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Sample records for blood vessel growth

  1. Blood vessel growth blocker may treat AIDS-related Kaposi’s sarcoma

    Science.gov (United States)

    Patients with an AIDS-associated cancer, Kaposi's sarcoma (KS), showed improvement after receiving the combination of bevacizumab, a cancer drug that blocks the growth of new blood vessels, and highly active antiretroviral therapy (HAART).

  2. Growth and Remodeling in Blood Vessels Studied In Vivo With Fractal Analysis

    Science.gov (United States)

    Parsons-Wingerter, Patricia A.

    2003-01-01

    Every cell in the human body must reside in close proximity to a blood vessel (within approximately 200 mm) because blood vessels provide the oxygen, metabolite, and fluid exchanges required for cellular existence. The growth and remodeling of blood vessels are required to support the normal physiology of embryonic development, reproductive biology, wound healing and adaptive remodeling to exercise, as well as abnormal tissue change in diseases such as cancer, diabetes, and coronary heart disease. Cardiovascular and hemodynamic (blood flow dynamics) alterations experienced by astronauts during long-term spaceflight, including orthostatic intolerance, fluid shifts in the body, and reduced numbers of red (erythrocyte) and white (immune) blood cells, are identified as risk factors of very high priority in the NASA task force report on risk reduction for human spaceflight, the "Critical Path Roadmap."

  3. Contact-inhibited chemotaxis in de novo and sprouting blood-vessel growth.

    Directory of Open Access Journals (Sweden)

    Roeland M H Merks

    Full Text Available Blood vessels form either when dispersed endothelial cells (the cells lining the inner walls of fully formed blood vessels organize into a vessel network (vasculogenesis, or by sprouting or splitting of existing blood vessels (angiogenesis. Although they are closely related biologically, no current model explains both phenomena with a single biophysical mechanism. Most computational models describe sprouting at the level of the blood vessel, ignoring how cell behavior drives branch splitting during sprouting. We present a cell-based, Glazier-Graner-Hogeweg model (also called Cellular Potts Model simulation of the initial patterning before the vascular cords form lumens, based on plausible behaviors of endothelial cells. The endothelial cells secrete a chemoattractant, which attracts other endothelial cells. As in the classic Keller-Segel model, chemotaxis by itself causes cells to aggregate into isolated clusters. However, including experimentally observed VE-cadherin-mediated contact inhibition of chemotaxis in the simulation causes randomly distributed cells to organize into networks and cell aggregates to sprout, reproducing aspects of both de novo and sprouting blood-vessel growth. We discuss two branching instabilities responsible for our results. Cells at the surfaces of cell clusters attempting to migrate to the centers of the clusters produce a buckling instability. In a model variant that eliminates the surface-normal force, a dissipative mechanism drives sprouting, with the secreted chemical acting both as a chemoattractant and as an inhibitor of pseudopod extension. Both mechanisms would also apply if force transmission through the extracellular matrix rather than chemical signaling mediated cell-cell interactions. The branching instabilities responsible for our results, which result from contact inhibition of chemotaxis, are both generic developmental mechanisms and interesting examples of unusual patterning instabilities.

  4. Examining blood vessels

    International Nuclear Information System (INIS)

    This patent specification relates to an invention concerned with improvements in or relating to the examination of blood vessels of interest. Particles of dimensions not greater than 8 microns capable of providing detectable signals, are introduced into the blood for examination of a blood vessel. The particles may be sources of radiation, e.g. Ga68. (author)

  5. Tumor Blood Vessel Dynamics

    Science.gov (United States)

    Munn, Lance

    2009-11-01

    ``Normalization'' of tumor blood vessels has shown promise to improve the efficacy of chemotherapeutics. In theory, anti-angiogenic drugs targeting endothelial VEGF signaling can improve vessel network structure and function, enhancing the transport of subsequent cytotoxic drugs to cancer cells. In practice, the effects are unpredictable, with varying levels of success. The predominant effects of anti-VEGF therapies are decreased vessel leakiness (hydraulic conductivity), decreased vessel diameters and pruning of the immature vessel network. It is thought that each of these can influence perfusion of the vessel network, inducing flow in regions that were previously sluggish or stagnant. Unfortunately, when anti-VEGF therapies affect vessel structure and function, the changes are dynamic and overlapping in time, and it has been difficult to identify a consistent and predictable normalization ``window'' during which perfusion and subsequent drug delivery is optimal. This is largely due to the non-linearity in the system, and the inability to distinguish the effects of decreased vessel leakiness from those due to network structural changes in clinical trials or animal studies. We have developed a mathematical model to calculate blood flow in complex tumor networks imaged by two-photon microscopy. The model incorporates the necessary and sufficient components for addressing the problem of normalization of tumor vasculature: i) lattice-Boltzmann calculations of the full flow field within the vasculature and within the tissue, ii) diffusion and convection of soluble species such as oxygen or drugs within vessels and the tissue domain, iii) distinct and spatially-resolved vessel hydraulic conductivities and permeabilities for each species, iv) erythrocyte particles advecting in the flow and delivering oxygen with real oxygen release kinetics, v) shear stress-mediated vascular remodeling. This model, guided by multi-parameter intravital imaging of tumor vessel structure

  6. Hypoxia-inducible factor and vascular endothelial growth factor in the neuroretina and retinal blood vessels after retinal ischemia

    DEFF Research Database (Denmark)

    Håkansson, Gisela; Gesslein, Bodil; Gustafsson, Lotta;

    2010-01-01

    Retinal ischemia arises from circulatory failure. As the retinal blood vessels are key organs in circulatory failure, our aim was to study the retinal vasculature separately from the neuroretina to elucidate the role of hypoxia-inducible factor (HIF) 1α and 1β and vascular endothelial growth factor...... (VEGF) in retinal ischemia. Retinal ischemia was induced in porcine eyes by applying an intraocular pressure, followed by 12 h of reperfusion. HIF-1α mRNA expression was not affected by ischemia, while immunofluorescence staining was higher after ischemia in the neuroretina. HIF-1β immunoreactivity and...

  7. 基于DLA模型的人体血管生长模拟方法%Simulation Method of Human Blood Vessel Growth Based on DLA Model

    Institute of Scientific and Technical Information of China (English)

    王素; 吴梦天; 张珣; 夏斌; 徐亮

    2016-01-01

    Currently the generating methods of blood vessel structure are from the trunk to the branch, which is incompatible with the blood vessels growth in natural state and leads to some differences in the construction of human blood vessel model. This paper proposes a fractal algorithm for simulation of human blood vessel growth, namely diffusion-limited aggregation model (DLA) based simulation of human blood vessel growth. Firstly, combining fractal algorithm with constrained optimization, the paper establishes a natural growth method of blood vessel curves with directed motion and Brownian motion; and then generates blood vessel curve structure by using the deterministic zero-sided L system (D0L), simulates, in the manner from branch to trunk, the fractal graphics condensed mostly in the natural state, which makes the generated blood vessel model more realistic in structure compared with the blood vessel in natural growth. The experiment and analysis with simulated blood vessel growth show that the algorithm is feasible and the precision is guaranteed.%针对现有研究血管曲线结构生成方法均是从主干到支干的形式,与血管自然生长不符,导致构建的人体血管模型与实际生长结构存在一定差异的局限性的问题,提出一种模拟人体血管生长的分形算法,即基于受限扩散凝聚(DLA)模型的人体血管生长模拟算法.首先结合分形算法与约束构建优化方法的特点,建立兼具布朗运动与定向运动的血管曲线自然生长方法;然后运用分形算法中的确定型林氏无关系统(D0L)生成血管曲线结构,以支干生成主干的方式模拟大量自然状态下凝聚而成的分形图形,使构建的血管模型逼真自然血管的生长结构特性.对模拟血管的生长实验与分析结果表明,该算法具有可行性且精度得到保证.

  8. Blood vessel rupture by cavitation

    OpenAIRE

    Chen, Hong; Brayman, Andrew A.; Bailey, Michael R.; Matula, Thomas J.

    2010-01-01

    Cavitation is thought to be one mechanism for vessel rupture during shock wave lithotripsy treatment. However, just how cavitation induces vessel rupture remains unknown. In this work, a high-speed photomicrography system was set up to directly observe the dynamics of bubbles inside blood vessels in ex vivo rat mesenteries. Vascular rupture correlating to observed bubble dynamics were examined by imaging bubble extravasation and dye leakage. The high-speed images show that bubble expansion ca...

  9. [Pulmonary blood vessels in goats].

    Science.gov (United States)

    Roos, H; Hegner, K; Vollmerhaus, B

    1999-05-01

    The blood vessels in the lung of the goat, which until now have received little attention, are described in detail for the first time. With regard to the segments of the lung, blood vessels are bronchovascular units in the lobi craniales, lobus medius and lobus accessorius, but bronchoartery units in the lobi caudales. We investigated the types of branches of the Aa. pulmonales dextra et sinistra, the inter- and intraspecific principles of the outlet of the pulmonary veins and the importance of bronchopulmonary segmentation of the lungs. PMID:10386009

  10. Angiogenesis & Vasculogenesis: Inducing the growth of new blood vessels and wound healing by stimulation of Bone Marrow Derived Progenitor Cell Mobilization and Homing

    Science.gov (United States)

    Velazquez, Omaida C.

    2009-01-01

    During embryonic development, the vasculature is among the first organs to form and is in charge of maintaining metabolic homeostasis by supplying oxygen and nutrients and removing waste products. As one would expect, blood vessels are critical not only for organ growth in the embryo, but also for repair of wounded tissue in the adult. An imbalance in ‘Angiogenesis’ (a time-honored term that globally refers to the growth of new blood vessels) contributes to the pathogenesis of numerous malignant, inflammatory, ischemic, infectious, immune, and wound healing disorders. In this review, we will focus on the central role of the growth of new blood vessels in ischemic and diabetic wound healing. We define the most current nomenclature that describes the neovascularization process in wounds. There are now two well defined, distinct, yet interrelated processes for the formation of post-natal new blood vessels, angiogenesis and vasculogenesis. We review recent new data on vasculogenesis that promises to advance the field of wound healing. PMID:17544023

  11. Mathematical Modelling of a Brain Tumour Initiation and Early Development: A Coupled Model of Glioblastoma Growth, Pre-Existing Vessel Co-Option, Angiogenesis and Blood Perfusion

    Science.gov (United States)

    Cai, Yan; Wu, Jie; Li, Zhiyong; Long, Quan

    2016-01-01

    We propose a coupled mathematical modelling system to investigate glioblastoma growth in response to dynamic changes in chemical and haemodynamic microenvironments caused by pre-existing vessel co-option, remodelling, collapse and angiogenesis. A typical tree-like architecture network with different orders for vessel diameter is designed to model pre-existing vasculature in host tissue. The chemical substances including oxygen, vascular endothelial growth factor, extra-cellular matrix and matrix degradation enzymes are calculated based on the haemodynamic environment which is obtained by coupled modelling of intravascular blood flow with interstitial fluid flow. The haemodynamic changes, including vessel diameter and permeability, are introduced to reflect a series of pathological characteristics of abnormal tumour vessels including vessel dilation, leakage, angiogenesis, regression and collapse. Migrating cells are included as a new phenotype to describe the migration behaviour of malignant tumour cells. The simulation focuses on the avascular phase of tumour development and stops at an early phase of angiogenesis. The model is able to demonstrate the main features of glioblastoma growth in this phase such as the formation of pseudopalisades, cell migration along the host vessels, the pre-existing vasculature co-option, angiogenesis and remodelling. The model also enables us to examine the influence of initial conditions and local environment on the early phase of glioblastoma growth. PMID:26934465

  12. Tea May Benefit Blood Vessels

    Institute of Scientific and Technical Information of China (English)

    华剑铭

    2000-01-01

    读到有关饮茶有益健康的消息,我总是充满了自豪感:茶的故乡毕竟在中国。饮茶对人的心脏有益,这已经不是新闻,但是到底如何起到此类保健作用,多年来一直是一个谜。本文揭开了此谜底: Drinking a cup of tea makes blood vessels work better within 2 hours, dilating(扩张)the arteries(动脉)and improving blood flow. 文章令我感动之处在于那些科研人员的敬业精神。比如茶中含有caffeine(咖啡因),饮茶对心脏有利,此“利”是否源于caffeine呢?试验人员为了弄清这 一点,便让另一组受试人员服用等量的caffeine,结果证实:Caffeine had no response on the blood vessel function.】

  13. Zinc oxide nanoflowers make new blood vessels

    Science.gov (United States)

    Barui, Ayan Kumar; Veeriah, Vimal; Mukherjee, Sudip; Manna, Joydeb; Patel, Ajay Kumar; Patra, Sujata; Pal, Krishnendu; Murali, Shruthi; Rana, Rohit K.; Chatterjee, Suvro; Patra, Chitta Ranjan

    2012-11-01

    It is well established that angiogenesis is the process of formation of new capillaries from pre-existing blood vessels. It is a complex process, involving both pro- and anti-angiogenic factors, and plays a significant role in physiological and pathophysiological processes such as embryonic development, atherosclerosis, post-ischemic vascularization of the myocardium, tumor growth and metastasis, rheumatoid arthritis etc. This is the first report of zinc oxide (ZnO) nanoflowers that show significant pro-angiogenic properties (formation of new capillaries from pre-existing blood vessels), observed by in vitro and in vivo angiogenesis assays. The egg yolk angiogenesis assay using ZnO nanoflowers indicates the presence of matured blood vessels formation. Additionally, it helps to promote endothelial cell (EA.hy926 cells) migration in wound healing assays. Formation of reactive oxygen species (ROS), especially hydrogen peroxide (H2O2)--a redox signaling molecule, might be the plausible mechanism for nanoflower-based angiogenesis. Angiogenesis by nanoflowers may provide the basis for the future development of new alternative therapeutic treatment strategies for cardiovascular and ischemic diseases, where angiogenesis plays a significant role.It is well established that angiogenesis is the process of formation of new capillaries from pre-existing blood vessels. It is a complex process, involving both pro- and anti-angiogenic factors, and plays a significant role in physiological and pathophysiological processes such as embryonic development, atherosclerosis, post-ischemic vascularization of the myocardium, tumor growth and metastasis, rheumatoid arthritis etc. This is the first report of zinc oxide (ZnO) nanoflowers that show significant pro-angiogenic properties (formation of new capillaries from pre-existing blood vessels), observed by in vitro and in vivo angiogenesis assays. The egg yolk angiogenesis assay using ZnO nanoflowers indicates the presence of matured blood

  14. Photoacoustic determination of blood vessel diameter

    Science.gov (United States)

    Kolkman, Roy G. M.; Klaessens, John H. G. M.; Hondebrink, Erwin; Hopman, Jeroen C. W.; de Mul, Frits F. M.; Steenbergen, Wiendelt; Thijssen, Johan M.; van Leeuwen, Ton G.

    2004-10-01

    A double-ring sensor was applied in photoacoustic tomographic imaging of artificial blood vessels as well as blood vessels in a rabbit ear. The peak-to-peak time (tgrpp) of the laser (1064 nm) induced pressure transient was used to estimate the axial vessel diameter. Comparison with the actual vessel diameter showed that the diameter could be approximated by 2ctgrpp, with c the speed of sound in blood. Using this relation, the lateral diameter could also precisely be determined. In vivo imaging and monitoring of changes in vessel diameters was feasible. Finally, acoustic time traces were recorded while flushing a vessel in the rabbit ear with saline, which proved that the main contribution to the laser-induced pressure transient is caused by blood inside the vessel and that the vessel wall gives only a minor contribution.

  15. Photoacoustic determination of blood vessel diameter

    International Nuclear Information System (INIS)

    A double-ring sensor was applied in photoacoustic tomographic imaging of artificial blood vessels as well as blood vessels in a rabbit ear. The peak-to-peak time (τpp) of the laser (1064 nm) induced pressure transient was used to estimate the axial vessel diameter. Comparison with the actual vessel diameter showed that the diameter could be approximated by 2cτpp, with c the speed of sound in blood. Using this relation, the lateral diameter could also precisely be determined. In vivo imaging and monitoring of changes in vessel diameters was feasible. Finally, acoustic time traces were recorded while flushing a vessel in the rabbit ear with saline, which proved that the main contribution to the laser-induced pressure transient is caused by blood inside the vessel and that the vessel wall gives only a minor contribution

  16. Strain Growth in Containment Vessels

    Institute of Scientific and Technical Information of China (English)

    DONG Q; LI Q M; ZHENG J Y

    2006-01-01

    Strain growth is a phenomenon observed in containment vessels subjected to internal blast loading.The elastic response of the vessel may become larger in a later stage compared to its response during the initial stage.The dynamic responses of infinitely long cylindrical containment vessels subjected to uniformly-distributed internal blast loading are studied using LS-DYNA.The development of bending modes and the interaction between the breathing mode and bending modes are observed.The methodology developed for dynamic elastic buckling analysis is employed to study the strain growth phenomenon in explosion containment vessels.It is shown that the dynamic instable vibration of a containment vessel is the basic mechanism of strain growth.

  17. Complete Blood Count and Retinal Vessel Calibers

    OpenAIRE

    Liew, Gerald; Wang, Jie Jin; Rochtchina, Elena; Wong, Tien Yin; Mitchell, Paul

    2014-01-01

    Objective The influence of hematological indices such as complete blood count on microcirculation is poorly understood. Retinal microvasculature can be directly visualized and vessel calibers are associated with a range of ocular and systemic diseases. We examined the association of complete blood count with retinal vessel calibers. Methods Cross-sectional population-based Blue Mountains Eye Study, n = 3009, aged 49+ years. Complete blood count was measured from fasting blood samples taken at...

  18. Morphometric evaluation of endometrial blood vessels

    Directory of Open Access Journals (Sweden)

    Makhija Divya

    2008-07-01

    Full Text Available Five hundred endometrial specimens were studied to document the changes in blood vessels in various phases of menstrual cycle, menstrual disturbances and in unexplained infertility. Sixty-three cases were taken as control and 437 cases as study group which included cases of dysfunctional uterine bleeding (DUB, endometrial polyps, fibroids, adenomyosis, infertility and atrophic endometrium. Using light microscopy, the vascular morphology was studied. The blood vessels were concentrated more in basal layer in the proliferative phase and in functional layer in the secretory phase. Cases of complex hyperplasia and pill endometrium had significantly higher vessel concentration. Congestion and dilatation of blood vessels were significantly higher in cases of DUB. The present study showed a positive correlation between endometrial angiogenesis and menstrual disorders. The alteration in blood vessel morphology has significant role in prognosis and in various anti-angiogenic therapies.

  19. Classification & Structure of Blood Vessels

    Science.gov (United States)

    ... Thyroid & Parathyroid Glands Adrenal Gland Pancreas Gonads Other Endocrine Glands Review Quiz Cardiovascular System Heart Structure of the Heart Physiology of the Heart Blood Classification & Structure of Blood ...

  20. BLOOD VESSELS EXTRACTION USING MATHEMATICAL MORPHOLOGY

    Directory of Open Access Journals (Sweden)

    Nidhal Khdhair El Abbadi

    2013-01-01

    Full Text Available The retinal vasculature is composed of the arteries and veins with their tributaries which are visible within the retinal image. The segmentation and measurement of the retinal vasculature is of primary interest in the diagnosis and treatment of a number of systemic and ophthalmologic conditions. The accurate segmentation of the retinal blood vessels is often an essential prerequisite step in the identification of retinal anatomy and pathology. In this study, we present an automated approach for blood vessels extraction using mathematical morphology. Two main steps are involved: enhancement operation is applied to the original retinal image in order to remove the noise and increase contrast of retinal blood vessels and morphology operations are employed to extract retinal blood vessels. This operation of segmentation is applied to binary image of top-hat transformation. The result was compared with other algorithms and give better results.

  1. Videodensitometry for measuring blood vessel diameter

    International Nuclear Information System (INIS)

    A method employing a special computer for determining the internal diameters of blood vessels from photofluorographic image is described; in vitro and in vivo experiments are performed with the system. The amount of contrast medium injected is restricted to 4x3 ml, and it is possible to determine the diameter (in the range from 2 to 16 mm) at any place where blood vessels can be catheterized. In the in vivo experiments the maximum systematic error is +-5 per cent in the 7 to 8 mm range. (Auth.)

  2. Videodensitometry for measuring blood vessel diameter.

    Science.gov (United States)

    Hoornstra, K; Hanselman, J M; Holland, W P; De Wey Peters, G W; Zwamborn, A W

    1980-01-01

    A method employing a special computer for determining the internal diameters of blood vessels from photofluorographic image is described; in vitro and in vivo experiments are performed with the system. The amount of contrast medium injected is restricted to 4 times 3 ml, and it is possible to determine the diameter (in the range from 2 to 16 mm) at any place where blood vessels can be catheterized. In the in vivo experiments the maximum systematic error is +/-5 percent in the 7 to 8 mm range. PMID:7424549

  3. Complete blood count and retinal vessel calibers.

    Directory of Open Access Journals (Sweden)

    Gerald Liew

    Full Text Available OBJECTIVE: The influence of hematological indices such as complete blood count on microcirculation is poorly understood. Retinal microvasculature can be directly visualized and vessel calibers are associated with a range of ocular and systemic diseases. We examined the association of complete blood count with retinal vessel calibers. METHODS: Cross-sectional population-based Blue Mountains Eye Study, n = 3009, aged 49+ years. Complete blood count was measured from fasting blood samples taken at baseline examination, 1992-4. Retinal arteriolar and venular calibers were measured from digitized retinal photographs using a validated semi-automated computer program. RESULTS: All analyses adjusted for age, sex, systolic blood pressure, diabetes, smoking and fellow vessel caliber. Higher hematocrit, white cell count and platelet count were associated with narrower arteriolar caliber (p = 0.02, 0.03 and 0.001 respectively, while higher hemoglobin, hematocrit, red cell count, white cell count and platelet count were associated with wider venular caliber (p<0.0001 for all. Each quintile increase in hematocrit, white cell count and platelet count was associated with approximately 0.5 µm narrower arteriolar caliber; whereas each quintile increase in all of the complete blood count components was associated with approximately 1-2 µm wider venular caliber. CONCLUSIONS: These associations show that elevated levels of hematological indices can have adverse effects on the microcirculation.

  4. Preventing pathological regression of blood vessels

    OpenAIRE

    Keshet, Eli

    2003-01-01

    Oxygen administration to premature infants suppresses retinal VEGF expression and results in the catastrophic vessel loss associated with retinopathy of prematurity. A study investigating the development of the retinal vasculature in mice (see related article on pages 50–57) demonstrates that specific activation of VEGF receptor-1 by placental growth factor-1 protects against oxygen-induced vessel loss without stimulating vascular proliferation and neovascularization.

  5. By Different Cellular Mechanisms, Lymphatic Vessels Sprout by Endothelial Cell Recruitment Whereas Blood Vessels Grow by Vascular Expansion

    Science.gov (United States)

    Parsons-Wingerter, Patricia; McKay, Terri L.; Leontiev, Dmitry; Condrich, Terence K.; DiCorleto, Paul E.

    2005-01-01

    The development of effective vascular therapies requires the understanding of all modes of vessel formation contributing to vasculogenesis, angiogenesis (here termed hemangiogenesis) and lymphangiogenesis. We show that lymphangiogenesis proceeds by blind-ended vessel sprouting via recruitment of isolated endothelial progenitor cells to the tips of growing vessels, whereas hemangiogenesis occurs by non-sprouting vessel expansion from the capillary network, during middevelopment in the quail chorioallantoic membrane (CAM). Blood vessels expanded out of capillaries that displayed transient expression of alpha smooth muscle actin (alphaSMA), accompanied by mural recruitment of migratory progenitor cells expressing SMA. Lymphatics and blood vessels were identified by confocal/fluorescence microscopy of vascular endothelial growth factor (VEGF) receptors VEGFR-1 and VEGFR-2, alphaSMA (expressed on CAM blood vessels but not on lymphatics), homeobox transcription factor Prox-1 (specific to CAM lymphatic endothelium), and the quail hematopoetic/vascular marker, QH-1. Expression of VEGFR-1 was highly restricted to blood vessels (primarily capillaries). VEGFR-2 was expressed intensely in isolated hematopoietic cells, lymphatic vessels and moderately in blood vessels. Prox-1 was absent from endothelial progenitor cells prior to lymphatic recruitment. Although vascular endothelial growth factor-165 (VEGF(sub 165)) is a key regulator of numerous cellular processes in hemangiogenesis and vasculogenesis, the role of VEGF(sub 165) in lymphangiogenesis is less clear. Exogenous VEGF(sub 165) increased blood vessel density without changing endogenous modes of vascular/lymphatic vessel formation or marker expression patterns. However, VEGF(sub 165) did increase the frequency of blood vascular anastomoses and strongly induced the antimaturational dissociation of lymphatics from blood vessels, with frequent formation of homogeneous lymphatic networks.

  6. Automated measurement of retinal blood vessel tortuosity

    Science.gov (United States)

    Joshi, Vinayak; Reinhardt, Joseph M.; Abramoff, Michael D.

    2010-03-01

    Abnormalities in the vascular pattern of the retina are associated with retinal diseases and are also risk factors for systemic diseases, especially cardiovascular diseases. The three-dimensional retinal vascular pattern is mostly formed congenitally, but is then modified over life, in response to aging, vessel wall dystrophies and long term changes in blood flow and pressure. A characteristic of the vascular pattern that is appreciated by clinicians is vascular tortuosity, i.e. how curved or kinked a blood vessel, either vein or artery, appears along its course. We developed a new quantitative metric for vascular tortuosity, based on the vessel's angle of curvature, length of the curved vessel over its chord length (arc to chord ratio), number of curvature sign changes, and combined these into a unidimensional metric, Tortuosity Index (TI). In comparison to other published methods this method can estimate appropriate TI for vessels with constant curvature sign and vessels with equal arc to chord ratios, as well. We applied this method to a dataset of 15 digital fundus images of 8 patients with Facioscapulohumeral muscular dystrophy (FSHD), and to the other publically available dataset of 60 fundus images of normal cases and patients with hypertensive retinopathy, of which the arterial and venous tortuosities have also been graded by masked experts (ophthalmologists). The method produced exactly the same rank-ordered list of vessel tortuosity (TI) values as obtained by averaging the tortuosity grading given by 3 ophthalmologists for FSHD dataset and a list of TI values with high ranking correlation with the ophthalmologist's grading for the other dataset. Our results show that TI has potential to detect and evaluate abnormal retinal vascular structure in early diagnosis and prognosis of retinopathies.

  7. A Functional Requirement for Astroglia in Promoting Blood Vessel Development in the Early Postnatal Brain

    OpenAIRE

    Shang Ma; Hyo Jun Kwon; Zhen Huang

    2012-01-01

    Astroglia are a major cell type in the brain and play a key role in many aspects of brain development and function. In the adult brain, astrocytes are known to intimately ensheath blood vessels and actively coordinate local neural activity and blood flow. During development of the neural retina, blood vessel growth follows a meshwork of astrocytic processes. Several genes have also been implicated in retinal astrocytes for regulating vessel development. This suggests a role of astrocytes in p...

  8. Endothelium-dependent relaxation of blood vessels

    International Nuclear Information System (INIS)

    Dilation of blood vessels in response to a large number of agents has been shown to be dependent on an intact vascular endothelium. The present studies examine some aspects of endothelium-dependent vasodilation in blood vessels of the rabbit and rat. Using the rabbit ear artery and the subtype-selective muscarinic antagonist pirenzepine, muscarinic receptors of the endothelium and smooth muscle cells were shown to be of the low affinity M2 subtype. Inhibition of [3H](-)quinuclidinyl benzilate was used to determine affinity for the smooth muscle receptors while antagonism of methacholine induced vasodilation yielded the endothelial cell receptor affinity. The effect of increasing age (1-27 months) on endothelium-dependent relaxation was studied in aortic rings, perfused tail artery and perfused mesenteric bed of the Fisher 344 rat. The influence of endothelium on contractile responses was examined using the perfused caudal artery

  9. Noninvasive blood pressure measurement in large vessels

    International Nuclear Information System (INIS)

    Pulse pressure in the aorta was evaluated by the measurement of pulse wave velocity (PWV) and blood flow velocity (BFV). PWV reflects the elasticity of the vessel and was determined by a time-of-flight method. BFV was measured by analyzing the change of magnetization decay due to flow in multiecho experiments. If one neglects pulse wave reflections at vascular branch points and flow resistance due to blood viscosity, pulse pressure is proportional to PWV and BFV. Noninvasive MR imaging measurements were obtained in 12 patients, all of whom underwent correlative arterial catheterization. Values varied between 35 and 100 mm Hg. The results demonstrated a high correlation between the two methods

  10. Water hammer experiment in artificial blood vessel

    Czech Academy of Sciences Publication Activity Database

    Hromádka, D.; Horný, L.; Žitný, R.; Chlup, Hynek

    Liberec : Technical University of Liberec, 2010 - (Čapek, L.), s. 127-132 ISBN 978-80-7372-648-5. [Human Biomechanics 2010. Sychrov (CZ), 04.10.2010-06.10.2010] R&D Projects: GA ČR(CZ) GA106/08/0557 Institutional research plan: CEZ:AV0Z20760514 Keywords : water hammer * artificial blood vessel * reinforced latex tube Subject RIV: JJ - Other Materials

  11. Designer blood vessels and therapeutic revascularization

    OpenAIRE

    Berglund, Joseph D; Galis, Zorina S.

    2003-01-01

    Inadequate vascular perfusion leads to fatal heart attacks, chronic ulcers, and other serious clinical conditions. The body's capacity to restore vascular perfusion through angiogenesis and arteriogenesis is often impaired by pre-existing disease, and availability of native replacements for nonfunctional arteries is limited in many patients. Thus, recreating blood vessels of various calibres through novel engineering technologies has emerged as a radical option among therapeutic strategies fo...

  12. Gene expression analysis in human breast cancer associated blood vessels.

    Directory of Open Access Journals (Sweden)

    Dylan T Jones

    Full Text Available Angiogenesis is essential for solid tumour growth, whilst the molecular profiles of tumour blood vessels have been reported to be different between cancer types. Although presently available anti-angiogenic strategies are providing some promise for the treatment of some cancers it is perhaps not surprisingly that, none of the anti-angiogenic agents available work on all tumours. Thus, the discovery of novel anti-angiogenic targets, relevant to individual cancer types, is required. Using Affymetrix microarray analysis of laser-captured, CD31-positive blood vessels we have identified 63 genes that are upregulated significantly (5-72 fold in angiogenic blood vessels associated with human invasive ductal carcinoma (IDC of the breast as compared with blood vessels in normal human breast. We tested the angiogenic capacity of a subset of these genes. Genes were selected based on either their known cellular functions, their enriched expression in endothelial cells and/or their sensitivity to anti-VEGF treatment; all features implicating their involvement in angiogenesis. For example, RRM2, a ribonucleotide reductase involved in DNA synthesis, was upregulated 32-fold in IDC-associated blood vessels; ATF1, a nuclear activating transcription factor involved in cellular growth and survival was upregulated 23-fold in IDC-associated blood vessels and HEX-B, a hexosaminidase involved in the breakdown of GM2 gangliosides, was upregulated 8-fold in IDC-associated blood vessels. Furthermore, in silico analysis confirmed that AFT1 and HEX-B also were enriched in endothelial cells when compared with non-endothelial cells. None of these genes have been reported previously to be involved in neovascularisation. However, our data establish that siRNA depletion of Rrm2, Atf1 or Hex-B had significant anti-angiogenic effects in VEGF-stimulated ex vivo mouse aortic ring assays. Overall, our results provide proof-of-principle that our approach can identify a cohort of

  13. A Computational Model Predicting Disruption of Blood Vessel Development

    OpenAIRE

    Kleinstreuer, Nicole; Dix, David; Rountree, Michael; Baker, Nancy; Sipes, Nisha; Reif, David; Spencer, Richard; Knudsen, Thomas

    2013-01-01

    Vascular development is a complex process regulated by dynamic biological networks that vary in topology and state across different tissues and developmental stages. Signals regulating de novo blood vessel formation (vasculogenesis) and remodeling (angiogenesis) come from a variety of biological pathways linked to endothelial cell (EC) behavior, extracellular matrix (ECM) remodeling and the local generation of chemokines and growth factors. Simulating these interactions at a systems level req...

  14. Application of Computational Physics: Blood Vessel Constrictions and Medical Infuses

    CERN Document Server

    Suprijadi,; Subekti, Petrus; Viridi, Sparisoma

    2013-01-01

    Application of computation in many fields are growing fast in last two decades. Increasing on computation performance helps researchers to understand natural phenomena in many fields of science and technology including in life sciences. Computational fluid dynamic is one of numerical methods which is very popular used to describe those phenomena. In this paper we propose moving particle semi-implicit (MPS) and molecular dynamics (MD) to describe different phenomena in blood vessel. The effect of increasing the blood pressure on vessel wall will be calculate using MD methods, while the two fluid blending dynamics will be discussed using MPS. Result from the first phenomenon shows that around 80% of constriction on blood vessel make blood vessel increase and will start to leak on vessel wall, while from the second phenomenon the result shows the visualization of two fluids mixture (drugs and blood) influenced by ratio of drugs debit to blood debit. Keywords: molecular dynamic, blood vessel, fluid dynamic, movin...

  15. Morphogenetic mechanisms of blood vessel fusion in the Zebrafish embryo

    OpenAIRE

    Herwig, Lukas Walter

    2012-01-01

    The formation of a vascular network requires the connection and formation of a lumen between individual endothelial sprouts, a process called vessel fusion or anastomosis. In the vertebrate trunk of the zebrafish (Danio rerio), the intersegmental vessels (ISVs) develop by angiogenesis, i.e. the formation of new vessels by pre-existing vessels, in a conserved metameric manner, which allows the analysis of morphogenetic mechanisms of blood vessel development. From the dorsal aorta (DA) individu...

  16. Blood Vessel Diameter Estimation System Using Active Contours

    OpenAIRE

    Courtney, Jane; Tizon, Ana

    2011-01-01

    The study and analysis of blood vessel geometry has become the basis of medical applications related to early diagnosis and effective monitoring of therapies in vascular diseases. This paper presents a new method to trace the outline of blood vessels from imperfect images and extract useful information about their dimensions in an automated manner. The system consists of a segmentation procedure that uses two Active Contours to detect blood vessel boundaries and a novel approach to measure bl...

  17. Automated computational framework of blood vessel quantification in chick chorioallantoic membrane angiogenesis

    Science.gov (United States)

    Shi, Peng; Hong, Jinsheng; Huang, Yue; Zhang, Zhenhuan; Zhang, Mei; Zhang, Lurong

    2014-10-01

    Chick chorioallantoic membrane (CAM) angiogenesis assay has been widely used for finding drugs targeting new blood vessel development in cancer research. In addition to the setup materials and protocols, laboratory findings depend on the quantification and analysis of microscopic blood vessel images. However, it is still a challenging problem because of the high complexity of blood vessel branching structures. We applied preprocessing on CAM microscopic images by keeping the integrity of minor branches in the vessel structure. We then proposed an efficient way to automatically extract blood vessel centerlines based on vector tracing starting from detected seed points. Finally, all branches were coded to construct an abstract model of the branching structure, which enabled more accurate modeling for in-depth analysis. The framework was applied in quantifying Icaritin (ICT) inhibition effects on angiogenesis in a CAM model. Experimental results showed the high accuracy in blood vessel quantification and modeling compared with semimanual measurements. Meanwhile, a set of blood vessel growth indicators were extracted to provide fully automated analysis for angiogenesis assays. Further analysis proved that ICT took effect in a dose-dependent manner which could be applied in suppressing tumor blood vessel growth.

  18. Automated computational framework of blood vessel quantification in chick chorioallantoic membrane angiogenesis.

    Science.gov (United States)

    Shi, Peng; Hong, Jinsheng; Huang, Yue; Zhang, Zhenhuan; Zhang, Mei; Zhang, Lurong

    2014-01-01

    Chick chorioallantoic membrane (CAM) angiogenesis assay has been widely used for finding drugs targeting new blood vessel development in cancer research. In addition to the setup materials and protocols, laboratory findings depend on the quantification and analysis of microscopic blood vessel images. However, it is still a challenging problem because of the high complexity of blood vessel branching structures. We applied preprocessing on CAM microscopic images by keeping the integrity of minor branches in the vessel structure. We then proposed an efficient way to automatically extract blood vessel centerlines based on vector tracing starting from detected seed points. Finally, all branches were coded to construct an abstract model of the branching structure, which enabled more accurate modeling for in-depth analysis. The framework was applied in quantifying Icaritin (ICT) inhibition effects on angiogenesis in a CAM model. Experimental results showed the high accuracy in blood vessel quantification and modeling compared with semimanual measurements. Meanwhile, a set of blood vessel growth indicators were extracted to provide fully automated analysis for angiogenesis assays. Further analysis proved that ICT took effect in a dose-dependent manner which could be applied in suppressing tumor blood vessel growth. PMID:25277148

  19. Avian Blood-Vessel Formation in Space

    Science.gov (United States)

    Lelkes, Peter I.

    1999-01-01

    Based on previous studies, we hypothesized that the developmental anomalies observed in the past might be related to or caused by delayed or improper vascular development. The objective of our research is to test the hypothesis that exposure to microgravity during space flight cause delayed or improper vascular development during embryogenesis. The effects of microgravity on the time course and extent of avian blood-vessel formation are assessed using two models, one for angiogenesis and one for vasculogenesis. The methodological approach is dictated by the constraints of the tissue preservation method used in space. Thus, both in the chorioallantoic membrane (CAM) and in the adrenal, we will evaluate microscopically the vascular architecture and immunostain endothelial cells with specific antibodies (anti- vWF and QH1). The extent of ECM protein deposition will be assessed by immunohistochemistry and correlated with the degree of vascularization, using computer-based image analysis. Also, the cellular source for ECM proteins will be assessed by in situ hybridization.

  20. Tumour angiogenesis-Origin of blood vessels.

    Science.gov (United States)

    Krishna Priya, S; Nagare, R P; Sneha, V S; Sidhanth, C; Bindhya, S; Manasa, P; Ganesan, T S

    2016-08-15

    The conventional view of tumour vascularization is that tumours acquire their blood supply from neighbouring normal stroma. Additional methods of tumour vascularization such as intussusceptive angiogenesis, vasculogenic mimicry, vessel co-option and vasculogenesis have been demonstrated to occur. However, the origin of the endothelial cells and pericytes in the tumour vasculature is not fully understood. Their origin from malignant cells has been shown indirectly in lymphoma and neuroblastoma by immuno-FISH experiments. It is now evident that tumours arise from a small population of cells called cancer stem cells (CSCs) or tumour initiating cells. Recent data suggest that a proportion of tumour endothelial cells arise from cancer stem cells in glioblastoma. This was demonstrated both in vitro and in vivo. The analysis of chromosomal abnormalities in endothelial cells showed identical genetic changes to those identified in tumour cells. However, another report contradicted these results from the earlier studies in glioblastoma and had shown that CSCs give rise to pericytes and not endothelial cells. The main thrust of this review is the critical analysis of the conflicting data from different studies and the remaining questions in this field of research. The mechanism by which this phenomenon occurs is also discussed in detail. The transdifferentiation of CSCs to endothelial cells/pericytes has many implications in the progression and metastasis of the tumours and hence it would be a novel target for antiangiogenic therapy. PMID:26934471

  1. Silk fibroin microtubes for blood vessel engineering.

    Science.gov (United States)

    Lovett, Michael; Cannizzaro, Christopher; Daheron, Laurence; Messmer, Brady; Vunjak-Novakovic, Gordana; Kaplan, David L

    2007-12-01

    Currently available synthetic grafts demonstrate moderate success at the macrovascular level, but fail at the microvascular scale (inner diameter). We report on the development of silk fibroin microtubes for blood vessel repair with several advantages over existing scaffold materials/designs. These microtubes were prepared by dipping straight lengths of stainless steel wire into aqueous silk fibroin, where the addition of poly(ethylene oxide) (PEO) enabled control of microtube porosity. The microtube properties were characterized in terms of pore size, burst strength, protein permeability, enzymatic degradation, and cell migration. Low porosity microtubes demonstrated superior mechanical properties in terms of higher burst pressures, but displayed poor protein permeability; whereas higher porosity tubes had lower burst strengths but increased permeability and enhanced protein transport. The microtubes also exhibited cellular barrier functions as low porosity tubes prevented outward migration of GFP-transduced HUVECs, while the high porosity microtubes allowed a few cells per tube to migrate outward during perfusion. When combined with the biocompatible and suturability features of silk fibroin, these results suggest that silk microtubes, either implanted directly or preseeded with cells, are an attractive biomaterial for microvascular grafts. PMID:17727944

  2. A functional requirement for astroglia in promoting blood vessel development in the early postnatal brain.

    Directory of Open Access Journals (Sweden)

    Shang Ma

    Full Text Available Astroglia are a major cell type in the brain and play a key role in many aspects of brain development and function. In the adult brain, astrocytes are known to intimately ensheath blood vessels and actively coordinate local neural activity and blood flow. During development of the neural retina, blood vessel growth follows a meshwork of astrocytic processes. Several genes have also been implicated in retinal astrocytes for regulating vessel development. This suggests a role of astrocytes in promoting angiogenesis throughout the central nervous system. To determine the roles that astrocytes may play during brain angiogenesis, we employ genetic approaches to inhibit astrogliogenesis during perinatal corticogenesis and examine its effects on brain vessel development. We find that conditional deletion from glial progenitors of orc3, a gene required for DNA replication, dramatically reduces glial progenitor cell number in the subventricular zone and astrocytes in the early postnatal cerebral cortex. This, in turn, results in severe reductions in both the density and branching frequency of cortical blood vessels. Consistent with a delayed growth but not regression of vessels, we find neither significant net decreases in vessel density between different stages after normalizing for cortical expansion nor obvious apoptosis of endothelial cells in these mutants. Furthermore, concomitant with loss of astroglial interactions, we find increased endothelial cell proliferation, enlarged vessel luminal size as well as enhanced cytoskeletal gene expression in pericytes, which suggests compensatory changes in vascular cells. Lastly, we find that blood vessel morphology in mutant cortices recovers substantially at later stages, following astrogliosis. These results thus implicate a functional requirement for astroglia in promoting blood vessel growth during brain development.

  3. Instability and "Sausage-String" Appearance in Blood Vessels during High Blood Pressure

    CERN Document Server

    Alstrøm, P; Colding-Jorgensen, M; Gustafsson, F; Holstein-Rathlou, N H; Alstrom, Preben; Eguiluz, Victor M.; Colding-Jorgensen, Morten; Gustafsson, Finn; Holstein-Rathlou, Niels-Henrik

    1999-01-01

    A new Rayleigh-type instability is proposed to explain the `sausage-string' pattern of alternating constrictions and dilatations formed in blood vessels under influence of a vasoconstricting agent. Our theory involves the nonlinear elasticity characteristics of the vessel wall, and provides predictions for the conditions under which the cylindrical form of a blood vessel becomes unstable.

  4. Instability and `Sausage-String' Appearance in Blood Vessels during High Blood Pressure

    OpenAIRE

    Alstrøm, P.; Eguíluz, Víctor M.; Holstein-Rathlou, Niels-Henrik

    1998-01-01

    A new Rayleigh-type instability is proposed to explain the `sausage-string' pattern of alternating constrictions and dilatations formed in blood vessels under influence of a vasoconstricting agent. Our theory involves the nonlinear elasticity characteristics of the vessel wall, and provides predictions for the conditions under which the cylindrical form of a blood vessel becomes unstable.

  5. Distinct bone marrow blood vessels differentially regulate haematopoiesis.

    Science.gov (United States)

    Itkin, Tomer; Gur-Cohen, Shiri; Spencer, Joel A; Schajnovitz, Amir; Ramasamy, Saravana K; Kusumbe, Anjali P; Ledergor, Guy; Jung, Yookyung; Milo, Idan; Poulos, Michael G; Kalinkovich, Alexander; Ludin, Aya; Kollet, Orit; Shakhar, Guy; Butler, Jason M; Rafii, Shahin; Adams, Ralf H; Scadden, David T; Lin, Charles P; Lapidot, Tsvee

    2016-04-21

    Bone marrow endothelial cells (BMECs) form a network of blood vessels that regulate both leukocyte trafficking and haematopoietic stem and progenitor cell (HSPC) maintenance. However, it is not clear how BMECs balance these dual roles, and whether these events occur at the same vascular site. We found that mammalian bone marrow stem cell maintenance and leukocyte trafficking are regulated by distinct blood vessel types with different permeability properties. Less permeable arterial blood vessels maintain haematopoietic stem cells in a low reactive oxygen species (ROS) state, whereas the more permeable sinusoids promote HSPC activation and are the exclusive site for immature and mature leukocyte trafficking to and from the bone marrow. A functional consequence of high permeability of blood vessels is that exposure to blood plasma increases bone marrow HSPC ROS levels, augmenting their migration and differentiation, while compromising their long-term repopulation and survival. These findings may have relevance for clinical haematopoietic stem cell transplantation and mobilization protocols. PMID:27074509

  6. Lattice BGK Simulations of the Blood Flow in Elastic Vessels

    Institute of Scientific and Technical Information of China (English)

    LU Xiao-Yang; YI Hou-Hui; CHEN Ji-Yao; FANG Hai-Ping

    2006-01-01

    @@ The lattice Boltzmann method is applied to study the flow in elastic blood vessels. The volume-flow rate increases considerably when the compliance constant of the blood vessel is below a critical value. There is a region of the compliance constant in which the average volume-flow rate is dramatically enhanced. A harmonic perturbation of the pressure does not change the behaviour of the average volume-flow rate while the harmonic wave attenuates very quickly along the tube when the resonant period is close to that of the input wave. The model, together with the simulation results, is expected to be helpful to understand the mechanism of the blood volume-flow rate related to the compliance constant of the blood vessel, especially on the dependence of the flux of human blood vessel under weather changes, which has medical significance.

  7. Development of a blood vessel searching device for HMS

    Science.gov (United States)

    Kuroda, Tatsuro; Uenoya, Toshiyuki; Tsuchiya, Kazuyoshi; Uetsuji, Yasutomo; Nakamachi, Eiji

    2007-12-01

    In this study, an automatic blood vessel searching system (BVSS) is newly developed, which is built in the health monitoring system (HMS) and the drug delivery system (DDS) to extract the blood, evaluates the blood sugar level and injects the insulin for the diabetic patients. Main subjects of our BVSS development are 1) a transmittance photo imaging of the finger by using the LED light as a near-infrared light source with peak wave length of 870 nm, and 2) an image processing to detect the location of the center of the blood vessel cross section. The sharp edge focus method was applied in our BVSS to detect the depth of blood vessel. We carried out experiments by using blood vessel phantoms, which consist of an artificial cylindrical blood vessel and skin tissue, which are made of the teflon tube and the silicone rubber. The teflon tube has the size of 0.6 mm in diameter and is filled with the human blood. The experimental results demonstrated that the estimated depth, which is obtained by image analysis corresponding to given depths, shows a good agreement with the real values, and consequently the availability of our BVSS is confirmed.

  8. Tracking blood vessels in human forearms using visual servoing

    DEFF Research Database (Denmark)

    Savarimuthu, Thiusius Rajeeth; Ellekilde, Lars-Peter; Hansen, Morten

    compensation. By using images taken with near-infrared light to locate the blood vessels in a human forearm and using the same images to detects movements of the arm, this paper shows that it is possible make a robot arm, potentially equipped with a needle for drawing the blood, compensate for the movements of...

  9. DETECTION OF BLOOD VESSELS AND MEASUREMENT OF VESSEL WIDTH FOR DIABETIC RETINOPATHY

    Directory of Open Access Journals (Sweden)

    S.Sukanya

    2014-09-01

    Full Text Available The proposed method measures the retinal blood vessel diameter to identify arteriolar narrowing, arteriovenous (AV nicking, branching coefficients to detect early diabetic retinopathy. It utilizes the vessel centerline and edge information to measure the width for a vessel segment. From the input retinal image, the vascular network is extracted using the local entropy thresholding method. The vessel boundaries are extracted using sobel edge detection method. The skeletonization operation is applied to the vascular network and mapping the vessel boundaries and the skeleton image. The branching point detection method is then performed to localize all crossing locations. A rotational invariant mask to search the pixel pairs from the edge image, and calculate the shortest distance pair which provides the vessel width (or diameter for that cross-section. Variation in the width measurement identifies the diabetic retinopathy.

  10. Brain blood vessel segmentation using line-shaped profiles

    International Nuclear Information System (INIS)

    Segmentation of cerebral blood vessels is of great importance in diagnostic and clinical applications, especially for embolization of cerebral aneurysms and arteriovenous malformations (AVMs). In order to perform embolization of the AVM, the structural and geometric information of blood vessels from 3D images is of utmost importance. For this reason, the in-depth segmentation of cerebral blood vessels is usually done as a fusion of different segmentation techniques, often requiring extensive user interaction. In this paper we introduce the idea of line-shaped profiling with an application to brain blood vessel and AVM segmentation, efficient both in terms of resolving details and in terms of computation time. Our method takes into account both local proximate and wider neighbourhood of the processed pixel, which makes it efficient for segmenting large blood vessel tree structures, as well as fine structures of the AVMs. Another advantage of our method is that it requires selection of only one parameter to perform segmentation, yielding very little user interaction. (paper)

  11. Textile blood vessels coated with DLC

    Czech Academy of Sciences Publication Activity Database

    Jelínek, Miroslav; Podlaha, J.; Kocourek, Tomáš; Žížková, V.

    Berlin: Springer, 2009 - (Vander Sloten, J.; Verdonck, P.; Nyssen, M.; Haueisen, J.), s. 2173-2174. (IFMBE Proceedings. vol. 22). ISBN 978-3-540-89207-6. [ECIFMBE 2008. European Conference of the International Federation for Medical and Biological Engineering /4./. Antwerp (BE), 23.11.2008-27.11.2008] Institutional research plan: CEZ:AV0Z10100522 Keywords : PLD * DLC * vascular prostheses * in vivo * textile vessels Subject RIV: BH - Optics, Masers, Lasers http://dx.doi.org/10.1007/978-3-540-89208-3_519

  12. Heritability of retinal vessel diameters and blood pressure

    DEFF Research Database (Denmark)

    Taarnhøj, Nina C B B; Larsen, Michael; Sander, Birgit;

    2006-01-01

    , aged 20 to 46 years, interpolated diameter estimates for the central retinal artery (CRAE), the central retinal vein (CRVE), and the artery-to-vein diameter ratio (AVR) were assessed by analysis of digital gray-scale fundus photographs of right eyes. RESULTS: The heritability was 70% (95% CI: 54...... for CRVE, and 0.67 +/- 0.05 microm for AVR. No significant influence on artery or vein diameters was found for gender, smoking, body mass index (BMI), total cholesterol, fasting blood glucose, or 2-hour oral glucose tolerance test values. CONCLUSIONS: In healthy young adults with normal blood pressure...... and blood glucose, variations in retinal blood vessel diameters and blood pressure were predominantly attributable to genetic effects. A genetic influence may have a role in individual susceptibility to hypertension and other vascular diseases. The results suggest that retinal vessel diameters and the...

  13. OBSERVATIONS ON VASCULAR PATTERN OF CHORIONIC BLOOD VESSELS OF PLACENTA

    Directory of Open Access Journals (Sweden)

    Yousuf Sarwar

    2013-10-01

    Full Text Available ABSTRACT: BACKGROUND: Placenta is a choriodecidual structure develops during pregnancy implanted on the uterine wall and car ries vital functions. It is connected to the foetus through umbilical cord. The branches of umbilical vessels that traverse along foetal surface of placenta are referred as chorionic vessels. There are two different patterns of chorionic vessels – Dispersa l and Magistral. In the dispersal type, the umbilical vessels undergo successive divisions with gradually diminishing caliber towards periphery while in magistral pattern the vessels traverse to the edge of placenta without appreciable decrease in diameter of vessels. The present study has been done for visualization of the pattern of chorionic vessels in placenta obtained from labour room of a tertiary care hospital in eastern Bihar, India. MATERIALS AND METHODS: A total of one hundred and fifty (150 fres h and intact placenta of full term pregnancies collected from Obstetrics & Gynaecology department were included in the study. After washing with distilled water, removal of blood clots were done with slight digital pressure applied over arteries and vein a nd later on by irrigation with saline. The cut end of the umbilical cord was carefully visualized to identify the umbilical arteries and vein. Dye was injected into umbilical vessels under normal physiological pressure and diameter of chorionic blood vesse ls were taken at the center and periphery. Ultimately each vessel was followed and examined to observe the dispersal and magistral pattern of chorionic blood vessels of placenta. RESULTS AND CONCLUSION: Out of the total of one hundred and fifty (150 full term placenta obtained and examined in the Anatomy department during the study period, 64% Dispersal type & 36 % of Magistral type of arterial pattern of branching of chorionic vessels were observed. Vein and its tributaries presented Dispersal pattern in 60% and Magistral pattern in 40%. There is a significant

  14. Customizable engineered blood vessels using 3D printed inserts.

    Science.gov (United States)

    Pinnock, Cameron B; Meier, Elizabeth M; Joshi, Neeraj N; Wu, Bin; Lam, Mai T

    2016-04-15

    Current techniques for tissue engineering blood vessels are not customizable for vascular size variation and vessel wall thickness. These critical parameters vary widely between the different arteries in the human body, and the ability to engineer vessels of varying sizes could increase capabilities for disease modeling and treatment options. We present an innovative method for producing customizable, tissue engineered, self-organizing vascular constructs by replicating a major structural component of blood vessels - the smooth muscle layer, or tunica media. We utilize a unique system combining 3D printed plate inserts to control construct size and shape, and cell sheets supported by a temporary fibrin hydrogel to encourage cellular self-organization into a tubular form resembling a natural artery. To form the vascular construct, 3D printed inserts are adhered to tissue culture plates, fibrin hydrogel is deposited around the inserts, and human aortic smooth muscle cells are then seeded atop the fibrin hydrogel. The gel, aided by the innate contractile properties of the smooth muscle cells, aggregates towards the center post insert, creating a tissue ring of smooth muscle cells. These rings are then stacked into the final tubular construct. Our methodology is robust, easily repeatable and allows for customization of cellular composition, vessel wall thickness, and length of the vessel construct merely by varying the size of the 3D printed inserts. This platform has potential for facilitating more accurate modeling of vascular pathology, serving as a drug discovery tool, or for vessel repair in disease treatment. PMID:26732049

  15. Transdermal drug targeting and functional imaging of tumor blood vessels in the mouse auricle.

    Science.gov (United States)

    Schröder, Hannes; Komljenovic, Dorde; Hecker, Markus; Korff, Thomas

    2016-02-01

    Subcutaneously growing tumors are widely utilized to study tumor angiogenesis and the efficacy of antiangiogenic therapies in mice. To additionally assess functional and morphologic alterations of the vasculature in the periphery of a growing tumor, we exploited the easily accessible and hierarchically organized vasculature of the mouse auricle. By site-specific subcutaneous implantation of a defined preformed mouse B16/F0 melanoma aggregate, a solid tumor nodule developed within 14 d. Growth of the tumor nodule was accompanied by a 4-fold increase in its perfusion as well as a 2- to 4-fold elevated diameter and perfusion of peripheral blood vessels that had connected to the tumor capillary microvasculature. By transdermal application of the anticancer drug bortezomib, tumor growth was significantly diminished by about 50% without provoking side effects. Moreover, perfusion and tumor microvessel diameter as well as growth and perfusion of arterial or venous blood vessels supplying or draining the tumor microvasculature were decreased under these conditions by up to 80%. Collectively, we observed that the progressive tumor growth is accompanied by the enlargement of supplying and draining extratumoral blood vessels. This process was effectively suppressed by bortezomib, thereby restricting the perfusion capacity of both extra and intratumoral blood vessels. PMID:26546130

  16. Electromechanical Model of Blood Flow in Vessels

    OpenAIRE

    Ivo Cap; Barbora Czippelova

    2008-01-01

    The present paper deals with some theoretical derivations connected with very efficient method of solution of hydrodynamic problems of blood flow in human cardiovascular system. The electromechanical analogy of liquid flow in a tube and electromagnetic wave propagating along an electric transmission line is discussed. We have derived a detailed circuit-like model of an elementary section of the elastic tube with viscose Newtonian liquid. The analogy harmonic current electrical cir...

  17. Electromechanical Model of Blood Flow in Vessels

    Directory of Open Access Journals (Sweden)

    Ivo Cap

    2008-01-01

    Full Text Available The present paper deals with some theoretical derivations connected with very efficient method of solution of hydrodynamic problems of blood flow in human cardiovascular system. The electromechanical analogy of liquid flow in a tube and electromagnetic wave propagating along an electric transmission line is discussed. We have derived a detailed circuit-like model of an elementary section of the elastic tube with viscose Newtonian liquid. The analogy harmonic current electrical circuit has been designed

  18. Tumors induce coordinate growth of artery, vein, and lymphatic vessel triads

    International Nuclear Information System (INIS)

    Tumors drive blood vessel growth to obtain oxygen and nutrients to support tumor expansion, and they also can induce lymphatic vessel growth to facilitate fluid drainage and metastasis. These processes have generally been studied separately, so that it is not known how peritumoral blood and lymphatic vessels grow relative to each other. The murine B16-F10 melanoma and chemically-induced squamous cell carcinoma models were employed to analyze large red-colored vessels growing between flank tumors and draining lymph nodes. Immunostaining and microscopy in combination with dye injection studies were used to characterize these vessels. Each peritumoral red-colored vessel was found to consist of a triad of collecting lymphatic vessel, vein, and artery, that were all enlarged. Peritumoral veins and arteries were both functional, as detected by intravenous dye injection. The enlarged lymphatic vessels were functional in most mice by subcutaneous dye injection assay, however tumor growth sometimes blocked lymph drainage to regional lymph nodes. Large red-colored vessels also grew between benign papillomas or invasive squamous cell carcinomas and regional lymph nodes in chemical carcinogen-treated mice. Immunostaining of the red-colored vessels again identified the clustered growth of enlarged collecting lymphatics, veins, and arteries in the vicinity of these spontaneously arising tumors. Implanted and spontaneously arising tumors induce coordinate growth of blood and lymphatic vessel triads. Many of these vessel triads are enlarged over several cm distance between the tumor and regional lymph nodes. Lymphatic drainage was sometimes blocked in mice before lymph node metastasis was detected, suggesting that an unknown mechanism alters lymph drainage patterns before tumors reach draining lymph nodes

  19. Performance Analysis of Retinal Image Blood Vessel Segmentation

    Directory of Open Access Journals (Sweden)

    D.Siva Sundhara Raja

    2014-06-01

    Full Text Available The retinal image diagnosis is an important methodology for diabetic retinopathy detection and analysis. in this paper, the morphological operations and svm classifier are used to detect and segment the blood vessels from the retinal image. the proposed system consists of three stages-first is preprocessing of retinal image to separate the green channel and second stage is retinal image enhancement and third stage is blood vessel segmentation using morphological operations and svm classifier. the performance of the proposed system is analyzed using publicly available dataset.

