of pancreatic adenocarcinoma one month previously and had had his first chemotherapy in the previous week with gemcitabine and 5-fluorouracil. After the angiography, a giant thrombus was detected in the proximal left subclavian artery, deteriorating the flows of both left internal mammarian artery (LIMA) to left anterior descending (LAD) coronary artery graft, as well as the left brachial artery. The proximal subclavian artery was stented and good flow was achieved. Through the LIMA, the distal part of LAD, which was totally obstructed with probable distal thrombus embolization, was reached and a percutaneous balloon angioplasty performed. However, the no-reflow phenomenon was observed in distal LAD. A Fogarty traction of thrombus was performed successfully for the revascularization of the left arm. Approximately 30 minutes after the procedure, both angina and ST segment elevation in ECG were resolved under unfractioned heparin and nitroglycerin infusion. However, the patient died due to sepsis seven days after admission to hospital. In the literature, there are only a few previous reports on this rare clinical entity. The eitology, presentation, and the possible management strategies of this clinical entity is presented in this report.

  10. PUVB-mediated prevention of luminal narrowing after arterial wall injury: modulation of mechanical arterial properties as a putative mechanism of action

    Science.gov (United States)

    Perree, Jop; Kerindongo, Raphaela P.; van Leeuwen, Ton G. J. M.

    2001-10-01

    In a previous study we have found that the photodynamic modality PUVB (8-methoxy-Psoralen + UVB) reduces luminal narrowing after arterial endovascular injury. We hypothesized that PUVB may modulate the arterial mechanical properties and tested this hypothesis by measuring the stress as a function of the strain in segments of carotid artery. Furthermore, we have investigated the potential for PUVB-induced cross-linking of extracellular matrix proteins by gel electrophoresis. It was found that both techniques were suitable for testing our hypotheses as evidenced by a statistically significant difference for the positive control. However, no differences between A) control, B) sensitizer only, C) light only and D) PUVB-treated samples could be found with respect to macro- and micro-mechanical properties. Therefore, the hypothesis that PUVB mediates its luminal narrowing reduction effect by directly changing the arterial mechanical properties should be rejected.

  11. Myocardial bridges of the coronary arteries in the human fetal heart.

    Science.gov (United States)

    Cakmak, Yusuf Ozgür; Cavdar, Safiye; Yalin, Aymelek; Yener, Nuran; Ozdogmus, Omer

    2010-09-01

    During the last century, many investigators reported on myocardial bridges in the adult human heart. In the present study, 39 human fetal hearts (the mean gestastional age was 30 weeks) were studied for myocardial bridging, and the results were correlated with adult data. Among the 39 (27 male and 12 female) fetal hearts studied, 26 bridges were observed on 18 fetal hearts (46.2%). Ten of the bridges had one myocardial bridge, whereas double myocardial bridges were observed in eight fetal hearts. The most frequent myocardial bridges were observed on the left anterior descending artery (LAD), which had 13 bridges (50%). Eight (30.7%) myocardial bridges were on the diagonal artery, and on the posterior descending artery there were five (19.3%). Myocardial bridges were not observed on the circumflex artery. The data presented in this study may provide potentially useful information for the preoperative evaluation of the newborn and may have a clinical implication for sudden fetal death.

  12. Modelling the layer-specific three-dimensional residual stresses in arteries, with an application to the human aorta.

    Science.gov (United States)

    Holzapfel, Gerhard A; Ogden, Ray W

    2010-05-01

    This paper provides the first analysis of the three-dimensional state of residual stress and stretch in an artery wall consisting of three layers (intima, media and adventitia), modelled as a circular cylindrical tube. The analysis is based on experimental results on human aortas with non-atherosclerotic intimal thickening documented in a recent paper by Holzapfel et al. (Holzapfel et al. 2007 Ann. Biomed. Eng. 35, 530-545 (doi:10.1007/s10439-006-9252-z)). The intima is included in the analysis because it has significant thickness and load-bearing capacity, unlike in a young, healthy human aorta. The mathematical model takes account of bending and stretching in both the circumferential and axial directions in each layer of the wall. Previous analysis of residual stress was essentially based on a simple application of the opening-angle method, which cannot accommodate the three-dimensional residual stretch and stress states observed in experiments. The geometry and nonlinear kinematics of the intima, media and adventitia are derived and the associated stress components determined explicitly using the nonlinear theory of elasticity. The theoretical results are then combined with the mean numerical values of the geometrical parameters and material constants from the experiments to illustrate the three-dimensional distributions of the stretches and stresses throughout the wall. The results highlight the compressive nature of the circumferential stress in the intima, which may be associated with buckling of the intima and its delamination from the media, and show that the qualitative features of the stretch and stress distributions in the media and adventitia are unaffected by the presence or absence of the intima. The circumferential residual stress in the intima increases significantly as the associated residual deformation in the intima increases while the corresponding stress in the media (which is compressive at its inner boundary and tensile at its outer boundary

  13. Arterial supply in the human pectoralis minor muscle.

    Science.gov (United States)

    Moriya, A; Takafuji, T; Sato, Y

    1993-03-01

    In the following, we report our findings obtained as a result of injecting an acrylic pigment in the arteries supplying the pectoralis minor muscle in 50 lateral chests of 26 Japanese adults (15 males and 11 females). In the pectoralis minor muscle, the muscular bundle near the terminal is supplied by A. processus coracoideris (Pc, Sato-Takafuji, '85) or A. coracobrachialis (Cb, Sato, '80) of A. axillaris (Ax), while its middle upper and lower peripherals are supplied by A. thoracoacromialis (Ta) and A. partis abdominalis (Pab, Sato, '76), respectively. Further, the upper and lower peripherals at its origin are supplied by A. thoracica suprema (Ts) and A. thoracica lateralis (Tl), respectively. Pc, Cb, Pab and Ts may occasionally be absent. Arteries supplying this muscle are classified according to their origins and routes of distribution, as follows. Type I-a: Pc or Cb, Ta, Pab, Ts and Tl are present, 32%; Type II-a: Ts is absent from Type I-a, 14%; Type III-a: Pb and Pc are absent from Type I-a, 20%; Type IV-a: Cb, Pc and Ts are absent from Type I-a, 10%. Type b is Type a without Pab. The rates of appearance of Type I-b, II-b, III-b and IV-b were all 6%. The ratios of distribution in area a were as follows, in order of decreasing ratio: 37.6% for Pab (37 cases), 32.4% for Tl (49 cases), 30.2% for Ta (49 cases), 10.8% for Ts (32 cases), 7% for Cb (9 cases), and 6.37% for Pc. In the pectoralis minor muscle, the major supplying arteries are Pab, Tl and Ta, and where Pab was absent, this was compensated for by a branch of Ta. The total number of supplying arteries in this muscle was two to five, with the majority, or 36%, having four arteries. As for sex differences in the incidence of each type, Type I-a appeared more often in males (40%) than in females (20%). The rates according to the ribs of origin were 46%, 36%, 16%, and 2% for types 2.3.4.5, 3.4.5, 2.3.4, and 2.3.4.5.6, respectively. It was interesting that all Type II and Type IV cases without Ts corresponded

  14. The impact of exercise training on conduit artery wall thickness and remodeling in chronic heart failure patients

    NARCIS (Netherlands)

    Maiorana, A.J.; Naylor, L.H.; Exterkate, A.; Swart, A.; Thijssen, D.H.J.; Lam, K.; O'Driscoll, G.; Green, D.J.

    2011-01-01

    Exercise training is an important adjunct to medical therapy in chronic heart failure, but the extent to which exercise impacts on conduit artery remodeling is unknown. The aim of this study was to evaluate the impact of aerobic and resistance exercise training modalities on arterial remodeling in

  15. Oxidation modifies the structure and function of the extracellular matrix generated by human coronary artery endothelial cells.

    Science.gov (United States)

    Chuang, Christine Y; Degendorfer, Georg; Hammer, Astrid; Whitelock, John M; Malle, Ernst; Davies, Michael J

    2014-04-15

    ECM (extracellular matrix) materials, such as laminin, perlecan, type IV collagen and fibronectin, play a key role in determining the structure of the arterial wall and the properties of cells that interact with the ECM. The aim of the present study was to investigate the effect of peroxynitrous acid, an oxidant generated by activated macrophages, on the structure and function of the ECM laid down by HCAECs (human coronary artery endothelial cells) in vitro and in vivo. We show that exposure of HCAEC-derived native matrix components to peroxynitrous acid (but not decomposed oxidant) at concentrations >1 μM results in a loss of antibody recognition of perlecan, collagen IV, and cell-binding sites on laminin and fibronectin. Loss of recognition was accompanied by decreased HCAEC adhesion. Real-time PCR showed up-regulation of inflammation-associated genes, including MMP7 (matrix metalloproteinase 7) and MMP13, as well as down-regulation of the laminin α2 chain, in HCAECs cultured on peroxynitrous acid-treated matrix compared with native matrix. Immunohistochemical studies provided evidence of co-localization of laminin with 3-nitrotyrosine, a biomarker of peroxynitrous acid damage, in type II-III/IV human atherosclerotic lesions, consistent with matrix damage occurring during disease development in vivo. The results of the present study suggest a mechanism through which peroxynitrous acid modifies endothelial cell-derived native ECM proteins of the arterial basement membrane in atherosclerotic lesions. These changes to ECM and particularly perlecan and laminin may be important in inducing cellular dysfunction and contribute to atherogenesis.

  16. Dynamic analysis of a small artery of a human finger by optical coherence tomography

    Science.gov (United States)

    Kuwabara, Mitsuo; Takahashi, Natsuki; Takada, Daisuke; Ohmi, Masato; Haruna, Masamitsu

    2011-03-01

    OCT is highly potential for development of a new field of dynamic skin physiology, as recently reported by the authors. In this paper, we demonstrate dynamic analysis of a small artery of a human finger by the SS-OCT. Among the vascular system, only the small artery has two physiological functions both for the elastic artery (like main and middle arteries) and for muscle-controlled one (like arterioles). It, therefore, is important for dynamic analysis of blood flow and circulation. In the time-sequential OCT images obtained with 25 frames/s, it is found that the small artery makes a sharp response to sound stress for contraction and expansion while it continues pulsation in synchronization with the heartbeats. This result indicates that the small artery exhibits clearly the two physiological functions for blood flow and circulation. In response to sound stress, blood flow is controlled effectively by thickness change of the tunica media which consists of five to six layers of smooth muscles. It is thus found that the thickness of the tunica media changes remarkably in response to external stress, reflecting activity of the sympathetic nerve. The dynamic OCT of the small artery presented here will allow us not only to understand the mechanism of blood flow control and also to detect abnormal physiological functions in the whole vascular system.

  17. Local effects of atherosclerotic plaque on arterial distensibility.

    Science.gov (United States)

    Giannattasio, C; Failla, M; Emanuelli, G; Grappiolo, A; Boffi, L; Corsi, D; Mancia, G

    2001-11-01

    Hypertension, diabetes, and hypercholesterolemia are characterized by a reduction in arterial distensibility and by accelerated atherosclerosis. Whether arterial stiffening is an inherent feature of these conditions or just the consequence of the atherosclerotic clinical or subclinical lesions is not known, however. Our aim was to obtain information on this issue by directly measuring, in humans, arterial distensibility both at the site of an atherosclerotic lesion and at the proximal normal site. In 10 patients (8 men; mean+/-SEM age, 65.2+/-3.4 years) affected by monolateral hemodynamic significant internal carotid artery stenosis, we measured arterial distensibility (Wall Track System; PIE Medical) bilaterally, both at the internal carotid artery and at the common carotid artery level. In the common carotid artery, measurements were made 3 cm below the bifurcation. In the affected internal carotid artery, measurements were made at the plaque shoulder (wall thickness of 2 mm). Measurements were made in the contralateral internal carotid artery at a symmetrical level. Arterial wall thickness was measured in the same site of arterial distensibility. Arterial distensibility was less in the internal than in the common carotid artery, with a marked reduction at the plaque internal carotid artery level compared with the corresponding contralateral site (-45%, P<0.01). It was also less, however, in the common carotid artery branching into the atherosclerotic internal carotid artery than in the contralateral common carotid artery (-25%, P<0.05). Wall thickness was similar in the 2 common carotid arteries and obviously greater in the affected internal carotid artery than in the contralateral artery. Arterial distensibility was markedly less in the internal carotid artery where there was a plaque compared with the intact contralateral internal carotid artery; it was also less, however, in the common carotid artery of the affected side in comparison with the contralateral

  18. [Ruptured aneurysm at the anterior wall of the internal carotid artery in a patient with systemic lupus erythematosus and secondary antiphospholipid syndrome].

    Science.gov (United States)

    Chonan, Masashi; Fujimura, Miki; Inoue, Takashi; Tominaga, Teiji

    2011-07-01

    A 60 year-old woman, who had a 45-year history of systemic lupus erythematosus (SLE) and secondary antiphospholipid syndrome, presented with subarachnoid hemorrhage due to a ruptured aneurysm at the anterior wall of the non-branching site of the right internal carotid artery. She underwent radical surgery on the day of onset. In light of the possibility of arterial dissection, we performed extracranial-intracranial bypass prior to careful exploration of the aneurysm. Based on the finding of saccular aneurysm, she ultimately underwent neck clipping of the aneurysm without complication. Postoperative course was uneventful, and she did not suffer from cerebral vasospasm. We recommend early surgical intervention in patients with aneurysmal SAH associated with SLE, while intrinsic pathologies of SLE such as fragile vascular structure and the risk for ischemic complication should be considered.

  19. Secreted Protein Acidic and Rich in Cysteine Modulates Molecular Arterial Homeostasis of Human Arterial Smooth Muscle Cells In Vitro.

    Science.gov (United States)

    Ye, Geng-Fan; Zhu, Shao-Wei; Zhu, Shu-Gan; Li, Feng; Wang, Yun-Yan

    2016-12-01

    Secreted protein acidic and rich in cysteine (SPARC) is widely expressed in the vascular smooth muscle cells (VSMCs) of human intracranial aneurysms (IAs), but the effect and underlying mechanism of SPARC on VSMCs during the formation and progression of IAs needs to be probed. Human umbilical arterial smooth muscle cells (HUASMCs) were treated with a gradient concentrations of SPARC in vitro for different time. Cell counting kit-8 (CCK-8) assay, cell cycle, and cell apoptosis were used to investigate the effect of SPARC on HUASMCs. After exposure to 2 and 4 μg/ml SPARC, cell viability were 89.3 ± 2.00 %, and 87.57 ± 2.17 % (P IAs.

  20. In Vivo/Ex Vivo MRI-Based 3D Non-Newtonian FSI Models for Human Atherosclerotic Plaques Compared with Fluid/Wall-Only Models.

    Science.gov (United States)

    Yang, Chun; Tang, Dalin; Yuan, Chun; Hatsukami, Thomas S; Zheng, Jie; Woodard, Pamela K

    2007-01-01

    It has been recognized that fluid-structure interactions (FSI) play an important role in cardiovascular disease initiation and development. However, in vivo MRI multi-component FSI models for human carotid atherosclerotic plaques with bifurcation and quantitative comparisons of FSI models with fluid-only or structure-only models are currently lacking in the literature. A 3D non-Newtonian multi-component FSI model based on in vivo/ex vivo MRI images for human atherosclerotic plaques was introduced to investigate flow and plaque stress/strain behaviors which may be related to plaque progression and rupture. Both artery wall and plaque components were assumed to be hyperelastic, isotropic, incompressible and homogeneous. Blood flow was assumed to be laminar, non-Newtonian, viscous and incompressible. In vivo/ex vivo MRI images were acquired using histologically-validated multi-spectral MRI protocols. The 3D FSI models were solved and results were compared with those from a Newtonian FSI model and wall-only/fluid-only models. A 145% difference in maximum principal stresses (Stress-P(1)) between the FSI and wall-only models and 40% difference in flow maximum shear stress (MSS) between the FSI and fluid-only models were found at the throat of the plaque using a severe plaque sample (70% severity by diameter). Flow maximum shear stress (MSS) from the rigid wall model is much higher (20-40% in maximum MSS values, 100-150% in stagnation region) than those from FSI models.

  1. Evolución de los modelos constitutivos de respuesta pasiva para paredes arteriales//Evolution of constitutive models for passive response of the arterial walls

    Directory of Open Access Journals (Sweden)

    Guillermo Fernández‐Collazo

    2014-08-01

    Full Text Available La respuesta mecánica de las paredes arteriales se modifica como consecuencia del envejecimiento y el desarrollo de enfermedades. Estos cambios se ven reflejados en modificaciones en su estructura, composición, resistencia y forma. La predicción de su comportamiento en dependencia de su estado fisiológico usando modelos biomecánicos se muestra como una potente herramienta en el tratamiento y diagnóstico de aneurismas, ateroesclerosis, hipertensión arterial entre otras. Realizando un profundo análisis de la literatura consultada se presenta un estudio bibliográfico de los modelos constitutivos de paredes arteriales en su respuesta pasiva, clasificándolos y destacando sus principales ventajas, desventajas y la evolución de estos desde los puramente fenomenológicos hasta los más complejos.Palabras claves: modelos, arterias, respuesta pasiva, biomecánica._______________________________________________________________________________AbstractThe mechanical response of arterial walls is modified as a result of aging and disease development. These changes are reflected in changes in its composition, strength, shape and structure. The prediction of their behavior, depending on their physiological state used biomechanical models is shown as a powerful tool in the treatment and diagnosis of aneurysms, atherosclerosis, hypertensionand others. It´s presented in its passive response, a profound analysis of the literature and the bibliographic review of the constitutive models of arterial walls, classifying and highlighting their main advantages, disadvantages and the  volution from purely phenomenological to the most complex response.Key words: models, artery, passive response, biomechanics.

  2. Typology of the arteries in the human scalenus region, with special reference to the accessory ascending cervical artery.

    OpenAIRE

    Su WD; Ohtsuka A; Taguchi T; Murakami T.

    2000-01-01

    The accessory ascending cervical artery (Murakami et al., 1996), which arises from the subclavian artery and ascends between the scalenus anterior and medius muscles, was studied in 87 Japanese adult cadavers (174 sides), with special attention being given to its origin, distribution, and relationship to other arteries at the cervical or scalenus region. In 154 sides (88.5%), the accessory ascending cervical artery was found to originate from the subclavian artery behind the scalenus anterior...

  3. [Morphological signs of mitochondrial cytopathy in skeletal muscles and micro-vessel walls in a patient with cerebral artery dissection associated with MELAS syndrome].

    Science.gov (United States)

    Sakharova, A V; Kalashnikova, L A; Chaĭkovskaia, R P; Mir-Kasimov, M F; Nazarova, M A; Pykhtina, T N; Dobrynina, L A; Patrusheva, N L; Patrushev, L I; Protskiĭ, S V

    2012-01-01

    Skin and muscles biopsy specimens of a patient harboring A3243G mutation in mitochondrial DNA, with dissection of internal carotid and vertebral arteries, associated with MELAS were studied using histochemical and electron-microscopy techniques. Ragged red fibers, regional variability of SDH histochemical reaction, two types of morphologically atypical mitochondria and their aggregation were found in muscle. There was correlation between SDH histochemical staining and number of mitochondria revealed by electron microscopy in muscle tissue. Similar mitochondrial abnormality, their distribution and cell lesions followed by extra-cellular matrix mineralization were found in the blood vessel walls. In line with generalization of cytopathy process caused by gene mutation it can be supposed that changes found in skin and muscle microvessels also exist in large cerebral vessels causing the vessel wall "weakness", predisposing them to dissection.

  4. Amendment on the strain measurement of thin-walled human skull shell as intracranial pressure changes

    Institute of Scientific and Technical Information of China (English)

    Xianfang Yue; Li Wang; Feng Zhou

    2008-01-01

    The human skuU,composed of tabula externa,tabula interna,and a porous diploe sandwiched in between,is deformed with changing intracranial pressure (ICP).Because the human skull's thickness is only 6 mm,it is simplified as a thin-walled shell. The objective of this article is to analyze the strain of the thin-walled shell by the stress-strain calculation of a human skull with changing ICP.Under the same loading conditions,using finite element analysis (FEA),the strains of the human skull were calculated and the results were compared with the measurements of the simulative experiment in vitro.It is demonstrated that the strain of the thin-walled shell is totally measured by pasting the one-way strain foils on the exterior surface of the shell with suitable amendment for data.The amendment scope of the measured strain values of the thin-walled shell is from 13.04% to 22.22%.

  5. Nitric oxide inhibits neointimal hyperplasia following vascular injury via differential, cell-specific modulation of SOD-1 in the arterial wall.

    Science.gov (United States)

    Bahnson, Edward S M; Koo, Nathaniel; Cantu-Medellin, Nadiezhda; Tsui, Aaron Y; Havelka, George E; Vercammen, Janet M; Jiang, Qun; Kelley, Eric E; Kibbe, Melina R

    2015-01-30

    Superoxide (O2(•-)) promotes neointimal hyperplasia following arterial injury. Conversely, nitric oxide ((•)NO) inhibits neointimal hyperplasia through various cell-specific mechanisms, including redox regulation. What remains unclear is whether (•)NO exerts cell-specific regulation of the vascular redox environment following arterial injury to inhibit neointimal hyperplasia. Therefore, the aim of the present study was to assess whether (•)NO exerts cell-specific, differential modulation of O2(•-) levels throughout the arterial wall, establish the mechanism of such modulation, and determine if it regulates (•)NO-dependent inhibition of neointimal hyperplasia. In vivo, (•)NO increased superoxide dismutase-1 (SOD-1) levels following carotid artery balloon injury in a rat model. In vitro, (•)NO increased SOD-1 levels in vascular smooth muscle cells (VSMC), but had no effect on SOD-1 in endothelial cells or adventitial fibroblasts. This SOD-1 increase was associated with an increase in sod1 gene expression, increase in SOD-1 activity, and decrease in O2(•-) levels. Lastly, to determine the role of SOD-1 in (•)NO-mediated inhibition of neointimal hyperplasia, we performed the femoral artery wire injury model in wild type and SOD-1 knockout (KO) mice, with and without (•)NO. Interestingly, (•)NO inhibited neointimal hyperplasia only in wild type mice, with no effect in SOD-1 KO mice. In conclusion, these data show the cell-specific modulation of O2(•-) by (•)NO through regulation of SOD-1 in the vasculature, highlighting its importance on the inhibition of neointimal hyperplasia. These results also shed light into the mechanism of (•)NO-dependent redox balance, and suggest a novel VSMC redox target to prevent neointimal hyperplasia.

  6. [Architectonics of gastric arterial bed in norm, after Nissen fundoplication, and its different combination with splenectomy and left gastric artery ligation].

    Science.gov (United States)

    Alekseyev, V S; Gaivoronskiy, I V; Kotiv, B N; Kuz'min, A A; Nichiporuk, G I

    2014-01-01

    A comparative study of the effect of the combination of Nissen fundoplication, different variants of splenectomy ligation of left gastric artery on stomach wall arterial bed blood fillability was carried out on 40 human corpses in 6 research series. The red lead paint suspension was used for the injection of arterial bed. It was shown that combination of Nissen operation andligation of stomach short arteries during splenectomy and left gastric artery trunk in its intraligamental part resulted in the impairment of the stomach wall blood supply. In the gastric fundus area avascular zones measuring from 2.5 x 3.0 to 5.0 x 10.0 cm and larger, were detected. The stomach wall of the given areas is potentially prone to necrosis. Avascular zones in the stomach wall were not observed when short gastric arteries were preserved.

  7. Vasodilator activity of hydrogen sulfide (H2S) in human mesenteric arteries.

    Science.gov (United States)

    Materazzi, Serena; Zagli, Giovanni; Nassini, Romina; Bartolini, Ilenia; Romagnoli, Stefano; Chelazzi, Cosimo; Benemei, Silvia; Coratti, Andrea; De Gaudio, Angelo Raffaele; Patacchini, Riccardo

    2017-01-01

    The role of endogenous H2S has been highlighted as a gaseous transmitter. The vascular smooth muscle inhibitory effects of H2S have been characterized in isolated aorta and mesenteric arteries in rats and mice. Our study was aimed at investigating the vascular effects of H2S on human isolated mesenteric arteries and examining the underlying mechanisms involved. All experiments were performed on rings (4-8mm long) of human mesenteric arteries obtained from patients undergoing abdominal surgery. Ethical approval was obtained from the Ethics Committee of the University Hospital of the University of Florence (app. N. 2015/0024947). The effect of NaHS, an H2S donor, was determined using noradrenaline pre-contracted human isolated mesenteric rings. NaHS evoked a concentration-dependent relaxation (EC50 57μM). In contrast, homocysteine, an endogenous precursor of H2S, failed to affect human isolated mesenteric rings. Vasorelaxant response to NaHS was reduced by endothelium removal, application of the nitric oxide synthase inhibitor L-NAME and ODQ inhibitor of cyclic GMP. SQ 22536, an adenylate-cyclase inhibitor, failed to block NaHS-induced vasorelaxation. Inhibition of endogenous prostanoid production by indomethacin significantly reduced NaHS induced vasorelaxation. The role of potassium channels was also examined: blockers of the Ca(2+)-dependent potassium channel, charybdotoxin and apamin, failed to have any influence on the relaxant response to NaHS on this vascular tissue. In summary, H2S induced relaxation of isolated rings of human mesenteric arteries. Endothelium-dependent related mechanisms with the stimulation of ATP-sensitive potassium channels represents important cellular mechanisms for H2S effect on human mesenteric arteries. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Viscoelastic properties of healthy human artery measured in saline solution by AFM based indentation technique

    Energy Technology Data Exchange (ETDEWEB)

    Lundkvist, A.; Lilleodden, E.; Sickhaus, W.; Kinney, J.; Pruitt, L.; Balooch, M.

    1998-02-09

    Using an Atomic Force Microscope with an attachment for indentation, we have measured local, in vitro mechanical properties of healthy femoral artery tissue held in saline solution. The elastic modulus (34. 3 kPa) and viscoelastic response ({tau}sub{epsilon} {equals} 16.9 s and {tau}sub{sigma} {equals} 29.3 s) of the unstretched,intimal vessel wall have been determined using Sneddon theory and a three element model(standard linear solid) for viscoelastic materials. The procedures necessary to employ the indenting attachment to detect elastic moduli in the kPa range in liquid are described.

  9. Increased levels of endothelin ETB receptor mRNA in human omental arteries after organ culture

    DEFF Research Database (Denmark)

    Möller, S; Adner, M; Edvinsson, L

    1998-01-01

    1. Using competitive reverse transcription-polymerase chain reaction (RT-PCR) and in vitro pharmacology, smooth muscle endothelin ETB receptor expression was studied in segments of human omental artery, fresh and after organ culture for 1 and 5 days. 2. The competitive RT-PCR assay used in the pr...

  10. Pleiotropic effects of statins in distal human pulmonary artery smooth muscle cells

    Directory of Open Access Journals (Sweden)

    Butrous Ghazwan S

    2011-10-01

    Full Text Available Abstract Background Recent clinical data suggest statins have transient but significant effects in patients with pulmonary arterial hypertension. In this study we explored the molecular effects of statins on distal human pulmonary artery smooth muscle cells (PASMCs and their relevance to proliferation and apoptosis in pulmonary arterial hypertension. Methods Primary distal human PASMCs from patients and controls were treated with lipophilic (simvastatin, atorvastatin, mevastatin and fluvastatin, lipophobic (pravastatin and nitric-oxide releasing statins and studied in terms of their DNA synthesis, proliferation, apoptosis, matrix metalloproteinase-9 and endothelin-1 release. Results Treatment of human PASMCs with selected statins inhibited DNA synthesis, proliferation and matrix metalloproteinase-9 production in a concentration-dependent manner. Statins differed in their effectiveness, the rank order of anti-mitogenic potency being simvastatin > atorvastatin > > pravastatin. Nevertheless, a novel nitric oxide-releasing derivative of pravastatin (NCX 6550 was effective. Lipophilic statins, such as simvastatin, also enhanced the anti-proliferative effects of iloprost and sildenafil, promoted apoptosis and inhibited the release of the mitogen and survival factor endothelin-1. These effects were reversed by mevalonate and the isoprenoid intermediate geranylgeranylpyrophosphate and were mimicked by inhibitors of the Rho and Rho-kinase. Conclusions Lipophilic statins exert direct effects on distal human PASMCs and are likely to involve inhibition of Rho GTPase signalling. These findings compliment some of the recently documented effects in patients with pulmonary arterial hypertension.

  11. In vivo transfer of lipoprotein(a) into human atherosclerotic carotid arterial intima

    DEFF Research Database (Denmark)

    Nielsen, Lars Bo; Grønholdt, Marie-Louise; Schroeder, T V;

    1997-01-01

    The aim of this study was to compare the atherogenic potential of lipoprotein(a) [Lp(a)] and LDL by measuring the intimal clearance of these two plasma lipoproteins in the atherosclerotic intima of the human carotid artery in vivo. Autologous 131I-Lp(a) and 125I-LDL were mixed and reinjected intr...

  12. Geometry-based pressure drop prediction in mildly diseased human coronary arteries

    NARCIS (Netherlands)

    J.T.C. Schrauwen (Jelle); J.J. Wentzel (Jolanda); A.F.W. van der Steen (Ton); F.J.H. Gijsen (Frank)

    2014-01-01

    textabstractPressure drop (△. p) estimations in human coronary arteries have several important applications, including determination of appropriate boundary conditions for CFD and estimation of fractional flow reserve (FFR). In this study a △. p prediction was made based on geometrical features deri

  13. Distinct Differences on Neointima Formation in Immunodeficient and Humanized Mice after Carotid or Femoral Arterial Injury

    Science.gov (United States)

    Moser, Jill; van Ark, Joris; van Dijk, Marcory C.; Greiner, Dale L.; Shultz, Leonard D.; van Goor, Harry; Hillebrands, Jan-Luuk

    2016-01-01

    Percutaneous coronary intervention is widely adopted to treat patients with coronary artery disease. However, restenosis remains an unsolved clinical problem after vascular interventions. The role of the systemic and local immune response in the development of restenosis is not fully understood. Hence, the aim of the current study was to investigate the role of the human immune system on subsequent neointima formation elicited by vascular injury in a humanized mouse model. Immunodeficient NOD.Cg-PrkdcscidIL2rgtm1Wjl(NSG) mice were reconstituted with human (h)PBMCs immediately after both carotid wire and femoral cuff injury were induced in order to identify how differences in the severity of injury influenced endothelial regeneration, neointima formation, and homing of human inflammatory and progenitor cells. In contrast to non-reconstituted mice, hPBMC reconstitution reduced neointima formation after femoral cuff injury whereas hPBMCs promoted neointima formation after carotid wire injury 4 weeks after induction of injury. Neointimal endothelium and smooth muscle cells in the injured arteries were of mouse origin. Our results indicate that the immune system may differentially respond to arterial injury depending on the severity of injury, which may also be influenced by the intrinsic properties of the arteries themselves, resulting in either minimal or aggravated neointima formation. PMID:27759053

  14. In-depth characterization of CGRP receptors in human intracranial arteries

    DEFF Research Database (Denmark)

    Jansen-Olesen, Inger; Jørgensen, Linda; Engel, Ulla

    2003-01-01

    in cerebral and middle meningeal arteries with and without endothelium as well as in microvessels and in the endothelial cells. Human and rat alpha- and beta-CGRP, amylin, adrenomedullin and [acetamidomethyl-Cys(2,7)]human CGRP induced strong concentration-dependent relaxation of human cerebral and middle...... meningeal arteries. Removal of the endothelium neither changed the maximum relaxant response nor the pIC(50) values for alpha- and beta-CGRP as compared to the responses in arteries with an intact endothelium. Human alpha-CGRP-(8-37) caused a shift of h alpha- and h beta-CGRP-induced relaxations in cerebral...... and middle meningeal arteries. Calculation of pK(B) values revealed that h alpha-CGRP-(8-37) could not significantly discriminate between relaxations induced by h alpha-CGRP (pK(B) around 6.8) and h beta-CGRP (pK(B) around 5.4). There was no significant difference in pK(B) value of h alpha-CGRP-(8-37) on h...

  15. Effect of cholesterol lowering on stiffness of aortic and femoral arterial walls in rabbits on a high fat diet

    Institute of Scientific and Technical Information of China (English)

    XUE Li; XU Wan-hai; XU Jin-zhi; ZHANG Tong; BI Hong-yuan; SHEN Bao-zhong

    2009-01-01

    Background Researches in arterial elasticity have increased over the past few years. We investigated the effects of simvastatin on vascular stiffness in fat fed rabbits by ultrasonography.Methods Thirty rabbits were assigned randomly to 3 groups: normal control group (A), the cholesterol group (B), simvastatin group (C: high fat diet for 4 weeks and high fat diet + simvastatin for further 4 weeks). Stiffness coefficient, pressure strain elastic modulus and velocity of pulse waves in abdominal aorta and femoral artery were measured by ultrasonographic echo tracking at the end of the 4th and the 8th weeks.Results At the end of the 4th week, stiffness coefficient, pressure strain elastic modulus and pulse wave velocity of femoral artery were significantly increased in group B compared with those in group A. Similarly, at the end of the 8th week, the same parameters of abdominal aorta were significantly increased in group B compared with those in group A. In contrast, stiffness coefficient, pressure strain elastic modulus and pulse wave velocity of femoral artery were significantly decreased in group C compared with those in group B, however, there was no significant difference in parameters of abdominal aorta between groups B and C.Conclusion Short term administration of simvastatin can improve the elasticity of femoral artery but not abdominal aorta.

  16. Experimental study of the pathogenesis of moyamoya disease: histological changes in the arterial wall caused by immunological reactions in monkeys.