  20. Blood Vessel Segmentation of Fundus Images by Major Vessel Extraction and Subimage Classification.

    Science.gov (United States)

    Roychowdhury, Sohini; Koozekanani, Dara D; Parhi, Keshab K

    2015-05-01

    This paper presents a novel three-stage blood vessel segmentation algorithm using fundus photographs. In the first stage, the green plane of a fundus image is preprocessed to extract a binary image after high-pass filtering, and another binary image from the morphologically reconstructed enhanced image for the vessel regions. Next, the regions common to both the binary images are extracted as the major vessels. In the second stage, all remaining pixels in the two binary images are classified using a Gaussian mixture model (GMM) classifier using a set of eight features that are extracted based on pixel neighborhood and first and second-order gradient images. In the third postprocessing stage, the major portions of the blood vessels are combined with the classified vessel pixels. The proposed algorithm is less dependent on training data, requires less segmentation time and achieves consistent vessel segmentation accuracy on normal images as well as images with pathology when compared to existing supervised segmentation methods. The proposed algorithm achieves a vessel segmentation accuracy of 95.2%, 95.15%, and 95.3% in an average of 3.1, 6.7, and 11.7 s on three public datasets DRIVE, STARE, and CHASE_DB1, respectively. PMID:25014980

  1. Acrolein generation stimulates hypercontraction in isolated human blood vessels

    International Nuclear Information System (INIS)

    Increased risk of vasospasm, a spontaneous hyperconstriction, is associated with atherosclerosis, cigarette smoking, and hypertension-all conditions involving oxidative stress, lipid peroxidation, and inflammation. To test the role of the lipid peroxidation- and inflammation-derived aldehyde, acrolein, in human vasospasm, we developed an ex vivo model using human coronary artery bypass graft (CABG) blood vessels and a demonstrated acrolein precursor, allylamine. Allylamine induces hypercontraction in isolated rat coronary artery in a semicarbazide-sensitive amine oxidase activity (SSAO) dependent manner. Isolated human CABG blood vessels (internal mammary artery, radial artery, saphenous vein) were used to determine: (1) vessel responses and sensitivity to acrolein, allylamine, and H2O2 exposure (1 μM-1 mM), (2) SSAO dependence of allylamine-induced effects using SSAO inhibitors (semicarbazide, 1 mM; MDL 72274-E, active isomer; MDL 72274-Z, inactive isomer; 100 μM), (3) the vasoactive effects of two other SSAO amine substrates, benzylamine and methylamine, and (4) the contribution of extracellular Ca2+ to hypercontraction. Acrolein or allylamine but not H2O2, benzylamine, or methylamine stimulated spontaneous and pharmacologically intractable hypercontraction in CABG blood vessels that was similar to clinical vasospasm. Allylamine-induced hypercontraction and blood vessel SSAO activity were abolished by pretreatment with semicarbazide or MDL 72274-E but not by MDL 72274-Z. Allylamine-induced hypercontraction also was significantly attenuated in Ca2+-free buffer. In isolated aorta of spontaneously hypertensive rat, allylamine-induced an SSAO-dependent contraction and enhanced norepinephrine sensitivity but not in Sprague-Dawley rat aorta. We conclude that acrolein generation in the blood vessel wall increases human susceptibility to vasospasm, an event that is enhanced in hypertension

  2. FCM Based Blood Vessel Segmentation Method for Retinal Images

    Directory of Open Access Journals (Sweden)

    Nilanjan Dey

    2012-06-01

    Full Text Available Segmentation of blood vessels in retinal images providesearly diagnosis of diseases like glaucoma, diabeticretinopathy and macular degeneration. Among thesediseases occurrence of Glaucoma is most frequent and hasserious ocular consequences that can even lead toblindness, if it is not detected early. The clinical criteria forthe diagnosis of glaucoma include intraocular pressuremeasurement, optic nerve head evaluation, retinal nervefiber layer and visual field defects. This form of bloodvessel segmentation helps in early detection for ophthalmicdiseases, and potentially reduces the risk of blindness.The low-contrast images at the retina owing to narrowblood vessels of the retina are difficult to extract. Theselow contrast images are, however useful in revealingcertain systemic diseases. Motivated by the goals ofimproving detection of such vessels, this present workproposes an algorithm for segmentation of blood vessels,and compares the results between expert ophthalmologists’hand-drawn ground-truths and segmented image (i.e. theoutput of the present work. Sensitivity, specificity, positivepredictive value (PPV, positive likelihood ratio (PLR andaccuracy are used to evaluate overall performance. It isfound that this work segments blood vessels successfullywith sensitivity, specificity, PPV, PLR and accuracy of99.62%, 54.66%, 95.08%, 219.72 and 95.03%,respectively.

  3. Retinal Blood Vessel Segmentation with Optic Disc Pixels Exclusion

    Directory of Open Access Journals (Sweden)

    Randy Cahya Wihandika

    2013-06-01

    Full Text Available The morphological changes of retinal blood vessels are important indicators used to diagnose and monitor the progression of various diseases. A number of retinal blood vessel segmentation methods have been introduced, including the line operator based methods, which have shown satisfactory results. However, the basic line operator method cannot discriminate the pixels around the retinal optic disc, resulting in false classification of those pixels. In this paper, we integrate the detection of pixels around the retinal optic disc to the line operator method so that those pixels can be excluded from the vessel pixels. The method is evaluated on the widely used retinal dataset, the DRIVE dataset. The results demonstrate that the proposed method has made improvements over the basic and the multi-scale line detector with accuracy and area under curve of 0.942 and 0.9521, respectively.

  4. A computational model predicting disruption of blood vessel development.

    Directory of Open Access Journals (Sweden)

    Nicole Kleinstreuer

    2013-04-01

    Full Text Available Vascular development is a complex process regulated by dynamic biological networks that vary in topology and state across different tissues and developmental stages. Signals regulating de novo blood vessel formation (vasculogenesis and remodeling (angiogenesis come from a variety of biological pathways linked to endothelial cell (EC behavior, extracellular matrix (ECM remodeling and the local generation of chemokines and growth factors. Simulating these interactions at a systems level requires sufficient biological detail about the relevant molecular pathways and associated cellular behaviors, and tractable computational models that offset mathematical and biological complexity. Here, we describe a novel multicellular agent-based model of vasculogenesis using the CompuCell3D (http://www.compucell3d.org/ modeling environment supplemented with semi-automatic knowledgebase creation. The model incorporates vascular endothelial growth factor signals, pro- and anti-angiogenic inflammatory chemokine signals, and the plasminogen activating system of enzymes and proteases linked to ECM interactions, to simulate nascent EC organization, growth and remodeling. The model was shown to recapitulate stereotypical capillary plexus formation and structural emergence of non-coded cellular behaviors, such as a heterologous bridging phenomenon linking endothelial tip cells together during formation of polygonal endothelial cords. Molecular targets in the computational model were mapped to signatures of vascular disruption derived from in vitro chemical profiling using the EPA's ToxCast high-throughput screening (HTS dataset. Simulating the HTS data with the cell-agent based model of vascular development predicted adverse effects of a reference anti-angiogenic thalidomide analog, 5HPP-33, on in vitro angiogenesis with respect to both concentration-response and morphological consequences. These findings support the utility of cell agent-based models for simulating a

  5. Method and arrangement for angiography of blood vessels

    International Nuclear Information System (INIS)

    A method and apparatus for angiography in which information contained within multiple serial images of contrast medium flowing through a blood vessel is combined to form a single image having improved vessel edge delineation. More specifically, a method is disclosed whereby a contrast medium opaque to X-rays is injected into a blood vessel distant from an artery section of interest, preferably injected into a vein, whereby the contrast medium is mixed with blood prior to its passing through the artery section. Multiple X-ray images are obtained as the contrast medium and blood mixture flows through the artery section. These multiple images are registered with respect to each other according to a landmark contained within the patient, the landmark having a predetermined relationship to the vessel of interest. The landmark could be a bone, catheter or any other material opaque to X-rays. Density measurements are made with respect to each corresponding image segment or element of the multiple images and are combined to synthesize a composite image. The synthesized image has an edge uncertainty equal to that of one of the individual images. (Auth.)

  6. Blood vessel segmentation for neck and head computed tomography angiography

    OpenAIRE

    Hedblom, Anders

    2013-01-01

    This thesis presents tests and discussions evaluating different methods for doing automatic or semi automatic blood vessel segmentation on single CT data volumes of the head and neck. The two approaches being closest to accomplish this are a bone subtracting registration process, and a more advanced region growing combined with morphology.

  7. The Conditions of Vibrations and Collapse of Human Blood Vessels

    Czech Academy of Sciences Publication Activity Database

    Hemza, J.; Chlup, Hynek; Maršík, František

    Liberec : Technical University of Liberec, 2010 - (Čapek, L.), s. 98-102 ISBN 978-80-7372-648-5. [Human Biomechanics 2010. Sychrov (CZ), 04.10.2010-06.10.2010] Institutional research plan: CEZ:AV0Z20760514 Keywords : viscoelastic properties of human blood vessels * bridging vein * neo-Hooks materialmodel Subject RIV: JJ - Other Materials

  8. Vessel Elasticity Estimation by Normalized Blood Pressure Dynamics

    Czech Academy of Sciences Publication Activity Database

    Jurák, Pavel; Halámek, Josef; Vondra, Vlastimil; Leinveber, Pavel; Plachý, M.; Fráňa, P.; Souček, M.; Kára, T.

    Tel-Aviv : Israel Heart Society, 2008. s. 115. ISBN N. [IDSS 2008 - International Dead Sea Symposium on Cardiac Arrhythmias and Device Therapy /9./. 22.09.2008-24.09.2008, Tel-Aviv] Institutional research plan: CEZ:AV0Z20650511 Keywords : hypertension * vessel compliance * blood pressure * dynamic parameters Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

  9. Circulating fibrocytes stabilize blood vessels during angiogenesis in a paracrine manner.

    Science.gov (United States)

    Li, Jinqing; Tan, Hong; Wang, Xiaolin; Li, Yuejun; Samuelson, Lisa; Li, Xueyong; Cui, Caibin; Gerber, David A

    2014-02-01

    Accumulating evidence supports that circulating fibrocytes play important roles in angiogenesis. However, the specific role of fibrocytes in angiogenesis and the underlying mechanisms remain unclear. In this study, we found that fibrocytes stabilized newly formed blood vessels in a mouse wound-healing model by inhibiting angiogenesis during the proliferative phase and inhibiting blood vessel regression during the remodeling phase. Fibrocytes also inhibited angiogenesis in a Matrigel mouse model. In vitro study showed that fibrocytes inhibited both the apoptosis and proliferation of vascular endothelial cells (VECs) in a permeable support (Transwell) co-culture system. In a three-dimensional collagen gel, fibrocytes stabilized the VEC tubes by decreasing VEC tube density on stimulation with growth factors and preventing VEC tube regression on withdrawal of growth factors. Further mechanistic investigation revealed that fibrocytes expressed many prosurvival factors that are responsible for the prosurvival effect of fibrocytes on VECs and blood vessels. Fibrocytes also expressed angiogenesis inhibitors, including thrombospondin-1 (THBS1). THBS1 knockdown partially blocked the fibrocyte-induced inhibition of VEC proliferation in the Transwell co-culture system and recovered the fibrocyte-induced decrease of VEC tube density in collagen gel. Purified fibrocytes transfected with THBS1 siRNA partially recovered the fibrocyte-induced inhibition of angiogenesis in both the wound-healing and Matrigel models. In conclusion, our findings reveal that fibrocytes stabilize blood vessels via prosurvival factors and anti-angiogenic factors, including THBS1. PMID:24300950

  10. Investigation on artificial blood vessels prepared from bacterial cellulose.

    Science.gov (United States)

    Zang, Shanshan; Zhang, Ran; Chen, Hua; Lu, Yudong; Zhou, Jianhai; Chang, Xiao; Qiu, Guixing; Wu, Zhihong; Yang, Guang

    2015-01-01

    BC (bacterial cellulose) exhibits quite distinctive properties than plant cellulose. The outstanding properties make BC a promising material for preparation of artificial blood vessel. By taking advantage of the high oxygen permeability of PDMS (polydimethylsiloxane) as a tubular template material, a series of BC tubes with a length of 100 mm, a thickness of 1mm and an outer diameter of 4 or 6mm were biosynthesized with the help of Gluconacetobacter xylinum. Through characterization by SEM (scanning electron microscope), tensile testing and thermal analysis, it is demonstrated that BC tubes are good enough for artificial blood vessel with elaborated nano-fiber architecture, qualified mechanical properties and high thermal stability. In addition, measurement of biocompatibility also shows that BC tubes are greatly adaptable to the in vivo environment. The results indicate that BC tubes have great potential for being utilized as tubular scaffold materials in the field of tissue engineering. PMID:25491966

  11. Blood Vessel-Derived Acellular Matrix for Vascular Graft Application

    Directory of Open Access Journals (Sweden)

    Luigi Dall’Olmo

    2014-01-01

    Full Text Available To overcome the issues connected to the use of autologous vascular grafts and artificial materials for reconstruction of small diameter (<6 mm blood vessels, this study aimed to develop acellular matrix- (AM- based vascular grafts. Rat iliac arteries were decellularized by a detergent-enzymatic treatment, whereas endothelial cells (ECs were obtained through enzymatic digestion of rat skin followed by immunomagnetic separation of CD31-positive cells. Sixteen female Lewis rats (8 weeks old received only AM or previously in vitro reendothelialized AM as abdominal aorta interposition grafts (about 1 cm. The detergent-enzymatic treatment completely removed the cellular part of vessels and both MHC class I and class II antigens. One month after surgery, the luminal surface of implanted AMs was partially covered by ECs and several platelets adhered in the areas lacking cell coverage. Intimal hyperplasia, already detected after 1 month, increased at 3 months. On the contrary, all grafts composed by AM and ECs were completely covered at 1 month and their structure was similar to that of native vessels at 3 months. Taken together, our findings show that prostheses composed of AM preseeded with ECs could be a promising approach for the replacement of blood vessels.

  12. Investigation on artificial blood vessels prepared from bacterial cellulose

    International Nuclear Information System (INIS)

    BC (bacterial cellulose) exhibits quite distinctive properties than plant cellulose. The outstanding properties make BC a promising material for preparation of artificial blood vessel. By taking advantage of the high oxygen permeability of PDMS (polydimethylsiloxane) as a tubular template material, a series of BC tubes with a length of 100 mm, a thickness of 1 mm and an outer diameter of 4 or 6 mm were biosynthesized with the help of Gluconacetobacter xylinum. Through characterization by SEM (scanning electron microscope), tensile testing and thermal analysis, it is demonstrated that BC tubes are good enough for artificial blood vessel with elaborated nano-fiber architecture, qualified mechanical properties and high thermal stability. In addition, measurement of biocompatibility also shows that BC tubes are greatly adaptable to the in vivo environment. The results indicate that BC tubes have great potential for being utilized as tubular scaffold materials in the field of tissue engineering. - Highlights: • Bacterial cellulose (BC) can be made into tubular shape through PDMS mold. • BC represents a fine nanofiber network. • The mechanical and thermal properties of BC mimic the situation of real vessel. • BC exhibits attractive biocompatible properties as a substitution of vessel

  13. Investigation on artificial blood vessels prepared from bacterial cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Zang, Shanshan; Zhang, Ran; Chen, Hua; Lu, Yudong; Zhou, Jianhai [Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Chang, Xiao; Qiu, Guixing; Wu, Zhihong [Department of Orthopaedics, Peking Union Medical College Hospital, Beijing 100730 (China); Yang, Guang, E-mail: yang_sunny@yahoo.com [Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2015-01-01

    BC (bacterial cellulose) exhibits quite distinctive properties than plant cellulose. The outstanding properties make BC a promising material for preparation of artificial blood vessel. By taking advantage of the high oxygen permeability of PDMS (polydimethylsiloxane) as a tubular template material, a series of BC tubes with a length of 100 mm, a thickness of 1 mm and an outer diameter of 4 or 6 mm were biosynthesized with the help of Gluconacetobacter xylinum. Through characterization by SEM (scanning electron microscope), tensile testing and thermal analysis, it is demonstrated that BC tubes are good enough for artificial blood vessel with elaborated nano-fiber architecture, qualified mechanical properties and high thermal stability. In addition, measurement of biocompatibility also shows that BC tubes are greatly adaptable to the in vivo environment. The results indicate that BC tubes have great potential for being utilized as tubular scaffold materials in the field of tissue engineering. - Highlights: • Bacterial cellulose (BC) can be made into tubular shape through PDMS mold. • BC represents a fine nanofiber network. • The mechanical and thermal properties of BC mimic the situation of real vessel. • BC exhibits attractive biocompatible properties as a substitution of vessel.

  14. DLC coating of textile blood vessels using PLD

    Czech Academy of Sciences Publication Activity Database

    Kocourek, Tomáš; Jelínek, Miroslav; Vorlíček, Vladimír; Zemek, Josef; Janča, T.; Žížková, V.; Podlaha, J.; Popov, C.

    2008-01-01

    Roč. 93, č. 3 (2008), s. 627-632. ISSN 0947-8396 R&D Projects: GA MPO FI-IM2/068; GA ČR GA202/06/0216 Institutional research plan: CEZ:AV0Z10100522 Keywords : blood vessels * PLD * DLC * sp2 * sp3 Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.884, year: 2008

  15. Transmitted Ultrasound Pressure Variation in Micro Blood Vessel Phantoms

    OpenAIRE

    Qin, Shengping; Kruse, Dustin E; Ferrara, Katherine W.

    2008-01-01

    Silica, cellulose, and polymethylmethacrylate tubes with inner diameters of ten to a few hundred microns are commonly used as blood vessel phantoms in in vitro studies of microbubble or nanodroplet behavior during insonation. However, a detailed investigation of the ultrasonic fields within these micro-tubes has not yet been performed. This technical note provides a theoretical analysis of the ultrasonic fields within micro-tubes. Numerical results show that for the same tube material, the in...

  16. Stem and progenitor cells in biostructure of blood vessel walls

    Directory of Open Access Journals (Sweden)

    Krzysztof Korta

    2013-09-01

    Full Text Available Development of vascular and hematopoietic systems during organogenesis occurs at the same time. During vasculogenesis, a small part of cells does not undergo complete differentiation but stays on this level, “anchored” in tissue structures described as stem cell niches. The presence of blood vessels within tissue stem cell niches is typical and led to identification of niches and ensures that they are functioning. The three-layer biostructure of vessel walls for artery and vein, tunica: intima, media and adventitia, for a long time was defined as a mechanical barrier between vessel light and the local tissue environment. Recent findings from vascular biology studies indicate that vessel walls are dynamic biostructures, which are equipped with stem and progenitor cells, described as vascular wall-resident stem cells/progenitor cells (VW-SC/PC. Distinct zones for vessel wall harbor heterogeneous subpopulations of VW-SC/PC, which are described as “subendothelial or vasculogenic zones”. Recent evidence from in vitro and in vivo studies show that prenatal activity of stem and progenitor cells is not only limited to organogenesis but also exists in postnatal life, where it is responsible for vessel wall homeostasis, remodeling and regeneration. It is believed that VW-SC/PC could be engaged in progression of vascular disorders and development of neointima. We would like to summarize current knowledge about mesenchymal and progenitor stem cell phenotype with special attention to distribution and biological properties of VW-SC/PC in biostructures of intima, media and adventitia niches. It is postulated that in the near future, niches for VW-SC/PC could be a good source of stem and progenitor cells, especially in the context of vessel tissue bioengineering as a new alternative to traditional revascularization therapies.

  17. Understanding and exploiting nanoparticles' intimacy with the blood vessel and blood.

    Science.gov (United States)

    Setyawati, Magdiel Inggrid; Tay, Chor Yong; Docter, Dominic; Stauber, Roland H; Leong, David Tai

    2015-11-21

    While the blood vessel is seldom the target tissue, almost all nanomedicine will interact with blood vessels and blood at some point of time along its life cycle in the human body regardless of their intended destination. Despite its importance, many bionanotechnologists do not feature endothelial cells (ECs), the blood vessel cells, or consider blood effects in their studies. Including blood vessel cells in the study can greatly increase our understanding of the behavior of any given nanomedicine at the tissue of interest or to understand side effects that may occur in vivo. In this review, we will first describe the diversity of EC types found in the human body and their unique behaviors and possibly how these important differences can implicate nanomedicine behavior. Subsequently, we will discuss about the protein corona derived from blood with foci on the physiochemical aspects of nanoparticles (NPs) that dictate the protein corona characteristics. We would also discuss about how NPs characteristics can affect uptake by the endothelium. Subsequently, mechanisms of how NPs could cross the endothelium to access the tissue of interest. Throughout the paper, we will share some novel nanomedicine related ideas and insights that were derived from the understanding of the NPs' interaction with the ECs. This review will inspire more exciting nanotechnologies that had accounted for the complexities of the real human body. PMID:26239875

  18. Scanning electron microscopy of irradiated recipient blood vessels in head and neck free flaps

    International Nuclear Information System (INIS)

    Irradiated and control recipient blood vessels in a similar patient population were studied with scanning electron microscopy. The vessels that were biopsied were then anastomosed to a free flap. Irradiated arteries display a significantly greater wall thickness and higher incidence of intimal dehiscence compared with control arteries. Fibrin deposition, microthrombi, and endothelium cell dehiscence are present more frequently in irradiated vessels than in control vessels. Details of the preparation and anastomotic technique for irradiated blood vessels are discussed. Microvascular surgery in irradiated human blood vessels carries with it a higher risk of thrombosis due to preexisting vessel wall damage. This risk can be minimized by experience and attention to detail

  19. Over-expression of Slit2 induces vessel formation and changes blood vessel permeability in mouse brain

    Institute of Scientific and Technical Information of China (English)

    Hai-xiong HAN; Jian-guo GENG

    2011-01-01

    Aim:To investigate the effect of the axon guidance cue Slit2 on the density of blood vessels and permeability of the blood-brain barrier in mouse brain.Methods:hSlit2 transgenic mouse line was constructed,and the phenotypes of the mice were compared with wild-type mice in respect to the lateral ventricle (LV),ventricle pressure,and the choroids plexus.An in vivo Miles permeability assay and an amyloid-β permeability assay were used to assess the permeability of brain blood vessels.Brain vessel casting and intracerebral hemorrhage models were built to investigate vessel density in the transgenic mice.An in vitro permeability assay was used to test whether Slit2 could change the permeability and tight junctions of blood vessel endothelial cells.Results:Hydrocephalus occurred in some transgenic mice,and a significantly larger lateral ventricle area and significantly higher ventricle pressure were observed in the transgenic mice.The transgenic mice displayed changed construction of the choroids plexus,which had more micro vessels,dilated vessels,gaps between epithelial cells and endothelial cells than wild-type mice.Slit2 significantly increased brain vessel density and the permeability of brain vessels to large molecules.These blood vessels were more sensitive to cues that induce brain hemorrhage.At the cellular level,Slit2 disturbed the integrity of tight junctions in blood vessel endothelial cells and improved the permeability of the endothelial cell layer.Thus,it promoted the entry of amyloid-β peptides from the serum into the central nervous system,where they bound to neurons.Conclusion:Slit2 increases vessel density and permeability in the brains of transgenic mice.Thus,Slit2 induces numerous changes in brain vessels and the barrier system.

  20. Modeling Of Blood Vessel Constriction In 2-D Case Using Molecular Dynamics Method

    CERN Document Server

    Rendi, Mohamad; Viridi, Sparisoma

    2013-01-01

    Blood vessel constriction is simulated with particle-based method using a molecular dynamics authoring software known as Molecular Workbench (WM). Blood flow and vessel wall, the only components considered in constructing a blood vessel, are all represented in particle form with interaction potentials: Lennard-Jones potential, push-pull spring potential, and bending spring potential. Influence of medium or blood plasma is accommodated in plasma viscosity through Stokes drag force. It has been observed that pressure p is increased as constriction c is increased. Leakage of blood vessel starts at 80 % constriction, which shows existence of maximum pressure that can be overcome by vessel wall.

  1. Angiogenesis and blood vessel stability in inflammatory arthritis.

    LENUS (Irish Health Repository)

    Kennedy, Aisling

    2012-02-01

    OBJECTIVE: To assess blood vessel stability in inflammatory synovial tissue (ST) and to examine neural cell adhesion molecule (NCAM), oxidative DNA damage, and hypoxia in vivo. METHODS: Macroscopic vascularity and ST oxygen levels were determined in vivo in patients with inflammatory arthritis who were undergoing arthroscopy. Vessel maturity\\/stability was quantified in matched ST samples by dual immunofluorescence staining for factor VIII (FVIII)\\/alpha-smooth muscle actin (alpha-SMA). NCAM and 8-oxo-7,8-dihydro-2\\'-deoxyguanosine (8-oxodG) were examined by immunohistochemistry. Angiogenesis was assessed in vitro, using human dermal endothelial cells (HDECs) in a Matrigel tube formation assay. RESULTS: A significant number of immature vessels (showing no pericyte recruitment) was observed in tissue from patients with inflammatory arthritis (P < 0.001), in contrast to osteoarthritic and normal tissue, which showed complete recruitment of pericytes. Low in vivo PO(2) levels in the inflamed joint (median [range] 22.8 [3.2-54.1] mm Hg) were inversely related to increased macroscopic vascularity (P < 0.04) and increased microscopic expression of FVIII and alpha-SMA (P < 0.04 and P < 0.03, respectively). A significant proportion of vessels showed focal expression of NCAM and strong nuclear 8-oxodG expression, implicating a loss of EC-pericyte contact and increased DNA damage, levels of which were inversely associated with low in vivo PO(2) (P = 0.04 for each comparison). Circulating cells were completely negative for 8-oxodG. Exposure of HDEC to 3% O(2) (reflecting mean ST in vivo measurements) significantly increased EC tube formation (P < 0.05). CONCLUSION: Our findings indicate the presence of unstable vessels in inflamed joints associated with hypoxia, incomplete EC-pericyte interactions, and increased DNA damage. These changes may further contribute to persistent hypoxia in the inflamed joint to further drive this unstable microenvironment.

  2. Plasma membrane electron transport in frog blood vessels

    Indian Academy of Sciences (India)

    Rashmi P Rao; K Nalini; J Prakasa Rao

    2009-12-01

    In an attempt to see if frog blood vessels possess a plasma membrane electron transport system, the postcaval vein and aorta isolated from Rana tigrina were tested for their ability to reduce ferricyanide, methylene blue, and 2,6-dichloroindophenol. While the dyes remained unchanged, ferricyanide was reduced to ferrocyanide. This reduction was resistant to inhibition by cyanide and azide. Heptane extraction or formalin fixation of the tissues markedly reduced the capability to reduce ferricyanide. Denuded aortas retained only 30% of the activity of intact tissue. Our results indicate that the amphibian postcaval vein and aorta exhibit plasma membrane electron transport

  3. Segmentation of blood vessels from red-free and fluorescein retinal images.

    Science.gov (United States)

    Martinez-Perez, M Elena; Hughes, Alun D; Thom, Simon A; Bharath, Anil A; Parker, Kim H

    2007-02-01

    The morphology of the retinal blood vessels can be an important indicator for diseases like diabetes, hypertension and retinopathy of prematurity (ROP). Thus, the measurement of changes in morphology of arterioles and venules can be of diagnostic value. Here we present a method to automatically segment retinal blood vessels based upon multiscale feature extraction. This method overcomes the problem of variations in contrast inherent in these images by using the first and second spatial derivatives of the intensity image that gives information about vessel topology. This approach also enables the detection of blood vessels of different widths, lengths and orientations. The local maxima over scales of the magnitude of the gradient and the maximum principal curvature of the Hessian tensor are used in a multiple pass region growing procedure. The growth progressively segments the blood vessels using feature information together with spatial information. The algorithm is tested on red-free and fluorescein retinal images, taken from two local and two public databases. Comparison with first public database yields values of 75.05% true positive rate (TPR) and 4.38% false positive rate (FPR). Second database values are of 72.46% TPR and 3.45% FPR. Our results on both public databases were comparable in performance with other authors. However, we conclude that these values are not sensitive enough so as to evaluate the performance of vessel geometry detection. Therefore we propose a new approach that uses measurements of vessel diameters and branching angles as a validation criterion to compare our segmented images with those hand segmented from public databases. Comparisons made between both hand segmented images from public databases showed a large inter-subject variability on geometric values. A last evaluation was made comparing vessel geometric values obtained from our segmented images between red-free and fluorescein paired images with the latter as the "ground truth

  4. PET/CT imaging of atherosclerotic blood vessel alterations

    International Nuclear Information System (INIS)

    Atherosclerosis is a chronic inflammatory disease of middle sized and large vessels with sequelae comprising the most frequent causes of death in the Western world. Modern imaging modalities are being introduced for the study of atherosclerosis with emphasis on the detection of vulnerable plaques. The hybrid imaging method PET/CT presents advantages for the localization of vulnerable plaques based on the uptake of various molecular imaging agents indicative of inflammatory processes. Using semiquantitative image analysis fluorodeoxyglucose (FDG) uptake in large peripheral vessels has been identified in a series of 21 patients, who were scanned first with the previous generation of PET/CT scanner and subsequently with a new generation apparatus, after a mean interval of 6.5 months. The mean ratio of FDG uptake in the walls of eight large vessels to the blood-pool activity (TBR) was nearly identical in the two PET/CT sessions (TBR1 1.26 versus TBR2 1.28; p=n.s.), indicating independence of the TBR endpoint from the particular instrumentation. (orig.)

  5. War injuries of the blood vessels of the extremities

    Directory of Open Access Journals (Sweden)

    Radulović Svetozar

    2002-01-01

    Full Text Available Treatment results of 200 injured with the lesions of 282 magisterial blood vessels were analyzed. All were combat injuries, and the majority was caused by the fragments of explosive device. The mechanism of such the injuries produced large defects of soft tissues as well as the high level of the wound contamination, which aggravated reconstructive procedures and increased the risk of infection. In the majority of cases anatomic reconstruction of the artery was performed, and the ligature was used only in the case of graft infection and in the injuries of one artery of the lower leg or the forearm. The majority of injuries was solved by lateral suture or patch plastic, since postoperative constriction caused by those methods did not cause greater hemodynamic disorders due to the size of venous lumen. The duration of ischemic interval was of the utmost importance for the favorable final result of the treatment, as well as the adequate debridement of the wound, good soft-tissue cover of the reconstructed blood vessel and precise a traumatic technique. Total percentage of amputations was 14.5%, and all were involving the lower extremities, and were mostly caused by popliteal artery lesion.

  6. Mathematical Model of Blood Flow in Small Blood Vessel in the Presence of Magnetic Field

    Directory of Open Access Journals (Sweden)

    Rekha Bali

    2011-02-01

    Full Text Available A mathematical model for blood flow in the small blood vessel in the presence of magnetic field is presented in this paper. We have modeled the two phase model for the blood flow consists of a central core of suspended erythrocytes and cell-free layer surrounding the core. The system of differential equations has been solved analytically. We have obtained the result for velocity, flow rate and effective viscosity in presence of peripheral layer and magnetic field .All the result has been obtained and discussed through graphs.

  7. Angiopoietin-4 increases permeability of blood vessels and promotes lymphatic dilation.

    Science.gov (United States)

    Kesler, Cristina T; Pereira, Ethel R; Cui, Cheryl H; Nelson, Gregory M; Masuck, David J; Baish, James W; Padera, Timothy P

    2015-09-01

    The angiopoietin (Ang) ligands are potential therapeutic targets for lymphatic related diseases, which include lymphedema and cancer. Ang-1 and Ang-2 functions are established, but those of Ang-4 are poorly understood. We used intravital fluorescence microscopy to characterize Ang-4 actions on T241 murine fibrosarcoma-associated vessels in mice. The diameters of lymphatic vessels draining Ang-4- or VEGF-C (positive control)-expressing tumors increased to 123 and 135 μm, respectively, and parental, mock-transduced (negative controls) and tumors expressing Ang-1 or Ang-2 remained at baseline (∼60 μm). Ang-4 decreased human dermal lymphatic endothelial cell (LEC) monolayer permeability by 27% while increasing human dermal blood endothelial cell (BEC) monolayer permeability by 200%. In vivo, Ang-4 stimulated a 4.5-fold increase in tumor-associated blood vessel permeability compared with control when measured using intravital quantitative multiphoton microscopy. Ang-4 activated receptor signaling in both LECs and BECs, evidenced by tyrosine kinase with Ig and endothelial growth factor homology domains-2 (TIE2) receptor, protein kinase B, and Erk1,2 phosphorylation detectable by immunoblotting. These data suggest that Ang-4 actions are mediated through cell-type-specific networks and that lymphatic vessel dilation occurs secondarily to increased vascular leakage. Ang-4 also promoted survival of LECs. Thus, blocking Ang-4 may prune the draining lymphatic vasculature and decrease interstitial fluid pressure (IFP) by reducing vascular permeability. PMID:25977256

  8. Two and Three Dimensional Blood Flow Simulations in Different Types of Blood Vessels

    Directory of Open Access Journals (Sweden)

    Balazs ALBERT

    2015-12-01

    Full Text Available In this paper we present a synthesis of our results obtained on blood flow simulation in different types of blood vessels. We present first some remarks on the wall shear stress (WSS in the case of a human abdominal aortic aneurysm (AAA, and then we concentrate on the mechanical conditions which would lead to the “rupture” of the vascular vessel with aneurysm and implicitly to a possible stroke. We also make some investigations on the Fahraeus-Lindqvist effect in arterioles. Considering an axial-symmetric reservoir full of blood and which is linked to an arteriole (with the same particular geometry, we have pointed out the concentration of the red blood cells in this arteriole towards the core of the vessel. To improve our work we have considered a real three-dimensional geometry, which is a serious jump versus our previous results, where only the axial-symmetric geometries were considered. In this respect we have reconsidered the case of a carotid artery stenosis with and without a stent.

  9. Pattern of blood vessels in eyes with coloboma

    Directory of Open Access Journals (Sweden)

    Gopal Lingam

    2013-01-01

    Full Text Available Background: Choroidal coloboma, especially with optic disc involvement affects the blood vessel (BV pattern in the fundus. Aim: The aim of this study was to report the observations on the pattern of retinal BVs in eyes with fundus coloboma. Design: Retrospective observational study. Materials and Methods: Twenty four eyes of 19 patients with fundus coloboma and the disc involvement in the coloboma was classified according to a previous publication. Results: Four varieties of BVs were identified in the area of coloboma - BVs that were continuous with those arising from the optic disc; vessels emanating from the floor of coloboma whose continuity with central retinal artery or its branches could be indirectly established; and those emanating from the floor of coloboma whose continuity with central retinal artery could not be established. In addition, extraocular BVs were visible through the thinned sclera. The retinal BVs often traversed the coloboma to reach the normal retina. The disc itself was found to be small and had no physiological cup (if not colobomatous. Conclusions: One should be aware of the major BVs transgressing the coloboma while performing relaxing cuts in the intercalary membrane, during the surgery for retinal detachments in eyes with coloboma. Physiological cup is usually absent (when the disc is not colobomatous. Hence, any cupping in such eyes should be viewed with suspicion.

  10. Differentiation of smooth muscle progenitor cells in peripheral blood and its application in tissue engineered blood vessels

    Institute of Scientific and Technical Information of China (English)

    Shang-zhe XIE; Ning-tao FANG; Shui LIU; Ping ZHOU; Yi ZHANG; Song-mei WANG; Hong-yang GAO; Luan-feng PAN

    2008-01-01

    Background: A major shortcoming in tissue engineered blood vessels (TEBVs) is the lack of healthy and easily attainable smooth muscle cells (SMCs). Smooth muscle progenitor cells (SPCs), especially from peripheral blood, may offer an alternative cell source for tissue engineering involving a less invasive harvesting technique. Methods: SPCs were isolated from 5-ml fresh rat peripheral blood by density-gradient centrifugation and cultured for 3 weeks in endothelial growth medium-2-MV (EGM-2-MV) medium containing platelet-derived growth factor-BB (PDGF BB). Before seeded on the synthesized scaffold, SPC-derived smooth muscle outgrowth cell (SOC) phenotypes were assessed by immuno-fluorescent staining, Western blot analysis, and reverse transcription polymerase chain reaction (RT-PCR). The cells were seeded onto the silk fibroin-modified poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (SF-PHBHHx) scaffolds by 6×104 cells/cm'2 and cultured under the static con-dition for 3 weeks. The growth and proliferation of the seeded cells on the scaffold were analyzed by 3-(4,5-dimethylthiazol-2-yl)-diphenyltetrazolium bromide (MTT) assay, scanning electron microscope (SEM), and 4,6-diamidino-2-phenylindole (DAPI) staining. Results: SOCs displayed specific "hill and valley" morphology, expressed the specific markers of the SMC lineage: protein, and extracellular matrix components elastin and matrix Gla protein (MGP), as well as vascular endothelial growth factor (VEGF). After seeded on the SF-PHBHHx scaffold, the cells showed excellent metabolic activity and proliferation. Conclusion: SPCs isolated from peripheral blood can be differentiated into the SMCs in vitro and have an impressive growth potential in the biodegradable synthesized scaffold. Thus, SPCs may be a promising cell source for constructing TEBVs.

  11. Blood Vessel Normalization in the Hamster Oral Cancer Model for Experimental Cancer Therapy Studies

    Energy Technology Data Exchange (ETDEWEB)

    Ana J. Molinari; Romina F. Aromando; Maria E. Itoiz; Marcela A. Garabalino; Andrea Monti Hughes; Elisa M. Heber; Emiliano C. C. Pozzi; David W. Nigg; Veronica A. Trivillin; Amanda E. Schwint

    2012-07-01

    Normalization of tumor blood vessels improves drug and oxygen delivery to cancer cells. The aim of this study was to develop a technique to normalize blood vessels in the hamster cheek pouch model of oral cancer. Materials and Methods: Tumor-bearing hamsters were treated with thalidomide and were compared with controls. Results: Twenty eight hours after treatment with thalidomide, the blood vessels of premalignant tissue observable in vivo became narrower and less tortuous than those of controls; Evans Blue Dye extravasation in tumor was significantly reduced (indicating a reduction in aberrant tumor vascular hyperpermeability that compromises blood flow), and tumor blood vessel morphology in histological sections, labeled for Factor VIII, revealed a significant reduction in compressive forces. These findings indicated blood vessel normalization with a window of 48 h. Conclusion: The technique developed herein has rendered the hamster oral cancer model amenable to research, with the potential benefit of vascular normalization in head and neck cancer therapy.

  12. Pericyte coverage of abnormal blood vessels in myelofibrotic bone marrows

    DEFF Research Database (Denmark)

    Zetterberg, Eva; Vannucchi, Alessandro M; Migliaccio, Anna Rita;

    2007-01-01

    BACKGROUND AND OBJECTIVES: Myelofibrotic bone marrow displays abnormal angiogenesis but the pathogenic mechanisms of this are poorly understood. Since pericyte abnormalities are described on solid tumor vessels we studied whether vessel morphology and pericyte coverage in bone marrow samples from...

  13. Blood Vessel Deformations on Microsecond Time Scales by Ultrasonic Cavitation

    OpenAIRE

    Chen, Hong; Kreider, Wayne; Brayman, Andrew A.; Bailey, Michael R.; Matula, Thomas J.

    2011-01-01

    Transient interactions among ultrasound, microbubbles, and microvessels were studied using high-speed photomicrography. We observed liquid jets, vessel distention (motion outward against the surrounding tissue), and vessel invagination (motion inward toward the lumen). Contrary to current paradigms, liquid jets were directed away from the nearest vessel wall and invagination exceeded distention. These observations provide insight into the mechanics of bubble-vessel interactions, which appear ...

  14. Selective irradiation of the blood vessels by using boron neutron capture reaction - development and its utilization

    International Nuclear Information System (INIS)

    Full text: The purposes are development of the method to irradiate blood vessels selectively by using B-10(n, alpha) Li-7 reaction and examination of its effect on tumor and normal tissues. We made BSH-enclosed large size liposome (=300 nm) conjugated with PEG ; BSH-PEG-liposome. This type liposome is thought to escapes from macrophage in the liver, and can stay in the blood at high concentration level for long time. They are also considered not to be able to leak from the vessels into the surrounding tissues. If they receive neutron, B-10 emits extreme short-range (<9 micron) alpha-particle and recoil Li-7 nucleus. C3H/He mice and tumor model SCCVII were used to examine the character and effect of this type liposome. Thermal neutron irradiation was performed by KUR heavy water facility and B-10 concentrations in the blood or tissues were measured by prompt gamma-ray spectrometry. The B-10 concentration ratio between blood and tumor 30 minutes after BSH-PEG-liposome administration was 35- 40, and this ratio was stable for several hours. The effect on the tumors that received neutrons was examined by colony formation assay. The tumor cell survival rate of the BSH-PEG-liposome neutron group was very slightly suppressed in comparison with that of neutron alone group, however, the growth of the tumors was remarkably suppressed in BSH-PEG-liposome neutron group. In the mice that received whole body neutron irradiation after BSH-PEF-liposome injection, the mouse group of 50 Gy to the endothelium of the vessel did exhibit no death, and in the groups of 127 and 183 Gy, all individuals died. But diarrhea and bloody anal discharge that suggested radiation intestinal death were not observed at all. Cause of the death seemed to be bone marrow death

  15. Biological and engineering design considerations for vascular tissue engineered blood vessels (TEBVs)

    OpenAIRE

    Fernandez, Cristina E.; Achneck, Hardean E.; Reichert, William M.; Truskey, George A.

    2014-01-01

    Considerable advances have occurred in the development of tissue-engineered blood vessels (TEBVs) to repair or replace injured blood vessels, or as in vitro systems for drug toxicity testing. Here we summarize approaches to produce TEBVs and review current efforts to (1) identify suitable cell sources for the endothelium and vascular smooth muscle cells, (2) design the scaffold to mimic the arterial mechanical properties and (3) regulate the functional state of the cells of the vessel wall. I...

  16. An Experimental Study to Replace the Thoracic Descending Aorta for Pigs with a Self-Made Sutureless Blood Vessel

    OpenAIRE

    Song, Fenglin; Zhou, Wenwu; Tang, Tao; Li, Xiaobing; Wu, Xiaoming; Yang, Jinfu

    2014-01-01

    To simplify the procedure of blood vessel replacement operation and shorten the vascular anastomosis time, we developed a special artificial blood vessel which can be connected to native blood vessels without suture. The self-made sutureless blood vessel (SMSBV) was made from two titanium connectors and a Gore-Tex graft. To investigate blood compatibility and histocompatibility of the SMSBV, we carried thoracic descending aorta replacement using either SMSBV or Gore-Tex, respectively, in pigs...

  17. An Experimental Study to Replace the Thoracic Descending Aorta for Pigs with a Self-Made Sutureless Blood Vessel

    OpenAIRE

    2014-01-01

    To simplify the procedure of blood vessel replacement operation and shorten the vascular anastomosis time, we developed a special artificial blood vessel which can be connected to native blood vessels without suture. The self-made sutureless blood vessel (SMSBV) was made from two titanium connectors and a Gore-Tex graft. To investigate blood compatibility and histocompatibility of the SMSBV, we carried thoracic descending aorta replacement using either SMSBV or Gore-Tex,...

  18. Tumor blood vessels formation in osteosarcoma:vasculogenesis mimicry

    Institute of Scientific and Technical Information of China (English)

    蔡宣松; 贾永伟; 梅炯; 汤如勇

    2004-01-01

    Background Osteosarcoma is characterized by high neovascularization and a high propensity for metastasis through bloodstream. This study was to examine whether there is evidence for vasculogenic mimicry in osteosarcoma and to illustrate mechanism of tumor blood vessels formation in osteosarcoma.Methods Osteosarcoma cell lines (U-2OS) were tested for their ability to form tubular networks in three-dimensional culture containing type Ⅰ collagen. The structures of the tubular networks were observed with phase contrast microscope and transmission electron microscope (TEM). Morphometric studies using hematoxylin and eosin (HE) stain and CD31 immunohistochemical stain to show tumor-lined channels in human osteosarcoma were also performed.Results Observation with light microscope and TEM showed that highly aggressive osteosarcoma cell lines (U-2OS) formed networks containing channels when grown in three-dimensional culture containing type Ⅰ collagen, in the absence of endothelial cells or fibroblasts. Morphometric observation using HE stain and CD31 immunohistochemical stain showed that tumor cell-lined channels were also detected in vivo in osteosarcoma; by comparison, all vascular areas in the pedicel of osteochondroma or outside osteochondroma were endothelial-lined.Conclusion These observations strongly suggest that aggressive osteosarcoma cells may generate vascular channels that facilitate tumor perfusion independent of tumor angiogenesis and have the ability of vasculogenic mimicry.

  19. Transmitted ultrasound pressure variation in micro blood vessel phantoms.

    Science.gov (United States)

    Qin, Shengping; Kruse, Dustin E; Ferrara, Katherine W

    2008-06-01

    Silica, cellulose and polymethylmethacrylate tubes with inner diameters of ten to a few hundred microns are commonly used as blood vessel phantoms in in vitro studies of microbubble or nanodroplet behavior during insonation. However, a detailed investigation of the ultrasonic fields within these micro-tubes has not yet been performed. This work provides a theoretical analysis of the ultrasonic fields within micro-tubes. Numerical results show that for the same tube material, the interaction between the micro-tube and megaHertz-frequency ultrasound may vary drastically with incident frequency, tube diameter and wall thickness. For 10 MHz ultrasonic insonation of a polymethylmethacrylate (PMMA) tube with an inner diameter of 195 microm and an outer diameter of 260 microm, the peak pressure within the tube can be up to 300% of incident pressure amplitude. However, using 1 MHz ultrasound and a silica tube with an inner diameter of 12 microm and an outer diameter of 50 microm, the peak pressure within the tube is only 12% of the incident pressure amplitude and correspondingly, the spatial-average-time-average intensity within the tube is only 1% of the incident intensity. PMID:18395962

  20. Effect of non-Newtonian characteristics of blood on magnetic particle capture in occluded blood vessel

    Energy Technology Data Exchange (ETDEWEB)

    Bose, Sayan; Banerjee, Moloy, E-mail: moloy_kb@yahoo.com

    2015-01-15

    Magnetic nanoparticles drug carriers continue to attract considerable interest for drug targeting in the treatment of cancer and other pathological conditions. Magnetic carrier particles with surface-bound drug molecules are injected into the vascular system upstream from the desired target site, and are captured at the target site via a local applied magnetic field. Herein, a numerical investigation of steady magnetic drug targeting (MDT) using functionalized magnetic micro-spheres in partly occluded blood vessel having a 90° bent is presented considering the effects of non-Newtonian characteristics of blood. An Eulerian–Lagrangian technique is adopted to resolve the hemodynamic flow and the motion of the magnetic particles in the flow using ANSYS FLUENT. An implantable infinitely long cylindrical current carrying conductor is used to create the requisite magnetic field. Targeted transport of the magnetic particles in a partly occluded vessel differs distinctly from the same in a regular unblocked vessel. Parametric investigation is conducted and the influence of the insert configuration and its position from the central plane of the artery (z{sub offset}), particle size (d{sub p}) and its magnetic property (χ) and the magnitude of current (I) on the “capture efficiency” (CE) is reported. Analysis shows that there exists an optimum regime of operating parameters for which deposition of the drug carrying magnetic particles in a target zone on the partly occluded vessel wall can be maximized. The results provide useful design bases for in vitro set up for the investigation of MDT in stenosed blood vessels. - Highlights: • Two counter rotating vortices forces the fluid flow back through the more viscous region. • The existence of strong recirculation zone just downstream side of the occlusion. • Configuration 4 produces the better efficient MDT system. • Modified Casson model predicts the highest value of CE, whereas the generalized power law gives

  1. Effect of non-Newtonian characteristics of blood on magnetic particle capture in occluded blood vessel

    International Nuclear Information System (INIS)

    Magnetic nanoparticles drug carriers continue to attract considerable interest for drug targeting in the treatment of cancer and other pathological conditions. Magnetic carrier particles with surface-bound drug molecules are injected into the vascular system upstream from the desired target site, and are captured at the target site via a local applied magnetic field. Herein, a numerical investigation of steady magnetic drug targeting (MDT) using functionalized magnetic micro-spheres in partly occluded blood vessel having a 90° bent is presented considering the effects of non-Newtonian characteristics of blood. An Eulerian–Lagrangian technique is adopted to resolve the hemodynamic flow and the motion of the magnetic particles in the flow using ANSYS FLUENT. An implantable infinitely long cylindrical current carrying conductor is used to create the requisite magnetic field. Targeted transport of the magnetic particles in a partly occluded vessel differs distinctly from the same in a regular unblocked vessel. Parametric investigation is conducted and the influence of the insert configuration and its position from the central plane of the artery (zoffset), particle size (dp) and its magnetic property (χ) and the magnitude of current (I) on the “capture efficiency” (CE) is reported. Analysis shows that there exists an optimum regime of operating parameters for which deposition of the drug carrying magnetic particles in a target zone on the partly occluded vessel wall can be maximized. The results provide useful design bases for in vitro set up for the investigation of MDT in stenosed blood vessels. - Highlights: • Two counter rotating vortices forces the fluid flow back through the more viscous region. • The existence of strong recirculation zone just downstream side of the occlusion. • Configuration 4 produces the better efficient MDT system. • Modified Casson model predicts the highest value of CE, whereas the generalized power law gives the least

  2. Primo Vascular System Accompanying a Blood Vessel from Tumor Tissue and a Method to Distinguish It from the Blood or the Lymph System

    Directory of Open Access Journals (Sweden)

    Jaekwan Lim

    2013-01-01

    Full Text Available A primo vessel was observed in the abdominal cavity in the lung cancer mouse model, and its function as an extra metastatic path was observed. In this work, we found a primo vessel accompanying a blood vessel emanating from a tumor in the skin. We also presented simple and efficient criteria to distinguish a primo vessel from a blood or a lymph vessel and from a nerve. The criteria for using DAPI and Phalloidin will be useful in clinical situations to find and identify the primo vessels among the blood vessels, lymph vessels, or nerves in the tissue surrounding a tumor such as a melanoma or breast cancer.

  3. Development of an accurate 3D blood vessel searching system using NIR light

    Science.gov (United States)

    Mizuno, Yoshifumi; Katayama, Tsutao; Nakamachi, Eiji

    2010-02-01

    Health monitoring system (HMS) and drug delivery system (DDS) require accurate puncture by needle for automatic blood sampling. In this study, we develop a miniature and high accurate automatic 3D blood vessel searching system. The size of detecting system is 40x25x10 mm. Our searching system use Near-Infrared (NIR) LEDs, CMOS camera modules and image processing units. We employ the stereo method for searching system to determine 3D blood vessel location. Blood vessel visualization system adopts hemoglobin's absorption characterization of NIR light. NIR LED is set behind the finger and it irradiates Near Infrared light for the finger. CMOS camera modules are set in front of the finger and it captures clear blood vessel images. Two dimensional location of the blood vessel is detected by luminance distribution of the image and its depth is calculated by the stereo method. 3D blood vessel location is automatically detected by our image processing system. To examine the accuracy of our detecting system, we carried out experiments using finger phantoms with blood vessel diameters, 0.5, 0.75, 1.0mm, at the depths, 0.5 ~ 2.0 mm, under the artificial tissue surface. Experimental results of depth obtained by our detecting system showed good agreements with given depths, and the availability of this system is confirmed.

  4. Estimation of vessel diameter and blood flow dynamics from laser speckle images

    DEFF Research Database (Denmark)

    Postnov, Dmitry D.; Tuchin, Valery V.; Sosnovtseva, Olga

    2016-01-01

    Laser speckle imaging is a rapidly developing method to study changes of blood velocity in the vascular networks. However, to assess blood flow and vascular responses it is crucial to measure vessel diameter in addition to blood velocity dynamics. We suggest an algorithm that allows for dynamical...... masking of a vessel position and measurements of it's diameter from laser speckle images. This approach demonstrates high reliability and stability....

  5. Human Blood-Vessel-Derived Stem Cells for Tissue Repair and Regeneration

    OpenAIRE

    Chien-Wen Chen; Mirko Corselli; Bruno Péault; Johnny Huard

    2012-01-01

    Multipotent stem/progenitor cells with similar developmental potentials have been independently identified from diverse human tissue/organ cultures. The increasing recognition of the vascular/perivascular origin of mesenchymal precursors suggested blood vessels being a systemic source of adult stem/progenitor cells. Our group and other laboratories recently isolated multiple stem/progenitor cell subsets from blood vessels of adult human tissues. Each of the three structural layers of blood ve...

  6. Estimation of vessel diameter and blood flow dynamics from laser speckle images

    Science.gov (United States)

    Postnov, Dmitry D.; Tuchin, Valery V.; Sosnovtseva, Olga

    2016-01-01

    Laser speckle imaging is a rapidly developing method to study changes of blood velocity in the vascular networks. However, to assess blood flow and vascular responses it is crucial to measure vessel diameter in addition to blood velocity dynamics. We suggest an algorithm that allows for dynamical masking of a vessel position and measurements of it’s diameter from laser speckle images. This approach demonstrates high reliability and stability.

  7. Development of Automatic 3D Blood Vessel Search and Automatic Blood Sampling System by Using Hybrid Stereo-Autofocus Method

    OpenAIRE

    Eiji Nakamachi; Yusuke Morita; Yoshifumi Mizuno

    2012-01-01

    We developed an accurate three-dimensional blood vessel search (3D BVS) system and an automatic blood sampling system. They were implemented into a point-of-care system designed for medical care, installed in a portable self-monitoring blood glucose (SMBG) device. The system solves problems of human error caused by complicated manual operations of conventional SMBG devices. We evaluated its accuracy of blood-vessel position detection. The 3D BVS system uses near-infrared (NIR) light imaging a...

  8. Computational Fluid Dynamics Analysis of Pulsatile Blood Flow Behavior in Modelled Stenosed Vessels with Different Severities

    OpenAIRE

    Mohsen Mehrabi; Saeed Setayeshi

    2012-01-01

    This study focuses on the behavior of blood flow in the stenosed vessels. Blood is modelled as an incompressible non-Newtonian fluid which is based on the power law viscosity model. A numerical technique based on the finite difference method is developed to simulate the blood flow taking into account the transient periodic behaviour of the blood flow in cardiac cycles. Also, pulsatile blood flow in the stenosed vessel is based on the Womersley model, and fluid flow in the lumen region is gove...

  9. Do Haematophagous Bugs Assess Skin Surface Temperature to Detect Blood Vessels?

    OpenAIRE

    Raquel A Ferreira; Lazzari, Claudio R.; Marcelo G. Lorenzo; Pereira, Marcos H

    2007-01-01

    Background It is known that some blood-sucking insects have the ability to reach vessels under the host skin with their mouthparts to feed blood from inside them. However, the process by which they locate these vessels remains largely unknown. Less than 5% of the skin is occupied by blood vessels and thus, it is not likely that insects rely on a “random search strategy”, since it would increase the probability of being killed by their hosts. Indeed, heterogeneities along the skin surface migh...

  10. Ultrasound sonication with microbubbles disrupts blood vessels and enhances tumor treatments of anticancer nanodrug

    Directory of Open Access Journals (Sweden)

    Lin CY

    2012-04-01

    Full Text Available Chung-Yin Lin1*, Hsiao-Ching Tseng1*, Heng-Ruei Shiu1, Ming-Fang Wu2, Cheng-Ying Chou3, Win-Li Lin1,41Institute of Biomedical Engineering, 2Laboratory Animal Center, 3Department of Bio-Industrial Mechatronics Engineering, National Taiwan University, Taipei, Taiwan; 4Division of Medical Engineering Research, National Health Research Institutes, Miaoli, Taiwan*These authors contributed equally to this workAbstract: Ultrasound (US sonication with microbubbles (MBs has the potential to disrupt blood vessels and enhance the delivery of drugs into the sonicated tissues. In this study, mouse ear tumors were employed to investigate the therapeutic effects of US, MBs, and pegylated liposomal doxorubicin (PLD on tumors. Tumors started to receive treatments when they grew up to about 15 mm3 (early stage with injection of PLD 10 mg/kg, or up to 50 mm3 (medium stage with PLD 6 (or 4 mg/kg. Experiments included the control, PLD alone, PLD + MBs + US, US alone, and MBs + US groups. The procedure for the PLD + MBs + US group was that PLD was injected first, MB (SonoVue injection followed, and then US was immediately sonicated on the tumor. The results showed that: (1 US sonication with MBs was always able to produce a further hindrance to tumor growth for both early and medium-stage tumors; (2 for the medium-stage tumors, 6 mg/kg PLD alone was able to inhibit their growth, while it did not work for 4 mg/kg PLD alone; (3 with the application of MBs + US, 4 mg/kg PLD was able to inhibit the growth of medium-stage tumors; (4 for early stage tumors after the first treatment with a high dose of PLD alone (10 mg/kg, the tumor size still increased for several days and then decreased (a biphasic pattern; (5 MBs + US alone was able to hinder the growth of early stage tumors, but unable to hinder that of medium stage tumors. The results of histological examinations and blood perfusion measurements indicated that the application of MBs + US disrupts the tumor blood

  11. NOK/STYK1 promotes the genesis and remodeling of blood and lymphatic vessels during tumor progression.

    Science.gov (United States)

    Liu, Yue; Li, Tianqi; Hu, Dan; Zhang, Shuping

    2016-09-01

    Previous studies have indicated that the overexpression of NOK, also named STYK1, led to tumorigenesis and metastasis. Here, we provide evidence that increased expression of NOK/STYK1 caused marked alterations in the overall and inner structures of tumors and substantially facilitates the genesis and remodeling of the blood and lymphatic vessels during tumor progression. In particular, NOK-expressed HeLa stable cells (HeLa-K) significantly enhanced tumor growth and metastasis in xenografted nude mice. Hematoxylin and eosin (HE) staining demonstrated that the tumor tissues generated by HeLa-K cells were much more ichorous and had more interspaces than those generated by control HeLa cells (HeLa-C). The fluorescent areas stained with cluster of differentiation 31 (CD31), a marker protein for blood vessels, appeared to be in different patterns. The total blood vessels, especially the ring patterns, within the tumors of the HeLa-K group were highly enriched compared with those in the HeLa-C group. NOK-HA was demonstrated to be well colocalized with CD31 in the wall of the tubular structures within tumor tissues. Interestingly, antibody staining of the lymphatic vessel endothelial hyaluronan receptor (LYVE-1) further revealed the increase in ring (oratretic strip-like) lymphatic vessels in either the peritumoral or intratumoral areas in the HeLa-K group compared with the HeLa-C group. Consistently, the analysis of human cancerous tissue also showed that NOK was highly expressed in the walls of tubular structures. Thus, our results reveal a novel tumorigenic function of NOK to mediate the genesis and remodeling of blood and lymphatic vessels during tumor progression. PMID:27444381

  12. ENHANCED ABSORPTION OF MILLIMETER WAVE ENERGY IN MURINE SUBCUTANEOUS BLOOD VESSELS

    OpenAIRE

    Alekseev, Stanislav I.; Ziskin, Marvin C.

    2011-01-01

    The aim of the present study was to determine millimeter wave (MMW) absorption by blood vessels traversing the subcutaneous fat layer of murine skin. Most calculations were performed using the finite-difference time-domain (FDTD) technique. We used two types of models: (1) a rectangular block of multilayer tissue with blood vessels traversing the fat layer and (2) cylindrical models with circular and elliptical cross sections simulating the real geometry of murine limbs. We found that the spe...

  13. Assessing the quality of angiographic display of brain blood vessels aneurysms compared to intraoperative state

    OpenAIRE

    Nikolić Igor M.; Tasić Goran M.; Jovanović Vladimir T.; Repac Nikola R.; Janićijević Aleksandar M.; Šćepanović Vuk D.; Nestorović Branislav D.

    2013-01-01

    Background/Aim. Aneurysms in brain blood vessels are expanding bags composed of a neck, body and fundus. Clear visibility of the neck, the position of the aneurysm and surrounding structures are necessary for a proper choice of methods for excluding the aneurysm from the circulation. The aim of this study was to evaluate the reliability of spatial reconstruction of blood vessels of the brain based on the original software for 3D reconstruction of the equipment manufacturer and a persona...

  14. Detection of retinal blood vessel changes in multiple sclerosis with optical coherence tomography

    OpenAIRE

    Bhaduri, Basanta; Nolan, Ryan M.; Shelton, Ryan L.; Pilutti, Lara A.; Motl, Robert W.; Moss, Heather E.; Pula, John H.; Boppart, Stephen A.

    2016-01-01

    Although retinal vasculitis is common in multiple sclerosis (MS), it is not known if MS is associated with quantitative abnormalities in retinal blood vessels (BVs). Optical coherence tomography (OCT) is suitable for examining the integrity of the anterior visual pathways in MS. In this paper we have compared the size and number of retinal blood vessels in patients with MS, with and without a history of optic neuritis (ON), and control subjects from the cross-sectional retinal images from OCT...

  15. Visualisation of blood and lymphatic vessels with increasing exposure time of the detector

    Energy Technology Data Exchange (ETDEWEB)

    Kalchenko, V V; Kuznetsov, Yu L; Meglinski, I V

    2013-07-31

    We describe the laser speckle contrast method for simultaneous noninvasive imaging of blood and lymphatic vessels of living organisms, based on increasing detector exposure time. In contrast to standard methods of fluorescent angiography, this technique of vascular bed imaging and lymphatic and blood vessel demarcation does not employ toxic fluorescent markers. The method is particularly promising with respect to the physiology of the cardiovascular system under in vivo conditions. (laser applications in biology and medicine)

  16. Trigeminal origin or B-preprotachykinin products in feline pial blood vessels

    International Nuclear Information System (INIS)

    A specific and sensitive radioimmunoassay measured the presence of immunoreactive neurokinin A within feline and human pial arteries. Immunoreactivity exhibited a retention time identical to that of synthetic peptide when acid extracts from feline and human blood vessels were subjected to reverse-phase high-performance liquid chromatography. As shown previously for substance P, levels of immunoreactive neurokinin A decreased significantly in the vessels from the ipsilateral rostral circle of Willis l9-24 days following unilateral trigeminal ganglionectomy. Hence, trigeminal projections to cerebral blood vessels contain both products of B-preprotachykinin mRNA. (author)

  17. Application of the Carreau viscosity model to the oscillatory flow in blood vessels

    Science.gov (United States)

    Tabakova, Sonia; Kutev, Nikolay; Radev, Stefan

    2015-11-01

    When studying the oscillatory flow in different types of blood vessels it is very important to know what type of the blood viscosity model has to be used. In general the blood viscosity is defined as a shear-thinning liquid, for which there exist different shear-dependent models, for example the Carreau model, which represents the viscosity as a non-linear function of the shear-rate. In some cases, however, the blood viscosity could be regarded as constant, i.e., the blood is treated as Newtonian fluid. The aim of the present work is to show theoretically and numerically some approximate limits of the Newtonian model application, when the blood vessel is assumed as a 2D straight tube. The obtained results are in agreement with other authors' numerical results based on similar blood viscosity models.

  18. Vascular bursts enhance permeability of tumour blood vessels and improve nanoparticle delivery

    Science.gov (United States)

    Matsumoto, Yu; Nichols, Joseph W.; Toh, Kazuko; Nomoto, Takahiro; Cabral, Horacio; Miura, Yutaka; Christie, R. James; Yamada, Naoki; Ogura, Tadayoshi; Kano, Mitsunobu R.; Matsumura, Yasuhiro; Nishiyama, Nobuhiro; Yamasoba, Tatsuya; Bae, You Han; Kataoka, Kazunori

    2016-06-01

    Enhanced permeability in tumours is thought to result from malformed vascular walls with leaky cell-to-cell junctions. This assertion is backed by studies using electron microscopy and polymer casts that show incomplete pericyte coverage of tumour vessels and the presence of intercellular gaps. However, this gives the impression that tumour permeability is static amid a chaotic tumour environment. Using intravital confocal laser scanning microscopy we show that the permeability of tumour blood vessels includes a dynamic phenomenon characterized by vascular bursts followed by brief vigorous outward flow of fluid (named ‘eruptions’) into the tumour interstitial space. We propose that ‘dynamic vents’ form transient openings and closings at these leaky blood vessels. These stochastic eruptions may explain the enhanced extravasation of nanoparticles from the tumour blood vessels, and offer insights into the underlying distribution patterns of an administered drug.

  19. Evaluation of immunohistochemical markers of lymphatic and blood vessels in canine mammary tumours.

    Science.gov (United States)

    Sleeckx, N; Van Brantegem, L; Fransen, E; Van den Eynden, G; Casteleyn, C; Veldhuis Kroeze, E; Van Ginneken, C

    2013-05-01

    Canine mammary tumours (CMTs) are the most common neoplasms in intact female dogs. Bitches with spontaneously arising CMTs represent a promising animal model for human breast cancer research. The aim of the present study was to develop an immunohistochemical protocol for the identification of blood and lymphatic vessels in CMTs. Antibodies specific for human lymphatic vessels (prox-1, lyve-1, podoplanin and D2-40) and blood vessels (von Willebrand factor [vWf], CD31 and CD34) were utilized. Serial sections of 18 samples (eight samples of normal canine mammary tissue, five benign and five malignant CMTs) were examined. Antibodies specific for podoplanin, D2-40 and CD34 showed no immunoreactivity with canine tissue. Prox-1 and CD31 were determined to be the most suitable markers for lymphatic and blood vessels, respectively. PMID:23123127

  20. Computational Fluid Dynamics Analysis of Pulsatile Blood Flow Behavior in Modelled Stenosed Vessels with Different Severities

    Directory of Open Access Journals (Sweden)

    Mohsen Mehrabi

    2012-01-01

    Full Text Available This study focuses on the behavior of blood flow in the stenosed vessels. Blood is modelled as an incompressible non-Newtonian fluid which is based on the power law viscosity model. A numerical technique based on the finite difference method is developed to simulate the blood flow taking into account the transient periodic behaviour of the blood flow in cardiac cycles. Also, pulsatile blood flow in the stenosed vessel is based on the Womersley model, and fluid flow in the lumen region is governed by the continuity equation and the Navier-Stokes equations. In this study, the stenosis shape is cosine by using Tu and Devil model. Comparing the results obtained from three stenosed vessels with 30%, 50%, and 75% area severity, we find that higher percent-area severity of stenosis leads to higher extrapressure jumps and higher blood speeds around the stenosis site. Also, we observe that the size of the stenosis in stenosed vessels does influence the blood flow. A little change on the cross-sectional value makes vast change on the blood flow rate. This simulation helps the people working in the field of physiological fluid dynamics as well as the medical practitioners.

  1. Tracing retinal blood vessels by matrix-forest theorem of directed graphs.

    Science.gov (United States)

    Cheng, Li; De, Jaydeep; Zhang, Xiaowei; Lin, Feng; Li, Huiqi

    2014-01-01

    This paper aims to trace retinal blood vessel trees in fundus images. This task is far from being trivial as the crossover of vessels are commonly encountered in image-based vessel networks. Meanwhile it is often crucial to separate the vessel tree structures in applications such as diabetic retinopathy analysis. In this work, a novel directed graph based approach is proposed to cast the task as label propagation over directed graphs, such that the graph is to be partitioned into disjoint sub-graphs, or equivalently, each of the vessel trees is traced and separated from the rest of the vessel network. Then the tracing problem is addressed by making novel usage of the matrix-forest theorem in algebraic graph theory. Empirical experiments on synthetic as well as publicly available fundus image datasets demonstrate the applicability of our approach. PMID:25333171

  2. HIFU procedures at moderate intensities-effect of large blood vessels

    International Nuclear Information System (INIS)

    A three-dimensional computational model is presented for studying the efficacy of high-intensity focused ultrasound (HIFU) procedures targeted near large blood vessels. The analysis applies to procedures performed at intensities below the threshold for cavitation, boiling and highly nonlinear propagation, but high enough to increase tissue temperature a few degrees per second. The model is based upon the linearized KZK equation and the bioheat equation in tissue. In the blood vessel the momentum and energy equations are satisfied. The model is first validated in a tissue phantom, to verify the absence of bubble formation and nonlinear effects. Temperature rise and lesion-volume calculations are then shown for different beam locations and orientations relative to a large vessel. Both single and multiple ablations are considered. Results show that when the vessel is located within about a beam width (few mm) of the ultrasound beam, significant reduction in lesion volume is observed due to blood flow. However, for gaps larger than a beam width, blood flow has no major effect on the lesion formation. Under the clinically representative conditions considered, the lesion volume is reduced about 40% (relative to the no-flow case) when the beam is parallel to the blood vessel, compared to about 20% for a perpendicular orientation. Procedures involving multiple ablation sites are affected less by blood flow than single ablations. The model also suggests that optimally focused transducers can generate lesions that are significantly larger (>2 times) than the ones produced by highly focused beams

  3. HIFU procedures at moderate intensities-effect of large blood vessels

    Energy Technology Data Exchange (ETDEWEB)

    Hariharan, P [Mechanical, Industrial, and Nuclear Engineering Department, University of Cincinnati, Cincinnati, OH (United States); Myers, M R [Division of Solid and Fluid Mechanics, Center for Devices and Radiological Health, US Food and Drug Administration, 10903 New Hampshire Avenue, Building 62, Silver Spring, MD 20993-0002 (United States); Banerjee, R K [Mechanical, Industrial, and Nuclear Engineering Department, University of Cincinnati, Cincinnati, OH (United States)

    2007-07-21

    A three-dimensional computational model is presented for studying the efficacy of high-intensity focused ultrasound (HIFU) procedures targeted near large blood vessels. The analysis applies to procedures performed at intensities below the threshold for cavitation, boiling and highly nonlinear propagation, but high enough to increase tissue temperature a few degrees per second. The model is based upon the linearized KZK equation and the bioheat equation in tissue. In the blood vessel the momentum and energy equations are satisfied. The model is first validated in a tissue phantom, to verify the absence of bubble formation and nonlinear effects. Temperature rise and lesion-volume calculations are then shown for different beam locations and orientations relative to a large vessel. Both single and multiple ablations are considered. Results show that when the vessel is located within about a beam width (few mm) of the ultrasound beam, significant reduction in lesion volume is observed due to blood flow. However, for gaps larger than a beam width, blood flow has no major effect on the lesion formation. Under the clinically representative conditions considered, the lesion volume is reduced about 40% (relative to the no-flow case) when the beam is parallel to the blood vessel, compared to about 20% for a perpendicular orientation. Procedures involving multiple ablation sites are affected less by blood flow than single ablations. The model also suggests that optimally focused transducers can generate lesions that are significantly larger (>2 times) than the ones produced by highly focused beams.

  4. HIFU procedures at moderate intensities--effect of large blood vessels.

    Science.gov (United States)

    Hariharan, P; Myers, M R; Banerjee, R K

    2007-06-21

    A three-dimensional computational model is presented for studying the efficacy of high-intensity focused ultrasound (HIFU) procedures targeted near large blood vessels. The analysis applies to procedures performed at intensities below the threshold for cavitation, boiling and highly nonlinear propagation, but high enough to increase tissue temperature a few degrees per second. The model is based upon the linearized KZK equation and the bioheat equation in tissue. In the blood vessel the momentum and energy equations are satisfied. The model is first validated in a tissue phantom, to verify the absence of bubble formation and nonlinear effects. Temperature rise and lesion-volume calculations are then shown for different beam locations and orientations relative to a large vessel. Both single and multiple ablations are considered. Results show that when the vessel is located within about a beam width (few mm) of the ultrasound beam, significant reduction in lesion volume is observed due to blood flow. However, for gaps larger than a beam width, blood flow has no major effect on the lesion formation. Under the clinically representative conditions considered, the lesion volume is reduced about 40% (relative to the no-flow case) when the beam is parallel to the blood vessel, compared to about 20% for a perpendicular orientation. Procedures involving multiple ablation sites are affected less by blood flow than single ablations. The model also suggests that optimally focused transducers can generate lesions that are significantly larger (>2 times) than the ones produced by highly focused beams. PMID:17664556

  5. An experimental system for the study of ultrasound exposure of isolated blood vessels

    International Nuclear Information System (INIS)

    An experimental system designed for the study of the effects of diagnostic or therapeutic ultrasound exposure on isolated blood vessels in the presence or absence of intraluminal contrast agent is described. The system comprised several components. A microscope was used to monitor vessel size (and thus vessel functionality), and potential leakage of intraluminal 70 kDa FITC-dextran fluorescence marker. A vessel chamber allowed the mounting of an isolated vessel whilst maintaining its viability, with pressure regulation for the control of intraluminal pressure and induction of flow for the infusion of contrast microbubbles. A fibre-optic hydrophone sensor mounted on the vessel chamber using a micromanipulator allowed pre-exposure targeting of the vessel to within 150 µm, and monitoring of acoustic cavitation emissions during exposures. Acoustic cavitation was also detected using changes in the ultrasound drive voltage and by detection of audible emissions using a submerged microphone. The suitability of this system for studying effects in the isolated vessel model has been demonstrated using a pilot study of 6 sham exposed and 18 high intensity focused ultrasound exposed vessels, with or without intraluminal contrast agent (SonoVue) within the vessels. (paper)

  6. Blood vessel extraction and optic disc removal using curvelet transform and kernel fuzzy c-means.

    Science.gov (United States)

    Kar, Sudeshna Sil; Maity, Santi P

    2016-03-01

    This paper proposes an automatic blood vessel extraction method on retinal images using matched filtering in an integrated system design platform that involves curvelet transform and kernel based fuzzy c-means. Since curvelet transform represents the lines, the edges and the curvatures very well and in compact form (by less number of coefficients) compared to other multi-resolution techniques, this paper uses curvelet transform for enhancement of the retinal vasculature. Matched filtering is then used to intensify the blood vessels' response which is further employed by kernel based fuzzy c-means algorithm that extracts the vessel silhouette from the background through non-linear mapping. For pathological images, in addition to matched filtering, Laplacian of Gaussian filter is also employed to distinguish the step and the ramp like signal from that of vessel structure. To test the efficacy of the proposed method, the algorithm has also been applied to images in presence of additive white Gaussian noise where the curvelet transform has been used for image denoising. Performance is evaluated on publicly available DRIVE, STARE and DIARETDB1 databases and is compared with the large number of existing blood vessel extraction methodologies. Simulation results demonstrate that the proposed method is very much efficient in detecting the long and the thick as well as the short and the thin vessels with an average accuracy of 96.16% for the DRIVE and 97.35% for the STARE database wherein the existing methods fail to extract the tiny and the thin vessels. PMID:26848729

  7. Prevent Diabetes Problems: Keep Your Heart and Blood Vessels Healthy

    Science.gov (United States)

    ... Research Training & Career Development Grant programs for students, postdocs, and faculty Research at NIDDK Labs, faculty, and ... Top ] What can I do to prevent or control PAD? Don't smoke. Keep blood glucose and ...

  8. Prevent Diabetes Problems: Keep Your Heart and Blood Vessels Healthy

    Science.gov (United States)

    ... Association of Diabetes Educators Academy of Nutrition and Dietetics National Heart Lung and Blood Institute American Diabetes ... for Scientists Current Funding Opportunities Funded Grants & Grant History Funding Process Research Programs & Contacts Research Training & Career ...

  9. Aging changes in the heart and blood vessels

    Science.gov (United States)

    ... Some of the things that make your heart work harder are: Certain medicines Emotional stress Physical exertion Illness Infections Injuries COMMON PROBLEMS Angina (chest pain caused by temporarily reduced blood flow to the ...

  10. Triamcinolone Acetonide Selectively Inhibits Angiogenesis in Small Blood Vessels and Decreases Vessel Diameter within the Vascular Tree

    Science.gov (United States)

    McKay, Terri L.; Gredeon, Dan J.; Vickerman, Mary B.; Hylton, alan G.; Ribita, Daniela; Olar, Harry H.; Kaiser, Peter K.; Parsons-Wingerter, Patricia

    2007-01-01

    The steroid triamcinolone acetonide (TA) is a potent anti-angiogenesis drug used to treat retinal vascular diseases that include diabetic retinopathy, vascular occlusions and choroidal neovascularization. To quantify the effects of TA on branching morphology within the angiogenic microvascular tree of the chorioallantoic membrane (CAM) of quail embryos. Increasing concentrations of TA (0-16 ng/ml) were applied topically on embryonic day 7 (E7) to the chorioallantoic membrane (CAM) of quail embryos cultured in Petri dishes, and incubated for an additional 24 or 48 hours until fixation. Binary (black/white) microscopic images of arterial end points were quantified by VESGEN software (for Generational Analysis of Vessel Branching) to obtain major vascular parameters that include vessel diameter (Dv), fractal dimension (Df), tortuosity (Tv) and densities of vessel area, length, number and branch point (Av, Lv, Nv and Brv). For assessment of specific changes in vascular morphology induced by TA, the VESGEN software automatically segmented the vascular tree into branching generations (G1...G10) according to changes in vessel diameter and branching. Vessel density decreased significantly up to 34% as the function of increasing concentration of TA according to Av, Lv, Brv, Nv and Df. TA selectively inhibited the growth of new, small vessels, because Lv decreased from 13.14plus or minus 0.61 cm/cm2 for controls to 8.012 plus or minus 0.82 cm/cm2 at 16 ng TA/ml in smaller branching generations (G7-G10), and for Nv from 473.83 plus or minus 29.85 cm(-)2 to 302.32 plus or minus 33.09 cm-()2. In contrast, vessel diameter (Dv) decreased throughout the vascular tree (G1-G10).

  11. Blood porphyrin luminescence and tumor growth correlation

    Science.gov (United States)

    Courrol, Lilia Coronato; Silva, Flávia Rodrigues de Oliveira; Bellini, Maria Helena; Mansano, Ronaldo Domingues; Schor, Nestor; Vieira, Nilson Dias, Jr.

    2007-02-01

    Fluorescence technique appears very important for the diagnosis of cancer. Fluorescence detection has advantages over other light-based investigation methods: high sensitivity, high speed, and safety. Renal cell carcinoma (RCC) accounts for approximately 3% of new cancer incidence and mortality in the United States. Unfortunately many RCC masses remain asymptomatic and nonpalpable until they are advanced. Diagnosis and localization of early carcinoma play an important role in the prevention and curative treatment of RCC. Certain drugs or chemicals such as porphyrin derivatives accumulate substantially more in tumors than normal tissues. The autofluorescence of blood porphyrin of healthy and tumor induced male SCID mice was analyzed using fluorescence and excitation spectroscopy. A significant contrast between normal and tumor blood could be established. Blood porphyrin fluorophore showed enhanced fluorescence band (around 630 nm) in function of the tumor growth. This indicates that either the autofluorescence intensity of the blood fluorescence may provide a good parameter for the "first approximation" characterization of the tumor stage.

  12. 血管内皮生长因子和雌二醇促进血管内皮祖细胞分化生成血管的对比研究%Comparative study of vascular endothelial growth factor and estradiol in promoting endothelial progenitor cells differentiation and generation blood vessels

    Institute of Scientific and Technical Information of China (English)

    董勇; 李文志; 辛毅; 孙智

    2013-01-01

    Objective To compare the ability of vascular endothelial growth factor (VEGF) and estradiol in promoting endothelial progenitor cells differentiation and generation blood vessels under common doses. Methods To isolate and culture human peripheral blood EPCs first, then to mixe with the matrigel and transplante to the lower abdomens of nine nude mice.to divide the nine nude mice into three groups according to a random grouping, to inject VEGF.estradiol and saline at a regular time,to observe and record the growing status of vascular tissue regularly.to draw the vascular tissue after six weeks, to observe the organizational structure by HE staining, then contrast with the groups. Results The vascular tissue volume groups injected of drugs have significant difference with the groups injected of saline.they have bigger volume to contrast the groups injected of saline, but he vascular tissue volume between the groups injected of drugs is no significant difference. By drawning HE staining, the vascular tissues have proliferational mussy blood vessels.The vascular density of the groups injected of drugs is significantly greater than the groups injected of saline, but he vascular density between the groups injected of drugs is small. Conclusion VEGF and estradiol can promote EPCs differentiation and generation blood vessels.their respective promoting EPCs differentiation and generation blood vessels potency is no significant difference under common doses.%目的:对比研究常规剂量下血管内皮生长因子(VEGF)和雌二醇对血管内皮祖细胞(EPCs)分化生成血管的促进作用.方法:分离培养人外周血EPCs,与基质胶混匀后注射到9只裸鼠双侧下腹部,另设2只注射等体积培养液与基质胶的混合液.将9只注射细胞的裸鼠随机分为3组,每组分别定期局部注射VEGF、雌二醇,生理盐水,定期观察记录血管组织块的生长状况.移植6周后取材,测量计算血管组织块的体积、HE染色观察血管

  13. Primo Vascular System Accompanying a Blood Vessel from Tumor Tissue and a Method to Distinguish It from the Blood or the Lymph System

    OpenAIRE

    Jaekwan Lim; Sungwoo Lee; Zhendong Su; Hong Bae Kim; Jung Sun Yoo; Kwang-Sup Soh; Sungchul Kim; Yeon Hee Ryu

    2013-01-01

    A primo vessel was observed in the abdominal cavity in the lung cancer mouse model, and its function as an extra metastatic path was observed. In this work, we found a primo vessel accompanying a blood vessel emanating from a tumor in the skin. We also presented simple and efficient criteria to distinguish a primo vessel from a blood or a lymph vessel and from a nerve. The criteria for using DAPI and Phalloidin will be useful in clinical situations to find and identify the primo vessels among...

  14. Coupled modeling of tumour angiogenesis, tumour growth,and blood perfusion

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    This paper proposes a more realistic mathematical simulation method to investigate the dynamic process of tumour angio-genesis by fully coupling the vessel growth,tumour growth and associated blood perfusion.The tumour growth and angiogenesis are coupled by the chemical microenvironment and the cell-matrix interaction.The haemodynamic calculation is carried out on the new vasculature,and an estimation of vessel collapse is made according to the wall shear stress criterion.The results are consistent with phy...

  15. Collagen-based scaffolds for tissue engineering of small-diameter blood vessels

    OpenAIRE

    Buttafoco, Laura

    2005-01-01

    Atherosclerotic vascular disease, including peripheral and coronary artery disease, is the main cause of morbidity and mortality in the Western society. Although synthetic blood vessel prostheses are successfully being used for large-diameter vascular reconstructions, until now no functional small-diameter (< 6 mm) artificial vascular graft is available. Autologous veins and arteries are currently being used as vessel substitutes, but limitations in arteries supply and compliance mismatch are...

  16. Aging changes in the heart and blood vessels

    Science.gov (United States)

    ... for treating high blood pressure, high cholesterol or diabetes. Reduce or stop smoking. Men between the ages of 65 to 75 who have ever smoked should be screened for aneurysms in their abdominal aorta. Get more exercise: Exercise may help prevent obesity, ...

  17. The efficiency of laser radiation absorption by hemoglobin and oxyhemoglobin in the skin blood vessels

    International Nuclear Information System (INIS)

    The results of the investigation of the efficiency of light absorption by oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb) in cutaneous blood vessels in dependence on the radiation wavelength and the optical properties of the tissue is presented. Using the Kubelka - Munk optical model of the tissue the spectral dependence of the efficiency of laser interaction both on HbO2 and Hb of blood vessels at different depths of the tissue layer are calculated. The obtained results show that for blood vessels located in tissue up to a depth of 2500 μm the efficiency of laser radiation absorption follows the shape of the Q -absorption bands of HbO2 and Hb

  18. Tissue-Engineered Blood Vessels in Pediatric Cardiac Surgery

    OpenAIRE

    Shinoka, Toshiharu; Breuer, Christopher

    2008-01-01

    Pediatric cardiovascular surgeons often encounter patients requiring surgical intervention utilizing foreign materials to repair complex lesions. However, the materials that are commonly used lack growth potential, and long-term results have revealed several material-related failures, such as stenosis, thromboembolization, calcium deposition, and risk of infection. To solve these problems, in particular for children who require the implantation of dynamic material with growth potential, we so...

  19. Mathematical modelling for trajectories of magnetic nanoparticles in a blood vessel under magnetic field

    International Nuclear Information System (INIS)

    A mathematical model is developed to describe the trajectories of a cluster of magnetic nanoparticles in a blood vessel for the application of magnetic drug targeting (MDT). The magnetic nanoparticles are injected into a blood vessel upstream from a malignant tissue and are captured at the tumour site with help of an applied magnetic field. The applied field is produced by a rare earth cylindrical magnet positioned outside the body. All forces expected to significantly affect the transport of nanoparticles were incorporated, including magnetization force, drag force and buoyancy force. The results show that particles are slow down and captured under the influence of magnetic force, which is responsible to attract the magnetic particles towards the magnet. It is optimized that all particles are captured either before or at the centre of the magnet (z≤0) when blood vessel is very close proximity to the magnet (d=2.5 cm). However, as the distance between blood vessel and magnet (d) increases (above 4.5 cm), the magnetic nanoparticles particles become free and they flow away down the blood vessel. Further, the present model results are validated by the simulations performed using the finite element based COMSOL software. - Highlights: • A mathematical model is developed to describe the trajectories of magnetic nanoparticles. • The dominant magnetic, drag and buoyancy forces are considered. • All particles are captured when distance between blood vessel and magnet (d) is up to 4.5 cm. • Further increase in d value (above 4.5 cm) results the free movement of magnetic particles

  20. Do haematophagous bugs assess skin surface temperature to detect blood vessels?

    Directory of Open Access Journals (Sweden)

    Raquel A Ferreira

    Full Text Available BACKGROUND: It is known that some blood-sucking insects have the ability to reach vessels under the host skin with their mouthparts to feed blood from inside them. However, the process by which they locate these vessels remains largely unknown. Less than 5% of the skin is occupied by blood vessels and thus, it is not likely that insects rely on a "random search strategy", since it would increase the probability of being killed by their hosts. Indeed, heterogeneities along the skin surface might offer exploitable information for guiding insect's bites. METHODOLOGY/PRINCIPAL FINDINGS: We tested whether the bug Rhodnius prolixus can evaluate temperature discontinuities along the body surface in order to locate vessels before piercing the host skin. When placed over a rabbit ear, the bug's first bites were mostly directed towards the main vessels. When insects were confronted to artificial linear heat sources presenting a temperature gradient against the background, most bites were directly addressed to the warmer linear source, notwithstanding the temperature of both, the source and the background. Finally, tests performed using uni- and bilaterally antennectomized insects revealed that the bilateral integration of thermal inputs from both antennae is necessary for precisely directing bites. CONCLUSIONS/SIGNIFICANCE: R. prolixus may be able to exploit the temperature differences observed over the skin surface to locate blood vessles. Bugs bite the warmest targets regardless of the target/background temperatures, suggesting that they do not bite choosing a preferred temperature, but select temperature discontinuities along the skin. This strategy seems to be an efficient one for finding blood vessels within a wide temperature range, allowing finding them on different hosts, as well as on different areas of the host body. Our study also adds new insight about the use of antennal thermal inputs by blood sucking bugs.

  1. Mathematical modelling for trajectories of magnetic nanoparticles in a blood vessel under magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Shashi, E-mail: shashisharma1984@gmail.com; Katiyar, V.K.; Singh, Uaday

    2015-04-01

    A mathematical model is developed to describe the trajectories of a cluster of magnetic nanoparticles in a blood vessel for the application of magnetic drug targeting (MDT). The magnetic nanoparticles are injected into a blood vessel upstream from a malignant tissue and are captured at the tumour site with help of an applied magnetic field. The applied field is produced by a rare earth cylindrical magnet positioned outside the body. All forces expected to significantly affect the transport of nanoparticles were incorporated, including magnetization force, drag force and buoyancy force. The results show that particles are slow down and captured under the influence of magnetic force, which is responsible to attract the magnetic particles towards the magnet. It is optimized that all particles are captured either before or at the centre of the magnet (z≤0) when blood vessel is very close proximity to the magnet (d=2.5 cm). However, as the distance between blood vessel and magnet (d) increases (above 4.5 cm), the magnetic nanoparticles particles become free and they flow away down the blood vessel. Further, the present model results are validated by the simulations performed using the finite element based COMSOL software. - Highlights: • A mathematical model is developed to describe the trajectories of magnetic nanoparticles. • The dominant magnetic, drag and buoyancy forces are considered. • All particles are captured when distance between blood vessel and magnet (d) is up to 4.5 cm. • Further increase in d value (above 4.5 cm) results the free movement of magnetic particles.

  2. Transient Non-Newtonian Blood Flow under Magnetic Targeting Drug Delivery in an Aneurysm Blood Vessel with Porous Walls

    Science.gov (United States)

    Alimohamadi, Haleh; Imani, Mohsen

    2014-11-01

    The present investigation deals with numerical solution of blood flow patterns through an aneurysm artery under the applied magnetic field. Transient extended Navier-Stokes, Brinkman, continuity, and heat conduction equations govern this phenomenon and unsteady pulsatile inlet velocity varies by human heart-beating frequency. Our simulation demonstrates applying 105 magnetic field intensity (MnF) to recirculate flow and increase fluid flux and maximum blood temperature by 62.5x and 3.5%, respectively, in the aneurysm region. It is also shown that the vessel's wall porosity plays an important role in magnetic targeting of drug delivery performance, as this parameter can noticeably change maximum blood temperature and pressure.

  3. Inclusion body myositis, muscle blood vessel and cardiac amyloidosis, and transthyretin Val122Ile allele.

    Science.gov (United States)

    Askanas, V; Engel, W K; Alvarez, R B; Frangione, B; Ghiso, J; Vidal, R

    2000-04-01

    Typical of sporadic inclusion body myositis muscle biopsies are vacuolated muscle fibers containing intracellular amyloid deposits and accumulations of "Alzheimer-characteristic" proteins. There is no muscle blood vessel or cardiac amyloidosis. We report on a 70-year-old African-American man homozygous for the transthyretin Val122Ile allele who has both sporadic inclusion body myositis and cardiac amyloidosis. His unique pathological features included transthyretin immunoreactivity in prominent muscle blood vessel amyloid and congophilic amyloid deposits within vacuolated muscle fibers. PMID:10762172

  4. Negative Pressure Wound Therapy - Mechanisms of Action and Protecting Exposed Blood Vessels in the Wound Bed

    OpenAIRE

    Anesäter, Erik

    2015-01-01

    NPWT has recently been associated with severe complications and bleeding when used in wounds with exposed blood vessels. The aims of this work were to investigate the mechanisms of action of NPWT and to explore the possibility of using thin plastic discs to protect exposed blood vessels in the wound bed during NPWT. Three different kinds of wounds were created in pigs: 6 cm and 10 cm diameter circular defect wounds on the back and 6 cm incision wounds in the groin, exposing the...

  5. How to explore the effects of sex hormone on blood vessels

    Institute of Scientific and Technical Information of China (English)

    Sun Mei-li; Nie Min; Liu Bing; Du Zhi-jun; Ge Qin-sheng

    2004-01-01

    The risk of cardiovascular disease increases along with aging. There are increasing interests in researches on the protective effects of hormone replacement therapy (HRT)on cardiovascular system in postmenopausal women. In this article we will review how we have explored the evidence of different sex hormones on blood vessels since 1996. The results showed that low-dose HRT significantly protected cardiovascular system in postmenopausal women.However, the high-dose 17β-estradiol (E2), with or without progesterone (P) or testosterone (T), or any hormone alone, as their concentrations increase, may even inhibit the protective effects of low-dose HRT on blood vessels.

  6. Effect of Rolling Massage on the Vortex Flow in Blood Vessels with Lattice Boltzmann Simulation

    Science.gov (United States)

    Yi, Hou Hui

    The rolling massage manipulation is a classic Chinese Medical Massage, which is a nature therapy in eliminating many diseases. Here, the effect of the rolling massage on the cavity flows in blood vessel under the rolling manipulation is studied by the lattice Boltzmann simulation. The simulation results show that the vortex flows are fully disturbed by the rolling massage. The flow behavior depends on the rolling velocity and the rolling depth. Rolling massage has a better effect on the flows in the cavity than that of the flows in a planar blood vessel. The result is helpful to understand the mechanism of the massage and develop the rolling techniques.

  7. Microscopic examination of crack growth in a pressure vessel steel

    International Nuclear Information System (INIS)

    A fairly systematic microscopic study concerning ductile and ductile-brittle crack growth in the A508B pressure vessel steel has been performed. The main method of investigation was to subject fracture mechanics specimens (sub-sized three point bend specimens) to predetermined load levels corresponding to different amounts of ductile crack extension. The specimens were then cut perpendicularly to the plane of the crack and the area in front of the crack was examined in a SEM. The object of these examinations was to determine if newly encountered computational results could be correlated to crack extension characteristics and to study whether the mechanism of ductile growth was of the void growth type or of the fast shear mechanism. This is important for further numerical modelling of the process. Both the original material and a specially heat treated piece were investigated. The heat treatment was performed in order to raise the transition temperature to about 60 deg C with the object to provide a more convenient testing situation. Charpy V tests were performed for the specially heat treated material to obtain the temperature dependence of the toughness. This was also studied by performing fracture toughness determination on the same type of specimens as were used for the microscopic study. The heat treatment used fulfilled the above purpose and the microscopic studies provide a good understanding of the micro mechanisms operating in the ductile fracture process for this material

  8. Postmortem computed tomography with the use of air for blood vessel enhancement-Early experience.

    Science.gov (United States)

    Borowska-Solonynko, Aleksandra; Solonynko, Bohdan; Fudalej, Marcin; Żyłkowski, Jarosław

    2016-04-01

    Postmortem computed tomography (PMCT) is gaining popularity in forensic medicine. Computed tomography routinely performed in clinical medicine involves intravenous contrast administration. Unfortunately, postmortem examinations are typically limited to uncontrasted CT scans, where blood vessels and their potential injury sites are invisible. One serious problem is the fact that due to the process of decomposition, contrast agents used for vessel visualization in the living cannot be used in cadavers. Therefore, a special contrast agent designed for cadavers has been developed. This contrast agent has a high density and is lipophilic. Its use ensures very good visualization of blood vessels it is, however, associated with high costs and may alter findings of a later histopathological examination. This study presents early experience with the air as negative contrast agent to enhance all blood vessels in the body. The carbon dioxide (CO2) gas has been used as a contrast agent in live individuals with contraindications against the use of iodinated contrast. In corpses with advanced postmortem changes, putrefaction gases also considerably enhance the visibility of blood vessels and organs they fill. There have also been some positive effects with the use of gas in postmortem angiography of coronary vessels. These findings encouraged us to attempt air administration via catheters introduced into the femoral artery or a central venous access site in the superior vena cava. The gas distributed easily throughout the body and surprisingly well contrasted both arteries and veins of various caliber. The presence of the air administered into vessels did not cause any apparent, significant alterations in autopsy findings. Although optimization of the gas administration technique requires further studies, we can already say that this is a promising direction in postmortem angiography. PMID:26921814

  9. Mouse lung contains endothelial progenitors with high capacity to form blood and lymphatic vessels

    Directory of Open Access Journals (Sweden)

    Barleon Bernhard

    2010-07-01

    Full Text Available Abstract Background Postnatal endothelial progenitor cells (EPCs have been successfully isolated from whole bone marrow, blood and the walls of conduit vessels. They can, therefore, be classified into circulating and resident progenitor cells. The differentiation capacity of resident lung endothelial progenitor cells from mouse has not been evaluated. Results In an attempt to isolate differentiated mature endothelial cells from mouse lung we found that the lung contains EPCs with a high vasculogenic capacity and capability of de novo vasculogenesis for blood and lymph vessels. Mouse lung microvascular endothelial cells (MLMVECs were isolated by selection of CD31+ cells. Whereas the majority of the CD31+ cells did not divide, some scattered cells started to proliferate giving rise to large colonies (> 3000 cells/colony. These highly dividing cells possess the capacity to integrate into various types of vessels including blood and lymph vessels unveiling the existence of local microvascular endothelial progenitor cells (LMEPCs in adult mouse lung. EPCs could be amplified > passage 30 and still expressed panendothelial markers as well as the progenitor cell antigens, but not antigens for immune cells and hematopoietic stem cells. A high percentage of these cells are also positive for Lyve1, Prox1, podoplanin and VEGFR-3 indicating that a considerabe fraction of the cells are committed to develop lymphatic endothelium. Clonogenic highly proliferating cells from limiting dilution assays were also bipotent. Combined in vitro and in vivo spheroid and matrigel assays revealed that these EPCs exhibit vasculogenic capacity by forming functional blood and lymph vessels. Conclusion The lung contains large numbers of EPCs that display commitment for both types of vessels, suggesting that lung blood and lymphatic endothelial cells are derived from a single progenitor cell.

  10. The role of blood vessels in high-resolution volume conductor head modeling of EEG.

    Science.gov (United States)

    Fiederer, L D J; Vorwerk, J; Lucka, F; Dannhauer, M; Yang, S; Dümpelmann, M; Schulze-Bonhage, A; Aertsen, A; Speck, O; Wolters, C H; Ball, T

    2016-03-01

    Reconstruction of the electrical sources of human EEG activity at high spatio-temporal accuracy is an important aim in neuroscience and neurological diagnostics. Over the last decades, numerous studies have demonstrated that realistic modeling of head anatomy improves the accuracy of source reconstruction of EEG signals. For example, including a cerebro-spinal fluid compartment and the anisotropy of white matter electrical conductivity were both shown to significantly reduce modeling errors. Here, we for the first time quantify the role of detailed reconstructions of the cerebral blood vessels in volume conductor head modeling for EEG. To study the role of the highly arborized cerebral blood vessels, we created a submillimeter head model based on ultra-high-field-strength (7T) structural MRI datasets. Blood vessels (arteries and emissary/intraosseous veins) were segmented using Frangi multi-scale vesselness filtering. The final head model consisted of a geometry-adapted cubic mesh with over 17×10(6) nodes. We solved the forward model using a finite-element-method (FEM) transfer matrix approach, which allowed reducing computation times substantially and quantified the importance of the blood vessel compartment by computing forward and inverse errors resulting from ignoring the blood vessels. Our results show that ignoring emissary veins piercing the skull leads to focal localization errors of approx. 5 to 15mm. Large errors (>2cm) were observed due to the carotid arteries and the dense arterial vasculature in areas such as in the insula or in the medial temporal lobe. Thus, in such predisposed areas, errors caused by neglecting blood vessels can reach similar magnitudes as those previously reported for neglecting white matter anisotropy, the CSF or the dura - structures which are generally considered important components of realistic EEG head models. Our findings thus imply that including a realistic blood vessel compartment in EEG head models will be helpful to

  11. Peristaltic Pumping of Blood Through Small Vessels of Varying Cross-Section

    Science.gov (United States)

    Misra, J. C.; Maiti, S.

    2012-11-01

    The paper is devoted to a study of the peristaltic motion of blood in the micro-circulatory system. The vessel is considered to be of varying cross-section. The progressive peristaltic waves are taken to be of sinusoidal nature. Blood is considered to be a Herschel-Bulkley fluid. Of particular concern here is to investigate the effects of amplitude ratio, mean pressure gradient, yield stress and the power law index on the velocity distribution, streamline pattern and wall shear stress. On the basis of the derived analytical expression, extensive numerical calculations have been made. The study reveals that velocity of blood and wall shear stress are appreciably affected due to the non-uniform geometry of blood vessels. They are also highly sensitive to the magnitude of the amplitude ratio and the value of the fluid index.

  12. Do double gloves protect against contamination during cannulation of blood vessels? A prospective randomized study

    OpenAIRE

    Łukasz Szarpak; Andrzej Kurowski

    2014-01-01

    Background: Undamaged medical gloves protect medical personnel from contact with physiological fluids of the patient. Thus they protect the assistance provider from hand skin contamination with potentially infectious biological material. The aim of the study was to evaluate the occurrence of pierce, perforations or damage of medical gloves during cannulation of blood vessels. Materials and Methods: In the prospective randomized study 303 pairs of gloves, used during cannulation of blood vesse...

  13. Modeling blood flow in vessels with changeable caliber for physiology and biophysics courses.

    Science.gov (United States)

    Kozlova, E K; Badicov, V I; Chemysh, A M; Bogushevich, M S

    1997-06-01

    A model based on elementary principles of hydrodynamics and mathematics is proposed for classroom research on concepts related to blood flow physiology. This is an analog model of the vascular system in which blood flow is represented by electrical current flowing in a resistance circuit. The model permits analysis of the change in hemodynamics with local stenosis of both large and peripheral vessels. PMID:9227648

  14. Mass Spectrometry and Antibody-Based Characterization of Blood Vessels from Brachylophosaurus canadensis.

    Science.gov (United States)

    Cleland, Timothy P; Schroeter, Elena R; Zamdborg, Leonid; Zheng, Wenxia; Lee, Ji Eun; Tran, John C; Bern, Marshall; Duncan, Michael B; Lebleu, Valerie S; Ahlf, Dorothy R; Thomas, Paul M; Kalluri, Raghu; Kelleher, Neil L; Schweitzer, Mary H

    2015-12-01

    Structures similar to blood vessels in location, morphology, flexibility, and transparency have been recovered after demineralization of multiple dinosaur cortical bone fragments from multiple specimens, some of which are as old as 80 Ma. These structures were hypothesized to be either endogenous to the bone (i.e., of vascular origin) or the result of biofilm colonizing the empty osteonal network after degradation of original organic components. Here, we test the hypothesis that these structures are endogenous and thus retain proteins in common with extant archosaur blood vessels that can be detected with high-resolution mass spectrometry and confirmed by immunofluorescence. Two lines of evidence support this hypothesis. First, peptide sequencing of Brachylophosaurus canadensis blood vessel extracts is consistent with peptides comprising extant archosaurian blood vessels and is not consistent with a bacterial, cellular slime mold, or fungal origin. Second, proteins identified by mass spectrometry can be localized to the tissues using antibodies specific to these proteins, validating their identity. Data are available via ProteomeXchange with identifier PXD001738. PMID:26595531

  15. Making Ends Meet: Myeloid Cells Catalyze Blood Vessel Repair in the Brain.

    Science.gov (United States)

    Deczkowska, Aleksandra; Schwartz, Michal

    2016-05-17

    Hemorrhagic stroke, primarily caused by rupture of blood vessels in the brain, is a leading cause of death and disability in adults. In this issue of Immunity, Liu et al. (2016) demonstrate that repair of cerebrovascular ruptures can be directly mediated by myeloid cells. PMID:27192572

  16. Blood Vessel Segmentation Using Moving-Window Robust Automatic Threshold Selection

    NARCIS (Netherlands)

    Wilkinson, Michael H.F.; Wijbenga, Tsjipke; Vries, Gijs de; Westenberg, Michel A.

    2003-01-01

    Two moving-window methods, using either flat or Gaussian weighted windows, for local thresholding with Robust Automatic Threshold Selection are developed. The results show that fast segmentation of blood vessels against a varying background and noise is possible at modest computational cost. Volumes

  17. Finite-sized gas bubble motion in a blood vessel: non-Newtonian effects.

    Science.gov (United States)

    Mukundakrishnan, Karthik; Ayyaswamy, Portonovo S; Eckmann, David M

    2008-09-01

    We have numerically investigated the axisymmetric motion of a finite-sized nearly occluding air bubble through a shear-thinning Casson fluid flowing in blood vessels of circular cross section. The numerical solution entails solving a two-layer fluid model--a cell-free layer and a non-Newtonian core together with the gas bubble. This problem is of interest to the field of rheology and for gas embolism studies in health sciences. The numerical method is based on a modified front-tracking method. The viscosity expression in the Casson model for blood (bulk fluid) includes the hematocrit [the volume fraction of red blood cells (RBCs)] as an explicit parameter. Three different flow Reynolds numbers, Reapp=rholUmaxdmicroapp , in the neighborhood of 0.2, 2, and 200 are investigated. Here, rhol is the density of blood, Umax is the centerline velocity of the inlet Casson profile, d is the diameter of the vessel, and microapp is the apparent viscosity of whole blood. Three different hematocrits have also been considered: 0.45, 0.4, and 0.335. The vessel sizes considered correspond to small arteries, and small and large arterioles in normal humans. The degree of bubble occlusion is characterized by the ratio of bubble to vessel radius (aspect ratio), lambda , in the range 0.9 - --> +) imparted to the cell surface during bubble motion; (iii) large shear stress gradients together with sign reversals are ascribable to the development of a recirculation vortex at the rear of the bubble; (iv) computed magnitudes of shear stress gradients coupled with their sign reversals may correspond to levels that cause injury to the cell by membrane disruption through impulsive compression and stretching; and (v) for the vessel sizes and flow rates investigated, gravitational effects are negligible. PMID:18851139

  18. Implantable tissue-engineered blood vessels from human induced pluripotent stem cells.

    Science.gov (United States)

    Gui, Liqiong; Dash, Biraja C; Luo, Jiesi; Qin, Lingfeng; Zhao, Liping; Yamamoto, Kota; Hashimoto, Takuya; Wu, Hongwei; Dardik, Alan; Tellides, George; Niklason, Laura E; Qyang, Yibing

    2016-09-01

    Derivation of functional vascular smooth muscle cells (VSMCs) from human induced pluripotent stem cells (hiPSCs) to generate tissue-engineered blood vessels (TEBVs) holds great potential in treating patients with vascular diseases. Herein, hiPSCs were differentiated into alpha-smooth muscle actin (α-SMA) and calponin-positive VSMCs, which were seeded onto polymer scaffolds in bioreactors for vascular tissue growth. A functional TEBV with abundant collagenous matrix and sound mechanics resulted, which contained cells largely positive for α-SMA and smooth muscle myosin heavy chain (SM-MHC). Moreover, when hiPSC-derived TEBV segments were implanted into nude rats as abdominal aorta interposition grafts, they remained unruptured and patent with active vascular remodeling, and showed no evidence of teratoma formation during a 2-week proof-of-principle study. Our studies represent the development of the first implantable TEBVs based on hiPSCs, and pave the way for developing autologous or allogeneic grafts for clinical use in patients with vascular disease. PMID:27336184

  19. The influence on PGI2-like activity of blood vessel wall following γ ray irradiation

    International Nuclear Information System (INIS)

    In the previous work, it has been shown that the reaction of blood platelet aggregation is risen during the early days following γ ray irradiation of large doses. In this paper, the changes of Rat PGI2-like activity with inhibiting platelet aggregation after γ ray irradiation of 8 Gy are reported. The results indicated that the activity was reduced at the first day after radiation, then recovered at the third day, lowered again at the 5-7 days. The changes have significant concern between the increase of blood platelet aggregation of Rats and the inhibition of PGI2-like activity of blood vessel wall following γ ray irradiation

  20. On ultrasound-induced microbubble oscillation in a capillary blood vessel and its implications for the blood-brain barrier

    Science.gov (United States)

    Wiedemair, W.; Tuković, Ž.; Jasak, H.; Poulikakos, D.; Kurtcuoglu, V.

    2012-02-01

    The complex interaction between an ultrasound-driven microbubble and an enclosing capillary microvessel is investigated by means of a coupled, multi-domain numerical model using the finite volume formulation. This system is of interest in the study of transient blood-brain barrier disruption (BBBD) for drug delivery applications. The compliant vessel structure is incorporated explicitly as a distinct domain described by a dedicated physical model. Red blood cells (RBCs) are taken into account as elastic solids in the blood plasma. We report the temporal and spatial development of transmural pressure (Ptm) and wall shear stress (WSS) at the luminal endothelial interface, both of which are candidates for the yet unknown mediator of BBBD. The explicit introduction of RBCs shapes the Ptm and WSS distributions and their derivatives markedly. While the peak values of these mechanical wall parameters are not affected considerably by the presence of RBCs, a pronounced increase in their spatial gradients is observed compared to a configuration with blood plasma alone. The novelty of our work lies in the explicit treatment of the vessel wall, and in the modelling of blood as a composite fluid, which we show to be relevant for the mechanical processes at the endothelium.

  1. Peristaltic Pumping of Blood in micro-vessels of Non-uniform Cross-section

    CERN Document Server

    Misra, J C

    2010-01-01

    The paper is devoted to a study of the peristaltic motion of blood in the micro-circulatory system. The vessel is considered of non-uniform cross-section. The progressive peristaltic waves are taken to be of sinusoidal nature. The Reynolds number is considered to be small. Blood is considered to be a Herschel-Bulkley fluid. Of particular concern here is to investigate the effects of amplitude ratio, mean pressure gradient, yield stress and the power law index on the velocity distribution, streamline pattern and wall shear stress. Basing upon the study, extensive numerical calculations has been made. The study reveals that peristaltic pumping as well as velocity and wall shear stress are appreciably affected due to the non-uniform geometry of blood vessels. They are also highly sensitive to the magnitude of the amplitude of the amplitude ratio and the value of the fluid index.

  2. Optics based signal processing methods for intraoperative blood vessel detection and quantification in real time (Conference Presentation)

    Science.gov (United States)

    Chaturvedi, Amal; Shukair, Shetha A.; Le Rolland, Paul; Vijayvergia, Mayank; Subramanian, Hariharan; Gunn, Jonathan W.

    2016-03-01

    Minimally invasive operations require surgeons to make difficult cuts to blood vessels and other tissues with impaired tactile and visual feedback. This leads to inadvertent cuts to blood vessels hidden beneath tissue, causing serious health risks to patients and a non-reimbursable financial burden to hospitals. Intraoperative imaging technologies have been developed, but these expensive systems can be cumbersome and provide only a high-level view of blood vessel networks. In this research, we propose a lean reflectance-based system, comprised of a dual wavelength LED, photodiode, and novel signal processing algorithms for rapid vessel characterization. Since this system takes advantage of the inherent pulsatile light absorption characteristics of blood vessels, no contrast agent is required for its ability to detect the presence of a blood vessel buried deep inside any tissue type (up to a cm) in real time. Once a vessel is detected, the system is able to estimate the distance of the vessel from the probe and the diameter size of the vessel (with a resolution of ~2mm), as well as delineate the type of tissue surrounding the vessel. The system is low-cost, functions in real-time, and could be mounted on already existing surgical tools, such as Kittner dissectors or laparoscopic suction irrigation cannulae. Having been successfully validated ex vivo, this technology will next be tested in a live porcine study and eventually in clinical trials.

  3. A comparison of blood vessel features and local binary patterns for colorectal polyp classification

    Science.gov (United States)

    Gross, Sebastian; Stehle, Thomas; Behrens, Alexander; Auer, Roland; Aach, Til; Winograd, Ron; Trautwein, Christian; Tischendorf, Jens

    2009-02-01

    Colorectal cancer is the third leading cause of cancer deaths in the United States of America for both women and men. By means of early detection, the five year survival rate can be up to 90%. Polyps can to be grouped into three different classes: hyperplastic, adenomatous, and carcinomatous polyps. Hyperplastic polyps are benign and are not likely to develop into cancer. Adenomas, on the other hand, are known to grow into cancer (adenoma-carcinoma sequence). Carcinomas are fully developed cancers and can be easily distinguished from adenomas and hyperplastic polyps. A recent narrow band imaging (NBI) study by Tischendorf et al. has shown that hyperplastic polyps and adenomas can be discriminated by their blood vessel structure. We designed a computer-aided system for the differentiation between hyperplastic and adenomatous polyps. Our development aim is to provide the medical practitioner with an additional objective interpretation of the available image data as well as a confidence measure for the classification. We propose classification features calculated on the basis of the extracted blood vessel structure. We use the combined length of the detected blood vessels, the average perimeter of the vessels and their average gray level value. We achieve a successful classification rate of more than 90% on 102 polyps from our polyp data base. The classification results based on these features are compared to the results of Local Binary Patterns (LBP). The results indicate that the implemented features are superior to LBP.

  4. Adaptive ultrasonic measurement of blood vessel diameter and wall thickness: theory and experimental results.

    Science.gov (United States)

    Rafii, K; Jaffe, J S

    1998-01-01

    An adaptive ultrasonic technique for measuring blood vessel diameter and wall thickness is presented. This technique allows one to use a target-specific transmitted waveform/receiver filter to obtain a larger signal-to-noise ratio (SNR) in the received signal than conventional techniques. Generally, SNR of a received wave increases as the intensity of the transmit wave increases; however, because of the FDA limitations placed on the amount of transmit energy, it is important to be able to make the most efficient use of the energy that is available to obtain the best possible SNR in the received signal. Adaptive ultrasonic measurement makes the most efficient use of the energy that is available by placing the maximum amount of energy in the largest target scattering mode. This results in more energy backscatter from a given target, which leads to a higher SNR in the received waveform. Computer simulations of adaptive ultrasonic measurement of blood vessel diameter show that for a SNR of 0 dB in the transmitted waveform, the standard deviation of the diameter measurements for a custom-designed transmitted waveform is about two orders of magnitude less than the standard deviation of the diameter measurements using more conventional waveforms. Diameter and wall thickness measurement experiments were performed on a latex tube and a bovine blood vessel using both custom-made and conventionally used transmitted waveforms. Results show that the adaptively designed waveform gives a smaller uncertainty in the measurements. The adaptive ultrasonic blood vessel diameter and wall thickness measuring technique has potential applications in examining vessels which are either too deep inside the body or too small for conventional techniques to be used, because of the low SNR in the received signal. PMID:18244211

  5. Screening of specific binding peptide targeting blood vessel of human esophageal cancer in vivo in mice

    Institute of Scientific and Technical Information of China (English)

    ZHI Min; WU Kai-chun; HAO Zhi-ming; GUO Chang-cun; YAO Jia-yin

    2011-01-01

    Background Cancer of the esophagus and gastroesophageal junction remains a virulent malignancy with poor prognosis. Rapid progresses were made in chemotherapeutic agents and the development of molecular markers allowed better identification of candidates for targeted therapy. This study aimed to identify the candidate peptides used for anti-angiogenic therapy of esophageal cancer by in vivo screening C7C peptide library for peptides binding specifically to blood vessels of human esophageal cancer.Methods The phage displayed C7C peptide library was injected intravenously into mice bearing human esophageal tumor xenografts under renal capsule. After 5 rounds of screening, 13 clones were picked up individually and sequenced.During each round of screening, titers of phage recovery were calculated from tumor xenograft and control tissues.Homing of these 9 peptides to tumor vessel was detected by calculating phage titers in the tumor xenograft and control tissues (lung and spleen) after each phage was injected into mice model, and compared with the distribution of phage M13 and Ⅷ-related antigen in tumor xenograft by immunohistochemical staining. Comparisons among groups of data were made using one-way analysis of variance (ANOVA), followed by the Bonferroni multiple comparisons test.Results The number of phage recovered from tumor tissue of each round increased gradually in tumor group while decreased in control groups (P <0.01 in tumor and spleen, P <0.05 in lung). Immunohistochemical staining showed similar staining pattern with M13 antibody or Ⅷ-related antigen antibody, suggesting that phages displaying the selected peptides could home to blood vessel of human esophageal cancer. According to their DNA, 9 corresponding peptide sequences were deduced. And the homing ability to blood vessel of phages displaying the selected peptides was confirmed by comparing with their recovery in tumor and control tissues. Two motifs, YSXNXW and PXNXXN, were also obtained by

  6. Active Path Selection of Fluid Microcapsules in Artificial Blood Vessel by Acoustic Radiation Force

    Science.gov (United States)

    Masuda, Kohji; Muramatsu, Yusuke; Ueda, Sawami; Nakamoto, Ryusuke; Nakayashiki, Yusuke; Ishihara, Ken

    2009-07-01

    Micrometer-sized microcapsules collapse upon exposure to ultrasound. Use of this phenomenon for a drug delivery system (DDS), not only for local delivery of medication but also for gene therapy, should be possible. However, enhancing the efficiency of medication is limited because capsules in suspension diffuse in the human body after injection, since the motion of capsules in blood flow cannot be controlled. To control the behavior of microcapsules, acoustic radiation force was introduced. We detected local changes in microcapsule density by producing acoustic radiation force in an artificial blood vessel. Furthermore, we theoretically estimated the conditions required for active path selection of capsules at a bifurcation point in the artificial blood vessel. We observed the difference in capsule density at both in the bifurcation point and in alternative paths downstream of the bifurcation point for different acoustic radiation forces. Comparing the experimental results with those obtained theoretically, the conditions for active path selection were calculated from the acoustic radiation force and fluid resistance of the capsules. The possibility of controlling capsule flow towards a specific point in a blood vessel was demonstrated.

  7. Threadlike bundle of tubules running inside blood vessels New anatomical structure

    CERN Document Server

    Jiang, X; Shin, H; Lee, B; Choi, C; Soh, K; Cheun, B; Baik, K; Soh, K; Jiang, Xiaowen; Kim, Hee-kyeong; Shin, Hak-soo; Lee, Byong-chon; Choi, Chunho; Soh, Kyung-soon; Cheun, Byeung-soo; Baik, Ku-youn; Soh, Kwang-sup

    2002-01-01

    According to current anatomy, the arteries and veins do not have threadlike structures running inside the vessels. Despite such prevailing knowledge here we report on observation of a novel structure inside the blood vessels of rats and rabbits, which is a semi-transparent elastic bundle of tubules whose diameters are of 10$\\mu$m order. This is a rediscovery of the Bong Han ducts1,2 which have not been confirmed because the observing method was not known. We found a new procedure of observing the intra blood vessel ducts (IBVD) which are too thin, fragile, and semi-transparent to be detected in ordinary surgical operation. The method we contrived is to let blood be coagulated around the IBVD so that they become thick and strong by intravenous injection of 10 per cent dextrose solution at the vena femoralis. A piece of thickened IBVD sample is treated with urokinase to remove blood clots and the thin thread of IBVD is embedded inside of a string of fibrin

  8. ADAMTS1 alters blood vessel morphology and TSP1 levels in LNCaP and LNCaP-19 prostate tumors

    International Nuclear Information System (INIS)

    Decreased expression of the angiogenesis inhibitor ADAMTS1 (ADAM metallopeptidase with thrombospondin type 1 motif, 1) has previously been reported during prostate cancer progression. The aim of this study was to investigate the function of ADAMTS1 in prostate tumors. ADAMTS1 was downregulated by shRNA technology in the human prostate cancer cell line LNCaP (androgen-dependent), originally expressing ADAMTS1, and was upregulated by transfection in its subline LNCaP-19 (androgen-independent), expressing low levels of ADAMTS1. Cells were implanted subcutaneously in nude mice and tumor growth, microvessel density (MVD), blood vessel morphology, pericyte coverage and thrombospondin 1 (TSP1) were studied in the tumor xenografts. Modified expression of ADAMTS1 resulted in altered blood vessel morphology in the tumors. Low expression levels of ADAMTS1 were associated with small diameter blood vessels both in LNCaP and LNCaP-19 tumors, while high levels of ADAMTS1 were associated with larger vessels. In addition, TSP1 levels in the tumor xenografts were inversely related to ADAMTS1 expression. MVD and pericyte coverage were not affected. Moreover, upregulation of ADAMTS1 inhibited tumor growth of LNCaP-19, as evidenced by delayed tumor establishment. In contrast, downregulation of ADAMTS1 in LNCaP resulted in reduced tumor growth rate. The present study demonstrates that ADAMTS1 is an important regulatory factor of angiogenesis and tumor growth in prostate tumors, where modified ADAMTS1 expression resulted in markedly changed blood vessel morphology, possibly related to altered TSP1 levels

  9. "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

    observed experimentally. Most importantly, it suggests that the "sausaging" phenomenon is neither caused by a mechanical failure of the vessel wall due to a high blood pressure nor is it due to standing pressure waves caused by the beating of the heart. Rather, it is the expression of a general instability......Vascular damage induced by acute hypertension is preceded by a peculiar pattern where blood vessels show alternating regions of constrictions and dilations ("sausages on a string"). The pattern occurs in the smaller blood vessels, and it plays a central role in causing the vascular damage. A...... related vascular pattern has been observed in larger vessels from several organs during angiography. In the larger vessels the occurrence of the pattern does not appear to be related to acute hypertension. A unifying feature between the phenomenon in large and small vessels seems to be an increase in...