    Directory of Open Access Journals (Sweden)

    Terai Y

    2003-10-01

    Full Text Available Moyamoya disease is a progressive vascular disorder of unknown etiology. Theories of inflammatory and immunologic mechanisms have been proposed as the pathogeneses. We have designed a new method of administering N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP for experimental induction of moyamoya disease using an intravascular interventional technique combined with rod-shaped embolic materials made from lactic acid-glycolic acid copolymer. The embolic materials containing MDP were repeatedly injected into the right internal carotid artery of monkeys in the embolic group. Intravenous injections of MDP solution alone were performed in the intravenous group. Histological examination of the arteries demonstrated reduplication and lamination of the internal elastic laminae, which corresponded with findings of moyamoya disease in both groups. These histological changes occurred not only in the intracranial arteries on the embolization side, but also in the contralateral intracranial and even extracranial arteries. The changes were more prominent in the intravenous group than in the embolic group. We conclude that the systemic humoral factors induced by MDP in this study may be important in the pathogeneses of moyamoya disease. Our observations suggest that moyamoya disease is a systemic vascular disease and has an etiologic factor affecting both intracranial and extracranial arteries

  17. Arterial diameter during central volume depletion in humans

    DEFF Research Database (Denmark)

    Iversen, Helle Klingenberg; Madsen, P; Matzen, S;

    1995-01-01

    .3) to 2.2 (SEM 0.3) 1.min-1] and heart rate [HR, from 64 (SEM 3) to 100 (SEM 7) beats.min-1], mean arterial pressure (MAP, from 77 (SEM 4) to 89 (SEM 2) mmHg [10.3 (SEM 0.53 to 11.9 (SEM 0.27) kPa]) and total peripheral resistance (TPR, from 19 (SEM 2) to 34 (SEM 4) mmHg.min.1-1 [2.5 (SEM 0.27) to 4.......5 (SEM 0.53) kPa.min.1-1]) increased; but with the appearance of presyncopal symptoms, HR, MAP and TPR were reduced to 65 (SEM 8) beats.min-1, 46 (SEM 4) mmHg [6.1 (SEM 0.53) kPa] and 18 (SEM 3) mmHg.min.1-1 [2.4 (SEM 0.4) kPa.min-1.1-1], respectively (P

  18. Angiotensin II receptor mRNA expression and vasoconstriction in human coronary arteries

    DEFF Research Database (Denmark)

    Wackenfors, Angelica; Pantev, Emil; Emilson, Malin;

    2004-01-01

    Angiotensin II is a potent vasoconstrictor that is implicated in the pathogenesis of hypertension, heart failure and atherosclerosis. In the present study, angiotensin II receptor mRNA expression levels were quantified by real-time polymerase chain reaction and the vasocontractile responses...... to angiotensin II were characterised by in vitro pharmacology in endothelium-denuded human coronary arteries. Angiotensin II type 1 (AT(1)) and type 2 (AT(2)) receptor mRNA expression levels were significantly down-regulated in arteries from patients with heart failure as compared to controls. The angiotensin II...

  19. [Morphometric characteristics of human colon wall as anatomic basis for microsurgical anastomoses].

    Science.gov (United States)

    Konovalov, D Iu

    2007-01-01

    This article describes the morphometric characteristics and some peculiarities of microsurgical anatomy of human colon wall. The thickness of colon wall varied from 495 to 3501 microm in the areas between teniae and from 1103 to 4007 microm in the areas of teniae, the average values were equal to 1693+93.3 and 2602+85 microm, respectively. The width of teniae was 3.5-10.3 mm (6.2+0.3 mm on the average). The thickness of tunica muscularis along the colon prevailed over the thickness of other tunics and increased caudally, while the thickness of submucosa diminished. Marked variability and small thickness of both the colon wall and its layers, differences of these characteristics in the areas of teniae musculares and between them support the expediency of the application of microsurgical operative technique in the operations performed on the colon.

  20. Diagnosis of atherosclerosis in human carotid artery by FT-Raman spectroscopy: Principal Components Analysis algorithm

    Science.gov (United States)

    Nogueira, Grazielle V.; Silveira, Landulfo, Jr.; Martin, Airton A.; Zangaro, Renato A.; Pacheco, Marcos T.; Chavantes, Maria C.; Zampieri, Marcelo; Pasqualucci, Carlos A. G.

    2004-07-01

    FT- Raman Spectroscopy (FT-Raman) could allow identification and evaluation of human atherosclerotic lesions. A Raman spectrum can provide biochemical information of arteries which can help identifying the disease status and evolution. In this study, it is shown the results of FT-Raman for identification of human carotid arteries in vitro. Fragments of human carotid arteries were analyzed using a FT-Raman spectrometer with a Nd:YAG laser at 1064nm operating at an excitation power of 300mW. Spectra were obtained with 250 scans and spectral resolution of 4 cm-1. Each collection time was approximately 8 min. A total of 75 carotid fragments were spectroscopically scanned and FT-Raman results were compared with histopathology. Principal Components Analysis (PCA) was used to model an algorithm for tissue classification into three categories: normal, atherosclerotic plaque without calcification and atherosclerotic plaque with calcification. Non-atherosclerotic (normal) artery, atherosclerotic plaque and calcified plaque exhibit different spectral signatures related to biochemicals presented in each tissue type, such as, bands of collagen and elastin (proteins), cholesterol and its esters and calcium hydroxyapatite and carbonate apatite respectively. Results show that there is 96% match between classifications based on PCA algorithm and histopathology. The diagnostic applied over all 75 samples had sensitivity and specificity of about 89% and 100%, respectively, for atherosclerotic plaque and 100% and 98% for calcified plaque.

  1. Is prophylactic embolization of the hepatic falciform artery needed before radioembolization in patients with {sup 99m}Tc-MAA accumulation in the anterior abdominal wall?

    Energy Technology Data Exchange (ETDEWEB)

    Ahmadzadehfar, Hojjat; Sabet, Amir; Muckle, Marianne; Haslerud, Torjan; Biersack, Hans Juergen; Ezziddin, Samer [University Hospital Bonn, Department of Nuclear Medicine, Bonn (Germany); Moehlenbruch, Markus; Meyer, Carsten; Wilhelm, Kai; Schild, Hans Heinz [University Hospital Bonn, Department of Radiology, Bonn (Germany)

    2011-08-15

    While influx of chemoembolic agents into the hepatic falciform artery (HFA) from the hepatic artery can cause supraumbilical skin rash, epigastric pain and even skin necrosis, the significance of a patent HFA in patients undergoing radioembolization is not completely clear. Furthermore, the presence of tracer in the anterior abdominal wall seen in {sup 99m}Tc-macroaggregated albumin ({sup 99m}Tc-MAA) images, which is generally performed prior to radioembolization, has been described as a sign of a patent HFA. The aim of this retrospective study was to evaluate the incidence and consequences of {sup 99m}Tc-MAA accumulation in the anterior abdominal wall, indicating a patent HFA, in patients undergoing radioembolization of liver tumours. A total of 224 diagnostic hepatic angiograms combined with {sup 99m}Tc-MAA SPECT/CT were acquired in 192 patients with different types of cancer, of whom 142 were treated with a total of 214 radioembolization procedures. All patients received a whole-body scan, and planar and SPECT/CT scans of the abdomen. Only patients with extrahepatic {sup 99m}Tc-MAA accumulation in the anterior abdominal wall were included in this study. Posttreatment bremsstrahlung SPECT/CT and follow-up results for at least 3 months served as reference standards. Tracer accumulation in the anterior abdominal wall was present in pretreatment {sup 99m}Tc-MAA SPECT/CT images of 18 patients (9.3%). The HFA was found and embolized by radiologists before treatment in one patient. In the remaining patients radioembolization was performed without any modification in the treatment plan despite the previously mentioned extrahepatic accumulation. Only one patient experienced abdominal muscle pain above the navel, which started 24 h after treatment and lasted for 48 h without any skin changes. The remaining patients did not experience any relevant side effects during the follow-up period. Side effects after radioembolization in patients with tracer accumulation in the

  2. Intimal and medial contributions to the hydraulic resistance of the arterial wall at different pressures: a combined computational and experimental study.

    Science.gov (United States)

    Chooi, K Y; Comerford, A; Sherwin, S J; Weinberg, P D

    2016-06-01

    The hydraulic resistances of the intima and media determine water flux and the advection of macromolecules into and across the arterial wall. Despite several experimental and computational studies, these transport processes and their dependence on transmural pressure remain incompletely understood. Here, we use a combination of experimental and computational methods to ascertain how the hydraulic permeability of the rat abdominal aorta depends on these two layers and how it is affected by structural rearrangement of the media under pressure. Ex vivo experiments determined the conductance of the whole wall, the thickness of the media and the geometry of medial smooth muscle cells (SMCs) and extracellular matrix (ECM). Numerical methods were used to compute water flux through the media. Intimal values were obtained by subtraction. A mechanism was identified that modulates pressure-induced changes in medial transport properties: compaction of the ECM leading to spatial reorganization of SMCs. This is summarized in an empirical constitutive law for permeability and volumetric strain. It led to the physiologically interesting observation that, as a consequence of the changes in medial microstructure, the relative contributions of the intima and media to the hydraulic resistance of the wall depend on the applied pressure; medial resistance dominated at pressures above approximately 93 mmHg in this vessel.

  3. Effects of valsartan on angiotensin II-induced migration of human coronary artery smooth muscle cells.

    Science.gov (United States)

    Kohno, M; Ohmori, K; Nozaki, S; Mizushige, K; Yasunari, K; Kano, H; Minami, M; Yoshikawa, J

    2000-11-01

    The migration as well as proliferation of coronary artery medial smooth muscle cells (SMC) into the intima is proposed to be an important process of intimal thickening in coronary atherosclerosis. In the current study, we examined the effects of the angiotensin type 1 receptor antagonist valsartan on angiotensin II (Ang II)-induced migration of cultured human coronary artery SMC using Boyden's chamber methods. Ang II significantly stimulated human coronary artery SMC migration in a concentration-dependent manner between 10(-6) and 10(-8) mol/l when cells of passage 4 to 6 were used. However, the migration response to Ang II was moderately decreased in cells of passage 10 to 12, and was markedly decreased in cells of passage 15 to 17, compared to that of passage 4 to 6. Ang II-induced migration was blocked by the Ang II type 1 (AT1) receptor antagonist valsartan in a concentration-dependent manner. By contrast, the Ang II type 2 (AT2) receptor antagonist PD 123319 did not affect Ang II-induced migration. Ang II modestly increased the cell number of human coronary artery SMC after a 24-h incubation. This increase in cell numbers was also clearly blocked by valsartan, but not by PD 123319. These results indicate that Ang II stimulates migration as well as proliferation via AT1 receptors in human coronary artery SMC when cells of passage 4 to 6 are used. Valsartan may prevent the progression of coronary atherosclerosis through an inhibition of Ang II-induced migration and proliferation in these cells, although in vivo evidence is lacking.

  4. Endothelin-dependent vasoconstriction in human uterine artery: application to preeclampsia.

    Directory of Open Access Journals (Sweden)

    Clotilde Dechanet

    Full Text Available BACKGROUND: Reduced uteroplacental perfusion, the initiating event in preeclampsia, is associated with enhanced endothelin-1 (ET-1 production which feeds the vasoconstriction of uterine artery. Whether the treatments of preeclampsia were effective on ET-1 induced contraction and could reverse placental ischemia is the question addressed in this study. We investigated the effect of antihypertensive drugs used in preeclampsia and of ET receptor antagonists on the contractile response to ET-1 on human uterine arteries. METHODOLOGY/PRINCIPAL FINDINGS: Experiments were performed, ex vivo, on human uterine artery samples obtained after hysterectomy. We studied variations in isometric tension of arterial rings in response to the vasoconstrictor ET-1 and evaluated the effects of various vasodilators and ET-receptor antagonists on this response. Among antihypertensive drugs, only dihydropyridines were effective in blocking and reversing the ET-1 contractile response. Their efficiency, independent of the concentration of ET-1, was only partial. Hydralazine, alpha-methyldopa and labetalol had no effect on ET-1 induced contraction which is mediated by both ET(A and ET(B receptors in uterine artery. ET receptors antagonists, BQ-123 and BQ-788, slightly reduced the amplitude of the response to ET-1. Combination of both antagonists was more efficient, but it was not possible to reverse the maximal ET-1-induced contraction with antagonists used alone or in combination. CONCLUSION: Pharmacological drugs currently used in the context of preeclampsia, do not reverse ET-1 induced contraction. Only dihydropyridines, which partially relax uterine artery previously contracted with ET-1, might offer interesting perspectives to improve placental perfusion.

  5. Effect of severe acidosis on vasoactive effects of epinephrine and norepinephrine in human distal mammary artery.

    Science.gov (United States)

    Vidal, Charles; Grassin-Delyle, Stanislas; Devillier, Philippe; Naline, Emmanuel; Lansac, Emmanuel; Ménasché, Philippe; Faisy, Christophe

    2014-05-01

    Acidosis is a very common pathologic process in perioperative management. However, how to correct severe acidosis to improve the efficacy of vasoconstrictors in hemodynamically unstable patients is still debated. The present study investigated whether severe extracellular acidosis influences the vasoactive properties of vasoconstrictors on human isolated arteries. Segments of intact distal internal mammary arteries were removed from 41 patients undergoing artery bypass grafting. The arterial rings were washed in Krebs-Henseleit solution and suspended in an organ bath. The rings were set at a pretension equivalent of 100 mm Hg, and the relaxation response to 10 μM acetylcholine was verified. Concentration-response curves for epinephrine, norepinephrine, methoxamine (α1A/D-adrenoceptor agonist), phenylephrine (equipotent agonist of α1A/B-adrenoceptors), and clonidine (α2-adrenoceptor agonist) were achieved under control conditions (pH 7.40) and under acidic conditions by substitution of the Krebs-Henseleit solution with a modified solution. Decreasing the pH from 7.40 to 7.20, 7.0, or 6.80 did not significantly alter the potency and efficacy of epinephrine and norepinephrine, although the standardized effect size was sometimes large. Severe acidosis (pH 6.80) did not significantly change the potency and efficacy of phenylephrine and clonidine, although it increased the efficacy and potency of methoxamine (P acidosis did not impair the vasoactive properties of epinephrine and norepinephrine in human medium-size arteries until pH 6.80. The results of the present study also suggest that acidosis might potentiate arterial responsiveness to vasoconstrictors, mostly by way of the α1D-adrenoceptor. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

  6. Digital analysis of the dynamics of the arterial supply to the human foetal kidneys.

    Science.gov (United States)

    Kuczera, Małgorzata; Gajda, Grzegorz; Gielecki, Jerzy S

    2003-11-01

    Variations in the renal arteries in human individuals and foetuses have already been well studied. Contemporary trends in visualisation techniques focus on the evaluation of the dynamic parameters of blood flow in the vessels (speed, pulsatility, resistance). Most of these data have been obtained by the means of Doppler ultrasound (Fig. 1, 2). The authors have not found any anatomical database containing information about variability in the volume of the foetal renal arteries. The aim of the study is to design a database for variation in foetal renal artery volume in relation to foetal age and sex. The material consisted of digital images of the renal arteries filled with LBS-latex taken from 30 foetuses aged 12-19 Hbd. Digital analysis of the arteries was made with a unique form of software. The program is a 2D vector graphic editor using spliced functions of Bezier. Foetal age is estimated according to the last menstrual period and measurement of manual foot length and femur length (FL) as determined by ultrasound.

  7. Simulation and signal processing of through wall UWB radar for human being's periodic motions detection

    Science.gov (United States)

    Li, Jing; Liu, Fengshan; Xu, Penglong; Zeng, Zhaofa

    2013-05-01

    The human's Micro-Doppler signatures resulting from breathing, arm, foot and other periodic motion can provide valuable information about the structure of the moving parts and may be used for identification and classification purposes. In this paper, we carry out simulate with FDTD method and through wall experiment with UWB radar for human being's periodic motion detection. In addition, Advancements signal processing methods are presented to classify and to extract the human's periodic motion characteristic information, such as Micro-Doppler shift and motion frequency. Firstly, we apply the Principal Component Analysis (PCA) with singular value decomposition (SVD) to denoise and extract the human motion signal. Then, we present the results base on the Hilbert-Huang transform (HHT) and the S transform to classify and to identify the human's micro-Doppler shift characteristics. The results demonstrate that the combination of UWB radar and various processing methods has potential to detect human's Doppler signatures effectively.

  8. Premature birth is associated with not fully differentiated contractile smooth muscle cells in human umbilical artery.

    Science.gov (United States)

    Roffino, S; Lamy, E; Foucault-Bertaud, A; Risso, F; Reboul, R; Tellier, E; Chareyre, C; Dignat-George, F; Simeoni, U; Charpiot, P

    2012-06-01

    Smooth muscle cells (SMCs) participate to the regulation of peripheral arterial resistance and blood pressure. To assume their function, SMCs differentiate throughout the normal vascular development from a synthetic phenotype towards a fully differentiated contractile phenotype by acquiring a repertoire of proteins involved in contraction. In human fetal muscular arteries and umbilical arteries (UAs), no data are available regarding the differentiation of SMCs during the last trimester of gestation. The objective of this study was to characterize the phenotype of SMCs during this gestation period in human UAs. We investigated the phenotype of SMCs in human UAs from very preterm (28-31 weeks of gestation), late preterm (32-35 weeks) and term (37-41 weeks) newborns using biochemical and immunohistochemical detection of α-actin, smooth muscle myosin heavy chain, smoothelin, and non-muscle myosin heavy chain. We found that the number of SMCs positive for smoothelin in UAs increased with gestational age. Western blot analysis revealed a higher content of smoothelin in term compared to very preterm UAs. These results show that SMCs in human UAs gradually acquire a fully differentiated contractile phenotype during the last trimester of gestation and thus that premature birth is associated with not fully differentiated contractile SMCs in human UAs. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Analysis of Human's Motions Based on Local Mean Decomposition in Through-wall Radar Detection

    Science.gov (United States)

    Lu, Qi; Liu, Cai; Zeng, Zhaofa; Li, Jing; Zhang, Xuebing

    2016-04-01

    Observation of human motions through a wall is an important issue in security applications and search-and rescue. Radar has advantages in looking through walls where other sensors give low performance or cannot be used at all. Ultrawideband (UWB) radar has high spatial resolution as a result of employment of ultranarrow pulses. It has abilities to distinguish the closely positioned targets and provide time-lapse information of targets. Moreover, the UWB radar shows good performance in wall penetration when the inherently short pulses spread their energy over a broad frequency range. Human's motions show periodic features including respiration, swing arms and legs, fluctuations of the torso. Detection of human targets is based on the fact that there is always periodic motion due to breathing or other body movements like walking. The radar can gain the reflections from each human body parts and add the reflections at each time sample. The periodic movements will cause micro-Doppler modulation in the reflected radar signals. Time-frequency analysis methods are consider as the effective tools to analysis and extract micro-Doppler effects caused by the periodic movements in the reflected radar signal, such as short-time Fourier transform (STFT), wavelet transform (WT), and Hilbert-Huang transform (HHT).The local mean decomposition (LMD), initially developed by Smith (2005), is to decomposed amplitude and frequency modulated signals into a small set of product functions (PFs), each of which is the product of an envelope signal and a frequency modulated signal from which a time-vary instantaneous phase and instantaneous frequency can be derived. As bypassing the Hilbert transform, the LMD has no demodulation error coming from window effect and involves no negative frequency without physical sense. Also, the instantaneous attributes obtained by LMD are more stable and precise than those obtained by the empirical mode decomposition (EMD) because LMD uses smoothed local

  10. Elastin organization in pig and cardiovascular disease patients' pericardial resistance arteries

    DEFF Research Database (Denmark)

    Bloksgaard, Maria; Leurgans, Thomas; Nissen, Inger

    2015-01-01

    Peripheral vascular resistance is increased in essential hypertension. This involves structural changes of resistance arteries and stiffening of the arterial wall, including remodeling of the extracellular matrix. We hypothesized that biopsies of the human parietal pericardium, obtained during...... coronary artery bypass grafting or cardiac valve replacement surgeries, can serve as a source of resistance arteries for structural research in cardiovascular disease patients. We applied two-photon excitation fluorescence microscopy to study the parietal pericardium and isolated pericardial resistance...

  11. [Quantitative Analysis of Wall Shear Stress for Human Carotid Bifurcation at Cardiac Phases by the Use of Phase Contrast Cine Magnetic Resonance Imaging: Computational Fluid Dynamics Study].

    Science.gov (United States)

    Saho, Tatsunori; Onishi, Hideo

    2015-12-01

    Detailed strategy for regional hemodynamics is significant for knowledge of plaque development on vascular diseases such as atherosclerosis. The aim of this study was to derive relation between atherosclerosis and hemodynamics at human carotid bifurcation by the use of computational fluid dynamics (CFD), and to provide more accurate hemodynamic information. Blood velocity datasets at common carotid artery were obtained by phase-contrast cine magnetic resonance imaging (PC cine MRI). Carotid bifurcation model was computed for systolic, mid-diastolic, and end-diastolic phase. Comparison of wall shear stress (WSS) was performed for each cardiac phase. PC cine MRI provided velocity measurement for common carotid artery with various cardiac phases. The blood velocity had acute variation from 0.21 m/s to 1.07 m/s at systolic phase. The variation of WSS during cardiac phase was presented at carotid bifurcation model. High shear stress area was observed at dividing wall for all cardiac phases. The systole-diastole WSS ratio was 10.15 at internal carotid side of bifurcation. And low shear stress (cine MRI was allowed to determine an accurate analysis condition. This led to the representation of hemodynamics in vivo.

  12. Concentration polarization of atherogenic lipids in the arterial system

    Institute of Scientific and Technical Information of China (English)

    DENG; Xiaoyan; (邓小燕); WANG; Guixue; (王贵学)

    2003-01-01

    The transport of atherogenic lipids (LDL) in a straight segment of an artery with a semi-permeable wall was simulated numerically. The numerical analysis predicted that a mass transport phenomenon called 'concentration polarization' of LDL might occur in the arterial system. Under normal physiological flow conditions, the luminal surface LDL concentration was 5%-14% greater than the bulk concentration in a straight segment of an artery. The luminal surface LDL concentration at the arterial wall was flow-dependent, varying linearly with the filtration rate across the arterial wall and inversely with wall shear rate. At low wall shear rate, the luminal surface LDL concentration was very sensitive to changes in flow conditions, decreasing sharply as wall shear rate increased. In order to verify the numerical analysis, the luminal surface concentration of bovine serum albumin (as a tracer macromolecule) in the canine carotid artery was measured in vitro by directly taking liquid samples from the luminal surface of the artery. The experimental result was in very good agreement with the numerical analysis. The authors believe that the mass transport phenomenon of 'concentration polarization' may indeed exist in the human circulation and play an important role in the localization of atherosclerosis.

  13. Toxicology Study of Single-walled Carbon Nanotubes and Reduced Graphene Oxide in Human Sperm

    OpenAIRE

    2016-01-01

    Carbon-based nanomaterials such as single-walled carbon nanotubes and reduced graphene oxide are currently being evaluated for biomedical applications including in vivo drug delivery and tumor imaging. Several reports have studied the toxicity of carbon nanomaterials, but their effects on human male reproduction have not been fully examined. Additionally, it is not clear whether the nanomaterial exposure has any effect on sperm sorting procedures used in clinical settings. Here, we show that ...

  14. A quantitative method for studying human arterial baroreflexes

    Science.gov (United States)

    Eckberg, Dwain L.; Fritsch, Janice M.; Goble, Ross L.

    1991-01-01

    A new system is described that delivers precise, stereotyped pressure changes to the human neck and elicits neurally-mediated heart rate changes. The centerpiece of this system is a Silastic chamber that is strapped to the anterior neck. This chamber is connected to a stepping-motor-controlled bellows assembly. A strain-gauge transducer measures the intensity of pressure changes. The entire system is controlled by microprocessors, and both stimuli and responses are displayed on a digital oscilloscope. The end-product of this system is a reproducible baroreceptor stimulus-cardiac response relation that can be recorded rapidly and safely in astronauts in space.

  15. Arterial structure and function in vascular ageing: are you as old as your arteries?

    Science.gov (United States)

    Thijssen, Dick H J; Carter, Sophie E; Green, Daniel J

    2016-04-15

    Advancing age may be the most potent independent predictor of future cardiovascular events, a relationship that is not fully explained by time-related changes in traditional cardiovascular risk factors. Since some arteries exhibit differential susceptibility to atherosclerosis, generalisations regarding the impact of ageing in humans may be overly simplistic, whereas in vivo assessment of arterial function and health provide direct insight. Coronary and peripheral (conduit, resistance and skin) arteries demonstrate a gradual, age-related impairment in vascular function that is likely to be related to a reduction in endothelium-derived nitric oxide bioavailability and/or increased production of vasoconstrictors (e.g. endothelin-1). Increased exposure and impaired ability for defence mechanisms to resist oxidative stress and inflammation, but also cellular senescence processes, may contribute to age-related changes in vascular function and health. Arteries also undergo structural changes as they age. Gradual thickening of the arterial wall, changes in wall content (i.e. less elastin, advanced glycation end-products) and increase in conduit artery diameter are observed with older age and occur similarly in central and peripheral arteries. These changes in structure have important interactive effects on artery function, with increases in small and large arterial stiffness representing a characteristic change with older age. Importantly, direct measures of arterial function and structure predict future cardiovascular events, independent of age or other cardiovascular risk factors. Taken together, and given the differential susceptibility of arteries to atherosclerosis in humans, direct measurement of arterial function and health may help to distinguish between biological and chronological age-related change in arterial health in humans.

  16. Pial artery and subarachnoid width response to apnoea in normal humans.

    Science.gov (United States)

    Wszedybyl-Winklewska, Magdalena; Wolf, Jacek; Swierblewska, Ewa; Kunicka, Katarzyna; Gruszecki, Marcin; Guminski, Wojciech; Winklewski, Pawel J; Frydrychowski, Andrzej F; Bieniaszewski, Leszek; Narkiewicz, Krzysztof

    2015-09-01

    Little is known about intracranial pressure (ICP)-cerebral haemodynamic interplay during repetitive apnoea. A recently developed method based on near-infrared transillumination/backscattering sounding (NIR-T/BSS) noninvasively measures changes in pial artery pulsation (cc-TQ) as well as subarachnoid width (sas-TQ) in humans. We tested the complex response of the pial artery and subarachnoid width to apnoea using this method. The pial artery and subarachnoid width response to consecutive apnoeas lasting 30, 60 s and maximal breath-hold (91.1 ± 23.1 s) were studied in 20 healthy volunteers. The cc-TQ and sas-TQ were measured using NIR-T/BSS; cerebral blood flow velocity (CBFV), pulsatility index and resistive index were measured using Doppler ultrasound of the left internal carotid artery; heart rate (HR) and beat-to-beat SBP and DBP blood pressure were recorded using a Finometer; end-tidal CO2 (EtCO2) was measured using a medical gas analyser. Apnoea evoked a multiphasic response in blood pressure, pial artery compliance and ICP. First, SBP declined, which was accompanied by an increase in cc-TQ and sas-TQ. Directly after these changes, SBP exceeded baseline values, which was followed by a decline in cc-TQ and the return of sas-TQ to baseline. During these initial changes, CBFV remained stable. Towards the end of the apnoea, BP, cc-TQ and CBFV increased, whereas pulsatility index, resistive index and sas-TQ declined. Changes in sas-TQ were linked to changes in EtCO2, HR and SBP. Apnoea is associated with ICP swings, closely reflecting changes in EtCO2, HR and peripheral BP. The baroreflex influences the pial artery response.

  17. Comparison of the vasodilator responses of isolated human and rat middle meningeal arteries to migraine related compounds

    DEFF Research Database (Denmark)

    Grände, Gustaf; Labruijere, Sieneke; Haanes, Kristian Agmund

    2014-01-01

    , telcagepant) were applied to the isolated arteries, and both induced a significant decrease of the effect of exogenously administrated CGRP. In experiments on rat middle meningeal arteries, pre-contracted with PGF2α, similar tendencies were seen. When the pre-contraction was switched to K+ in a separate...... series of experiments, CGRP and sildenafil significantly relaxed the arteries. CONCLUSIONS: Still no definite answer can be given as to why pain is experienced during an attack of migraine. No clear correlation was found between the efficacy of a substance as a meningeal artery vasodilator in human...

  18. Lipopolysaccharide and Interleukin 1 Augment the Effects of Hypoxia and Inflammation in Human Pulmonary Arterial Tissue

    Science.gov (United States)

    Ziesche, Rolf; Petkov, Venzeslav; Williams, John; Zakeri, Schaker M.; Mosgoller, Wilhelm; Knofler, Martin; Block, Lutz H.

    1996-10-01

    The combined effects of hypoxia and interleukin 1, lipopolysaccharide, or tumor necrosis factor α on the expression of genes encoding endothelial constitutive and inducible nitric oxide synthases, endothelin 1, interleukin 6, and interleukin 8 were investigated in human primary pulmonary endothelial cells and whole pulmonary artery organoid cultures. Hypoxia decreased the expression of constitutive endothelial nitric oxide synthase (NOS-3) mRNA and NOS-3 protein as compared with normoxic conditions. The inhibition of expression of NOS-3 corresponded with a reduced production of NO. A combination of hypoxia with bacterial lipopolysaccharide, interleukin 1β , or tumor necrosis factor α augmented both effects. In contrast, the combination of hypoxia and the inflammatory mediators superinduced the expression of endothelin 1, interleukin 6, and interleukin 8. Here, we have shown that inflammatory mediators aggravate the effect of hypoxia on the down-regulation of NOS-3 and increase the expression of proinflammatory cytokines in human pulmonary endothelial cells and whole pulmonary artery organoid cultures.

  19. Oxidative modification of high density lipoprotein induced by cultured human arterial smooth muscle cells

    Institute of Scientific and Technical Information of China (English)

    江渝; 刘红; 彭家和; 叶治家; 何凤田; 董燕麟; 刘秉文

    2003-01-01

    Objective: To observe the oxidative modification of high density lipoprotein (HDL) induced by cultured human arterial smooth muscle cells (SMCs). Methods: HDL cocultured with SMCs at 37℃ in 48 h was subjected, and native HDL (N-HDL) served as control. Oxidative modification of HDL was identified by using agarose gel electrophoresis. Absorbances of conjugated diene (CD) and lipid hydroperoxide (LOOH) were measured with ultraviolet spectrophotometry at 234 and 560 nm respectively, and fluorescence intensity of thiobarbuturic acid reaction substance (TBARS) with fluorescence spectrophotometry at 550 nm emission wavelength with excitation at 515 nm. Results: In comparison with N-HDL, the electrophoretic mobility of SMCs-cocultured HDL was increased, and the contents of CD, LOOH and TBARS HDL were very significantly higher than those of the control HDL (P<0.01). Conclusion: Oxidative modification of HDL can be induced by human arterial SMCs.

  20. Region-based geometric modelling of human airways and arterial vessels.

    Science.gov (United States)

    Ding, Songlin; Ye, Yong; Tu, Jiyuan; Subic, Aleksandar

    2010-03-01

    Anatomically precise geometric models of human airways and arterial vessels play a critical role in the analysis of air and blood flows in human bodies. The established geometric modelling methods become invalid when the model consists of bronchioles or small vessels. This paper presents a new method for reconstructing the entire airway tree and carotid vessels from point clouds obtained from CT or MR images. A novel layer-by-layer searching algorithm has been developed to recognize branches of the airway tree and arterial vessels from the point clouds. Instead of applying uniform accuracy to all branches regardless of the number of available points, the surface patches on each branch are constructed adaptively based on the number of available elemental points, which leads to the elimination of distortions occurring at small bronchi and vessels.

  1. Flow and wall shear stress in end-to-side and side-to-side anastomosis of venous coronary artery bypass grafts

    Directory of Open Access Journals (Sweden)

    Poulikakos Dimos

    2007-09-01

    Full Text Available Abstract Purpose Coronary artery bypass graft (CABG surgery represents the standard treatment of advanced coronary artery disease. Two major types of anastomosis exist to connect the graft to the coronary artery, i.e., by using an end-to-side or a side-to-side anastomosis. There is still controversy because of the differences in the patency rates of the two types of anastomosis. The purpose of this paper is to non-invasively quantify hemodynamic parameters, such as mass flow and wall shear stress (WSS, in end-to-side and side-to-side anastomoses of patients with CABG using computational fluid dynamics (CFD. Methods One patient with saphenous CABG and end-to-side anastomosis and one patient with saphenous CABG and side-to-side anastomosis underwent 16-detector row computed tomography (CT. Geometric models of coronary arteries and bypasses were reconstructed for CFD analysis. Blood flow was considered pulsatile, laminar, incompressible and Newtonian. Peri-anastomotic mass flow and WSS were quantified and flow patterns visualized. Results CFD analysis based on in-vivo CT coronary angiography data was feasible in both patients. For both types of CABG, flow patterns were characterized by a retrograde flow into the native coronary artery. WSS variations were found in both anastomoses types, with highest WSS values at the heel and lowest WSS values at the floor of the end-to-side anastomosis. In contrast, the highest WSS values of the side-to-side anastomosis configuration were found in stenotic vessel segments and not in the close vicinity of the anastomosis. Flow stagnation zones were found in end-to-side but not in side-to-side anastomosis, the latter also demonstrating a smoother stream division throughout the cardiac cycle. Conclusion CFD analysis of venous CABG based on in-vivo CT datasets in patients was feasible producing qualitative and quantitative information on mass flow and WSS. Differences were found between the two types of anastomosis

  2. The low-dose atorvastatin and valsartan combination effectively protects the arterial wall from atherogenic diet-induced impairment in the guinea pig.

    Science.gov (United States)

    Janić, Miodrag; Lunder, Mojca; Zupan, Janja; Černe, Darko; Marc, Janja; Drevenšek, Gorazd; Šabovič, Mišo

    2014-11-15

    New preventive strategies for atherosclerosis are needed. In this study, we tested whether a new therapeutic approach consisting of low-dose treatment with a statin and sartan combination could prevent atherogenic diet-induced impairment of the arterial wall in guinea pigs. Twenty-five Dunkin-Hartley guinea pigs were randomly assigned to five experimental groups: 1) normal diet; 2) atherogenic diet (AD); 3) AD + a low-dose atorvastatin and valsartan combination (5mg/kg/day and 2.4mg/kg/day, respectively); 4) AD + low-dose atorvastatin (5mg/kg/day); 5) AD + low-dose valsartan (2.4mg/kg/day). After 8 weeks of treatment, the animals were killed, blood samples collected and thoracic and abdominal aortas isolated. The atherogenic diet significantly impaired maximal thoracic aorta endothelium-dependent relaxation by 40.1% relative to the normal diet. The low-dose combination, compared to the separate drugs, completely preserved thoracic aorta endothelium-dependent relaxation at the level of the group receiving normal diet. This substantial effect was associated with a significant change in the expression of NOS3 (R=0.93; P=0.0002) and IL1b (R=-0.79; P=0.003) genes. In addition, treatment with the low-dose combination or the separate drugs also prevented atherosclerotic plaque formation. We found that treatment with the low-dose atorvastatin and valsartan combination has the capability to completely protect the arterial wall from atherogenic diet-induced damage in the guinea pig model. Further studies evaluating this new therapeutic approach are desirable.