  10. The Emergence of Blood and Blood Vessels in the Embryo and Its Relevance to Postnatal Biology and Disease

    Science.gov (United States)

    Sills, Tiffany M.; Hirschi, Karen K.

    Blood and blood vessels develop in parallel within mammalian systems, and this temporal and spatial association has led to the confirmation of an endothelial origin of hematopoiesis. The extraembryonic yolk sac and aorto-gonado-mesonephros (AGM) region both contain a specialized population of endothelial cells ("hemogenic endothelium") that function to produce hematopoietic stem and progenitor cells, which then differentiate to provide the full complement of blood cells within the developing embryo and furthermore in the adult system. Therefore, this population has great therapeutic potential in the fields of regenerative medicine and tissue engineering. This chapter reviews the development of the vascular and hematopoietic systems, characterization and function of the hemogenic endothelium within embryonic and embryonic stem cell (ES cell) models, and speculate on the presence of such a population within the adult system. In order to harness this endothelial subtype for clinical application, we must understand both the normal functions of these cells and the potential for misregulation in disease states.

  11. Vascular Patterns in Iguanas and Other Squamates: Blood Vessels and Sites of Thermal Exchange.

    Directory of Open Access Journals (Sweden)

    William Ruger Porter

    Full Text Available Squamates use the circulatory system to regulate body and head temperatures during both heating and cooling. The flexibility of this system, which possibly exceeds that of endotherms, offers a number of physiological mechanisms to gain or retain heat (e.g., increase peripheral blood flow and heart rate, cooling the head to prolong basking time for the body as well as to shed heat (modulate peripheral blood flow, expose sites of thermal exchange. Squamates also have the ability to establish and maintain the same head-to-body temperature differential that birds, crocodilians, and mammals demonstrate, but without a discrete rete or other vascular physiological device. Squamates offer important anatomical and phylogenetic evidence for the inference of the blood vessels of dinosaurs and other extinct archosaurs in that they shed light on the basal diapsid condition. Given this basal positioning, squamates likewise inform and constrain the range of physiological thermoregulatory mechanisms that may have been found in Dinosauria. Unfortunately, the literature on squamate vascular anatomy is limited. Cephalic vascular anatomy of green iguanas (Iguana iguana was investigated using a differential-contrast, dual-vascular injection (DCDVI technique and high-resolution X-ray microcomputed tomography (μCT. Blood vessels were digitally segmented to create a surface representation of vascular pathways. Known sites of thermal exchange, consisting of the oral, nasal, and orbital regions, were given special attention due to their role in brain and cephalic thermoregulation. Blood vessels to and from sites of thermal exchange were investigated to detect conserved vascular patterns and to assess their ability to deliver cooled blood to the dural venous sinuses. Arteries within sites of thermal exchange were found to deliver blood directly and through collateral pathways. The venous drainage was found to have multiple pathways that could influence neurosensory

  12. Vascular Patterns in Iguanas and Other Squamates: Blood Vessels and Sites of Thermal Exchange.

    Science.gov (United States)

    Porter, William Ruger; Witmer, Lawrence M

    2015-01-01

    Squamates use the circulatory system to regulate body and head temperatures during both heating and cooling. The flexibility of this system, which possibly exceeds that of endotherms, offers a number of physiological mechanisms to gain or retain heat (e.g., increase peripheral blood flow and heart rate, cooling the head to prolong basking time for the body) as well as to shed heat (modulate peripheral blood flow, expose sites of thermal exchange). Squamates also have the ability to establish and maintain the same head-to-body temperature differential that birds, crocodilians, and mammals demonstrate, but without a discrete rete or other vascular physiological device. Squamates offer important anatomical and phylogenetic evidence for the inference of the blood vessels of dinosaurs and other extinct archosaurs in that they shed light on the basal diapsid condition. Given this basal positioning, squamates likewise inform and constrain the range of physiological thermoregulatory mechanisms that may have been found in Dinosauria. Unfortunately, the literature on squamate vascular anatomy is limited. Cephalic vascular anatomy of green iguanas (Iguana iguana) was investigated using a differential-contrast, dual-vascular injection (DCDVI) technique and high-resolution X-ray microcomputed tomography (μCT). Blood vessels were digitally segmented to create a surface representation of vascular pathways. Known sites of thermal exchange, consisting of the oral, nasal, and orbital regions, were given special attention due to their role in brain and cephalic thermoregulation. Blood vessels to and from sites of thermal exchange were investigated to detect conserved vascular patterns and to assess their ability to deliver cooled blood to the dural venous sinuses. Arteries within sites of thermal exchange were found to deliver blood directly and through collateral pathways. The venous drainage was found to have multiple pathways that could influence neurosensory tissue temperature

  13. Vascular Patterns in Iguanas and Other Squamates: Blood Vessels and Sites of Thermal Exchange

    Science.gov (United States)

    Porter, William Ruger; Witmer, Lawrence M.

    2015-01-01

    Squamates use the circulatory system to regulate body and head temperatures during both heating and cooling. The flexibility of this system, which possibly exceeds that of endotherms, offers a number of physiological mechanisms to gain or retain heat (e.g., increase peripheral blood flow and heart rate, cooling the head to prolong basking time for the body) as well as to shed heat (modulate peripheral blood flow, expose sites of thermal exchange). Squamates also have the ability to establish and maintain the same head-to-body temperature differential that birds, crocodilians, and mammals demonstrate, but without a discrete rete or other vascular physiological device. Squamates offer important anatomical and phylogenetic evidence for the inference of the blood vessels of dinosaurs and other extinct archosaurs in that they shed light on the basal diapsid condition. Given this basal positioning, squamates likewise inform and constrain the range of physiological thermoregulatory mechanisms that may have been found in Dinosauria. Unfortunately, the literature on squamate vascular anatomy is limited. Cephalic vascular anatomy of green iguanas (Iguana iguana) was investigated using a differential-contrast, dual-vascular injection (DCDVI) technique and high-resolution X-ray microcomputed tomography (μCT). Blood vessels were digitally segmented to create a surface representation of vascular pathways. Known sites of thermal exchange, consisting of the oral, nasal, and orbital regions, were given special attention due to their role in brain and cephalic thermoregulation. Blood vessels to and from sites of thermal exchange were investigated to detect conserved vascular patterns and to assess their ability to deliver cooled blood to the dural venous sinuses. Arteries within sites of thermal exchange were found to deliver blood directly and through collateral pathways. The venous drainage was found to have multiple pathways that could influence neurosensory tissue temperature

  14. Effects of X-irradiation on artificial blood vessel wall degradation by invasive tumor cells

    International Nuclear Information System (INIS)

    Artificial vessel wall cultures, constructed by growing arterial endothelial cells on preformed layers of rat smooth muscle cells, were used to evaluate the effects of X-irradiation on tumor cell-induced tissue degradation. Bovine endothelial cells had radiation sensitivities similar to those of rat smooth muscle cells. Preirradiation of smooth muscle cells, before the addition of human fibrosarcoma (HT 1080) cells, did not increase the rate of degradation and destruction by the invasive cells. However, the degradation rate was decreased if the cultures were irradiated after the addition of HT 1080 cells. The presence of bovine endothelial cells markedly inhibited the destructive abilities of fibrosarcoma cells, but preirradiation of artificial vessel walls substantially decreased their capabilities to resist HT 1080-induced lysis. These findings suggest that the abilities of blood vessels to limit extravasation may be compromised by ionizing radiation

  15. Comparison of two algorithms in the automatic segmentation of blood vessels in fundus images

    Science.gov (United States)

    LeAnder, Robert; Chowdary, Myneni Sushma; Mokkapati, Swapnasri; Umbaugh, Scott E.

    2008-03-01

    Effective timing and treatment are critical to saving the sight of patients with diabetes. Lack of screening, as well as a shortage of ophthalmologists, help contribute to approximately 8,000 cases per year of people who lose their sight to diabetic retinopathy, the leading cause of new cases of blindness [1] [2]. Timely treatment for diabetic retinopathy prevents severe vision loss in over 50% of eyes tested [1]. Fundus images can provide information for detecting and monitoring eye-related diseases, like diabetic retinopathy, which if detected early, may help prevent vision loss. Damaged blood vessels can indicate the presence of diabetic retinopathy [9]. So, early detection of damaged vessels in retinal images can provide valuable information about the presence of disease, thereby helping to prevent vision loss. Purpose: The purpose of this study was to compare the effectiveness of two blood vessel segmentation algorithms. Methods: Fifteen fundus images from the STARE database were used to develop two algorithms using the CVIPtools software environment. Another set of fifteen images were derived from the first fifteen and contained ophthalmologists' hand-drawn tracings over the retinal vessels. The ophthalmologists' tracings were used as the "gold standard" for perfect segmentation and compared with the segmented images that were output by the two algorithms. Comparisons between the segmented and the hand-drawn images were made using Pratt's Figure of Merit (FOM), Signal-to-Noise Ratio (SNR) and Root Mean Square (RMS) Error. Results: Algorithm 2 has an FOM that is 10% higher than Algorithm 1. Algorithm 2 has a 6%-higher SNR than Algorithm 1. Algorithm 2 has only 1.3% more RMS error than Algorithm 1. Conclusions: Algorithm 1 extracted most of the blood vessels with some missing intersections and bifurcations. Algorithm 2 extracted all the major blood vessels, but eradicated some vessels as well. Algorithm 2 outperformed Algorithm 1 in terms of visual clarity, FOM

  16. Painting blood vessels and atherosclerotic plaques with an adhesive drug depot

    Science.gov (United States)

    Kastrup, Christian J.; Nahrendorf, Matthias; Figueiredo, Jose Luiz; Lee, Haeshin; Kambhampati, Swetha; Lee, Timothy; Cho, Seung-Woo; Gorbatov, Rostic; Iwamoto, Yoshiko; Dang, Tram T.; Dutta, Partha; Yeon, Ju Hun; Cheng, Hao; Pritchard, Christopher D.; Vegas, Arturo J.; Siegel, Cory D.; MacDougall, Samantha; Okonkwo, Michael; Thai, Anh; Stone, James R.; Coury, Arthur J.; Weissleder, Ralph; Langer, Robert; Anderson, Daniel G.

    2012-01-01

    The treatment of diseased vasculature remains challenging, in part because of the difficulty in implanting drug-eluting devices without subjecting vessels to damaging mechanical forces. Implanting materials using adhesive forces could overcome this challenge, but materials have previously not been shown to durably adhere to intact endothelium under blood flow. Marine mussels secrete strong underwater adhesives that have been mimicked in synthetic systems. Here we develop a drug-eluting bioadhesive gel that can be locally and durably glued onto the inside surface of blood vessels. In a mouse model of atherosclerosis, inflamed plaques treated with steroid-eluting adhesive gels had reduced macrophage content and developed protective fibrous caps covering the plaque core. Treatment also lowered plasma cytokine levels and biomarkers of inflammation in the plaque. The drug-eluting devices developed here provide a general strategy for implanting therapeutics in the vasculature using adhesive forces and could potentially be used to stabilize rupture-prone plaques. PMID:23236189

  17. Fast Photoacoustic Imaging of Blood Vessels Based on an Annular Transducer Array

    International Nuclear Information System (INIS)

    We present a photoacoustic imaging system for rapid high-resolution photoacoustic imaging of blood vessels based on an annular transducer array. The annular transducer array consists of 256 elements arranged along a 300° arc with a 50-mm radius of curvature, using piezocomposite technology for high sensitivity and high signal-to-noise ratio. An eight-channel data acquisition system is applied to capture the photoacoustic signals using multiplexing and a limited-view filtered back projection algorithm is used to reconstruct the photoacoustic images. The experiments with phantom and blood vessels of a chicken are performed and clear photoacoustic images are obtained. The results demonstrate that the photoacoustic imaging system using the annular transducer array holds the potential application in monitoring neovascularization in tumor angiogenesis

  18. Tight junction between endothelial cells: the interaction between nanoparticles and blood vessels.

    Science.gov (United States)

    Zhang, Yue; Yang, Wan-Xi

    2016-01-01

    Since nanoparticles are now widely applied as food additives, in cosmetics and other industries, especially in medical therapy and diagnosis, we ask here whether nanoparticles can cause several adverse effects to human health. In this review, based on research on nanotoxicity, we mainly discuss the negative influence of nanoparticles on blood vessels in several aspects and the potential mechanism for nanoparticles to penetrate endothelial layers of blood vessels, which are the sites of phosphorylation of tight junction proteins (claudins, occludins, and ZO (Zonula occludens)) proteins, oxidative stress and shear stress. We propose a connection between the presence of nanoparticles and the regulation of the tight junction, which might be the key approach for nanoparticles to penetrate endothelial layers and then have an impact on other tissues and organs. PMID:27335757

  19. In Vivo μPIV Measurements of Blood Flow in Small Vessels of a Rat Model.

    Science.gov (United States)

    Wei, Timothy; Conner, Nadine; Russell, John; Legac, Paul

    2007-11-01

    Ongoing research at the University of Wisconsin Medical School is addressing the effects of perfusion of glottal tissue on voice production. Building on the approach developed by Gharib's group at CalTech for embryonic zebra fish, we have modified μPIV to measure flow in capillaries and small blood vessels in a live rat model. In lieu of seeding particles, the DPIV correlation algorithm tracks the motion of red blood cells moving through these vessels. The methodology will be presented along with a video sequence showing measurements made from muscle tissue laid nominally flat on a microscope stage. Challenges of measurements in three-dimensional geometries, i.e. the throat, will be discussed.

  20. Tight junction between endothelial cells: the interaction between nanoparticles and blood vessels

    Science.gov (United States)

    Zhang, Yue

    2016-01-01

    Summary Since nanoparticles are now widely applied as food additives, in cosmetics and other industries, especially in medical therapy and diagnosis, we ask here whether nanoparticles can cause several adverse effects to human health. In this review, based on research on nanotoxicity, we mainly discuss the negative influence of nanoparticles on blood vessels in several aspects and the potential mechanism for nanoparticles to penetrate endothelial layers of blood vessels, which are the sites of phosphorylation of tight junction proteins (claudins, occludins, and ZO (Zonula occludens)) proteins, oxidative stress and shear stress. We propose a connection between the presence of nanoparticles and the regulation of the tight junction, which might be the key approach for nanoparticles to penetrate endothelial layers and then have an impact on other tissues and organs. PMID:27335757

  1. Blood vessel crosstalk during organogenesis-focus on pancreas and endothelial cells.

    Science.gov (United States)

    Azizoglu, D Berfin; Cleaver, Ondine

    2016-09-01

    Blood vessels form a highly branched, interconnected, and largely stereotyped network of tubes that sustains every organ and tissue in vertebrates. How vessels come to take on their particular architecture, or how they are 'patterned,' and in turn, how they influence surrounding tissues are fundamental questions of organogenesis. Decades of work have begun to elucidate how endothelial progenitors arise and home to precise locations within tissues, integrating attractive and repulsive cues to build vessels where they are needed. Conversely, more recent findings have revealed an exciting facet of blood vessel interaction with tissues, where vascular cells provide signals to developing organs and progenitors therein. Here, we discuss the exchange of reciprocal signals between endothelial cells and neighboring tissues during embryogenesis, with a special focus on the developing pancreas. Understanding the mechanisms driving both sides of these interactions will be crucial to the development of therapies, from improving organ regeneration to efficient production of cell based therapies. Specifically, elucidating the interface of the vasculature with pancreatic lineages, including endocrine cells, will instruct approaches such as generation of replacement beta cells for Type I diabetes. WIREs Dev Biol 2016, 5:598-617. doi: 10.1002/wdev.240 For further resources related to this article, please visit the WIREs website. PMID:27328421

  2. Retinal hemodynamic oxygen reactivity assessed by perfusion velocity, blood oximetry and vessel diameter measurements

    DEFF Research Database (Denmark)

    Klefter, Oliver Niels; Lauritsen, Anne Øberg; Larsen, Michael

    2015-01-01

    PURPOSE: To test the oxygen reactivity of a fundus photographic method of measuring macular perfusion velocity and to integrate macular perfusion velocities with measurements of retinal vessel diameters and blood oxygen saturation. METHODS: Sixteen eyes in 16 healthy volunteers were studied at two...... perfusion velocities, short-term ICCs were 0.79-0.82 and long-term ICCs were 0.06-0.11. Intersession increases in blood glucose were associated with reductions in perfusion velocities (arterial p = 0.0067; venous p = 0.018). CONCLUSION: Oxygen reactivity testing supported that motion-contrast velocimetry is...... a valid method for assessing macular perfusion. Results were consistent with previous observations of hyperoxic blood flow reduction using blue field entoptic and laser Doppler velocimetry. Retinal perfusion seemed to be regulated around individual set points according to blood glucose levels...

  3. Surface modification of cellulose materials : from wood pulps to artificial blood vessels

    OpenAIRE

    Ahrenstedt, Lage

    2007-01-01

    This thesis describes the improvement of two radically different cellulose materials, paper and artificial blood vessels, constructed from two diverse cellulose sources, wood pulp and Acetobacter xylinum. The improvement of both materials was possible due to the natural affinity of the hemicellulose xyloglucan for cellulose. Chemical and mechanical pulps were treated with xyloglucan in the wet-end prior to hand sheet formation or by spray application of dry hand sheets, loading a comparable a...

  4. 3D MRI-based predictive control of a ferromagnetic microrobot navigating in blood vessels

    OpenAIRE

    Belharet, Karim; Folio, David; Ferreira, Antoine

    2010-01-01

    This paper presents an endovascular navigation of a ferromagneticmicrodevice using a MRI-based predictive control. The concept wasstudied for future development of microrobot designed to performminimally invasive interventions in remote sites accessible throughthe human cardiovascular system. A system software architecture ispresented illustrating the different software modules to allow 3Dnavigation of a microdevice in blood vessels, namely: (i) vesselpath extraction, (ii) magnetic gradient s...

  5. Simulation of Molecular Signaling in Blood Vessels: Software Design and Application to Atherogenesis

    OpenAIRE

    Felicetti, Luca; Femminella, Mauro; Reali, Gianluca

    2013-01-01

    This paper presents a software platform, named BiNS2, able to simulate diffusion-based molecular communications with drift inside blood vessels. The contribution of the paper is twofold. First a detailed description of the simulator is given, under the software engineering point of view, by highlighting the innovations and optimizations introduced. Their introduction into the previous version of the BiNS simulator was needed to provide to functions for simulating molecular signaling and commu...

  6. Sensory Nerves Determine the Pattern of Arterial Differentiation and Blood Vessel Branching in the Skin

    OpenAIRE

    Mukouyama, Yoh-suke; Shin, Donghun; Britsch, Stefan; Taniguchi, Masahiko; Anderson, David J.

    2002-01-01

    Nerves and blood vessels are branched structures, but whether their branching patterns are established independently or coordinately is not clear. Here we show that arteries, but not veins, are specifically aligned with peripheral nerves in embryonic mouse limb skin. Mutations that eliminate peripheral sensory nerves or Schwann cells prevent proper arteriogenesis, while those that disorganize the nerves maintain the alignment of arteries with misrouted axons. In vitro, sensory neurons or Schw...

  7. Ectopic fat storage in heart, blood vessels and kidneys in the pathogenesis of cardiovascular diseases

    OpenAIRE

    Montani, Jean-Pierre; Carroll, Joan F; Dwyer, Terry M.; Antic, Vladan; Yang, Zhihong; Abdul G Dulloo

    2005-01-01

    In humans and most animal models, the development of obesity leads not only to increased fat depots in classical adipose tissue locations but also to significant lipid deposits within and around other tissues and organs, a phenomenon known as ectopic fat storage. The purpose of this review is to explore the possible locations of ectopic fat in key target-organs of cardiovascular control (heart, blood vessels and kidneys) and to propose how ectopic fat storage can play a role in the pathogenes...

  8. Segmentation of retinal blood vessels using normalized Gabor filters and automatic thresholding

    OpenAIRE

    Mandlenkosi Victor Gwetu; Jules Raymond Tapamo; Serestina Viriri

    2014-01-01

    Although computerized retinal image blood vessel segmentation has been extensively researched, there is still room for improvement in the quality of the segmented images. Since retinal image analysis is still widely used in the diagnosis of diabetic retinopathy, efficient and accurate image characterization techniques are required. Previous work has mainly focused on improving segmentation accuracy rates with little regard to the false positives that are produced by illumination variation. T...

  9. Blood vessel staining in the myocardium for 3D visualization down to the smallest capillaries

    International Nuclear Information System (INIS)

    Blood vessels formed after medical interventions such as radiofrequency treatment have to be visualized down to the capillary level with diameters of about 5 μm to validate neo-vascularization. Synchrotron radiation-based micro-computed tomography (SRμCT) provides the necessary spatial resolution. Since both the vessels and the surrounding tissue mainly consist of water the difference in absorption is extremely weak. Therefore, it is necessary to search for appropriate contrast agents and to develop suitable staining protocols, which finally allow segmenting the vessel tree. Among the contrast agents used in medicine lyophilic salts with a mean particle diameter of 1.5 μm such as CaSO4, SrSO4 and BaSO4 are most appropriate to stain the vessels. The combination of these salts with a commercially available embedding kit (JB-4, Polysciences Inc.) allows tissue fixation and long-term storage in solid state. Intensity-based segmentation algorithms enable the vessel tree extraction in selected parts of the stained myocardium using the SRμCT data

  10. An Automatic Cognitive Graph-Based Segmentation for Detection of Blood Vessels in Retinal Images

    Directory of Open Access Journals (Sweden)

    Rasha Al Shehhi

    2016-01-01

    Full Text Available This paper presents a hierarchical graph-based segmentation for blood vessel detection in digital retinal images. This segmentation employs some of perceptual Gestalt principles: similarity, closure, continuity, and proximity to merge segments into coherent connected vessel-like patterns. The integration of Gestalt principles is based on object-based features (e.g., color and black top-hat (BTH morphology and context and graph-analysis algorithms (e.g., Dijkstra path. The segmentation framework consists of two main steps: preprocessing and multiscale graph-based segmentation. Preprocessing is to enhance lighting condition, due to low illumination contrast, and to construct necessary features to enhance vessel structure due to sensitivity of vessel patterns to multiscale/multiorientation structure. Graph-based segmentation is to decrease computational processing required for region of interest into most semantic objects. The segmentation was evaluated on three publicly available datasets. Experimental results show that preprocessing stage achieves better results compared to state-of-the-art enhancement methods. The performance of the proposed graph-based segmentation is found to be consistent and comparable to other existing methods, with improved capability of detecting small/thin vessels.

  11. Do double gloves protect against contamination during cannulation of blood vessels? A prospective randomized study

    Directory of Open Access Journals (Sweden)

    Łukasz Szarpak

    2014-04-01

    Full Text Available Background: Undamaged medical gloves protect medical personnel from contact with physiological fluids of the patient. Thus they protect the assistance provider from hand skin contamination with potentially infectious biological material. The aim of the study was to evaluate the occurrence of pierce, perforations or damage of medical gloves during cannulation of blood vessels. Materials and Methods: In the prospective randomized study 303 pairs of gloves, used during cannulation of blood vessels under simulated resuscitation, were analyzed. Gloves were tested by the water leak test. Results: The water test revealed 44 cases of damage to the gloves used during cannulation of blood vessels. Significant differences were noted in the frequency of damage to both the outer and single pairs of gloves and the inner pair of gloves. Conclusions: The study showed that the use of double gloves provides a higher level of security for a paramedic than the use of a single pair of gloves, however, double gloves reduce the manual dexterity of a paramedic. A large number of damages to gloves are not noticed by medical personnel during surgery. Med Pr 2014;65(2:271–278

  12. High-resolution in-situ LDV monitoring system for measuring velocity distribution in blood vessel

    Science.gov (United States)

    Kyoden, Tomoaki; Abe, Shotaro; Ishida, Hiroki; Akiguchi, Shunsuke; Andoh, Tsugunobu; Takada, Yogo; Teranishi, Tsunenobu; Hachiga, Tadashi

    2015-10-01

    We herein describe a cross-sectional multiple-point laser Doppler velocimetry (CS-MLDV) system for monitoring blood vessels that are sutured and connected during an operation. In order to observe the condition of a blood vessel during an operation, the previously developed linear MLDV (L-MLDV) system can realize velocity distribution imaging of the carotid artery in a living mouse by means of traverse laser light. We subsequently developed a CS-MLDV system, which can measure the instantaneous two-dimensional (2D) flow velocity, by upgrading the optical components and signal processing used in L-MLDV. The validity of the CS-MLDV results was verified through comparison with the results of a computational fluid dynamics (CFD) analysis. The results of the CFD analysis were similar to the experimental results obtained under the same flow field condition. Moreover, an instantaneous 2D velocity distribution can be obtained even for the case of flowing blood. Finally, we carried out in-vivo measurement in a mesenteric vessel of a mouse in order to demonstrate the potential of the CS-MLDV for use in surgery.

  13. Sensitivity analysis aimed at blood vessels detection using interstitial optical tomography during brain needle biopsy procedures.

    Science.gov (United States)

    Pichette, Julien; Goyette, Andréanne; Picot, Fabien; Tremblay, Marie-Andrée; Soulez, Gilles; Wilson, Brian C; Leblond, Frédéric

    2015-11-01

    A brain needle biopsy procedure is performed for suspected brain lesions in order to sample tissue that is subsequently analysed using standard histopathology techniques. A common complication resulting from this procedure is brain hemorrhaging from blood vessels clipped off during tissue extraction. Interstitial optical tomography (iOT) has recently been introduced by our group as a mean to assess the presence of blood vessels in the vicinity of the needle. The clinical need to improve safety requires the detection of blood vessels within 2 mm from the outer surface of the needle, since this distance is representative of the volume of tissue that is aspirated durirng tissue extraction. Here, a sensitivity analysis is presented to establish the intrinsic detection limits of iOT based on simulations and experiments using brain tissue phantoms. It is demonstrated that absorbers can be detected with diameters >300 μm located up to >2 mm from the biopsy needle core for bulk optical properties consistent with brain tissue. PMID:26600990

  14. Modeling the Role of the Glymphatic Pathway and Cerebral Blood Vessel Properties in Alzheimer's Disease Pathogenesis.

    Directory of Open Access Journals (Sweden)

    Christina Rose Kyrtsos

    Full Text Available Alzheimer's disease (AD is the most common cause of dementia in the elderly, affecting over 10% population over the age of 65 years. Clinically, AD is described by the symptom set of short term memory loss and cognitive decline, changes in mentation and behavior, and eventually long-term memory deficit as the disease progresses. On imaging studies, significant atrophy with subsequent increase in ventricular volume have been observed. Pathology on post-mortem brain specimens demonstrates the classic findings of increased beta amyloid (Aβ deposition and the presence of neurofibrillary tangles (NFTs within affected neurons. Neuroinflammation, dysregulation of blood-brain barrier transport and clearance, deposition of Aβ in cerebral blood vessels, vascular risk factors such as atherosclerosis and diabetes, and the presence of the apolipoprotein E4 allele have all been identified as playing possible roles in AD pathogenesis. Recent research has demonstrated the importance of the glymphatic system in the clearance of Aβ from the brain via the perivascular space surrounding cerebral blood vessels. Given the variety of hypotheses that have been proposed for AD pathogenesis, an interconnected, multilayer model offers a unique opportunity to combine these ideas into a single unifying model. Results of this model demonstrate the importance of vessel stiffness and heart rate in maintaining adequate clearance of Aβ from the brain.

  15. Measuring properties of nanoparticles in embryonic blood vessels: Towards a physicochemical basis for nanotoxicity

    Science.gov (United States)

    Clancy, Aisling A.; Gregoriou, Yiota; Yaehne, Kristin; Cramb, David T.

    2010-03-01

    The developing field of nanotoxicology aims to relate the physical properties of nanomaterials to potential risk when organisms are exposed to those materials. Regulators are interested in whether a nanoformulation would alter the risk of the native material. It may be that due to the physical nature of embryonic blood vessels (i.e. they are angiogenic and therefore leaky), embryos are at greater risk for bioaccumulation of nanoparticles (NPs) than mature organisms. To study the physicochemical nature of nanoparticle accumulation from embryonic blood vessels, one needs to measure the NP properties in situ, because these properties could be significantly dependent on environment. We have undertaken a study of the dynamics of CdSe/ZnS quantum dots and polystyrene nanospheres in the blood vessels of the chicken embryo chorioallantoic membrane (CAM). We show proof of principle that fluorescence correlation spectroscopy can be used in this system to determine the concentrations and hydrodynamic radii of NP solutions micro-injected into the CAM.

  16. An Experimental Study to Replace the Thoracic Descending Aorta for Pigs with a Self-Made Sutureless Blood Vessel

    Directory of Open Access Journals (Sweden)

    Fenglin Song

    2014-01-01

    Full Text Available To simplify the procedure of blood vessel replacement operation and shorten the vascular anastomosis time, we developed a special artificial blood vessel which can be connected to native blood vessels without suture. The self-made sutureless blood vessel (SMSBV was made from two titanium connectors and a Gore-Tex graft. To investigate blood compatibility and histocompatibility of the SMSBV, we carried thoracic descending aorta replacement using either SMSBV or Gore-Tex, respectively, in pigs. The aortic clamp time and the operative blood loss in the experimental group (using SMSBV were less than those in the control group (using Gore-Tex. The whole blood hematocrit, platelet count, plasma soluble P-selectin, plasma free hemoglobin, and interleukins 2, 6 at each time point were not different significantly between the two groups. Light microscopy and transmission electron microscopy examination showed there were layers of vascular smooth muscle cells and endothelial cells adhered in the inner wall of artificial blood vessel without any signs of thrombosis. Based on the result, we have drawn the conclusion that the application of SMSBV can significantly shorten the vascular anastomosis time, reduce operative blood loss, and show good blood and tissue compatibility.

  17. Bronchopulmonary dysplasia: where have all the vessels gone? Roles of angiogenic growth factors in chronic lung disease.

    Science.gov (United States)

    Thébaud, Bernard; Abman, Steven H

    2007-05-15

    Bronchopulmonary dysplasia and emphysema are significant global health problems at the extreme stages of life. Both are characterized by arrested alveolar development or loss of alveoli, respectively. Both lack effective treatment strategies. Knowledge about the genetic control of branching morphogenesis in mammals derives from investigations of the respiratory system in Drosophila, but mechanisms that regulate alveolar development remain poorly understood. Even less is known about regulation of the growth and development of the pulmonary vasculature. Understanding how alveoli and the underlying capillary network develop, and how these mechanisms are disrupted in disease states, are critical for developing effective therapies for lung diseases characterized by impaired alveolar structure. Recent observations have challenged old notions that the development of the blood vessels in the lung passively follows that of the airways. Rather, increasing evidence suggests that lung blood vessels actively promote alveolar growth during development and contribute to the maintenance of alveolar structures throughout postnatal life. Our working hypothesis is that disruption of angiogenesis impairs alveolarization, and that preservation of vascular growth and endothelial survival promotes growth and sustains the architecture of the distal airspace. Furthermore, the explosion of interest in stem cell biology suggests potential roles for endothelial progenitor cells in the pathogenesis or treatment of lung vascular disease. In this Pulmonary Perspective, we review recent data on the importance of the lung circulation, specifically examining the relationship between dysmorphic vascular growth and impaired alveolarization, and speculate on how these new insights may lead to novel therapeutic strategies for bronchopulmonary dysplasia. PMID:17272782

  18. Correlations Between the Density of Tryptase Positive Mast Cells (DMCT) and that of New Blood Vessels (CD105+) in Patients with Gastric Cancer.

    Science.gov (United States)

    Micu, Gianina Viorica; Stăniceanu, Florica; Sticlaru, Liana Cătălina; Popp, Cristiana Gabriela; Bastian, Alexandra Eugenia; Gramada, Eliza; Pop, G; Mateescu, R B; Rimbaş, M; Archip, Bianca; Bleotu, Coralia

    2016-06-01

    Mast cells proteases, tryptase and chymase are directly involved in the growth and progression of solid tumors due to their important role in tumor angiogenesis. We examined the density of tryptase positive mast cells and the mean density of new blood vessels in gastric malignant tumors of patients with and without Helicobacter pylori infection, using immunohistochemical staining for tryptase (for mast cells) and CD 105 (for new vessels). Tryptase and CD 105 expression was detected in gastrectomy specimens. In this study, mast cell density correlates with angiogenesis and the growth and progression of gastric cancer. It also shows that the participation of Helicobacter pylori infection in the growth and progress of gastric neoplasia is due to an increase of peritumoral angiogenesis, with subsequent local and distant tumor spread and perivascular growth, but without perineural and nodal involvement. PMID:27352440

  19. Automatic segmentation of blood vessels from retinal fundus images through image processing and data mining techniques

    Indian Academy of Sciences (India)

    R Geetharamani; Lakshmi Balasubramanian

    2015-09-01

    Machine Learning techniques have been useful in almost every field of concern. Data Mining, a branch of Machine Learning is one of the most extensively used techniques. The ever-increasing demands in the field of medicine are being addressed by computational approaches in which Big Data analysis, image processing and data mining are on top priority. These techniques have been exploited in the domain of ophthalmology for better retinal fundus image analysis. Blood vessels, one of the most significant retinal anatomical structures are analysed for diagnosis of many diseases like retinopathy, occlusion and many other vision threatening diseases. Vessel segmentation can also be a pre-processing step for segmentation of other retinal structures like optic disc, fovea, microneurysms, etc. In this paper, blood vessel segmentation is attempted through image processing and data mining techniques. The retinal blood vessels were segmented through color space conversion and color channel extraction, image pre-processing, Gabor filtering, image postprocessing, feature construction through application of principal component analysis, k-means clustering and first level classification using Naïve–Bayes classification algorithm and second level classification using C4.5 enhanced with bagging techniques. Association of every pixel against the feature vector necessitates Big Data analysis. The proposed methodology was evaluated on a publicly available database, STARE. The results reported 95.05% accuracy on entire dataset; however the accuracy was 95.20% on normal images and 94.89% on pathological images. A comparison of these results with the existing methodologies is also reported. This methodology can help ophthalmologists in better and faster analysis and hence early treatment to the patients.

  20. Cooperative phenomena in two-pulse, two-color laser photocoagulation of cutaneous blood vessels.

    Science.gov (United States)

    Barton, J K; Frangineas, G; Pummer, H; Black, J F

    2001-06-01

    A novel laser system has been developed to study the effects of multiple laser pulses of differing wavelengths on cutaneous blood vessels in vivo, using the hamster dorsal skin flap preparation and in vitro, using cuvettes of whole or diluted blood. The system permits sequenced irradiation with well-defined intrapulse spacing at 532 nm, using a long-pulse frequency-doubled Nd:YAG laser, and at 1064 nm, using a long-pulse Nd:YAG laser. Using this system, we have identified a parameter space where two pulses of different wavelengths act in a synergistic manner to effect permanent vessel damage at radiant exposures where the two pulses individually have little or no effect. Using a two-color pump-probe technique in vitro, we have identified a phenomenon we call greenlight-induced infrared absorption, where a pulse of green light causes photochemical and photothermal modifications to the chemical constituents of blood and results in enhanced infrared absorption. We identify a new chemical species, met-hemoglobin, not normally present in healthy human blood but formed during laser photocoagulation which we believe is implicated in the enhanced near-infrared absorption. PMID:11421070

  1. In vivo bioimaging as a novel strategy to detect doxorubicin-induced damage to gonadal blood vessels.

    Directory of Open Access Journals (Sweden)

    Hadas Bar-Joseph

    Full Text Available INTRODUCTION: Chemotherapy may induce deleterious effects in normal tissues, leading to organ damage. Direct vascular injury is the least characterized side effect. Our aim was to establish a real-time, in vivo molecular imaging platform for evaluating the potential vascular toxicity of doxorubicin in mice. METHODS: Mice gonads served as reference organs. Mouse ovarian or testicular blood volume and femoral arterial blood flow were measured in real-time during and after doxorubicin (8 mg/kg intravenously or paclitaxel (1.2 mg/kg administration. Ovarian blood volume was imaged by ultrasound biomicroscopy (Vevo2100 with microbubbles as a contrast agent whereas testicular blood volume and blood flow as well as femoral arterial blood flow was imaged by pulse wave Doppler ultrasound. Visualization of ovarian and femoral microvasculature was obtained by fluorescence optical imaging system, equipped with a confocal fiber microscope (Cell-viZio. RESULTS: Using microbubbles as a contrast agent revealed a 33% (P<0.01 decrease in ovarian blood volume already 3 minutes after doxorubicin injection. Doppler ultrasound depicted the same phenomenon in testicular blood volume and blood flow. The femoral arterial blood flow was impaired in the same fashion. Cell-viZio imaging depicted a pattern of vessels' injury at around the same time after doxorubicin injection: the wall of the blood vessels became irregular and the fluorescence signal displayed in the small vessels was gradually diminished. Paclitaxel had no vascular effect. CONCLUSION: We have established a platform of innovative high-resolution molecular imaging, suitable for in vivo imaging of vessels' characteristics, arterial blood flow and organs blood volume that enable prolonged real-time detection of chemotherapy-induced effects in the same individuals. The acute reduction in gonadal and femoral blood flow and the impairment of the blood vessels wall may represent an acute universal doxorubicin

  2. Multiparameter fluorescence mapping of nonprotein sulfhydryl status in relation to blood vessels and hypoxia in cervical carcinoma xenografts

    International Nuclear Information System (INIS)

    Purpose: Aberrant architecture of the tumor vasculature and temporal fluctuations in blood flow can result in tumor hypoxia. The aim of this study was to classify tumor hypoxia based on distance to blood vessels, and to characterize its biologic significance by determining levels of nonprotein sulfhydryls (NPSH) in hypoxic regions located proximally and distally to tumor blood vessels. Methods and Materials: A dual fluorescence method was developed for the spatial colocalization of the vasculature and hypoxia in frozen sections from SiHa cervical carcinoma xenografts. A parallel section was stained with the sulfhydryl stain mercury orange. Composite fluorescence images were generated by imaging and tiling individual fields of view into 2D image arrays. Image arithmetic techniques were combined with feature-based image segmentation to characterize expression of NPSH as a function of the hypoxic tumor microenvironment. Results: NPSH levels were higher in hypoxic areas of the SiHa xenografts (15.1±0.5 vs. 13.5±0.5 integrated optical density [IOD], p<0.03). When tumor hypoxia was classified by distance to the nearest visible blood vessel, significantly higher NPSH levels were found in hypoxic regions close to blood vessels than in regions at a distance from blood vessels. Conclusion: The results of this study indicate differential expression of NPSH levels in regions of hypoxia that are proximal or distal to blood vessels in SiHa tumors

  3. Stable and unstable crack growth in pressure vessel models

    International Nuclear Information System (INIS)

    Three identical steel pressure vessels with 254-mm (10-in.) dia, 38-mm (1.5-in.) wall thicknesses and long, deep machined and sharpened axially oriented flaws were tested at three different temperatures. The vessels were assembled by electron-beam welding cylindrical sections with substantially different toughnesses due to different heat treatments. Crack extension initiated in relatively brittle sections, and the cracks extended both stably and unstably, depending on test temperature, toward the tougher sections where crack arrest did and did not occur. Charpy impact specimens and both slow-bend and dynamic precracked Charpy specimens were used for material characterization. The behavior of the vessels is described and related to the Charpy data

  4. Accuracy and Precision of MR Blood Oximetry Based On the Long Paramagnetic Cylinder Approximation of Large Vessels

    OpenAIRE

    Langham, Michael C; Magland, Jeremy F; Epstein, Charles L.; Floyd, Thomas F; Wehrli, Felix W.

    2009-01-01

    An accurate non-invasive method to measure hemoglobin oxygen saturation (%HbO2) of deep-lying vessels without catheterization would have many clinical applications. Quantitative MRI may be the only imaging modality that can address this difficult and important problem. MR susceptometry-based oximetry for measuring blood oxygen saturation in large vessels models the vessel as a long paramagnetic cylinder immersed in an external field. The intravascular magnetic susceptibility relative to surro...

  5. Application of the (G'/G)-expansion method to nonlinear blood flow in large vessels

    International Nuclear Information System (INIS)

    As is widely known today, Navier-Stokes equations are used to describe blood flow in large vessels. In the past several decades, and even in very recent works, these equations have been reduced to Korteweg-de Vries (KdV), modified KdV or Boussinesq equations. In this paper, we avoid such simplifications and investigate the analytical traveling wave solutions of the one-dimensional generic Navier-Stokes equations, through the (G ' /G)-expansion method. These traveling wave solutions include hyperbolic functions, trigonometric functions and rational functions. Since some of them are not yet explored in the study of blood flow, we pay attention to hyperbolic function solutions and we show that the (G ' /G)-expansion method presents a wider applicability that allows us to bring out the widely known blood flow behaviors. The biological implications of the found solutions are discussed accordingly.

  6. Apparatus and method for examining a blood vessel of interest using radiation detected outside the body

    International Nuclear Information System (INIS)

    Stenotic atherosclerotic lesions of the coronary arteries are detected by injecting a number of particulate signal sources such as positron-emitting particles (e.g. gallium 68) into the blood of a subject to determine the velocity of blood flow through the coronary vessels. The particles are tracked in three dimensions whenever they appear in the region of the heart by means of high-resolution high-speed gamma detectors that surround the chest. These recordings of particle position as a function of time are analyzed, and the velocity of blood as it flows through the coronary artery is measured by timing the transit of the particle. From the accumulated data of multiple particle transits through the coronary circulation, a three-dimensional representation of the lumen of the coronary arterial system is constructed

  7. Computational blood flow and vessel wall modeling in a CT-based thoracic aorta after stent-graft implantation

    Science.gov (United States)

    Hazer, Dilana; Stoll, Markus; Schmidt, Eduard; Richter, Goetz-M.; Dillmann, Rüdiger

    2010-03-01

    Abnormal blood flow conditions and structural fatigue within stented vessels may lead to undesired failure causing death to the patient. Image-based computational modeling provides a physical and realistic insight into the patientspecific biomechanics and enables accurate predictive simulations of development, growth and failure of cardiovascular diseases as well as associated risks. Controlling the efficiency of an endovascular treatment is necessary for the evaluation of potential complications and predictions on the assessment of the pathological state. In this paper we investigate the effects of stent-graft implantation on the biomechanics in a patient-specific thoracic aortic model. The patient geometry and the implanted stent-graft are obtained from morphological data based on a CT scan performed during a controlling routine. Computational fluid dynamics (CFD) and computational structure mechanics (CSM) simulations are conducted based on the finite volume method (FVM) and on the finite element method (FEM) to compute the hemodynamics and the elastomechanics within the aortic model, respectively. Physiological data based on transient pressure and velocity profiles are used to set the necessary boundary conditions. Further, the effects of various boundary conditions and definition of contact interactions on the numerical stability of the blood flow and the vessel wall simulation results are also investigated. The quantification of the hemodynamics and the elastomechanics post endovascular intervention provides a realistic controlling of the state of the stented vessel and of the efficiency of the therapy. Consequently, computational modeling would help in evaluating individual therapies and optimal treatment strategies in the field of minimally invasive endovascular surgery.

  8. An Automated Graphical User Interface based System for the Extraction of Retinal Blood Vessels using Kirsch’s Template

    OpenAIRE

    Joshita Majumdar; Souvik Tewary; Shreyosi Chakraborty; Debasish Kundu; Sudipta Ghosh; Sauvik Das Gupta

    2015-01-01

    The assessment of Blood Vessel networks plays an important role in a variety of medical disorders. The diagnosis of Diabetic Retinopathy (DR) and its repercussions including micro aneurysms, haemorrhages, hard exudates and cotton wool spots is one such field. This study aims to develop an automated system for the extraction of blood vessels from retinal images by employing Kirsch’s Templates in a MATLAB based Graphical User Interface (GUI). Here, a RGB or Grey image of the retina (Fundus Phot...

  9. Histomorphometry of umbilical vessels of intrauterine growth restricted neonates

    Directory of Open Access Journals (Sweden)

    Sangeeta S. Kotrannavar

    2016-01-01

    Conclusions: IUGR is associated with significant structural changes in umbilical vessels of full term neonates. These changes are more obvious in HUV than human umbilical artery (HUA. It can be detected prenatally and used as an indicator of impending IUGR. [Int J Reprod Contracept Obstet Gynecol 2016; 5(1.000: 129-134

  10. An ensemble classification-based approach applied to retinal blood vessel segmentation.

    Science.gov (United States)

    Fraz, Muhammad Moazam; Remagnino, Paolo; Hoppe, Andreas; Uyyanonvara, Bunyarit; Rudnicka, Alicja R; Owen, Christopher G; Barman, Sarah A

    2012-09-01

    This paper presents a new supervised method for segmentation of blood vessels in retinal photographs. This method uses an ensemble system of bagged and boosted decision trees and utilizes a feature vector based on the orientation analysis of gradient vector field, morphological transformation, line strength measures, and Gabor filter responses. The feature vector encodes information to handle the healthy as well as the pathological retinal image. The method is evaluated on the publicly available DRIVE and STARE databases, frequently used for this purpose and also on a new public retinal vessel reference dataset CHASE_DB1 which is a subset of retinal images of multiethnic children from the Child Heart and Health Study in England (CHASE) dataset. The performance of the ensemble system is evaluated in detail and the incurred accuracy, speed, robustness, and simplicity make the algorithm a suitable tool for automated retinal image analysis. PMID:22736688

  11. A numerical analysis on the curved bileaflet Mechanical Heart Valve (MHV) : leaflet motion and blood flow in an elastic blood vessel

    International Nuclear Information System (INIS)

    In blood flow passing through the Mechanical Heart Valve (MHV) and elastic blood vessel, hemolysis and platelet activation causing thrombus formation can be seen owing to the shear stress in the blood. Also, fracture and deformation of leaflets can be observed depending on the shape and material properties of the leaflets which is opened and closed in a cycle. Hence, comprehensive study is needed on the hemodynamics which is associated with the motion of leaflet and elastic blood vessel in terms of fluid-structure interaction. In this paper, a numerical analysis has been performed for a three-dimensional pulsatile blood flow associated with the elastic blood vessel and curved bileaflet for multiple cycles in light of fluid-structure interaction. From this analysis fluttering phenomenon and rebound of the leaflet have been observed and recirculation and regurgitation have been found in the flow fields of the blood. Also, the pressure distribution and the radial displacement of the elastic blood vessel have been obtained. The motion of the leaflet and flow fields of the blood have shown similar tendency compared with the previous experiments carried out in other studies. The present study can contribute to the design methodology for the curved bileaflet mechanical heart valve. Furthermore, the proposed fluid-structure interaction method will be effectively used in various fields where the interaction between fluid flow and structure are involved

  12. In Silico Magnetic Nanocontainers Navigation in Blood Vessels: A Feedback Control Approach.

    Science.gov (United States)

    Do, Ton Duc; Noh, Yeongil; Kim, Myeong Ok; Yoon, Jungwon

    2016-06-01

    Magnetic nanoparticles (MNPs) are recently used in a drug delivery system to pass the blood brain barrier. However, because the magnetic force acting on particles is proportional to their volumes, as the size of particles is small, the large magnetic field is required to produce enough magnetic force for overcoming the hydrodynamic drag force as well as other forces in blood vessels. Other difficulties for controlling MNPs are the complicated behavior of hydrodynamic drag force and uncertain factors in their dynamics. Therefore, open-loop control methods cannot guarantee guiding every MNP to the correct location. Considering these challenges, this paper introduces a feedback control approach for magnetic nanoparticles (MNPs) in blood vessels. To the best of our knowledge, this is the first time feedback controller that is designed for MNPs without aggregation. Simulation studies in MATLAB and real-time verifications on a physical model in COMSOL-MATLAB interface are performed to prove the feasibility of the proposed approach. It is shown that the proposed control scheme can accurately and effectively navigate the MNP to the correct path with feasible hardware supports. PMID:27427720

  13. Regional heterogeneity in the reactivity of equine small pulmonary blood vessels.

    Science.gov (United States)

    Stack, Alice; Derksen, Frederik J; Williams, Kurt J; Robinson, N Edward; Jackson, William F

    2016-03-15

    Regional differences in large equine pulmonary artery reactivity exist. It is not known if this heterogeneity extends into small vessels. The hypothesis that there is regional heterogeneity in small pulmonary artery and vein reactivity to sympathomimetics (phenylephrine and isoproterenol) and a parasympathomimetic (methacholine) was tested using wire myography on small vessels from caudodorsal (CD) and cranioventral (CV) lung of 12 horses [9 mares, 3 geldings, 8.67 ± 0.81 (age ± SE) yr, of various breeds that had never raced]. To study relaxation, vessels were precontracted with U46619 (10(-6) M). Methacholine mechanism of action was investigated using l-nitroarginine methylester (l-NAME, 100 μM) and indomethacin (10 μM). Phenylephrine did not contract any vessels. Isoproterenol relaxed CD arteries more than CV arteries (maximum relaxation 28.18% and 48.67%; Log IC50 ± SE -7.975 ± 0.1327 and -8.033 ± 0.1635 for CD and CV, respectively, P < 0.0001), but not veins. Methacholine caused contraction of CD arteries (maximum contraction 245.4%, Log EC50 ± SE -6.475 ± 0.3341), and relaxation of CV arteries (maximum relaxation 40.14%, Log IC50 ± SE -6.791 ± 0.1954) and all veins (maximum relaxation 50.62%, Log IC50 ± SE -6.932 ± 0.1986) in a nonregion-dependent manner. l-NAME (n = 8, P < 0.0001) and indomethacin (n = 7, P < 0.0001) inhibited methacholine-induced relaxation of CV arteries, whereas indomethacin augmented CD artery contraction (n = 8, P < 0.0001). Our data demonstrate significant regional heterogeneity in small blood vessel reactivity when comparing the CD to the CV region of the equine lung. PMID:26769957

  14. Launch Conditions Might Affect the Formation of Blood Vessel in the Quail Chorioallantoic Membrane

    Science.gov (United States)

    Henry, M. K.; Unsworth, B. R.; Sychev, B. R.; Guryeva, T. S.; Dadasheva, O. A.; Piert, S. J.; Lagel, K. E.; Dubrovin, L. C.; Jahns, G. C.; Boda, K.; Sabo, V.; Samet, M. M.; Lelkes, P. I.

    1998-01-01

    AS 2 part of the first joint USA-Russian MIR/Shuttle program, fertilized quail eggs were flown on the MIR 18 mission. Post-flight examination indicated impaired survival of both the embryos in space and also of control embryos exposed to vibrational and g-forces simulating the conditions experienced during the launch of Progress 227. We hypothesized that excess mechanical forces and/or other conditions during the launch might cause abnormal development of the blood supply in the chorioallantoic membrane (CAM) leading to the impaired survival of the embryos. The CAM, a highly vascularized extraembryonic organ, provides for the oxygen exchange across the egg shell and is thus pivotal for proper embryonic development. To test our hypothesis, we compared angiogenesis In CAMS of eggs which were either exposed to the vibration and g-force profile simulating the conditions at launch of Progress 227 (synchronous controls), or kept under routine conditions in a laboratory Incubator (laboratory controls). At various time points during Incubation, the eggs were fixed in paraformaldehyde for subsequent dissection. At the time of dissection, the CAM was carefully lifted from the egg shell and examined as whole mounts by bright-field and fluorescent microscopy. The development or the vasculature (angiogenesis) was assessed from the density of blood vessels per viewing field and evaluated by computer aided image analysis. We observed a significant decrease In blood-vessel density in the synchronous controls versus "normal" laboratory controls beginning from day 10 of Incubation. The decrease in vascular density was restricted to the smallest vessels only, suggesting that conditions during the launch and/or during the subsequent Incubation of the eggs may affect the normal progress of angiogenesis in the CAM. Abnormal angiogenesis In the CAM might contribute to the impaired survival of the embryos observed in synchronous controls as well as in space.

  15. A Pulsatile Flow Phantom for Image-Guided HIFU Hemostasis of Blood Vessels

    International Nuclear Information System (INIS)

    A pulsatile flow phantom for studying ultrasound image-guided acoustic hemostasis in a controlled environment has been developed. An ex vivo porcine carotid artery was attached to the phantom and embedded in a visually and ultrasonically transparent gel. Heparinized porcine blood was pumped through the phantom. Power-Doppler and B-mode ultrasound were used to remotely target the HIFU focus to the site of a needle puncture. In nine trials, complete hemostasis was achieved after an average HIFU application of 55 +/- 34 seconds. The vessels remained patent after treatment. With this phantom, it will be possible to do controlled studies of ultrasound image-guided acoustic hemostasis

  16. Effect of Rolling Massage on Particle Moving Behaviour in Blood Vessels

    International Nuclear Information System (INIS)

    The rolling massage manipulation is a classic Chinese massage, which is expected to eliminate many diseases. Here the effect of the rolling massage on the particle moving property in the blood vessels under the rolling massage manipulation is studied by the lattice Boltzmann simulation. The simulation results show that the particle moving behaviour depends on the rolling velocity, the distance between particle position and rolling position. The average values, including particle translational velocity and angular velocity, increase as the rolling velocity increases almost linearly. The result is helpful to understand the mechanism of the massage and develop the rolling techniques. (cross-disciplinary physics and related areas of science and technology)

  17. Effects of a protein glycocalyx in the hemodynamics of small blood vessels

    Science.gov (United States)

    Dimakopoulos, Yiannis; Delidakis, George; Tsamopoulos, John

    2015-11-01

    Glycocalyx is a protein layer of approximate thickness 0.5 μm that lines vessel walls. We study the effects this layer has on the blood flow inside arterioles and venules, where the relative size of the glycocalyx is significant. To properly describe phenomena that naturally occur in blood flow, such as the inhomogeneous distribution of red blood cells and their aggregation, we use an improved viscoelastic constitutive model. The glycocalyx layer is modeled as fixed porous media. Cells cannot penetrate inside it, since its hydraulic permeability is very low, and the flow inside this layer is described by the equations for a viscous fluid with an extra Brinkman term to account for the effects the porous medium has on the flow. The closed set of equations is solved using the Finite Element method, assuming steady-state with dependence only in the r-direction. Our results are favorably compared with the in vivo velocity profiles in venules of mice produced by Damiano et al. (2004) and the formation of cell-free layer near glycocalyx. Flow inside the glycocalyx layer is found to be severely attenuated due to the low hydraulic permeability, which can have interesting implications in the transport of various substances form the blood to the tissues or in the use of shear stresses as signals for the endothelial surface cells. Finally, we simulate the transient blood flow under pulsatile conditions.

  18. Blood compatibility of artificial blood vessels probed by infrared spectroscopic imaging

    Science.gov (United States)

    Steiner, Gerald; Maitz, Manfred; Tunc, Sibel; Salzer, Reiner

    2006-02-01

    The determination of protein structure and function plays an important role in biomedical and biochemical research. Common techniques that give full structural information do not permit in-vivo measurements. Infrared spectroscopy has a sufficient sensitivity to examine the structure of proteins solution under in-situ conditions and even on surfaces. However, measurements at few spots on the surface are not suitable to find out the blood compatibility of the protein layer, because the changes in conformation occur often in small domains. Here we report on the investigations of adsorbed fibrinogen with FTIR imaging. FTIR imaging permits an identification of coagulation spots in the micrometer range and the identification of coagulation spots on the implant material.

  19. A kinematic study of pulsation in the dorsal blood vessel of the blackworm, Lumbriculus variegatus

    Directory of Open Access Journals (Sweden)

    Kameko Halfmann

    2011-01-01

    Full Text Available The aquatic oligochaete Lumbriculus variegatus has a segmented, dorsal blood vessel (DBV that acts as a peristaltic pump to move blood through the animal's closed circulatory system. We conducted a kinematic study using videography and computational modeling as a first step toward understanding the control of DBV pulsation. Results suggested that pulse rates were highest in the posterior segments, while interpulse intervals and intersegmental delays were longest in the midbody segments. Differences in the interpulse interval distributions across regions suggest that some peristaltic waves initiated in the posterior segments do not propagate all the way to the anterior segments. A simple model consisting of a chain of excitable neuromuscular units replicated these kinetics. This model may be useful in future research aimed at understanding the modulatory effect of biogenic amines on peristalsis of the DBV. Moreover, research into the mechanisms of peristalsis of the DBV may lead to insights into disorders of peristalsis in human and veterinary medicine

  20. Apparatus and method for examining a blood vessel of interest using radiation detected outside the body

    International Nuclear Information System (INIS)

    A gamma camera is described in detail for use in examining the blood circulation in vessels adjacent to the heart. The radiation source (e.g. 68Ga) emits positrons whose annihilation is localised and produces two 0.115 MeV gamma rays in exactly opposite directions. By detecting both gamma rays in coincidence in position sensitive multi-wire proportional chambers, lines may be drawn between detected pairs and the intersection of of all such pairs will define the position of the positron emitting source. The radiation source may be tracked in three dimensions by suitably arranging the detectors around the patient's chest. The position of the radiation source can be recorded as a function of time and hence provide information about the velocity of blood flow through each coronary artery. This information may help determine the extent, severity and location of stenotic lesions of the coronary arteries. (U.K.)

  1. An Ultrasound Simulation Model for the Pulsatile Blood Flow Modulated by the Motion of Stenosed Vessel Wall.

    Science.gov (United States)

    Zhang, Qinghui; Zhang, Yufeng; Zhou, Yi; Zhang, Kun; Zhang, Kexin; Gao, Lian

    2016-01-01

    This paper presents an ultrasound simulation model for pulsatile blood flow, modulated by the motion of a stenosed vessel wall. It aims at generating more realistic ultrasonic signals to provide an environment for evaluating ultrasound signal processing and imaging and a framework for investigating the behaviors of blood flow field modulated by wall motion. This model takes into account fluid-structure interaction, blood pulsatility, stenosis of the vessel, and arterial wall movement caused by surrounding tissue's motion. The axial and radial velocity distributions of blood and the displacement of vessel wall are calculated by solving coupled Navier-Stokes and wall equations. With these obtained values, we made several different phantoms by treating blood and the vessel wall as a group of point scatterers. Then, ultrasound echoed signals from oscillating wall and blood in the axisymmetric stenotic-carotid arteries were computed by ultrasound simulation software, Field II. The results show better consistency with corresponding theoretical values and clinical data and reflect the influence of wall movement on the flow field. It can serve as an effective tool not only for investigating the behavior of blood flow field modulated by wall motion but also for quantitative or qualitative evaluation of new ultrasound imaging technology and estimation method of blood velocity. PMID:27478840

  2. 3D Computer Simulations of Pulsatile Human Blood Flows in Vessels and in the Aortic Arch: Investigation of Non-Newtonian Characteristics of Human Blood

    CERN Document Server

    Sultanov, Renat A; Engelbrekt, Brent; Blankenbecler, Richard

    2008-01-01

    Methods of Computational Fluid Dynamics are applied to simulate pulsatile blood flow in human vessels and in the aortic arch. The non-Newtonian behaviour of the human blood is investigated in simple vessels of actual size. A detailed time-dependent mathematical convergence test has been carried out. The realistic pulsatile flow is used in all simulations. Results of computer simulations of the blood flow in vessels of two different geometries are presented. For pressure, strain rate and velocity component distributions we found significant disagreements between our results obtained with realistic non-Newtonian treatment of human blood and widely used method in literature: a simple Newtonian approximation. A significant increase of the strain rate and, as a result, wall sear stress distribution, is found in the region of the aortic arch. We consider this result as theoretical evidence that supports existing clinical observations and those models not using non-Newtonian treatment underestimate the risk of disru...

  3. Protective role of a novel human erythrocyte-derived depressing factor on blood vessels in rats

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The protective role of a human erythrocyte-derived depressing factor (EDDF) on blood vessels was evaluated. The experiments were carried out on 25male Wistar rats aged 6-8 weeks, which were divided into control (n = 8), calcium overload (n = 8) and NG-L-nitro-arginine hypertensive model groups (L-NNA,n = 9), respectively. The isolated vascular ring perfusion assay, two-photon laser scanning fluorescence microscopy (TPM) and transmitted electron microscope were used to examine the effect of EDDF on vascular function and ultrastructure. Results showed that the contractile response of calcium overload rats and L-NNA rats to phenylephrine (PE) was significantly enhanced compared with that of the control (P < 0.05), and EDDF (10-3 g @mL-1) remarkably decreased the vascular contractile response of control's and calcium overload rats (P < 0.05),while EDDF had no effect on that of L-NNA rats. EDDF also alleviated the ultrastructural lesion of aorta VSMC in calcium overload rats by easing the abnormal in the nucleus, mitochondrion and other organell. It is concluded that EDDF could efficiently protect blood vessels against injury by influencing Ca2+ transport and ameliorating the lesion of VSMC, and further supported the hypothesis that the NO-cGMP pathway might contribute to the vasodilation and partially antihypertensive mechanism of EDDF.``

  4. DSA Image Blood Vessel Skeleton Extraction Based on Anti-concentration Diffusion and Level Set Method

    Science.gov (United States)

    Xu, Jing; Wu, Jian; Feng, Daming; Cui, Zhiming

    Serious types of vascular diseases such as carotid stenosis, aneurysm and vascular malformation may lead to brain stroke, which are the third leading cause of death and the number one cause of disability. In the clinical practice of diagnosis and treatment of cerebral vascular diseases, how to do effective detection and description of the vascular structure of two-dimensional angiography sequence image that is blood vessel skeleton extraction has been a difficult study for a long time. This paper mainly discussed two-dimensional image of blood vessel skeleton extraction based on the level set method, first do the preprocessing to the DSA image, namely uses anti-concentration diffusion model for the effective enhancement and uses improved Otsu local threshold segmentation technology based on regional division for the image binarization, then vascular skeleton extraction based on GMM (Group marching method) with fast sweeping theory was actualized. Experiments show that our approach not only improved the time complexity, but also make a good extraction results.

  5. Imaging transient blood vessel fusion events in zebrafish by correlative volume electron microscopy.

    Directory of Open Access Journals (Sweden)

    Hannah E J Armer

    Full Text Available The study of biological processes has become increasingly reliant on obtaining high-resolution spatial and temporal data through imaging techniques. As researchers demand molecular resolution of cellular events in the context of whole organisms, correlation of non-invasive live-organism imaging with electron microscopy in complex three-dimensional samples becomes critical. The developing blood vessels of vertebrates form a highly complex network which cannot be imaged at high resolution using traditional methods. Here we show that the point of fusion between growing blood vessels of transgenic zebrafish, identified in live confocal microscopy, can subsequently be traced through the structure of the organism using Focused Ion Beam/Scanning Electron Microscopy (FIB/SEM and Serial Block Face/Scanning Electron Microscopy (SBF/SEM. The resulting data give unprecedented microanatomical detail of the zebrafish and, for the first time, allow visualization of the ultrastructure of a time-limited biological event within the context of a whole organism.

  6. Segmentation of retinal blood vessels using normalized Gabor filters and automatic thresholding

    Directory of Open Access Journals (Sweden)

    Mandlenkosi Victor Gwetu

    2014-12-01

    Full Text Available Although computerized retinal image blood vessel segmentation has been extensively researched, there is still room for improvement in the quality of the segmented images. Since retinal image analysis is still widely used in the diagnosis of diabetic retinopathy, efficient and accurate image characterization techniques are required. Previous work has mainly focused on improving segmentation accuracy rates with little regard to the false positives that are produced by illumination variation. This research work presents a hybrid approach towards the segmentation of retinal blood vessels. New approaches towards the reduction of background illumination variation are proposed using normalized Gabor filtering. These are the base-offset encoding and a modified version of an existing zero-integral kernel technique. The valley emphasis automatic thresholding scheme is used to segment the Gabor response images. Experiments are conducted on the DRIVE and STARE retinal image data sets. Accuracy rates of up to 94% are achieved through the zero-integral and base offset methods. This is comparable with results from literature, where the same data sets are segmented using other classification techniques. The median-offset method is found to most effectively reduce background illumination variation.

  7. Differential lectin binding on walls of thoraco-cervical blood vessels and lymphatics in rats.

    Science.gov (United States)

    Kagami, H; Uryu, K; Okamoto, K; Sakai, H; Kaneda, T; Sakanaka, M

    1991-08-01

    Lectin binding in the walls of large to medium-sized blood vessels and lymphatics in the rat thoraco-cervical region was examined histochemically. The tunica intima of the aorta and superficial cervical artery showed positive reactions with wheat germ agglutinin (WGA) and Concanavalin A (ConA) but not with Dolichus biflorus agglutinin (DBA). The tunica media of the aorta exhibited intense WGA binding, especially on the smooth muscle cells, but the tunica media of the superficial cervical artery did not react with the lectin. Neither ConA nor DBA bound to the tunica media of the aorta and superficial cervical artery. The tunica adventitia of both arteries contained sites binding the three lectins, although DBA reactivity declined as the vascular diameter decreased. The tunica intima of the superior vena cava and azygos vein exhibited positive WGA and ConA binding, whereas DBA binding was noted on only part of the tunica intima of the superior vena cava and not on that of the azygos vein. The tunica media and tunica adventitia were reactive for all three lectins. The WGA and ConA binding sites in the tunica adventitia showed loose networks, suggesting lectin binding on connective tissue elements interlacing among smooth muscle bundles. Lectin binding sites in the walls of lymphatics exhibited an arrangement similar to those in the walls of the veins. Moreover valves protruding into the lumen showed intense WGA and ConA binding and scattered DBA binding. Three other lectins (Ulex europaeus agglutinin, peanut agglutinin, Maclura pomifera) were examined, but they showed no reactions with the vessels. Thus, the differential binding of lectins on the walls of blood vessels and lymphatics of various sizes suggests the functional complexity of monosaccharide residues in the vascular walls. PMID:1758681

  8. Vascular network remodeling via vessel cooption, regression and growth in tumors

    CERN Document Server

    Bartha, K

    2016-01-01

    The transformation of the regular vasculature in normal tissue into a highly inhomogeneous tumor specific capillary network is described by a theoretical model incorporating tumor growth, vessel cooption, neo-vascularization, vessel collapse and cell death. Compartmentalization of the tumor into several regions differing in vessel density, diameter and in necrosis is observed for a wide range of parameters in agreement with the vessel morphology found in human melanoma. In accord with data for human melanoma the model predicts, that microvascular density (MVD, regarded as an important diagnostic tool in cancer treatment, does not necessarily determine the tempo of tumor progression. Instead it is suggested, that the MVD of the original tissue as well as the metabolic demand of the individual tumor cell plays the major role in the initial stages of tumor growth.

  9. Temporal patterns of blood flow and nitric oxide synthase expression affect macrophage accumulation and proliferation during collateral growth

    OpenAIRE

    Sager Hendrik B; Middendorff Ralf; Rauche Kim; Weil Joachim; Lieb Wolfgang; Schunkert Heribert; Ito Wulf D

    2010-01-01

    Abstract Background The involvement of collateral blood flow/fluid shear stress, nitric oxide (NO), and macrophages during collateral growth (arteriogenesis) is established, but their interplay remains paradoxical. Methods In order to further elucidate the "fluid shear stress/NO/macrophage" paradox, we investigated the time course of collateral blood flow (using a Doppler flow probe) and NOS expression (immunohistochemistry, Western blot) in growing rat collateral vessels after femoral artery...

  10. Analysis of deterministic and statistical approaches to fatigue crack growth in pressure vessels

    International Nuclear Information System (INIS)

    This work presents three approaches to the fatigue crack growth process in steel pressure vessels as applied to failure probability calculation. In the Thomson's methodology, the crack growth is the term that represents the mechanical behavior which along the time will take the pressure vessel to a structural failure. The first result of failure probability will be obtained considering a deterministic approach, since the crack growth laws are of a deterministic nature. This approach will provide a reference value. Next, two statistical approaches will be performed based on the fact that fatigue crack growth is a random phenomenon. One of them takes into account only the variability of experimental data, proposing a distribution function to represent the failure process. The other, the stochastic approach, considers the random nature of crack growth along time, by performing the randomization of a crack growth law. The solution of this stochastic equation is a transition distribution function fitted to experimental data. (author)

  11. Analysis of deterministic and statistical approaches to fatigue crack growth in pressure vessels

    Energy Technology Data Exchange (ETDEWEB)

    Francisco, Alexandre S.; Melo, P.F. Frutuoso e [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear. E-mail: frutuoso@lmn.con.ufrj.br

    2000-07-01

    This work presents three approaches to the fatigue crack growth process in steel pressure vessels as applied to failure probability calculation. In the Thomson's methodology, the crack growth is the term that represents the mechanical behavior which along the time will take the pressure vessel to a structural failure. The first result of failure probability will be obtained considering a deterministic approach, since the crack growth laws are of a deterministic nature. This approach will provide a reference value. Next, two statistical approaches will be performed based on the fact that fatigue crack growth is a random phenomenon. One of them takes into account only the variability of experimental data, proposing a distribution function to represent the failure process. The other, the stochastic approach, considers the random nature of crack growth along time, by performing the randomization of a crack growth law. The solution of this stochastic equation is a transition distribution function fitted to experimental data. (author)

  12. Fractals and fractal dimension of systems of blood vessels: An analogy between artery trees, river networks, and urban hierarchies

    CERN Document Server

    Chen, Yanguang

    2015-01-01

    An analogy between the fractal nature of networks of arteries and that of systems of rivers has been drawn in the previous works. However, the deep structure of the hierarchy of blood vessels has not yet been revealed. This paper is devoted to researching the fractals, allometric scaling, and hierarchy of blood vessels. By analogy with Horton-Strahler's laws of river composition, three exponential laws have been put forward. These exponential laws can be reconstructed and transformed into three linear scaling laws, which can be named composition laws of blood vessels network. From these linear scaling laws it follows a set of power laws, including the three-parameter Zipf's law on the rank-size distribution of blood vessel length and the allometric scaling law on the length-diameter relationship of blood vessels in different orders. The models are applied to the observed data on human beings and animals early given by other researchers, and an interesting finding is that human bodies more conform to natural r...

  13. Distinct mechanisms of relaxation to bioactive components from chamomile species in porcine isolated blood vessels

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, R.E., E-mail: Richard.roberts@nottingham.ac.uk; Allen, S.; Chang, A.P.Y.; Henderson, H.; Hobson, G.C.; Karania, B.; Morgan, K.N.; Pek, A.S.Y.; Raghvani, K.; Shee, C.Y.; Shikotra, J.; Street, E.; Abbas, Z.; Ellis, K.; Heer, J.K.; Alexander, S.P.H., E-mail: steve.alexander@nottingham.ac.uk

    2013-11-01

    German chamomile (Matricaria recutita L.), a widely-used herbal medicine, has been reported to have a wide range of biological effects, including smooth muscle relaxation. The aim of this study was to compare the effects of representative compounds from chamomile (apigenin, luteolin, (−)-α-bisabolol, farnesene, umbelliferone; 3–30 μM) on vascular tone using porcine coronary and splenic arteries mounted for isometric tension recording in isolated tissue baths and precontracted with the thromboxane-mimetic U46619. Apigenin, luteolin, and (−)-α-bisabolol produced slow, concentration-dependent relaxations in both the coronary and splenic arteries that were not blocked by inhibition of nitric oxide synthase or potassium channels. Removal of extracellular calcium inhibited the relaxations to all three compounds, and these compounds also inhibited calcium re-addition-evoked contractions, indicating that the relaxation response may be mediated through inhibition of calcium influx. Apigenin and luteolin, but not (−)-α-bisabolol, enhanced the relaxation to the nitric oxide donor sodium nitroprusside, indicating that apigenin and luteolin may act to regulate cyclic GMP levels. Umbelliferone produced a rapid, transient relaxation in the splenic artery, but not the coronary artery, that was inhibited by L-NAME and removal of the endothelium, suggesting an influence on nitric oxide production. Farnesene, at concentrations up to 30 μM, was without effect in either blood vessel. In conclusion, hydroxylated compounds (apigenin, luteolin and (−)-α-bisabolol) found in chamomile all caused a slow relaxation of isolated blood vessels through an effect on calcium influx. Umbelliferone, on the other hand, produced a rapid, transient relaxation dependent upon release of nitric oxide from the endothelium. - Highlights: • Apigenin, luteolin, and (-)-α-bisabolol are present in chamomile. • They produced slow, concentration-dependent relaxations in arteries. • These

  14. Blood-Vessel Mimicking Structures by Stereolithographic Fabrication of Small Porous Tubes Using Cytocompatible Polyacrylate Elastomers, Biofunctionalization and Endothelialization

    OpenAIRE

    Birgit Huber; Sascha Engelhardt; Wolfdietrich Meyer; Hartmut Krüger; Annika Wenz; Veronika Schönhaar; Tovar, Günter E. M.; Kluger, Petra J.; Kirsten Borchers

    2016-01-01

    Blood vessel reconstruction is still an elusive goal for the development of in vitro models as well as artificial vascular grafts. In this study, we used a novel photo-curable cytocompatible polyacrylate material (PA) for freeform generation of synthetic vessels. We applied stereolithography for the fabrication of arbitrary 3D tubular structures with total dimensions in the centimeter range, 300 µm wall thickness, inner diameters of 1 to 2 mm and defined pores with a constant diameter of appr...

  15. Label-free 3D imaging of microstructure, blood and lymphatic vessels within tissue beds in vivo

    OpenAIRE

    Zhi, Zhongwei; Jung, Yeongri; Wang, Ruikang K.

    2012-01-01

    This letter reports the use of an ultrahigh resolution optical microangiography (OMAG) system for simultaneous 3D imaging of microstructure, lymphatic and blood vessels without the use of exogenous contrast agent. An automatic algorithm is developed to segment the lymphatic vessels from the microstructural images, based on the fact that the lymph fluid is optically transparent. The OMAG system is developed that utilizes a broadband supercontinuum light source, providing an axial resolution of...

  16. 3-D trajectory model for MDT using micro-spheres implanted within large blood vessels

    Science.gov (United States)

    Choomphon-anomakhun, Natthaphon; Natenapit, Mayuree

    2016-09-01

    Implant assisted magnetic drug targeting (IA-MDT) using ferromagnetic spherical targets implanted within large blood vessels and subjected to a uniform externally applied magnetic field (H0) has been investigated and reported for the first time. The capture areas (As) of magnetic drug carrier particles (MDCPs) were determined from the analysis of particle trajectories simulated from equations of motion. Then, the effects of various parameters, such as types of ferromagnetic materials in the targets and MDCPs, blood flow rates, mass fraction of the ferromagnetic material in the MDCPs, average radii of MDCPs (Rp) and the strength of H0 on the As were obtained. Furthermore, the effects of saturation magnetization of the ferromagnetic materials in the MDCPs and within the targets on the As were analyzed. After this, the suitable strengths of H0 and Rp for IA-MDT designs were reported. Dimensionless As, ranging from 2 to 7, was obtained with Rp ranging from 500 to 2500 nm, μ0H0 less than 0.8 T and a blood flow rate of 0.1 m s-1. The target-MDCP materials considered are iron-iron, iron-magnetite and SS409-magnetite, respectively.

  17. The Effect of Silver Nanofibers on the Deformation Properties of Blood Vessels: Towards the Development of New Nanotechnologies to Prevent Rupture of Aneurysms

    Directory of Open Access Journals (Sweden)

    Miguel Gonzalez

    2014-01-01

    Full Text Available An aneurysm is the result of a widening or ballooning of a portion of a blood vessel. The rupture of an aneurysm occurs when the mechanical stress acting on the inner wall exceeds the failure strength of the blood vessel. We propose an innovative approach to prevent the rupture of an aneurysm based on the use of nanotechnology to improve the strength of the blood vessel. We present results on the effect of silver nanofibers on the resistance toward deformation of blood vessels. The silver nanofibers are grown on the surface of the blood vessels. The nanofibers are 120±30 nm in diameter and 2.7±0.8 μm in length. The deformation per applied force of blood vessels was found to decrease from 0.15 m/N in control blood vessels to 0.003 m/N in blood vessels treated with the nanofibers. This represents an increase in the resistance towards deformation of a factor of 50. The increase in the resistance towards deformation is clinically significant since blood pressure increases by factors slightly larger than one in the human body. Treatment of blood vessels with silver nanofibers is a potential translational clinical tool for preventing rupture of aneurysms in a clinical setting.

  18. Multi-detector spiral CT study of the relationships between pulmonary ground-glass nodules and blood vessels

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Feng; Li, Ming; Ge, Xiaojun; Ren, Qingguo; Hua, Yanqing [Huadong Hospital Fudan University, Department of Radiology, Shanghai (China); Zheng, Xiangpeng [Huadong Hospital Fudan University, Department of Radiation Oncology, Shanghai (China); Chen, Yan [Huadong Hospital Fudan University, Department of Pathology, Shanghai (China); Lv, Fangzhen [Huadong Hospital Fudan University, Department of Thoracic Surgery, Shanghai (China)

    2013-12-15

    To investigate the relationships between pulmonary ground-glass nodules (GGN) and blood vessels and their diagnostic values in differentiating GGNs. Multi-detector spiral CT imaging of 108 GGNs was retrospectively reviewed. The spatial relationships between GGNs and supplying blood vessels were categorized into four types: I, vessels passing by GGNs; II, intact vessels passing through GGNs; III, distorted, dilated or tortuous vessels seen within GGNs; IV, more complicated vasculature other than described above. Relationship types were correlated to pathologic and/or clinical findings of GGNs. Of 108 GGNs, 10 were benign, 24 preinvasive nodules and 74 adenocarcinomas that were pathologically proven. Types I, II, III and IV vascular relationships were observed in 9, 58, 21 and 20 GGNs, respectively. Type II relationship was the dominating relationship for each GGN group, but significant differences were shown among them. Correlation analysis showed strong correlation between invasive adenocarcinoma and type III and IV relationships. Subgroup analysis indicated that type III was more commonly seen in IAC with comparison to type IV more likely seen in MIA. Different GGNs have different relationships with vessels. Understanding and recognising characteristic GGN-vessel relationships may help identify which GGNs are more likely to be malignant. (orig.)

  19. Accuracy and precision of MR blood oximetry based on the long paramagnetic cylinder approximation of large vessels.

    Science.gov (United States)

    Langham, Michael C; Magland, Jeremy F; Epstein, Charles L; Floyd, Thomas F; Wehrli, Felix W

    2009-08-01

    An accurate noninvasive method to measure the hemoglobin oxygen saturation (%HbO(2)) of deep-lying vessels without catheterization would have many clinical applications. Quantitative MRI may be the only imaging modality that can address this difficult and important problem. MR susceptometry-based oximetry for measuring blood oxygen saturation in large vessels models the vessel as a long paramagnetic cylinder immersed in an external field. The intravascular magnetic susceptibility relative to surrounding muscle tissue is a function of oxygenated hemoglobin (HbO(2)) and can be quantified with a field-mapping pulse sequence. In this work, the method's accuracy and precision was investigated theoretically on the basis of an analytical expression for the arbitrarily oriented cylinder, as well as experimentally in phantoms and in vivo in the femoral artery and vein at 3T field strength. Errors resulting from vessel tilt, noncircularity of vessel cross-section, and induced magnetic field gradients were evaluated and methods for correction were designed and implemented. Hemoglobin saturation was measured at successive vessel segments, differing in geometry, such as eccentricity and vessel tilt, but constant blood oxygen saturation levels, as a means to evaluate measurement consistency. The average standard error and coefficient of variation of measurements in phantoms were cylinder approximation of the incremental field. PMID:19526517

  20. Low level arsenic promotes progressive inflammatory angiogenesis and liver blood vessel remodeling in mice

    International Nuclear Information System (INIS)

    The vascular effects of arsenic in drinking water are global health concerns contributing to human disease worldwide. Arsenic targets the endothelial cells lining blood vessels, and endothelial cell activation or dysfunction may underlie the pathogenesis of both arsenic-induced vascular diseases and arsenic-enhanced tumorigenesis. The purpose of the current studies was to demonstrate that exposing mice to drinking water containing environmentally relevant levels of arsenic promoted endothelial cell dysfunction and pathologic vascular remodeling. Increased angiogenesis, neovascularization, and inflammatory cell infiltration were observed in Matrigel plugs implanted in C57BL/6 mice following 5-week exposures to 5-500 ppb arsenic [Soucy, N.V., Mayka, D., Klei, L.R., Nemec, A.A., Bauer, J.A., Barchowsky, A., 2005. Neovascularization and angiogenic gene expression following chronic arsenic exposure in mice. Cardiovasc.Toxicol 5, 29-42]. Therefore, functional in vivo effects of arsenic on endothelial cell function and vessel remodeling in an endogenous vascular bed were investigated in the liver. Liver sinusoidal endothelial cells (LSEC) became progressively defenestrated and underwent capillarization to decrease vessel porosity following exposure to 250 ppb arsenic for 2 weeks. Sinusoidal expression of PECAM-1 and laminin-1 proteins, a hallmark of capillarization, was also increased by 2 weeks of exposure. LSEC caveolin-1 protein and caveolae expression were induced after 2 weeks of exposure indicating a compensatory change. Likewise, CD45/CD68-positive inflammatory cells did not accumulate in the livers until after LSEC porosity was decreased, indicating that inflammation is a consequence and not a cause of the arsenic-induced LSEC phenotype. The data demonstrate that the liver vasculature is an early target of pathogenic arsenic effects and that the mouse liver vasculature is a sensitive model for investigating vascular health effects of arsenic

  1. Large blood vessel stretch in lumbar spine through anterior surgical approach: An experimental study in adult goat

    Directory of Open Access Journals (Sweden)

    Liehua Liu

    2014-01-01

    Full Text Available Background: Various anterior lumbar surgical approaches, including the minimally invasive approach, have greatly improved in recent years. Vascular complications resulting from ALIF are frequently reported. Little information is available about the safety of large blood vessel stretch. We evaluated the right side stretch limit (RSSL of the abdominal aorta (AAA and the inferior vena cava (IVC without blood flow occlusion and investigated stretch-induced histological injury and thrombosis in the iliac and femoral arteries and veins and the stretched vessels. Materials and Methods: The RSSL of blood vessels in five adult goats was measured by counting the number of 0.5-cm-thick wood slabs that were inserted between the right lumbar edge and the stretch hook. Twenty seven adult goats were divided into three groups to investigate histological injury and thrombosis under a stretch to 0.5 cm (group I 1.5 cm (group II for 2 h, or no stretch (group III. Blood vessel samples from groups I and II were analyzed on postsurgical days 1, 3, and 7. Thrombogenesis was examined in the iliac and femoral arteries and veins. Results: The RSSL of large blood vessels in front of L4/5 was 1.5 cm from the right lumbar edge. All goats survived surgery without complications. No injury or thrombosis in the large blood vessels in front of the lumbar vertebrae and in the iliac or femoral arteries and veins was observed. Under light microscopy, group I showed slight swelling of endothelial cells in the AAA and no histological injury of the IVC. The AAA of group II showed endothelial cell damage, unclear organelles, and incomplete cell connections by electron microscopy. Conclusions: The AAA and IVC in a goat model can be stretched by ≤0.5 cm, with no thrombosis in the AAA, IVC, iliac or femoral arteries and veins.

  2. Comparison of the number of gingival blood vessels between type 2 diabetes mellitus and chronic periodontitis patients: An immunohistological study

    Directory of Open Access Journals (Sweden)

    Gautami Subhadra Penmetsa

    2015-01-01

    Full Text Available Background: The relationship between diabetes and periodontitis has been studied for more than 50 years and is generally agreed that the periodontal disease is more prevalent in diabetic patients compared to nondiabetics. Vascular changes like increased thickness of basement membrane in small vessels has been reported in diabetic patients, but the quantity of blood vessels in gingiva of diabetic patients has not been discussed much. The aim of this study was to compare the number of blood vessels in gingiva between chronic periodontitis (CP patients, CP with diabetes (type 2, and normal healthy gingiva. Materials and Methods: The study included 75 patients, divided into three groups of 25 patients each-Group I with healthy periodontium (HP, Group II with CP, and Group III with CP with diabetes mellitus (CPDM.Gingival biopsies were obtained from the subjects undergoing crown lengthening procedure for Group I, and in patients with CP and in CPDM biopsies were collected from teeth undergoing extraction. Sections were prepared for immune histochemical staining with CD34. Results: Difference was observed in the average number of blood vessels when compared between HP, CP, and CPDM groups. Statistical significant difference was observed when the HP and CP groups and HP and CPDM groups were compared. Conclusion: The results of the study indicated that the number of blood vessels in gingival connective tissue is significantly higher in CP and CPDM patients.

  3. Wrong theories on the origin of blood vessels: Polybus and De Natura Hominis.

    Science.gov (United States)

    Shoja, Mohammadali M; Tubbs, R Shane; Loukas, Marios; Ardalan, Mohammad R

    2008-06-01

    Polybus of Cos (approximately 400 B.C.) was the son-in-law and the successor of Hippocrates. He is credited with founding the school of Dogmatism, and writing "The Nature of Man" which was important in advancing the theory of the four body humors (humoralism). Some earlier scholars negated Polybus' role as an independent medical figure. However, Corpus Aristotelicum quoted him as having a unique theory regarding the body vasculature which stated that this system was composed of four pairs of blood vessels originating from the head and that these supplied the whole body. In an interpretation of this theory, we opined that numerological mysticism might have been the common motive for both Hippocrates' humoralism and Polybus' theory of the vasculature. A discussion on this issue is presented. PMID:18164081

  4. Ultrastructural analysis of small blood vessels in skin biopsies in CADASIL

    Directory of Open Access Journals (Sweden)

    Lačković Vesna

    2008-01-01

    Full Text Available Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL is an inherited small- and medium-artery disease of the brain caused by mutation of the Notch3 gene. Very often, this disease is misdiagnosed. We examined skin biopsies in two members of the first discovered Serbian family affected by CADASIL. Electron microscopy showed that skin blood vessels of both patients contain numerous deposits of granular osmiophilic material (GOM around vascular smooth muscle cells (VSMCs. We observed degeneration of VSMCs, reorganization of their cytoskeleton and dense bodies, disruption of myoendothelial contacts, and apoptosis. Our results suggest that the presence of GOM in small skin arteries represents a specific marker in diagnosis of CADASIL.

  5. Lattice Boltzmann simulation of behaviour of particles moving in blood vessels under the rolling massage

    International Nuclear Information System (INIS)

    The rolling massage is one of the most important manipulations in Chinese massage, which is expected to eliminate many diseases. Here, the effect of the rolling massage on a pair of particles moving in blood vessels under rolling massage manipulation is studied by the lattice Boltzmann simulation. The simulated results show that the motion of each particle is considerably modified by the rolling massage, and it depends on the relative rolling velocity, the rolling depth, and the distance between particle position and rolling position. Both particles' translational average velocities increase almost linearly as the rolling velocity increases, and obey the same law. The increment of the average relative angular velocity for the leading particle is smaller than that of the trailing one. The result is helpful for understanding the mechanism of the massage and to further develop the rolling techniques. (classical areas of phenomenology)

  6. Streaming flow from ultrasound contrast agents by acoustic waves in a blood vessel model.

    Science.gov (United States)

    Cho, Eunjin; Chung, Sang Kug; Rhee, Kyehan

    2015-09-01

    To elucidate the effects of streaming flow on ultrasound contrast agent (UCA)-assisted drug delivery, streaming velocity fields from sonicated UCA microbubbles were measured using particle image velocimetry (PIV) in a blood vessel model. At the beginning of ultrasound sonication, the UCA bubbles formed clusters and translated in the direction of the ultrasound field. Bubble cluster formation and translation were faster with 2.25MHz sonication, a frequency close to the resonance frequency of the UCA. Translation of bubble clusters induced streaming jet flow that impinged on the vessel wall, forming symmetric vortices. The maximum streaming velocity was about 60mm/s at 2.25MHz and decreased to 15mm/s at 1.0MHz for the same acoustic pressure amplitude. The effect of the ultrasound frequency on wall shear stress was more noticeable. Maximum wall shear stress decreased from 0.84 to 0.1Pa as the ultrasound frequency decreased from 2.25 to 1.0MHz. The maximum spatial gradient of the wall shear stress also decreased from 1.0 to 0.1Pa/mm. This study showed that streaming flow was induced by bubble cluster formation and translation and was stronger upon sonication by an acoustic wave with a frequency near the UCA resonance frequency. Therefore, the secondary radiant force, which is much stronger at the resonance frequency, should play an important role in UCA-assisted drug delivery. PMID:26025507

  7. Distinct cellular mechanisms of blood vessel fusion in the zebrafish embryo.

    Science.gov (United States)

    Herwig, Lukas; Blum, Yannick; Krudewig, Alice; Ellertsdottir, Elin; Lenard, Anna; Belting, Heinz-Georg; Affolter, Markus

    2011-11-22

    Although many of the cellular and molecular mechanisms of angiogenesis have been intensely studied [1], little is known about the processes that underlie vascular anastomosis. We have generated transgenic fish lines expressing an EGFP-tagged version of the junctional protein zona occludens 1 (ZO1) to visualize individual cell behaviors that occur during vessel fusion and lumen formation in vivo. These life observations show that endothelial cells (ECs) use two distinct morphogenetic mechanisms, cell membrane invagination and cord hollowing to generate different types of vascular tubes. During initial steps of anastomosis, cell junctions that have formed at the initial site of cell contacts expand into rings, generating a cellular interface of apical membrane compartments, as defined by the localization of the apical marker podocalyxin-2 (Pdxl2). During the cord hollowing process, these apical membrane compartments are brought together via cell rearrangements and extensive junctional remodeling, resulting in lumen coalescence and formation of a multicellular tube. Vessel fusion by membrane invagination occurs adjacent to a preexisting lumen in a proximal to distal direction and is blood-flow dependent. Here, the invaginating inner cell membrane undergoes concomitant apicobasal polarization and the vascular lumen is formed by the extension of a transcellular lumen through the EC, which forms a unicellular or seamless tube. PMID:22079115

  8. Degradation profile and preliminary clinical testing of a resorbable device for ligation of blood vessels.

    Science.gov (United States)

    Aminlashgari, Nina; Höglund, Odd V; Borg, Niklas; Hakkarainen, Minna

    2013-06-01

    A resorbable device for ligation of blood vessels was developed and tested in vitro to reveal the degradation profile of the device and to predict the clinical performance in terms of adequate mechanical support during a healing period of 1week. In addition, preliminary clinical testing was performed that showed complete hemostasis and good tissue grip of renal arteries in five pigs. The device was made by injection molding of poly(glycolide-co-trimethylene carbonate) triblock copolymer, and it consisted of a case with a locking mechanism connected to a partly perforated flexible band. A hydrolytic degradation study was carried out for 7, 30 and 60days in water and buffer medium, following the changes in mass, water absorption, pH and mechanical properties. A new rapid matrix-free laser desorption ionization-mass spectrometry (LDI-MS) method was developed for direct screening of degradation products released into the degradation medium. The combination of LDI-MS and electrospray ionization-mass spectrometry analyses enabled the comparison of the degradation product patterns in water and buffer medium. The identified degradation products were rich in trimethylene carbonate units, indicating preferential hydrolysis of amorphous regions where trimethylene units are located. The crystallinity of the material was doubled after 60days of hydrolysis, additionally confirming the preferential hydrolysis of trimethylene carbonate units and the enrichment of glycolide units in the remaining solid matrix. The mechanical performance of the perforated band was followed for the first week of hydrolysis and the results suggest that sufficient strength is retained during the healing time of the blood vessels. PMID:23438863

  9. Distinct mechanisms of relaxation to bioactive components from chamomile species in porcine isolated blood vessels.

    Science.gov (United States)

    Roberts, R E; Allen, S; Chang, A P Y; Henderson, H; Hobson, G C; Karania, B; Morgan, K N; Pek, A S Y; Raghvani, K; Shee, C Y; Shikotra, J; Street, E; Abbas, Z; Ellis, K; Heer, J K; Alexander, S P H

    2013-11-01

    German chamomile (Matricaria recutita L.), a widely-used herbal medicine, has been reported to have a wide range of biological effects, including smooth muscle relaxation. The aim of this study was to compare the effects of representative compounds from chamomile (apigenin, luteolin, (-)-α-bisabolol, farnesene, umbelliferone; 3-30 μM) on vascular tone using porcine coronary and splenic arteries mounted for isometric tension recording in isolated tissue baths and precontracted with the thromboxane-mimetic U46619. Apigenin, luteolin, and (-)-α-bisabolol produced slow, concentration-dependent relaxations in both the coronary and splenic arteries that were not blocked by inhibition of nitric oxide synthase or potassium channels. Removal of extracellular calcium inhibited the relaxations to all three compounds, and these compounds also inhibited calcium re-addition-evoked contractions, indicating that the relaxation response may be mediated through inhibition of calcium influx. Apigenin and luteolin, but not (-)-α-bisabolol, enhanced the relaxation to the nitric oxide donor sodium nitroprusside, indicating that apigenin and luteolin may act to regulate cyclic GMP levels. Umbelliferone produced a rapid, transient relaxation in the splenic artery, but not the coronary artery, that was inhibited by L-NAME and removal of the endothelium, suggesting an influence on nitric oxide production. Farnesene, at concentrations up to 30 μM, was without effect in either blood vessel. In conclusion, hydroxylated compounds (apigenin, luteolin and (-)-α-bisabolol) found in chamomile all caused a slow relaxation of isolated blood vessels through an effect on calcium influx. Umbelliferone, on the other hand, produced a rapid, transient relaxation dependent upon release of nitric oxide from the endothelium. PMID:23845591

  10. First two cases of living related liver transplantation with complicated anatomy of blood vessels in Beijing

    Institute of Scientific and Technical Information of China (English)

    Wen-Han Wu; Yuan-Lian Wan; Long Lee; Yin-Mo Yang; Yan-Ting Huang; Chao-Long Chen; Sheung-Tat Fan

    2004-01-01

    AIM: Living related liver transplantation (LRLT) has been developed in response to the paediatric organ donor shortage.Though it has been succeeded in many centers worldwide,the safety of the donor is still a major concern, especially in donors with anatomy variation. We succeeded in performing the first two cases of living related liver transplantation with complicated anatomy of blood vessels as a way to overcome cadaveric organ shortage in Beijing.METHODS: Two patients, with congenital liver fibrosis and congenital biliary atresia were performed with living donor liver transplantation in our hospital and then followed up from November 12 to December 13, 2001. The two living donors, mother and father, were healthy aged 34 and 35years. One right lobe (segment Ⅴ, Ⅵ, Ⅶ, Ⅷ) and one left lateral lobe (segment Ⅱ and Ⅲ) were used. The grafts weighed 394 g and 300 g. The ratio of graft weight to the standard liver volume (SLV) of donors was 68% and 27%.The graft weight to recipient body weight ratio was 3.2%and 4.4%. The graft weight to recipient estimated standard liver mass (ESLM) ratio was 63% and 85%. The two donors had complicated blood vessel variation.RESULTS: Two patients undergone living donor liver transplantation had good results. Abnormal liver function with high bilirubin level appeared in a few days after operation, but liver function returned to normal one month after operation with bilirubin level almost decreased to near normal. No bleeding, thrombosis, infection and bile leakage occurred. One had an acute rejection and recovered.The two donors recovered in two weeks. One had slight fever because of a little collection in abdomen and recovered after paracentesis and drainage.CONCLUSION: Living donor liver transplantation has been proved to be a good way that offers a unique opportunity of getting a timely liver graft as a response to shortage of pediatric donors, though it could be a technically difficult operation if there is anatomical

  11. Use of the Structure of Blood Vessel for Detection of Brain Aneurysm and Route Search to Brain Aneurysm

    Directory of Open Access Journals (Sweden)

    Toshihide Miyagi

    2013-08-01

    Full Text Available In this research, we constructed functions that are necessary for the operation simulation system which assists medical students to inhibit brain aneurysm from exploding. The system reported in this paper is "detection of blood vessels", "detection of brain aneurysm" and "route planning to brain aneurysm". Not only the detection method but also the method to reduce the miss detection is realized for the detection of blood vessel. Finally, the future work will be shown including construction of head model consisting of artery, vein, brain and cranium.

  12. Tumor blood vessel "normalization" improves the therapeutic efficacy of boron neutron capture therapy (BNCT) in experimental oral cancer

    Energy Technology Data Exchange (ETDEWEB)

    D. W. Nigg

    2012-01-01

    We previously demonstrated the efficacy of BNCT mediated by boronophenylalanine (BPA) to treat tumors in a hamster cheek pouch model of oral cancer with no normal tissue radiotoxicity and moderate, albeit reversible, mucositis in precancerous tissue around treated tumors. It is known that boron targeting of the largest possible proportion of tumor cells contributes to the success of BNCT and that tumor blood vessel normalization improves drug delivery to the tumor. Within this context, the aim of the present study was to evaluate the effect of blood vessel normalization on the therapeutic efficacy and potential radiotoxicity of BNCT in the hamster cheek pouch model of oral cancer.

  13. In vivo nanomechanical imaging of blood-vessel tissues directly in living mammals using atomic force microscopy

    Science.gov (United States)

    Mao, Youdong; Sun, Quanmei; Wang, Xiufeng; Ouyang, Qi; Han, Li; Jiang, Lei; Han, Dong

    2009-07-01

    Atomic force microscopy (AFM) is difficult to achieve in living mammals but is necessary for understanding mechanical properties of tissues in their native form in organisms. Here we report in vivo nanomechanical imaging of blood-vessel tissues directly in living mammalians by AFM combined with surgical operations. Nanomechanical heterogeneity of blood vessels is observed across the diverse microenvironments of the same tissues in vivo. This method is further used to measure the counteractive nanomechanical changes in real time during drug-induced vasodilation and vasoconstriction in vivo, demonstrating appealing potential in characterization of in vivo nanomechanical dynamics of native tissues.

  14. Predicting effects of blood flow rate and size of vessels in a vasculature on hyperthermia treatments using computer simulation

    Directory of Open Access Journals (Sweden)

    Shih Tzu-Ching

    2010-03-01

    Full Text Available Abstract Background Pennes Bio Heat Transfer Equation (PBHTE has been widely used to approximate the overall temperature distribution in tissue using a perfusion parameter term in the equation during hyperthermia treatment. In the similar modeling, effective thermal conductivity (Keff model uses thermal conductivity as a parameter to predict temperatures. However the equations do not describe the thermal contribution of blood vessels. A countercurrent vascular network model which represents a more fundamental approach to modeling temperatures in tissue than do the generally used approximate equations such as the Pennes BHTE or effective thermal conductivity equations was presented in 1996. This type of model is capable of calculating the blood temperature in vessels and describing a vasculature in the tissue regions. Methods In this paper, a countercurrent blood vessel network (CBVN model for calculating tissue temperatures has been developed for studying hyperthermia cancer treatment. We use a systematic approach to reveal the impact of a vasculature of blood vessels against a single vessel which most studies have presented. A vasculature illustrates branching vessels at the periphery of the tumor volume. The general trends present in this vascular model are similar to those shown for physiological systems in Green and Whitmore. The 3-D temperature distributions are obtained by solving the conduction equation in the tissue and the convective energy equation with specified Nusselt number in the vessels. Results This paper investigates effects of size of blood vessels in the CBVN model on total absorbed power in the treated region and blood flow rates (or perfusion rate in the CBVN on temperature distributions during hyperthermia cancer treatment. Also, the same optimized power distribution during hyperthermia treatment is used to illustrate the differences between PBHTE and CBVN models. Keff (effective thermal conductivity model delivers the

  15. Soluble vascular endothelial growth factor in various blood transfusion components

    DEFF Research Database (Denmark)

    Nielsen, Hans Jørgen; Werther, K; Mynster, T;

    1999-01-01

    sVEGF was determined in nonfiltered and prestorage white cell-reduced whole blood (WB), buffy coat-depleted saline-adenine-glucose-mannitol (SAGM) blood, platelet-rich plasma (PRP), and buffy coat-derived platelet (BCP) pools obtained from volunteer, healthy blood donors. As a control, total content...... of platelet-derived soluble plasminogen activator inhibitor type 1 (sPAI-1) was determined by an EIA in the same samples. Finally, the extracellular accumulation of sVEGF was determined in nonfiltered WB and SAGM blood during storage for 35 days and in BCP pools during storage for 7 days. RESULTS: In......BACKGROUND: Blood transfusion may reduce survival after curative surgery for solid tumors. This may be related to extracellular content of cancer growth factors present in transfusion components. Vascular endothelial growth factor (VEGF) is a potent stimulator of angiogenesis in solid tumors. The...

  16. Blood Outgrowth Endothelial Cells Increase Tumor Growth Rates and Modify Tumor Physiology: Relevance for Therapeutic Targeting

    Energy Technology Data Exchange (ETDEWEB)

    Pagan, Jonathan, E-mail: jdpagan@uams.edu; Przybyla, Beata; Jamshidi-Parsian, Azemat [Department of Radiation Oncology, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, AR 72205 (United States); Gupta, Kalpna [Vascular Biology Center and Division of Hematology-Oncology Transplantation, Department of Medicine, University of Minnesota Medical School, MN 72223 (United States); Griffin, Robert J. [Department of Radiation Oncology, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, AR 72205 (United States)

    2013-02-18

    Endothelial cell precursors from human peripheral blood have been shown to home to areas of neovascularization and may assist tumor growth by increasing or fortifying blood vessel growth. In the present study, the influence of these cells on tumor growth and physiology was investigated and the role of these cells as a therapeutic target or in determining treatment sensitivity was tested. After isolation from human blood and expansion in vitro, actively growing cells with verified endothelial phenotype (Blood Outgrowth Endothelial Cell, BOEC) were injected i.v. into tumor bearing mice for three consecutive days. The growth rate was significantly enhanced in relatively small RERF human lung tumors (i.e., less than 150 mm{sup 3}) grown in immunocompromised mice by an average of 1.5-fold while it had no effect when injections were given to animals bearing larger tumors. There were no signs of toxicity or unwanted systemic effects. We also observed evidence of increased perfusion, vessel number, response to 15 Gy radiation and oxygenation in RERF tumors of animals injected with BOECs compared to control tumors. In addition, FSaII murine fibrosarcoma tumors were found to grow faster upon injection of BOECs. When FSaII tumors were subjected to a partial thermal ablation treatment using high intensity focused ultrasound (HIFU) there was consistently elevated detection of fluorescently labeled and i.v. injected endothelial precursors in the tumor when analyzed with optical imaging and/or histological preparations. Importantly, we also observed that BOECs treated with the novel anti-angiogenic peptide anginex in-vitro, show decreased proliferation and increased sensitivity to radiation. In vivo, the normal increase in FSaII tumor growth induced by injected BOECs was blunted by the addition of anginex treatment. It appears that endothelial precursors may significantly contribute to tumor vessel growth, tumor progression and/or repair of tumor damage and may improve the

  17. Blood Outgrowth Endothelial Cells Increase Tumor Growth Rates and Modify Tumor Physiology: Relevance for Therapeutic Targeting

    Directory of Open Access Journals (Sweden)

    Kalpna Gupta

    2013-02-01

    Full Text Available Endothelial cell precursors from human peripheral blood have been shown to home to areas of neovascularization and may assist tumor growth by increasing or fortifying blood vessel growth. In the present study, the influence of these cells on tumor growth and physiology was investigated and the role of these cells as a therapeutic target or in determining treatment sensitivity was tested. After isolation from human blood and expansion in vitro, actively growing cells with verified endothelial phenotype (Blood Outgrowth Endothelial Cell, BOEC were injected i.v. into tumor bearing mice for three consecutive days. The growth rate was significantly enhanced in relatively small RERF human lung tumors (i.e., less than 150 mm3 grown in immunocompromised mice by an average of 1.5-fold while it had no effect when injections were given to animals bearing larger tumors. There were no signs of toxicity or unwanted systemic effects. We also observed evidence of increased perfusion, vessel number, response to 15 Gy radiation and oxygenation in RERF tumors of animals injected with BOECs compared to control tumors. In addition, FSaII murine fibrosarcoma tumors were found to grow faster upon injection of BOECs. When FSaII tumors were subjected to a partial thermal ablation treatment using high intensity focused ultrasound (HIFU there was consistently elevated detection of fluorescently labeled and i.v. injected endothelial precursors in the tumor when analyzed with optical imaging and/or histological preparations. Importantly, we also observed that BOECs treated with the novel anti-angiogenic peptide anginex in-vitro, show decreased proliferation and increased sensitivity to radiation. In vivo, the normal increase in FSaII tumor growth induced by injected BOECs was blunted by the addition of anginex treatment. It appears that endothelial precursors may significantly contribute to tumor vessel growth, tumor progression and/or repair of tumor damage and may improve

  18. Blood Outgrowth Endothelial Cells Increase Tumor Growth Rates and Modify Tumor Physiology: Relevance for Therapeutic Targeting

    International Nuclear Information System (INIS)

    Endothelial cell precursors from human peripheral blood have been shown to home to areas of neovascularization and may assist tumor growth by increasing or fortifying blood vessel growth. In the present study, the influence of these cells on tumor growth and physiology was investigated and the role of these cells as a therapeutic target or in determining treatment sensitivity was tested. After isolation from human blood and expansion in vitro, actively growing cells with verified endothelial phenotype (Blood Outgrowth Endothelial Cell, BOEC) were injected i.v. into tumor bearing mice for three consecutive days. The growth rate was significantly enhanced in relatively small RERF human lung tumors (i.e., less than 150 mm3) grown in immunocompromised mice by an average of 1.5-fold while it had no effect when injections were given to animals bearing larger tumors. There were no signs of toxicity or unwanted systemic effects. We also observed evidence of increased perfusion, vessel number, response to 15 Gy radiation and oxygenation in RERF tumors of animals injected with BOECs compared to control tumors. In addition, FSaII murine fibrosarcoma tumors were found to grow faster upon injection of BOECs. When FSaII tumors were subjected to a partial thermal ablation treatment using high intensity focused ultrasound (HIFU) there was consistently elevated detection of fluorescently labeled and i.v. injected endothelial precursors in the tumor when analyzed with optical imaging and/or histological preparations. Importantly, we also observed that BOECs treated with the novel anti-angiogenic peptide anginex in-vitro, show decreased proliferation and increased sensitivity to radiation. In vivo, the normal increase in FSaII tumor growth induced by injected BOECs was blunted by the addition of anginex treatment. It appears that endothelial precursors may significantly contribute to tumor vessel growth, tumor progression and/or repair of tumor damage and may improve the oxygenation

  19. Perpendicular Blood Vessel Seals Are Stronger Than Those Made at an Angle

    OpenAIRE

    Voegele, Aaron C.; Korvick, Donna L.; Gutierrez, Mario; Clymer, Jeffrey W.; Amaral, Joseph F.

    2013-01-01

    Vessel sealing devices effectively produce hemostatic seals with minimal thermal damage, but the strength of seals decreases as vessel diameter increases. Because vessels sealed at an angle to the vessel require a greater functional seal diameter than those sealed perpendicularly to the vessel, it was hypothesized that perpendicular seals would have comparably higher burst pressures. Ex vivo, porcine carotid arteries of nominal diameters of 5, 6, and 7 mm were sealed perpendicularly to and at...

  20. Angioblast Derived from ES Cells Construct Blood Vessels and Ameliorate Diabetic Polyneuropathy in Mice

    Directory of Open Access Journals (Sweden)

    Tatsuhito Himeno

    2015-01-01

    Full Text Available Background. Although numerous reports addressing pathological involvements of diabetic polyneuropathy have been conducted, a universally effective treatment of diabetic polyneuropathy has not yet been established. Recently, regenerative medicine studies in diabetic polyneuropathy using somatic stem/progenitor cell have been reported. However, the effectiveness of these cell transplantations was restricted because of their functional and numerical impairment in diabetic objects. Here, we investigated the efficacy of treatment for diabetic polyneuropathy using angioblast-like cells derived from mouse embryonic stem cells. Methods and Results. Angioblast-like cells were obtained from mouse embryonic stem cells and transplantation of these cells improved several physiological impairments in diabetic polyneuropathy: hypoalgesia, delayed nerve conduction velocities, and reduced blood flow in sciatic nerve and plantar skin. Furthermore, pathologically, the capillary number to muscle fiber ratios were increased in skeletal muscles of transplanted hindlimbs, and intraepidermal nerve fiber densities were ameliorated in transplanted plantar skin. Transplanted cells maintained their viabilities and differentiated to endothelial cells and smooth muscle cells around the injection sites. Moreover, several transplanted cells constructed chimeric blood vessels with recipient cells. Conclusions. These results suggest that transplantation of angioblast like cells induced from embryonic stem cells appears to be a novel therapeutic strategy for diabetic polyneuropathy.

  1. About a mechanism of the influence of shear stress for viscosity of the blood in vessels of small diameter

    OpenAIRE

    Катюхин, Лев Николаевич

    2014-01-01

    It is proposed a physiological and experimentally confirmed explanation of Fåhraeus-Lindqvist-effect in capillaries using the profile analyses of osmotic deformability of red blood cells. It was shown the dose-dependent change of the erythrocytes deformability in the stage of isotropic spheres after forming artificial water pores (nystatin) and occlusion (PbCl2) of available pores. The Sigma-effect reducing of hematocrit and viscosity in a shear flow of blood through the vessels of a small di...

  2. Evaluation of creep-fatigue crack growth for large-scale FBR reactor vessel

    International Nuclear Information System (INIS)

    Creep fatigue crack growth contributes to the failure of FBR reactor vessels in high temperature condition. In the design stage of reactor vessel, crack growth evaluation is very important to ensure the structural safety. In this study, creep-fatigue crack growth evaluation has been performed for the semi-elliptical surface cracks subjected to thermal loading by simplified JNC method. The thermal stress analysis of a large-scale FBR reactor vessel has been carried out for the load conditions by FINAS code. The distributions of axial, radial, hoop, and Von Mises stresses were obtained for the loading conditions. At the maximum point of the axial and hoop stress, the longitudinal and circumferential surface cracks (i.e. PTS, NDE and shallow cracks) were postulated. Using the maximum and minimum values of stresses, the creep-fatigue crack growth of the proposed cracks was simulated. The crack growth rate of circumferential cracks becomes greater than that of longitudinal cracks. Circumferential cracks become more hazardous than longitudinal cracks in the reactor. The total crack growth of the largest PTS crack is about 2mm after 427 cycles. The structural integrity of a large-scale reactor can be maintained for the plant life

  3. Three-dimensional multi-scale model of deformable platelets adhesion to vessel wall in blood flow.

    Science.gov (United States)

    Wu, Ziheng; Xu, Zhiliang; Kim, Oleg; Alber, Mark

    2014-08-01

    When a blood vessel ruptures or gets inflamed, the human body responds by rapidly forming a clot to restrict the loss of blood. Platelets aggregation at the injury site of the blood vessel occurring via platelet-platelet adhesion, tethering and rolling on the injured endothelium is a critical initial step in blood clot formation. A novel three-dimensional multi-scale model is introduced and used in this paper to simulate receptor-mediated adhesion of deformable platelets at the site of vascular injury under different shear rates of blood flow. The novelty of the model is based on a new approach of coupling submodels at three biological scales crucial for the early clot formation: novel hybrid cell membrane submodel to represent physiological elastic properties of a platelet, stochastic receptor-ligand binding submodel to describe cell adhesion kinetics and lattice Boltzmann submodel for simulating blood flow. The model implementation on the GPU cluster significantly improved simulation performance. Predictive model simulations revealed that platelet deformation, interactions between platelets in the vicinity of the vessel wall as well as the number of functional GPIbα platelet receptors played significant roles in platelet adhesion to the injury site. Variation of the number of functional GPIbα platelet receptors as well as changes of platelet stiffness can represent effects of specific drugs reducing or enhancing platelet activity. Therefore, predictive simulations can improve the search for new drug targets and help to make treatment of thrombosis patient-specific. PMID:24982253

  4. Single image correlation for blood flow mapping in complex vessel networks

    Science.gov (United States)

    Chirico, Giuseppe; Sironi, Laura; Bouzin, Margaux; D'Alfonso, Laura; Collini, Maddalena; Ceffa, Nicolo'G.; Marquezin, Cassia

    2015-05-01

    Microcirculation plays a key role in the maintenance and hemodynamics of tissues and organs also due to its extensive interaction with the immune system. A critical limitation of state-of-the-art clinical techniques to characterize the blood flow is their lack of the spatial resolution required to scale down to individual capillaries. On the other hand the study of the blood flow through auto- or cross-correlation methods fail to correlate the flow speed values with the morphological details required to describe an intricate network of capillaries. Here we propose to use a newly developed technique (FLICS, FLow Image Correlation Spectroscopy) that, by employing a single raster-scanned xy-image acquired in vivo by confocal or multi-photon excitation fluorescence microscopy, allows the quantitative measurement of the blood flow velocity in the whole vessel pattern within the field of view, while simultaneously maintaining the morphological information on the immobile structures of the explored circulatory system. Fluorescent flowing objects produce diagonal lines in the raster-scanned image superimposed to static morphological details. The flow velocity is obtained by computing the Cross Correlation Function (CCF) of the intensity fluctuations detected in pairs of columns of the image. The whole analytical dependence of the CCFs on the flow speed amplitude and the flow direction has been reported recently. We report here the derivation of approximated analytical relations that allows to use the CCF peak lag time and the corresponding CCF value, to directly estimate the flow speed amplitude and the flow direction. The validation has been performed on Zebrafish embryos for which the flow direction was changed systematically by rotating the embryos on the microscope stage. The results indicate that also from the CCF peak lag time it is possible to recover the flow speed amplitude within 13% of uncertainty (overestimation) in a wide range of angles between the flow and

  5. Creep crack growth in a reactor pressure vessel steel at 360 deg C

    Energy Technology Data Exchange (ETDEWEB)

    Rui Wu; Seitisleam, F.; Sandstroem, R. [Swedish Institute for Metals Research, Stockholm (Sweden)

    1998-12-31

    Plain creep (PC) and creep crack growth (CCG) tests at 360 deg C and post metallography were carried out on a low alloy reactor pressure vessel steel (ASTM A508 class 2) with different microstructures. Lives for the CCG tests were shorter than those for the PC tests and this is more pronounced for simulated heat affected zone microstructure than for the parent metal at longer lives. For the CCG tests, after initiation, the cracks grew constantly and intergranularly before they accelerated to approach rupture. The creep crack growth rate is well described by C*. The relations between reference stress, failure time and steady crack growth rate are presented for the CCG tests. It is demonstrated that the failure stress due to CCG is considerably lower than the yield stress at 360 deg C. Consequently, the CCG will control the static strength of a reactor vessel. (orig.) 17 refs.

  6. Creep crack growth in a reactor pressure vessel steel at 3600 C

    International Nuclear Information System (INIS)

    Plain creep (PC) and creep crack growth (CCG) tests at 360 deg C and post metallography were carried out on a low alloy reactor pressure vessel steel (ASTM A508 class 2) with different microstructures. Lives for the CCG tests were shorter than those for the PC tests and this is more pronounced for simulated heat affected zone microstructure than for the parent metal at longer lives. For the CCG tests, after initiation, the cracks grew constantly and intergranularly before they accelerated to approach rupture. The creep crack growth rate is well described by C*. The relations between reference stress, failure time and steady crack growth rate are presented for the CCG tests. It is demonstrated that the failure stress due to CCG is considerably lower than the yield stress at 360 deg C. Consequently, the CCG will control the static strength of a reactor vessel

  7. An Automated Graphical User Interface based System for the Extraction of Retinal Blood Vessels using Kirsch’s Template

    Directory of Open Access Journals (Sweden)

    Joshita Majumdar

    2015-06-01

    Full Text Available The assessment of Blood Vessel networks plays an important role in a variety of medical disorders. The diagnosis of Diabetic Retinopathy (DR and its repercussions including micro aneurysms, haemorrhages, hard exudates and cotton wool spots is one such field. This study aims to develop an automated system for the extraction of blood vessels from retinal images by employing Kirsch’s Templates in a MATLAB based Graphical User Interface (GUI. Here, a RGB or Grey image of the retina (Fundus Photography is used to obtain the traces of blood vessels. We have incorporated a range of Threshold values for the blood vessel extraction which would provide the user with greater flexibility and ease. This paper also deals with the more generalized implementation of various MATLAB functions present in the image processing toolbox of MATLAB to create a basic image processing editor with different features like noise addition and removal, image cropping, resizing & rotation, histogram adjust, separately viewing the red, green and blue components of a colour image along with brightness control, that are used in a basic image editor. We have combined both Kirsch’s Template and various MATLAB Algorithms to obtain enhanced images which would allow the ophthalmologist to edit and intensify the images as per his/her requirement for diagnosis. Even a non technical person can manage to identify severe discrepancies because of its user friendly appearance. The GUI contains very commonly used English Language viz. Load, Colour Contrast Panel, Image Clarity etc that can be very easily understood. It is an attempt to incorporate maximum number of image processing techniques under one GUI to obtain higher performance. Also it would provide a cost effective solution towards obtaining high definition and resolution images of blood vessel extracted Retina in economically backward regions where costly machine like OCT (Optical Coherence Tomography, MRI (Magnetic Resonance

  8. Molecular Dynamics Simulation of Soft Grains: Malaria-Infected Red Blood Cells Motion within Obstructed 2-D Capillary Vessel

    CERN Document Server

    Haris, Luman; Haryanto, Freddy; Viridi, Sparisoma

    2013-01-01

    Molecular dynamics has been widely used to numerically solve equation of motion of classical many-particle system. It can be used to simulate many systems including biophysics, whose complexity level is determined by the involved elements. Based on this method, a numerical model had been constructed to mimic the behaviour of malaria-infected red blood cells within capillary vessel. The model was governed by three forces namely Coulomb force, normal force, and Stokes force. By utilizing two dimensional four-cells scheme, theoretical observation was carried out to test its capability. Although the parameters were chosen deliberately, all of the quantities were given arbitrary value. Despite this fact, the results were quite satisfactory. Combined with the previous results, it can be said that the proposed model were sufficient enough to mimic the malaria-infected red blood cells motion within obstructed capillary vessel. Keywords: molecular dynamics, two-dimensional model, red-blood cell motion, malaria

  9. A study of the influence scan timing and depiction of blood vessel diameter in CE-3DMRA. Simulation by pulsatile flow

    International Nuclear Information System (INIS)

    In imaging using contrast-enhanced three-dimensional magnetic resonance angiography (CE-3DMRA), optimizing the delay time from the start of intravenous injection of contrast medium to the start of scanning has generally been an important concern when obtaining blood vessel images of good contrast. Recent methods of mechanically assessing the attainment of contrast medium injection include Smart-Prep and others. Another method is the Test Bolus, in which a small amount of contrast medium determines the timing of scan start, in quest of the time intensity curve. Because these methods are not necessarily satisfactory, the corrected method is used in clinical cases. In terms of how scan timing affects blood vessel depiction, no study has examined pulsatile flow, which is carried out by simulation. On the other hand, there are reports on data filling of k-space using imitation blood vessels on a computer and simple experimental equipment. This research examined experimentally blood vessel depiction according to scan timing and the diameter of blood vessels by using a systemic circulation simulator that incorporated hemodynamic circulation in which pulsatile flow is the same as that of a human body, using an artificial heart developed especially for MRI. It is thought that scan timing in CE-3DMRA affects the depiction of blood vessels for which the diameter of the blood vessel differs from the experimental result. Phase-encoding k-space data filling is the contrast-to-noise ratio (CNR) of each blood vessel irrespective of sequential and centric k-space ordering. The timing shift phenomenon, in which a blood vessel is so thin that the scan timing is overdue and shows a relatively high value, can occur. Moreover, that scan timing affects not only the diameter of a blood vessel but also depiction of the narrowing of a stenotic blood vessel or a branch blood vessel was demonstrated clinically and experimentally. Therefore, blood vessel depiction changes with scan timing, and

  10. Rate of growth of Pseudomonas fluorescens in donated blood.

    OpenAIRE

    Gibb, A. P.; Martin, K M; Davidson, G A; Walker, B.; Murphy, W G

    1995-01-01

    AIMS--To examine how delayed refrigeration of blood affects the growth of Pseudomonas fluorescens, one of the two most important causes of sepsis resulting from transfusion of contaminated blood. METHODS--Two donations of whole blood were each divided into three aliquots and inoculated with 5-10 cfu/ml of a P fluorescens strain from a case of transfusion associated sepsis. From each donation, one aliquot was placed at 4 degrees C, one was held at 20 degrees C for six hours prior to refrigerat...