  3. Wavelet transform analysis to assess oscillations in pial artery pulsation at the human cardiac frequency.

    Science.gov (United States)

    Winklewski, P J; Gruszecki, M; Wolf, J; Swierblewska, E; Kunicka, K; Wszedybyl-Winklewska, M; Guminski, W; Zabulewicz, J; Frydrychowski, A F; Bieniaszewski, L; Narkiewicz, K

    2015-05-01

    Pial artery adjustments to changes in blood pressure (BP) may last only seconds in humans. Using a novel method called near-infrared transillumination backscattering sounding (NIR-T/BSS) that allows for the non-invasive measurement of pial artery pulsation (cc-TQ) in humans, we aimed to assess the relationship between spontaneous oscillations in BP and cc-TQ at frequencies between 0.5 Hz and 5 Hz. We hypothesized that analysis of very short data segments would enable the estimation of changes in the cardiac contribution to the BP vs. cc-TQ relationship during very rapid pial artery adjustments to external stimuli. BP and pial artery oscillations during baseline (70s and 10s signals) and the response to maximal breath-hold apnea were studied in eighteen healthy subjects. The cc-TQ was measured using NIR-T/BSS; cerebral blood flow velocity, the pulsatility index and the resistive index were measured using Doppler ultrasound of the left internal carotid artery; heart rate and beat-to-beat systolic and diastolic blood pressure were recorded using a Finometer; end-tidal CO2 was measured using a medical gas analyzer. Wavelet transform analysis was used to assess the relationship between BP and cc-TQ oscillations. The recordings lasting 10s and representing 10 cycles with a frequency of ~1 Hz provided sufficient accuracy with respect to wavelet coherence and wavelet phase coherence values and yielded similar results to those obtained from approximately 70cycles (70s). A slight but significant decrease in wavelet coherence between augmented BP and cc-TQ oscillations was observed by the end of apnea. Wavelet transform analysis can be used to assess the relationship between BP and cc-TQ oscillations at cardiac frequency using signals intervals as short as 10s. Apnea slightly decreases the contribution of cardiac activity to BP and cc-TQ oscillations.

  4. Through-wall imaging and characterization of human activity using ultrawideband (UWB) random noise radar

    Science.gov (United States)

    Lai, Chieh-Ping; Narayanan, Ram M.

    2005-05-01

    Recent terrorist activities and law-enforcement situations involving hostage situations underscore the need for effective through-wall imaging. Current building interior imaging systems are based on short-pulse waveforms, which require specially designed antennas to subdue unwanted ringing. In addition, periodically transmitted pulses of energy are easily recognizable by the intelligent adversary who may employ appropriate countermeasures to confound detection. A coherent polarimetric random noise radar architecture is being developed based on UWB technology and software defined radio, which has great promise in its ability to covertly image obscured targets. The main advantages of the random noise radar lie in two aspects: first, random noise waveform has an ideal "thumbtack" ambiguity function, i.e., its down range and cross range resolution can be separately controlled, thus providing unambiguous high resolution imaging at any distance; second, random noise waveform is inherently low probability of intercept (LPI) and low probability of detection (LPD), i.e., it is immune from detection, jamming, and interference. Thus, it is an ideal candidate sensor for covert imaging of obscured regions in hostile environments. The coherency in the system can be exploited to field a fully-polarimetric system that can take advantage of polarization features in target recognition. Moving personnel can also be detected using Doppler processing. Simulation studies are used to analyze backscattered signals from the walls, and humans and other targets behind the walls. Real-time data processing shows human activity behind the wall and human target tracking. The high resolution provides excellent multipath and clutter rejection.

  5. Age determination of vessel wall hematoma in spontaneous cervical artery dissection: A multi-sequence 3T Cardiovascular Magnetic resonance study

    Directory of Open Access Journals (Sweden)

    Habs Maximilian

    2011-11-01

    Full Text Available Abstract Background Previously proposed classifications for carotid plaque and cerebral parenchymal hemorrhages are used to estimate the age of hematoma according to its signal intensities on T1w and T2w MR images. Using these classifications, we systematically investigated the value of cardiovascular magnetic resonance (CMR in determining the age of vessel wall hematoma (VWH in patients with spontaneous cervical artery dissection (sCAD. Methods 35 consecutive patients (mean age 43.6 ± 9.8 years with sCAD received a cervical multi-sequence 3T CMR with fat-saturated black-blood T1w-, T2w- and TOF images. Age of sCAD was defined as time between onset of symptoms (stroke, TIA or Horner's syndrome and the CMR scan. VWH were categorized into hyperacute, acute, early subacute, late subacute and chronic based on their signal intensities on T1w- and T2w images. Results The mean age of sCAD was 2.0, 5.8, 15.7 and 58.7 days in patients with acute, early subacute, late subacute and chronic VWH as classified by CMR (p Conclusions Signal intensities of VWH in sCAD vary over time and multi-sequence CMR can help to determine the age of an arterial dissection. Furthermore, findings of this study suggest that the time course of carotid hematomas differs from that of cerebral hematomas.

  6. Flow visualization and 1- and 3-D laser-Doppler-anemometer measurements in models of human carotid arteries.

    Science.gov (United States)

    Liepsch, D; Pflugbeil, G; Matsuo, T; Lesniak, B

    1998-04-01

    Pulsatile flow, wall distensibility, non-Newtonian flow characteristics of blood in flow separation regions, and high/low blood pressure were studied in elastic silicon rubber models having a compliance similar to human vessels and the same surface structure as the biological intima models of (1) a healthy carotid artery model, (2) a 90% stenosis in the ICA, and (3) 80% stenosis in both the internal and external carotid arteries. Flow was visualized for steady flow and pulsatile studies to localize flow separation regions and reattachment points. Local velocity was measured with a 1-, 2-, or 3-D laser-Doppler-anemometer (LDA). Flow in the unstenosed model was Re = 250. In the stenosed models, the Re number decreased to Re = 180 and 213 under the same experimental conditions. High velocity fluctuations with vortices were found in the stenosed models. The jet flow in the stenosis increased up to 4 m/s. With an increasing bifurcation angle, the separation regions in the ECA and ICA increased. Increased flow (Re = 350) led to an increase in flow separation and high velocity shear gradients. The highest shear stresses were nearly 20 times higher than normal. The 90% stenosis created high velocity shear gradients and velocity fluctuations. Downstream of the stenoses, eddies were found over the whole cross-section. In the healthy model a slight flow separation region was observed in the ICA at the branching cross-section whereas in the stenosed models, the flow separation regions extended far into the ICA. We conclude that a detailed understanding of flow is necessary before vascular surgery is performed especially before artificial grafts or patches are implanted.

  7. Monitoring of gadolinium-BOPTA uptake into the vessel wall during magnetic resonance (MR)-guided angioplasty of the peripheral arteries with a paclitaxel/gadolinium-BOPTA-coated balloon. An experimental study at 3 Tesla

    Energy Technology Data Exchange (ETDEWEB)

    Neizel, M.; Kelm, M. [University Hospital Duesseldorf (Germany). Dept. of Cardiology, Pneumology and Angiology; Ruebben, A.; Weiss, N. [Aachen Resonance, Aachen (Germany); Guenther, R.W. [University Hospital Aachen (Germany). Dept. of Radiology; Krombach, G.A. [University Hospital Giessen (Germany). Dept. of Radiology

    2014-04-15

    Purpose: The success of paclitaxel distribution within the vessel wall during paclitaxel-coated balloon angioplasty to prevent restenosis cannot be monitored under X-ray guidance. The aim of this pilot study was to demonstrate the feasibility of monitoring Gadolinium-BOPTA delivery within the vessel wall during magnetic resonance (MR)-guided paclitaxel/Gadolinium-BOPTA-coated balloon angioplasty of the peripheral arteries. Materials and methods: 6 pigs (47 ± 2 kg) were investigated. All experiments were performed using a 3 Tesla MR scanner. MR-guided bilaterial angioplasty of the iliac arteries was performed using a paclitaxel/MR contrast agent-coated balloon catheter. The feasibility of monitoring the delivery of Gadolinium-BOPTA to the vessel was assessed in 4 animals. In two additional animals, bilateral stenosis was surgically induced in the iliac arteries. Delivery of paclitaxel to the vessel wall was monitored using a 3 D T1-weighted gradient echo (GE) sequence for delineation of the vessel wall. Normalized signal intensity (SI) of the vessel wall was measured before and repeatedly after the intervention for 45 min. in all animals. Results: Paclitaxel/gadolinium-BOPTA-coated balloon angioplasty was successfully accomplished in all iliac arteries (n = 12). In animals with stenosis MR-angiography demonstrated successful dilatation (n = 4). The normalized SI of the vessel wall on T1-weighted GE images significantly increased after the intervention in all animals with and without stenosis for more than 45 min. (p < 0.001). Conclusion: Monitoring of Gadolinium-BOPTA into the vessel wall during MR-guided coated balloon angioplasty is feasible. This is a first step towards providing a tool for the online control of homogenous drug delivery after paclitaxel-coated balloon angioplasty. (orig.)

  8. In Vitro Vasoactive Effects of Levobupivacaine and Ropivacaine on the Isolated Human Umbilical Artery and Vein

    Directory of Open Access Journals (Sweden)

    Alper Kılıçaslan

    2011-06-01

    Full Text Available Objective: In this in vitro study, we investigated the vasoactive effects of levobupivacaine and ropivacaine on vascular smooth muscle derived from human umbilical arteries and veins.Material and Methods: The strips were mounted in tissue baths at 37°C continuously gassed with 5% CO2 in oxygen for isometric recording of contractile activity on a polygraph. The endothelium of some tissues was mechanically removed to assess the influence of the endothelium on contractility. The strips were precontracted with serotonin (10-6 M 5-HT; n=7. After obtaining the maximal contraction, responses obtained by adding levobupivacaine and ropivacaine (10-9-10-4 M; n=7 cumulatively were recorded. Contractions were expressed as the (% of 5HT maximal response percentage of 5 HT’s maximal response.Results: Both levobupivacaine and ropivacaine induce a concentration-dependent contraction in the smooth muscle cells of umbilical arteries and veins. Maximum contractile response (Emax of levobupivacaine (79.2±2.5, 71.1±2.6 was higher than ropivacaine (68.4±2, 36.2±2.8 on both umbilical arteries and veins. There were no statistically significant differences between contraction responses of endothelium-intact and endothelium-denuded tissues. Conclusion: The results suggest that, in high concentrations, levobupivacaine and ropivacaine may affect umbilical blood flow by contracting the umbilical artery and vein, thus reducing fetal blood flow.

  9. A novel human artery model to assess the magnetic accumulation of SPIONs under flow conditions

    Science.gov (United States)

    Janikowska, Agata; Matuszak, Jasmin; Lyer, Stefan; Schreiber, Eveline; Unterweger, Harald; Zaloga, Jan; Groll, Jürgen; Alexiou, Christoph; Cicha, Iwona

    2017-01-01

    Magnetic targeting utilises the properties of superparamagnetic iron oxide nanoparticles (SPIONs) to accumulate particles in specified vasculature regions under an external magnetic field. As the behaviour of circulating particles varies depending on nanoparticle characteristics, magnetic field strength and flow dynamics, we established an improved ex vivo model in order to estimate the magnetic capture of SPIONs in physiological-like settings. We describe here a new, easy to handle ex vivo model of human umbilical artery. Using this model, the magnetic targeting of different types of SPIONs under various external magnetic field gradients and flow conditions was investigated by atomic emission spectroscopy and histology. Among tested particles, SPION-1 with lauric acid shell had the largest capacity to accumulate at the specific artery segment. SPION-2 (lauric acid/albumin-coated) were also successfully targeted, although the observed peak in the iron content under the tip of the magnet was smaller than for SPION-1. In contrast, we did not achieve magnetic accumulation of dextran-coated SPION-3. Taken together, the umbilical artery model constitutes a time- and cost-efficient, 3R-compliant tool to assess magnetic targeting of SPIONs under flow. Our results further imply the possibility of an efficient in vivo targeting of certain types of SPIONs to superficial arteries. PMID:28176885

  10. Effects and mechanisms of action of sildenafil citrate in human chorionic arteries

    Directory of Open Access Journals (Sweden)

    Lynch Tadhg

    2009-04-01

    Full Text Available Abstract Objectives Sildenafil citrate, a specific phosphodiesterase-5 inhibitor, is increasingly used for pulmonary hypertension in pregnancy. Sildenafil is also emerging as a potential candidate for the treatment of intra-uterine growth retardation and for premature labor. Its effects in the feto-placental circulation are not known. Our objectives were to determine whether phosphodiesterase-5 is present in the human feto-placental circulation, and to characterize the effects and mechanisms of action of sildenafil citrate in this circulation. Study Design Ex vivo human chorionic plate arterial rings were used in all experiments. The presence of phosphodiesterase-5 in the feto-placental circulation was determined by western blotting and immunohistochemical staining. In a subsequent series of pharmacologic studies, the effects of sildenafil citrate in pre-constricted chorionic plate arterial rings were determined. Additional studies examined the role of cGMP and nitric oxide in mediating the effects of sildenafil. Results Phosphodiesterase-5 mRNA and protein was demonstrated in human chorionic plate arteries. Immunohistochemistry demonstrated phosphodiesterase-5 within the arterial muscle layer. Sildenafil citrate produced dose dependent vasodilatation at concentrations at and greater than 10 nM. Both the direct cGMP inhibitor methylene blue and the cGMP-dependent protein kinase inhibitor Rp-8-Br-PET-cGMPS significantly attenuated the vasodilation produced by sildenafil citrate. Inhibition of NO production with L-NAME did not attenuate the vasodilator effects of sildenafil. In contrast, sildenafil citrate significantly enhanced the vasodilation produced by the NO donor sodium nitroprusside. Conclusion Phosphodiesterase-5 is present in the feto-placental circulation. Sildenafil citrate vasodilates the feto-placental circulation via a cGMP dependent mechanism involving increased responsiveness to NO.

  11. Effects and mechanisms of action of sildenafil citrate in human chorionic arteries.

    LENUS (Irish Health Repository)

    Maharaj, Chrisen H

    2009-01-01

    OBJECTIVES: Sildenafil citrate, a specific phosphodiesterase-5 inhibitor, is increasingly used for pulmonary hypertension in pregnancy. Sildenafil is also emerging as a potential candidate for the treatment of intra-uterine growth retardation and for premature labor. Its effects in the feto-placental circulation are not known. Our objectives were to determine whether phosphodiesterase-5 is present in the human feto-placental circulation, and to characterize the effects and mechanisms of action of sildenafil citrate in this circulation. STUDY DESIGN: Ex vivo human chorionic plate arterial rings were used in all experiments. The presence of phosphodiesterase-5 in the feto-placental circulation was determined by western blotting and immunohistochemical staining. In a subsequent series of pharmacologic studies, the effects of sildenafil citrate in pre-constricted chorionic plate arterial rings were determined. Additional studies examined the role of cGMP and nitric oxide in mediating the effects of sildenafil. RESULTS: Phosphodiesterase-5 mRNA and protein was demonstrated in human chorionic plate arteries. Immunohistochemistry demonstrated phosphodiesterase-5 within the arterial muscle layer. Sildenafil citrate produced dose dependent vasodilatation at concentrations at and greater than 10 nM. Both the direct cGMP inhibitor methylene blue and the cGMP-dependent protein kinase inhibitor Rp-8-Br-PET-cGMPS significantly attenuated the vasodilation produced by sildenafil citrate. Inhibition of NO production with L-NAME did not attenuate the vasodilator effects of sildenafil. In contrast, sildenafil citrate significantly enhanced the vasodilation produced by the NO donor sodium nitroprusside. CONCLUSION: Phosphodiesterase-5 is present in the feto-placental circulation. Sildenafil citrate vasodilates the feto-placental circulation via a cGMP dependent mechanism involving increased responsiveness to NO.

  12. Effect of the endothelin family of peptides on human coronary artery smooth-muscle cell migration.

    Science.gov (United States)

    Kohno, M; Yokokawa, K; Yasunari, K; Kano, H; Minami, M; Yoshikawa, J

    1998-01-01

    The migration of coronary artery medial smooth-muscle cells (SMCs) is one of the key events in the process of intimal thickening in coronary atherosclerotic lesions. The objectives of the present study were to determine whether any of the three isoforms of endothelin (ET), ET-1, ET-2, and ET-3, or an intermediate form of ET, big ET-1, induces migration of human coronary artery SMCs, and to investigate the possible interaction of ET peptides and well-known migration-stimulatory factors, platelet-derived growth factor (PDGF)-BB and angiotensin II (Ang II), on SMC migration by the Boyden's chamber method. None of the ET peptides alone induced SMC migration between 10(-9) and 10(-7) mol/L. In contrast, ET-1 and ET-2 significantly induced SMC migration in the presence of low concentrations of PDGF-BB (0.5 ng/mL) or Ang II (10(-9) mol/L), although ET-3 was less active (ET-1 = ET-2 > ET-3). In contrast, big ET-1 was without significant activity on PDGF-BB-or Ang II-induced SMC migration. The potentiation of SMC migration by ET peptides was clearly inhibited by the ETA receptor antagonist BG-123 in a concentration-dependent manner. These results suggest that the ET family of peptides, especially ET-1 and ET-2, can induce human coronary artery SMC migration in combination with PDGF-BB or Ang II, probably via ETA receptors. Taken together with the finding that the concentrations of ET, PDGF-BB and Ang II are locally increased at sites of endothelial injury, this indicates that ET may be an initial stimulus for human coronary artery medial SMC recruitment during coronary atherosclerosis, possibly in combination with PDGF-BB or Ang II.

  13. Histology-validated x-ray tomography for imaging human coronary arteries

    Science.gov (United States)

    Buscema, Marzia; Schulz, Georg; Deyhle, Hans; Khimchenko, Anna; Matviykiv, Sofiya; Holme, Margaret N.; Hipp, Alexander; Beckmann, Felix; Saxer, Till; Michaud, Katarzyna; Müller, Bert

    2016-10-01

    Heart disease is the number one cause of death worldwide. To improve therapy and patient outcome, the knowledge of anatomical changes in terms of lumen morphology and tissue composition of constricted arteries is crucial for designing a localized drug delivery to treat atherosclerosis disease. Traditional tissue characterization by histology is a pivotal tool, although it brings disadvantages such as vessel morphology modification during decalcification and slicing. X-ray tomography in absorption and phase contrast modes yields a deep understanding in blood vessel anatomy in healthy and diseased stages: measurements in absorption mode make visible highly absorbing tissue components including cholesterol plaques, whereas phase contrast tomography gains better contrast of the soft tissue components such as vessel walls. Established synchrotron radiation-based micro-CT techniques ensure high performance in terms of 3D visualization of highly absorbing and soft tissues.

  14. Ischemic heart disease down-regulates angiotensin type 1 receptor mRNA in human coronary arteries

    DEFF Research Database (Denmark)

    Wackenfors, Angelica; Emilson, Malin; Ingemansson, Richard;

    2004-01-01

    Angiotensin II is important in the development of cardiovascular disease. In the present study, angiotensin II receptor mRNA levels were quantified by real-time polymerase chain reaction (real-time PCR) in human coronary arteries from patients with ischemic heart disease and controls. Furthermore......, the suitability of artery culture for studying angiotensin receptor changes was evaluated by in vitro pharmacology and real-time PCR. The angiotensin type 1 (AT1) receptor mRNA levels were down-regulated in human coronary arteries from patients with ischemic heart disease as compared to controls (P

  15. Rabbit Model of Human Gliomas: Implications for Intra-Arterial Drug Delivery

    Science.gov (United States)

    Qin, Huamin; Janowski, Miroslaw; Pearl, Monica S.; Malysz-Cymborska, Izabela; Li, Shen; Eberhart, Charles G.

    2017-01-01

    The prognosis for malignant brain tumors remains poor despite a combination of surgery, radiotherapy, and chemotherapy. This is partly due to the blood-brain barrier, a major obstacle that prevents therapeutic agents from effectively reaching the tumor. We have recently developed a method for precise and predictable opening of the blood-brain barrier via the intra-arterial administration of mannitol, a hyperosmolar agent, in a rabbit model, whose vascular anatomy facilitates the use of standard interventional neuroradiology techniques and devices. To date, however, no protocols are available that enable human glioma modeling in rabbits. In this article, we report on the xenotransplantation of a human glioblastoma (GBM-1) in adult New Zealand rabbits. We induced multi-drug immunosuppression (Mycophenolate Mofetil, Dexamethasone, Tacrolimus) and stereotactically implanted GBM-1 tumor cells into rabbit brains. The rabbits were followed for 42 days, monitored by MRI and body weight measurements, and underwent postmortem histopathological analysis. On MRI, brain tumors were identified on T2-weighted scans. On histopathology, tumors were detected with hematoxylin/eosin and their human origin was confirmed with immunohistochemistry against human-specific antigens. Our method for human glioma modeling in rabbits provides the foundation to test novel treatment strategies, including intra-arterial therapeutic agent delivery. PMID:28103265

  16. Resistance artery creatine kinase mRNA and blood pressure in humans.

    Science.gov (United States)

    Karamat, Fares A; Oudman, Inge; Ris-Stalpers, Carrie; Afink, Gijs B; Keijser, Remco; Clark, Joseph F; van Montfrans, Gert A; Brewster, Lizzy M

    2014-01-01

    Hypertension remains the main risk factor for cardiovascular death. Environmental and biological factors are known to contribute to the condition, and circulating creatine kinase was reported to be the main predictor of blood pressure in the general population. This was proposed to be because of high resistance artery creatine kinase-BB rapidly regenerating ATP for vascular contractility. Therefore, we assessed whether creatine kinase isoenzyme mRNA levels in human resistance arteries are associated with blood pressure. We isolated resistance-sized arteries from omental fat donated by consecutive women undergoing uterine fibroid surgery. Blood pressure was measured in the sitting position. Vessels of 13 women were included, 6 normotensive and 7 hypertensive, mean age 42.9 years (SE, 1.6) and mean systolic/diastolic blood pressure, 144.8 (8.0)/86.5 (4.3) mm Hg. Arteriolar creatine kinase isoenzyme mRNA was assessed using quantitative real-time polymerase chain reaction. Normalized creatine kinase B mRNA copy numbers, ranging from 5.2 to 24.4 (mean, 15.0; SE, 1.9), showed a near-perfect correlation with diastolic blood pressure (correlation coefficient, 0.9; 95% confidence interval, 0.6-1.0) and were well correlated with systolic blood pressure, with a 90% relative increase in resistance artery creatine kinase B mRNA in hypertensives compared with normotensives, normalized copy numbers were, respectively, 19.3 (SE, 2.0) versus 10.1 (SE, 2.1), P=0.0045. To our knowledge, this is the first direct evidence suggesting that resistance artery creatine kinase mRNA expression levels concur with blood pressure levels, almost doubling with hypertension. These findings add to the evidence that creatine kinase might be involved in the vasculature's pressor responses.

  17. Cannabidiol causes endothelium-dependent vasorelaxation of human mesenteric arteries via CB1 activation.

    Science.gov (United States)

    Stanley, Christopher P; Hind, William H; Tufarelli, Cristina; O'Sullivan, Saoirse E

    2015-09-01

    The protective effects of cannabidiol (CBD) have been widely shown in preclinical models and have translated into medicines for the treatment of multiple sclerosis and epilepsy. However, the direct vascular effects of CBD in humans are unknown. Using wire myography, the vascular effects of CBD were assessed in human mesenteric arteries, and the mechanisms of action probed pharmacologically. CBD-induced intracellular signalling was characterized using human aortic endothelial cells (HAECs). CBD caused acute, non-recoverable vasorelaxation of human mesenteric arteries with an Rmax of ∼ 40%. This was inhibited by cannabinoid receptor 1 (CB1) receptor antagonists, desensitization of transient receptor potential channels using capsaicin, removal of the endothelium, and inhibition of potassium efflux. There was no role for cannabinoid receptor-2 (CB2) receptor, peroxisome proliferator activated receptor (PPAR)γ, the novel endothelial cannabinoid receptor (CBe), or cyclooxygenase. CBD-induced vasorelaxation was blunted in males, and in patients with type 2 diabetes or hypercholesterolemia. In HAECs, CBD significantly reduced phosphorylated JNK, NFκB, p70s6 K and STAT5, and significantly increased phosphorylated CREB, ERK1/2, and Akt levels. CBD also increased phosphorylated eNOS (ser1177), which was correlated with increased levels of ERK1/2 and Akt levels. CB1 receptor antagonism prevented the increase in eNOS phosphorylation. This study shows, for the first time, that CBD causes vasorelaxation of human mesenteric arteries via activation of CB1 and TRP channels, and is endothelium- and nitric oxide-dependent. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Cardiology.

  18. Radiological assessment of the inferior alveolar artery course in human corpse mandibles

    Energy Technology Data Exchange (ETDEWEB)

    Bertl, Kristina [Medical University of Vienna, Division of Oral Surgery, Bernhard Gottlieb School of Dentistry, Vienna (Austria); Malmoe University, Department of Periodontology, Faculty of Odontology, Malmoe (Sweden); Hirtler, Lena [Medical University of Vienna, Center for Anatomy and Cell Biology, Department of Systematic Anatomy, Vienna (Austria); Dobsak, Toni [Medical University of Vienna, Division of Oral Surgery, Bernhard Gottlieb School of Dentistry, Vienna (Austria); Medical University of Vienna, Karl Donath Laboratory for Hard Tissue and Biomaterial Research, Division of Oral Surgery, Vienna (Austria); Austrian Cluster for Tissue Regeneration, Vienna (Austria); Heimel, Patrick [Medical University of Vienna, Karl Donath Laboratory for Hard Tissue and Biomaterial Research, Division of Oral Surgery, Vienna (Austria); Austrian Cluster for Tissue Regeneration, Vienna (Austria); Ludwig Boltzmann Institute for Clinical and Experimental Traumatology, Vienna (Austria); Gahleitner, Andre [Medical University of Vienna, Division of Oral Surgery, Bernhard Gottlieb School of Dentistry, Vienna (Austria); Medical University of Vienna, Department of Diagnostic Radiology, Division of Osteoradiology, General Hospital, Vienna (Austria); Ulm, Christian [Medical University of Vienna, Division of Oral Surgery, Bernhard Gottlieb School of Dentistry, Vienna (Austria); Plenk, Hanns [Medical University of Vienna, Bone and Biomaterials Research, Institute for Histology and Embryology, Vienna (Austria)

    2015-04-01

    CT assessment of the entire course of the inferior alveolar artery (IAA) within the mandibular canal. After contrast medium injection (180 or 400 mg/ml iodine concentration) into the external carotid arteries of 15 fresh human cadaver heads, the main IAA's position in the canal (cranial, buccal, lingual or caudal) was assessed in dental CT images of partially edentulous mandibles. The course of the main IAA could be followed at both iodine concentrations. The higher concentration gave the expected better contrast, without creating artefacts, and improved visibility of smaller arteries, such as anastomotic sections, dental branches and the incisive branch. The main IAA changed its position in the canal more often than so far known (mean 4.3 times, SD 1.24, range 2-7), but with a similar bilateral course. A cranial position was most often detected (42 %), followed by lingual (36 %), caudal (16 %) and buccal (6 %). With this non-invasive radiologic method, the entire course of the main IAA in the mandibular canal could be followed simultaneously with other bone structures on both sides of human cadaver mandibles. This methodology allows one to amend existing anatomical and histological data, which are important for surgical interventions near the mandibular canal. (orig.)

  19. The Effect of Creatine Kinase Inhibition on Contractile Properties of Human Resistance Arteries.

    Science.gov (United States)

    Taherzadeh, Zhila; Karamat, Fares A; Ankum, Willem M; Clark, Joseph F; van Montfrans, Gert A; van Bavel, Ed; Brewster, Lizzy M

    2016-02-01

    Creatine kinase (CK) is a main predictor of blood pressure, and this is thought to largely depend on high resistance artery contractility. We previously reported an association between vascular contractility and CK in normotensive pregnancy, but pregnancy is a strong CK inducer, and data on human hypertension are lacking. Therefore, we further explored CK-dependency of vascular contractility outside the context of pregnancy in normotensive and hypertensive women. Nineteen consecutive women, mean age 42 years (SE 1.3), mean systolic/diastolic blood pressure respectively 142.6 (SE 5.9)/85.6 (3.4) mm Hg (9 hypertensive), donated an omental fat sample during abdominal surgery. We compared vasodilation after the specific CK inhibitor 2,4-dinitro-1-fluorobenzene (DNFB; 10(-6) mol/l) to sodium nitroprusside (10(-6) mol/l) in isolated resistance arteries using a wire myograph. Additionally, we assessed predictors of vasoconstrictive force. DNFB reduced vascular contractility to 24.3% (SE 4.4), P resistance artery contractility across human normotension and primary hypertension outside the context of pregnancy. Further studies should explore the effect of CK inhibitors on clinical blood pressure. © American Journal of Hypertension, Ltd 2015. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Compliant Wall Simulation of a Healthy Carotid Bifurcation

    Science.gov (United States)

    Williamson, Shobha; Rayz, Vitaliy; Saloner, David; Berger, Stanley

    2003-11-01

    Cardiovascular disease is a major cause of mortality in the industrialized world. Together with the genetic causes of this disease, fluid-structure interaction (FSI) in the arterial system plays a role in the development of arteriosclerosis. In an effort to further understand this disease, an FSI model of the carotid artery is in progress. To construct this model, we begin with compliant arterial wall deformation considered under transient global blood pressure. Vessel walls are composed of collagen fibers, elastin, smooth muscle, and water. Due to its complexity and variation among humans, it is difficult to create an accurate mechanical description of this material. Hence, we begin by way of isotropic properties with the future intent of anisotropic modeling. Using these parameters, a pulsatile 3D model of wall movement for a healthy carotid artery is presented. Supported under a National Science Foundation Graduate Research Fellowship, NIH Grant HL61823, and PBD, Inc.

  1. Phosphodiesterase type 4 expression and anti-proliferative effects in human pulmonary artery smooth muscle cells

    Directory of Open Access Journals (Sweden)

    Afzal Saliha

    2006-01-01

    Full Text Available Abstract Background Pulmonary arterial hypertension is a proliferative vascular disease, characterized by aberrant regulation of smooth muscle cell proliferation and apoptosis in distal pulmonary arteries. Prostacyclin (PGI2 analogues have anti-proliferative effects on distal human pulmonary artery smooth muscle cells (PASMCs, which are dependent on intracellular cAMP stimulation. We therefore sought to investigate the involvement of the main cAMP-specific enzymes, phosphodiesterase type 4 (PDE4, responsible for cAMP hydrolysis. Methods Distal human PASMCs were derived from pulmonary arteries by explant culture (n = 14, passage 3–12. Responses to platelet-derived growth factor-BB (5–10 ng/ml, serum, PGI2 analogues (cicaprost, iloprost and PDE4 inhibitors (roflumilast, rolipram, cilomilast were determined by measuring cAMP phosphodiesterase activity, intracellular cAMP levels, DNA synthesis, apoptosis (as measured by DNA fragmentation and nuclear condensation and matrix metalloproteinase-2 and -9 (MMP-2, MMP-9 production. Results Expression of all four PDE4A-D genes was detected in PASMC isolates. PDE4 contributed to the main proportion (35.9 ± 2.3%, n = 5 of cAMP-specific hydrolytic activity demonstrated in PASMCs, compared to PDE3 (21.5 ± 2.5%, PDE2 (15.8 ± 3.4% or PDE1 activity (14.5 ± 4.2%. Intracellular cAMP levels were increased by PGI2 analogues and further elevated in cells co-treated with roflumilast, rolipram and cilomilast. DNA synthesis was attenuated by 1 μM roflumilast (49 ± 6% inhibition, rolipram (37 ± 6% and cilomilast (30 ± 4% and, in the presence of 5 nM cicaprost, these compounds exhibited EC50 values of 4.4 (2.6–6.1 nM (Mean and 95% confidence interval, 59 (36–83 nM and 97 (66–130 nM respectively. Roflumilast attenuated cell proliferation and gelatinase (MMP-2 and MMP-9 production and promoted the anti-proliferative effects of PGI2 analogues. The cAMP activators iloprost and forskolin also induced apoptosis

  2. [The stimulation of human pulmonary artery endothelial cells by cigarette smoke extract contributed to cell senescence and induced human pulmonary artery smooth cell migration].

    Science.gov (United States)

    Cai, L; Zhu, P C; Wang, Y E; Gao, Y T; Ao, Q L

    2017-06-12

    Objective: To observe the senescent effect of human pulmonary arterial endothelial cells (HPAEC) stimulated by cigarette smoke extract (CSE) and the effect of secretion of senescent cells on human pulmonary arterial smooth muscles cell (HPASMC) proliferation and migration. Methods: HPAEC was treated with different concentrations of CSE in vitro and cell proliferation was determined by CCK8, senescence cells analyzed by detecting the β-gal activity, and the senescent proteins of cells measured by Western blot. The concentration of senescence-associated secretory phenotype (SASP) was detected by ELISA and the expression of MCP-1 and TGF-β1 was measured by Real-time PCR. The number of the proliferated cells was measured by Transwell assay and immunoflurescence. Results: The HPAEC was aging with the stimulation concentration of CSE increasing and the stimulation time prolonging (Pcells increased as the exposure time prolonged. Compared with the control group, cell viability of 48 h group(1.8±0.1) and 72 h group (1.8±0.1) decreased significantly. The flow cytometry showed a significant difference between the CSE group(14.1±1.2) and the control group(28.5±1.8) in S phase(Pcell cycle arrest. The SASP was increasing as the CSE-exposure prolonged. Compared with the control group(177±39), the 48 h group(460±43) and the 72 h group(609±64) showed a marked increase in MCP-1(Pcells could secrete SASP which induced HPASMC proliferation. After different times of conditioned medium stimulation, HPASMC proliferated especially at 72 h(P<0.05) . The immnoflorescence and Transwell assay confirmed this finding. Conclusion: CSE could induce senescence of HPAEC and SASP production which improved HPASMC proliferation and migration.

  3. High Central Aortic Rather than Brachial Blood Pressure is Associated with Carotid Wall Remodeling and Increased Arterial Stiffness in Childhood.

    Science.gov (United States)

    Peluso, Gonzalo; García-Espinosa, Victoria; Curcio, Santiago; Marota, Marco; Castro, Juan; Chiesa, Pedro; Giachetto, Gustavo; Bia, Daniel; Zócalo, Yanina

    2017-03-01

    In adults, central blood pressure (cBP) is reported to associate target organ damages (TODs) rather than peripheral blood pressure (pBP). However, data regarding the association of pre-clinical TODs with cBP and pBP in pediatric populations are scarce. To evaluate in children and adolescents the importance of cBP and pBP levels, in terms of their association with hemodynamic and vascular changes. 315 subjects [age (mean/range) 12/8-18 years] were included. pBP (oscillometry, Omron-HEM433INT and Mobil-O-Graph), cBP levels and waveforms (oscillometry, Mobil-O-Graph; applanation tonometry, SphygmoCor), aortic wave reflection-related parameters, carotid intima-media thickness (CIMT) and carotid (elastic modulus, stiffness-index) and aortic stiffness (carotid-femoral pulse wave velocity, PWV). Four groups were defined considering pBP and cBP percentiles (th): cBP ≥90th, cBP blood pressure (cBP or pBP). Subgroups were matched for anthropometric and cardiovascular risk factors (propensity matching-score). Subjects with high cBP showed a worse cardiovascular risk profile in addition to worse peripheral hemodynamic conditions. The CIMT, carotid and aortic stiffness levels were also higher in those subjects. CIMT and carotid stiffness remained statistically higher when subjects were matched for pBP and other cardiovascular risk factors. There were no differences in arterial properties when subjects were analyzed (compared) considering similar pBP levels, during normal and high cBP conditions. Compared with pBP, the cBP levels show a greater association with vascular alterations (high CIMT and arterial stiffness), in children and adolescents.