  11. Expression of transforming growth factor beta 1-related signaling proteins in irradiated vessels

    International Nuclear Information System (INIS)

    Microvascular free tissue transfer is a standard method in head and neck reconstructive surgery. However, previous radiotherapy of the operative region is associated with an increased incidence in postoperative flap-related complications and complete flap loss. As transforming growth factor beta (TGF-β) 1 and galectin-3 are well known markers in the context of fibrosis and lectin-like oxidized low-density lipoprotein 1 (LOX-1) supports vascular atherosclerosis, the aim of this study was to evaluate the expression of TGF-β1 and related markers as well as LOX-1 in irradiated vessels. To evaluate the expression of galectin-3, Smad 2/3, TGF-β1, and LOX-1, 20 irradiated and 20 nonirradiated arterial vessels were used for immunohistochemical staining. We semiquantitatively assessed the ratio of stained cells/total number of cells (labeling index). Expression of galectin-3, Smad 2/3, and TGF-β1 was significantly increased in previously irradiated vessels compared with nonirradiated controls. Furthermore, LOX-1 was expressed significantly higher in irradiated compared with nonirradiated vessels. Fibrosis-related proteins like galectin-3, Smad 2/3, and TGF-β1 are upregulated after radiotherapy and support histopathological changes leading to vasculopathy of the irradiated vessels. Furthermore, postoperative complications in irradiated patients can be explained by increased endothelial dysfunction caused by LOX-1 in previously irradiated patients. Consequently, not only TGF-β1 but also galectin-3inhibitors may decrease complications after microsurgical tissue transfer. (orig.)

  12. Biological impact of vascular endothelial growth factor on vessel density and survival in multiple myeloma and plasmacytoma.

    Science.gov (United States)

    Swelam, Wael M; Al Tamimi, Dalal M

    2010-11-15

    We compared the differences in a number of angiogenesis-related immunohistochemical parameters, including microvascular density (MVD) and tumor cell activity, between multiple myeloma (MM) and solitary plasmacytoma (SP). Tissue sections from tumors of MM and SP were immunohistochemically stained and analyzed using ImageJ image analysis software for the expression of vascular endothelial growth factor (VEGF), VEGF receptors (Flt-1 and Flk-1), inducible nitric oxide (iNOS), and anti-apoptotic (Bcl-2) protein. Tumor tissues were cytologically graded as high-, intermediate-, or low-grade. Two pathologists determined the MVD of each section independently by recording the average number of CD34+ blood vessels in 500 unit fields. The arithmetic means for MVD were statistically analyzed using the Student's t-test and the significance level was calculated at P-value bimodal role that is mainly angiogenic in MM and tumorigenic, promoting tumor cell survival in SP. PMID:20709463

  13. Infrared tomography for diagnostic imaging of port wine stain blood vessels

    Energy Technology Data Exchange (ETDEWEB)

    Goodman, D. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    The objective of this work is the development of Infrared Tomography (IRT) for detecting and characterizing subsurface chromophores in human skin. Characterization of cutaneous chromophores is crucial for advances in the laser treatment of pigmented lesions (e.g., port wine stain birthmarks and tatoos). Infrared tomography (IRT) uses a fast infrared focal plane array (IR-FPA) to detect temperature rises in a substrate induced by pulsed radiation. A pulsed laser is used to produce transient heating of an object. The temperature rise, due to the optical absorption of the pulsed laser light, creates an increase in infrared emission which is measured by the IR-FPA. Although the application of IRT to image subsurface cracks due to metal fatigue is a topic of great interest in the aircraft industry, the application to image subsurface chromophores in biological materials is novel. We present an image recovery method based on a constrained conjugate gradient algorithm that has obtained the first ever high quality images of port wine blood vessels.

  14. Formation of an artificial blood vessel: adhesion force measurements with optical tweezers

    Science.gov (United States)

    Knoener, Gregor; Campbell, Julie H.; Heckenberg, Norman R.; Rubinsztein-Dunlop, Halina

    2004-10-01

    We are investigating the formation of a tissue capsule around a foreign body. This tissue capsule can be used as an autologous graft for the replacement of diseased blood vessels or for bypass surgery. The graft is grown in the peritoneal cavity of the recipient and the formation starts with the adhesion of cells to the foreign body. We identify the cell type and measure the adhesion of these cells to foreign materials using optical tweezers. Cell adhesion to macroscopic samples and microspheres is investigated. No difference in the adhesion force was measurable for polyethylene, silicon and Tygon on a scale accessible to optical tweezers. The density of adherent cells was found to vary strongly, being highest on polyethylene. The mean rupture forces for cell-microsphere adhesion ranged from 24 to 39 pN and changed upon preadsorption of bovine serum albumin. For plain microspheres, the highest mean rupture force was found for PMMA, which also showed the highest adhesion probability for the cell-microsphere interaction.

  15. Evaluation of local density enhancement of microcapsules in artificial blood vessel during exposure to focused ultrasound

    International Nuclear Information System (INIS)

    We have proposed a physical DDS (Drug Delivery System) which makes use of microcapsules of μm size, which may contain a specified drug and also are easily affected by ultrasound exposure near their resonant frequency, to release various kinds of medications. These capsules are easily detected and actuated by ultrasound. However, because of the diffusion of capsules after injection into human body, it was difficult to enhance the efficiency of drug delivery. Thus we have considered a method for controlling the density of capsules in flow which uses acoustic radiation force, which moves the capsules to balance flow resistance. We have experimented with trapping microcapsules or microbubbles in flow of an artificial blood vessel. We have evaluated the effect of radiation force by measuring the trapped area of capsules or bubbles for various frequencies, sound pressures, and exposure times of sinusoidal ultrasound. The trapped area of capsules or bubbles increased with sound pressure and exposure time, and decreased with frequency. From those results, we have derived optimal conditions for trapping the capsules or bubbles.

  16. Evaluation of local density enhancement of microcapsules in artificial blood vessel during exposure to focused ultrasound

    Science.gov (United States)

    Nakamoto, Ryusuke; Masuda, Kohji; Watarai, Nobuyuki; Taguchi, Yuto; Kato, Toshikazu; Yoshinaga, Takashi; Miyamoto, Yoshitaka; Chiba, Toshio

    2011-09-01

    We have proposed a physical DDS (Drug Delivery System) which makes use of microcapsules of μm size, which may contain a specified drug and also are easily affected by ultrasound exposure near their resonant frequency, to release various kinds of medications. These capsules are easily detected and actuated by ultrasound. However, because of the diffusion of capsules after injection into human body, it was difficult to enhance the efficiency of drug delivery. Thus we have considered a method for controlling the density of capsules in flow which uses acoustic radiation force, which moves the capsules to balance flow resistance. We have experimented with trapping microcapsules or microbubbles in flow of an artificial blood vessel. We have evaluated the effect of radiation force by measuring the trapped area of capsules or bubbles for various frequencies, sound pressures, and exposure times of sinusoidal ultrasound. The trapped area of capsules or bubbles increased with sound pressure and exposure time, and decreased with frequency. From those results, we have derived optimal conditions for trapping the capsules or bubbles.

  17. Knockdown of Zebrafish Blood Vessel Epicardial Substance Results in Incomplete Retinal Lamination

    Directory of Open Access Journals (Sweden)

    Yu-Ching Wu

    2014-01-01

    Full Text Available Cell polarity during eye development determines the normal retinal lamination and differentiation of photoreceptor cells in the retina. In vertebrates, blood vessel epicardial substance (Bves is known to play an important role in the formation and maintenance of the tight junctions essential for epithelial cell polarity. In the current study, we generated a transgenic zebrafish Bves (zbves promoter-EGFP zebrafish line to investigate the expression pattern of Bves in the retina and to study the role of zbves in retinal lamination. Immunostaining with different specific antibodies from retinal cells and transmission electron microscopy were used to identify the morphological defects in normal and Bves knockdown zebrafish. In normal zebrafish, Bves is located at the apical junctions of embryonic retinal neuroepithelia during retinogenesis; later, it is strongly expressed around inner plexiform layer (IPL and retinal pigment epithelium (RPE. In contrast, a loss of normal retinal lamination and cellular polarity was found with undifferentiated photoreceptor cells in Bves knockdown zebrafish. Herein, our results indicated that disruption of Bves will result in a loss of normal retinal lamination.

  18. CCL11-induced eosinophils inhibit the formation of blood vessels and cause tumor necrosis.

    Science.gov (United States)

    Xing, Yanjiang; Tian, Yijun; Kurosawa, Takamasa; Matsui, Sayaka; Touma, Maki; Yanai, Takanori; Wu, Qiong; Sugimoto, Kenkichi

    2016-06-01

    We previously demonstrated that IL-18 and CCL11 were highly expressed in an NFSA tumor cell line that showed limited angiogenesis and severe necrosis. However, IL-18 was not responsible for the immune cell accumulation and necrosis. Here, we attempted to clarify the relevance of CCL11 in angiogenesis and tumor formation. We established CCL11-overexpressing MS-K cell clones (MS-K-CCL11) to assess the role of CCL11 in immune cell accumulation and angiogenesis. The MS-K-CCL11 cells did not form tumors in mice. MS-K-CCL11-conditioned medium (CM) and recombinant CCL11 induced macrophage and eosinophil differentiation from bone marrow cells. The MS-K-CCL11-CM effectively recruited the differentiated eosinophils. Furthermore, the eosinophils damaged the MS-K, NFSA and endothelial cells in a dose-dependent manner. Administration of an antagonist of CCR3, a CCL11 receptor, to NFSA tumor-bearing mice restored the blood vessel formation and blocked the eosinophil infiltration into the NFSA tumors. Furthermore, other CCL11-overexpressing LM8 clones were established, and their tumor formation ability was reduced compared to the parental LM8 cells, accompanied by increased eosinophil infiltration, blockade of angiogenesis and necrosis. These results indicate that CCL11 was responsible for the limited angiogenesis and necrosis by inducing and attracting eosinophils in the tumors. PMID:27169545

  19. The effect of maternal smoke exposure on the ultrastructure of fetal peripheral blood vessels in the mouse.

    Science.gov (United States)

    Kaufmann, R C; Amankwah, K S; Weberg, A D

    1986-01-01

    Ultrastructural changes have been found in umbilical blood vessels, placental blood vessels, and peripheral blood vessels of human fetuses whose mothers smoked during pregnancy. This study was undertaken to determine if similar changes could be found in peripheral blood vessels of mice fetuses whose mothers were exposed to cigarette smoke during pregnancy. Breeding mice of the C57BL/KsJ strain were placed in a smoking box similar to that described by Younoszai and exposed to cigarette smoke intermittently. This produces carbon monoxide levels in the adult mice similar to that found in human adults smoking one pack of cigarettes per day. Similarly caged mice of the same strain were used as controls. The female mice were not removed from their cage from pre-conception time until after delivery. Upon delivery each pup was sacrificed via neck fracture and the entire pup was immersed in a solution of 2.5% glutaraldehyde in 0.1 M cacodylate buffer at pH 7.3. While still under solution, the rear leg muscles were dissected free, sliced, and immersed in the same preservative for four to five hours. They were then placed in fresh 2.5% glutaraldehyde mixture overnight. The tissues were post-fixed in osmium ferrocyanide and en-block stained with uranyl acetate in a graded series of alcohol. The tissues were infiltrated with and embedded in Spurr. Sections were taken via an ultramicrotome and post-stained with uranyl acetate and lead citrate. The sections were examined in a Philips 201 electron microscope at 60 KV. In the peripheral vessels of the fetuses from smoke-exposed mothers, endothelial blebbing (both surface-type and vacuole-type) was seen.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3783394

  20. Investigation of source-detector separation optimization for an implantable perfusion and oxygenation sensor for liver blood vessels

    Energy Technology Data Exchange (ETDEWEB)

    Baba, Justin S [ORNL; Akl, Tony [Texas A& M University; Cote, Gerard L. [Texas A& M University; Wilson, Mark A. [University of Pittsburgh School of Medicine, Pittsburgh PA; Ericson, Milton Nance [ORNL

    2011-01-01

    An implanted system is being developed to monitor transplanted liver health during the critical 7-10 day period posttransplantation. The unit will monitor organ perfusion and oxygen consumption using optically-based probes placed on both the inflow and outflow blood vessels, and on the liver parenchymal surface. Sensing probes are based on a 3- wavelength LED source and a photodiode detector. Sample diffuse reflectance is measured at 735, 805, and 940 nm. To ascertain optimal source-to-photodetector spacing for perfusion measurement in blood vessels, an ex vivo study was conducted. In this work, a dye mixture simulating 80% blood oxygen saturation was developed and perfused through excised porcine arteries while collecting data for various preset probe source-to-photodetector spacings. The results from this study demonstrate a decrease in the optical signal with decreasing LED drive current and a reduction in perfusion index signal with increasing probe spacing. They also reveal a 2- to 4-mm optimal range for blood vessel perfusion probe source-to-photodetector spacing that allows for sufficient perfusion signal modulation depth with maximized signal to noise ratio (SNR). These findings are currently being applied to guide electronic configuration and probe placement for in vivo liver perfusion porcine model studies.

  1. Malformation of certain brain blood vessels caused by TCDD activation of Ahr2/Arnt1 signaling in developing zebrafish

    International Nuclear Information System (INIS)

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) causes various signs of toxicity in early life stages of vertebrates through activation of the aryl hydrocarbon receptor (AHR). The AHR also plays important roles in normal development in mice, and AHR-/- mice show abnormal development of vascular structures in various blood vessels. Our previous studies revealed that Ahr type 2 (Ahr2) activation by TCDD and β-naphthoflavone (BNF) caused a significant decrease in blood flow in the dorsal midbrain of zebrafish embryos. Here we report effects of TCDD exposure on the morphology of some blood vessels in the head of developing zebrafish. TCDD caused concentration-dependent anatomical rearrangements in the shape of the prosencephalic artery in zebrafish larvae. In contrast, no major vascular defects were recognized in the trunk and tail regions following exposure to TCDD at least at the concentrations used. Essentially, the same observations were also confirmed in BNF-exposed larvae. Knock-down of either Ahr2 or Ahr nuclear translocator type 1 (Arnt1) by morpholino oligonucleotides (MOs) protected larvae against abnormal shape of the prosencephalic artery caused by TCDD and BNF. On the other hand, knock-down of Ahr2 or Arnt1 in vehicle-exposed zebrafish larvae had no clear effect on morphology of the prosencephalic artery or trunk vessels. Ascorbic acid, an antioxidant, protected against the TCDD-induced decrease in blood flow through the prosencephalic artery, but not the abnormal morphological changes in the shape of this artery. These results indicate that activation of Ahr2/Arnt1 pathway by TCDD and BNF affects the shape of certain blood vessels in the brain of developing zebrafish.

  2. Malformation of certain brain blood vessels caused by TCDD activation of Ahr2/Arnt1 signaling in developing zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Teraoka, Hiroki, E-mail: hteraoka@rakuno.ac.jp [School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501 (Japan); Ogawa, Akira [School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501 (Japan); Kubota, Akira [School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501 (Japan); Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA (United States); Stegeman, John J. [Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA (United States); Peterson, Richard E. [School of Pharmacy, University of Wisconsin, Madison, WI (United States); Hiraga, Takeo [School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501 (Japan)

    2010-08-15

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) causes various signs of toxicity in early life stages of vertebrates through activation of the aryl hydrocarbon receptor (AHR). The AHR also plays important roles in normal development in mice, and AHR{sup -/-} mice show abnormal development of vascular structures in various blood vessels. Our previous studies revealed that Ahr type 2 (Ahr2) activation by TCDD and {beta}-naphthoflavone (BNF) caused a significant decrease in blood flow in the dorsal midbrain of zebrafish embryos. Here we report effects of TCDD exposure on the morphology of some blood vessels in the head of developing zebrafish. TCDD caused concentration-dependent anatomical rearrangements in the shape of the prosencephalic artery in zebrafish larvae. In contrast, no major vascular defects were recognized in the trunk and tail regions following exposure to TCDD at least at the concentrations used. Essentially, the same observations were also confirmed in BNF-exposed larvae. Knock-down of either Ahr2 or Ahr nuclear translocator type 1 (Arnt1) by morpholino oligonucleotides (MOs) protected larvae against abnormal shape of the prosencephalic artery caused by TCDD and BNF. On the other hand, knock-down of Ahr2 or Arnt1 in vehicle-exposed zebrafish larvae had no clear effect on morphology of the prosencephalic artery or trunk vessels. Ascorbic acid, an antioxidant, protected against the TCDD-induced decrease in blood flow through the prosencephalic artery, but not the abnormal morphological changes in the shape of this artery. These results indicate that activation of Ahr2/Arnt1 pathway by TCDD and BNF affects the shape of certain blood vessels in the brain of developing zebrafish.

  3. Analysis by NASA's VESGEN Software of Retinal Blood Vessels Before and After 70-Day Bed Rest: A Retrospective Study

    Science.gov (United States)

    Raghunandan, Sneha; Vyas, Ruchi J.; Vizzeri, Gianmarco; Taibbi, Giovanni; Zanello, Susana B.; Ploutz-Snyder, Robert; Parsons-Wingerter, Patricia A.

    2016-01-01

    Significant risks for visual impairment associated with increased intracranial pressure (VIIP) are incurred by microgravity spaceflight, especially long-duration missions. Impairments include decreased near visual acuity, posterior globe flattening, choroidal folds, optic disc edema and cotton wool spots. We hypothesize that microgravity-induced fluid shifts result in pathological changes within the retinal blood vessels that precede development of visual and other ocular impairments. Potential contributions of retinal vascular remodeling to VIIP etiology are therefore being investigated by NASAs innovative VESsel GENeration Analysis (VESGEN) software for two studies: (1) head-down tilt in human subjects before and after 70 days of bed rest, and (2) U.S. crew members before and after ISS missions. VESGEN analysis in previous research supported by the US National Institutes of Health identified surprising new opportunities to regenerate retinal vessels during early-stage, potentially reversible progression of the visually impairing and blinding disease, diabetic retinopathy.

  4. The immunohistochemical peculiarities of blood vessels during different forms of cancer of mammary glands

    Directory of Open Access Journals (Sweden)

    Khidirov E.A.

    2010-12-01

    Full Text Available The aim of this investigation was to study the peculiarities of the cancer of the mammary gland depending on its histogenesis, histological form, character of growth, degree of malignancy and stages of development on the postop-erational material. As a research material 72 cases of the cancer of the mammary gland have served. The level of the expression of marker CD 31 depending on the degree, zone and form of the cancer of the mammary gland was studied by immunohystochemical method. The results of the research have shown that the peripheric zone of the cancer intensively supplied by the vessels of type of capillaries, in comparison with the central zone there is not many gigantic capillaries of type of sinusoids surrounded with tumoral cells, but is a lot of cells marked an angiogenesis marker - CD 31. Number of marker CD 31 in the cancer tissue changes depending on degree of differentiation of the tumoral tissue, it increases according to degree of malignancy of cancer. For example, monoclon CD 31 in the tumoral cells more intensively in medullary forms of the cancer than in tubular forms

  5. Nonparenchymal cells cultivated from explants of fibrotic liver resemble endothelial and smooth muscle cells from blood vessel walls

    International Nuclear Information System (INIS)

    Tissue specimens from human fibrotic liver obtained by needle biopsy were cultured. Two cell types emerged from the tissue explants. From their morphology and biosynthetic products they resembled smooth muscle cells and endothelial cells from blood vessel walls. In the endothelial cells, factor VIII-associated protein was demonstrated by indirect immunofluorescence. Synthesis of collagen types I and III, basement membrane collagen types IV and V, and fibronectin by both cell types was observed by immunofluorescence microscopy. Homogeneous cultures of smooth muscle cells were observed in subcultures. After incubation with [14C]glycine, collagen was isolated and characterized by CM cellulose chromatography, and consisted mainly of types I and III. These data suggest involvement of mesenchymal cells in hepatic fibrosis; they presumably originate from blood vessel or sinusoidal walls

  6. NUMERICAL SIMULATION OF HEMODYNAMICS IN THE HOST BLOOD VESSEL AND MICROVASCULAR NETWORK GENERATED FROM TUMOR-INDUCED ANGIOGENESIS

    Institute of Scientific and Technical Information of China (English)

    ZHAO Gai-ping; WU Jie; XU Shi-xiong; COLLINS M.W.; JIANG Yu-ping; WANG Jian

    2006-01-01

    Numerical simulation of hemodynamics under the combined effects of both the host blood vessel and the microvascular network,which is based on a 2-D tumor inside and outside vascular network generated from a discrete mathematical model of tumor-induced angiogenesis, is performed systemically. And a "microvascular network-transport across microvascular network-flow in interstitium" model is developed to study the flow in solid tumor. Simulations are carried out to examine the effects of the variations of the inlet Reynolds number in the host blood vessel, the hydraulic conductivity of the microvascular wall, and interstitial hydraulic conductivity coefficient on the fluid flow in tumor microcirculation. The results are consistent with data obtained in terms of physiology. These results may provide some theoretical references and the bases for further clinical experimental research.

  7. Imaging functional blood vessels by the laser speckle imaging (LSI) technique using Q-statistics of the generalized differences algorithm.

    Science.gov (United States)

    Ansari, Mohammad Zaheer; Cabrera, Humberto; Ramírez-Miquet, Evelio E

    2016-09-01

    In this work, we report about q statistics concept to improve the performance of generalized differences algorithm based on intensity histogram for imaging functional blood vessel structures in a rodent window chamber of a mice. The method uses the dynamic speckle signals obtained by transilluminating the rodent window chamber to create activity maps of vasculatures. The proposed method of generalized differences with q statistics (GDq) is very sensitive to the values of defined parameters such as: camera exposure time, the q value and the camera frame number. Appropriate choice of q values enhances the visibility (contrast) of functional blood vessels but at the same time without sacrificing the spatial resolution, which is of utmost importance for in-vivo vascular imaging. PMID:27154269

  8. Sinusoïdal flow of blood in a cylindrical deformable vessel exposed to an external magnetic field

    Science.gov (United States)

    Drochon, Agnès

    2016-03-01

    The present work provides an analytical solution for the Sinusoïdal flow of blood in a cylindrical elastic vessel exposed to an external magnetic field. The vessel is supposed to have non-conducting walls and the induced electric and magnetic fields are neglected. In other words, the well-known calculation of Womersley is revisited through the inclusion of the Lorentz force in the Navier-Stokes equations. A dispersion equation is obtained. This equation admits two types of solutions: the Young waves (mainly associated with radial deformation of the vessel) and the Lamb waves (mainly associated with longitudinal displacements in the vessel wall). It is demonstrated that the external magnetic field has an influence on the wave celerities, on the fluid velocity profiles, and on the wall displacements. It tends to reduce the blood flow and flatten the velocity profile, in the case of Young waves. The pulsatile character of the flow is also dampened. However, these effects become detectable for high values of the Hartmann number (M > 4, corresponding to B0 > 36 T with numerical data pertaining to large human arteries) and remain negligible in the context of magnetic resonance imaging (B0 ≤ 3 T, or even 7 T).

  9. Relation of Blood Pressure to Retinal Vessel Diameter in Type 1 Diabetes Mellitus

    Science.gov (United States)

    Klein, Ronald; Myers, Chelsea E.; Klein, Barbara E. K.; Zinman, Bernard; Gardiner, Robert; Suissa, Samy; Sinaiko, Alan R.; Donnelly, Sandra M.; Goodyer, Paul; Strand, Trudy; Mauer, Michael

    2009-01-01

    Objective To examine the relationship of blood pressure (BP) and use of angiotensin receptor blocker (ARB) or angiotensin converting enzyme inhibitor (ACEI) to retinal vessel diameter in normotensive, normoalbuminuric persons with type 1 diabetes mellitus (T1DM). Design Randomized controlled clinical trial. Participants Persons with T1DM and gradable fundus photographs both at baseline (n=147) and 5-year follow-up (n=124). Methods Clinic and 24-hour ambulatory BPs (ABP) were measured. Retinal arteriolar and venular diameters were measured using a computer-assisted technique. Individual arteriolar and venular measurements were combined into summary indices that reflect the average retinal arteriolar (central retinal arteriolar equivalent [CRAE]) and venular (central retinal venular equivalent [CRVE]) diameter of an eye, respectively. Main Outcome Measures CRAE and CRVE. Results While controlling for age, study site, glycosylated hemoglobin and ambulatory pulse rate, daytime ambulatory systolic (-0.29 μm effect per 1mmHg, P=.02) and daytime ambulatory diastolic (-0.44 μm effect per 1mmHg, P=.04), nighttime ambulatory systolic (-0.27 μm effect per 1mmHg, P=.03), and 24-hour ambulatory systolic BP (-0.31 μm effect per 1mmHg, P=.03) were cross-sectionally associated with a smaller CRAE. While controlling for age, study site, glycosylated hemoglobin, ambulatory pulse rate and baseline CRAE, no BP measure was associated with a change in CRAE or CRVE over 5 years of follow-up. Treatment with losartan or enalapril was not associated with a statistically significant change in CRAE or CRVE. Conclusions ACEI or ARB therapy does not affect retinal arteriolar or venular diameter in normotensive persons with T1DM. PMID:20142543

  10. BLOOD VESSELS IN GANGLIA IN HUMAN ESOPHAGUS MIGHT EXPLAIN THE HIGHER FREQUENCY OF MEGAESOPHAGUS COMPARED WITH MEGACOLON

    Directory of Open Access Journals (Sweden)

    Sheila Jorge Adad

    2014-12-01

    Full Text Available This study aimed to determine the existence of blood vessels within ganglia of the myenteric plexus of the human esophagus and colon. At necropsy, 15 stillborns, newborns and children up to two years of age, with no gastrointestinal disorders, were examined. Rings of the esophagus and colon were analyzed and then fixed in formalin and processed for paraffin. Histological sections were stained by hematoxylin-eosin, Giemsa and immunohistochemistry for the characterization of endothelial cells, using antibodies for anti-factor VIII and CD31. Blood vessels were identified within the ganglia of the myenteric plexus of the esophagus, and no blood vessels were found in any ganglia of the colon. It was concluded that the ganglia of the myenteric plexus of the esophagus are vascularized, while the ganglia of the colon are avascular. Vascularization within the esophageal ganglia could facilitate the entrance of infectious agents, as well as the development of inflammatory responses (ganglionitis and denervation, as found in Chagas disease and idiopathic achalasia. This could explain the higher frequency of megaesophagus compared with megacolon.

  11. 3D MR sequence capable of simultaneous image acquisitions with and without blood vessel suppression: Utility in diagnosing brain metastases

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Kazufumi; Hiwatashi, Akio; Togao, Osamu; Yamashita, Koji; Yoshiura, Takashi; Honda, Hiroshi [Kyushu University, Department of Clinical Radiology, Graduate School of Medical Sciences, Fukuoka (Japan); Yoneyama, Masami [Yaesu Clinic, Chuo-ku, Tokyo (Japan); Obara, Makoto [Philips Electronics Japan, Minato-ku, Tokyo (Japan); Kishimoto, Junji [Kyushu University, Department of Research and Development of Next Generation Medicine, Faculty of Medical Sciences, Higashi-ku, Fukuoka (Japan)

    2015-04-01

    Volume isotropic simultaneous interleaved bright- and black-blood examination (VISIBLE) is a recently developed 3D MR sequence that provides simultaneous acquisitions of images with blood vessel suppression (Black) and images without it (Bright). Our purpose was to evaluate the usefulness of VISIBLE in detecting brain metastases. This prospective study included patients with suspected brain metastasis imaged with both VISIBLE and MPRAGE. From a data set, we compared the number of visualized blood vessels and the lesion-to-normal contrast-to-noise ratio (CNR) in 60 patients. We also performed an observer test to compare their diagnostic performance with VISIBLE, MPRAGE and only Black in 34 patients. Diagnostic performance was evaluated using a figure of merit (FOM), sensitivity, false-positive results per case (FPs/case) and reading time. The number of vessels was significantly fewer in Black compared to MPRAGE and Bright (P < 0.0001). CNR was significantly higher with both Black and Bright than with MPRAGE (P < 0.005). In the observer test, significantly higher sensitivity (P < 0.0001) and FOM (P < 0.0001), significantly shorter reading time (P = 0.0001) and similar FPs/case were achieved with VISIBLE compared to MPRAGE. Compared to only Black, VISIBLE resulted in comparable sensitivity, but significantly fewer FPs/case (P = 0.0008). VISIBLE can improve radiologists' diagnostic performance for brain metastasis. (orig.)

  12. Effects of temperature on corrosion fatigue crack growth of pressure vessel steels in PWR coolant

    International Nuclear Information System (INIS)

    This paper presents experimental results concerning crack propagation rates in A508-III pressure vessel steel (medium sulphur content) exposed to PWR primary water at temperatures between 130 and 290 C. The results indicate that the greatest increase in corrosion fatigue crack growth rate occurs at temperatures in the range 150 to 200 C. Under these conditions, there was a marked change in the appearance of the fracture surface, with extensive micro-branching of the crack front and occasional bifurcation of the whole crack path. In contrast, at 290 C, the fracture surface is smoother, similar to that due to inert fatigue. The implication of these observations for assessment of the pressure vessel integrity, is examined. 14 refs., 15 figs., 3 tabs

  13. Experimental and numerical investigations of stable crack growth of axial surface flaws in a pressure vessel

    International Nuclear Information System (INIS)

    In connection with the problem of the transferability of parameters obtained experimentally with the help of fracture-mechanical test specimens and used for the initiation and the stable propagation of cracks in cases of pulsating stress and of the elasto-plastic behaviour of construction components, a pressure vessel with an inside diameter of 1500 mm, a cylindrical length of 3000 mm and a wall thickness of 40 mm was hydraulically loaded with the help of internal pressure in the first stage, to attain an average crack growth of 1 mm at Δ a ≅, the loading taking place at about 21deg C. This stress-free annealed vessel exhibited an axial semielliptical vibration-induced surface crack about 181 mm long and 20 mm deep, as a test defect, in a welded circular blank made of the steel 20MnMoNi 55. The fractographic analysis of the first stable crack revealed that its growth rate of Δa was highest in the area of transition from the weak to the strong bend of the crack front (55deg m/σv (average principal stress: σm, Mises' reference stress: σvv). A comparison of the experimental with the numerical results from the first stable crack shows that the local stable crack growth Δa cannot be calculated solely with reference to J, because Δa appears to depend essentially on the quotient σm/σv. (orig./MM)

  14. In-vivo imaging of blood flow in human retinal vessels using color Doppler optical coherence tomography

    Science.gov (United States)

    Yazdanfar, Siavash; Rollins, Andrew M.; Izatt, Joseph A.

    1999-04-01

    Quantification of retinal blood flow may lead to a better understanding of the progression and treatment of several ocular disorders, including diabetic retinopathy, age- related macular degeneration, and glaucoma. Current techniques, such as fluorescein angiography and laser Doppler velocimetry are limited, failing to provide sufficient information to the clinician. Color Doppler optical coherence tomography (CDOCT) is a novel technique using coherent heterodyne detection for simultaneous cross- sectional imaging of tissue microstructure and blood flow. This technique is capable of high spatial and velocity resolution imaging in highly scattering media. We implemented CDOCT for retinal blood flow mapping in human subjects. No dilation of the pupil was necessary. CDOCT is demonstrated for determining bidirectional flow in sub- 100micrometers diameter vessels in the retina. Additionally, we calculated Doppler broadening using the variance of depth- resolved spectra to identify regions with large velocity gradients within the Xenopus heart. This technique may be useful in quantifying local tissue perfusion in highly vascular retinal tissue.

  15. Subcritical crack growth in the ligament between the instrumentation rods of the BBR pressure vessel bottom

    International Nuclear Information System (INIS)

    A fracture mechanics fatigue analysis is made for an assumed crack emanating from the bore of an instrumentation rod. This assumed crack has partially penetrated the Inconel buttering of the 22 Ni Mo Cr 37 on which the structural Inconel welds are laid. Our analysis shows that the assumed crack could only penetrate 26% of the remaining ligament of the Inconel structural weld as a result of the fatigue crack growth during the entire operating life of the pressure vessel. Therefore a leak caused by a flaw missed during pre-service and in-service non-destructive testing can be excluded. (author)

  16. The blood-tendon barrier: identification and characterisation of a novel tissue barrier in tendon blood vessels.

    Science.gov (United States)

    Lehner, C; Gehwolf, R; Ek, J C; Korntner, S; Bauer, H; Bauer, H C; Traweger, A; Tempfer, H

    2016-01-01

    Tissue barriers function as "gate keepers" between different compartments (usually blood and tissue) and are formed by specialised membrane-associated proteins, localising to the apicolateral plasma membrane domain of epithelial and endothelial cells. By sealing the paracellular space, the free diffusion of solutes and molecules across epithelia and endothelia is impeded. Thereby, tissue barriers contribute to the establishment and maintenance of a distinct internal and external environment, which is crucial during organ development and allows maintenance of an organ-specific homeostatic milieu. So far, various epithelial and endothelial tissue barriers have been described, including the blood-brain barrier, the blood-retina barrier, the blood-testis barrier, the blood-placenta barrier, and the cerebrospinal fluid (CSF)-brain barrier, which are vital for physiological function and any disturbance of these barriers can result in severe organ damage or even death. Here, we describe the identification of a novel barrier, located in the vascular bed of tendons, which we term the blood-tendon barrier (BTB). By using immunohistochemistry, transmission electron microscopy, and tracer studies we demonstrate the presence of a functional endothelial barrier within tendons restricting the passage of large blood-borne molecules into the surrounding tendon tissue. We further provide in vitro evidence that the BTB potentially contributes to the creation of a distinct internal tissue environment impacting upon the proliferation and differentiation of tendon-resident cells, effects which might be fundamental for the onset of tendon pathologies. PMID:27227787

  17. Nestin(+ tissue-resident multipotent stem cells contribute to tumor progression by differentiating into pericytes and smooth muscle cells resulting in blood vessel remodeling

    Directory of Open Access Journals (Sweden)

    DianaKlein

    2014-06-01

    Full Text Available Tumor vessels with resistance to anti-angiogenic therapy are characterized by the normalization of the vascular structures through integration of mature pericytes and smooth muscle cells (SMC into the vessel wall, a process termed vessel stabilization. Unfortunately, stabilization-associated vascular remodeling can result in reduced sensitivity to subsequent anti-angiogenic therapy. We show here that blockade of VEGF by bevacizumab induces stabilization of angiogenic tumor blood vessels in human tumor specimen by recruiting Nestin-positive cells, whereas mature vessels down-regulated Nestin-expression. Using xenograft tumors growing on bone-marrow (BM chimera of C57Bl/6 wildtype and Nestin-GFP transgenic mice we show for first time that Nestin(+ cells inducing the maturation of tumor vessels do not originate from the BM but presumably reside within the adventitia of adult blood vessels. Complementary ex vivo experiments using explants of murine aortas revealed that Nestin(+ multipotent stem cells (MPSCs are mobilized from their niche and differentiated into pericytes and SMC through the influence of tumor-cell secreted factors. We conclude that tissue-resident Nestin(+ cells are more relevant than BM-derived cells for vessel stabilization and therefore have to be considered in future strategies for anti-angiogenic therapy. The identification of proteins mediating recruitment or differentiation of local Nestin(+ cells with potential stem cell character to angiogenic blood vessels may allow the definition of new therapeutic targets to reduce tumor resistance against anti-angiogenic drugs.

  18. Fracture toughness and crack growth resistance of pressure vessel plate and weld metal steels

    International Nuclear Information System (INIS)

    Compact tension specimens were used to measure the initiation fracture toughness and crack growth resistance of pressure vessel steel plates and submerged arc weld metal. Plate test specimens were manufactured from four different casts of steel comprising: aluminium killed C-Mn-Mo-Cu and C-Mn steel and two silicon killed C-Mn steels. Unionmelt No. 2 weld metal test specimens were extracted from welds of double V butt geometry having either the C-Mn-Mo-Cu steel (three weld joints) or one particular silicon killed C-Mn steel (two weld joints) as parent plate. A multiple specimen test technique was used to obtain crack growth data which were analysed by simple linear regression to determine the crack growth resistance lines and to derive the initiation fracture toughness values for each test temperature. These regression lines were highly scattered with respect to temperature and it was very difficult to determine precisely the temperature dependence of the initiation fracture toughness and crack growth resistance. The data were re-analysed, using a multiple linear regression method, to obtain a relationship between the materials' crack growth resistance and toughness, and the principal independent variables (temperature, crack growth, weld joint code and strain ageing). (author)

  19. A micro-scale simulation of red blood cell passage through symmetric and asymmetric bifurcated vessels

    CERN Document Server

    Wang, Tong; Xing, Zhongwen

    2016-01-01

    Blood exhibits a heterogeneous nature of hematocrit, velocity, and effective viscosity in microcapillaries. Microvascular bifurcations have a significant influence on the distribution of the blood cells and blood flow behavior. This paper presents a simulation study performed on the two-dimensionalmotions and deformation of multiple red blood cells in microvessels with diverging and converging bifurcations. Fluid dynamics and membrane mechanics were incorporated. Effects of cell shape, hematocrit, and deformability of the cell membrane on rheological behavior of the red blood cells and the hemodynamics have been investigated. It was shown that the blood entering the daughter branch with a higher flow rate tended to receive disproportionally more cells. The results also demonstrate that red blood cells in microvessels experienced lateral migration in the parent channel and blunted velocity profiles in both straight section and daughter branches, and this effect was influenced by the shape and the initial posit...

  20. Effects of electrical stunning frequency and voltage combinations on the presence of engorged blood vessels in goose liver.

    Science.gov (United States)

    Turcsán, Zs; Varga, L; Szigeti, J; Turcsán, J; Csurák, I; Szalai, M

    2003-11-01

    The purpose of this study was to investigate the influence of nine electrical stunning methods using various frequency and voltage combinations on the occurrence of engorged blood vessels in goose liver. Two hundred seventy Gourmaud geese (liver-type line SI 14) were slaughtered at 12 wk of age, in groups of 90 at three different times. Thirty birds each were subjected to one of the nine stunning methods. Neck cutting was performed immediately after stunning. The duration of exsanguination was 11 min. After completion of bleeding, the birds were scalded, defeathered manually, and kept refrigerated. At 1 d postmortem, the carcasses were eviscerated and cut up. From the slaughterhouse, the livers chilled in ice were transported to the cannery where they were weighed and graded at 2 d postmortem and were further processed. All of the veins and capillaries full of blood were removed from livers, because their presence was a hazard to product quality by causing discoloration of the canned liver, and the percentage of liver weight loss was then determined. The loss in liver weight due to removal of engorged blood vessels was reduced (P electrical stunning of liver geese might have considerable commercial advantages. PMID:14653479

  1. Ultrafine Fibrous Membranes by Coaxial Electrospinning for Artificial Blood Vessel%同轴电纺超细纤维膜构建人工血管材料

    Institute of Scientific and Technical Information of China (English)

    曹文轩; 张红; 袁晓燕

    2011-01-01

    以右旋糖酐(DEX)为芯、聚乙二醇-b-聚(L-丙交酯-co-ε-己内酯)(PELCL)为壳,采用同轴电纺技术制备DEX/PELCL超细纤维膜.在该电纺纤维内芯分别负载血管内皮生长因子(VEGF)和血小板衍生生长因子(PDGF-bb),并以此构建双层超细纤维膜人工血管支架.28 d的释放结果表明,VEGF和PDGF-bb 均表现出突释现象,含有肝素的VEGF样品释放量有所下降.大鼠腹主动脉移植实验结果表明,载有VEGF和PDGFbb的超细纤维膜可以用于构建双层人工血管.%Core/shell ultrafine fibers, with dextran(DEX) and poly(ethylene glycol)-b-poly(L-lactide-co-εcaprolactone) (PELCL) as the core and shell, respectively, were prepared by coaxial electrospinning.Double-layered ultraline fibrous tubes of the coaxial-electrospun DEX/PELCL fiberswere constructed for application as artificial blood vessel by loading vascular endothelial growth factor (VEGF) and platelet derived growth factor-bb( PDGF-bb), respectively in the fiber core. The in vitro releasing results of 28 d indicated that initial burst release occurred for both VEGF and PDGF-bb. The in vivo implantation in abdomen aorta of a rat model showed that the double-layered fibrous tubes loading VEGF and PDGF-bb could be potential used as artificial blood vessels.

  2. Effect of blood vessel segmentation on the outcome of electroporation-based treatments of liver tumors.

    Directory of Open Access Journals (Sweden)

    Marija Marčan

    Full Text Available Electroporation-based treatments rely on increasing the permeability of the cell membrane by high voltage electric pulses applied to tissue via electrodes. To ensure that the whole tumor is covered with sufficiently high electric field, accurate numerical models are built based on individual patient anatomy. Extraction of patient's anatomy through segmentation of medical images inevitably produces some errors. In order to ensure the robustness of treatment planning, it is necessary to evaluate the potential effect of such errors on the electric field distribution. In this work we focus on determining the effect of errors in automatic segmentation of hepatic vessels on the electric field distribution in electroporation-based treatments in the liver. First, a numerical analysis was performed on a simple 'sphere and cylinder' model for tumors and vessels of different sizes and relative positions. Second, an analysis of two models extracted from medical images of real patients in which we introduced variations of an error of the automatic vessel segmentation method was performed. The results obtained from a simple model indicate that ignoring the vessels when calculating the electric field distribution can cause insufficient coverage of the tumor with electric fields. Results of this study indicate that this effect happens for small (10 mm and medium-sized (30 mm tumors, especially in the absence of a central electrode inserted in the tumor. The results obtained from the real-case models also show higher negative impact of automatic vessel segmentation errors on the electric field distribution when the central electrode is absent. However, the average error of the automatic vessel segmentation did not have an impact on the electric field distribution if the central electrode was present. This suggests the algorithm is robust enough to be used in creating a model for treatment parameter optimization, but with a central electrode.

  3. Impact of lymphatic and/or blood vessel invasion in stage II gastric cancer

    Directory of Open Access Journals (Sweden)

    Chun-Yan Du

    2012-01-01

    Full Text Available AIM: To determine the prognostic value of lymphatic and/or blood vessel invasion (LBVI in patients with stage II gastric cancer. METHODS: From January 2001 to December 2006, 487 patients with histologically confirmed primary gastric adenocarcinoma were diagnosed with stage II gastric cancer according to the new 7th edition American Joint Committee on Cancer stage classification at the Department of Gastric Cancer and Soft Tissue Surgery, Fudan University Shanghai Cancer Center. All patients underwent curative gastrectomy with standard lymph node (LN dissection. Fifty-one patients who died in the postoperative period, due to various complications or other conditions, were excluded. Clinicopathological findings and clinical outcomes were analyzed. Patients were subdivided into four groups according to the status of LBVI and LN metastases. These four patient groups were characterized with regard to age, sex, tumor site, pT category, tumor grading and surgical procedure (subtotal resection vs total resection, and compared for 5-year overall survival by univariate and multivariate analysis. RESULTS: The study was composed of 320 men and 116 women aged 58.9 ± 11.5 years (range: 23-88 years. The 5-year overall survival rates were 50.7% and the median survival time was 62 mo. Stage IIa cancer was observed in 334 patients, including 268 T3N0, 63 T2N1, and three T1N2, and stage IIb was observed in 102 patients, including 49 patients T3N1, 51 T2N2, one T1N3, and one T4aN0. The incidence of LBVI was 28.0% in stage II gastric cancer with 19.0% (51/269 and 42.5% (71/167 in LN-negative and LN-positive patients, respectively. In 218 patients (50.0%, there was neither a histopathologically detectable LBVI nor LN metastases (LBVI−/LN−, group I; in 51 patients (11.7%, LBVI with no evidence of LN metastases was detected (LBVI+/LN−, group II. In 167 patients (38.3%, LN metastases were found. Among those patients, LBVI was not determined in 96 patients (22

  4. Failure of collateral blood flow is associated with infarct growth in ischemic stroke.

    Science.gov (United States)

    Campbell, Bruce C V; Christensen, Søren; Tress, Brian M; Churilov, Leonid; Desmond, Patricia M; Parsons, Mark W; Barber, P Alan; Levi, Christopher R; Bladin, Christopher; Donnan, Geoffrey A; Davis, Stephen M

    2013-08-01

    Changes in collateral blood flow, which sustains brain viability distal to arterial occlusion, may impact infarct evolution but have not previously been demonstrated in humans. We correlated leptomeningeal collateral flow, assessed using novel perfusion magnetic resonance imaging (MRI) processing at baseline and 3 to 5 days, with simultaneous assessment of perfusion parameters. Perfusion raw data were averaged across three consecutive slices to increase leptomeningeal collateral vessel continuity after subtraction of baseline signal analogous to digital subtraction angiography. Changes in collateral quality, Tmax hypoperfusion severity, and infarct growth were assessed between baseline and days 3 to 5 perfusion-diffusion MRI. Acute MRI was analysed for 88 patients imaged 3 to 6 hours after ischemic stroke onset. Better collateral flow at baseline was associated with larger perfusion-diffusion mismatch (Spearman's Rho 0.51, P<0.001) and smaller baseline diffusion lesion volume (Rho -0.70, P<0.001). In 30 patients without reperfusion at day 3 to 5, deterioration in collateral quality between baseline and subacute imaging was strongly associated with absolute (P=0.02) and relative (P<0.001) infarct growth. The deterioration in collateral grade correlated with increased mean Tmax hypoperfusion severity (Rho -0.68, P<0.001). Deterioration in Tmax hypoperfusion severity was also significantly associated with absolute (P=0.003) and relative (P=0.002) infarct growth. Collateral flow is dynamic and failure is associated with infarct growth. PMID:23652626

  5. Pulsatile magneto-hydrodynamic blood flows through porous blood vessels using a third grade non-Newtonian fluids model.

    Science.gov (United States)

    Akbarzadeh, Pooria

    2016-04-01

    In this paper, the unsteady pulsatile magneto-hydrodynamic blood flows through porous arteries concerning the influence of externally imposed periodic body acceleration and a periodic pressure gradient are numerically simulated. Blood is taken into account as the third-grade non-Newtonian fluid. Besides the numerical solution, for small Womersley parameter (such as blood flow through arterioles and capillaries), the analytical perturbation method is used to solve the nonlinear governing equations. Consequently, analytical expressions for the velocity profile, wall shear stress, and blood flow rate are obtained. Excellent agreement between the analytical and numerical predictions is evident. Also, the effects of body acceleration, magnetic field, third-grade non-Newtonian parameter, pressure gradient, and porosity on the flow behaviors are examined. Some important conclusions are that, when the Womersley parameter is low, viscous forces tend to dominate the flow, velocity profiles are parabolic in shape, and the center-line velocity oscillates in phase with the driving pressure gradient. In addition, by increasing the pressure gradient, the mean value of the velocity profile increases and the amplitude of the velocity remains constant. Also, when non-Newtonian effect increases, the amplitude of the velocity profile. PMID:26792174

  6. Biophysical Properties of Scaffolds Modulate Human Blood Vessel Formation from Circulating Endothelial Colony-Forming Cells

    Science.gov (United States)

    Critser, Paul J.; Yoder, Mervin C.

    A functional vascular system forms early in development and is continually remodeled throughout the life of the organism. Impairment to the regeneration or repair of this system leads to tissue ischemia, dysfunction, and disease. The process of vascular formation and remodeling is complex, relying on local microenvironmental cues, cytokine signaling, and multiple cell types to function properly. Tissue engineering strategies have attempted to exploit these mechanisms to develop functional vascular networks for the generation of artificial tissues and therapeutic strategies to restore tissue homeostasis. The success of these strategies requires the isolation of appropriate progenitor cell sources which are straightforward to obtain, display high proliferative potential, and demonstrate an ability to form functional vessels. Several populations are of interest including endothelial colony-forming cells, a subpopulation of endothelial progenitor cells. Additionally, the development of scaffolds to deliver and support progenitor cell survival and function is crucial for the formation of functional vascular networks. The composition and biophysical properties of these scaffolds have been shown to modulate endothelial cell behavior and vessel formation. However, further investigation is needed to better understand how these mechanical properties and biophysical properties impact vessel formation. Additionally, several other cell populations are involved in neoangiogenesis and formation of tissue parenchyma and an understanding of the potential impact of these cell populations on the biophysical properties of scaffolds will also be needed to advance these strategies. This chapter examines how the biophysical properties of matrix scaffolds can influence vessel formation and remodeling and, in particular, the impact on in vivo human endothelial progenitor cell vessel formation.

  7. Evaluation of creep-fatigue crack growth for large-scale FBR reactor vessel and NDE assessment

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Young Sang; Kim, Jong Bum; Kim, Seok Hun; Yoo, Bong

    2001-03-01

    Creep fatigue crack growth contributes to the failure of FRB reactor vessels in high temperature condition. In the design stage of reactor vessel, crack growth evaluation is very important to ensure the structural safety and setup the in-service inspection strategy. In this study, creep-fatigue crack growth evaluation has been performed for the semi-elliptical surface cracks subjected to thermal loading. The thermal stress analysis of a large-scale FBR reactor vessel has been carried out for the load conditions. The distributions of axial, radial, hoop, and Von Mises stresses were obtained for the loading conditions. At the maximum point of the axial and hoop stress, the longitudinal and circumferential surface cracks (i.e. PTS crack, NDE short crack and shallow long crack) were postulated. Using the maximum and minimum values of stresses, the creep-fatigue crack growth of the proposed cracks was simulated. The crack growth rate of circumferential cracks becomes greater than that of longitudinal cracks. The total crack growth of the largest PTS crack is very small after 427 cycles. The structural integrity of a large-scale reactor can be maintained for the plant life. The crack depth growth of the shallow long crack is faster than that of the NDE short crack. In the ISI of the large-scale FBR reactor vessel, the ultrasonic inspection is beneficial to detect the shallow circumferential cracks.

  8. Evaluation of creep-fatigue crack growth for large-scale FBR reactor vessel and NDE assessment

    International Nuclear Information System (INIS)

    Creep fatigue crack growth contributes to the failure of FRB reactor vessels in high temperature condition. In the design stage of reactor vessel, crack growth evaluation is very important to ensure the structural safety and setup the in-service inspection strategy. In this study, creep-fatigue crack growth evaluation has been performed for the semi-elliptical surface cracks subjected to thermal loading. The thermal stress analysis of a large-scale FBR reactor vessel has been carried out for the load conditions. The distributions of axial, radial, hoop, and Von Mises stresses were obtained for the loading conditions. At the maximum point of the axial and hoop stress, the longitudinal and circumferential surface cracks (i.e. PTS crack, NDE short crack and shallow long crack) were postulated. Using the maximum and minimum values of stresses, the creep-fatigue crack growth of the proposed cracks was simulated. The crack growth rate of circumferential cracks becomes greater than that of longitudinal cracks. The total crack growth of the largest PTS crack is very small after 427 cycles. The structural integrity of a large-scale reactor can be maintained for the plant life. The crack depth growth of the shallow long crack is faster than that of the NDE short crack. In the ISI of the large-scale FBR reactor vessel, the ultrasonic inspection is beneficial to detect the shallow circumferential cracks

  9. At-vessel mortality and blood biochemical status of elasmobranchs caught in an Australian commercial longline fishery

    Directory of Open Access Journals (Sweden)

    Paul A. Butcher

    2015-01-01

    Full Text Available This study investigates mortality of sharks in a commercial longline fishery in Australia. To examine the rate and biological, environmental and technological factors contributing to at-vessel mortality, four setlines with 120 gangions possessing ‘hook timers’ were deployed daily (for 7h and 14h using conventional gears from two commercial fishing vessels during 2013. A total of 689 animals across 22 species and including 18 elasmobranchs were landed. For the five species (Carcharhinus spp., and one genus (Sphyrna spp where there were sufficient numbers for analysis, generalised linear mixed models showed that species and the elapsed time spent on the line after hooking were the strongest predictors of at-vessel mortality, with spinner (Carcharhinus brevipinna, blacktip (C. limbatus and hammerhead (Sphyrna spp sharks exhibiting the highest death rates. The variables which best explained mortality, included: (i sex of the caught sharks, and the interaction between species with (ii capture depth, and (iii the elapsed time spent on the line after hooking. For the subset of dusky (C. obscurus and sandbar (C. plumbeus sharks examined for physiological status at the point of capture, very few of the 13 chosen blood analytes varied significantly. Given the observed high mortality rates and stress associated with the time spent on the line after capture, operational changes to reduce these adverse impacts should be considered. Even simple changes such as shorter soak times could considerably mitigate these impacts.

  10. Treatment of radiation exposure and regeneration medicine. Regeneration treatment of blood vessels by transplantation of autologous marrow monocytes

    International Nuclear Information System (INIS)

    Described are usefulness and future view of regenerative medicine in the treatment of radiation exposure as exemplified by the vascular regeneration by autologous marrow cell transplantation. Vascular endothelial cells (VEC), possessing a high ability to divide, are known sensitive to radiation, which gives damage of blood vessel to alter its permeability leading to apoptosis of VEC, organ/tissue injuries and final damages in the cerebral blood vessels, central nervous system and skin, the acute radiation syndrome (ARS). Authors present successful cases of patients with chronic limb ischemia in the Therapeutic Angiogenesis using Cell Transplantation Trial (TACT), to whom the treatment is conducted with transplantation of autologous marrow monocyte fraction containing endothelial progenitor cells that differentiate to VEC. As well, they touch on a case of the patient encountered in a nuclear accident, mentioning that VEC are found partly derived from the donor after heamatopoietic stem cell transplantation (HSCT). Efficacy of HSCT in a literature is reviewed and commented to be an only limited one in 31 patients of various radiation accidents. However, treatment of ARS where stem cells are target, with regenerative medicine will become more useful in future, as basic and clinical researches will provide requisite findings. (T.I.)

  11. Erythropoietin-enhanced endothelial progenitor cell recruitment in peripheral blood and renal vessels during experimental acute kidney injury in rats.

    Science.gov (United States)

    Cakiroglu, Figen; Enders-Comberg, Sora Maria; Pagel, Horst; Rohwedel, Jürgen; Lehnert, Hendrik; Kramer, Jan

    2016-03-01

    Beneficial effects of erythropoietin (EPO) have been reported in acute kidney injury (AKI) when administered prior to induction of AKI. We studied the effects of EPO administration on renal function shortly after ischemic AKI. For this purpose, rats were subjected to renal ischemia for 30 min and EPO was administered at a concentration of 500 U/kg either i.v. as a single shot directly after ischemia or with an additional i.p. dose until 3 days after surgery. The results were compared with AKI rats without EPO application and a sham-operated group. Renal function was assessed by measurement of serum biochemical markers, histological grading, and using an isolated perfused kidney (IPK) model. Furthermore, we performed flow cytometry to analyze the concentration of endothelial progenitor cells (EPCs) in the peripheral blood and renal vessels. Following EPO application, there was only a statistically non-significant tendency of serum creatinine and urea to improve, particularly after daily EPO application. Renal vascular resistance and the renal perfusion rate were not significantly altered. In the histological analysis, acute tubular necrosis was only marginally ameliorated following EPO administration. In summary, we could not demonstrate a significant improvement in renal function when EPO was applied after AKI. Interestingly, however, EPO treatment resulted in a highly significant increase in CD133- and CD34-positive EPC both in the peripheral blood and renal vessels. PMID:26616141

  12. Tenascin-W is a specific marker of glioma-associated blood vessels and stimulates angiogenesis in vitro

    Science.gov (United States)

    Martina, Enrico; Degen, Martin; Rüegg, Curzio; Merlo, Adrian; Lino, Maddalena M.; Chiquet-Ehrismann, Ruth; Brellier, Florence

    2010-01-01

    The microenvironment hosting a tumor actively participates in regulating tumor cell proliferation, migration, and invasion. Among the extracellular matrix proteins enriched in the stroma of carcinomas are the tenascin family members tenascin-C and tenascin-W. Whereas tenascin-C overexpression in gliomas is known to correlate with poor prognosis, the status of tenascin-W in brain tumors has not been investigated so far. In the present study, we analyzed protein levels of tenascin-W in 38 human gliomas and found expression of tenascin-W in 80% of the tumor samples, whereas no tenascin-W could be detected in control, nontumoral brain tissues. Double immunohistochemical staining of tenascin-W and von Willebrand factor revealed that tenascin-W is localized around blood vessels, exclusively in tumor samples. In vitro, the presence of tenascin-W increased the proportion of elongated human umbilical vein endothelial cells (HUVECs) and augmented the mean speed of cell migration. Furthermore, tenascin-W triggered sprouting of HUVEC spheroids to a similar extent as the proangiogenic factor tenascin-C. In conclusion, our study identifies tenascin-W as a candidate biomarker for brain tumor angiogenesis that could be used as a molecular target for therapy irrespective of the glioma subtype.—Martina, E., Degen, M., Rüegg, C., Merlo, A., Lino, M. M., Chiquet-Ehrismann, R., Brellier, F. Tenascin-W is a specific marker of glioma-associated blood vessels and stimulates angiogenesis in vitro. PMID:19884327

  13. Effect of gravitation stress and hypokinesia on blood vessels of the testicle

    Science.gov (United States)

    Palazhchenko, E. F.

    1979-01-01

    Rabbits were exposed to single maximum endurable stresses of cranio-caudal direction, hypokinesia for periods of one to eight weeks, and hypokinesia followed by gravitation stresses. The stresses caused dilatation of vessels, greater sinuosity, and occasional ruptures of the walls and extravasation. The greater part of the capillaries were dilated; the greatest part constricted. In hypokinesia there was an increasing atrophy of the testes. Significant results are reported.