  4. Modelos constitutivos para paredes arteriales, descripción del movimiento y estado de deformación//Constitutive models for arterial walls, description of movement and state of deformation

    Directory of Open Access Journals (Sweden)

    Diana Otero‐Martínez

    2014-08-01

    Full Text Available Las paredes arteriales son uno de los tejidos blandos encontrados en los seres vivos. Tienen como características ser no lineales, incompresibles y anisotrópicos. En los últimos años se han desarrollado un conjunto de modelos constitutivos que consideran un material hiperelástico. Algunos de estos modelos consideran isotropía del material pero han demostrado no ser adecuados paramodelar el comportamiento de arterias sanas. Los modelos más difundidos en este sentido consideran el material anisotrópico debido a la organización de las fibras de colágeno y a pesar de haber sido formulados para describir la conducta arterial pueden ser utilizados para representar el comportamiento de otros tejidos blandos como la vena cava infra-renal, la pared intestinal, las propiedades mecánicas del esófago, entre otros. Algunos autores incluso los han utilizado para modelar también el daño en las arterias.Palabras claves: modelo constitutivo, tejido arterial, elasticidad, pared aortica, análisis de tensiones, respuesta pasiva._________________________________________________________________________________AbstractArterial walls are one of the soft tissues found in living organism. They are non lineal, incompressible and anisotropic. A set of constitutive models have been developed considering a hyperelastic material. Some of these models consider material isotropy but they have proved to be inadequate for modeling healthy arterial behavior. Mostly used models consider the anisotropic material due to the collagens fibers and nevertheless they have been created to describe arterial behavior can be also used for modeling different soft tissue behavior as infrarenal vena cava, intestine wall, mechanical properties of the esophagus, among others. General author have used them for modeling arterial damage.Key words: constitutive modelling, arterial tissue, elasticity, aortic wall, stress análisis, passive response.

  5. Nitinol Stent Fatigue in a Peripheral Human Artery Subjected to Pulsatile and Articulation Loading

    Science.gov (United States)

    Harvey, Sean Michael

    2011-07-01

    Nitinol self-expanding stents are used to treat peripheral occluded vessels such as the superficial femoral artery or the carotid. The complex vessel articulation requires a stent device that is flexible and kink resistant yet durable. The present study shows how the latest advances in commercially available engineering software tools permit engineering simulations of the many aspects of the Nitinol stent design and analysis. Two stent geometries are evaluated: a helical type stent design, and a more traditional straight strut, with multiple crowns design. The fatigue performance of the two stents is compared. The results show that advanced nonlinear finite element simulations and fatigue predictions of the Nitinol stent are possible today inside realistic simulated human arteries. The finite element analysis software used in this study is SimXpert, Marc, and Mentat (MSC Software, Santa Ana, CA).

  6. Impaired glucose-induced thermogenesis and arterial norepinephrine response persist after weight reduction in obese humans

    DEFF Research Database (Denmark)

    Astrup, A; Andersen, T; Christensen, N J;

    1990-01-01

    A reduced thermic response and an impaired activation of the sympathetic nervous system (SNS) has been reported after oral glucose in human obesity. It is, however, not known whether the reduced SNS activity returns to normal along with weight reduction. The thermic effect of glucose was lower...... in eight obese patients than in matched control subjects (1.7% vs 9.2%, p less than 0.002). The increase in arterial norepinephrine after glucose was also blunted in the obese patients. After a 30-kg weight loss their glucose and lipid profiles were markedly improved but the thermic effect of glucose...... was still lower than that of the control subjects (4.2%, p less than 0.001). The glucose-induced arterial norepinephrine response remained diminished in the reduced obese patients whereas the changes in plasma epinephrine were similar in all three groups. The results suggest that a defective SNS may...

  7. Recognition and degradation of plant cell wall polysaccharides by two human gut symbionts.

    Directory of Open Access Journals (Sweden)

    Eric C Martens

    2011-12-01

    Full Text Available Symbiotic bacteria inhabiting the human gut have evolved under intense pressure to utilize complex carbohydrates, primarily plant cell wall glycans in our diets. These polysaccharides are not digested by human enzymes, but are processed to absorbable short chain fatty acids by gut bacteria. The Bacteroidetes, one of two dominant bacterial phyla in the adult gut, possess broad glycan-degrading abilities. These species use a series of membrane protein complexes, termed Sus-like systems, for catabolism of many complex carbohydrates. However, the role of these systems in degrading the chemically diverse repertoire of plant cell wall glycans remains unknown. Here we show that two closely related human gut Bacteroides, B. thetaiotaomicron and B. ovatus, are capable of utilizing nearly all of the major plant and host glycans, including rhamnogalacturonan II, a highly complex polymer thought to be recalcitrant to microbial degradation. Transcriptional profiling and gene inactivation experiments revealed the identity and specificity of the polysaccharide utilization loci (PULs that encode individual Sus-like systems that target various plant polysaccharides. Comparative genomic analysis indicated that B. ovatus possesses several unique PULs that enable degradation of hemicellulosic polysaccharides, a phenotype absent from B. thetaiotaomicron. In contrast, the B. thetaiotaomicron genome has been shaped by increased numbers of PULs involved in metabolism of host mucin O-glycans, a phenotype that is undetectable in B. ovatus. Binding studies of the purified sensor domains of PUL-associated hybrid two-component systems in conjunction with transcriptional analyses demonstrate that complex oligosaccharides provide the regulatory cues that induce PUL activation and that each PUL is highly specific for a defined cell wall polymer. These results provide a view of how these species have diverged into different carbohydrate niches by evolving genes that target

  8. Sox10 expressing cells in the lateral wall of the aged mouse and human cochlea.

    Directory of Open Access Journals (Sweden)

    Xinping Hao

    Full Text Available Age-related hearing loss (presbycusis is a common human disorder, affecting one in three Americans aged 60 and over. Previous studies have shown that presbyacusis is associated with a loss of non-sensory cells in the cochlear lateral wall. Sox10 is a transcription factor crucial to the development and maintenance of neural crest-derived cells including some non-sensory cell types in the cochlea. Mutations of the Sox10 gene are known to cause various combinations of hearing loss and pigmentation defects in humans. This study investigated the potential relationship between Sox10 gene expression and pathological changes in the cochlear lateral wall of aged CBA/CaJ mice and human temporal bones from older donors. Cochlear tissues prepared from young adult (1-3 month-old and aged (2-2.5 year-old mice, and human temporal bone donors were examined using quantitative immunohistochemical analysis and transmission electron microscopy. Cells expressing Sox10 were present in the stria vascularis, outer sulcus and spiral prominence in mouse and human cochleas. The Sox10(+ cell types included marginal and intermediate cells and outer sulcus cells, including those that border the scala media and those extending into root processes (root cells in the spiral ligament. Quantitative analysis of immunostaining revealed a significant decrease in the number of Sox10(+ marginal cells and outer sulcus cells in aged mice. Electron microscopic evaluation revealed degenerative alterations in the surviving Sox10(+ cells in aged mice. Strial marginal cells in human cochleas from donors aged 87 and older showed only weak immunostaining for Sox10. Decreases in Sox10 expression levels and a loss of Sox10(+ cells in both mouse and human aged ears suggests an important role of Sox10 in the maintenance of structural and functional integrity of the lateral wall. A loss of Sox10(+ cells may also be associated with a decline in the repair capabilities of non-sensory cells in the

  9. Quantifying turbulent wall shear stress in a subject specific human aorta using large eddy simulation.

    Science.gov (United States)

    Lantz, Jonas; Gårdhagen, Roland; Karlsson, Matts

    2012-10-01

    In this study, large-eddy simulation (LES) is employed to calculate the disturbed flow field and the wall shear stress (WSS) in a subject specific human aorta. Velocity and geometry measurements using magnetic resonance imaging (MRI) are taken as input to the model to provide accurate boundary conditions and to assure the physiological relevance. In total, 50 consecutive cardiac cycles were simulated from which a phase average was computed to get a statistically reliable result. A decomposition similar to Reynolds decomposition is introduced, where the WSS signal is divided into a pulsating part (due to the mass flow rate) and a fluctuating part (originating from the disturbed flow). Oscillatory shear index (OSI) is plotted against time-averaged WSS in a novel way, and locations on the aortic wall where elevated values existed could easily be found. In general, high and oscillating WSS values were found in the vicinity of the branches in the aortic arch, while low and oscillating WSS were present in the inner curvature of the descending aorta. The decomposition of WSS into a pulsating and a fluctuating part increases the understanding of how WSS affects the aortic wall, which enables both qualitative and quantitative comparisons.

  10. Arterial Stiffness.

    Science.gov (United States)

    Avolio, Alberto

    2013-04-01

    Stiffness of large arteries has been long recognized as a significant determinant of pulse pressure. However, it is only in recent decades, with the accumulation of longitudinal data from large and varied epidemiological studies of morbidity and mortality associated with cardiovascular disease, that it has emerged as an independent predictor of cardiovascular risk. This has generated substantial interest in investigations related to intrinsic causative and associated factors responsible for the alteration of mechanical properties of the arterial wall, with the aim to uncover specific pathways that could be interrogated to prevent or reverse arterial stiffening. Much has been written on the haemodynamic relevance of arterial stiffness in terms of the quantification of pulsatile relationships of blood pressure and flow in conduit arteries. Indeed, much of this early work regarded blood vessels as passive elastic conduits, with the endothelial layer considered as an inactive lining of the lumen and as an interface to flowing blood. However, recent advances in molecular biology and increased technological sophistication for the detection of low concentrations of biochemical compounds have elucidated the highly important regulatory role of the endothelial cell affecting vascular function. These techniques have enabled research into the interaction of the underlying passive mechanical properties of the arterial wall with the active cellular and molecular processes that regulate the local environment of the load-bearing components. This review addresses these emerging concepts.

  11. An Human-Computer Interactive Augmented Reality System for Coronary Artery Diagnosis Planning and Training.

    Science.gov (United States)

    Li, Qiming; Huang, Chen; Lv, Shengqing; Li, Zeyu; Chen, Yimin; Ma, Lizhuang

    2017-09-02

    In order to let the doctor carry on the coronary artery diagnosis and preoperative planning in a more intuitive and more natural way, and to improve the training effect for interns, an augmented reality system for coronary artery diagnosis planning and training (ARS-CADPT) is designed and realized in this paper. At first, a 3D reconstruction algorithm based on computed tomographic (CT) images is proposed to model the coronary artery vessels (CAV). Secondly, the algorithms of static gesture recognition and dynamic gesture spotting and recognition are presented to realize the real-time and friendly human-computer interaction (HCI), which is the characteristic of ARS-CADPT. Thirdly, a Sort-First parallel rendering and splicing display subsystem is developed, which greatly expands the capacity of student users. The experimental results show that, with the use of ARS-CADPT, the reconstruction accuracy of CAV model is high, the HCI is natural and fluent, and the visual effect is good. In a word, the system fully meets the application requirement.

  12. Gene expression profiling in the human middle cerebral artery after cerebral ischemia

    DEFF Research Database (Denmark)

    Vikman, P; Edvinsson, L

    2006-01-01

    MCA samples distributing to the ischemic area, 7-10 days post-stroke. The gene expression was examined with real-time polymerase chain reaction (PCR) and microarray, proteins were studied with immunohistochemistry. We investigated genes previously shown to be upregulated in animal models of cerebral...... with microarray and seven genes chosen for further investigation with real-time PCR; ELK3, LY64, Metallothionin IG, POU3F4, Actin alpha2, RhoA and smoothelin. Six of these were regulated the same way when confirming array expression with real-time PCR. Gene expression studies in the human MCA leading......We have investigated the gene expression in human middle cerebral artery (MCA) after ischemia. Ischemic stroke affects the perfusion in the affected area and experimental cerebral ischemia results in upregulation of vasopressor receptors in the MCA leading to the ischemic area. We obtained human...

  13. Toxicology Study of Single-walled Carbon Nanotubes and Reduced Graphene Oxide in Human Sperm

    Science.gov (United States)

    Asghar, Waseem; Shafiee, Hadi; Velasco, Vanessa; Sah, Vasu R.; Guo, Shirui; El Assal, Rami; Inci, Fatih; Rajagopalan, Adhithi; Jahangir, Muntasir; Anchan, Raymond M.; Mutter, George L.; Ozkan, Mihrimah; Ozkan, Cengiz S.; Demirci, Utkan

    2016-08-01

    Carbon-based nanomaterials such as single-walled carbon nanotubes and reduced graphene oxide are currently being evaluated for biomedical applications including in vivo drug delivery and tumor imaging. Several reports have studied the toxicity of carbon nanomaterials, but their effects on human male reproduction have not been fully examined. Additionally, it is not clear whether the nanomaterial exposure has any effect on sperm sorting procedures used in clinical settings. Here, we show that the presence of functionalized single walled carbon nanotubes (SWCNT-COOH) and reduced graphene oxide at concentrations of 1–25 μg/mL do not affect sperm viability. However, SWCNT-COOH generate significant reactive superoxide species at a higher concentration (25 μg/mL), while reduced graphene oxide does not initiate reactive species in human sperm. Further, we demonstrate that exposure to these nanomaterials does not hinder the sperm sorting process, and microfluidic sorting systems can select the sperm that show low oxidative stress post-exposure.

  14. DNA methylation changes in human lung epithelia cells exposed to multi-walled carbon nanotubes.

    Science.gov (United States)

    Sierra, Marta I; Rubio, Laura; Bayón, Gustavo F; Cobo, Isabel; Menendez, Pablo; Morales, Paula; Mangas, Cristina; Urdinguio, Rocio G; Lopez, Virginia; Valdes, Adolfo; Vales, Gerard; Marcos, Ricard; Torrecillas, Ramon; Fernández, Agustin F; Fraga, Mario F

    2017-09-13

    Humans are increasingly exposed to nanoparticles and, although many of their physiological effects have been described, the molecular mechanisms underlying them are still largely unknown. The present study aimed to determine the possible role of certain epigenetic mechanisms in the cellular response of human lung epithelial cells that are triggered by long-term exposure to titanium dioxide nanoparticles (TiO2NPs) and multi-walled carbon nanotubes (MWCNTs). The results showed that exposure to TiO2NPs had only minor effects on genome-wide DNA methylation. However, we identified 755 CpG sites showing consistent DNA hypomethylation in cells exposed to MWCNTs. These sites were mainly located at low density CpG regions and enhancers, and very frequently on the X chromosome. Our results thus suggest that long-term MWCNT exposure may have important effects on the epigenome.

  15. Ischemic heart disease induces upregulation of endothelin receptor mRNA in human coronary arteries

    DEFF Research Database (Denmark)

    Wackenfors, Angelica; Emilson, Malin; Ingemansson, Richard;

    2004-01-01

    and controls using real-time polymerase chain reaction (real-time PCR). In addition, the suitability of organ culture as a model mimicking endothelin receptor changes in cardiovascular disease was evaluated by in vitro pharmacology and real-time PCR. Endothelin ETA and ETB receptor mRNA levels were......Endothelin has been implicated in the pathogenesis of ischemic heart disease and congestive heart failure. The aims were to quantify endothelin type A (ETA) and type B (ETB) receptor mRNA levels in human coronary arteries from patients with ischemic heart disease, congestive heart failure...

  16. Differential localization and characterization of functional calcitonin gene-related peptide receptors in human subcutaneous arteries

    DEFF Research Database (Denmark)

    Edvinsson, L; Ahnstedt, H; Larsen, R;

    2014-01-01

    Calcitonin gene-related peptide (CGRP) and its receptor are widely distributed within the circulation and the mechanism behind its vasodilation not only differs from one animal species to another but is also dependent on the type and size of vessel. The present study examines the nature of CGRP......-induced vasodilation, characteristics of the CGRP receptor antagonist telcagepant and localization of the key components calcitonin receptor-like receptor (CLR) and receptor activity modifying protein 1 (RAMP1) of the CGRP receptor in human subcutaneous arteries....

  17. Long-term effects of biodegradable versus durable polymer-coated sirolimus-eluting stents on coronary arterial wall morphology assessed by virtual histology intravascular ultrasound

    Institute of Scientific and Technical Information of China (English)

    LIU Hui-liang; ZHANG Jiao; JIN Zhi-geng; LUO Jian-ping; MA Dong-xing; YANG Sheng-li; LIU Ying; HAN Wei; JING Li-min; MENG Rong-ying

    2011-01-01

    Background The durable presence of polymer coating on drug-eluting stent (DES) surface may be one of the principal reasons for stent thrombosis. The long-term coronary arterial response to biodegradable polymer-coated sirolimus-eluting stent (BSES) in vivo remained unclear.Methods Forty-one patients were enrolled in this study and virtual histology intravascular ultrasound (VH-IVUS) was performed to assess the native artery vascular responses to BSES compared with durable polymer-coated SES (DSES) during long-term follow-up (median: 8 months). The incidence of necrotic core abutting to the lumen was evaluated at follow-up.Results With similar in-stent late luminal loss (0.15 mm (0.06-0.30 mm) vs. 0.19 mm (0.03-0.30 mm), P=0.772), the overall incidence of necrotic core abutting to the lumen was significantly less in BSES group than in DSES group (44% vs.63%, P <0.05) (proximal 18%, stented site 14% and distal 12% in BSES group, proximal 19%, stented site 28% and distal 16% in DSES group). The DSES-treated segments had a significant higher incidence of necrotic core abutting to the lumen through the stent struts (73% vs. 36%, P <0.01). In addition, more multiple necrotic core abutting to the lumen was observed in DSES group (overall: 63% vs. 36%, P <0.05). Furthermore, when the stented segments with necrotic core abutting to the lumen had been taken into account only, DSES-treated lesions tended to contain more multiple necrotic core abutting to the lumen through the stent struts than BSES-treated lesions (74% vs. 33%), although there was no statistically significant difference between them (P=0.06).Conclusions By VH-IVUS analysis at follow-up, a greater frequency of stable lesion morphometry was shown in lesions treated with BSESs compared with lesions treated with DSESs. The major reason was BSES produced less toxicity to the arterial wall and facilitated neointimal healing as a result of polymer coating on DES surface biodegraded as time went by.

  18. Real-time ultrasound-tagging to track the 2D motion of the common carotid artery wall in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Zahnd, Guillaume, E-mail: g.zahnd@erasmusmc.nl [Biomedical Imaging Group Rotterdam, Departments of Radiology and Medical Informatics, Erasmus MC, Rotterdam 3000 CA (Netherlands); Salles, Sébastien; Liebgott, Hervé; Vray, Didier [Université de Lyon, CREATIS, CNRS UMR 5220, INSERM U1044, INSA-Lyon, Université Lyon 1, Lyon 69100 (France); Sérusclat, André [Department of Radiology, Louis Pradel Hospital, Lyon 69500 (France); Moulin, Philippe [Department of Endocrinology, Louis Pradel Hospital, Hospices Civils de Lyon, Université Lyon 1, Lyon 69100, France and INSERM UMR 1060, Lyon 69500 (France)

    2015-02-15

    Purpose: Tracking the motion of biological tissues represents an important issue in the field of medical ultrasound imaging. However, the longitudinal component of the motion (i.e., perpendicular to the beam axis) remains more challenging to extract due to the rather coarse resolution cell of ultrasound scanners along this direction. The aim of this study is to introduce a real-time beamforming strategy dedicated to acquire tagged images featuring a distinct pattern in the objective to ease the tracking. Methods: Under the conditions of the Fraunhofer approximation, a specific apodization function was applied to the received raw channel data, in real-time during image acquisition, in order to introduce a periodic oscillations pattern along the longitudinal direction of the radio frequency signal. Analytic signals were then extracted from the tagged images, and subpixel motion tracking of the intima–media complex was subsequently performed offline, by means of a previously introduced bidimensional analytic phase-based estimator. Results: The authors’ framework was applied in vivo on the common carotid artery from 20 young healthy volunteers and 6 elderly patients with high atherosclerosis risk. Cine-loops of tagged images were acquired during three cardiac cycles. Evaluated against reference trajectories manually generated by three experienced analysts, the mean absolute tracking error was 98 ± 84 μm and 55 ± 44 μm in the longitudinal and axial directions, respectively. These errors corresponded to 28% ± 23% and 13% ± 9% of the longitudinal and axial amplitude of the assessed motion, respectively. Conclusions: The proposed framework enables tagged ultrasound images of in vivo tissues to be acquired in real-time. Such unconventional beamforming strategy contributes to improve tracking accuracy and could potentially benefit to the interpretation and diagnosis of biomedical images.

  19. Endovascular repair of arterial iliac vessel wall lesions with a self-expandable nitinol stent graft system.

    Directory of Open Access Journals (Sweden)

    Birger Mensel

    Full Text Available OBJECTIVE: To assess the therapeutic outcome after endovascular repair of iliac arterial lesions (IALs using a self-expandable Nitinol stent graft system. METHODS: Between July 2006 and March 2013, 16 patients (13 males, mean age: 68 years with a self-expandable Nitinol stent graft. A total of 19 lesions were treated: nine true aneurysms, two anastomotic aneurysms, two dissections, one arteriovenous fistula, two type 1B endoleaks after endovascular aneurysm repair, one pseudoaneurysm, and two perforations after angioplasty. Pre-, intra-, and postinterventional imaging studies and the medical records were analyzed for technical and clinical success and postinterventional complications. RESULTS: The primary technical and clinical success rate was 81.3% (13/16 patients and 75.0% (12/16, respectively. Two patients had technical failure due to persistent type 1A endoleak and another patient due to acute stent graft thrombosis. One patient showed severe stent graft kinking on the first postinterventional day. In two patients, a second intervention was performed. The secondary technical and clinical success rate was 87.5% (14/16 and 93.8% (15/16. The minor complication rate was 6.3% (patient with painful hematoma at the access site. The major complication rate was 6.3% (patient with ipsilateral deep vein thrombosis. During median follow-up of 22.4 months, an infection of the aneurysm sac in one patient and a stent graft thrombosis in another patient were observed. CONCLUSION: Endovascular repair of various IALs with a self-expandable Nitinol stent graft is safe and effective.

  20. Effects of pressure-dependent segmental arterial compliance and postural changes on pulse wave transmission in an arterial model of the human upper limb.

    Science.gov (United States)

    Xu, Ke; Butlin, Mark; Avolio, Alberto P

    2011-01-01

    With increasing interest in the effect of postural changes on arterial blood pressure and vascular properties, it is important to understand effects of pressure-dependent arterial compliance. This study investigates effects of pressure-dependent compliance on pulse wave velocity (PWVar), pressure wave shape, and transmission characteristics in an arterial model of the human arm from heart to radial artery from supine to standing. Estimated central pressure waveform was used as the input for the model, calculated using a validated transfer function (SphygmoCor, AtCor Medical) from recorded radial pulses in 10 healthy male subjects (53.8 ± 7.9 years) during 0, 30, 60 and 90 degree head-up tilt. A 5-segment linear model was optimized using estimated central and recorded radial arterial pulse; each segment represented by an equivalent inductance, resistance and capacitance (compliance (C)) Pressure-dependent compliance (C(P)=a · e(b · P) was added to develop a nonlinear model, and the radial pulse calculated. Comparison of the radial pulse calculated by the linear and nonlinear models showed no statistical difference in systolic, diastolic, mean, and pulse pressure in any position of tilt. However, waveform shape was increasingly divergent at higher angles of tilt (RMS error 2.3 ± 1.2 mmHg supine, 6.5 ± 3.0 mmHg standing) as was PWVar (0% increase from supine to standing in the linear model, 16.7% increase in nonlinear model). Fourier analysis demonstrated peak amplitude of transmission being at higher frequencies and phase delay being lower in the nonlinear model relative to the linear model. Pressure-dependent arterial compliance, whilst having no effect on peak values of pressure, has significant effects on waveform shape and transmission speed, especially with a more upright position.

  1. Arterial flow regulator enables transplantation and growth of human fetal kidneys in rats.

    Science.gov (United States)

    Chang, N K; Gu, J; Gu, S; Osorio, R W; Concepcion, W; Gu, E

    2015-06-01

    Here we introduce a novel method of transplanting human fetal kidneys into adult rats. To overcome the technical challenges of fetal-to-adult organ transplantation, we devised an arterial flow regulator (AFR), consisting of a volume adjustable saline-filled cuff, which enables low-pressure human fetal kidneys to be transplanted into high-pressure adult rat hosts. By incrementally withdrawing saline from the AFR over time, blood flow entering the human fetal kidney was gradually increased until full blood flow was restored 30 days after transplantation. Human fetal kidneys were shown to dramatically increase in size and function. Moreover, rats which had all native renal mass removed 30 days after successful transplantation of the human fetal kidney were shown to have a mean survival time of 122 days compared to 3 days for control rats that underwent bilateral nephrectomy without a prior human fetal kidney transplant. These in vivo human fetal kidney models may serve as powerful platforms for drug testing and discovery.

  2. Human chest wall function while awake and during halothane anesthesia. I. Quiet breathing.

    Science.gov (United States)

    Warner, D O; Warner, M A; Ritman, E L

    1995-01-01

    Data concerning chest wall configuration and the activities of the major respiratory muscles that determine this configuration during anesthesia in humans are limited. The aim of this study was to determine the effects of halothane anesthesia on respiratory muscle activity and chest wall shape and motion during spontaneous breathing. Six human subjects were studied while awake and during 1 MAC halothane anesthesia. Respiratory muscle activity was measured using fine-wire electromyography electrodes. Chest wall configuration was determined using images of the thorax obtained by three-dimensional fast computed tomography. Tidal changes in gas volume were measured by integrating respiratory gas flow, and the functional residual capacity was measured by a nitrogen dilution technique. While awake, ribcage expansion was responsible for 25 +/- 4% (mean +/- SE) of the total change in thoracic volume (delta Vth) during inspiration. Phasic inspiratory activity was regularly present in the diaphragm and parasternal intercostal muscles. Halothane anesthesia (1 MAC) abolished activity in the parasternal intercostal muscles and increased phasic expiratory activity in the abdominal muscles and lateral ribcage muscles. However, halothane did not significantly change the ribcage contribution to delta Vth (18 +/- 4%). Intrathoracic blood volume, measured by comparing changes in total thoracic volume and gas volume, increased significantly during inspiration both while awake and while anesthetized (by approximately 20% of delta Vth, P < 0.05). Halothane anesthesia significantly reduced the functional residual capacity (by 258 +/- 78 ml), primarily via an inward motion of the end-expiratory position of the ribcage. Although the diaphragm consistently changed shape, with a cephalad displacement of posterior regions and a caudad displacement of anterior regions, the diaphragm did not consistently contribute to the reduction in the functional residual capacity. Halothane anesthesia

  3. Long-term follow-up analysis of microsurgical clip ligation and endovascular coil embolization for dorsal wall blister aneurysms of the internal carotid artery.

    Science.gov (United States)

    Brown, Mason A; Guandique, Cristian F; Parish, Jonathan; McMillan, Aubrey C; Lehnert, Stephen; Mansour, Nassir; Tu, Michael; Bohnstedt, Bradley N; Payner, Troy D; Leipzig, Thomas J; DeNardo, Andrew J; Scott, John A; Cohen-Gadol, Aaron A

    2017-05-01

    Blister aneurysms at non-branching sites of the dorsal internal carotid artery (dICA) are fragile, rare, and often difficult to treat. The purpose of this study is to address the demographics, treatment modalities, and long-term outcome of patients treated for dICA blister aneurysms. A retrospective review of medical records identified all consecutive patients who presented with a blister aneurysm from 2002 to 2011 at our institution. Eighteen patients (M=7, F=11; mean age: 48.4±15.1years; range: 15-65years) harbored a total of 43 aneurysms, 25 of which were dorsal wall blister aneurysms of the ICA. Eleven (61.1%) patients presented with aneurysmal subarachnoid hemorrhage (aSAH), and 10 (55.6%) patients had multiple aneurysms at admission. Twelve patients had 18 aneurysms that were treated microsurgically. Five (41.7%) of these patients had a single recurrence that was retreated with subsequent repeat clip ligation. Six patients had 7 blister aneurysms that were treated with endovascularly. One (16.7%) of these patients had a single recurrence that was retreated with subsequent coil embolization. Postoperative vasospasm occurred in 8 (44.4%) patients, one of whom suffered from a stroke. This is one of the largest single-institution dICA blister aneurysm studies to date. There was no detected significant difference between microsurgical clip ligation and endovascular coil embolization in terms of surgical outcome. These blister aneurysms demonstrate a propensity to be associated with multiple cerebral aneurysms. Strict clinical and angiographic long-term follow-up may be warranted. Blister aneurysms are focal wall defects covered by a thin layer of fibrous tissue and adventitia, lacking the usual collagenous layer. Due to their pathologically thin vessel wall, blister aneurysms are prone to rupture. The management of these rare and fragile aneurysms presents a number of challenges. Here, we address the long-term outcome of patients treated for blister aneurysms at

  4. Human activated protein C variants in a rat model of arterial thrombosis

    Directory of Open Access Journals (Sweden)

    Dahlbäck Björn

    2008-10-01

    Full Text Available Abstract Background Activated protein C (APC inhibits coagulation by degrading activated factor V (FVa and factor VIII (FVIIIa, protein S (PS functioning as a cofactor to APC. Methods By mutagenesis of the vitamin K-dependent Gla domain of APC, we have recently created an APC variant having enhanced anticoagulant activity due to increased affinity for negatively charged phospholipid membranes. In the present study, the potential antithrombotic effects of this APC variant, and of a variant APC that is additionally mutated in the serine protease domain, have been evaluated in a blind randomized study in a rat model of arterial thrombosis. In this model, we have previously found the combination of bovine APC and PS to be highly antithrombotic. Four treatment groups each containing 10 rats were, in a blind random fashion, given intravenous bolus injections of wild-type or mutant variants of APC (0.8 mg/kg together with human PS (0.6 mg/kg or human PS (0.6 mg/kg alone. A control group with 20 animals where given vehicle only. Results A trend to increased patency rates was noted in a group receiving one of the APC variants, but it did not reach statistical significance. Conclusion In conclusion, administration of human APC variants having enhanced anticoagulant efficacy together with human PS in a rat model of arterial thrombosis did not give an efficient antithrombotic effect. The lack of effect may be due to species-specific differences between the human protein C system and the rat hemostatic system.

  5. A Preliminary Observation of Weight Loss Following Left Gastric Artery Embolization in Humans

    Directory of Open Access Journals (Sweden)

    Andrew J. Gunn

    2014-01-01

    Full Text Available Background/Objectives. Embolization of the left gastric artery (LGA, which preferentially supplies the gastric fundus, has been shown to produce weight loss in animal models. However, weight loss after LGA embolization in humans has not been previously established. The aim of this study was to evaluate postprocedural weight loss in patients following LGA embolization. Subjects/Methods. A retrospective analysis of the medical records of patients who underwent LGA embolization for upper gastrointestinal (GI bleeding was performed. Postprocedural weight loss in this group was compared to a control group of patients who had undergone embolization of other arteries for upper GI bleeding. Results. The experimental group (N=19 lost an average of 7.3% of their initial body weight within three months of LGA embolization, which was significantly greater than the 2% weight loss observed in the control group (N=28 (P=0.006. No significant differences were seen between the groups in preprocedural body mass index (BMI, age, postprocedural care in the intensive care unit, history of malignancy, serum creatinine, or left ventricular ejection fraction. Conclusions. The current data suggest that body weight in humans may be modulated via LGA embolization. Continued research is warranted with prospective studies to further investigate this phenomenon.

  6. Investigation of CGRP receptors and peptide pharmacology in human coronary arteries. Characterization with a nonpeptide antagonist

    DEFF Research Database (Denmark)

    Hasbak, Philip; Saetrum Opgaard, Ole; Eskesen, Karen

    2003-01-01

    in human coronary arteries. Relaxant responses were studied on isolated segments of coronary arteries after precontraction with U46619 (9,11-dideoxy-11alpha,9alpha-epoxymethano-prostaglandin F(2alpha)). The human peptides alphaCGRP, AM, and amylin induced relaxation with mean pEC50 values of 8.6, 6.......8, and 6.3 M, respectively. Preincubation with alphaCGRP(8-37) (10(-7) -10(-5) M) and a novel nonpeptide CGRP antagonist "Compound 1" (WO98/11128) (10(-7)-10(-5) M) caused a dose-dependent rightward shift of the concentration-response curves for alphaCGRP with pA(2) values of 7.0 and 7.1, respectively....... Preincubation with alphaCGRP(8-37) (10(-6) M) and Compound 1 (10(-6) M) caused significant rightward shift of the concentration-response curves for AM and amylin as well with pK B values between 6.6 and 7.5. Preincubation with AM(22-52) had no antagonistic effect on the AM and amylin response, neither did...

  7. Reasonable classical concepts in human lower limb anatomy from the viewpoint of the primitive persistent sciatic artery and twisting human lower limb.

    Science.gov (United States)

    Kawashima, Tomokazu; Sasaki, Hiroshi

    2010-11-01

    The main aim of this review is (1) to introduce the two previous studies we published human lower limb anatomy based on the conventional macroscopic anatomical [corrected] criteria with hazardous recognition of this description, (2) to activate the discussion whether the limb homology exists, and (3) to contribute to future study filling the gap between the gross anatomy and embryology. One of the topics we discussed was the human persistent sciatic artery. To date, numerous human cases of persistent sciatic artery have been reported in which the anomalous artery was present in the posterior compartment of the thigh alongside the sciatic nerve. As one of the important criteria for assessing the human primitive sciatic artery, its ventral arterial position with respect to the sciatic nerve is reasonable based on the initial positional relationship between ventral arterial and dorsal nervous systems and comparative anatomical findings. We also discuss ways of considering the topography of muscles of the lower limb and their innervations compared to those of the upper limb. We propose a schema of the complex anatomical characteristics of the lower limb based on the vertebrate body plan. According to this reasonable schema, the twisted anatomy of the lower limb can be understood more easily. These two main ideas discussed in this paper will be useful for further understanding of the anatomy of the lower limb and as a first step for future. We hope that the future study in lower limb will be further developed by both viewpoints of the classical gross anatomy and recent embryology.