  14. Automated detection of kinks from blood vessels for optic cup segmentation in retinal images

    Science.gov (United States)

    Wong, D. W. K.; Liu, J.; Lim, J. H.; Li, H.; Wong, T. Y.

    2009-02-01

    The accurate localization of the optic cup in retinal images is important to assess the cup to disc ratio (CDR) for glaucoma screening and management. Glaucoma is physiologically assessed by the increased excavation of the optic cup within the optic nerve head, also known as the optic disc. The CDR is thus an important indicator of risk and severity of glaucoma. In this paper, we propose a method of determining the cup boundary using non-stereographic retinal images by the automatic detection of a morphological feature within the optic disc known as kinks. Kinks are defined as the bendings of small vessels as they traverse from the disc to the cup, providing physiological validation for the cup boundary. To detect kinks, localized patches are first generated from a preliminary cup boundary obtained via level set. Features obtained using edge detection and wavelet transform are combined using a statistical approach rule to identify likely vessel edges. The kinks are then obtained automatically by analyzing the detected vessel edges for angular changes, and these kinks are subsequently used to obtain the cup boundary. A set of retinal images from the Singapore Eye Research Institute was obtained to assess the performance of the method, with each image being clinically graded for the CDR. From experiments, when kinks were used, the error on the CDR was reduced to less than 0.1 CDR units relative to the clinical CDR, which is within the intra-observer variability of 0.2 CDR units.

  15. Effect of silver nanoparticles and hydroxyproline, administered in ovo, on the development of blood vessels and cartilage collagen structure in chicken embryos.

    Science.gov (United States)

    Beck, Iwona; Hotowy, Anna; Sawosz, Ewa; Grodzik, Marta; Wierzbicki, Mateusz; Kutwin, Marta; Jaworski, Sławomir; Chwalibog, André

    2015-01-01

    It has been considered that concentrations of certain amino acids in the egg are not sufficient to fully support embryonic development of modern broilers. In this study we evaluated embryo growth and development with particular emphasis on one of the major components of connective tissue, collagen. Experiments were performed on Ross 308 chicken embryos from 160 fertilised eggs. Experimental solutions of silver nanoparticles (Ag), hydroxyproline solution (Hyp) and a complex of silver nanoparticles with hydroxyproline (AgHyp) were injected into albumen, and embryos were incubated until day 20. An assessment of the mass of embryo and selected organs was carried out followed by measurements of the expression of the key signalling factors' fibroblast growth factor-2 (FGF-2) and vascular endothelial growth factor-A (VEGF-A). Finally, an evaluation of collagen microstructure using scanning electron microscopy was performed. Our results clearly indicate that Hyp, Ag and AgHyp administered in ovo to chicken embryos did not harm embryos. Comparing to the control group, Hyp, Ag and the AgHyp complex significantly upregulated expression of the FGF-2 at the mRNA and protein levels. Moreover, Hyp, Ag and, in particular, the complex of AgHyp significantly increased blood vessel size, cartilage collagen fibre lattice size and bundle thickness. The general conclusion from this study is that AgHyp treatment may help to build a stronger and longer lasting form of collagen fibres. PMID:25530495

  16. Synthetic reconstruction of dynamic blood flow in cortical arteries using optical coherence tomography for the evaluation of vessel compliance

    Science.gov (United States)

    Baraghis, Edward; Bolduc, Virginie; Gillis, Marc-Antoine; Srinivasan, Vivek J.; Thorin, Éric; Boudoux, Caroline; Lesage, Frédéric

    2011-03-01

    Optical Coherence Tomography (OCT) has recently been used to produce 3D angiography of microvasculature in the rodent brain in-vivo and blood flow maps of large vessels. Key enabling developments were novel algorithms for detecting Doppler shifts produced by moving scatterers and new scanning protocols tailored to increase sensitivity to small flow speeds. These progresses were pushed by the need for a non invasive imaging modality to monitor quantitative blood flow at a higher resolution and a greater depth than could be achieved by other means. The rationale for this work originates from new hypotheses regarding the role of blood regulation in neurodegenerative diseases and from current investigations of animal models of vascular degeneration. In this work we demonstrate the synthetic reconstruction of dynamic blood flow in mice over the course of a single cardiac cycle in an 800μm wide by ~ 3mm deep B-Frame slice with a lateral resolution of 10μm and a depth resolution of 7μm. Images were taken using a cranial window over the exposed parietal bone of mice skull. Electrocardiography (ECG) recordings were co registered with the OCT A lines at high temporal resolution. QRS peak detection was then used to locate the time value of each A-line in the cardiac cycle and to reconstruct a synthetic temporal frame over one cardiac cycle. Doppler speed in this cardiac cycle was used to measure temporal variations of flow inside arteries and of their area. Three dimensional volume scans yielded measurements of quantitative blood flow on the same arteries. Using these informations a measure of compliance could be established. Comparing measures between atherosclerotic (ATX) and wild type (WT) mice revealed higher blood flow in WT mice, suggested lower systemic compliance in the ATX group but higher compliance of cerebral vasculature on these mice. These results are consistent with expectations showing that OCT is a potential tool for in-vivo arterial compliance evaluation.

  17. Stable crack growth during over stressing or proof testing of pressure vessels

    International Nuclear Information System (INIS)

    In an earlier study several years ago an attempt has been made by a study group in Switzerland formed by representatives of utilities, manufacturers, inspection agency and the licensing authority to evaluate systematically the advantages and disadvantages of a proof test for a reactor pressure vessel (RPV) taking into account the different aspects involved. In this study, the present day practice in the requirements regarding proof testing in several countries with nuclear power plants were assessed. Using the method of fracture mechanics, taking into account the proof test conditions and material behaviour at hand, qualified quantitative statements were then sought for. One of the important findings of the study was that a sufficiently accurate determination of stable crack growth (SCG) during proof testing is a necessary precondition for a qualified quantitative statement. At that time this requirement could not be met. The aim of the present exercise of collecting available information on SCG was twofold: to get an overview of the present day requirements on pre-service and in-service proof testing of reactor pressure vessels in different countries with NPPs; to collect data on stable crack growth due to over stressing during proof tests to be used in the quantitative assessment, using fracture mechanics methods, and the potential benefit, if any, of proof tests. In the framework of the present study, the originally stipulated aims could not be achieved. It turned out to be a very complex and difficult problem, where various important aspects are little known and could not be assessed without further comprehensive theoretical and experimental investigations

  18. C - reactive protein and chitinase 3-like protein 1 as biomarkers of spatial redistribution of retinal blood vessels on digital retinal photography in patients with diabetic retinopathy

    Directory of Open Access Journals (Sweden)

    Sonja Predrag Cekic

    2014-08-01

    Full Text Available The aim of the study was to investegate the correlation between the levels of CRP and YKL-40 in blood samples with morphometric parameters of retinal blood vessels in patients with diabetic retinopathy.Blood laboratory examination of 90 patients included the measurement of glycemia, HbA1C, total cholesterol, LDL-C, HDL-C, triglycerides and CRP. Levels of YKL-40 were detected and measured in serum by ELISA (Micro VueYKL-40 EIA Kit, Quidel Corporation, San Diego, USA.Morphmetric analysis was performed with ImageJ software (http://rsbweb.nih.gov/ij/ for digital retinal photography. We measured the number, diameter of retinal blood vessels in five different parts concentric to the optic disc. Differences between the morphometric parameters and the blood test analysis results were evaluated using the Student’s t – test. One Way ANOVA was used to establish the significance of differences.CRP and YKL-40 levels were moderately higher in the group of patients with severe diabetic retinopathy. Levels of YKL-40 correlated positively with diameter and negatively with number of retinal blood vessels. The average number of the blood vessels per retinal zone was significantly higher in the group of patients with mild non-proliferative diabetic retinopathy than in the group with severe form in the optic disc and all five retinal zones. The average outer diameter of the evaluated retinal zones and optic disc vessels was significantly higher in the group with severe compared to the group with mild diabetic retinopathy.Morphological analysis of the retinal vessels on digital fundus photography and correlation with YKL-40 may be valuable for the follow-up of diabetic retinopathy.

  19. Two-phase non-linear model for the flow through stenosed blood vessels

    International Nuclear Information System (INIS)

    Pulsatile flow of a two-phase model for blood flow through arterial stenosis is analyzed through a mathematical analysis. The effects of pulsatility, stenosis, peripheral layer and non-Newtonian behavior of blood, assuming the blood in the core region as a Herschel-Bulkley fluid and the plasma in the peripheral layer as a Newtonian fluid, are discussed. A perturbation method is used to solve the resulting system of non-linear quasi-steady differential equations. The expressions for velocity, wall shear stress, plug core radius, flow rate and resistance to flow are obtained. It is noticed that the plug core radius and resistance to flow increase as the stenosis size increases while all other parameters held constant The wall shear stress increases with the increase of yield stress while keeping other parameters as invariable. It is observed that the velocity increases with the axial distance in the stenosed region of the tube upto the maximum projection of the stenosis

  20. Nanostructural haemocompatible coatings for the internal side of artificial blood vessels

    Science.gov (United States)

    Trembecka-Wojciga, K.; Major, R.; Lackner, J. M.; Butruk-Raszeja, B.; Sanak, M.; Major, B.

    2016-03-01

    The main goal of the work was to elaborate low thrombogenicity of surface inside tube-like elements for cardiovascular system support by combination of low-temperature glow discharge and hydrogel coatings to inhibit blood-clotting cascade activation. A large share of amorphous phase silicon was observed in the microstructure analysis. The crystalline elements were uniformly distributed in the amorphous structure. Combination of low thickness, the proper microstructure and density of the coatings provided a highly flexible nature of the whole system. The blood-material interaction was analyzed in vitro in dynamic conditions by using a designed and fabricated novel blood flow simulator. Coatings deposited by the glow discharge expressed good hemocopatibile properties. The use of hydrogel coatings did not reduce coagulation parameter. Hydrogel coatings did not improve the hemocompatibility of the surface modified with carbon based coatings. Modification of surface with hydrogel resulted in further increased risk of hemolysis.

  1. Identifying a therapeutic target for ablating new blood vessel formation in patients with asthma

    NARCIS (Netherlands)

    Ge, Qi; Burgess, Janette; Ashton, Anthony

    2015-01-01

    Introduction: Angiogenesis is a feature of chronic asthma with the levels of multiple proangiogenic factors, including connective tissue growth factor (CTGF) and vascular growth factor (VEGF), increased in the lungs of patients with asthma. Preliminary data from our lab suggests that the proangiogen

  2. Effects of simulated weightlessness on fish otolith growth: Clinostat versus Rotating-Wall Vessel

    Science.gov (United States)

    Brungs, Sonja; Hauslage, Jens; Hilbig, Reinhard; Hemmersbach, Ruth; Anken, Ralf

    2011-09-01

    Stimulus dependence is a general feature of developing sensory systems. It has been shown earlier that the growth of inner ear heavy stones (otoliths) of late-stage Cichlid fish ( Oreochromis mossambicus) and Zebrafish ( Danio rerio) is slowed down by hypergravity, whereas microgravity during space flight yields an opposite effect, i.e. larger than 1 g otoliths, in Swordtail ( Xiphophorus helleri) and in Cichlid fish late-stage embryos. These and related studies proposed that otolith growth is actively adjusted via a feedback mechanism to produce a test mass of the appropriate physical capacity. Using ground-based techniques to apply simulated weightlessness, long-term clinorotation (CR; exposure on a fast-rotating Clinostat with one axis of rotation) led to larger than 1 g otoliths in late-stage Cichlid fish. Larger than normal otoliths were also found in early-staged Zebrafish embryos after short-term Wall Vessel Rotation (WVR; also regarded as a method to simulate weightlessness). These results are basically in line with the results obtained on Swordtails from space flight. Thus, the growth of fish inner ear otoliths seems to be an appropriate parameter to assess the quality of "simulated weightlessness" provided by a particular simulation device. Since CR and WVR are in worldwide use to simulate weightlessness conditions on ground using small-sized specimens, we were prompted to directly compare the effects of CR and WVR on otolith growth using developing Cichlids as model organism. Animals were simultaneously subjected to CR and WVR from a point of time when otolith primordia had begun to calcify both within the utricle (gravity perception) and the saccule (hearing); the respective otoliths are the lapilli and the sagittae. Three such runs were subsequently carried out, using three different batches of fish. The runs were discontinued when the animals began to hatch. In the course of all three runs performed, CR led to larger than normal lapilli, whereas WVR

  3. [Function of dopamine in mesenteric blood vessels of rats poisoned with lead and cadmium].

    Science.gov (United States)

    Skoczyńska, A; Wróbel, J; Turczyn, B

    2000-01-01

    The aim of this study was to evaluate the impact of combined exposure to lead and cadmium, used in hypertensive doses, on the reactivity of isolated mesenteric rat vessels to dopamine. Experiments were performed on 64 male Buffalo rats (195-245 g body weight) administered intragastrically with lead acetate (35 mg Pb/kg b.w.) and/or cadmium chloride (5 mg Cd/kg b.w.) once a week for seven weeks. The isolated mesenteric bed was prepared according to McGregor's method. Dopamine (800 micrograms) was injected before and during the infusion, one after the other, of angiotensin converting enzyme (0.0004 j/ml/min), ketoprofen (0.2 mg/ml/min), and losartan (0.05 mg/ml/min) or infusion of nitric oxide synthase blocker, N-omega-nitro-L-argine (22 micrograms/ml/min), verapamil (0.001 mg/ml/min), and then propranolol (0.3 mg/ml/min). The results show an unchanged, in comparison to controls, vascular effect of dopamine in lead and cadmium poisoned rats. However, these metals modified the reactivity of mesenteric vessels to endogenous angiotensin and prostaglandins mediated pressor action of dopamine. PMID:11199173

  4. Computer Simulations of Pulsatile Human Blood Flow Through 3D-Models of the Human Aortic Arch, Vessels of Simple Geometry and a Bifurcated Artery: Investigation of Blood Viscosity and Turbulent Effects

    CERN Document Server

    Sultanov, Renat A

    2008-01-01

    We report computational results of blood flow through a model of the human aortic arch and a vessel of actual diameter and length. On the top of the aortic arch the branching of the %%three arteries are included: the subclavian and jugular. A realistic pulsatile flow is used in all simulations. Calculations for bifurcation type vessels are also carried out and presented. Different mathematical methods for numerical solution of the fluid dynamics equations have been considered. The non-Newtonian behaviour of the human blood is investigated together with turbulence effects. A detailed time-dependent mathematical convergence test has been carried out. The results of computer simulations of the blood flow in vessels of three different geometries are presented: for pressure, strain rate and velocity component distributions we found significant disagreements between our results obtained with realistic non-Newtonian treatment of human blood and the widely used method in the literature: a simple Newtonian approximati...

  5. Expression of transforming growth factor beta 1-related signaling proteins in irradiated vessels

    Energy Technology Data Exchange (ETDEWEB)

    Preidl, Raimund H.M.; Moebius, Patrick; Weber, Manuel; Neukam, Friedrich W.; Schlegel, Andreas; Wehrhan, Falk [University of Erlangen- Nuernberg, Department of Oral and Maxillofacial Surgery, Erlangen (Germany); University of Erlangen- Nuernberg, Erlangen (Germany); Amann, Kerstin [University of Erlangen- Nuernberg, Erlangen (Germany)

    2014-12-09

    Microvascular free tissue transfer is a standard method in head and neck reconstructive surgery. However, previous radiotherapy of the operative region is associated with an increased incidence in postoperative flap-related complications and complete flap loss. As transforming growth factor beta (TGF-β) 1 and galectin-3 are well known markers in the context of fibrosis and lectin-like oxidized low-density lipoprotein 1 (LOX-1) supports vascular atherosclerosis, the aim of this study was to evaluate the expression of TGF-β1 and related markers as well as LOX-1 in irradiated vessels. To evaluate the expression of galectin-3, Smad 2/3, TGF-β1, and LOX-1, 20 irradiated and 20 nonirradiated arterial vessels were used for immunohistochemical staining. We semiquantitatively assessed the ratio of stained cells/total number of cells (labeling index). Expression of galectin-3, Smad 2/3, and TGF-β1 was significantly increased in previously irradiated vessels compared with nonirradiated controls. Furthermore, LOX-1 was expressed significantly higher in irradiated compared with nonirradiated vessels. Fibrosis-related proteins like galectin-3, Smad 2/3, and TGF-β1 are upregulated after radiotherapy and support histopathological changes leading to vasculopathy of the irradiated vessels. Furthermore, postoperative complications in irradiated patients can be explained by increased endothelial dysfunction caused by LOX-1 in previously irradiated patients. Consequently, not only TGF-β1 but also galectin-3inhibitors may decrease complications after microsurgical tissue transfer. (orig.) [German] Der freie mikrovaskulaere Gewebetransfer gilt heute als fester Standard in der rekonstruktiven Kopf-Hals-Chirurgie. Es zeigte sich jedoch, dass im Falle einer stattgehabten Bestrahlung im Operationsgebiet mit einer erhoehten Rate an transplantatbezogenen Komplikationen gerechnet werden muss. Sowohl TGF-β1 als auch Galektin-3 sind bekannte Mediatoren in Bezug auf die Fibroseentstehung

  6. Assessing blood vessel abnormality via extracting scattering coefficients from OCT images

    Science.gov (United States)

    Levitz, David; Andersen, Claus B.; Frosz, Michael H.; Thrane, Lars; Hansen, Peter R.; Jorgensen, Thomas M.; Andersen, Peter E.

    2003-10-01

    Background: Coronary artery disease (CAD) is the leading cause of mortality and morbidity in the industrialized world. Optical coherence tomography (OCT) is a high-resolution intravascular imaging technology with a potential for in vivo plaque characterization. Although structural remodeling of the arterial vessel wall during plaque development can change tissue optical scattering properties, very limited evidence is available on the exact optical scattering properties of plaques. The scattering coefficient, μs, and the anisotropy factor, g, can be derived from OCT images by fitting a theoretical model to individual depth-scans. The aim of the current study was to use this method to examine by OCT the scattering properties of human arteries with different stages of atherosclerotic lesion development. Methods: Normal (n=4), lipid-rich (n=4), and fibrous (n=3) aortic blocks as classified by parallel histopathologic examination were obtained within 24 hours of death and imaged by OCT. The intima was located in the OCT images, and then further split into 115 blocks (41 normal, 40 lipid-rich, and 34 fibrous) of adjacent OCT depth-scans transversely spanning ~200-300 μm. Scattering signals from each block were averaged and fit to the theoretical model. From these fittings, μs and g were extracted. Results and Discussion: The optical scattering properties of normal aortic intima were quite different from lipid-rich and fibrous lesions, respectively. We discovered that the normal intima was generally highly forward scattering, i.e., with 0.917diseased vessels were much less so. Furthermore, normal vessels usually had 15collagen, lipids, and elastin. Based on our findings, we defined a criteria of μs and g for normal intimas, using the above values of μs and g as cutoffs. Our "normal" criteria demonstrated high sensitivity (92.4%) and specificity (82.4%). We conclude, that a detailed analysis of the tissue optical scattering properties can enhance the capacity of OCT

  7. Temporal patterns of blood flow and nitric oxide synthase expression affect macrophage accumulation and proliferation during collateral growth

    Directory of Open Access Journals (Sweden)

    Sager Hendrik B

    2010-09-01

    Full Text Available Abstract Background The involvement of collateral blood flow/fluid shear stress, nitric oxide (NO, and macrophages during collateral growth (arteriogenesis is established, but their interplay remains paradoxical. Methods In order to further elucidate the "fluid shear stress/NO/macrophage" paradox, we investigated the time course of collateral blood flow (using a Doppler flow probe and NOS expression (immunohistochemistry, Western blot in growing rat collateral vessels after femoral artery occlusion and their impact on macrophage recruitment and collateral proliferation (immunohistochemistry, angiographies. Results (values are given as mean ± standard error of mean Early after occlusion, collateral blood flow was significantly reduced (pre- 90.0 ± 4.5 vs. post-occlusion 62.5 ± 5.9 μl/min; p p p p Conclusions We propose the following resolution of the "fluid shear stress/NO/macrophage" paradox: Collateral blood flow and NOS expression are initially reduced during arteriogenesis allowing macrophages to accumulate and therewith enhancing collateral proliferation. After homing of macrophages (24 h after occlusion, collateral blood flow and NOS expression recover in order to join the effects of macrophages for restoring blood flow.

  8. Strategies for informative displays of blood vessels using magnetic resonance imaging data

    International Nuclear Information System (INIS)

    Algorithms which aid three-dimensional visualization of particular structures have been developed for MRI. This involves identifying regions of interest, placing them in a three-dimensional context, and displaying projections onto a two-dimensional monitor. The images can be displayed from various perspectives, contrast-enhanced, or encoded by color or grey scale to show relationships other than signal intensity to differentiate tissues. In order to be useful, the new images must provide more information or facilitate some other even more tedious procedure. The MRI vessel reconstructions, in addition to the improved anatomic visualization, display information about flow and patent area which is difficult to determine by looking at the original slices. (Auth.)

  9. PET/CT imaging of atherosclerotic blood vessel alterations; Bildgebung atherosklerotischer Gefaesswandveraenderungen mit der PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Rominger, A.; Bartenstein, P.; Hacker, M. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Klinik und Poliklinik fuer Nuklearmedizin, Muenchen (Germany); Rist, C.; Nikolaou, K.; Reiser, M.F.; Saam, T. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany)

    2010-04-15

    Atherosclerosis is a chronic inflammatory disease of middle sized and large vessels with sequelae comprising the most frequent causes of death in the Western world. Modern imaging modalities are being introduced for the study of atherosclerosis with emphasis on the detection of vulnerable plaques. The hybrid imaging method PET/CT presents advantages for the localization of vulnerable plaques based on the uptake of various molecular imaging agents indicative of inflammatory processes. Using semiquantitative image analysis fluorodeoxyglucose (FDG) uptake in large peripheral vessels has been identified in a series of 21 patients, who were scanned first with the previous generation of PET/CT scanner and subsequently with a new generation apparatus, after a mean interval of 6.5 months. The mean ratio of FDG uptake in the walls of eight large vessels to the blood-pool activity (TBR) was nearly identical in the two PET/CT sessions (TBR{sub 1} 1.26 versus TBR{sub 2} 1.28; p=n.s.), indicating independence of the TBR endpoint from the particular instrumentation. (orig.) [German] Die Atherosklerose ist eine chronische, entzuendliche Erkrankung der mittleren und grossen Gefaesse, deren Folgen die haeufigste Todesursache in der westlichen Welt darstellen. In diesem Beitrag werden die Moeglichkeiten moderner Bildgebungsmodalitaeten vorgestellt, die zur Identifikation entzuendlicher, so genannter vulnerabler Plaques unterschiedlich gut geeignet sind. Der Schwerpunkt liegt auf der Hybridbildgebungsmethode PET/CT mit einer Uebersicht bisheriger Studien und moeglicherweise geeigneter neuer Ansaetze molekularer Bildgebungsmodalitaeten. Es erfolgt eine Darstellung der semiquantitativen Bildanalyse, die durch einen Vergleich von 21 Patienten, die an 2 unterschiedlichen PET/CT-Scannern ueber einen mittleren Zeitraum von 6,5 Monaten untersucht wurden, untermauert wird. Hier zeigte sich, dass ein Quotient aus der FDG-Aufnahme in der Gefaesswand und der Blutpoolaktivitaet unabhaengig vom

  10. BLOOD VESSELS SEGMENTATION BY RADIAL GRADIENT SYMMETRY METHOD VIA DIFFERENT THRESHOLD VALUES

    Directory of Open Access Journals (Sweden)

    Kumar Parasuraman

    2015-02-01

    Full Text Available A Key identifier for some diseases such as arteriosclerosis, hypertension, macular edema, diabetes mellitus, and the recognition qualities of geometrical changes in retinal veins and supply routes are recognized by Retinal Vein morphology and might be connected to a mixed carrier of clinical studies. Extraction of the retinal veins is a help to see all the more about its morphology and will give a superior wellspring of data for contemplating the different related diseases. Two of the significant issues in the extraction of retinal veins are the vicinity of a wide assortment of vessel widths and inhomogeneous foundation of the retina. Machine based dissection for computerized extraction of veins in retinal images will help eye mind pro's screen bigger populaces for vessel variations from the norm. In this extend a technique for robotized extraction of fundus pictures of the retinal vein is introduced. This paper displays another strategy for vein recognition in computerized retinal pictures. In this system first separating is carried out utilizing reciprocal channel to uproot the commotions in the picture and second, differentiates the fundus picture into red, green and blue channels. Third, Kirsch's format with spatial separating is utilized to discover the beginning and bearing of the veins and for smoothing the limits. Fourth, the veins are fragmented by applying threshold values and by utilizing outspread radial symmetry strategy. These segmentations are looked at against manual estimations and between imaging strategies. Its adequacy and strength with distinctive picture conditions, together with its smoothness and quick usage, make this vein division proposal suitable for retinal picture workstation examination, for example, computerized screening for right on time diabetic retinopathy discovery.

  11. New approach to carbon monoxide poisoning treatment by laser-induced photodissociation of carboxyhemoglobin of cutaneous blood vessels

    Science.gov (United States)

    Asimov, Mustafo M.; Asimov, Rustam M.; Gisbrecht, Alexander

    2005-04-01

    A new approach to carbon monoxide poisoning treatment based on laser-induced photodissociation of the carboxyhemoglobin is proposed. Using the simple model of laser tissue interaction the action spectra of laser radiation on carboxyhemoglobin of cutaneous blood vessels has been calculated. The results of the calculatoins indicate that there is a relatively narrow spectral range in the visible region where one could effectively irradiate carboxyhemoglobin through the tissue not in a deep distances. In the case of deeper penetration, the action spectra of laser radiation shifts toward the longer wavelength region. Despite the similarity of the carboxyhemoglobin and oxyhemoglobin action spectra, the significant difference in quantum yields of photodissociation makes possible to develop an effective method of carbon monoxide poisoning treatment.

  12. Combination probe for optically assisted ultrasonic velocity-change imaging aimed at detecting unstable blood vessel plaque

    Science.gov (United States)

    Tanigawa, Shohei; Mano, Kazune; Wada, Kenji; Matsunaka, Toshiyuki; Horinaka, Hiromichi

    2016-04-01

    Blood vessel plaque with a large lipid core is at risk of becoming thrombus and is likely to induce acute heart disease. To prevent this, it is necessary to determine not only the plaque's size but also its chemical composition. We, therefore, made the prototype of a combination probe to diagnose carotid artery plaque. It is used to differentiate propagation characteristics between light spectra and ultrasonic images. By propagating light and ultrasound along a common direction, it is possible to effectively warm the diagnosis domain. Moreover, the probe is thought to be compact and be easy to use for diagnosing human carotid artery plaque. We applied the combination probe to a carotid artery phantom with a lipid area and obtained an image of the ultrasonic velocity change in the fatty area.

  13. CLASSICAL AREAS OF PHENOMENOLOGY: Lattice Boltzmann simulation of behaviour of particles moving in blood vessels under the rolling massage

    Science.gov (United States)

    Yi, Hou-Hui; Yang, Xiao-Feng; Wang, Cai-Feng; Li, Hua-Bing

    2009-07-01

    The rolling massage is one of the most important manipulations in Chinese massage, which is expected to eliminate many diseases. Here, the effect of the rolling massage on a pair of particles moving in blood vessels under rolling massage manipulation is studied by the lattice Boltzmann simulation. The simulated results show that the motion of each particle is considerably modified by the rolling massage, and it depends on the relative rolling velocity, the rolling depth, and the distance between particle position and rolling position. Both particles' translational average velocities increase almost linearly as the rolling velocity increases, and obey the same law. The increment of the average relative angular velocity for the leading particle is smaller than that of the trailing one. The result is helpful for understanding the mechanism of the massage and to further develop the rolling techniques.

  14. Blood-Vessel Mimicking Structures by Stereolithographic Fabrication of Small Porous Tubes Using Cytocompatible Polyacrylate Elastomers, Biofunctionalization and Endothelialization

    Directory of Open Access Journals (Sweden)

    Birgit Huber

    2016-04-01

    Full Text Available Blood vessel reconstruction is still an elusive goal for the development of in vitro models as well as artificial vascular grafts. In this study, we used a novel photo-curable cytocompatible polyacrylate material (PA for freeform generation of synthetic vessels. We applied stereolithography for the fabrication of arbitrary 3D tubular structures with total dimensions in the centimeter range, 300 µm wall thickness, inner diameters of 1 to 2 mm and defined pores with a constant diameter of approximately 100 µm or 200 µm. We established a rinsing protocol to remove remaining cytotoxic substances from the photo-cured PA and applied thio-modified heparin and RGDC-peptides to functionalize the PA surface for enhanced endothelial cell adhesion. A rotating seeding procedure was introduced to ensure homogenous endothelial monolayer formation at the inner luminal tube wall. We showed that endothelial cells stayed viable and adherent and aligned along the medium flow under fluid-flow conditions comparable to native capillaries. The combined technology approach comprising of freeform additive manufacturing (AM, biomimetic design, cytocompatible materials which are applicable to AM, and biofunctionalization of AM constructs has been introduced as BioRap® technology by the authors.

  15. Blood-Vessel Mimicking Structures by Stereolithographic Fabrication of Small Porous Tubes Using Cytocompatible Polyacrylate Elastomers, Biofunctionalization and Endothelialization.

    Science.gov (United States)

    Huber, Birgit; Engelhardt, Sascha; Meyer, Wolfdietrich; Krüger, Hartmut; Wenz, Annika; Schönhaar, Veronika; Tovar, Günter E M; Kluger, Petra J; Borchers, Kirsten

    2016-01-01

    Blood vessel reconstruction is still an elusive goal for the development of in vitro models as well as artificial vascular grafts. In this study, we used a novel photo-curable cytocompatible polyacrylate material (PA) for freeform generation of synthetic vessels. We applied stereolithography for the fabrication of arbitrary 3D tubular structures with total dimensions in the centimeter range, 300 µm wall thickness, inner diameters of 1 to 2 mm and defined pores with a constant diameter of approximately 100 µm or 200 µm. We established a rinsing protocol to remove remaining cytotoxic substances from the photo-cured PA and applied thio-modified heparin and RGDC-peptides to functionalize the PA surface for enhanced endothelial cell adhesion. A rotating seeding procedure was introduced to ensure homogenous endothelial monolayer formation at the inner luminal tube wall. We showed that endothelial cells stayed viable and adherent and aligned along the medium flow under fluid-flow conditions comparable to native capillaries. The combined technology approach comprising of freeform additive manufacturing (AM), biomimetic design, cytocompatible materials which are applicable to AM, and biofunctionalization of AM constructs has been introduced as BioRap(®) technology by the authors. PMID:27104576

  16. Vessel Segmentation and Blood Flow Simulation Using Level-Sets and Embedded Boundary Methods

    Energy Technology Data Exchange (ETDEWEB)

    Deschamps, T; Schwartz, P; Trebotich, D; Colella, P; Saloner, D; Malladi, R

    2004-12-09

    In this article we address the problem of blood flow simulation in realistic vascular objects. The anatomical surfaces are extracted by means of Level-Sets methods that accurately model the complex and varying surfaces of pathological objects such as aneurysms and stenoses. The surfaces obtained are defined at the sub-pixel level where they intersect the Cartesian grid of the image domain. It is therefore straightforward to construct embedded boundary representations of these objects on the same grid, for which recent work has enabled discretization of the Navier-Stokes equations for incompressible fluids. While most classical techniques require construction of a structured mesh that approximates the surface in order to extrapolate a 3D finite-element gridding of the whole volume, our method directly simulates the blood-flow inside the extracted surface without losing any complicated details and without building additional grids.

  17. MAPK and pro-inflammatory mediators in the walls of brain blood vessels following cerebral ischemia

    OpenAIRE

    Maddahi, Aida

    2012-01-01

    INTRODUCTION Stroke is a serious neurological disease which may lead to death and severe disability [1, 2]. There are two major types of stroke: ischemic and hemorrhagic stroke. Both are associated with disruption of blood flow to a part of the brain with rapid depletion of cellular energy and oxygen, resulting in ionic disturbances and eventually neuronal cell death [3]. The pathologic process that develops after stroke is divided into acute (within hours), sub-acute (hours to days), ...

  18. Careful treatment planning enables safe ablation of liver tumors adjacent to major blood vessels by percutaneous irreversible electroporation (IRE)

    International Nuclear Information System (INIS)

    Irreversible electroporation (IRE) is a tissue ablation method, which relies on the phenomenon of electroporation. When cells are exposed to a sufficiently electric field, the plasma membrane is disrupted and cells undergo an apoptotic or necrotic cell death. Although heating effects are known IRE is considered as non-thermal ablation technique and is currently applied to treat tumors in locations where thermal ablation techniques are contraindicated. The manufacturer of the only commercially available pulse generator for IRE recommends a voltage-to-distance ratio of 1500 to 1700 V/cm for treating tumors in the liver. However, major blood vessels can influence the electric field distribution. We present a method for treatment planning of IRE which takes the influence of blood vessels on the electric field into account; this is illustrated on a treatment of 48-year-old patient with a metastasis near the remaining hepatic vein after a right side hemi-hepatectomy. Output of the numerical treatment planning method shows that a 19.9 cm3 irreversible electroporation lesion was generated and the whole tumor was covered with at least 900 V/cm. This compares well with the volume of the hypodense lesion seen in contrast enhanced CT images taken after the IRE treatment. A significant temperature raise occurs near the electrodes. However, the hepatic vein remains open after the treatment without evidence of tumor recurrence after 6 months. Treatment planning using accurate computer models was recognized as important for electrochemotherapy and irreversible electroporation. An important finding of this study was, that the surface of the electrodes heat up significantly. Therefore the clinical user should generally avoid placing the electrodes less than 4 mm away from risk structures when following recommendations of the manufacturer

  19. Optical monitoring of complex dynamics of blood sedimentation and lymph flow in vessels

    Science.gov (United States)

    Tuchin, Valery V.

    2004-05-01

    In this paper a few examples of the complex behavior of biological systems detected by optical techniques are described. All examples are related to cell suspensions behavior in in vitro and in vivo studies. In vitro studies performing investigation of a fine structure of blood sedimentation process and establishing nonlinear features of blood sedimentation as disease prognostic parameters are overviewed. Three optical techniques: OCT, CW laser beam transverse synchronized transillumination method and spatially-modulated laser beam transillumination method were considered. In blood sedimentation studied by OCT the regular or irregular oscillations of the RBC/plasma boundary were observed. The functional properties of erythrocytes in patients with coronary heart disease by mean of spatially-modulated laser beam transillumination method to reveal the stages of the acute coronary syndrome formation are discussed. The laser speckle and intravital TV-microscopic techniques applied to in vivo studies of lymph flow in microvessels are overviewed. The hypothesis on the alternating-translation (shuttle-stream) character of lymph flow is discussed.

  20. Growth capacity of thermotolerant campylobacters in culture media supplemented with pig and cow blood

    OpenAIRE

    Álvaro Tresierra-Ayala; Manuel Navas; Josué Flores; Ramsés Perea; Juan Huanaquiri; María Bendayán; Heriberto Fernández

    2010-01-01

    In this work 60 thermotolerant Campylobacter strains (37 C. jejuni and 23 C. coli) isolated from the cows, pigs, chickens and ducks (15 strains of each type of animal) were used to establish their growth capacity on media containing cow or swine blood as potential substitutes of sheep or horse blood. The growth capacity was assessed by viable counts on cow and swine blood media, using the modified Miles and Misra method. Campylobacter strains showed better growth in the media supplemented wit...

  1. Processing of MRI images weighted in TOF for blood vessels analysis: 3-D reconstruction

    International Nuclear Information System (INIS)

    This paper presents a novel presents an approach based on differences of intensities for the identification of vascular structures in medical images from MRI studies of type time of flight method (TOF). The plating method hypothesis gave high intensities belonging to the vascular system image type TOF can be segmented by thresholding of the histogram. The enhanced vascular structures is performed using the filter Vesselness, upon completion of a decision based on fuzzy thresholding minimizes error in the selection of vascular structures. It will give a brief introduction to the vascular system problems and how the images have helped diagnosis, is summarized the physical history of the different imaging modalities and the evolution of digital images with computers. Segmentation and 3-D reconstruction became image type time of flight; these images are typically used in medical diagnosis of cerebrovascular diseases. The proposed method has less error in segmentation and reconstruction of volumes related to the vascular system, clear images and less noise compared with edge detection methods. (Author)

  2. Processing of MRI images weighted in TOF for blood vessels analysis: 3-D reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez D, J.; Cordova F, T. [Universidad de Guanajuato, Campus Leon, Departamento de Ingenieria Fisica, Loma del Bosque No. 103, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Cruz A, I., E-mail: hernandezdj.gto@gmail.com [CONACYT, Centro de Investigacion en Matematicas, A. C., Jalisco s/n, Col. Valenciana, 36000 Guanajuato, Gto. (Mexico)

    2015-10-15

    This paper presents a novel presents an approach based on differences of intensities for the identification of vascular structures in medical images from MRI studies of type time of flight method (TOF). The plating method hypothesis gave high intensities belonging to the vascular system image type TOF can be segmented by thresholding of the histogram. The enhanced vascular structures is performed using the filter Vesselness, upon completion of a decision based on fuzzy thresholding minimizes error in the selection of vascular structures. It will give a brief introduction to the vascular system problems and how the images have helped diagnosis, is summarized the physical history of the different imaging modalities and the evolution of digital images with computers. Segmentation and 3-D reconstruction became image type time of flight; these images are typically used in medical diagnosis of cerebrovascular diseases. The proposed method has less error in segmentation and reconstruction of volumes related to the vascular system, clear images and less noise compared with edge detection methods. (Author)

  3. Computer-assisted spatial reconstruction of cerebral blood vessels and intracranial aneurysms

    Directory of Open Access Journals (Sweden)

    Nikolić Igor M.

    2006-01-01

    Full Text Available Introduction. Today, many medical procedures are based on image analysis with the aim of providing accurate diagnosis and optimal treatment. The goal of this report was to present clinical implications of computer-assisted geometric design of carotid aneurysms. Material and methods. In this study, the three-dimensional reconstruction was based on the approximation power of the parametric spline function, which achieves interpolation and surface fitting of the arterial information obtained by conventional angiography. Two views of conventional angiograms (anterioposterior and lateral views were used with a personal computer and commercial software. Results. This method of three-dimensional generated images was applied in 45 cases of cerebral aneurysms in carotid bifurcation. 3D reconstructions were made in approximately 20 minutes. They contributed to assessing vascular structures, and it was possible to rotate the three-dimensional image in different angles. Conclusion. Three-dimensional reconstruction of cerebral vessels is very useful for discussing surgical strategies preoperatively. Furthermore, it could also be used in endovascular procedures. .

  4. Acellular matrices as tool for renal progenitor differentiation studies and tissue engineering of blood vessels

    OpenAIRE

    Zanusso, Ilenia

    2013-01-01

    AMs seem to be a very promising scaffold in TE and can be considered as temporary inductive site-appropriate templates to support the growth, differentiation, and function of the parenchymal cell population of each organ. Nowadays, TE techniques are used both to develop tissue substitutes ex vivo and as reliable tool to investigate cell behaviour, differentiation and proliferation in 3-dimentional environments. In this work the following two different projects have investigated both poten...

  5. Hard X-ray in-line outline imaging for blood vessels: first generation synchrotron radiation without contrast agents in vitro

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective: Phase-contrast X-ray imaging which reduces radiation exposure, is a promising technique for observing the inner structures of biological soft tissues without the aid of contrast agents.The present study intends to depict blood vessels of rabbits and human livers with hard X-ray in-line out line imaging without contrast agents using synchrotron radiation. Methods: All samples were fixed with formalin and sliced into 6 mm sections. The imaging experiments were performed with Fuji-IX80 films on the 4W1A light beam of the first generation synchrotron radiation in Beijing, China. The device of the ex periment, which supplies a maximum light spot size of 20× 10 mm was similar to that of in-line holography. The photon energy was set at 8 KeV and high quality imagines were obtained by altering the distance between the sample and the film. Results: The trees of rabbit-liver blood vessels and the curved vessels of the cirrhotic human liver were revealed on the images, where vessels < 20 μm in diameter were differentiated. Conclusion: These results show that the blood vessels of liver samples can be revealed by using hard X-ray in-line outline imaging with the first generation synchrotron radiation without contrast agents.

  6. Three-dimensional Gd-DTPA MR angiography of cerebral blood vessels

    International Nuclear Information System (INIS)

    Subtraction angiography based on three-dimensional fast MR imaging techniques using rephasing and dephasing gradient pulses is widely used. Similar angiograms can be obtained with three-dimensional gradient techniques before and after the administration of Gd-DTPA followed by imaging subtraction. As Gd-DTPA does not penetrate the blood-brain barrier, it does not alter brain images. Measurements were carried out in 14 patients with a 1.0-T whole-body imager (Siemens, Magnetom). Gd-DTPA angiography was superior to rephased-dephased angiography because of the higher signal intensity, lower noise due to short echo times, and high contrast for moving spins caused by Gd-DTPA

  7. Functional photoacoustic micro-imaging of cerebral hemodynamic changes in single blood vessels after photo-induced brain stroke

    Science.gov (United States)

    Liao, Lun-De; Chen, You-Yin; Lin, Chin-Teng; Li, Meng-Lin

    2013-03-01

    Studying the functional hemodynamic roles of individual cerebral cortical arterioles in maintaining both the structure and function of cortical regions during and after brain stroke in small animals is an important issue. Recently, functional photoacoustic microscopy (fPAM) has been proved as a reliable imaging technique to probe the total hemoglobin concentration (HbT), cerebral blood volume (CBV) and hemoglobin oxygen saturation (SO2) in single cerebral blood vessels of rats. Here, we report the application of fPAM associated with electrophysiology recordings to investigating functional hemodynamic changes in single cortical arterioles of rats with electrical forepaw stimulation after photo-induced ischemic stroke. Because of the weak optical focusing nature of our fPAM system, photo-induced ischemic stroke targeting single cortical arterioles can be easily conducted with simple adaptation. Functional HbT, CBV and SO2 changes associated with the induced stroke in selected arterioles from the anterior cerebral artery system were imaged with 36 x 65-μm spatial resolution. Experimental results showed that after photo-occlusion of a single arteriole, the functional changes of nearby arterioles in cerebral cortex only can be observed immediately after the stroke. After a few minutes of stroke onset, there are no significant functional changes under the forepaw stimulation, suggesting that alternate blood flow routes are not actively recruited. The fPAM with electrophysiology recordings complements existing imaging techniques and has the potential to offer a favorable tool for explicitly studying cerebral hemodynamics in small animal models of photo-indcued ischemic stroke.

  8. Cell-free cryopreserved arterial allografts from multiorgan donors: a new strategy to fabricate artificial blood vessels suited for peripheral vascular surgery

    OpenAIRE

    Papadopulos, Francesca Marzia

    2012-01-01

    Critical lower limb ischemia is a severe disease. A common approach is infrainguinal bypass. Synthetic vascular prosthesis, are good conduits in high-flow low-resistance conditions but have difficulty in their performance as small diameter vessel grafts. A new approach is the use of native decellularized vascular tissues. Cell-free vessels are expected to have improved biocompatibility when compared to synthetic and are optimal natural 3D matrix templates for driving stem cell growth and tiss...

  9. Real-time intraoperative full-range complex FD-OCT guided cerebral blood vessel identification and brain tumor resection in neurosurgery

    Science.gov (United States)

    Zhang, Kang; Huang, Yong; Pradilla, Gustavo; Tyler, Betty; Kang, Jin U.

    2011-03-01

    This work utilized an ultra-high-speed full-range complex-conjugate-free optical coherence tomography (FD-OCT) system to perform real-time intraoperative imaging to guide two common neurosurgical procedures: the cerebral blood vessel identification and the brain tumor resection. The cerebral blood vessel identification experiment is conducted ex vivo on human cadaver specimen. Specific cerebral arteries and veins in different positions of the specimen are visualized and the spatial relations between adjacent vessels are indentified through real-time 3D visualization. The brain tumor resection experiment is conducted in vivo on 9L gliomas established in rat brains. The normal brain-tumor margin can be clearly identified in depth of the tissue from sagittal, coronal and axial slices of the intraoperatively acquired 3D data set. The real-time full-range FD-OCT guided in vivo rat flank tumor resection is also conducted.

  10. Skeletal muscle fiber, nerve, and blood vessel breakdown in space-flown rats

    Science.gov (United States)

    Riley, D. A.; Ilyina-Kakueva, E. I.; Ellis, S.; Bain, J. L.; Slocum, G. R.; Sedlak, F. R.

    1990-01-01

    Histochemical and ultrastructural analyses were performed postflight on hind limb skeletal muscles of rats orbited for 12.5 days aboard the unmanned Cosmos 1887 biosatellite and returned to Earth 2 days before sacrifice. The antigravity adductor longus (AL), soleus, and plantaris muscles atrophied more than the non-weight-bearing extensor digitorum longus, and slow muscle fibers were more atrophic than fast fibers. Muscle fiber segmental necrosis occurred selectively in the AL and soleus muscles; primarily, macrophages and neutrophils infiltrated and phagocytosed cellular debris. Granule-rich mast cells were diminished in flight AL muscles compared with controls, indicating the mast cell secretion contributed to interstitial tissue edema. Increased ubiquitination of disrupted myofibrils implicated ubiquitin in myofilament degradation. Mitochondrial content and succinic dehydrogenase activity were normal, except for subsarcolemmal decreases. Myofibrillar ATPase activity of flight AL muscle fibers shifted toward the fast type. Absence of capillaries and extravasation of red blood cells indicated failed microcirculation. Muscle fiber regeneration from activated satellite cells was detected. About 17% of the flight AL end plates exhibited total or partial denervation. Thus, skeletal muscle weakness associated with spaceflight can result from muscle fiber atrophy and segmental necrosis, partial motor denervation, and disruption of the microcirculation.

  11. Collateral blood vessels in acute ischemic stroke: a physiological window to predict future outcomes

    Directory of Open Access Journals (Sweden)

    Heitor Castelo Branco Rodrigues Alves

    2016-01-01

    Full Text Available ABSTRACT Collateral circulation is a physiologic pathway that protects the brain against ischemic injury and can potentially bypass the effect of a blocked artery, thereby influencing ischemic lesion size and growth. Several recent stroke trials have provided information about the role of collaterals in stroke pathophysiology, and collateral perfusion has been recognized to influence arterial recanalization, reperfusion, hemorrhagic transformation, and neurological outcomes after stroke. Our current aim is to summarize the anatomy and physiology of the collateral circulation and to present and discuss a comprehensible review of the related knowledge, particularly the effects of collateral circulation on the time course of ischemic injury and stroke severity, as well as imaging findings and therapeutic implications.

  12. Three-dimensional growth of endothelial cells in the microgravity-based rotating wall vessel bioreactor.

    Science.gov (United States)

    Sanford, Gary L; Ellerson, Debra; Melhado-Gardner, Caroline; Sroufe, Angrla E; Harris-Hooker, Sandra

    2002-10-01

    We characterized bovine aortic endothelial cells (BAEC) continuously cultured in the rotating wall vessel (RWV) bioreactor for up to 30 d. Cultures grew as large tissue-like aggregates (containing 20 or more beads) after 30 d. These cultures appeared to be growing in multilayers around the aggregates, where single beads were covered with confluent BAEC, which displayed the typical endothelial cell (EC) morphology. The 30-d multibead aggregate cultures have a different and smoother surface when viewed under a higher-magnification scanning electron microscope. Transmission electron microscopy of these large BAEC aggregates showed that the cells were viable and formed multilayered sheets that were separated by an extracellular space containing matrix-like material. These three-dimensional cultures also were found to have a basal production of nitric oxide (NO) that was 10-fold higher for the RWV than for the Spinner flask bioreactor (SFB). The BAEC in the RWV showed increased basal NO production, which was dependent on the RWV rotation rate: 73% increase at 8 rpm, 262% increase at 15 rpm, and 500% increase at 20 rpm as compared with control SFB cultures. The addition of l-arginine to the RWV cultures resulted in a fourfold increase in NO production over untreated RWV cultures, which was completely blocked by L-NAME [N(G)-nitro-L-arginine-methylester]. Cells in the SFB responded similarly. The RWV cultures showed an increase in barrier properties with an up-regulation of tight junction protein expression. We believe that this study is the first report of a unique growth pattern for ECs, resulting in enhanced NO production and barrier properties, and it suggests that RWV provides a unique model for investigating EC biology and differentiated function. PMID:12703976

  13. Time-dependent effects of castration on the bladder function and histological changes in the bladder and blood vessels

    Directory of Open Access Journals (Sweden)

    Tomohiro Magari

    2014-06-01

    Full Text Available We examined the effect of androgens on bladder blood flow (BBF, bladder function and histological changes in castrated male rats. Male Wistar rats were classified into unoperated group (control group, groups castrated at the age of 8 weeks (group 8wPC and groups castrated at the age of 4 weeks (group 4wPC. Each rat was used at the age of 20 weeks. BBF was measured using fluorescent microspheres. Bladder cystometry was performed without anesthesia or restraint; the bladder was first irrigated with saline and then with 0.25% acetic acid (AA solution. Maximum voiding pressure and voiding interval were measured. The bladder and iliac artery were histologically examined for differences in smooth muscle and quantity of collagen fiber to analyze the effect of castration on the smooth muscle content. No differences were noted in BBF following castration. The voiding intervals for all groups were shortened (P < 0.001 following AA irrigation. No significant difference was noted in the maximum voiding pressure. Histological changes were observed in bladder and iliac artery. Smooth muscle/collagen ratio at the bladder was lower in groups 8wPC and 4wPC compared to the control group (P< 0.01, while that at the iliac artery was decreased in group 4wPC compared to the control group (P< 0.001. In conclusion, our findings indicate that castration does not alter BBF, but leads to histological changes in the bladder as well as its associated blood vessels.

  14. LYVE-1 is not restricted to the lymph vessels: expression in normal liver blood sinusoids and down-regulation in human liver cancer and cirrhosis.

    Science.gov (United States)

    Mouta Carreira, C; Nasser, S M; di Tomaso, E; Padera, T P; Boucher, Y; Tomarev, S I; Jain, R K

    2001-11-15

    Lymphatic vessel endothelial hyaluronan receptor (LYVE)-1 is thought to be restricted to lymph vessels and has been used as such to show that tumor lymphangiogenesis occurs on overexpression of lymphangiogenic factors in mouse tumor models. However, these studies have not yet been corroborated in human tumors. Here we show, first, that LYVE-1 is not exclusive to the lymph vessels. Indeed, LYVE-1 is also present in normal hepatic blood sinusoidal endothelial cells in mice and humans. Surprisingly, LYVE-1 is absent from the angiogenic blood vessels of human liver tumors and only weakly present in the microcirculation of regenerative hepatic nodules in cirrhosis, though both vessels are largely derived from the liver sinusoids. Second, we propose a novel approach to identify lymphatics in human and murine liver. By combining LYVE-1 and Prox 1 (a transcription factor) immunohistochemistry, we demonstrate that lymphatics are abundant in cirrhosis. In contrast, in human hepatocellular carcinoma and liver metastases, they are restricted to the tumor margin and surrounding liver. The absence of intratumor lymphatics in hepatocellular carcinomas and liver metastases may impair molecular and cellular transport in these tumors. Finally, the presence of LYVE-1 in liver sinusoidal endothelia suggests that LYVE-1 has functions beyond the lymph vascular system. PMID:11719431

  15. Blood Thinners

    Science.gov (United States)

    If you have some kinds of heart or blood vessel disease, or if you have poor blood flow to your brain, your doctor may recommend that you take a blood thinner. Blood thinners reduce the risk of heart ...

  16. Identification of pro-angiogenic markers in blood vessels from stroked-affected brain tissue using laser-capture microdissection

    Directory of Open Access Journals (Sweden)

    Baldellou Maribel

    2009-03-01

    Full Text Available Abstract Background Angiogenesis correlates with patient survival following acute ischaemic stroke, and survival of neurons is greatest in tissue undergoing angiogenesis. Angiogenesis is critical for the development of new microvessels and leads to re-formation of collateral circulation, reperfusion, enhanced neuronal survival and improved recovery. Results Here, we have isolated active (CD105/Flt-1 positive and inactive (CD105/Flt-1 minus (n=5 micro-vessel rich-regions from stroke-affected and contralateral tissue of patients using laser-capture micro-dissection. Areas were compared for pro- and anti-angiogenic gene expression using targeted TaqMan microfluidity cards containing 46 genes and real-time PCR. Further analysis of key gene de-regulation was performed by immunohistochemistry to define localization and expression patterns of identified markers and de novo synthesis by human brain microvessel endothelial cells (HBMEC was examined following oxygen-glucose deprivation (OGD. Our data revealed that seven pro-angiogenic genes were notably up-regulated in CD105 positive microvessel rich regions. These were, beta-catenin, neural cell adhesion molecule (NRCAM, matrix metalloproteinase-2 (MMP-2, tissue inhibitor of matrix metalloproteinase-1 (TIMP-1, hepatocyte growth factor-alpha (HGF-alpha, monocyte chemottractant protein-1 (MCP-1 and and Tie-2 as well as c-kit. Immunohistochemistry demonstrated strong staining of MMP-2, HGF-alpha, MCP-1 and Tie-2 in stroke-associated regions of active remodeling in association with CD105 positive staining. In vitro, OGD stimulated production of Tie-2, MCP-1 and MMP-2 in HBMEC, demonstrated a de novo response to hypoxia. Conclusion In this work we have identified concurrent activation of key angiogenic molecules associated with endothelial cell migration, differentiation and tube-formation, vessel stabilization and stem cell homing mechanisms in areas of revascularization. Therapeutic stimulation of these

  17. Smooth Muscle Cell Alignment and Phenotype Control by Melt Spun Polycaprolactone Fibers for Seeding of Tissue Engineered Blood Vessels

    Directory of Open Access Journals (Sweden)

    Animesh Agrawal

    2015-01-01

    Full Text Available A method has been developed to induce and retain a contractile phenotype for vascular smooth muscle cells, as the first step towards the development of a biomimetic blood vessel construct with minimal compliance mismatch. Melt spun PCL fibers were deposited on a mandrel to form aligned fibers of 10 μm in diameter. The fibers were bonded into aligned arrangement through dip coating in chitosan solution. This formed a surface of parallel grooves, 10 μm deep by 10 μm across, presenting a surface layer of chitosan to promote cell surface interactions. The aligned fiber surface was used to culture cells present in the vascular wall, in particular fibroblasts and smooth muscle cells. This topography induced “surface guidance” over the orientation of the cells, which adopted an elongated spindle-like morphology, whereas cells on the unpatterned control surface did not show such orientation, assuming more rhomboid shapes. The preservation of VSMC contractile phenotype on the aligned scaffold was demonstrated by the retention of α-SMA expression after several days of culture. The effect was assessed on a prototype vascular graft prosthesis fabricated from polylactide caprolactone; VSMCs aligned longitudinally along a fiberless tube, whereas, for the aligned fiber coated tubes, the VSMCs aligned in the required circumferential orientation.

  18. Evaluation of doxorubicin-loaded pH-sensitive polymeric micelle release from tumor blood vessels and anticancer efficacy using a dorsal skin-fold window chamber model

    OpenAIRE

    Jin, Zhe-Hu; Jin, Ming-Ji; Jiang, Chang-gao; Yin, Xue-zhe; Jin, Shuai-xing; Quan, Xiu-quan; Zhong-gao GAO

    2014-01-01

    Aim: To evaluation the doxorubicin (DOX)-loaded pH-sensitive polymeric micelle release from tumor blood vessels into tumor interstitium using an animal vessel visibility model, the so-called dorsal skin-fold window chamber model. Methods: DOX-loaded pH-sensitive polyHis-b-PEG micelles and DOX-loaded pH-insensitive PLLA-b-PEG micelles were prepared. The uptake of the micelles by MDA-MB-231 breast cancer cells in vitro and in vivo was examined using flow cytometry. The pharmacokinetic parameter...

  19. Hormones that Stimulate the Growth of Blood Cells.

    Science.gov (United States)

    Golde, David W.; Gasson, Judith C.

    1988-01-01

    Describes the nature and action of hematopoietic proteins which regulate the production of specific sets of blood cells. Discusses the production of these hematopoietins by recombinant-DNA methods in an effort to enable physicians to treat patients by eliciting production of specific types of blood cells. (CW)

  20. Uterine artery blood flow, fetal hypoxia and fetal growth

    OpenAIRE

    Browne, Vaughn A.; Julian, Colleen G.; Toledo-Jaldin, Lillian; Cioffi-Ragan, Darleen; Vargas, Enrique; Moore, Lorna G.

    2015-01-01

    Evolutionary trade-offs required for bipedalism and brain expansion influence the pregnancy rise in uterine artery (UtA) blood flow and, in turn, reproductive success. We consider the importance of UtA blood flow by reviewing its determinants and presenting data from 191 normotensive (normal, n = 125) or hypertensive (preeclampsia (PE) or gestational hypertension (GH), n = 29) Andean residents of very high (4100–4300 m) or low altitude (400 m, n = 37). Prior studies show that UtA blood flow i...

  1. Some mechanistic observations on the crack growth characteristics of pressure vessel and piping steels in PWR environment

    International Nuclear Information System (INIS)

    The fatigue crack growth behavior of A533B and A508 pressure vessel steel and AISI Types 304 and 316 steels used in reactor coolant piping have been studied in a pressurized water reactor environment at 2880C (5500F). The influence of stress ratio (P/sub min//P/sub max/), frequency, ramp times, specimen orientation and material microstructures were included in the study. While none of the materials showed evidence of static crack growth in the environment, the ferritic steels did show an enhanced fatigue crack growth rate at test frequencies of five cycles per minute and lower. Based on fractographic examinations the enhanced growth rate is not the result of environmentally induced intergranular or cleavage modes of crack propagation. Instead, striation spacing measurements were found to agree with the macroscopic crack growth rate, demonstrating a time dependent environmental interaction which introduces a frequency dependent enhancement of the mechanically developed striations. Crack growth experiments using hold times have confirmed the absence of any superimposed contribution of static crack growth components. Fatigue crack growth tests were conducted in an environment of Hydrogen Sulfide gas to establish the contribution of hydrogen embrittlement and will also be described

  2. Quantification of blood vessel calibre in retinal images of multi-ethnic school children using a model based approach.