  8. Human chest wall function while awake and during halothane anesthesia. II. Carbon dioxide rebreathing.

    Science.gov (United States)

    Warner, D O; Warner, M A

    1995-01-01

    Changes in the distribution of respiratory drive to different respiratory muscles may contribute to respiratory depression produced by halothane. The aim of this study was to examine factors that are responsible for halothane-induced depression of the ventilatory response to carbon dioxide rebreathing. In six human subjects, respiratory muscle activity in the parasternal intercostal, abdominal, and diaphragm muscles was measured using fine-wire electromyography electrodes. Chest wall motion was determined by respiratory impedance plethysmography. Electromyography activities and chest wall motion were measured during hyperpnea produced by carbon dioxide rebreathing while the subjects were awake and during 1 MAC halothane anesthesia. Halothane anesthesia significantly reduced the slope of the response of expiratory minute ventilation to carbon dioxide (from 2.88 +/- 0.73 (mean +/- SE) to 2.01 +/- 0.45 l.min-1.mmHg-1). During the rebreathing period, breathing frequency significantly increased while awake (from 10.3 +/- 1.4 to 19.7 +/- 2.6 min-1, P awake and anesthetized in four of the six subjects. Halothane anesthesia enhances the rebreathing response of neural drive to the primary respiratory muscle, the diaphragm. These findings provide direct evidence that, at the dose examined in this study, halothane-induced respiratory depression is caused by alterations in the distribution and timing of neural drive to the respiratory muscles, rather than a global depression of respiratory motoneuron drive.

  9. Textural feature selection for enhanced detection of stationary humans in through-the-wall radar imagery

    Science.gov (United States)

    Chaddad, A.; Ahmad, F.; Amin, M. G.; Sevigny, P.; DiFilippo, D.

    2014-05-01

    Feature-based methods have been recently considered in the literature for detection of stationary human targets in through-the-wall radar imagery. Specifically, textural features, such as contrast, correlation, energy, entropy, and homogeneity, have been extracted from gray-level co-occurrence matrices (GLCMs) to aid in discriminating the true targets from multipath ghosts and clutter that closely mimic the target in size and intensity. In this paper, we address the task of feature selection to identify the relevant subset of features in the GLCM domain, while discarding those that are either redundant or confusing, thereby improving the performance of feature-based scheme to distinguish between targets and ghosts/clutter. We apply a Decision Tree algorithm to find the optimal combination of co-occurrence based textural features for the problem at hand. We employ a K-Nearest Neighbor classifier to evaluate the performance of the optimal textural feature based scheme in terms of its target and ghost/clutter discrimination capability and use real-data collected with the vehicle-borne multi-channel through-the-wall radar imaging system by Defence Research and Development Canada. For the specific data analyzed, it is shown that the identified dominant features yield a higher classification accuracy, with lower number of false alarms and missed detections, compared to the full GLCM based feature set.

  10. Long term organ culture of human prostate tissue in a NASA-designed rotating wall bioreactor

    Science.gov (United States)

    Margolis, L.; Hatfill, S.; Chuaqui, R.; Vocke, C.; Emmert-Buck, M.; Linehan, W. M.; Duray, P. H.

    1999-01-01

    PURPOSE: To maintain ex vivo integral prostatic tissue including intact stromal and ductal elements using the NASA-designed Rotating Wall Vessel (RWV) which maintains colocalized cells in an environment that promotes both three-dimensional cellular interactions together with the uniform mass transfer of nutrients and metabolic wastes. MATERIALS AND METHODS: Samples of normal prostate were obtained as a byproduct of transurethral prostatectomy or needle biopsy. Prostatic tissue dissected into small 1 x 1 mm. blocks was cultured in the Rotating Wall Vessel (RWV) Bioreactor for various time periods and analyzed using histological, immunochemical, and total cell RNA assays. RESULTS: We report the long term maintenance of benign explanted human prostate tissue grown in simple culture medium, under the simulated microgravity conditions afforded by the RWV bioreactor. Mesenchymal stromal elements including blood vessels and architecturally preserved tubuloglandular acini were maintained for a minimum of 28 days. Cytokeratins, vimentin and TGF-beta2 receptor and ligand were preserved through the entire culture period as revealed by immunocytochemistry. Prostatic acid phosphatase (PAP) was continuously expressed during the culture period, although somewhat decreased. Prostatic specific antigen (PSA) and its transcript were down regulated over time of culture. Prostatic carcinoma cells from the TSU cell line were able to invade RWV-cultured benign prostate tissue explants. CONCLUSIONS: The RWV bioreactor represents an additional new technology for culturing prostate tissue for further investigations concerning the basic physiology and pathobiology of this clinically important tissue.

  11. Focal adhesion kinase antisense oligodeoxynucleotides inhibit human pulmonary artery smooth muscle cells proliferation and promote human pulmonary artery smooth muscle cells apoptosis

    Institute of Scientific and Technical Information of China (English)

    LIN Chun-long; ZHANG Zhen-xiang; XU Yong-jian; NI Wang; CHEN Shi-xin

    2005-01-01

    Background Pulmonary artery smooth muscle cell (PASMC) proliferation plays an important role in pulmonary vessel structural remodelling. At present, the mechanisms related to proliferation of PASMCs are not clear. Focal adhesion kinase (FAK) is a widely expressed nonreceptor protein tyrosine kinase. Recent research indicates that FAK is implicated in signalling pathways which regulate cytoskeletal organization, adhesion, migration, survival and proliferation of cells. Furthermore, there are no reports about the role of FAK in human pulmonary artery smooth muscle cells (HPASMCs). We investigated whether FAK takes part in the intracellular signalling pathway involved in HPASMCs proliferation and apoptosis, by using antisense oligodeoxynucleotides (ODNs) to selectively suppress the expression of FAK protein.Methods Cultured HPASMCs stimulated by fibronectin (40 μg/ml) were passively transfected with ODNs, sense FAK, mismatch sense and antisense-FAK respectively. Expression of FAK, Jun NH2-terminal kinase (JNK), cyclin-dependent kinase 2 (CDK 2) and caspase-3 proteins were detected by immunoprecipitation and Western blots. Cell cycle and cell apoptosis were analysed by flow cytometry. In addition, cytoplasmic FAK expression was detected by immunocytochemical staining.Results When compared with mismatch sense group, the protein expressions of FAK, JNK and CDK 2 in HPASMCs decreased in antisense-FAK ODNs group and increased in sense-FAK ODNs group significantly. Caspase-3 expression upregulated in HPASMCs when treated with antisense ODNs and downregulated when treated with sense ODNs. When compared with mismatch sense ODNs group, the proportion of cells at G1 phase decreased significantly in sense ODNs group, while the proportion of cells at S phase increased significantly. In contrast, compared with mismatch sense ODNs group, the proportion of cells at G1 phase was increased significantly in antisense-FAK ODNs group. The level of cell apoptosis in antisense-FAK group

  12. Expression of ET(A) and ET(B) receptor mRNA in human cerebral arteries

    DEFF Research Database (Denmark)

    Hansen-Schwartz, J; Szok, D; Edvinsson, L

    2002-01-01

    The vascular effects of endothelins (ET) are in mammals mediated via two receptor subtypes, endothelin A (ET(A), mainly constrictive) and endothelin B (ET(B), mainly dilating) receptors. We have examined the presence of ET(A) and ET(B) receptor mRNA using the reverse transcription polymerase chain...... reaction (RT-PCR) in both normal human cerebral arteries and cerebral arteries from patients with cerebrovascular disease. Two vessel preparations were studied: macroscopic arteries and microvessels, the latter obtained through a sensitive separation method. In endothelial cells both ET(A) and ET......(B) receptor mRNA was detected. In almost all samples from normal cerebral arteries only ET(A) receptor mRNA was detected, whereas in vessel samples from patients with cerebrovascular disease as well as cerebral neoplasms, additional ET(B) receptor mRNA was detected significantly more frequently...

  13. The transcriptome of human epicardial, mediastinal and subcutaneous adipose tissues in men with coronary artery disease.

    Directory of Open Access Journals (Sweden)

    Sandra Guauque-Olarte

    Full Text Available BACKGROUND: The biological functions of epicardial adipose tissue (EAT remain largely unknown. However, the proximity of EAT to the coronary arteries suggests a role in the pathogenesis of coronary artery disease (CAD. The objectives of this study were to identify genes differentially regulated among three adipose tissues, namely EAT, mediastinal (MAT and subcutaneous (SAT and to study their possible relationships with the development of cardiovascular diseases. METHODS AND RESULTS: Samples were collected from subjects undergoing coronary artery bypass grafting surgeries. Gene expression was evaluated in the three adipose depots of six men using the Illumina® HumanWG-6 v3.0 expression BeadChips. Twenty-three and 73 genes were differentially up-regulated in EAT compared to MAT and SAT, respectively. Ninety-four genes were down-regulated in EAT compared to SAT. However, none were significantly down-regulated in EAT compared to MAT. More specifically, the expression of the adenosine A1 receptor (ADORA1, involved in myocardial ischemia, was significantly up-regulated in EAT. Levels of the prostaglandin D2 synthase (PTGDS gene, recently associated with the progression of atherosclerosis, were significantly different in the three pairwise comparisons (EAT>MAT>SAT. The results of ADORA1 and PTGDS were confirmed by quantitative real-time PCR in 25 independent subjects. CONCLUSIONS: Overall, the transcriptional profiles of EAT and MAT were similar compared to the SAT. Despite this similarity, two genes involved in cardiovascular diseases, ADORA1 and PTGDS, were differentially up-regulated in EAT. These results provide insights about the biology of EAT and its potential implication in CAD.

  14. The Transcriptome of Human Epicardial, Mediastinal and Subcutaneous Adipose Tissues in Men with Coronary Artery Disease

    Science.gov (United States)

    Guauque-Olarte, Sandra; Gaudreault, Nathalie; Piché, Marie-Ève; Fournier, Dominique; Mauriège, Pascale; Mathieu, Patrick; Bossé, Yohan

    2011-01-01

    Background The biological functions of epicardial adipose tissue (EAT) remain largely unknown. However, the proximity of EAT to the coronary arteries suggests a role in the pathogenesis of coronary artery disease (CAD). The objectives of this study were to identify genes differentially regulated among three adipose tissues, namely EAT, mediastinal (MAT) and subcutaneous (SAT) and to study their possible relationships with the development of cardiovascular diseases. Methods and Results Samples were collected from subjects undergoing coronary artery bypass grafting surgeries. Gene expression was evaluated in the three adipose depots of six men using the Illumina® HumanWG-6 v3.0 expression BeadChips. Twenty-three and 73 genes were differentially up-regulated in EAT compared to MAT and SAT, respectively. Ninety-four genes were down-regulated in EAT compared to SAT. However, none were significantly down-regulated in EAT compared to MAT. More specifically, the expression of the adenosine A1 receptor (ADORA1), involved in myocardial ischemia, was significantly up-regulated in EAT. Levels of the prostaglandin D2 synthase (PTGDS) gene, recently associated with the progression of atherosclerosis, were significantly different in the three pairwise comparisons (EAT>MAT>SAT). The results of ADORA1 and PTGDS were confirmed by quantitative real-time PCR in 25 independent subjects. Conclusions Overall, the transcriptional profiles of EAT and MAT were similar compared to the SAT. Despite this similarity, two genes involved in cardiovascular diseases, ADORA1 and PTGDS, were differentially up-regulated in EAT. These results provide insights about the biology of EAT and its potential implication in CAD. PMID:21603615

  15. Lymphocyte trafficking and HIV infection of human lymphoid tissue in a rotating wall vessel bioreactor

    Science.gov (United States)

    Margolis, L. B.; Fitzgerald, W.; Glushakova, S.; Hatfill, S.; Amichay, N.; Baibakov, B.; Zimmerberg, J.

    1997-01-01

    The pathogenesis of HIV infection involves a complex interplay between both the infected and noninfected cells of human lymphoid tissue, the release of free viral particles, the de novo infection of cells, and the recirculatory trafficking of peripheral blood lymphocytes. To develop an in vitro model for studying these various aspects of HIV pathogenesis we have utilized blocks of surgically excised human tonsils and a rotating wall vessel (RWV) cell culture system. Here we show that (1) fragments of the surgically excised human lymphoid tissue remain viable and retain their gross cytoarchitecture for at least 3 weeks when cultured in the RWV system; (2) such lymphoid tissue gradually shows a loss of both T and B cells to the surrounding growth medium; however, this cellular migration is reversible as demonstrated by repopulation of the tissue by labeled cells from the growth medium; (3) this cellular migration may be partially or completely inhibited by embedding the blocks of lymphoid tissue in either a collagen or agarose gel matrix; these embedded tissue blocks retain most of the basic elements of a normal lymphoid cytoarchitecture; and (4) both embedded and nonembedded RWV-cultured blocks of human lymphoid tissue are capable of productive infection by HIV-1 of at least three various strains of different tropism and phenotype, as shown by an increase in both p24 antigen levels and free virus in the culture medium, and by the demonstration of HIV-1 RNA-positive cells inside the tissue identified by in situ hybridization. It is therefore reasonable to suggest that gel-embedded and nonembedded blocks of human lymphoid tissue, cocultured with a suspension of tonsillar lymphocytes in an RWV culture system, constitute a useful model for simulating normal lymphocyte recirculatory traffic and provide a new tool for testing the various aspects of HIV pathogenesis.

  16. Human Coronary Artery Smooth Muscle Cell Responses to Bioactive Polyelectrolyte Multilayer Interfaces

    Directory of Open Access Journals (Sweden)

    Robert G. Newcomer

    2011-01-01

    Full Text Available Under normal physiological conditions, mature human coronary artery smooth muscle cells (hCASMCs exhibit a “contractile” phenotype marked by low rates of proliferation and protein synthesis, but these cells possess the remarkable ability to dedifferentiate into a “synthetic” phenotype when stimulated by conditions of pathologic stress. A variety of polyelectrolyte multilayer (PEMU films are shown here to exhibit bioactive properties that induce distinct responses from cultured hCASMCs. Surfaces terminated with Nafion or poly(styrenesulfonic acid (PSS induce changes in the expression and organization of intracellular proteins, while a hydrophilic, zwitterionic copolymer of acrylic acid and 3-[2-(acrylamido-ethyl dimethylammonio] propane sulfonate (PAA-co-PAEDAPS is resistant to cell attachment and suppresses the formation of key cytoskeletal components. Differential expression of heat shock protein 90 and actin is observed, in terms of both their magnitude and cellular localization, and distinct cytoplasmic patterns of vimentin are seen. The ionophore A23187 induces contraction in confluent hCASMC cultures on Nafion-terminated surfaces. These results demonstrate that PEMU coatings exert direct effects on the cytoskeletal organization of attaching hCASMCs, impeding growth in some cases, inducing changes consistent with phenotypic modulation in others, and suggesting potential utility for PEMU surfaces as a coating for coronary artery stents and other implantable medical devices.

  17. Puerarin induces mitochondria-dependent apoptosis in hypoxic human pulmonary arterial smooth muscle cells.

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    Chan Chen

    Full Text Available BACKGROUND: Pulmonary vascular medial hypertrophy in hypoxic pulmonary arterial hypertension (PAH is caused in part by decreased apoptosis in pulmonary artery smooth muscle cells (PASMCs. Puerarin, an isoflavone purified from the Chinese medicinal herb kudzu, ameliorates chronic hypoxic PAH in animal models. Here we investigated the effects of puerarin on apoptosis of hypoxic human PASMCs (HPASMCs, and to determine the possible underlying mechanisms. METHODOLOGY/PRINCIPAL FINDINGS: HPASMCs were cultured for 24 h in normoxia or hypoxia (5% O₂ conditions with and without puerarin. Cell number and viability were determined with a hemacytometer or a cell counting kit. Apoptosis was detected with a TUNEL test, rhodamine-123 (R-123 fluorescence, a colorimetric assay, western blots, immunohistochemical staining and RT-PCR. Hypoxia inhibited mitochondria-dependent apoptosis and promoted HPASMC growth. In contrast, after puerarin (50 µM or more intervention, cell growth was inhibited and apoptosis was observed. Puerarin-induced apoptosis in hypoxic HPASMCs was accompanied by reduced mitochondrial membrane potential, cytochrome c release from the mitochondria, caspase-9 activation, and Bcl-2 down-regulation with concurrent Bax up-regulation. CONCLUSIONS/SIGNIFICANCE: Puerarin promoted apoptosis in hypoxic HPASMCs by acting on the mitochondria-dependent pathway. These results suggest a new mechanism of puerarin relevant to the management of clinical hypoxic pulmonary hypertension.

  18. Puerarin Induces Mitochondria-Dependent Apoptosis in Hypoxic Human Pulmonary Arterial Smooth Muscle Cells

    Science.gov (United States)

    Chen, Chan; Chen, Chun; Wang, Zhiyi; Wang, Liangxing; Yang, Lehe; Ding, Minjiao; Ding, Cheng; Sun, Yu; Lin, Quan; Huang, Xiaoying; Du, Xiaohong; Zhao, Xiaowei; Wang, Chuangyi

    2012-01-01

    Background Pulmonary vascular medial hypertrophy in hypoxic pulmonary arterial hypertension (PAH) is caused in part by decreased apoptosis in pulmonary artery smooth muscle cells (PASMCs). Puerarin, an isoflavone purified from the Chinese medicinal herb kudzu, ameliorates chronic hypoxic PAH in animal models. Here we investigated the effects of puerarin on apoptosis of hypoxic human PASMCs (HPASMCs), and to determine the possible underlying mechanisms. Methodology/Principal Findings HPASMCs were cultured for 24 h in normoxia or hypoxia (5% O2) conditions with and without puerarin. Cell number and viability were determined with a hemacytometer or a cell counting kit. Apoptosis was detected with a TUNEL test, rhodamine-123 (R-123) fluorescence, a colorimetric assay, western blots, immunohistochemical staining and RT-PCR. Hypoxia inhibited mitochondria-dependent apoptosis and promoted HPASMC growth. In contrast, after puerarin (50 µM or more) intervention, cell growth was inhibited and apoptosis was observed. Puerarin-induced apoptosis in hypoxic HPASMCs was accompanied by reduced mitochondrial membrane potential, cytochrome c release from the mitochondria, caspase-9 activation, and Bcl-2 down-regulation with concurrent Bax up-regulation. Conclusions/Significance Puerarin promoted apoptosis in hypoxic HPASMCs by acting on the mitochondria-dependent pathway. These results suggest a new mechanism of puerarin relevant to the management of clinical hypoxic pulmonary hypertension. PMID:22457823

  19. Adaptable setups for magnetic drug targeting in human muscular arteries: Design and implementation

    Science.gov (United States)

    Hajiaghajani, Amirhossein; Hashemi, Soheil; Abdolali, Ali

    2017-09-01

    Magnetic drug targeting has been used to steer magnetic therapeutic agents and has received much attention for capillaries and human brain arteries. In this paper, we focus on noninvasive targeting of nanoparticles in muscular arteries, in where the vessel diameter and blood flow are much challengingly higher than brain capillaries. We aim to design a low intensity magnetic field which avoids potential side effects on blood cells while steers particles with high targeting rate. The setup design procedure is considerably flexible to be used in a wide variety of large vessels. Using particle tracing, a new method is proposed to connect the geometry of the vessel under the action of targeting to the required magnetic force. Specifications of the coil which is placed outside the body are derived based on this required force. Mutual effects of coil dimensions on the produced magnetic force are elaborated and summarized in a design flowchart to be used for arbitrary muscular vessel sizes. The performance of the optimized coil is validated by in vitro experiments and it is shown that particles are steered with the average efficiency of 80.2% for various conditions.

  20. Biodegradable Polymers Influence the Effect of Atorvastatin on Human Coronary Artery Cells.

    Science.gov (United States)

    Strohbach, Anne; Begunk, Robert; Petersen, Svea; Felix, Stephan B; Sternberg, Katrin; Busch, Raila

    2016-01-22

    Drug-eluting stents (DES) have reduced in-stent-restenosis drastically. Yet, the stent surface material directly interacts with cascades of biological processes leading to an activation of cellular defense mechanisms. To prevent adverse clinical implications, to date almost every patient with a coronary artery disease is treated with statins. Besides their clinical benefit, statins exert a number of pleiotropic effects on endothelial cells (ECs). Since maintenance of EC function and reduction of uncontrolled smooth muscle cell (SMC) proliferation represents a challenge for new generation DES, we investigated the effect of atorvastatin (ATOR) on human coronary artery cells grown on biodegradable polymers. Our results show a cell type-dependent effect of ATOR on ECs and SMCs. We observed polymer-dependent changes in IC50 values and an altered ATOR-uptake leading to an attenuation of statin-mediated effects on SMC growth. We conclude that the selected biodegradable polymers negatively influence the anti-proliferative effect of ATOR on SMCs. Hence, the process of developing new polymers for DES coating should involve the characterization of material-related changes in mechanisms of drug actions.

  1. Biodegradable Polymers Influence the Effect of Atorvastatin on Human Coronary Artery Cells

    Directory of Open Access Journals (Sweden)

    Anne Strohbach

    2016-01-01

    Full Text Available Drug-eluting stents (DES have reduced in-stent-restenosis drastically. Yet, the stent surface material directly interacts with cascades of biological processes leading to an activation of cellular defense mechanisms. To prevent adverse clinical implications, to date almost every patient with a coronary artery disease is treated with statins. Besides their clinical benefit, statins exert a number of pleiotropic effects on endothelial cells (ECs. Since maintenance of EC function and reduction of uncontrolled smooth muscle cell (SMC proliferation represents a challenge for new generation DES, we investigated the effect of atorvastatin (ATOR on human coronary artery cells grown on biodegradable polymers. Our results show a cell type-dependent effect of ATOR on ECs and SMCs. We observed polymer-dependent changes in IC50 values and an altered ATOR-uptake leading to an attenuation of statin-mediated effects on SMC growth. We conclude that the selected biodegradable polymers negatively influence the anti-proliferative effect of ATOR on SMCs. Hence, the process of developing new polymers for DES coating should involve the characterization of material-related changes in mechanisms of drug actions.

  2. AN ANATOMICAL STUDY OF CORONARY ARTERY DOMINANCE IN HUMAN CADAVERIC HEARTS

    Directory of Open Access Journals (Sweden)

    Natasha

    2015-07-01

    Full Text Available CONTEXT: With ever increasing incidence of coronary heart disease, a thorough study of the coronary arteries is the need of time. AIM: The aim of the present study is to evaluate the coronary dominance pattern which will help the cardiac physicians and surgeons for better diagnosis and management of coronary arte ry disease. MATERIALS AND METHODS: The study undertaken in the Department of Anatomy, Assam Medical College included 75 perinatal and 15 adult cadaveric human hearts which were preserved in 10% formaldehyde solution after simple dissecting procedure and the dominance was noted. RESULTS: In the present study, out of total of 90 cases the right coronary dominance was found to be present in 58 cases (64.44%.This included 34(60.71% males and 24(70.59% females. Total cases of left coronary dominance were fo und to be 22(24.45%. Among these, 15(26.79% were males and 7(20.59% were females. Finally 10(11.11% co - dominant cases were found, of which 7 cases (12.50% were males and 3 cases (8.82% were females. CONCLUSION : Thus the study revealed that most of th e cases were having right coronary predominance. KEYWORDS : Coronary arteries, Dominance .

  3. Mass transport of low density lipoprotein in reconstructed hemodynamic environments of human carotid arteries: the role of volume and solute flux through the endothelium.

    Science.gov (United States)

    Kim, Sungho; Giddens, Don P

    2015-04-01

    The accumulation of low density lipoprotein (LDL) in the arterial intima is a critical step in the initiation and progression of atheromatous lesions. In this study we examine subject-specific LDL transport into the intima of carotid bifurcations in three human subjects using a three-pore model for LDL mass transfer. Subject-specific carotid artery computational models were derived using magnetic resonance imaging (MRI) to obtain the geometry and phase-contract MRI (PC-MRI) to acquire pulsatile inflow and outflow boundary conditions for each subject. The subjects were selected to represent a wide range of anatomical configurations and different stages of atherosclerotic development from mild to moderate intimal thickening. A fluid-solid interaction (FSI) model was implemented in the computational fluid dynamics (CFD) approach in order to consider the effects of a compliant vessel on wall shear stress (WSS). The WSS-dependent response of the endothelium to LDL mass transfer was modeled by multiple pathways to include the contributions of leaky junctions, normal junctions, and transcytosis to LDL solute and plasma volume flux from the lumen into the intima. Time averaged WSS (TAWSS) over the cardiac cycle was computed to represent the spatial WSS distribution, and wall thickness (WTH) was determined from black blood MRI (BBMRI) so as to visualize intimal thickening patterns in the bifurcations. The regions which are exposed to low TAWSS correspond to elevated WTH and higher mass and volume flux via the leaky junctions. In all subjects, the maximum LDL solute flux was observed to be immediately downstream of the stenosis, supporting observations that existing atherosclerotic lesions tend to progress in the downstream direction of the stenosis.

  4. Evidence for shear stress-mediated dilation of the internal carotid artery in humans

    DEFF Research Database (Denmark)

    Carter, Howard Henry; Atkinson, Ceri L; Heinonen, Ilkka H A

    2016-01-01

    Increases in arterial carbon dioxide tension (hypercapnia) elicit potent vasodilation of cerebral arterioles. Recent studies have also reported vasodilation of the internal carotid artery during hypercapnia, but the mechanism(s) mediating this extracranial vasoreactivity are unknown. Hypercapnia ...

  5. Interstitial and arterial-venous [K+] in human calf muscle during dynamic exercise

    DEFF Research Database (Denmark)

    Green, S; Langberg, Henning; Skovgaard, D

    2000-01-01

    little information on the response of [K+]I to exercise in human skeletal muscle. Five young healthy subjects performed plantar flexion exercise for four 5 min periods at increasing power outputs ( approximately 1-6 W) with 10 min intervening recovery periods, as well as for two 5 min periods......Changes in the concentration of interstitial K+ surrounding skeletal muscle fibres ([K+]I) probably play some role in the regulation of cardiovascular adjustments to muscular activity, as well as in the aetiology of muscle pain and fatigue during high-intensity exercise. However, there is very...... with ischaemia at approximately 1 and approximately 3 W. Microdialysis probes were inserted into the gastrocnemius medialis muscle of the right leg to measure [K+]I, and K+ release from the plantar flexors during and after incremental exercise was calculated from plasma flow and arterial-venous differences for K...

  6. STAT6 mediates apoptosis of human coronary arterial endothelial cells by interleukin-13.

    Science.gov (United States)

    Nishimura, Yuki; Nitto, Takeaki; Inoue, Teruo; Node, Koichi

    2008-03-01

    Interleukin (IL)-13 is a cytokine produced by type 2 helper T cells that has pathophysiological roles in allergic inflammation and fibrosis formation. IL-13 shares many functional properties with IL-4, which promotes apoptosis of endothelial cells (ECs). We here investigated the effects of IL-13 on apoptosis using human coronary artery endothelial cells (HCAECs). Assessment by WST-1 assay demonstrated that IL-13 as well as IL-4 significantly inhibited cell growth. IL-13 significantly attenuated the cell viability and induced apoptosis of HCAECs as well. Expression of mRNA for vascular endothelial cell growth factor, which maintains survival of ECs, was significantly diminished by IL-13. The effects of IL-13 and IL-4 were abolished by depletion of STAT6 using RNA interference. These results suggest that IL-13 attenuates EC viability by inducing apoptosis, and that STAT6 plays pivotal roles on IL-13- and IL-4-induced apoptosis in ECs.

  7. Multi wall carbon nanotubes induce oxidative stress and cytotoxicity in human embryonic kidney (HEK293) cells.

    Science.gov (United States)

    Reddy, Anreddy Rama Narsimha; Reddy, Yellu Narsimha; Krishna, Devarakonda Rama; Himabindu, Vurimindi

    2010-06-04

    The present study was aimed at evaluating the potential toxicity and the general mechanism involved in multi wall carbon nanotubes (MWCNT)-induced cytotoxicity using human embryonic kidney cell line (HEK293) cells. Two multi wall carbon nanotubes (coded as MWCNT1, size: 90-150nm and MWCNT2, size: 60-80nm) used in this study are MWCNT1 (produced by the electric arc method and size of the nanotubes was 90-150nm) and MWCNT2 (produced by the chemical vapor deposition method with size of 60-80nm). To elucidate the possible mechanisms of MWCNT induced cytotoxicity, cell viability, mitochondrial function (MTT assay), cell membrane damage (LDH assay), reduced glutathione (GSH), interleukin-8 (IL-8) and lipid peroxidation levels were quantitatively assessed under carbon nanotubes exposed (48h) conditions. Exposure of different sizes of two carbon nanotubes at dosage levels between 3 and 300mug/ml decreased cell viability in a concentration dependent manner. The IC(50) values (concentration of nanoparticles to induce 50% cell mortality) of two (MWCNT1, MWCNT2) nanoparticles were found as 42.10 and 36.95mug/ml. Exposure of MWCNT (10-100mug/ml) to HEK cells resulted in concentration dependent cell membrane damage (as indicated by the increased levels of LDH), increased production of IL-8, increased TBARS and decreased intracellular glutathione levels. The cytotoxicity and oxidative stress was significantly more in MWCNT2 exposed cells than MWCNT1. In summary, exposure of carbon nanotubes resulted in a concentration dependent cytotoxicity in cultured HEK293 cells that was associated with increased oxidative stress.

  8. Perturbation of human coronary artery endothelial cell redox state and NADPH generation by methylglyoxal.

    Directory of Open Access Journals (Sweden)

    Philip E Morgan

    Full Text Available Diabetes is associated with elevated plasma glucose, increased reactive aldehyde formation, oxidative damage, and glycation/glycoxidation of biomolecules. Cellular detoxification of, or protection against, such modifications commonly requires NADPH-dependent reducing equivalents (e.g. GSH. We hypothesised that reactive aldehydes may modulate cellular redox status via the inhibition of NADPH-generating enzymes, resulting in decreased thiol and NADPH levels. Primary human coronary artery endothelial cells (HCAEC were incubated with high glucose (25 mM, 24 h, 37°C, or methylglyoxal (MGO, glyoxal, or glycolaldehyde (100-500 µM, 1 h, 37°C, before quantification of intracellular thiols and NADPH-generating enzyme activities. Exposure to MGO, but not the other species examined, significantly (P<0.05 decreased total thiols (∼35%, further experiments with MGO showed significant losses of GSH (∼40% and NADPH (∼10%; these changes did not result in an immediate loss of cell viability. Significantly decreased (∼10% NADPH-producing enzyme activity was observed for HCAEC when glucose-6-phosphate or 2-deoxyglucose-6-phosphate were used as substrates. Cell lysate experiments showed significant MGO-dose dependent inhibition of glucose-6-phosphate-dependent enzymes and isocitrate dehydrogenase, but not malic enzyme. Analysis of intact cell or lysate proteins showed that arginine-derived hydroimidazolones were the predominant advanced glycation end-product (AGE formed; lower levels of N(ε-(carboxyethyllysine (CEL and N(ε-(carboxymethyllysine (CML were also detected. These data support a novel mechanism by which MGO exposure results in changes in redox status in human coronary artery endothelial cells, via inhibition of NADPH-generating enzymes, with resultant changes in reduced protein thiol and GSH levels. These changes may contribute to the endothelial cell dysfunction observed in diabetes-associated atherosclerosis.

  9. Analysis of carotid artery plaque and wall boundaries on CT images by using a semi-automatic method based on level set model

    Energy Technology Data Exchange (ETDEWEB)

    Saba, Luca; Sannia, Stefano; Ledda, Giuseppe [University of Cagliari - Azienda Ospedaliero Universitaria di Cagliari, Department of Radiology, Monserrato, Cagliari (Italy); Gao, Hao [University of Strathclyde, Signal Processing Centre for Excellence in Signal and Image Processing, Department of Electronic and Electrical Engineering, Glasgow (United Kingdom); Acharya, U.R. [Ngee Ann Polytechnic University, Department of Electronics and Computer Engineering, Clementi (Singapore); Suri, Jasjit S. [Biomedical Technologies Inc., Denver, CO (United States); Idaho State University (Aff.), Pocatello, ID (United States)

    2012-11-15

    The purpose of this study was to evaluate the potentialities of a semi-automated technique in the detection and measurement of the carotid artery plaque. Twenty-two consecutive patients (18 males, 4 females; mean age 62 years) examined with MDCTA from January 2011 to March 2011 were included in this retrospective study. Carotid arteries are examined with a 16-multi-detector-row CT system, and for each patient, the most diseased carotid was selected. In the first phase, the carotid plaque was identified and one experienced radiologist manually traced the inner and outer boundaries by using polyline and radial distance method (PDM and RDM, respectively). In the second phase, the carotid inner and outer boundaries were traced with an automated algorithm: level-set-method (LSM). Data were compared by using Pearson rho correlation, Bland-Altman, and regression. A total of 715 slices were analyzed. The mean thickness of the plaque using the reference PDM was 1.86 mm whereas using the LSM-PDM was 1.96 mm; using the reference RDM was 2.06 mm whereas using the LSM-RDM was 2.03 mm. The correlation values between the references, the LSM, the PDM and the RDM were 0.8428, 0.9921, 0.745 and 0.6425. Bland-Altman demonstrated a very good agreement in particular with the RDM method. Results of our study indicate that LSM method can automatically measure the thickness of the plaque and that the best results are obtained with the RDM. Our results suggest that advanced computer-based algorithms can identify and trace the plaque boundaries like an experienced human reader. (orig.)

  10. Earliest effects of sudden occlusions on pressure profiles in selected locations of the human systemic arterial system

    Science.gov (United States)

    Majka, Marcin; Gadda, Giacomo; Taibi, Angelo; Gałązka, Mirosław; Zieliński, Piotr

    2017-03-01

    We have developed a numerical simulation method for predicting the time dependence (wave form) of pressure at any location in the systemic arterial system in humans. The method uses the matlab-Simulink environment. The input data include explicitly the geometry of the arterial tree, treated up to an arbitrary bifurcation level, and the elastic properties of arteries as well as rheological parameters of blood. Thus, the impact of anatomic details of an individual subject can be studied. The method is applied here to reveal the earliest stages of mechanical reaction of the pressure profiles to sudden local blockages (thromboses or embolisms) of selected arteries. The results obtained with a purely passive model provide reference data indispensable for studies of longer-term effects due to neural and humoral mechanisms. The reliability of the results has been checked by comparison of two available sets of anatomic, elastic, and rheological data involving (i) 55 and (ii) 138 arterial segments. The remaining arteries have been replaced with the appropriate resistive elements. Both models are efficient in predicting an overall shift of pressure, whereas the accuracy of the 55-segment model in reproducing the detailed wave forms and stabilization times turns out dependent on the location of the blockage and the observation point.

  11. Nature and origin of the neointima in whole vessel wall organ culture of the human saphenous vein

    NARCIS (Netherlands)

    Slomp, J.; Gittenberger - Groot, A.C. de; Munsteren, J.C. van; Huysmans, H.A.; Bockel, J.H. van; Hinsbergh, V.W.M. van; Poelmann, R.E.

    1996-01-01

    Intimal proliferation is a characteristic feature of arteriosclerosis. Whole vessel wall organ culture systems have been developed to study the early stages of neointima formation. We have cultured a large number of explants of human saphenous vein specimens for several weeks, and have identified th

  12. Cell wall trapping of autocrine peptides for human G-protein-coupled receptors on the yeast cell surface.

    Directory of Open Access Journals (Sweden)

    Jun Ishii

    Full Text Available G-protein-coupled receptors (GPCRs regulate a wide variety of physiological processes and are important pharmaceutical targets for drug discovery. Here, we describe a unique concept based on yeast cell-surface display technology to selectively track eligible peptides with agonistic activity for human GPCRs (Cell Wall Trapping of Autocrine Peptides (CWTrAP strategy. In our strategy, individual recombinant yeast cells are able to report autocrine-positive activity for human GPCRs by expressing a candidate peptide fused to an anchoring motif. Following expression and activation, yeast cells trap autocrine peptides onto their cell walls. Because captured peptides are incapable of diffusion, they have no impact on surrounding yeast cells that express the target human GPCR and non-signaling peptides. Therefore, individual yeast cells can assemble the autonomous signaling complex and allow single-cell screening of a yeast population. Our strategy may be applied to identify eligible peptides with agonistic activity for target human GPCRs.

  13. Predicting pulmonary fibrosis in humans after exposure to multi-walled carbon nanotubes (MWCNTs).

    Science.gov (United States)

    Sharma, Monita; Nikota, Jake; Halappanavar, Sabina; Castranova, Vincent; Rothen-Rutishauser, Barbara; Clippinger, Amy J

    2016-07-01

    The increased production and use of multi-walled carbon nanotubes (MWCNTs) in a diverse array of consumer, medical, and industrial applications have raised concerns about potential human exposure to these materials in the workplace and ambient environments. Inhalation is a primary route of exposure to MWCNTs, and the existing data indicate that they are potentially hazardous to human health. While a 90-day rodent inhalation test (e.g., OECD Test No. 413: subchronic inhalation toxicity: 90-day study or EPA Health Effects Test Guidelines OPPTS 870.3465 90-day inhalation toxicity) is recommended by the U.S. Environmental Protection Agency Office of Pollution Prevention and Toxics for MWCNTs (and other CNTs) if they are to be commercially produced (Godwin et al. in ACS Nano 9:3409-3417, 2015), this test is time and cost-intensive and subject to scientific and ethical concerns. As a result, there has been much interest in transitioning away from studies on animals and moving toward human-based in vitro and in silico models. However, given the multiple mechanisms of toxicity associated with subchronic exposure to inhaled MWCNTs, a battery of non-animal tests will likely be needed to evaluate the key endpoints assessed by the 90-day rodent study. Pulmonary fibrosis is an important adverse outcome related to inhalation exposure to MWCNTs and one that the non-animal approach should be able to assess. This review summarizes the state-of-the-science regarding in vivo and in vitro toxicological methods for predicting MWCNT-induced pulmonary fibrosis.

  14. Proteomic analysis of the effect of iptakalim on human pulmonary arterial smooth muscle cell proliferation

    Institute of Scientific and Technical Information of China (English)

    Mingxia YANG; Zhengxia LIU; Shu ZHANG; Yu JING; Shijiang ZHANG; Weiping XIE; Lei MA; Changliang ZHU; Hong WANG

    2009-01-01

    Aim:To investigate the anti-proliferative effect of iptakalim (Ipt),a newly selective KATP channel opener,in endothelin-1 (ET-1)-induced human pulmonary arterial smooth muscle cells (PASMCs) using proteomic analysis.Methods: Human PASMCs were incubated with ET-1 (10-8 mol/L) and ETA (10-8 mol/L) plus iptaklim (10-5 mol/L) for 24 h.Analysis via 2-DE gel electrophoresis and MALDI-TOF-MS was employed to display the different protein profiles of whole-cell protein from cultures of control,ET-1 treatment alone,and treatment with ET-1 and iptaklim combined.Real time RT-PCR and Western blot analysis were used to confirm the proteomic analysis.Results: When iptakalim inhibited the proliferative effect of ET-1 in human PASMCs by opening the KATP channels,the expression of different groups of cellular proteins was changed,including cytoskeleton-associated proteins,plasma mem-brane proteins and receptors,chaperone proteins,ion transport-associated proteins,and glycolytic and metabolism-associ-ated proteins.We found that iptakalim could inhibit the proliferation of human PASMCs partly by affecting the expression of Hsp60,vimentin,nucleoporin P54 (NUP54) and Bcl-XL by opening the KATP channel.Conclusion: The data suggest that a wide range of signaling pathways may be involved in abolishing ET-1-induced prolif-eration of human PASMCs following iptakalim treatment.

  15. Patient-Specific Simulation of Coronary Artery Pressure Measurements: An In Vivo Three-Dimensional Validation Study in Humans

    Directory of Open Access Journals (Sweden)

    Panagiotis K. Siogkas

    2015-01-01

    Full Text Available Pressure measurements using finite element computations without the need of a wire could be valuable in clinical practice. Our aim was to compare the computed distal coronary pressure values with the measured values using a pressure wire, while testing the effect of different boundary conditions for the simulation. Eight coronary arteries (lumen and outer vessel wall from six patients were reconstructed in three-dimensional (3D space using intravascular ultrasound and biplane angiographic images. Pressure values at the distal and proximal end of the vessel and flow velocity values at the distal end were acquired with the use of a combo pressure-flow wire. The 3D lumen and wall models were discretized into finite elements; fluid structure interaction (FSI and rigid wall simulations were performed for one cardiac cycle both with pulsatile and steady flow in separate simulations. The results showed a high correlation between the measured and the computed coronary pressure values (coefficient of determination [r2] ranging between 0.8902 and 0.9961, while the less demanding simulations using steady flow and rigid walls resulted in very small relative error. Our study demonstrates that computational assessment of coronary pressure is feasible and seems to be accurate compared to the wire-based measurements.

  16. Dynamic Changes of Pulmonary Arterial Pressure and Ductus Arteriosus in Human Newborns From Birth to 72 Hours of Age

    OpenAIRE

    2016-01-01

    Abstract Normal pulmonary artery pressure and pulmonary hypertension assessment of newborns is rarely reported. The aim of the study is to explore dynamic changes of pulmonary arterial pressure and ductus arteriosus in human newborns from birth to 72 h of age with echocardiography. A total of 76 cases of normal newborns were prospectively detected by echocardiography after birth of 2 h, 6 h, 12 h, 24 h, 48 h, and 72 h, respectively. Ductus arteriosus diameter, blood shunt direction, blood flo...

  17. Commercial single-walled carbon nanotubes effects in fibrinolysis of human umbilical vein endothelial cells.

    Science.gov (United States)

    Rodríguez-Yáñez, Yury; Bahena-Uribe, Daniel; Chávez-Munguía, Bibiana; López-Marure, Rebeca; González-Monroy, Stuart; Cisneros, Bulmaro; Albores, Arnulfo

    2015-08-01

    Recent studies have demonstrated that carbon nanotubes (CNTs) induce platelet aggregation, endothelial dysfunction and vascular thrombosis. However, there is little information on the effects of CNTs on fibrinolysis. We investigated the role of pristine-commercial single-walled carbon nanotubes (SWCNTs) with <3% Co content in fibrinolysis and their contribution to the induction of pro-thrombotic processes in human vein endothelial cells (HUVEC). SWCNTs alone produced concentration-dependent oxidation, as measured by a dithiothreitol oxidation assay. Internalized SWCNTs were located in HUVEC treated with 25 μg/ml using transmission electron microscopy, whereas treatment with 50 μg/ml compromised cell viability, and oxidative stress increased significantly at 5 μg/ml. The study showed that in HUVEC treated with 25 μg SWCNT/ml, fibrinolysis-related gene expression and protein levels had increased by 3-12 h after treatment (serpine-1: 13-fold; PLAT: 11-fold and PLAU: 2-fold), but only the PAI-1 protein was increased (1.5-fold), whereas tissue and urokinase plasminogen activator proteins (tPA and uPA, respectively) tended to decrease. In summary, pristine SWCNTs treatment resulted in evident HUVEC damage caused by cell fiber contact, internalization, and oxidative stress due to contaminant metals. The generation of endothelial dysfunction, as shown by the altered expression of genes and proteins involved in fibrinolysis, suggest that SWCNTs display pro-thrombotic effects.

  18. [Morphofunctional correlation in congenital anomalies of the coronary arteries. I. Coronary artery fistulas].

    Science.gov (United States)

    Rangel-Abundis, A; Muñoz-Castellanos, L; Marín, G; Chávez Pérez, E; Badui, E

    1994-01-01

    In order to explain the congenital coronary arteries malformations, the authors review the recent concepts on the coronary artery morphogenesis, based in the findings that in the human embryo, these arteries evolve from three sources: 1) endothelial aortic buds, 2) cavitary cellular groups from pericardial origin and with angiogenic character, which migrate to the cardiac zones where the coronary arteries will be distributed, and 3) the intramyocardial sinusoids. The anatomic and histologic cardiac alterations will be reflected in modifications of the coronary artery pattern. The coronary artery fistulae are formed by the persistence of the sponge structure of the myocardial wall, present in the early ontogenic steps of the cardiac development; such fistulae alter the normal functions of the coronary vascular tree and are capable to cause angina pectoris to the patient through diverse mechanisms: absence of capillarization, steal phenomenon aggravated by the altered coronary arteries properties when aneurysm or vascular channels are developed. The authors suggest a classification of the congenital coronary arteries anomalies: I. Anomalous origin in the sinus of Valsalva (anomalous and ectopic origin), II. Malformations of the coronary branches (in number, distribution and wall anomalies) and III. Anomalous connection of the coronary arteries: fistulae and persistence of the intramyocardial sinusoids isolated or communicated to left and right ventricles. The latter are frequently associated with aortic or pulmonary valve atresia. They do not cause myocardial ischemia and are formed secondary to the intracavitary elevated pressure which maintained the persistence, dilatation and communication of the ventricular chambers with such sinusoids and coronary arteries in the case of pulmonary valve atresia and with coronary veins in the case of aortic valve atresia.

  19. Exposure of aconitase to smoking-related oxidants results in iron loss and increased iron response protein-1 activity: potential mechanisms for iron accumulation in human arterial cells

    DEFF Research Database (Denmark)

    Talib, Jihan; Davies, Michael Jonathan

    2016-01-01

    Smokers have an elevated risk of cardiovascular disease, but the origin(s) of this increased risk are incompletely defined. Evidence supports an accumulation of the oxidant-generating enzyme myeloperoxidase (MPO) in the inflamed artery wall, and smokers have high levels of SCN−, a preferred MPO...

  20. Arterial specification of endothelial cells derived from human induced pluripotent stem cells in a biomimetic flow bioreactor.

    Science.gov (United States)

    Sivarapatna, Amogh; Ghaedi, Mahboobe; Le, Andrew V; Mendez, Julio J; Qyang, Yibing; Niklason, Laura E

    2015-01-01

    Endothelial cells (ECs) exist in different microenvironments in vivo, including under different levels of shear stress in arteries versus veins. Standard stem cell differentiation protocols to derive ECs and EC-subtypes from human induced pluripotent stem cells (hiPSCs) generally use growth factors or other soluble factors in an effort to specify cell fate. In this study, a biomimetic flow bioreactor was used to subject hiPSC-derived ECs (hiPSC-ECs) to shear stress to determine the impacts on phenotype and upregulation of markers associated with an anti-thrombotic, anti-inflammatory, arterial-like phenotype. The in vitro bioreactor system was able to efficiently mature hiPSC-ECs into arterial-like cells in 24 h, as demonstrated by qRT-PCR for arterial markers EphrinB2, CXCR4, Conexin40 and Notch1, as well protein-level expression of Notch1 intracellular domain (NICD). Furthermore, the exogenous addition of soluble factors was not able to fully recapitulate this phenotype that was imparted by shear stress exposure. The induction of these phenotypic changes was biomechanically mediated in the shear stress bioreactor. This biomimetic flow bioreactor is an effective means for the differentiation of hiPSC-ECs toward an arterial-like phenotype, and is amenable to scale-up for culturing large quantities of cells for tissue engineering applications.

  1. Tyrosine Phosphorylation Modulates the Vascular Responses of Mesenteric Arteries from Human Colorectal Tumors

    Directory of Open Access Journals (Sweden)

    Eduardo Ferrero

    2013-01-01

    Full Text Available The aim of this study was to analyze whether tyrosine phosphorylation in tumoral arteries may modulate their vascular response. To do this, mesenteric arteries supplying blood flow to colorectal tumors or to normal intestine were obtained during surgery and prepared for isometric tension recording in an organ bath. Increasing tyrosine phosphorylation with the phosphatase inhibitor, sodium orthovanadate produced arterial contraction which was lower in tumoral than in control arteries, whereas it reduced the contraction to noradrenaline in tumoral but not in control arteries and reduced the relaxation to bradykinin in control but not in tumoral arteries. Protein expression of VEGF-A and of the VEGF receptor FLT1 was similar in control and tumoral arteries, but expression of the VEGF receptor KDR was increased in tumoral compared with control arteries. This suggests that tyrosine phosphorylation may produce inhibition of the contraction in tumoral mesenteric arteries, which may increase blood flow to the tumor when tyrosine phosphorylation is increased by stimulation of VEGF receptors.

  2. Physiological and pharmacological characterization of transmembrane acid extruders in cultured human umbilical artery smooth muscle cells

    Directory of Open Access Journals (Sweden)

    Gunng-Shinng Chen

    2015-01-01

    Full Text Available Background: Intracellular pH (pH i is a pivotal factor for cellular functions and homeostasis. Apart from passive intracellular buffering capacity, active transmembrane transporters responsible for kinetic changes of pH i impacts. Acid extrusion transporters such as Na + /H + exchanger (NHE and Na + /HCO3− cotransporter (NBC have been found to be activated when cells are in an acidic condition in different cell types. However, such far, the pH i regulators have not been characterized in human umbilical artery smooth muscle cells (HUASMCs. Materials and Methods: We, therefore, investigated the mechanism of pH i recovery from intracellular acidosis, induced by NH 4 Cl-prepulse, using pH-sensitive fluorescence dye: 2′,7′-bis(2-carboxethyl-5(6-carboxy-fluorescein in HUASMCs. Cultured HUASMCs were derived from the segments of the human umbilical artery that were obtained from women undergoing children delivery. Results: The resting pH i is 7.23 ± 0.03 when cells in HEPES (nominally HCO 3− -free buffered solution. The resting pH i is higher as 7.27 ± 0.03 when cells in CO 2 /HCO3− -buffered solution. In HEPES-buffered solution, a pH i recovery following induced intracellular acidosis could be inhibited completely by 30 μM HOE 694 (a specific NHE inhibitor or by removing [Na +]o . In 5% CO2/HCO3− -buffered solution, 30 μM HOE 694 slowed the pH i recovery from the induced intracellular acidosis only. On the contrary, HOE 694 adding together with 0.2 mM 4,4′-diisothiocyanatostilbene-2,2′-disulphonic acid (a specific NBC inhibitor or removal of [Na +]o entirely blocked the acid extrusion. By using Western blot technique, we demonstrated that four different isoforms of NBC, that is, SLC4A8 (NBCBE, SLC4A7 (NBCn1, SLC4A5 (NBCe2 and SLC4A4 (NBCe1, co-exist in the HUASMCs. Conclusions: We demonstrate, for the 1 st time, that apart from the housekeeping NHE1, another Na + couple HCO3− -transporter, that is, NBC, functionally coexists to

  3. Coexistence of at least three distinct beta-adrenoceptors in human internal mammary artery.

    Science.gov (United States)

    Shafiei, M; Omrani, G; Mahmoudian, M

    2000-01-01

    The internal mammary artery (IMA) is currently the preferred conduit for myocardial revascularization. However, perioperative vasospasm and a hypoperfusion state during maximal exercise may limit its use as a bypass graft. The mechanism of spasm has not been clearly defined. Since beta-adrenoceptor activation plays a major role in vasorelaxation, the present study was carried out to investigate the beta-adrenoceptor responsiveness of human IMA smooth muscle. Isoproterenol produced a concentration-dependent relaxation in endothelium-denuded IMA segments, precontracted with phenylephrine (maximal relaxation 46.33+/-5.45%). Atenolol (10(-6)M) and propranolol (2x10(-7)M) inhibited isoproterenol-induced relaxation. While atenolol produced partial inhibition, propranolol caused a complete inhibition in a majority of the segments and a partial inhibition in a minority. BRL 37344, a selective beta 3-adrenoceptor agonist, produced a concentration-dependent relaxation in phenylephrine-precontracted rings of endothelium-denuded IMA (maximal relaxation 40.35+/-4.07%). Cyanopindolol, a beta-adrenoceptor partial agonist, produced a marked relaxation (58.65+/-6.2%) in endothelium-denuded IMA rings, precontracted with phenylephrine. Cyanopindolol-induced relaxation was resistant to blockade by propranolol (2x10(-7)M). Spontaneous contractions of IMA rings were also observed in some cases that were inhibited by isoproterenol and BRL 37344. This observation implies the important role of beta-adrenoceptor activation in prevention of human IMA spasm. The results obtained in present study indicate that human IMA smooth muscle possesses an atypical beta-adrenoceptor together with beta1- and beta2-adrenoceptors. Regarding the relaxation induced in IMA rings by adding BRL 37344, the possible identical entities of IMA atypical beta-adrenoceptors and beta 3-adrenoceptors are suggested.

  4. Arterial baroreflex control of muscle sympathetic nerve activity under orthostatic stress in humans

    Directory of Open Access Journals (Sweden)

    Masashi eIchinose

    2012-08-01

    Full Text Available The mechanisms by which blood pressure is maintained against the orthostatic stress caused by gravity’s effect on the fluid distribution within the body are important issues in physiology, especially in humans who usually adopt an upright posture. Peripheral vasoconstriction and increased heart rate are major cardiovascular adjustments to orthostatic stress and comprise part of the reflex response elicited via the carotid sinus and aortic baroreceptors (arterial baroreflex: ABR and cardiopulmonary stretch receptors (cardiopulmonary baroreflex. In a series of studies, we have been characterizing the ABR-mediated regulation of cardiovascular hemodynamics and muscle sympathetic nerve activity (MSNA while applying orthostatic stress in humans. We have found that under orthostatic stress, dynamic carotid baroreflex responses are modulated as exemplified by the increases in the MSNA, blood pressure and heart rate responses elicited by carotid baroreflex unloading and the shorter period of MSNA suppression, comparable reduction and faster recovery of MAP and greater heart rate response to carotid baroreflex stimulation. Our results also show that ABR-mediated beat-to-beat control over burst incidence, burst strength and total MSNA is progressively modulated as orthostatic stress is increased until induction of syncope, and that the sensitivity of ABR control over the aforementioned MSNA variables is substantially reduced during the development of syncope. We suggest that in humans, the modulation of ABR function under orthostatic stress may be one of the mechanisms by which blood pressure is maintained and orthostatic hypotension limited, and impairment of ABR control over sympathetic vasomotor activity leads to the severe hypotension associated with orthostatic syncope.

  5. Correlation between arterial wall stiffness, N-terminal prohormone of brain natriuretic peptide, functional and structural myocardial abnormalities in patients with type 2 diabetes mellitus and cardiac autonomic neuropathy

    Directory of Open Access Journals (Sweden)

    Viktoriya Aleksandrovna Serhiyenko

    2013-12-01

    Full Text Available Aim. To assess arterial wall stiffness, plasma levels of of N-terminal prohormone of brain natriuretic peptide (NT-proBNP, as well as functional state and structure of the myocardium in patients with type 2 diabetes mellitus (T2DM and cardiac autonomic neuropathy (CAN.Materials and Methods. The study involved a total of 65 patients with T2DM. 12 had no evidence of cardiovascular disease (CVD or CAN, 14 were diagnosed with subclinical stage of CAN, 18 – with functional stage, and 21 – with organic stage. We measured aortic pulse wave velocity (PWV, aortic augmentation index (AIx, brachial artery AIx, ambulatory arterial stiffness index (AASI and plasma levels of NT-proBNP. Clinical examination included ECG, Holter monitoring, ambulatory BP measurement and echocardiography.Results. Patients with isolated T2DM showed a trend for increased vascular wall stiffness. PWV was increased in patients with subclinical stage of CAN. Aortic and brachial AIx, PWV and AASI were elevated in patients with functional stage of CAN, PWV being significantly higher vs. subclinical CAN subgroup. Organic stage was characterized by pathologically increased values of all primary parameters; PWV and AASI were significantly higher compared with other groups. Development and progression of CAN was accompanied by an increase in NT-proBNP plasma levels. Concentration of NT-proBNP was in direct correlation with left ventricular mass (LVM and PWV. PWV and LVM values also directly correlated between themselves.Conclusion. Development and progression of CAN in patients with T2DM is accompanied by an increase in vascular wall stiffness. The elevation of plasma NT-proBNP in patients with T2DM correlates with the development of CAN and is significantly and independently associated with an increase in LVM and PWV. Our data suggests the pathophysiological interconnection between metabolic, functional and structural myocardial abnormalities in patients with T2DM and CAN.

  6. An increase in the threshold of citric acid-induced cough during chest wall vibration in healthy humans.

    Science.gov (United States)

    Kondo, T; Kobayashi, I; Hayama, N; Ohta, Y

    1998-10-01

    This study tested the hypothesis that the afferent input from the respiratory muscles may be involved in the neural mechanisms inducing cough responses. Coughing was evoked in conscious healthy humans by the inhalation of citric acid aerosol of several concentrations either during or not during chest wall vibration (100 Hz) at the right second intercostal space or during vibration of the right thigh. The mean threshold citric acid concentration to induce coughing was significantly higher during chest wall vibration (geometric mean, 131.8 mg/ml) than without vibration (75.9 mg/ml). Vibration after topical anesthesia of the chest wall skin did not significantly change the threshold concentration of citric acid. The threshold citric acid concentration during vibration of the right thigh did not significantly differ from that without vibration. We concluded that inputs from the chest wall afferent, presumably from the intercostal muscle or costovertebral joint, may have an inhibitory effect on the initiation of coughing at the higher neural structure in conscious humans.

  7. The specific role of gravitational accelerations for arterial adaptations.

    Science.gov (United States)

    Weber, Tobias; Ducos, Michel; Mulder, Edwin; Herrera, Frankyn; Brüggemann, Gert-Peter; Bloch, Wilhelm; Rittweger, Jörn

    2013-02-01

    It is mostly agreed that arterial adaptations occur, among others, in response to changes in mechanical stimuli. Models like bed rest, spinal cord injury, or limb suspension have been applied to study vascular adaptations to unloading in humans. However, these models cannot distinguish the role of muscle contractions and the role of gravitational accelerations for arterial adaptation. The HEPHAISTOS orthosis allows normal ambulation, while it significantly reduces force generation in the lower leg muscles. Eleven subjects wore HEPHAISTOS unilaterally for 56 days and were followed up for another 4 wk. Arterial diameters, intima media thickness (IMT), flow-mediated dilation (FMD), and resting blood flow (BF(rest)) were measured using high-frequency ultrasonography. Arterial adaptations were investigated in the superficial femoral artery (SFA), the brachial artery (BA), and the carotid artery (CA). Mean SFA resting diameter was decreased from 6.57 mm (SD = 0.74 mm) at baseline to 5.77 mm (SD = 0.87 mm) at the end of the intervention (P muscular contractions for arterial diameter adaptations. Moreover, we propose that FMD and wall-to-lumen ratio are unaffected by ambulating with the HEPHAISTOS orthosis, which is suggestive of habitual acceleration profiles in the lower leg constituting an important stimulus for the maintenance of FMD and wall-to-lumen ratio.

  8. The impact of scaled boundary conditions on wall shear stress computations in atherosclerotic human coronary bifurcations.

    Science.gov (United States)

    Schrauwen, Jelle T C; Schwarz, Janina C V; Wentzel, Jolanda J; van der Steen, Antonius F W; Siebes, Maria; Gijsen, Frank J H

    2016-05-15

    The aim of this study was to determine if reliable patient-specific wall shear stress (WSS) can be computed when diameter-based scaling laws are used to impose the boundary conditions for computational fluid dynamics. This study focused on mildly diseased human coronary bifurcations since they are predilection sites for atherosclerosis. Eight patients scheduled for percutaneous coronary intervention were imaged with angiography. The velocity proximal and distal of a bifurcation was acquired with intravascular Doppler measurements. These measurements were used for inflow and outflow boundary conditions for the first set of WSS computations. For the second set of computations, absolute inflow and outflow ratios were derived from geometry-based scaling laws based on angiography data. Normalized WSS maps per segment were obtained by dividing the absolute WSS by the mean WSS value. Absolute and normalized WSS maps from the measured-approach and the scaled-approach were compared. A reasonable agreement was found between the measured and scaled inflows, with a median difference of 0.08 ml/s [-0.01; 0.20]. The measured and the scaled outflow ratios showed a good agreement: 1.5 percentage points [-19.0; 4.5]. Absolute WSS maps were sensitive to the inflow and outflow variations, and relatively large differences between the two approaches were observed. For normalized WSS maps, the results for the two approaches were equivalent. This study showed that normalized WSS can be obtained from angiography data alone by applying diameter-based scaling laws to define the boundary conditions. Caution should be taken when absolute WSS is assessed from computations using scaled boundary conditions.

  9. Gene expression profile of human lung epithelial cells chronically exposed to single-walled carbon nanotubes

    Science.gov (United States)

    Chen, Dongquan; Stueckle, Todd A.; Luanpitpong, Sudjit; Rojanasakul, Yon; Lu, Yongju; Wang, Liying

    2015-01-01

    A rapid increase in utility of engineered nanomaterials, including carbon nanotubes (CNTs), has raised a concern over their safety. Based on recent evidence from animal studies, pulmonary exposure of CNTs may lead to nanoparticle accumulation in the deep lung without effective clearance which could interact with local lung cells for a long period of time. Physicochemical similarities of CNTs to asbestos fibers may contribute to their asbestos-like carcinogenic potential after long-term exposure, which has not been well addressed. More studies are needed to identify and predict the carcinogenic potential and mechanisms for promoting their safe use. Our previous study reported a long-term in vitro exposure model for CNT carcinogenicity and showed that 6-month sub-chronic exposure of single-walled carbon nanotubes (SWCNT) causes malignant transformation of human lung epithelial cells. In addition, the transformed cells induced tumor formation in mice and exhibited an apoptosis resistant phenotype, a key characteristic of cancer cells. Although the potential role of p53 in the transformation process was identified, the underlying mechanisms of oncogenesis remain largely undefined. Here, we further examined the gene expression profile by using genome microarrays to profile molecular mechanisms of SWCNT oncogenesis. Based on differentially expressed genes, possible mechanisms of SWCNT-associated apoptosis resistance and oncogenesis were identified, which included activation of pAkt/p53/Bcl-2 signaling axis, increased gene expression of Ras family for cell cycle control, Dsh-mediated Notch 1, and downregulation of apoptotic genes BAX and Noxa. Activated immune responses were among the major changes of biological function. Our findings shed light on potential molecular mechanisms and signaling pathways involved in SWCNT oncogenic potential.

  10. Adrenomedullin is a potent inhibitor of angiotensin II-induced migration of human coronary artery smooth muscle cells.

    Science.gov (United States)

    Kohno, M; Yokokawa, K; Kano, H; Yasunari, K; Minami, M; Hanehira, T; Yoshikawa, J

    1997-06-01

    The migration of coronary artery medial smooth muscle cells (SMCs) into the intima is proposed to be an important process of intimal thickening in coronary atherosclerotic lesions. In the current study, we examined the possible interaction of adrenomedullin, a novel vasorelaxant peptide, and angiotensin II (Ang II) on human coronary artery SMC migration using Boyden's chamber method. Ang II stimulated SMC migration in a concentration-dependent manner between 10(6) and 10(8) mol/L. This stimulation was clearly blocked by the Ang II type 1 receptor antagonist losartan but not by the type 2 receptor antagonist PD 123319. The migration stimulatory effect of Ang II was chemotactic in nature for cultured human coronary artery SMCs but was not chemokinetic. Human adrenomedullin clearly inhibited Ang II-induced migration in a concentration-dependent manner. Human adrenomedullin stimulated cAMP formation in these cells. Inhibition by adrenomedullin of Ang II-induced SMC migration was paralleled by an increase in the cellular level of cAMP. 8-Bromo-cAMP, a cAMP analogue, and forskolin, an activator of adenylate cyclase, inhibited the Ang II-induced SMC migration. These results suggest that Ang II stimulates SMC migration via type 1 receptors in human coronary artery and adrenomedullin inhibits Ang II-induced migration at least partly through a cAMP-dependent mechanism. Taken together with the finding that adrenomedullin is synthesized in and secreted from vascular endothelial cells, this peptide may play a role as a local antimigration factor in certain pathological conditions.

  11. Repeated increases in blood flow, independent of exercise, enhance conduit artery vasodilator function in humans

    NARCIS (Netherlands)

    Naylor, L.H.; Carter, H.; Fitzsimons, M.G.; Cable, N.T.; Thijssen, D.H.J.; Green, D.J.

    2011-01-01

    This study aimed to determine the importance of repeated increases in blood flow to conduit artery adaptation, using an exercise-independent repeated episodic stimulus. Recent studies suggest that exercise training improves vasodilator function of conduit arteries via shear stress-mediated

  12. Effects of Dietary Decosahexaenoic Acid (Dha) on eNOS in Human Coronary Artery Endothelial Cells

    Science.gov (United States)

    Stebbins, Charles L.; Stice, James P.; Hart, C. Michael; Mbai, Fiona N.; Knowlton, Anne A.

    2015-01-01

    Endothelial dysfunction occurs in heart disease, and may reduce functional capacity via attenuations in peripheral blood flow. Dietary DHA may improve this dysfunction, but the mechanism is unknown. We determined if DHA enhances expression and activity of eNOS in cultured human coronary artery endothelial cells (HCAEC). HCAEC from 4 donors were treated with 5 nM, 50 nM, or 1 μM DHA for 7 days to model chronic DHA exposure. A trend for increased expression of eNOS and phospho-eNOS was observed with 5 and 50 nM DHA. DHA also enhanced expression of two proteins instrumental in activation of eNOS; phospho-Akt (5 and 50 nM) and HSP90 (50 nM and 1 μM). VEGF-induced activation of Akt increased NOx in treated (50 nM DHA) vs. untreated HCAEC (9.2±1.0 vs. 3.3±1.1 μmols/μg protein/μl). Findings suggest that DHA enhances eNOS and Akt activity, augments HSP90 expression, and increases NO bioavailability in response to Akt kinase activation PMID:18682551

  13. [Pulmonary arterial hypertension associated with human immunodeficiency virus infection: study of 4 cases].

    Science.gov (United States)

    Pousada, Guillermo; Baloira, Adolfo; Castro-Añón, Olalla; Valverde, Diana

    2016-04-15

    Pulmonary arterial hypertension (PAH) is a rare and progressive disease that can be inherited as autosomal dominant form. The BMPR2, ACVRL1 and ENG genes are main genes involved in the pathology. PAH associated to human immunodeficiency virus (HIV) is another rare disease with a low incidence, prevalence and survival. The main objective of this analysis was to study the clinical and molecular characteristics of PAH associated to HIV patients. We present 4 cases of HIV patients who developed PAH and have been treated with ambrisentan. Pathogenic mutations have been identify in analyzed genes in 3 of the four analyzed patients. In addition, these patients present other changes classified as benign after a thorough in silico analysis. We identified some changes in genetic modifiers that predispose to these patients to more severe phenotype. The clinical analysis can help to define monitoring for these patients and the administration of appropriate treatment. These patients also have shown several pathogenic mutations. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  14. Human brain: reliability and reproducibility of pulsed arterial spin-labeling perfusion MR imaging.

    Science.gov (United States)

    Jahng, Geon-Ho; Song, Enmin; Zhu, Xiao-Ping; Matson, Gerald B; Weiner, Michael W; Schuff, Norbert

    2005-03-01

    The Committee of Human Research of the University of California San Francisco approved this study, and all volunteers provided written informed consent. The goal of this study was to prospectively determine the global and regional reliability and reproducibility of noninvasive brain perfusion measurements obtained with different pulsed arterial spin-labeling (ASL) magnetic resonance (MR) imaging methods and to determine the extent to which within-subject variability and random noise limit reliability and reproducibility. Thirteen healthy volunteers were examined twice within 2 hours. The pulsed ASL methods compared in this study differ mainly with regard to magnetization transfer and eddy current effects. There were two main results: (a) Pulsed ASL MR imaging consistently had high measurement reliability (intraclass correlation coefficients greater than 0.75) and reproducibility (coefficients of variation less than 8.5%), and (b) random noise rather than within-subject variability limited reliability and reproducibility. It was concluded that low signal-to-noise ratios substantially limit the reliability and reproducibility of perfusion measurements.

  15. Colocalization of Serum Amyloid A with Microtubules in Human Coronary Artery Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Katja Lakota

    2011-01-01

    Full Text Available Serum amyloid A (SAA acts as a major acute phase protein and represents a sensitive and accurate marker of inflammation. Besides its hepatic origin, as the main source of serum SAA, this protein is also produced extrahepatically. The mRNA levels of SAA become significantly elevated following proinflammatory stimuli, as well as, are induced through their own positive feedback in human primary coronary artery endothelial cells. However, the intracellular functions of SAA are so far unknown. Colocalization of SAA with cytoskeletal filaments has previously been proposed, so we analyzed the colocalization of SAA with all three cytoskeletal elements: actin filaments, vimentin filaments, and microtubules. Immunofluorescent double-labeling analyses confirmed by PLA method revealed a strict colocalization of SAA with microtubules and a very infrequent attachment to vimentin while the distribution of actin filaments appeared clearly separated from SAA staining. Also, no significant colocalization was found between SAA and endomembranes labeled with the fluorescent lipid stain DiO6. However, SAA appears to be located also unbound in the cytosol, as well as inside the nucleus and within nanotubes extending from the cells or bridging neighboring cells. These different locations of SAA in endothelial cells strongly indicate multiple potential functions of this protein.

  16. Effect of Nateglinide and Glibenclamide on Endothelial Cells and Smooth Muscle Cells from Human Coronary Arteries

    Directory of Open Access Journals (Sweden)

    Seeger H

    2004-01-01

    Full Text Available In the present work the effect of nateglinide and glibenclamide, two different substances used for therapy of diabetes mellitus type 2, were investigated on the synthesis of markers of endothelial function and on the proliferation of smooth muscle cells in vitro. As cell models endothelial and smooth muscle cells from human coronary arteries were used. Both substances were tested at concentrations of 0.1, 1 and 10 mmol/l. As markers of endothelial function prostacyclin, endothelin and plasminogen-activator-inhibitor-1 (PAI-1 were tested. Nateglinide and glibenclamide were similarly able to inhibit endothelial endothelin and PAI-1 synthesis, but only at the highest concentration tested. Endothelial prostacyclin synthesis and proliferation of smooth muscle cells were not significantly changed by both substances. These results indicate that both nateglinide and glibenclamide may have potential in reducing negative long-term effects of diabetes such as atherogenesis. Kurzfassung: Effekt von Nateglinid und Glibenclamid auf Endothel- und Muskelzellen humaner Koronararterien. In der vorliegenden Arbeit wurde die Wirkung von Nateglinid und Glibenclamid, zweier unterschiedlicher Substanzen zur Behandlung des Diabetes mellitus Typ 2, auf die Synthese von Markern der Endothelfunktion und auf die Proliferation glatter Muskelzellen untersucht. Als Zellmodell dienten Endothelzellen und glatte Muskelzellen menschlicher Koronararterien. Beide Substanzen wurden in den Konzentrationen 0,1, 1 und 10 mmol/l getestet. Als Marker der Endothelfunktion dienten Prostazyklin, Endothelin und Plasminogen-Aktivator-Inhibitor-1 (PAI-1. Sowohl Nateglinid als auch Glibenclamid konnten die endotheliale Endothelin- und PAI-1-Produktion in ähnlichem Ausmaß senken, allerdings nur in der höchsten Konzentration. Die Prostazyklinsynthese und die Muskelzellproliferation wurden nicht signifikant beeinflußt. Diese Ergebnisse deuten daraufhin, daß sowohl Nateglinid als auch

  17. Arterial compliance measurement using a noninvasive laser Doppler measurement system

    Science.gov (United States)

    Hast, Jukka T.; Myllylae, Risto A.; Sorvoja, Hannu; Nissilae, Seppo M.

    2000-11-01

    The aim of this study was to study the elasticity of the arterial wall using a non-invasive laser Doppler measurement system. The elasticity of the arterial wall is described by its compliance factor, which can be determined when both blood pressure and the radial velocity of the arterial wall are known. To measure radical velocity we used a self- mixing interferometer. The compliance factors were measured from six healthy volunteers, whose ages were varied from 21 to 32. Although a single volunteer's compliance factor is presented as an example, this paper treated the volunteers as a group. First, the elastic modulus, which is inversely proportional to the compliance factor, was determined. Then, an exponential curve was fitted into the measured data and a characteristic equation for the elastic modulus of the arterial wall was determined. The elastic modulus was calculated at different pressures and the results were compared to the static incremental modulus of a dog's femoral artery. The results indicate that there is a correlation between human elastic and canine static incremental modulus for blood pressures varying from 60 to 110 mmHg.

  18. Effects of lipopolysaccharide infusion on arterial levels and transcerebral exchange kinetics of glutamate and glycine in healthy humans

    DEFF Research Database (Denmark)

    Berg, Ronan M G; Taudorf, Sarah; Bailey, Damian M

    2012-01-01

    . Cerebral blood flow (CBF) and arterial to jugular venous concentration differences of glutamate and glycine were determined before and after a 4-h intravenous infusion of Escherichia coli lipopolysaccharide (LPS, total dose of 0.3 ng/kg) in 12 healthy volunteers. The global cerebral net exchange......, their transcerebral exchange kinetics were unaffected. Inflammation-induced alterations of the circulating levels of glutamate and glycine, do not affect the global transcerebral exchange kinetics of these amino acids in healthy humans....

  19. PC02 Beta3-adrenoceptor agonist-induced relaxation of human placental arteries is reduced in pregnancy-induced hypertension

    Institute of Scientific and Technical Information of China (English)

    0BARTHEZ; CROUGET; PGUERARD; MJLEROYZAMIA; MBREUILLER-FOUCHE; EJMORCILLO; TCRPCO; PSAGOT; MDUMAS; MBARDOU

    2004-01-01

    AIM: Preeclampsia is one of the leading causes of neonatal and maternal morbidity and mortality. The purpose of this study is to investigate the functionality of β2- and 133-adrenoreceptors(β-ARs) in human placental arteries and to assess the influence of pregnancy-induced hypertension on β-ARs responsiveness.METHODS: We performed in vitro functional and biochemical studies as well as RT-PCR experiments. RESULTS: SR59119

  20. Sudden death in a captive meerkat (Suricata suricatta with arterial medial and myocardial calcification

    Directory of Open Access Journals (Sweden)

    Laura Bongiovann

    2016-04-01

    Full Text Available A 1-year-old male meerkat was found dead by the owner. The animal was clinically healthy and was regularly vaccinated for distemper virus. Necropsy revealed multifocal to confluent dry white areas in the myocardium, pneumonia and congestive hepatopathy. All the other organs, including gross vessels, were macroscopically normal. The heart showed histologically large, multifocal to confluent areas of mineralization of the myocardium and the wall of small coronary artery. Vascular calcifications were also observed in the hepatic portal tracts and kidneys arteries of small/medium sizes. The arterial lumen appeared narrowed and the wall thickened due to the calcification of the tunica media. In veterinary medicine, arterial mineralization is regarded as a metastatic calcification, as the result of hypercalcemia and/or hyperphosphatemia. However, today, the pathogenesis of medial artery calcification in humans seems to be the results of an active process resembling embryonic osteogenesis, rather than a mere passive process.

  1. Long-term use of first-line highly active antiretroviral therapy is not associated with carotid artery stiffness in human immunodeficiency virus-positive patients

    Directory of Open Access Journals (Sweden)

    Haohui Zhu

    2014-09-01

    Full Text Available Objective: To evaluate whether or not highly active antiretroviral therapy is associated with carotid artery stiffness in human immunodeficiency virus-positive patients in Henan Province, China. Method: Fifty human immunodeficiency virus-positive patients with at least a 5-year history of highly active antiretroviral therapy use and 50 human immunodeficiency virus-positive patients without a history of highly active antiretroviral therapy use were enrolled in this study. Carotid artery intima-media thickness and stiffness were determined by quantitative inter-media thickness and quantitative artery stiffness, respectively. Results: No statistically significant difference in carotid artery intima-media thickness and stiffness was observed between groups. A significant association between human immunodeficiency virus infection time and carotid artery stiffness was observed, but no significant association between human immunodeficiency virus infection time and intima-media thickness was found. No significant association between intima-media thickness, stiffness, and CD4+ and CD8+ T-cell counts were observed. Conclusion: The first-line highly active antiretroviral therapy currently used in China is not associated with carotid artery stiffness in human immunodeficiency virus-positive patients with good highly active antiretroviral therapy compliance. Human immunodeficiency virus may play a role in the development of atherosclerosis.

  2. Characterization of plaque components with intravascular ultrasound elastography in human femoral and coronary arteries in vitro

    NARCIS (Netherlands)

    C.L. de Korte (Chris); G. Pasterkamp (Gerard); H.A. Woutman; N. Bom (Klaas); A.F.W. van der Steen (Ton)

    2000-01-01

    textabstractBACKGROUND: The composition of plaque is a major determinant of coronary-related clinical syndromes. Intravascular ultrasound (IVUS) elastography has proven to be a technique capable of reflecting the mechanical properties of phantom material and the femoral arterial

  3. Fundamental relations between short-term RR interval and arterial pressure oscillations in humans

    Science.gov (United States)

    Taylor, J. A.; Eckberg, D. L.

    1996-01-01

    BACKGROUND: One of the principal explanations for respiratory sinus arrhythmia is that it reflects arterial baroreflex buffering of respiration-induced arterial pressure fluctuations. If this explanation is correct, then elimination of RR interval fluctuations should increase respiratory arterial pressure fluctuations. METHODS AND RESULTS: We measured RR interval and arterial pressure fluctuations during normal sinus rhythm and fixed-rate atrial pacing at 17.2+/-1.8 (SEM) beats per minute greater than the sinus rate in 16 healthy men and 4 healthy women, 20 to 34 years of age. Measurements were made during controlled-frequency breathing (15 breaths per minute or 0.25 Hz) with subjects in the supine and 40 degree head-up tilt positions. We characterized RR interval and arterial pressure variabilities in low-frequency (0.05 to 0.15 Hz) and respiratory-frequency (0.20 to 0.30 Hz) ranges with fast Fourier transform power spectra and used cross-spectral analysis to determine the phase relation between the two signals. As expected, cardiac pacing eliminated beat-to-beat RR interval variability. Against expectations, however, cardiac pacing in the supine position significantly reduced arterial pressure oscillations in the respiratory frequency (systolic, 6.8+/-1.8 to 2.9 +/-0.6 mm Hg2/Hz, P=.017). In contrast, cardiac pacing in the 40 degree tilt position increased arterial pressure variability (systolic, 8.0+/-1.8 to 10.8 +/-2.6, P=.027). Cross-spectral analysis showed that 40 degree tilt shifted the phase relation between systolic pressure and RR interval at the respiratory frequency from positive to negative (9 +/-7 degrees versus -17+/-11 degrees, P=.04); that is, in the supine position, RR interval changes appeared to lead arterial pressure changes, and in the upright position, RR interval changes appeared to follow arterial pressure changes. CONCLUSIONS: These results demonstrate that respiratory sinus arrhythmia can actually contribute to respiratory arterial

  4. Lifelong physical activity prevents an age-related reduction in arterial and skeletal muscle nitric oxide bioavailability in humans

    DEFF Research Database (Denmark)

    Nyberg, Michael Permin; Blackwell, James R; Damsgaard, Ramsus;

    2012-01-01

    Ageing has been proposed to be associated with increased levels of reactive oxygen species (ROS) that scavenge nitric oxide (NO). In eight young sedentary (23±1 years; Y), eight older lifelong sedentary (66±2 years; OS) and eight older lifelong physically active subjects (62±2 years; OA), we...... circulation and in the musculature of sedentary ageing humans due to increased oxidative stress. Lifelong physical activity opposes this effect within the trained musculature and in the arterial circulation. The lower blood flow response to leg exercise in ageing humans is not associated with a reduced...

  5. Influence of Carbon Monoxide on Growth and Apoptosis of Human Umbilical Artery Smooth Muscle Cells and Vein Endothelial Cells

    OpenAIRE

    2012-01-01

    Carbon monoxide (CO) is a vasoactive molecule that is generated by vascular cells as a byproduct of heme catabolism and it plays an important physiological role in circulation system. In order to investigate whether exogenous CO can mediate the growth and proliferation of vascular cells, in this study, we used 250 parts per million (ppm) of CO to treat human umbilical artery smooth muscle cell (hUASMC) and human umbilical vein endothelial cell (HuVEC) and further evaluated the growth and apop...

  6. Morphometric and hemodynamic analysis of atherosclerotic progression in human carotid artery bifurcations.

    Science.gov (United States)

    Huang, Xu; Yin, Xiaoping; Xu, Yingjin; Jia, Xinwei; Li, Jianhui; Niu, Pei; Shen, Wenzeng; Kassab, Ghassan S; Tan, Wenchang; Huo, Yunlong

    2016-03-01

    Although atherosclerosis has been widely investigated at carotid artery bifurcation, there is a lack of morphometric and hemodynamic data at different stages of the disease. The purpose of this study was to determine the lesion difference in patients with carotid artery disease compared with healthy control subjects. The three-dimensional (3D) geometry of carotid artery bifurcation was reconstructed from computed tomography angiography (CTA) images of Chinese control subjects (n = 30) and patients with carotid artery disease (n = 30). We defined two novel vector angles (i.e., angles 1 and 2) that were tangential to the reconstructed contour of the 3D vessel. The best-fit diameter was computed along the internal carotid artery (ICA) center line. Hemodynamic analysis was performed at various bifurcations. Patients with stenotic vessels have larger angles 1 and 2 (151 ± 11° and 42 ± 20°) and smaller diameters of the external carotid artery (ECA) (4.6 ± 0.85 mm) compared with control subjects (144 ± 13° and 36 ± 16°, 5.2 ± 0.57 mm) although there is no significant difference in the common carotid artery (CCA) (7.1 ± 1.2 vs. 7.5 ± 1.0 mm, P = 0.18). In particular, all patients with carotid artery disease have a stenosis at the proximal ICA (including both sinus and carina regions), while 20% of patients have stenosis at the middle ICA and 20% have stenosis expansion to the entire cervical ICA. Morphometric and hemodynamic analyses suggest that atherosclerotic plaques initiate at both sinus and carina regions of ICA and progress downstream.

  7. Textural Feature Selection for Enhanced Detection of Stationary Humans in Through the Wall Radar Imagery

    Science.gov (United States)

    2014-05-02

    b) (c) Figure 2. (a) Through-the-wall MIMO System. (b) Building used for Through-the-Wall Measurements (the dashed square indicates the...number of training samples at the parent node t and iQ is the number of training samples associated with the child node iv . The Gini index is a...also be determined by using the weighted average of the Gini index. The training samples are first sorted based on the values they take for the feature

  8. Human pentraxin 3 (PTX3 as a novel biomarker for the diagnosis of pulmonary arterial hypertension.

    Directory of Open Access Journals (Sweden)

    Yuichi Tamura

    Full Text Available BACKGROUND: Although inflammation is an important feature of pulmonary arterial hypertension (PAH, the usefulness of local inflammatory markers as biomarkers for PAH is unknown. In this study, we tested whether plasma concentrations of human pentraxin 3 (PTX3, a local inflammatory marker, would be a useful biomarker for detecting PAH. METHODS: Plasma PTX3 concentrations were evaluated in 50 PAH patients (27 with idiopathic PAH, 17 with PAH associated with connective tissue disease (CTD-PAH, and six with congenital heart disease, 100 age and sex-matched healthy controls, and 34 disease-matched CTD patients without PAH. Plasma concentrations of B-type natriuretic peptide (BNP and C-reactive protein (CRP were also determined. RESULTS: Mean PTX3 levels were significantly higher in all PAH patients than in the healthy controls (4.40±0.37 vs. 1.94±0.09 ng/mL, respectively; P<0.001. Using a threshold level of 2.84 ng/mL, PTX3 yielded a sensitivity of 74.0% and a specificity of 84.0% for the detection of PAH. In CTD-PAH patients, mean PTX3 concentrations were significantly higher than in CTD patients without PAH (5.02±0.69 vs. 2.40±0.14 ng/mL, respectively; P<0.001. There was no significant correlation between plasma levels of PTX3 and BNP or CRP. Receiver operating characteristic (ROC curves for screening PAH in patients with CTD revealed that PTX3 (area under the ROC curve 0.866 is superior to BNP. Using a PTX3 threshold of 2.85 ng/mL maximized true-positive and false-negative results (sensitivity 94.1%, specificity 73.5%. CONCLUSION: Plasma concentrations of PTX3 may be a better biomarker of PAH than BNP, especially in patients with CTD.

  9. Spectral characteristics of normal and atherosclerotic human coronary artery intima and media

    Science.gov (United States)

    Morcos, N. C.; Levy, Guy C.; Rizoiu, Ioana-Mihaela; Tomita, M.

    1994-07-01

    Efficient use and specific targeting of laser energy to atherosclerotic lesions necessitate understanding of spectral characteristics of intima and media from normal and diseased segments. We report absorption, transmission, and reflectance spectra from 19 normal and 21 diseased coronary artery segments which were obtained at autopsy within 5 to 10 h post mortem and submerged in oxygenated Ringer's solution. Spectra were obtained from the luminal surface of 1 X 1 cm full thickness arteries or bluntly dissected intima and media segments in the range 250 to 2500 nm. Water peaks were subtracted. Absorption and transmission for full thickness artery, intima, and media from normal and atherosclerotic arteries shared main bands at 1150 and 1700 nm with variation in intensity. Significant differences in reflectance showed bands at 1080, 1340, 1600, 1739 nm in normal intima and media and atherosclerotic intima but absent in media from atherosclerotic arteries. Peaks at 1340, 1600, and 1739 nm in normal intima and media are equalized in atherosclerotic intima and absent in atherosclerotic media. In conclusion, absence of reflectance at 1080, 1340, 1600, and 1739 nm in atherosclerotic media may be selectively utilized to target laser energy and ablation at intimal plaque and spare media of atherosclerotic arteries.

  10. Could Peripheral Arterial Disease Be Your Problem?

    Science.gov (United States)

    ... exercise and yoga classes and has returned to teaching. Fast Facts Peripheral arterial disease (P.A.D.) occurs when a fatty material called plaque (pronounced plak) builds up on the inside walls of the arteries that carry blood from ...

  11. Translating the microRNA signature of microvesicles derived from human coronary artery smooth muscle cells in patients with familial hypercholesterolemia and coronary artery disease.

    Science.gov (United States)

    de Gonzalo-Calvo, David; Cenarro, Ana; Garlaschelli, Katia; Pellegatta, Fabio; Vilades, David; Nasarre, Laura; Camino-Lopez, Sandra; Crespo, Javier; Carreras, Francesc; Leta, Rubén; Catapano, Alberico Luigi; Norata, Giuseppe Danilo; Civeira, Fernando; Llorente-Cortes, Vicenta

    2017-05-01

    To analyze the impact of atherogenic lipoproteins on the miRNA signature of microvesicles derived from human coronary artery smooth muscle cells (CASMC) and to translate these results to familial hypercholesterolemia (FH) and coronary artery disease (CAD) patients. Conditioned media was collected after exposure of CASMC to atherogenic lipoproteins. Plasma samples were collected from two independent populations of diagnosed FH patients and matched normocholesterolemic controls (Study population 1, N=50; Study population 2, N=24) and a population of patients with suspected CAD (Study population 3, N=50). Extracellular vesicles were isolated and characterized using standard techniques. A panel of 30 miRNAs related to vascular smooth muscle cell (VSMC) (patho-)physiology was analyzed using RT-qPCR. Atherogenic lipoproteins significantly reduced levels of miR-15b-5p, -24-3p, -29b-3p, -130a-3p, -143-3p, -146a-3p, -222-3p, -663a levels (Pmicrovesicles (0.1μm-1μm in diameter) released by CASMC. Two of these miRNAs, miR-24-3p and miR-130a-3p, were reduced in circulating microvesicles from FH patients compared with normocholesterolemic controls in a pilot study (Study population 1) and in different validation studies (Study populations 1 and 2) (Pmicrovesicles and these alterations are reflected in patients with FH. Circulating miR-130a-3p emerges as a potential biomarker for coronary atherosclerosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Integration of multi-modality imaging for accurate 3D reconstruction of human coronary arteries in vivo

    Science.gov (United States)

    Giannoglou, George D.; Chatzizisis, Yiannis S.; Sianos, George; Tsikaderis, Dimitrios; Matakos, Antonis; Koutkias, Vassilios; Diamantopoulos, Panagiotis; Maglaveras, Nicos; Parcharidis, George E.; Louridas, George E.

    2006-12-01

    In conventional intravascular ultrasound (IVUS)-based three-dimensional (3D) reconstruction of human coronary arteries, IVUS images are arranged linearly generating a straight vessel volume. However, with this approach real vessel curvature is neglected. To overcome this limitation an imaging method was developed based on integration of IVUS and biplane coronary angiography (BCA). In 17 coronary arteries from nine patients, IVUS and BCA were performed. From each angiographic projection, a single end-diastolic frame was selected and in each frame the IVUS catheter was interactively detected for the extraction of 3D catheter path. Ultrasound data was obtained with a sheath-based catheter and recorded on S-VHS videotape. S-VHS data was digitized and lumen and media-adventitia contours were semi-automatically detected in end-diastolic IVUS images. Each pair of contours was aligned perpendicularly to the catheter path and rotated in space by implementing an algorithm based on Frenet-Serret rules. Lumen and media-adventitia contours were interpolated through generation of intermediate contours creating a real 3D lumen and vessel volume, respectively. The absolute orientation of the reconstructed lumen was determined by back-projecting it onto both angiographic planes and comparing the projected lumen with the actual angiographic lumen. In conclusion, our method is capable of performing rapid and accurate 3D reconstruction of human coronary arteries in vivo. This technique can be utilized for reliable plaque morphometric, geometrical and hemodynamic analyses.

  13. Pulmonary vein and atrial wall pathology in human total anomalous pulmonary venous connection

    NARCIS (Netherlands)

    Douglas, Yvonne L.; Jongbloed, Monique R. M.; den Hartog, Wietske C. E.; Bartelings, Margot M.; Bogers, Ad J. J. C.; Ebels, Tjark; DeRuiter, Marco C.; Gittenberger-de Groot, Adriana C.

    2009-01-01

    Background: Normally, the inside of the left atrial (LA) body and pulmonary veins (PVs) is lined by vessel wall tissue covered by myocardium. In total anomalous pulmonary venous connection (TAPVC), no connection of the PVs with the LA body exists. These veins have an increased incidence of PV

  14. Nuclear IL-33 regulates soluble ST2 receptor and IL-6 expression in primary human arterial endothelial cells and is decreased in idiopathic pulmonary arterial hypertension.

    Science.gov (United States)

    Shao, Dongmin; Perros, Frédéric; Caramori, Gaetano; Meng, Chao; Dormuller, Peter; Chou, Pai-Chien; Church, Colin; Papi, Alberto; Casolari, Paolo; Welsh, David; Peacock, Andrew; Humbert, Marc; Adcock, Ian M; Wort, Stephen J

    2014-08-15

    Idiopathic pulmonary arterial hypertension (IPAH) is an incurable condition leading to right ventricular failure and death and inflammation is postulated to be associated with vascular remodelling. Interleukin (IL)-33, a member of the "alarmin" family can either act on the membrane ST2 receptor or as a nuclear repressor, to regulate inflammation. We show, using immunohistochemistry, that IL-33 expression is nuclear in the vessels of healthy subjects whereas nuclear IL-33 is markedly diminished in the vessels of IPAH patients. This correlates with reduced IL-33 mRNA expression in their lung. In contrast, serum levels of IL-33 are unchanged in IPAH. However, the expression of the soluble form of ST2, sST2, is enhanced in the serum of IPAH patients. Knock-down of IL-33 in human endothelial cells (ECs) using siRNA is associated with selective modulation of inflammatory genes involved in vascular remodelling including IL-6. Additionally, IL-33 knock-down significantly increased sST2 release from ECs. Chromatin immunoprecipitation demonstrated that IL-33 bound multiple putative homeodomain protein binding motifs in the proximal and distal promoters of ST2 genes. IL-33 formed a complex with the histone methyltransferase SUV39H1, a transcriptional repressor. In conclusion, IL-33 regulates the expression of IL-6 and sST2, an endogenous IL-33 inhibitor, in primary human ECs and may play an important role in the pathogenesis of PAH through recruitment of transcriptional repressor proteins.

  15. Effects of Pulsatile Pressure on Stress Distributionin Artery Wall at in Vivo Longitudinal Limit Constraint%脉动血压对在体轴向极限强约束血管壁应力分布的影响

    Institute of Scientific and Technical Information of China (English)

    陈泳; 覃开蓉; 滕忠照; 柳兆荣

    2000-01-01

    本文详细分析正弦脉动压力载荷对动脉管壁应力分布的影响。结果表明,对某确定时刻,包含在运动方程中的惯性项对血管壁应力的影响很小,可忽略不计;在体轴向极限强约束下,血管壁周向应力随时间的变化曲线与压力曲线同相位和同周期,而且振幅不随频率的快慢而改变。一个心动周期内,血管内、外壁处周向应力随时间变化的平均值只与脉动压力载荷的平均值有关,而振幅主要与脉压有关,在内壁处随平均压的改变有一定变化,但在外壁处受平均压的影响很小。%In this paper, the effects of the sinusoidal pulsatile pressure on the stress distribution in the artery wall will be studied. Results show that the acceleration term in the equation of motion has little influence on the stress in the artery wall, and can be ignored. At in vivo longitudinal limit constraint, the variation of the circumferential stress with time have the same phase and period with the curves of the pulsatile pressure, and the amplitudes have no change with the frequency. During a cardiac cycle, the mean circumferential stress in the inner and outer wall only relates to the mean pressure, and the pulsatile stress value is mainly connected with the pulsatile pressure. The change of mean pressure has some influence to the pulsatile value in the inner wall, and little influence in the outer wall.

  16. Reconstruction of the abdominal wall by using a combination of the human acellular dermal matrix implant and an interpositional omentum flap after extensive tumor resection in patients with abdominal wall neoplasm:A preliminary result

    Institute of Scientific and Technical Information of China (English)

    Yan Gu; Rui Tang; Ding-Quan Gong; Yun-Liang Qian

    2008-01-01

    AIM:To present our trial using a combination of the human acellular dermal matrix (HADM) implant and an interpositional omentum flap to repair giant abdominal wall defects after extensive tumor resection.METHODS:Between February and October of 2007,three patients with giant defects of the abdominal wall after extensive tumor resection underwent reconstruction with a combination of HADM and omentum flap.Postoperative morbidities and signs of herniation were monitored.RESULTS:The abdominal wall reconstruction was successful in these three patients,there was no severe morbidity and no signs of herniation in the follow-up period.CONCLUSION:The combination of HADM and omentum flap offers a new,safe and effective alternative to traditional forms in the repair of giant abdominal wall defects.Further analysis of the long-term outcome and more cases are needed to assess the reliability of this technique.

  17. Activation of endothelial and epithelial KCa2.3 calcium-activated potassium channels by NS309 relaxes human small pulmonary arteries and bronchioles

    DEFF Research Database (Denmark)

    Kroigaard, Christel; Dalsgaard, Thomas; Nielsen, Gorm

    2012-01-01

    BACKGROUND AND PURPOSE: Small (K(Ca) 2) and intermediate (K(Ca) 3.1) conductance calcium-activated potassium channels (K(Ca) ) may contribute to both epithelium- and endothelium-dependent relaxations, but this has not been established in human pulmonary arteries and bronchioles. Therefore, we...... investigated the expression of K(Ca) 2.3 and K(Ca) 3.1 channels, and hypothesized that activation of these channels would produce relaxation of human bronchioles and pulmonary arteries. EXPERIMENTAL APPROACH: Channel expression and functional studies were conducted in human isolated small pulmonary arteries.......1 activator, NS309, induced concentration-dependent relaxations. NS309 was equally potent in relaxing pulmonary arteries, but less potent in bronchioles, than salbutamol. NS309 relaxations were blocked by the K(Ca) 2 channel blocker apamin, while the K(Ca) 3.1 channel blocker, charybdotoxin failed to reduce...

  18. The Senescence Process of Internal Thoracic Artery

    Directory of Open Access Journals (Sweden)

    Francesco Rivasi

    2013-04-01

    Full Text Available OBJECTIVE. The Internal Thoracic Artery (ITA is the most widely used arterial conduit for coronary artery by-pass, because it is very rarely affected by atherosclerosis. However, the state of its wall at the time of grafting procedure could influence the long-term outcome of coronary artery by-pass. METHODS. We have investigated 20 specimens of distal human ITA, derived from 14 male patients and 6 female patients, aged between 68 and 77 years, operated for atherosclerotic coronary artery disease. The specimens, collected after surgical skeletonization during coronary artery by-pass procedures, were fixed in 10% neutral buffered formalin and then paraffin embedded. Besides to haematoxylin-eosin, histochemistry for elastic fibers (Weigert‘s staining, Van Gieson‘s staining, Verhoeff‘s staining and immunohistochemistry for muscle cells (smooth muscle actin, caldesmon, desmin and CD34 have been performed, applying the standard avidin-biotin complex (ABC method. RESULTS. A degenerative pathology, most likely due to aging, characterized by the fragmentation of the internal and external elastic membranes and by the consumption of the elastic network of the tunica media has been microscopically observed in a quarter of our patients, without the achievement of classical signs of overt atherosclerosis (cholesterol deposition, lipidic infiltration, endothelial ulceration, intimal calcification, which could compromise the long-term patency of the graft. CONCLUSIONS. The degenerative change is followed by a remodelling process, based on the proliferation of unspecialized muscle like cells, able to preserve the architecture and the stability of the arterial wall and consequently its functional long-term behaviour. [J Interdiscipl Histopathol 2013; 1(2.000: 58-61

  19. Middle cerebral artery diameter changes during rhythmic handgrip exercise in humans.

    Science.gov (United States)

    Verbree, J; Bronzwaer, Agt; van Buchem, M A; Daemen, Mjap; van Lieshout, J J; van Osch, Mjp

    2017-08-01

    Transcranial Doppler (TCD) sonography is a frequently employed technique for quantifying cerebral blood flow by assuming a constant arterial diameter. Given that exercise increases arterial pressure by sympathetic activation, we hypothesized that exercise might induce a change in the diameter of large cerebral arteries. Middle cerebral artery (MCA) cross-sectional area was assessed in response to handgrip exercise by direct magnetic resonance imaging (MRI) observations. Twenty healthy subjects (11 female) performed three 5 min bouts of rhythmic handgrip exercise at 60% maximum voluntary contraction, alternated with 5 min of rest. High-resolution 7 T MRI scans were acquired perpendicular to the MCA. Two blinded observers manually determined the MCA cross-sectional area. Sufficient image quality was obtained in 101 MCA-scans of 19 subjects (age-range 20-59 years). Mixed effects modelling showed that the MCA cross-sectional area decreased by 2.1 ± 0.8% (p = 0.01) during handgrip, while the heart rate increased by 11 ± 2% (p exercise. This further strengthens the current concept of sympathetic control of large cerebral arteries, showing in vivo vasoconstriction during exercise-induced sympathetic activation. Moreover, care must be taken when interpreting TCD exercise studies as diameter constancy cannot be assumed.

  20. Biomechanics of Ergometric Stress Test: regional and local effects on elastic, transitional and muscular human arteries

    Science.gov (United States)

    Valls, G.; Torrado, J.; Farro, I.; Bia, D.; Zócalo, Y.; Lluberas, S.; Craiem, D.; Armentano, Rl

    2011-09-01

    Ergometric exercise stress tests (EST) give important information about the cardiovascular (CV) response to increased demands. The expected EST-related changes in variables like blood pressure and heart rate are known, but those in the arterial biomechanics are controversial and incompletely characterized. In this context, this work aims were to characterize the regional and local arterial biomechanical behaviour in response to EST; to evaluate its temporal profile in the post-EST recovery phase; and to compare the biomechanical response of different to EST. Methods: In 16 non-trained healthy young subjects the carotid-femoral pulse wave velocity and the carotid, femoral and brachial arterial distensibility were non-invasively evaluated before (Rest) and after EST. Main results: The EST resulted in an early increase in the arterial stiffness, evidenced by both, regional and local parameters (pulse wave velocity increase and distensibility reduction). When analyzing conjunctly the different post-EST recovery stages there were quali-quantitative differences among the arterial local stiffness response to EST. The biomechanical changes could not be explained only by blood pressure variations.

  1. The dynamics of pulsatile flow in distensible model arteries.

    Science.gov (United States)

    Liepsch, D W; Zimmer, R

    1995-12-01

    Deposits and blockages are often found in the carotid, coronary, renal and femoral arteries. This paper deals with laser-Doppler velocity measurements in models of bifurcations of the human femoral arteries. Several models were prepared for the studies: a simplified 35 degrees glass model, two elastic-silicone-rubber models with a wall thickness of 1 mm and 2 mm, and true-to-scale rigid and elastic models. These measurements give a clearer picture of how hemodynamics influences the formation of atherosclerotic plaques where there is a hardening of the arterial walls and a loss of elasticity. In addition to the effects of elasticity, the influence of the flow's pulsatility were studied. The measurements were done in steady and pulsatile flow. From the velocity measurements the shear stresses were calculated.

  2. Retrograde arterial leg blood flow during tilt-back from a head-up posture: importance of capacitive flows when arterial pressure changes.

    Science.gov (United States)

    Sheriff, Don D; Nådland, Inger Helene; Toska, Karin

    2010-03-01

    The windkessel function of the arterial system converts the intermittent action of the heart into more continuous microcirculatory blood flow during diastole via the return of elastic energy stored in the walls of the arteries during systole. Might the same phenomenon occur regionally within the arterial system during tilting owing to regional differences in local arterial pressure imposed by gravity? We sought to test the hypothesis that during tilt-back from a head-up posture, the return of stored elastic energy in leg arteries would work to slow, or perhaps transiently reverse, the flow of blood in the femoral artery. Femoral artery blood flow and arterial pressure were recorded during tilt back from a 30 degrees head-up posture to supine (approximately 0.5 G) in young, healthy subjects (n = 7 males and 3 females) before and during clonidine infusion. During control (no drug) conditions femoral artery blood flow ceased for an entire heart beat during tilt-back. During clonidine infusion femoral artery blood flow reversed for at least one entire heart beat during tilt-back, i.e., blood flow in the retrograde direction in the femoral artery from the leg into the abdomen. Thus substantial capacitive effects of tilting on leg blood flow occur in humans during mild changes in posture.

  3. Isolate-dependent growth, virulence, and cell wall composition in the human pathogen Aspergillus fumigatus.

    Directory of Open Access Journals (Sweden)

    Nansalmaa Amarsaikhan

    Full Text Available The ubiquitous fungal pathogen Aspergillus fumigatus is a mediator of allergic sensitization and invasive disease in susceptible individuals. The significant genetic and phenotypic variability between and among clinical and environmental isolates are important considerations in host-pathogen studies of A. fumigatus-mediated disease. We observed decreased radial growth, rate of germination, and ability to establish colony growth in a single environmental isolate of A. fumigatus, Af5517, when compared to other clinical and environmental isolates. Af5517 also exhibited increased hyphal diameter and cell wall β-glucan and chitin content, with chitin most significantly increased. Morbidity, mortality, lung fungal burden, and tissue pathology were decreased in neutropenic Af5517-infected mice when compared to the clinical isolate Af293. Our results support previous findings that suggest a correlation between in vitro growth rates and in vivo virulence, and we propose that changes in cell wall composition may contribute to this phenotype.

  4. Mechanism of synchronized change in ultrasonic integrated backscatter across human heart wall

    Science.gov (United States)

    Tobinai, Yumi; Taki, Hirofumi; Kanai, Hiroshi

    2017-07-01

    Ultrasonic integrated backscatter (IB) from the heart wall, which has been employed for quantitative tissue characterization of the myocardium, is known to have cyclic variation-a decrease in systole and an increase in diastole. In the present study, by tracking the measurement position of the myocardium and compensating for the movement due to the heartbeat, IB and its temporal variation were obtained from the same site with a high temporal resolution of 1.73 ms. In an in vivo study on a healthy subject, the temporal variation of IB values homogeneously changed across the heart wall, especially during the slow filling and the atrial systole phases. This new finding shows that the IB value reflects a small movement of the myocardium of about 5 mm/s. Thus, the proposed measurement has a potential for quantitative and accurate evaluation of the contraction and relaxation of the myocardium.

  5. Anatomic distribution of nerves and microvascular density in the human anterior vaginal wall: prospective study.

    Directory of Open Access Journals (Sweden)

    Ting Li

    Full Text Available BACKGROUND: The presence of the G-spot (an assumed erotic sensitive area in the anterior wall of the vagina remains controversial. We explored the histomorphological basis of the G-spot. METHODS: Biopsies were drawn from a 12 o'clock direction in the distal- and proximal-third areas of the anterior vagina of 32 Chinese subjects. The total number of protein gene product 9.5-immunoreactive nerves and smooth muscle actin-immunoreactive blood vessels in each specimen was quantified using the avidin-biotin-peroxidase assay. RESULTS: Vaginal innervation was observed in the lamina propria and muscle layer of the anterior vaginal wall. The distal-third of the anterior vaginal wall had significantly richer small-nerve-fiber innervation in the lamina propria than the proximal-third (p = 0.000 and in the vaginal muscle layer (p = 0.006. There were abundant microvessels in the lamina propria and muscle layer, but no small vessels in the lamina propria and few in the muscle layer. Significant differences were noted in the number of microvessels when comparing the distal- with proximal-third parts in the lamina propria (p = 0.046 and muscle layer (p = 0.002. CONCLUSIONS: Significantly increased density of nerves and microvessels in the distal-third of the anterior vaginal wall could be the histomorphological basis of the G-spot. Distal anterior vaginal repair could disrupt the normal anatomy, neurovascular supply and function of the G-spot, and cause sexual dysfunction.

  6. The spatial arrangement of the human large intestinal wall blood circulation

    Science.gov (United States)

    Kachlik, David; Baca, Vaclav; Stingl, Josef

    2010-01-01

    The aim of the study was to describe and depict the spatial arrangement of the colon microcirculatory bed as a whole. Various parts of the large intestine and terminal ileum were harvested from either cadaver or section material or gained peroperatively. Samples were then injected with India ink or methylmetacrylate Mercox resin for microdissection and corrosion casting for scanning electron microscopy. The results showed that extramural vasa recta ramified to form the subserous plexus, some of them passing underneath the colon taeniae. Branches of both short and long vasa recta merged in the colon wall, pierced the muscular layer and spread out as the submucous plexus, which extended throughout the whole intestine without any interruption. The muscular layer received blood via both the centrifugal branches of the submucous plexus and the minor branches sent off by the subserous plexus. The mucosa was supplied by the mucous plexus, which sent capillaries into the walls of intestinal glands. The hexagonal arrangement of the intestinal glands reflected their vascular bed. All three presumptive critical points are only gross anatomical points of no physiological relevance in healthy individuals. Neither microscopic weak points nor regional differences were proven within the wall of the whole large intestine. The corrosion casts showed a huge density of capillaries under the mucosa of the large intestine. A regular hexagonal pattern of the vascular bed on the inner surface was revealed. No microvascular critical point proofs were confirmed and a correlation model to various pathological states was created. PMID:20447248

  7. Through Wall Radar Classification of Human Micro-Doppler Using Singular Value Decomposition Analysis.

    Science.gov (United States)

    Ritchie, Matthew; Ash, Matthew; Chen, Qingchao; Chetty, Kevin

    2016-08-31

    The ability to detect the presence as well as classify the activities of individuals behind visually obscuring structures is of significant benefit to police, security and emergency services in many situations. This paper presents the analysis from a series of experimental results generated using a through-the-wall (TTW) Frequency Modulated Continuous Wave (FMCW) C-Band radar system named Soprano. The objective of this analysis was to classify whether an individual was carrying an item in both hands or not using micro-Doppler information from a FMCW sensor. The radar was deployed at a standoff distance, of approximately 0.5 m, outside a residential building and used to detect multiple people walking within a room. Through the application of digital filtering, it was shown that significant suppression of the primary wall reflection is possible, significantly enhancing the target signal to clutter ratio. Singular Value Decomposition (SVD) signal processing techniques were then applied to the micro-Doppler signatures from different individuals. Features from the SVD information have been used to classify whether the person was carrying an item or walking free handed. Excellent performance of the classifier was achieved in this challenging scenario with accuracies up to 94%, suggesting that future through wall radar sensors may have the ability to reliably recognize many different types of activities in TTW scenarios using these techniques.

  8. Through Wall Radar Classification of Human Micro-Doppler Using Singular Value Decomposition Analysis

    Directory of Open Access Journals (Sweden)

    Matthew Ritchie

    2016-08-01

    Full Text Available The ability to detect the presence as well as classify the activities of individuals behind visually obscuring structures is of significant benefit to police, security and emergency services in many situations. This paper presents the analysis from a series of experimental results generated using a through-the-wall (TTW Frequency Modulated Continuous Wave (FMCW C-Band radar system named Soprano. The objective of this analysis was to classify whether an individual was carrying an item in both hands or not using micro-Doppler information from a FMCW sensor. The radar was deployed at a standoff distance, of approximately 0.5 m, outside a residential building and used to detect multiple people walking within a room. Through the application of digital filtering, it was shown that significant suppression of the primary wall reflection is possible, significantly enhancing the target signal to clutter ratio. Singular Value Decomposition (SVD signal processing techniques were then applied to the micro-Doppler signatures from different individuals. Features from the SVD information have been used to classify whether the person was carrying an item or walking free handed. Excellent performance of the classifier was achieved in this challenging scenario with accuracies up to 94%, suggesting that future through wall radar sensors may have the ability to reliably recognize many different types of activities in TTW scenarios using these techniques.

  9. The spatial arrangement of the human large intestinal wall blood circulation.

    Science.gov (United States)

    Kachlik, David; Baca, Vaclav; Stingl, Josef

    2010-03-01

    The aim of the study was to describe and depict the spatial arrangement of the colon microcirculatory bed as a whole. Various parts of the large intestine and terminal ileum were harvested from either cadaver or section material or gained peroperatively. Samples were then injected with India ink or methylmetacrylate Mercox resin for microdissection and corrosion casting for scanning electron microscopy. The results showed that extramural vasa recta ramified to form the subserous plexus, some of them passing underneath the colon taeniae. Branches of both short and long vasa recta merged in the colon wall, pierced the muscular layer and spread out as the submucous plexus, which extended throughout the whole intestine without any interruption. The muscular layer received blood via both the centrifugal branches of the submucous plexus and the minor branches sent off by the subserous plexus. The mucosa was supplied by the mucous plexus, which sent capillaries into the walls of intestinal glands. The hexagonal arrangement of the intestinal glands reflected their vascular bed. All three presumptive critical points are only gross anatomical points of no physiological relevance in healthy individuals. Neither microscopic weak points nor regional differences were proven within the wall of the whole large intestine. The corrosion casts showed a huge density of capillaries under the mucosa of the large intestine. A regular hexagonal pattern of the vascular bed on the inner surface was revealed. No microvascular critical point proofs were confirmed and a correlation model to various pathological states was created.

  10. The effect of pH and ion channel modulators on human placental arteries.

    Directory of Open Access Journals (Sweden)

    Tayyba Y Ali

    Full Text Available Chorionic plate arteries (CPA are located at the maternofetal interface where they are able to respond to local metabolic changes. Unlike many other types of vasculature, the placenta lacks nervous control and requires autoregulation for controlling blood flow. The placental circulation, which is of low-resistance, may become hypoxic easily leading to fetal acidosis and fetal distress however the role of the ion channels in these circumstances is not well-understood. Active potassium channel conductances that are subject to local physicochemical modulation may serve as pathways through which such signals are transduced. The aim of this study was to investigate the modulation of CPA by pH and the channels implicated in these responses using wire myography. CPA were isolated from healthy placentae and pre-contracted with U46619 before testing the effects of extracellular pH using 1 M lactic acid over the pH range 7.4-6.4 in the presence of a variety of ion channel modulators. A change from pH 7.4 to 7.2 produced a 29±3% (n = 9 relaxation of CPA which increased to 61±4% at the lowest pH of 6.4. In vessels isolated from placentae of women with pre-eclampsia (n = 6, pH responses were attenuated. L-methionine increased the relaxation to 67±7% (n = 6; p<0.001 at pH 6.4. Similarly the TASK 1/3 blocker zinc chloride (1 mM gave a maximum relaxation of 72±5% (n = 8; p<0.01 which compared with the relaxation produced by the TREK-1 opener riluzole (75±5%; n = 6. Several other modulators induced no significant changes in vascular responses. Our study confirmed expression of several ion channel subtypes in CPA with our results indicating that extracellular pH within the physiological range has an important role in controlling vasodilatation in the human term placenta.

  11. Investigation of dynamic SPECT measurements of the arterial input function in human subjects using simulation, phantom and human studies

    Science.gov (United States)

    Winant, Celeste D.; Aparici, Carina Mari; Zelnik, Yuval R.; Reutter, Bryan W.; Sitek, Arkadiusz; Bacharach, Stephen L.; Gullberg, Grant T.

    2012-01-01

    Computer simulations, a phantom study and a human study were performed to determine whether a slowly rotating single-photon computed emission tomography (SPECT) system could provide accurate arterial input functions for quantification of myocardial perfusion imaging using kinetic models. The errors induced by data inconsistency associated with imaging with slow camera rotation during tracer injection were evaluated with an approach called SPECT/P (dynamic SPECT from positron emission tomography (PET)) and SPECT/D (dynamic SPECT from database of SPECT phantom projections). SPECT/P simulated SPECT-like dynamic projections using reprojections of reconstructed dynamic 94Tc-methoxyisobutylisonitrile (94Tc-MIBI) PET images acquired in three human subjects (1 min infusion). This approach was used to evaluate the accuracy of estimating myocardial wash-in rate parameters K1 for rotation speeds providing 180° of projection data every 27 or 54 s. Blood input and myocardium tissue time-activity curves (TACs) were estimated using spatiotemporal splines. These were fit to a one-compartment perfusion model to obtain wash-in rate parameters K1. For the second method (SPECT/D), an anthropomorphic cardiac torso phantom was used to create real SPECT dynamic projection data of a tracer distribution derived from 94Tc-MIBI PET scans in the blood pool, myocardium, liver and background. This method introduced attenuation, collimation and scatter into the modeling of dynamic SPECT projections. Both approaches were used to evaluate the accuracy of estimating myocardial wash-in parameters for rotation speeds providing 180° of projection data every 27 and 54 s. Dynamic cardiac SPECT was also performed in a human subject at rest using a hybrid SPECT/CT scanner. Dynamic measurements of 99mTc-tetrofosmin in the myocardium were obtained using an infusion time of 2 min. Blood input, myocardium tissue and liver TACs were estimated using the same spatiotemporal splines. The spatiotemporal maximum

  12. Investigation of dynamic SPECT measurements of the arterial input function in human subjects using simulation, phantom and human studies.

    Science.gov (United States)

    Winant, Celeste D; Aparici, Carina Mari; Zelnik, Yuval R; Reutter, Bryan W; Sitek, Arkadiusz; Bacharach, Stephen L; Gullberg, Grant T

    2012-01-21

    Computer simulations, a phantom study and a human study were performed to determine whether a slowly rotating single-photon computed emission tomography (SPECT) system could provide accurate arterial input functions for quantification of myocardial perfusion imaging using kinetic models. The errors induced by data inconsistency associated with imaging with slow camera rotation during tracer injection were evaluated with an approach called SPECT/P (dynamic SPECT from positron emission tomography (PET)) and SPECT/D (dynamic SPECT from database of SPECT phantom projections). SPECT/P simulated SPECT-like dynamic projections using reprojections of reconstructed dynamic (94)Tc-methoxyisobutylisonitrile ((94)Tc-MIBI) PET images acquired in three human subjects (1 min infusion). This approach was used to evaluate the accuracy of estimating myocardial wash-in rate parameters K(1) for rotation speeds providing 180° of projection data every 27 or 54 s. Blood input and myocardium tissue time-activity curves (TACs) were estimated using spatiotemporal splines. These were fit to a one-compartment perfusion model to obtain wash-in rate parameters K(1). For the second method (SPECT/D), an anthropomorphic cardiac torso phantom was used to create real SPECT dynamic projection data of a tracer distribution derived from (94)Tc-MIBI PET scans in the blood pool, myocardium, liver and background. This method introduced attenuation, collimation and scatter into the modeling of dynamic SPECT projections. Both approaches were used to evaluate the accuracy of estimating myocardial wash-in parameters for rotation speeds providing 180° of projection data every 27 and 54 s. Dynamic cardiac SPECT was also performed in a human subject at rest using a hybrid SPECT/CT scanner. Dynamic measurements of (99m)Tc-tetrofosmin in the myocardium were obtained using an infusion time of 2 min. Blood input, myocardium tissue and liver TACs were estimated using the same spatiotemporal splines. The

  13. Influence of radiographic contrast media on the nitric oxide release from human arterial and venous endothelial cells on extracellular matrix.

    Science.gov (United States)

    Franke, R P; Fuhrmann, R; Jung, F

    2013-01-01

    Radiographic contrast media (RCM) can vary widely in their physicochemical properties, e.g. the iodine concentration, osmolality, molecule structure, chemotoxicity, hydrophilicity, electric charge and viscosity. Besides the necessary effect of Roentgen ray absorption, which provides contrast-rich images of vessels, RCMs can have varying adverse effects. As one possible cause of microcirculatory disorders, changes in morphology and function of endothelial cells are discussed. Therefore, RCM media-induced release of nitric oxide from arterial as well as from venous endothelial cells in contact with two commercially available RCMs (Iodixanol and Iomeprol) was investigated. NO concentrations started to increase slightly in the HUVEC control cultures after 3 min incubation time, however, NO concentrations in the cultures incubated with Iomeprol 350 and Iodixanol 320 did not change over time (Iomeprol 350: p = 0.4905; Iodixanol 320: p = 0.784). On the whole, the time-dependent NO release differed for the three groups (RCM × time: p = 0.00224). This difference was due to the fact that, after incubation with the two contrast agents (Iodixanol 320: p = 0.0003; Iomeprol 350: p = 0.0168), less NO was released by the exposed HUVEC at 3 minutes and after 12 hours than by the control cells. In the control cultures of arterial endothelial cells as well as in cultures incubated with 30% v/v Iodixanol supplemented culture medium the NO release did not change. In those cultures of arterial endothelial cells supplemented with 30% v/v Iomeprol the NO release was significantly less than in control cultures and in cultures supplemented with Iodixanol (p = 0.021; p = 0.043). Inspite of a missing shear stress in our static plane vessel wall model there was a RCM-dependent difference in NO release from endothelial cells in vitro. The NO release from venous endothelial cells differed significantly from the NO release from arterial endothelial cells. While the administration of Iomeprol

  14. Mycobacterium tuberculosis Cell Wall Fragments Released upon Bacterial Contact with the Human Lung Mucosa Alter the Neutrophil Response to Infection

    Science.gov (United States)

    Scordo, Julia M.; Arcos, Jesús; Kelley, Holden V.; Diangelo, Lauren; Sasindran, Smitha J.; Youngmin, Ellie; Wewers, Mark D.; Wang, Shu-Hua; Balada-Llasat, Joan-Miquel; Torrelles, Jordi B.

    2017-01-01

    In 2016, the World Health Organization reported that one person dies of tuberculosis (TB) every 21 s. A host environment that Mycobacterium tuberculosis (M.tb) finds during its route of infection is the lung mucosa bathing the alveolar space located in the deepest regions of the lungs. We published that human lung mucosa, or alveolar lining fluid (ALF), contains an array of hydrolytic enzymes that can significantly alter the M.tb surface during infection by cleaving off parts of its cell wall. This interaction results in two different outcomes: modifications on the M.tb cell wall surface and release of M.tb cell wall fragments into the environment. Typically, one of the first host immune cells at the site of M.tb infection is the neutrophil. Neutrophils can mount an extracellular and intracellular innate immune response to M.tb during infection. We hypothesized that exposure of neutrophils to ALF-induced M.tb released cell wall fragments would prime neutrophils to control M.tb infection better. Our results show that ALF fragments activate neutrophils leading to an increased production of inflammatory cytokines and oxidative radicals. However, neutrophil exposure to these fragments reduces production of chemoattractants (i.e., interleukin-8), and degranulation, with the subsequent reduction of myeloperoxidase release, and does not induce cytotoxicity. Unexpectedly, these ALF fragment-derived modulations in neutrophil activity do not further, either positively or negatively, contribute to the intracellular control of M.tb growth during infection. However, secreted products from neutrophils primed with ALF fragments are capable of regulating the activity of resting macrophages. These results indicate that ALF-induced M.tb fragments could further contribute to the control of M.tb growth and local killing by resident neutrophils by switching on the total oxidative response and limiting migration of neutrophils to the infection site. PMID:28373877

  15. Wall shear stress calculations based on 3D cine phase contrast MRI and computational fluid dynamics: A comparison study in healthy carotid arteries

    NARCIS (Netherlands)

    M. Cibiş (Merih); W.V. Potters (Wouter); F.J.H. Gijsen (Frank); H. Marquering (Henk); E. VanBavel (Ed); A.F.W. van der Steen (Ton); A.J. Nederveen (Aart); J.J. Wentzel (Jolanda)

    2014-01-01

    textabstractWall shear stress (WSS) is involved in many pathophysiological processes related to cardiovascular diseases, and knowledge of WSS may provide vital information on disease progression. WSS is generally quantified with computational fluid dynamics (CFD), but can also be calculated using

  16. The Non-Invasive Functional Tissue Characterization for Arteriosclerosis by Artery Wall Motion Analysis with Time Series High-Speed Echo Images and Continuous Spygmo-Manometer

    Science.gov (United States)

    2007-11-02

    Abstract- The evaluation method of arteriosclerosis has been established, but most of them are invasive way. In late years, non-invasive diagnostic...method for arteriosclerosis can be done by the diagnosis with high resolution echography. However, even this new diagnostic method can not diagnose...until beginning the morphologic changes of the arteries by stenosis. There is little value even if it could be detected the arteriosclerosis after the

  17. Time-course of ventilation, arterial and pulmonary CO(2) tension during CO (2) increase in humans.

    Science.gov (United States)

    Satoh, Toru; Okada, Yasumasa; Hara, Yasushi; Sakamaki, Fumio; Kyotani, Shingo; Tomita, Takeshi; Nagaya, Noritoshi; Nakanishi, Norifumi

    2012-01-01

    A change of ventilation (VE), PaCO( 2 ) (arterial CO( 2 ) tension) and PvCO( 2 ) (pulmonary arterial CO( 2 ) tension) with time was not evaluated precisely during exercise or CO( 2 ) rebreathing in humans. In this study, changes of these variables with time were fitted to exponential curves {y = Exp ( x/ T + A ) + k} and compared. When exercise pulmonary hemodynamics was examined in 15 cardiac patients to decide therapies, we asked the patients to undergo CO( 2 ) rebreathing using air with supplementation of consumed O( 2 ). Arterial and pulmonary blood was drawn every minute. During exercise, T was 28.2 ± 8.4 and 26.8 ± 12.4, and A was 0.80 ± 0.50 and 0.50 ± 0.90 in VE and PvCO( 2 ), respectively, with no statistical differences. During CO( 2 ) rebreathing, T was 18.6 ± 5.8, 41.8 ± 38.0 and 21.6 ± 9.7 and A was 0.39 ± 0.67, 1.64 ± 1.35 and 0.17 ± 0.83 in VE, PaCO( 2 ) and PvCO( 2 ), respectively, with statistical difference of PaCO( 2 ) from other variables, suggesting that VE and PvCO( 2 ) showed same mode of change according to time but PaCO( 2 ) did not.

  18. Egr-1 identifies neointimal remodeling and relates to progression in human pulmonary arterial hypertension

    NARCIS (Netherlands)

    van der Feen, Diederik E; Dickinson, Michael G; Bartelds, Beatrijs; Borgdorff, Marinus A J; Sietsma, Hannie; Lévy, Marilyne; Berger, Rolf M F

    BACKGROUND: Pulmonary arterial hypertension (PAH) is hallmarked by the development of neointimal lesions. The transcription factor Egr-1 seems to play a critical role in neointimal formation in experimental PAH and was identified as a putative target for intervention. In this study we investigated

  19. Egr-1 identifies neointimal remodeling and relates to progression in human pulmonary arterial hypertension

    NARCIS (Netherlands)

    van der Feen, Diederik E; Dickinson, Michael G; Bartelds, Beatrijs; Borgdorff, Marinus A J; Sietsma, Hannie; Lévy, Marilyne; Berger, Rolf M F

    2015-01-01

    BACKGROUND: Pulmonary arterial hypertension (PAH) is hallmarked by the development of neointimal lesions. The transcription factor Egr-1 seems to play a critical role in neointimal formation in experimental PAH and was identified as a putative target for intervention. In this study we investigated w

  20. Relationship between upper and lower limb conduit artery vasodilator function in humans

    NARCIS (Netherlands)

    Thijssen, D.H.J.; Rowley, N.; Padilla, J.; Simmons, G.H.; Laughlin, M.H.; Whyte, G.; Cable, N.T.; Green, D.J.

    2011-01-01

    Brachial artery flow-mediated dilation (FMD) is a strong predictor of future cardiovascular disease and is believed to represent a "barometer" of systemic endothelial health. Although a recent study [Padilla et al. Exp Biol Med (Maywood) 235: 1287-1291, 2010] in pigs confirmed a strong correlation b

  1. Pathology of Human Coronary and Carotid Artery Atherosclerosis and Vascular Calcification in Diabetes Mellitus.

    Science.gov (United States)

    Yahagi, Kazuyuki; Kolodgie, Frank D; Lutter, Christoph; Mori, Hiroyoshi; Romero, Maria E; Finn, Aloke V; Virmani, Renu

    2017-02-01

    The continuing increase in the prevalence of diabetes mellitus in the general population is predicted to result in a higher incidence of cardiovascular disease. Although the mechanisms of diabetes mellitus-associated progression of atherosclerosis are not fully understood, at clinical and pathological levels, there is an appreciation of increased disease burden and higher levels of arterial calcification in these subjects. Plaques within the coronary arteries of patients with diabetes mellitus generally exhibit larger necrotic cores and significantly greater inflammation consisting mainly of macrophages and T lymphocytes relative to patients without diabetes mellitus. Moreover, there is a higher incidence of healed plaque ruptures and positive remodeling in hearts from subjects with type 1 diabetes mellitus and type 2 diabetes mellitus, suggesting a more active atherogenic process. Lesion calcification in the coronary, carotid, and other arterial beds is also more extensive. Although the role of coronary artery calcification in identifying cardiovascular disease and predicting its outcome is undeniable, our understanding of how key hormonal and physiological alterations associated with diabetes mellitus such as insulin resistance and hyperglycemia influence the process of vascular calcification continues to grow. Important drivers of atherosclerotic calcification in diabetes mellitus include oxidative stress, endothelial dysfunction, alterations in mineral metabolism, increased inflammatory cytokine production, and release of osteoprogenitor cells from the marrow into the circulation. Our review will focus on the pathophysiology of type 1 diabetes mellitus- and type 2 diabetes mellitus-associated vascular disease with particular focus on coronary and carotid atherosclerotic calcification.

  2. Relationship between upper and lower limb conduit artery vasodilator function in humans

    NARCIS (Netherlands)

    Thijssen, D.H.J.; Rowley, N.; Padilla, J.; Simmons, G.H.; Laughlin, M.H.; Whyte, G.; Cable, N.T.; Green, D.J.

    2011-01-01

    Brachial artery flow-mediated dilation (FMD) is a strong predictor of future cardiovascular disease and is believed to represent a "barometer" of systemic endothelial health. Although a recent study [Padilla et al. Exp Biol Med (Maywood) 235: 1287-1291, 2010] in pigs confirmed a strong correlation b

  3. Exercise training and artery function in humans: nonresponse and its relationship to cardiovascular risk factors.

    Science.gov (United States)

    Green, Daniel J; Eijsvogels, Thijs; Bouts, Yvette M; Maiorana, Andrew J; Naylor, Louise H; Scholten, Ralph R; Spaanderman, Marc E A; Pugh, Christopher J A; Sprung, Victoria S; Schreuder, Tim; Jones, Helen; Cable, Tim; Hopman, Maria T E; Thijssen, Dick H J

    2014-08-15

    The objectives of our study were to examine 1) the proportion of responders and nonresponders to exercise training in terms of vascular function; 2) a priori factors related to exercise training-induced changes in conduit artery function, and 3) the contribution of traditional cardiovascular risk factors to exercise-induced changes in artery function. We pooled data from our laboratories involving 182 subjects who underwent supervised, large-muscle group, endurance-type exercise training interventions with pre-/posttraining measures of flow-mediated dilation (FMD%) to assess artery function. All studies adopted an identical FMD protocol (5-min ischemia, distal cuff inflation), contemporary echo-Doppler methodology, and observer-independent automated analysis. Linear regression analysis was used to identify factors contributing to changes in FMD%. We found that cardiopulmonary fitness improved, and weight, body mass index (BMI), cholesterol, and mean arterial pressure (MAP) decreased after training, while FMD% increased in 76% of subjects (P cardiovascular risk factors were not significantly related to changes in FMD% (P > 0.05). In conclusion, we found that, while some subjects do not demonstrate increases following exercise training, improvement in FMD% is present in those with lower pretraining body weight and endothelial function. Moreover, exercise training-induced change in FMD% did not correlate with changes in traditional cardiovascular risk factors, indicating that some cardioprotective effects of exercise training are independent of improvement in risk factors.

  4. Exercise training and artery function in humans: nonresponse and its relationship to cardiovascular risk factors.

    NARCIS (Netherlands)

    Green, D.J.; Eijsvogels, T.M.; Bouts, Y.M.; Maiorana, A.J.; Naylor, L.H.; Scholten, R.R.; Spaanderman, M.E.; Pugh, C.J.; Sprung, V.S.; Schreuder, T.H.; Jones, H.; Cable, T.; Hopman, M.T.E.; Thijssen, D.H.J.

    2014-01-01

    The objectives of our study were to examine 1) the proportion of responders and nonresponders to exercise training in terms of vascular function; 2) a priori factors related to exercise training-induced changes in conduit artery function, and 3) the contribution of traditional cardiovascular risk fa

  5. Computational model of collagen turnover in carotid arteries during hypertension.

    Science.gov (United States)

    Sáez, P; Peña, E; Tarbell, J M; Martínez, M A

    2015-02-01

    It is well known that biological tissues adapt their properties because of different mechanical and chemical stimuli. The goal of this work is to study the collagen turnover in the arterial tissue of hypertensive patients through a coupled computational mechano-chemical model. Although it has been widely studied experimentally, computational models dealing with the mechano-chemical approach are not. The present approach can be extended easily to study other aspects of bone remodeling or collagen degradation in heart diseases. The model can be divided into three different stages. First, we study the smooth muscle cell synthesis of different biological substances due to over-stretching during hypertension. Next, we study the mass-transport of these substances along the arterial wall. The last step is to compute the turnover of collagen based on the amount of these substances in the arterial wall which interact with each other to modify the turnover rate of collagen. We simulate this process in a finite element model of a real human carotid artery. The final results show the well-known stiffening of the arterial wall due to the increase in the collagen content.

  6. Study of the role and distribution of wall shear stress in rabbit atherosclerotic carotid artery%家兔颈动脉粥样硬化壁面剪应力分布及作用的探讨

    Institute of Scientific and Technical Information of China (English)

    黄志芳; 陈明; 张宇辉; 夏良华; 曲俊朴; 王超; 涂志兰; 黄东雅

    2014-01-01

    目的 探讨家兔颈总动脉粥样硬化(AS)发病过程中动脉血管壁上壁面剪应力(WSS)的分布及其对AS进程的影响.方法 24只新西兰大白兔随机分为对照组(正常饲料喂养,12只)和实验组(采用空气干燥加高脂饮食制造AS模型,12只).空气干燥术后2、4、8、12周采用彩色多普勒超声及血流剪应力定量分析软件测定血流动力学参数,分别于术后第4、8、12周处死实验组兔4只,处死前检测血脂,并做病理切片观察颈动脉病变的形态特征,对照组兔在第4周全部处死,获得相应的数据,进行对照分析.结果 实验组的各项血脂指标呈不同程度的升高,与对照组比较差异具有统计学意义(P<0.01).实验组从实施手术开始至术后4周,颈总动脉低WSS数目的分布增加,实验组左侧颈总动脉内约45%的WSS集中在0.2~0.4 N/m2,右侧约36%,左侧颈总动脉WSS降低的速度比右侧进展快.至术后8~12周,实验组颈总动脉低WSS分布反而减少,而高WSS血流点数目增加,实施干燥术后12周,实验组颈总动脉管壁逐渐僵硬、增厚,脂质沉积增加,平滑肌移行增殖,胶原增生,弹性降低,实验组左侧颈总动脉AS程度重于右侧.各项实验结果均证实实验组出现较典型的AS改变.结论 随着AS进程的延长,实验兔颈总动脉局部WSS逐步降低,低WSS进一步刺激血管内皮细胞增生,出现颈总动脉内中膜增厚及血管重构,提示颈总动脉WSS减低与动脉AS的形成有关.%Objective To dynamically observe the distribution of wall shear stress (WSS) in the carotid artery of rabbit and its impact on atherosclerosis(AS) by using AS model.Methods Twenty-four New Zealand white rabbits were randomly divided into control group (normal diet,n =12) and experimental group (air-drying plus high fat diet,n =12).In the 2nd,4th,8th,12th week after operation,hemodynamic parameters were measured by using color Doppler flow imaging and shear stress

  7. Nuclear IL-33 regulates soluble ST2 receptor and IL-6 expression in primary human arterial endothelial cells and is decreased in idiopathic pulmonary arterial hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Dongmin [Section of Vascular Biology, National Heart and Lung Institute, Imperial College London, London (United Kingdom); Perros, Frédéric [Faculté de Médecine, Université Paris-Sud, Paris, Clamart (France); Caramori, Gaetano [Dipartimento di Scienze Mediche, Sezione di Medicina Interna e Cardiorespiratoria, Centro Interdipartimentale per lo Studio delle Malattie Infiammatorie delle Vie Aeree e Patologie Fumo-Correlate, University of Ferrara, Ferrara (Italy); Meng, Chao [Section of Vascular Biology, National Heart and Lung Institute, Imperial College London, London (United Kingdom); Department of Geriatrics, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai (China); Dormuller, Peter [Faculté de Médecine, Université Paris-Sud, Paris, Clamart (France); Chou, Pai-Chien [Airways Disease, National Heart and Lung Institute (United Kingdom); Church, Colin [Scottish Pulmonary Vascular Unit, University of Glasgow (United Kingdom); Papi, Alberto; Casolari, Paolo [Dipartimento di Scienze Mediche, Sezione di Medicina Interna e Cardiorespiratoria, Centro Interdipartimentale per lo Studio delle Malattie Infiammatorie delle Vie Aeree e Patologie Fumo-Correlate, University of Ferrara, Ferrara (Italy); Welsh, David; Peacock, Andrew [Scottish Pulmonary Vascular Unit, University of Glasgow (United Kingdom); Humbert, Marc [Faculté de Médecine, Université Paris-Sud, Paris, Clamart (France); Adcock, Ian M. [Airways Disease, National Heart and Lung Institute (United Kingdom); Wort, Stephen J., E-mail: s.wort@imperial.ac.uk [Section of Vascular Biology, National Heart and Lung Institute, Imperial College London, London (United Kingdom)

    2014-08-15

    Highlights: • Nuclear IL-33 expression is reduced in vascular endothelial cells from PAH patients. • Knockdown of IL-33 leads to increased IL-6 and sST2 mRNA expression. • IL-33 binds homeobox motifs in target gene promoters and recruits repressor proteins. - Abstract: Idiopathic pulmonary arterial hypertension (IPAH) is an incurable condition leading to right ventricular failure and death and inflammation is postulated to be associated with vascular remodelling. Interleukin (IL)-33, a member of the “alarmin” family can either act on the membrane ST2 receptor or as a nuclear repressor, to regulate inflammation. We show, using immunohistochemistry, that IL-33 expression is nuclear in the vessels of healthy subjects whereas nuclear IL-33 is markedly diminished in the vessels of IPAH patients. This correlates with reduced IL-33 mRNA expression in their lung. In contrast, serum levels of IL-33 are unchanged in IPAH. However, the expression of the soluble form of ST2, sST2, is enhanced in the serum of IPAH patients. Knock-down of IL-33 in human endothelial cells (ECs) using siRNA is associated with selective modulation of inflammatory genes involved in vascular remodelling including IL-6. Additionally, IL-33 knock-down significantly increased sST2 release from ECs. Chromatin immunoprecipitation demonstrated that IL-33 bound multiple putative homeodomain protein binding motifs in the proximal and distal promoters of ST2 genes. IL-33 formed a complex with the histone methyltransferase SUV39H1, a transcriptional repressor. In conclusion, IL-33 regulates the expression of IL-6 and sST2, an endogenous IL-33 inhibitor, in primary human ECs and may play an important role in the pathogenesis of PAH through recruitment of transcriptional repressor proteins.

  8. Increased chemosensitivity and radiosensitivity of human breast cancer cell lines treated with novel functionalized single-walled carbon nanotubes

    Science.gov (United States)

    Jia, Yijun; Weng, Ziyi; Wang, Chuanying; Zhu, Mingjie; Lu, Yunshu; Ding, Longlong; Wang, Yongkun; Cheng, Xianhua; Lin, Qing; Wu, Kejin

    2017-01-01

    Hypoxia is a major cause of treatment resistance in breast cancer. Single-walled carbon nanotubes (SWCNTs) exhibit unique properties that make them promising candidates for breast cancer treatment. In the present study, a new functionalized single-walled carbon nanotube carrying oxygen was synthesized; it was determined whether this material could increase chemosensitivity and radiosensitivity of human breast cancer cell lines, and the underlying mechanisms were investigated. MDA-MB-231 cells growing in folic acid (FA) free medium, MDA-MB-231 cells growing in medium containing FA and ZR-75-1 cells were treated with chemotherapy drugs or radiotherapy with or without tombarthite-modified-FA-chitosan (R-O2-FA-CHI)-SWCNTs under hypoxic conditions, and the cell viability was determined by water-soluble tetrazolium salts-1 assay. The cell surviving fractions were determined by colony forming assay. Cell apoptosis induction was monitored by flow cytometry. Expression of B-cell lymphoma 2 (Bcl-2), survivin, hypoxia-inducible factor 1-α (HIF-1α), multidrug resistance-associated protein 1 (MRP-1), P-glycoprotein (P-gp), RAD51 and Ku80 was monitored by western blotting. The novel synthesized R-O2-FA-CHI-SWCNTs were able to significantly enhance the chemosensitivity and radiosensitivity of human breast cancer cell lines and the material exhibited its expected function by downregulating the expression of Bcl-2, survivin, HIF-1α, P-gp, MRP-1, RAD51 and Ku80.

  9. Human antimicrobial peptide LL-37 inhibits adhesion of Candida albicans by interacting with yeast cell-wall ca