    Science.gov (United States)

    Fraz, M M; Remagnino, P; Hoppe, A; Rudnicka, A R; Owen, C G; Whincup, P H; Barman, S A

    2013-01-01

    Changes and variation in retinal vessel width are related to vascular risk factors and prospectively related to cardiovascular disease in later life. Hence, assessment of vessel width may be a useful physio-marker and potential predictor of cardiovascular status. However, measurement of vessel calibre from retinal images is a challenging process to automate. This paper proposes an automated system to measure vessel calibre in retinal images, which is demonstrated in images of multi-ethnic school children. The diameter measurement is based on the detection of the centreline pixels from a vessel probability map image, determining the vessel orientation at these pixels, extracting the vessel segments and later using a two-dimensional model, which is optimized to fit various types of intensity profiles of vessel segments. The width is then estimated from parameters of the optimized model. The method is also quantitatively analyzed using monochromatic representations of different colour spaces. The algorithm is evaluated on a recently introduced public database CHASE_DB1, which is a subset of retinal images of multi-ethnic children from the Child Heart and Health Study in England (CHASE) dataset. Moreover, the precise estimation of retinal vascular widths is critical for epidemiologists to identify the risk factors. This work also introduces an interactive software tool for epidemiologists, with which retinal vessel calibre can be precisely marked. PMID:23410507

  3. New Strain Energy Functions of Blood Vessel (Ⅰ)%血管的新应变能函数(Ⅰ)

    Institute of Scientific and Technical Information of China (English)

    王寿梅; 李宁; 徐明

    2001-01-01

    首先提出并且验证了可被应用于大变形计算的描述血管非线性应力-应变关系的新的本构理论.其推导的数学基础是假设应力-应变关系可以用张量多项式来表示.通过对比可以发现,拟合结果与试验数据完全吻合,并且优于已有的指数形式的表达式.为降低Taylor展开式的次数,对级数进行了修正,并且针对不同的拟合过程和方法进行了讨论.%Investigation of the consequence of large deformation of blood vessel due to change in transmural pressure is crucial to the understanding of vein graft or other surgical operations involving blood vessel. The paper proposes and verifies new constitutive laws describing nonlinear stress-strain relation of orthogonal anisotropic materials. It can be used for large deformation calculation of blood vessels in the bio-mechanics regime. The derivation of the constitutive law is pure mathematical reasoning based on only one assumption that the stress-strain relation takes a polynomial form. Application is made in a blood vessel test. The correlation between the proposed formula and experimental data is excellent and better than that of the existing exponential expressions

  4. Effect of loading variables on the fatigue crack growth rate in SA508 C1.3 pressure vessel steel

    International Nuclear Information System (INIS)

    The influence of loading variable (stress ratio and frequency) and temperature on fatigue crack growth rate in SA508 cl.3 reactor pressure vessel steel was investigated in air environment. Fatigue crack growth tests were performed on compact tension (CT) specimens made to thickness 12.7mm. Compact tension test specimens were tested using sinusoidal waveform and the crack length was monitored by compliance method. Tests were conducted at two load ratios 0.1 and 0.5, at frequencies 10 and 1 Hz, at room temperature and 288 .deg. C. To investigate further details of the temperature effect, tests were conducted at R=0.5, f=1Hz in a range of temperature from room temperature to 400 .deg. C. The effect of R-ratio on the growth rate at each testing frequency and temperature shows that a significant influence of R-ratio on the fatigue crack growth rate is observed at the high temperature. The results also showed that the fatigue crack growth rate a given stress intensity level did not show distinct difference at RT and 120 .deg. C. However, at above 120 .deg. C, the fatigue crack growth rate increased as test temperature increases. In addition, it was found that the influence of the frequency on fatigue crack growth rate increased at higher temperatures. It is suggested that the frequency and temperature influence may be associated with environmental effects due to oxidation at crack tip

  5. A computational model of the fetal circulation to quantify blood redistribution in intrauterine growth restriction

    OpenAIRE

    Patricia Garcia-Canadilla; Rudenick, Paula A.; Fatima Crispi; Monica Cruz-Lemini; Georgina Palau; Oscar Camara; Eduard Gratacos; Bijnens, Bart H.

    2014-01-01

    Intrauterine growth restriction (IUGR) due to placental insufficiency is associated with blood flow redistribution in order to maintain delivery of oxygenated blood to the brain. Given that, in the fetus the aortic isthmus (AoI) is a key arterial connection between the cerebral and placental circulations, quantifying AoI blood flow has been proposed to assess this brain sparing effect in clinical practice. While numerous clinical studies have studied this parameter, fundamental understanding ...

  6. Relationship between leptin levels in maternal blood,amniotic fluid,arterial and venous cord blood and fetal growth

    Institute of Scientific and Technical Information of China (English)

    林丽莎; 薛昭卿; 宋岩峰; 何晓宇

    2003-01-01

    Objective:To study the relationship between leptin concentration and fetal growth.Methods: Levels of leptin in maternal serum, amniotic fluid, arterial and venouscord blood of 65 normal parturients (gestational age 37-42weeks) were measured by ra-dioimmunoassay (RIA) method. At the same time, maternal blood lipids were detected.Neonates were divided into three groups: small for gestational age (SGA) group (n=10), appropriate for gestational age (AGA) group (n=45), large for gestational age(LGA) group (n= 10). Statistical analysis was performed by t test, variance analysisand correlation analysis.Results: (1) There was no obvious correlation between leptin concentrations in ma-ternal serum and arterial/ venous cord blood, amniotic fluid, and also no correlationwith birth weight and placental weight (P>0.05). Maternal body mass index signifi-cantly correlated with birth weight and neonatal length and leptin levels in arterial andvenous cord blood (P<0.01). Leptin levels in arterial and venous cord blood positivelycorrelated significantly with placental and neonatal weight and body length (P<0.01)and negatively correlated with high density lipoprotein (P<0. 01). There was no obvi-ous correlation between fetal gender and leptin concentrations in maternal serum, arteri-al and venous cord blood and amniotic fluid; (2) Leptin levels in arterial and venouscord blood , placental weight in LGA group were significantly higher than those in SGAand AGA group (P<0.05). Among three groups, leptin concentrations in maternalblood were significantly higher than those in arterial and venous cord blood (P<0.05).Conclusions: (1)Fetal leptin is synthesized in uterus, born of itself and placenta.Leptin levels in arterial and venous cord blood are related to the intrauterine growthpattern. It might positively regulate birth weight and body fat content. (2)Either mater-nal or fetal leptin was not correlated with fetal gender. There is no gender difference infetal leptin

  7. A novel bispecific immunotoxin delivered by human bone marrow-derived mesenchymal stem cells to target blood vessels and vasculogenic mimicry of malignant gliomas

    Directory of Open Access Journals (Sweden)

    Zhang Y

    2015-06-01

    Full Text Available Yonghong Zhang,1,2 Xinlin Sun,1 Min Huang,1 Yiquan Ke,1 Jihui Wang,1 Xiao Liu1 1National Key Clinic Specialty, Neurosurgery Institute of Guangdong Province, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 2Department of Neurosurgery, First Hospital of Lanzhou University, Lanzhou, People’s Republic of China Background: In previous years, immunotoxins have been shown to be a greatly promising therapeutic tool for brain malignancies, such as gliomas. Human mesenchymal stem cells (hMSCs exhibit tropism to tumor tissue. However, the effect of bispecific immunotoxins in malignant gliomas is still unknown. The aim of this study was to investigate the function of bispecific immunotoxins in human malignant gliomas.Materials and methods: In the present study, the bispecific immunotoxin VEGF165-ephrin A1-PE38KDEL was established using deoxyribonucleic acid shuffling and cloning techniques. The VEGF165-ephrin A1-PE38KDEL was delivered by hMSCs to mouse malignant gliomas. The effects of the bispecific immunotoxins on glioma-derived blood vessels and vasculogenic mimicry to elucidate the molecular mechanisms underlying the antitumorigenic effects of immunotoxins were examined in vivo.Results: In vitro, transfected hMSCs significantly inhibited the cell viability of gliomas cell lines U87 and U251 in a dose-dependent manner compared with untransfected hMSCs (P<0.01. In vivo, the intratumoral injection of engineered hMSCs was effective at inhibiting tumor growth in a malignant glioma tumor model.Conclusion: The bispecific immunotoxin secreted from hMSCs acts as a novel strategy for improving treatment options for malignant gliomas in the clinic. Keywords: bispecific immunotoxin, human mesenchymal stem cells, ephrin A1, VEGF165, malignant glioma

  8. Erythroid cell growth and differentiation in vitro in the simulated microgravity environment of the NASA rotating wall vessel bioreactor

    Science.gov (United States)

    Sytkowski, A. J.; Davis, K. L.

    2001-01-01

    Prolonged exposure of humans and experimental animals to the altered gravitational conditions of space flight has adverse effects on the lymphoid and erythroid hematopoietic systems. Although some information is available regarding the cellular and molecular changes in lymphocytes exposed to microgravity, little is known about the erythroid cellular changes that may underlie the reduction in erythropoiesis and resultant anemia. We now report a reduction in erythroid growth and a profound inhibition of erythropoietin (Epo)-induced differentiation in a ground-based simulated microgravity model system. Rauscher murine erythroleukemia cells were grown either in tissue culture vessels at 1 x g or in the simulated microgravity environment of the NASA-designed rotating wall vessel (RWV) bioreactor. Logarithmic growth was observed under both conditions; however, the doubling time in simulated microgravity was only one-half of that seen at 1 x g. No difference in apoptosis was detected. Induction with Epo at the initiation of the culture resulted in differentiation of approximately 25% of the cells at 1 x g, consistent with our previous observations. In contrast, induction with Epo at the initiation of simulated microgravity resulted in only one-half of this degree of differentiation. Significantly, the growth of cells in simulated microgravity for 24 h prior to Epo induction inhibited the differentiation almost completely. The results suggest that the NASA RWV bioreactor may serve as a suitable ground-based microgravity simulator to model the cellular and molecular changes in erythroid cells observed in true microgravity.

  9. Dynamic analysis of crack growth and arrest in a pressure vessel subjected to thermal and pressure loading

    International Nuclear Information System (INIS)

    Predictions of crack arrest behaviour are performed for a cracked reactor pressure vessel under both thermal and pressure loading. The object is to compare static and dynamic calculations. The dynamic calculations are made using an explicit finite-element technique where crack growth is simulated by gradual nodal release. Three different load cases and the effect of different velocity dependence on the crack-propagation toughness are studied. It is found that for the analysed cases the static analysis is slightly conservative, thus justifying its use for these problems. (author)

  10. PDGF-C induces maturation of blood vessels in a model of glioblastoma and attenuates the response to anti-VEGF treatment.

    Directory of Open Access Journals (Sweden)

    Emmanuelle di Tomaso

    Full Text Available Recent clinical trials of VEGF inhibitors have shown promise in the treatment of recurrent glioblastomas (GBM. However, the survival benefit is usually short-lived as tumors escape anti-VEGF therapies. Here we tested the hypothesis that Platelet Derived Growth Factor-C (PDGF-C, an isoform of the PDGF family, affects GBM progression independent of VEGF pathway and hinders anti-VEGF therapy.We first showed that PDGF-C is present in human GBMs. Then, we overexpressed or downregulated PDGF-C in a human GBM cell line, U87MG, and grew them in cranial windows in nude mice to assess vessel structure and function using intravital microscopy. PDGF-C overexpressing tumors had smaller vessel diameters and lower vascular permeability compared to the parental or siRNA-transfected tumors. Furthermore, vessels in PDGF-C overexpressing tumors had more extensive coverage with NG2 positive perivascular cells and a thicker collagen IV basement membrane than the controls. Treatment with DC101, an anti-VEGFR-2 antibody, induced decreases in vessel density in the parental tumors, but had no effect on the PDGF-C overexpressing tumors.These results suggest that PDGF-C plays an important role in glioma vessel maturation and stabilization, and that it can attenuate the response to anti-VEGF therapy, potentially contributing to escape from vascular normalization.

  11. Evaluation of the integrity of domestic reactor pressure vessel steel through crack growth rate meaurements in simulated LWR water environment

    International Nuclear Information System (INIS)

    In simulated LWR conditions Fatigue Crack Growth Rate(FCGR) tests were performed to assess the integrity of domestic reactor pressure vessel material. Autoclave and circulating-water-loop were used to simulate LWR conditions. Test variables were Load-Frequency(LF) and Dissolved-Oxygen(DO) content. There was little environmental effect on FCGR at low DO or high LF conditions. Very high FCGR was enhanced at high DO condition, the enhancement of FCGR increased as LF decreased. In fractography study, Environmentally Assisted Crack(EAC), such as semi-cleavage and inter-granular crack, was found at only high DO condition, high FCGR was related to EAC. The FCGR results of domestic material were compared to ASME code and relative safety margin was calculated by a simple analysis of fatigue crack growth during plant operating time. The safety margin of domestic material was about 10 % higher in comparison with ASME code

  12. The effects of accelerated growth rates and estrogen implants in prepubertal Holstein heifers on growth, feed efficiency, and blood parameters.

    Science.gov (United States)

    Lammers, B P; Heinrichs, A J; Kensinger, R S

    1999-08-01

    Sixty-eight Holstein heifers were used to determine the effects of accelerated growth rates by increased nutrient intake and estrogen implants on feed efficiency, structural growth, and blood parameters in heifers between 19 and 39 wk of age. At the beginning of the treatment period, the heifers were assigned to one of four treatment groups by using a randomized complete block design in a 2 x 2 factorial arrangement. The treatments were standard growth rate (700 g/d), accelerated growth rate (1000 g/d), standard growth rate with an estradiol implant, and accelerated growth rate with an estradiol implant. All heifers received the same diet, but dry matter intake was adjusted weekly to achieve the target rate of gain. Accelerating heifer growth rates from 705 to 1007 g/d improved feed efficiency 5.1%, increased the rate of withers height, heart girth, and hip width growth 12, 27, and 27%, respectively, and body condition scores 0.25 points. Estradiol implants improved feed efficiency 2.4% and decreased the rate of withers height 6% and heart girth growth 3.5%. Increased nutrient intake and average daily gain depressed mean plasma growth hormone and urea nitrogen content 17 and 7%, respectively, while elevating insulin-like growth factor-1 levels by 10%. Estradiol implants increased mean plasma growth hormone content by 29% and insulin-like growth factor-1 levels by 17%, but decreased urea nitrogen content by 11%. Feeding prepubertal heifers for accelerated growth rates increased structural growth with a small increase in body condition, whereas estradiol implants improved feed efficiency and decreased the growth rate of withers height and heart girth without affecting the rate of hip width growth. PMID:10480101

  13. Specific Accumulation of Tumor-Derived Adhesion Factor in Tumor Blood Vessels and in Capillary Tube-Like Structures of Cultured Vascular Endothelial Cells

    Science.gov (United States)

    Akaogi, Kotaro; Okabe, Yukie; Sato, Junji; Nagashima, Yoji; Yasumitsu, Hidetaro; Sugahara, Kazuyuki; Miyazaki, Kaoru

    1996-08-01

    Tumor-derived adhesion factor (TAF) was previously identified as a cell adhesion molecule secreted by human bladder carcinoma cell line EJ-1. To elucidate the physiological function of TAF, we examined its distribution in human normal and tumor tissues. Immunochemical staining with an anti-TAF monoclonal antibody showed that TAF was specifically accumulated in small blood vessels and capillaries within and adjacent to tumor nests, but not in those in normal tissues. Tumor blood vessel-specific staining of TAF was observed in various human cancers, such as esophagus, brain, lung, and stomach cancers. Double immunofluorescent staining showed apparent colocalization of TAF and type IV collagen in the vascular basement membrane. In vitro experiments demonstrated that TAF preferentially bound to type IV collagen among various extracellular matrix components tested. In cell culture experiments, TAF promoted adhesion of human umbilical vein endothelial cells to type IV collagen substrate and induced their morphological change. Furthermore, when the endothelial cells were induced to form capillary tube-like structures by type I collagen, TAF and type IV collagen were exclusively detected on the tubular structures. The capillary tube formation in vitro was prevented by heparin, which inhibited the binding of TAF to the endothelial cells. These results strongly suggest that TAF contributes to the organization of new capillary vessels in tumor tissues by modulating the interaction of endothelial cells with type IV collagen.

  14. Blood (For Parents)

    Science.gov (United States)

    ... Story" 5 Things to Know About Zika & Pregnancy Blood KidsHealth > For Parents > Blood Print A A A ... about the mysterious, life-sustaining fluid called blood. Blood Basics Two types of blood vessels carry blood ...

  15. A New Method of Retarding Fatigue Crack Growth on Pressure Vessels

    Institute of Scientific and Technical Information of China (English)

    Jianzhong YIN; Yanyan WANG; Xinwei DING

    2001-01-01

    An artificial wedge to retard fatigue crack growth in tension has been investigated. The results show that an artificial wedge can reduce the growth rate of fatigue crack on Surface fatigue crack and, the fatigue crack growth behavior is essentially similar in-depth and width directions. Based on a theoretical analysis, a model for the effective crack growth parameter △Keff is presented. It is shown that the relationships between the calculated △Keff value and crack speed are almost the same as those of cracked specimens without a wedge. Therefore this model can be applied to estimate retardation behavior.

  16. Blood vessel hyperpermeability and pathophysiology in human tumour xenograft models of breast cancer: a comparison of ectopic and orthotopic tumours

    Directory of Open Access Journals (Sweden)

    Ho Karyn S

    2012-12-01

    Full Text Available Abstract Background Human tumour xenografts in immune compromised mice are widely used as cancer models because they are easy to reproduce and simple to use in a variety of pre-clinical assessments. Developments in nanomedicine have led to the use of tumour xenografts in testing nanoscale delivery devices, such as nanoparticles and polymer-drug conjugates, for targeting and efficacy via the enhanced permeability and retention (EPR effect. For these results to be meaningful, the hyperpermeable vasculature and reduced lymphatic drainage associated with tumour pathophysiology must be replicated in the model. In pre-clinical breast cancer xenograft models, cells are commonly introduced via injection either orthotopically (mammary fat pad, MFP or ectopically (subcutaneous, SC, and the organ environment experienced by the tumour cells has been shown to influence their behaviour. Methods To evaluate xenograft models of breast cancer in the context of EPR, both orthotopic MFP and ectopic SC injections of MDA-MB-231-H2N cells were given to NOD scid gamma (NSG mice. Animals with matched tumours in two size categories were tested by injection of a high molecular weight dextran as a model nanocarrier. Tumours were collected and sectioned to assess dextran accumulation compared to liver tissue as a positive control. To understand the cellular basis of these observations, tumour sections were also immunostained for endothelial cells, basement membranes, pericytes, and lymphatic vessels. Results SC tumours required longer development times to become size matched to MFP tumours, and also presented wide size variability and ulcerated skin lesions 6 weeks after cell injection. The 3 week MFP tumour model demonstrated greater dextran accumulation than the size matched 5 week SC tumour model (for P  Conclusions Dextran accumulation and immunostaining results suggest that small MFP tumours best replicate the vascular permeability required to observe the EPR effect

  17. Blood vessel hyperpermeability and pathophysiology in human tumour xenograft models of breast cancer: a comparison of ectopic and orthotopic tumours

    International Nuclear Information System (INIS)

    Human tumour xenografts in immune compromised mice are widely used as cancer models because they are easy to reproduce and simple to use in a variety of pre-clinical assessments. Developments in nanomedicine have led to the use of tumour xenografts in testing nanoscale delivery devices, such as nanoparticles and polymer-drug conjugates, for targeting and efficacy via the enhanced permeability and retention (EPR) effect. For these results to be meaningful, the hyperpermeable vasculature and reduced lymphatic drainage associated with tumour pathophysiology must be replicated in the model. In pre-clinical breast cancer xenograft models, cells are commonly introduced via injection either orthotopically (mammary fat pad, MFP) or ectopically (subcutaneous, SC), and the organ environment experienced by the tumour cells has been shown to influence their behaviour. To evaluate xenograft models of breast cancer in the context of EPR, both orthotopic MFP and ectopic SC injections of MDA-MB-231-H2N cells were given to NOD scid gamma (NSG) mice. Animals with matched tumours in two size categories were tested by injection of a high molecular weight dextran as a model nanocarrier. Tumours were collected and sectioned to assess dextran accumulation compared to liver tissue as a positive control. To understand the cellular basis of these observations, tumour sections were also immunostained for endothelial cells, basement membranes, pericytes, and lymphatic vessels. SC tumours required longer development times to become size matched to MFP tumours, and also presented wide size variability and ulcerated skin lesions 6 weeks after cell injection. The 3 week MFP tumour model demonstrated greater dextran accumulation than the size matched 5 week SC tumour model (for P < 0.10). Immunostaining revealed greater vascular density and thinner basement membranes in the MFP tumour model 3 weeks after cell injection. Both the MFP and SC tumours showed evidence of insufficient lymphatic drainage

  18. Soluble vascular endothelial growth factor in various blood transfusion components

    DEFF Research Database (Denmark)

    Nielsen, Hans Jørgen; Werther, K; Mynster, T;

    1999-01-01

    of platelet-derived soluble plasminogen activator inhibitor type 1 (sPAI-1) was determined by an EIA in the same samples. Finally, the extracellular accumulation of sVEGF was determined in nonfiltered WB and SAGM blood during storage for 35 days and in BCP pools during storage for 7 days. RESULTS: In...... the healthy volunteers, median total sVEGF content was 97 (range, 20-303) pg per mL in serum and 19 (13-37) pg per mL in plasma (n = 12, p < 0.002) and 445 (280-990) pg per mL in lysed cells. Median total sPAI-1 content was 94 (64-127) ng per mL in serum, 8 (6-11) ng per mL in citrated plasma, and 95...

  19. Visualization of angiogenic vessels by synchrotron radiation microangiography

    International Nuclear Information System (INIS)

    The usefulness of synchrotron radiation microangiography for evaluating angiogenic vessels in regenerative therapy is illustrated. In a rabbit model of microvascular myocardial ischemia, angiogenic vessels in the heart were well visualized. In a rabbit model of hindlimb ischemia, vessel-regenerative therapy with fibroblast growth factor 4-gene incorporated to gelatin hydrogel well ameliorated muscle necrosis. Synchrotron radiation microangiography confirmed significant blood flow increase to adenosine administration in these treated rabbits (vascular responsiveness), but not in the control. Thus, synchrotron radiation microangiography is shown to be useful for the depiction, quantification and evaluation of angiogenic vessels in reproductive therapy. (author)

  20. Stress Corrosion Cracking and Fatigue Crack Growth Studies Pertinent to Spacecraft and Booster Pressure Vessels

    Science.gov (United States)

    Hall, L. R.; Finger, R. W.

    1972-01-01

    This experimental program was divided into two parts. The first part evaluated stress corrosion cracking in 2219-T87 aluminum and 5Al-2.5Sn (ELI) titanium alloy plate and weld metal. Both uniform height double cantilever beam and surface flawed specimens were tested in environments normally encountered during the fabrication and operation of pressure vessels in spacecraft and booster systems. The second part studied compatibility of material-environment combinations suitable for high energy upper stage propulsion systems. Surface flawed specimens having thicknesses representative of minimum gage fuel and oxidizer tanks were tested. Titanium alloys 5Al-2.5Sn (ELI), 6Al-4V annealed, and 6Al-4V STA were tested in both liquid and gaseous methane. Aluminum alloy 2219 in the T87 and T6E46 condition was tested in fluorine, a fluorine-oxygen mixture, and methane. Results were evaluated using modified linear elastic fracture mechanics parameters.

  1. IgG/IgE bullous pemphigoid with CD45 lymphocytic reactivity to dermal blood vessels, nerves and eccrine sweat glands

    Directory of Open Access Journals (Sweden)

    Ana Maria Abreu-Velez

    2010-01-01

    Full Text Available Context: Bullous pemphigoid (BP, the most common autoimmune blistering disease, is mediated by autoantibodies. BP primarily affects the elderly and is characterized by the development of urticarial plaques surmounted by subepidermal blisters, and the deposition of immunoglobulins and complement at the basement membrane zone (BMZ of the skin. BP is immunologically characterized by the development of autoantibodies targeting two structural proteins of the hemidesmosomes, BP180 (collagen XVII and BP230 (BPAG1. Case Report: A 63 -year-old Caucasian female patient was evaluated for a 4 day history of several itching, erythematous blisters on her extremities. Biopsies for hematoxylin and eosin (H&E examination, as well as Periodic acid-Schiff (PAS, immunohistochemistry (IHC and direct immunofluorescence (DIF analysis were performed. Results: H&E demonstrated a subepidermal blister, with partial re-epithelialization of the blister floor. Within the blister lumen, numerous neutrophils were present, with occasional eosinophils and lymphocytes also noted. Within the dermis, a mild, superficial, perivascular and periadnexal infiltrate of lymphocytes, histiocytes and occasional eosinophils was identified, with mild perivascular leukocytoclastic debris. The PAS stain was positive at the BMZ, and around selected blood vessels, nerves and sweat glands. DIF revealed linear deposits of IgG and Complement/C3 and fibrinogen at the BMZ, and around selected dermal nerves, blood vessels and sweat glands. Strong granular deposits of IgE were also observed, colocalizing with monoclonal antibodies to Collagen IV (CIV. By IHC, positive CD45 staining of lymphocytes was seen surrounding selected dermal blood vessels, eccrine sweat glands, and nerves. Conclusion : The patient displayed IgG, IgE, and fibrinogen autoantibodies against the BMZ, as well as around some dermal nerves and sweat glands; their binding in the skin could trigger complement activation. In addition, the

  2. Lung fractional moving blood volume in normally grown and growth restricted foetuses.

    OpenAIRE

    Hernandez-Andrade, Edgar; Thuring, Ann; Jansson, Tomas; Lingman, Göran; Marsal, Karel

    2004-01-01

    Objective: To examine foetal lung blood perfusion using power Doppler ultrasound (PDU) and to compare fractional moving blood volume (FMBV) and mean pixel intensity (MPI) estimations in the lungs of normally grown (NG) foetuses and foetuses with intrauterine growth restriction (IUGR) and also to correlate foetal lung FMBV and MPI with respiratory complications after birth. Methods: Lungs of 47 NG and 25 IUGR foetuses after 32 weeks of gestation were examined with PDU. FMBV and MPI were...

  3. Prospect for vaginal delivery of growth restricted fetuses with abnormal umbilical artery blood flow.

    OpenAIRE

    Li, Hui; Gudmundsson, Saemundur; Olofsson, Per

    2003-01-01

    Background. The best mode of delivery in cases of intrauterine growth restriction (IUGR) with umbilical artery blood flow changes is not well elucidated. Objective. To evaluate outcome in IUGR with umbilical artery blood flow changes planned for vaginal delivery after a negative oxytocin challenge test (OCT). Methods. In 84 term singleton pregnancies with suspected IUGR and no unanimous indication for abdominal delivery, Doppler velocimetry and OCT were performed. Positive OCT c...

  4. Circulating Fibronectin Controls Tumor Growth

    Directory of Open Access Journals (Sweden)

    Anja von Au

    2013-08-01

    Full Text Available Fibronectin is ubiquitously expressed in the extracellular matrix, and experimental evidence has shown that it modulates blood vessel formation. The relative contribution of local and circulating fibronectin to blood vessel formation in vivo remains unknown despite evidence for unexpected roles of circulating fibronectin in various diseases. Using transgenic mouse models, we established that circulating fibronectin facilitates the growth of bone metastases by enhancing blood vessel formation and maturation. This effect is more relevant than that of fibronectin produced by endothelial cells and pericytes, which only exert a small additive effect on vessel maturation. Circulating fibronectin enhances its local production in tumors through a positive feedback loop and increases the amount of vascular endothelial growth factor (VEGF retained in the matrix. Both fibronectin and VEGF then cooperate to stimulate blood vessel formation. Fibronectin content in the tumor correlates with the number of blood vessels and tumor growth in the mouse models. Consistent with these results, examination of three separate arrays from patients with breast and prostate cancers revealed that a high staining intensity for fibronectin in tumors is associated with increased mortality. These results establish that circulating fibronectin modulates blood vessel formation and tumor growth by modifying the amount of and the response to VEGF. Furthermore, determination of the fibronectin content can serve as a prognostic biomarker for breast and prostate cancers and possibly other cancers.

  5. Development of a fast ultrasonic three-dimensional imaging system for diagnosing blood vessels of artificial-kidney-dialyzed patients

    Science.gov (United States)

    Akahane, Mutsuhiro; Mochizuki, Takashi; Yamashita, Yuko; Kasai, Chihiro; Kobayashi, Masayuki; Kishino, Osamu; Ogawa, Tomoya

    2001-05-01

    It is very important to observe the vessels of the patient who are dialyzed artificially. An X-ray examination using contrast medium injected to the patient has been used for this purpose up to the present, but sometimes the examination has a risk of radiation damage. Therefore, we developed a safe and easy-to-use system in which 3D images of the vessels in the patients are reconstructed very quick from ultrasonic echoes. In this system, a view point for 3D rendering is set on the above position of the ultrasonic transducer, and a ray for the rendering is coincided with an ultrasonic beam. These features enable 3D images to be gradually reconstructed in real time while the echoes are being received. A magnetic position sensor system and a special 3D scanner which was developed were adopted for acquiring 3D echo data. In signal processing, intensity inversion technology is carried out before the 3D rendering process in order to detect and emphasize the vessels. With this system, we have acquired echo signals from the vessels in the arm of kidney dialyzed patients and made similar 3D images of X-ray angiography with the echoes in a short time such as 4 to 8 seconds.

  6. A fully-automatic locally adaptive thresholding algorithm for blood vessel segmentation in 3D digital subtraction angiography.

    Science.gov (United States)

    Boegel, Marco; Hoelter, Philip; Redel, Thomas; Maier, Andreas; Hornegger, Joachim; Doerfler, Arnd

    2015-08-01

    Subarachnoid hemorrhage due to a ruptured cerebral aneurysm is still a devastating disease. Planning of endovascular aneurysm therapy is increasingly based on hemodynamic simulations necessitating reliable vessel segmentation and accurate assessment of vessel diameters. In this work, we propose a fully-automatic, locally adaptive, gradient-based thresholding algorithm. Our approach consists of two steps. First, we estimate the parameters of a global thresholding algorithm using an iterative process. Then, a locally adaptive version of the approach is applied using the estimated parameters. We evaluated both methods on 8 clinical 3D DSA cases. Additionally, we propose a way to select a reference segmentation based on 2D DSA measurements. For large vessels such as the internal carotid artery, our results show very high sensitivity (97.4%), precision (98.7%) and Dice-coefficient (98.0%) with our reference segmentation. Similar results (sensitivity: 95.7%, precision: 88.9% and Dice-coefficient: 90.7%) are achieved for smaller vessels of approximately 1mm diameter. PMID:26736679

  7. Standardization of Blood Growth Hormone Levels Measured by Different Kits Using a Linear Structural Relationship

    OpenAIRE

    Saito, Tomohiro; Tachibana, Katsuhiko; Shimatsu, Akira; Katsumata, Noriyuki; HIZUKA, Naomi; Fujieda, Kenji; Yokoya, Susumu; Tanaka, Toshiaki

    2006-01-01

    Accurate and reliable determination of blood growth hormone level is essential in the diagnosis and treatment of short stature children. However, measured levels differed considerably among measurement kits available in Japan until 2003. Therefore, standardization of the measured values was attempted by measuring growth hormone levels in a sample of healthy adult individuals every year using the different kits. A standardization equation was developed for each kit through linear structural re...

  8. P/Q-type and T-type voltage-gated calcium channels are involved in the contraction of mammary and brain blood vessels from hypertensive patients

    DEFF Research Database (Denmark)

    Thuesen, A D; Lyngsø, K S; Rasmussen, L;

    2016-01-01

    AIM: Calcium channel blockers are widely used in cardiovascular diseases. Besides L-type channels, T- and P/Q-type calcium channels are involved in the contraction of human renal blood vessels. It was hypothesized that T- and P/Q-type channels are involved in the contraction of human brain and...... P/Q-type antagonist ω-agatoxin IVA (10(-8) mol L(-1) ) and the T-type calcium blocker mibefradil (10(-7) mol L(-1) ) inhibited KCl depolarization-induced contraction in mammary arteries from hypertensive patients with no effect on blood vessels from normotensive patients. ω-Agatoxin IVA decreased...... contraction in cerebral arterioles from hypertensive patients. L-type blocker nifedipine abolished the contraction in mammary arteries. PCR analysis showed expression of P/Q-type (Cav 2.1), T-type (Cav 3.1 and Cav 3.2) and L-type (Cav 1.2) calcium channels in mammary and cerebral arteries. Immunohistochemical...

  9. Histamine H3 and H4 receptor ligands modify vascular histamine levels in normal and arthritic large blood vessels in vivo.

    Science.gov (United States)

    Kyriakidis, Konstantinos; Zampeli, Evangelia; Palaiologou, Marina; Tiniakos, Dina; Tiligada, Ekaterini

    2015-01-01

    Growing evidence associates histamine with arthritis, but its implication in shaping vascular function in chronic inflammation remains largely elusive. This study explored the involvement of vascular histamine in the extra-articular responses in peripheral large blood vessels using a rat model of adjuvant-induced arthritis. Histamine levels were increased in the abdominal aorta and the inferior vena cava of arthritic animals. Contrary to the H1 receptor antagonist dimetindene, histamine induction was observed following administration of the H3 and H4 receptor ligands GSK334429 and JNJ7777120, respectively. In arthritis, prophylactic treatment with GSK334429 partially attenuated the clinical signs and restored basal histamine levels only in the abdominal aorta. This study is the first to implicate the H3 and H4 receptors in a concerted constitutive regulation of basal vascular histamine in the rat large blood vessels and to identify the H3 receptor as a component that may influence arterial histamine during the onset of arthritis. PMID:25359709

  10. 组织工程人工血管的临床应用研究进展%Clinical testing for tissue engineering blood vessel

    Institute of Scientific and Technical Information of China (English)

    孙本义; 陈学明

    2008-01-01

    To seek the ideal replacing grafts of blood vessel,many different methods of tissue engineering blood vessel(TEBV)have been created,such as collagen gel-based,biodegradable scaffold-based,self-assembled vascular grafts,and peritoneal and pleural cavities as bioreactors to grow autologous vascular grafts,etc.Some TEBVs have partially or completely met the requirements for clinic,even have applied in clinic.In this article reviewed,the models with better characters in big animals and clinical tests,and discussed the current problems of TEBV and looked forward to future clinical application.%为了寻找理想的血管替代物,涌现很多组织工程血管构建方法 ,如动物蛋白凝胶支架细胞种植,可降解支架细胞种植,组织片层组装,胸、腹腔生物反应器管芯诱导等.有的已部分或完全满足临床应用条件或已应用于临床,本文对大动物试验和临床应用中表现性能较好的构建模型加以综述,并探讨目前研究中的问题及对未来的展望.

  11. A software application for comparing large numbers of high resolution MALDI-FTICR MS spectra demonstrated by searching candidate biomarkers for glioma blood vessel formation

    Directory of Open Access Journals (Sweden)

    Smitt Peter

    2008-03-01

    Full Text Available Abstract Background A Java™ application is presented, which compares large numbers (n > 100 of raw FTICR mass spectra from patients and controls. Two peptide profile matrices can be produced simultaneously, one with occurrences of peptide masses in samples and another with the intensity of common peak masses in all the measured samples, using the peak- and background intensities of the raw data. In latter way, more significantly differentially expressed peptides are found between groups than just using the presence or absence in samples of common peak masses. The software application is tested by searching angiogenesis related proteins in glioma by comparing laser capture micro dissected- and enzymatic by trypsin digested tissue sections. Results By hierarchical clustering of the presence-absence matrix, it appears that proteins, such as hemoglobin alpha and delta subunit, fibrinogen beta and gamma chain precursor, tubulin specific chaperone A, epidermal fatty acid binding protein, neutrophil gelatinase-associated lipocalin precursor, peptidyl tRNA hydrolase 2 mitochondrial precursor, placenta specific growth hormone, and zinc finger CCHC domain containing protein 13 are significantly different expressed in glioma vessels. The up-regulated proteins in the glioma vessels with respect to the normal vessels determined by the Wilcoxon-Mann-Whitney test on the intensity matrix are vimentin, glial fibrillary acidic protein, serum albumin precursor, annexin A5, alpha cardiac and beta actin, type I cytoskeletal 10 keratin, calcium binding protein p22, and desmin. Peptide masses of calcium binding protein p22, Cdc42 effector protein 3, fibronectin precursor, and myosin-9 are exclusively present in glioma vessels. Some peptide fragments of non-muscular myosin-9 at the C-terminus are strongly up-regulated in the glioma vessels with respect to the normal vessels. Conclusion The less rigorous than in general used commercial propriety software de

  12. Role of macrophages and lymphocytes in morphogenesis of features of blood vessel in patients with metabolic syndrome complicated by stroke

    OpenAIRE

    Chuiko N.Ya.

    2013-01-01

    Background. The main morphological substrate of arterial disease in the metabolic syndrome is atherosclerosis, which morphogenesis is studied insufficiently. Objective. To estimate the role of macrophages and lymphocytes in the morphogenesis of changes of cerebral arteries in patients with metabolic syndrome complicated by ischemic and hemorrhagic stroke. Methods. We investigated brain vessels of 30 deaths from ischemic stroke, 30 - with hemorrhagic stroke on the background of metabolic syndr...

  13. Thiazine Red(+) platelet inclusions in Cerebral Blood Vessels are first signs in an Alzheimer's Disease mouse model.

    Science.gov (United States)

    Kniewallner, Kathrin M; Wenzel, Daniela; Humpel, Christian

    2016-01-01

    Strong evidence shows an association between cerebral vascular diseases and Alzheimer´s disease (AD). In order to study the interaction of beta-amyloid (Aβ) plaques with brain vessels, we crossbred an AD mouse model (overexpressing amyloid precursor protein with the Swedish-Dutch-Iowa mutations, APP_SweDI) with mice expressing green fluorescent protein (GFP) under the flt-1/VEGFR1 promoter in vessels (GFP_FLT1). Our data show, that only very few Aβ plaques were seen in 4-months old mice, focused in the mammillary body and in the lateral septal nucleus. The number of plaques markedly increased with age being most prominent in 12-months old mice. Thiazine Red was used to verify the plaques. Several Thiazine Red(+) inclusions were found in GFP(+) vessels, but only in non-perfused 4-months old mice. These inclusions were verified by Resorufin stainings possibly representing cerebral amyloid angiopathy. The inclusions were also seen in non-crossbred APP_SweDI but not in wildtype and GFP_FLT1 mice. In order to characterize these inclusions Flow Cytometry (FACS) analysis demonstrated that platelets were specifically stained by Thiazine Red(+), more pronounced when aggregated. In conclusion, our data show that Thiazine Red(+) inclusions representing aggregated platelets are a first pathological sign in AD before plaque development and may become important therapeutic targets in early AD. PMID:27345467

  14. The Development of Blood and Lymph Vessels of Human Parathyroid Glands in Embryonal, Fetal and Postnatal Period

    OpenAIRE

    Pezerović-Panijan, R.; Grbeša, Đ.; Banek, Lj.; Ježek, D.; Pezerović, Dž.; Čavčić, J.; Čanić, R.

    2001-01-01

    The aim of the article is to investigate the development of blood and lymph systems in human parathyroid glands in prenatal and postnatal periods. The first capillaries are observed in these glands already in the lunar month 2. At the middle of pregnancy blood supply is increased, being extremely abundant in lunar months 9 and 10, as well as during the first year of life. As parts of the lymph system, intercellular lymph spaces are noticed in the parathyroid glands already in t...

  15. HYDROGEN ABSORPTION INDUCED SLOW CRACK GROWTH IN AUSTENITIC STAINLESS STEELS FOR PETROCHEMICAL PRESSURE VESSEL INDUSTRIES

    OpenAIRE

    Ronnie Higuchi Rusli

    2010-01-01

    Type 304L and type 309 austenitic stainless steels were tested either by exposed to gaseous hydrogen or undergoing polarized cathodic charging. Slow crack growth by straining was observed in type 304L, and the formation of α‘ martensite was indicated to be precursor for such cracking. Gross plastic deformation was observed at the tip of the notch, and a single crack grew slowly from this region in a direction approximately perpendicular to the tensile axis. Martensite formation is not a neces...

  16. Requirement of vasculogenesis and blood circulation in late stages of liver growth in zebrafish

    Directory of Open Access Journals (Sweden)

    Wohland Thorsten

    2008-09-01

    Full Text Available Abstract Background Early events in vertebrate liver development have been the major focus in previous studies, however, late events of liver organogenesis remain poorly understood. Liver vasculogenesis in vertebrates occurs through the interaction of endoderm-derived liver epithelium and mesoderm-derived endothelial cells (ECs. In zebrafish, although it has been found that ECs are not required for liver budding, how and when the spatio-temporal pattern of liver growth is coordinated with ECs remains to be elucidated. Results To study the process of liver development and vasculogenesis in vivo, a two-color transgenic zebrafish line Tg(lfabf:dsRed; elaA:EGFP was generated and named LiPan for liver-specific expression of DsRed RFP and exocrine pancreas-specific expression of GFP. Using the LiPan line, we first followed the dynamic development of liver from live embryos to adult and showed the formation of three distinct yet connected liver lobes during development. The LiPan line was then crossed with Tg(fli1:EGFPy1 and vascular development in the liver was traced in vivo. Liver vasculogenesis started at 55–58 hpf when ECs first surrounded hepatocytes from the liver bud surface and then invaded the liver to form sinusoids and later the vascular network. Using a novel non-invasive and label-free fluorescence correction spectroscopy, we detected blood circulation in the liver starting at ~72 hpf. To analyze the roles of ECs and blood circulation in liver development, both cloche mutants (lacking ECs and Tnnt2 morphants (no blood circulation were employed. We found that until 70 hpf liver growth and morphogenesis depended on ECs and nascent sinusoids. After 72 hpf, a functional sinusoidal network was essential for continued liver growth. An absence of blood circulation in Tnnt2 morphants caused defects in liver vasculature and small liver. Conclusion There are two phases of liver development in zebrafish, budding and growth. In the growth phase

  17. Early Weight Gain, Linear Growth, and Mid-Childhood Blood Pressure

    DEFF Research Database (Denmark)

    Perng, Wei; Rifas-Shiman, Sheryl L; Kramer, Michael S;

    2016-01-01

    In recent years, the prevalence of hypertension and prehypertension increased markedly among children and adolescents, highlighting the importance of identifying determinants of elevated blood pressure early in life. Low birth weight and rapid early childhood weight gain are associated with higher...... future blood pressure. However, few studies have examined the timing of postnatal weight gain in relation to later blood pressure, and little is known regarding the contribution of linear growth. We studied 957 participants in Project Viva, an ongoing US prebirth cohort. We examined the relations of...... gains in body mass index z-score and length/height z-score during 4 early life age intervals (birth to 6 months, 6 months to 1 year, 1 to 2 years, and 2 to 3 years) with blood pressure during mid-childhood (6-10 years) and evaluated whether these relations differed by birth size. After accounting for...

  18. EFFECT OF TURMERIC (CURCUMA LONGA SUPPLEMENTATION ON GROWTH AND BLOOD CHEMISTRY OF BROILERS

    Directory of Open Access Journals (Sweden)

    Kamdev Sethy

    2016-06-01

    Full Text Available To access the effect of turmeric (Curcuma longa supplementation on growth and blood chemistry of broiler chickens, seventy five day old straight run coloured synthetic broiler chicks were randomly divided into 3 groups (25 chicks per group. Group I served as control (without any supplementation, where as birds in groups II and III were supplemented with 0.5% and 1.0% Curcuma longa powder respectively and the trail was lasted for 7 weeks, during which weekly body weight changes were recorded. Blood samples were collected at the end of the experiment to study the blood profile of birds. The results indicated that addition of Curcuma longa powder caused significant (P0.05 effect on blood biochemical parameters of bird. The present results confirmed the beneficial effects of dietary Curcuma longa powder to improve body weight and Hb concentration of broiler chickens.

  19. Sustained Angiopoietin-2 Expression Disrupts Vessel Formation and Inhibits Glioma Growth

    Directory of Open Access Journals (Sweden)

    Ok-Hee Lee

    2006-05-01

    Full Text Available Systematic analyses of the expression of angiogenic regulators in cancer models should yield useful information for the development of novel therapies for malignant gliomas. In this study, we analyzed tumor growth, vascularization, and angiopoietin-2 (Ang2 expression during the development of U-87 MG xenografts. We found that tumoral angiogenesis in this model follows a multistage process characterized by avascular, prolific peripheral angiogenesis, and late vascular phases. On day 4, we observed an area of central necrosis, a peripheral ring of Ang2-positive glioma cells, and reactive Ang2-positive vascular structures in the tumor/brain interface. When the tumor had developed a vascular network, Ang2 was expressed only in peripheral vascular structures. Because Ang2 expression was downmodulated in the late stages of development, probably to maintain a stable tumoral vasculature, we next studied whether sustained Ang2 expression might impair vascular development and, ultimately, tumor growth. Ang2 prevented the formation of capillary-like structures and impaired angiogenesis in a chorioallantoic membrane chicken model. Finally, we tested the effect of sustained Ang2 expression on U-87 MG xenograff development. Ang2 significantly prolonged the survival of intracranial U-87 MG tumor-bearing animals. Examination of Ang2treated xenograffs revealed areas of tumor necrosis and vascular damage. We therefore conclude that deregulated Ang2 expression during gliomagenesis hindered successful angiogenesis and that therapies that sustain Ang2 expression might be effective against malignant gliomas.

  20. Beyond birth-weight: early growth and adolescent blood pressure in a Peruvian population

    Directory of Open Access Journals (Sweden)

    Robie Sterling

    2014-06-01

    Full Text Available Background. Longitudinal investigations into the origins of adult essential hypertension have found elevated blood pressure in children to accurately track into adulthood, however the direct causes of essential hypertension in adolescence and adulthood remains unclear. Methods. We revisited 152 Peruvian adolescents from a birth cohort tracked from 0 to 30 months of age, and evaluated growth via monthly anthropometric measurements between 1995 and 1998, and obtained anthropometric and blood pressure measurements 11–14 years later. We used multivariable regression models to study the effects of infantile and childhood growth trends on blood pressure and central obesity in early adolescence. Results. In regression models adjusted for interim changes in weight and height, each 0.1 SD increase in weight for length from 0 to 5 months of age, and 1 SD increase from 6 to 30 months of age, was associated with decreased adolescent systolic blood pressure by 1.3 mm Hg (95% CI −2.4 to −0.1 and 2.5 mm Hg (95% CI −4.9 to 0.0, and decreased waist circumference by 0.6 (95% CI −1.1 to 0.0 and 1.2 cm (95% CI −2.3 to −0.1, respectively. Growth in infancy and early childhood was not significantly associated with adolescent waist-to-hip ratio. Conclusions. Rapid compensatory growth in early life has been posited to increase the risk of long-term cardiovascular morbidities such that nutritional interventions may do more harm than good. However, we found increased weight growth during infancy and early childhood to be associated with decreased systolic blood pressure and central adiposity in adolescence.

  1. MR vascular fingerprinting: A new approach to compute cerebral blood volume, mean vessel radius, and oxygenation maps in the human brain.

    Science.gov (United States)

    Christen, T; Pannetier, N A; Ni, W W; Qiu, D; Moseley, M E; Schuff, N; Zaharchuk, G

    2014-04-01

    In the present study, we describe a fingerprinting approach to analyze the time evolution of the MR signal and retrieve quantitative information about the microvascular network. We used a Gradient Echo Sampling of the Free Induction Decay and Spin Echo (GESFIDE) sequence and defined a fingerprint as the ratio of signals acquired pre- and post-injection of an iron-based contrast agent. We then simulated the same experiment with an advanced numerical tool that takes a virtual voxel containing blood vessels as input, then computes microscopic magnetic fields and water diffusion effects, and eventually derives the expected MR signal evolution. The parameter inputs of the simulations (cerebral blood volume [CBV], mean vessel radius [R], and blood oxygen saturation [SO2]) were varied to obtain a dictionary of all possible signal evolutions. The best fit between the observed fingerprint and the dictionary was then determined by using least square minimization. This approach was evaluated in 5 normal subjects and the results were compared to those obtained by using more conventional MR methods, steady-state contrast imaging for CBV and R and a global measure of oxygenation obtained from the superior sagittal sinus for SO2. The fingerprinting method enabled the creation of high-resolution parametric maps of the microvascular network showing expected contrast and fine details. Numerical values in gray matter (CBV=3.1±0.7%, R=12.6±2.4μm, SO2=59.5±4.7%) are consistent with literature reports and correlated with conventional MR approaches. SO2 values in white matter (53.0±4.0%) were slightly lower than expected. Numerous improvements can easily be made and the method should be useful to study brain pathologies. PMID:24321559

  2. Lymph flow regulates collecting lymphatic vessel maturation in vivo

    OpenAIRE

    Sweet, Daniel T.; Jiménez, Juan M.; Chang, Jeremy; Hess, Paul R.; Mericko-Ishizuka, Patricia; Fu, Jianxin; Xia, Lijun; Davies, Peter F.; Kahn, Mark L.

    2015-01-01

    Fluid shear forces have established roles in blood vascular development and function, but whether such forces similarly influence the low-flow lymphatic system is unknown. It has been difficult to test the contribution of fluid forces in vivo because mechanical or genetic perturbations that alter flow often have direct effects on vessel growth. Here, we investigated the functional role of flow in lymphatic vessel development using mice deficient for the platelet-specific receptor C-type lecti...

  3. Unusual origin and potentially hazardous course of the major blood vessels in neck – A clinically relevant rare case

    Directory of Open Access Journals (Sweden)

    Rastogi R

    2010-04-01

    Full Text Available We present a rare case of aberrant left brachiocephalic vein and brachiocephalic artery, which crosses the trachea in the neck obliquely and closely related to lower border of thyroid gland. If not noticed while performing open or percutaneous dilatational tracheostomy or other neck surgeries, trauma to these vessel and subsequent hemorrhage can occur and may be fatal. Vascular compression of the airway causing obstructive symptoms can also occur due to this anomaly. In this report the case is presented along with its clinical significance.

  4. Experimental investigation of the functional behavior of blood vessels of the pulpa dentis with a semiconductor probe

    International Nuclear Information System (INIS)

    A nuclear medicine method is presented for blood circulation in the pulpa dentis, considering biological peculiarities. The beta emitting radiopharmaceutical DF32P (diisopropyl fluorophosphate) and specially prepared beagle teeth were used. The incorporated radioactivity was 350 to 750 μCi per animal. Measurements were performed with small semiconductor detector probes with lithium-coated silicon crystals from VEB MKD Dresden. The properties of the probes are described in detail. The results permit to draw conclusions with regard to the volume of blood circulation in the pulpa dentis under physiological and experimentally induced patho-physiological conditions. (author)

  5. New findings on the three-dimensional anatomical relations between the bronchi and pulmonary blood vessels at the pulmonary hilum.

    Science.gov (United States)

    Onuki, Takamasa; Kanzaki, Masato; Kikkawa, Takuma; Isaka, Tamami; Sakamoto, Kei; Oyama, Kunihiro; Murasugi, Masahide

    2015-05-01

    During the 1940s, considerable knowledge was acquired about the anatomy of pulmonary segments, and anatomical terms were proposed and have been widely accepted. In recent years, minimally invasive and thoracoscopic segmentectomy has been performed with a versatile sublobar resection approach on patients with early peripheral lung cancer, metastatic lung tumors, and undiagnosed nodules. The three-dimensional (3D) anatomy of the bronchi and the pulmonary vessels has also been studied in individual patients. Three-dimensional models of the bronchi and pulmonary vessels were prepared using homemade software from computed tomograms (CT) of the chests of patients scheduled to undergo surgical procedures. Using these models, the authors examined the 3D positional relationships of the segmental broncho-arterial triangle (SBAT) created by three points defined by the origins and courses of the bronchi and the pulmonary arteries, which are located apart from each other at the pulmonary hilum, and the segmental pulmonary veins (SPV), which run near the SBAT. In the left and right upper lobes, many branches of the pulmonary arteries and parallel bronchi in subsegments were widely separated at the origin of the pulmonary hilum, creating a relatively large SBAT. However, as an exceptional case, an SPV passed through an SBAT in only one of 158 patients. To our knowledge, no similar findings have been documented previously. Our findings could help to determine resection surfaces for thoracoscopic segmentectomy in the future, and provide new insights into the 3D anatomy and development of the lung. PMID:25546314

  6. A Study on the Pre-and Post-irradiation Effect of Blood Vessels in the Experimentally Induced Tongue Cancer

    International Nuclear Information System (INIS)

    The author observed the changes of vasculature of pre-and post-irradiation on DMBA induced rat tongue cancer. The study was performed by using vascular corrosion resin casting, and scanning electron microscopy. The results were as follows. 1. The capillaries runned parallely and formed bundles and, sometimes, plexus. The endothelial cells were arranged regularly and small pores were observed. 2. In irradiated normal tongue the capillaries were curved slightly and formed plexus on initial day of post-irradiation. On third day the capillaries and capillary pores were dilated and the endothelial cell arrangement was irregular. The effects of irradiation were gradually increased from initial to the 3rd day, though it was decreased after 7th day. 3. The vasculature of DMBA induced tongue cancer group were very irregular, and large avascular lesions were formed according to the cancer necrosis or tumor cell nest and the vasculature was narrowed and paralleled around the avascular lesion by compression of cancer cell nest. The vascular wall was roughened and dilated, forming club shaped or varix. 4. The vessels were curved and formed reticular network in irradiated DMBA induced tongue carinoma group. The free end of newly formed capillaries had regular width, and also irregular club shaped or aneurysmal dilation were observed. The vascular structures were destroyed and vessels were fused in tumor necrosis lesion. The radiation effects were marked on the first and third day of irradiation and the effects were decreased after seventh day and showed capillary regeneration.

  7. Development and bioevaluation of nanofibers with blood-derived growth factors for dermal wound healing.

    Science.gov (United States)

    Bertoncelj, Valentina; Pelipenko, Jan; Kristl, Julijana; Jeras, Matjaž; Cukjati, Marko; Kocbek, Petra

    2014-09-01

    The aim of our work was to produce a modern nanomaterial with incorporated blood-derived growth factors, produced by electrospinning, applicable in treatment of chronic wounds. Platelet-rich plasma was chosen as a natural source of growth factors. Results showed that platelet-rich plasma stimulates keratinocyte and fibroblast cell growth in vitro. Its optimal concentration in growth medium was 2% (v/v) for both types of skin cells, while higher concentrations caused alterations in cell morphology, with reduced cell mobility and proliferation. In the next step hydrophilic nanofibers loaded with platelet-rich plasma were produced from chitosan and poly(ethylene oxide), using electrospinning. The morphology of nanofibers was stable in aqueous conditions for 72 h. It was shown that electrospinning does not adversely affect the biological activity of platelet-rich plasma. The effects of nanofibers with incorporated platelet-rich plasma on cell proliferation, survival, morphology and mobility were examined. Nanofibers limited cell mobility, changed morphology and stimulated cell proliferation. Despite of the small amount of blood-derived growth factors introduced in cell culture via platelet-rich plasma-loaded nanofibers, such nanofibrillar support significantly induced cell proliferation, indicating synergistic effect of nanotopography and incorporated growth factors. The overall results confirm favorable in vitro properties of produced nanofibers, indicating their high potential as a nanomaterial suitable for delivery of platelet-rich plasma in wound healing applications. PMID:24931341

  8. Methotrexate reduces hippocampal blood vessel density and activates microglia in rats but does not elevate central cytokine release

    NARCIS (Netherlands)

    Seigers, Riejanne; Timmermans, Jessica; van der Horn, Hans J.; de Vries, Erik F. J.; Dierckx, Rudi A.; Visser, Lydia; Schagen, Sanne B.; van Dam, Frits S. A. M.; Koolhaas, Jaap M.; Buwalda, Bauke

    2010-01-01

    Methotrexate is a cytostatic drug applied in adjuvant chemotherapy and associated with cognitive impairment in part of the cancer patients. In this paper we studied in rats whether a reduction in blood supply to the brain or neuroinflammation are possible mediators of this cognitive dysfunctionality

  9. Growth and survival of Serratia marcescens under aerobic and anaerobic conditions in the presence of materials from blood bags.

    OpenAIRE

    Szewzyk, U; Szewzyk, R; Stenström, T A

    1993-01-01

    Several patients receiving blood transfusions during the summer of 1991 developed bacteremia after the transfusion. In all cases, the infection was caused by Serratia marcescens. The same strain of Serratia marcescens was isolated from the patients and from the outer surface of unfilled blood bags. The transport containers for the blood bags were made anoxic by using a catalyst in order to prevent microbial growth. The survival and growth of S. marcescens K202, which was isolated from the blo...

  10. Relation of fingerprints and shape of the palm to fetal growth and adult blood pressure.

    OpenAIRE

    Godfrey, K M; Barker, D J; Peace, J; Cloke, J.; Osmond, C

    1993-01-01

    OBJECTIVE--To examine how finger and palm prints are related to fetal growth and adult blood pressure. DESIGN--Follow up study of babies born around 50 years ago whose birth weight, placental weight, head circumference, and length at birth were recorded. SETTING--Preston, Lancashire. SUBJECTS--139 men and women born in Sharoe Green Hospital in Preston during 1935-43 and still living in Lancashire. MAIN OUTCOME MEASURES--Finger and palm prints and current blood pressure. RESULTS--People who we...

  11. Vessel Operating Units (Vessels)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains data for vessels that are greater than five net tons and have a current US Coast Guard documentation number. Beginning in1979, the NMFS...

  12. Blood oxygenation level-dependent magnetic resonance imaging during carbogen breathing: differentiation between prostate cancer and benign prostate hyperplasia and correlation with vessel maturity

    Science.gov (United States)

    Di, Ningning; Mao, Ning; Cheng, Wenna; Pang, Haopeng; Ren, Yan; Wang, Ning; Liu, Xinjiang; Wang, Bin

    2016-01-01

    Objective The aim of this study was to investigate whether the blood oxygenation level-dependent (BOLD) contrast magnetic resonance imaging (MRI) can evaluate tumor maturity and preoperatively differentiate prostate cancer (PCa) from benign prostate hyperplasia (BPH). Patients and methods BOLD MRI based on transverse relaxation time*-weighted echo planar imaging was performed to assess PCa (19) and BPH (22) responses to carbogen (95% O2 and 5% CO2). The average signal values of PCa and BPH before and after carbogen breathing and the relative increased signal values were computed, respectively. The endothelial-cell marker, CD31, and the pericyte marker, α-smooth muscle actin (mature vessels), were detected with immunofluorescence, and were assessed by microvessel density (MVD) and microvessel pericyte density (MPD). The microvessel pericyte coverage index (MPI) was used to evaluate the degree of vascular maturity. The changed signal from BOLD MRI was correlated with MVD, MPD, and MPI. Results After inhaling carbogen, both PCa and BPH showed an increased signal, but a lower slope was found in PCa than that in BPH (PMPI than BPH. The increased signal intensity was positively correlated with MPI in PCa and that in BPH (r=0.616, P=0.011; r=0.658, P=0.002); however, there was no correlation between the increased signal intensity and MPD or MVD in PCa than that in BPH (P>0.05). Conclusion Our results confirmed that the increased signal values induced by BOLD MRI well differentiated PCa from BPH and had a positive correlation with vessel maturity in both of them. BOLD MRI can be utilized as a surrogate marker for the noninvasive assessment of the degree of vessel maturity. PMID:27462169

  13. High-Yield Method for Isolation and Culture of Endothelial Cells from Rat Coronary Blood Vessels Suitable for Analysis of Intracellular Calcium and Nitric Oxide Biosynthetic Pathways

    Science.gov (United States)

    Nistri, Silvia; Mazzetti, Luca; Failli, Paola

    2002-01-01

    We describe here a method for isolating endothelial cells from rat heart blood vessels by means of coronary microperfusion with collagenase. This methods makes it possible to obtain high amounts of endothelial cells in culture which retain the functional properties of their in vivo counterparts, including the ability to uptake fluorescently-labeled acetylated low-density lipoproteins and to respond to vasoactive agents by modulating intracellular calcium and by upregulating intrinsic nitric oxide generation. The main advantages of our technique are: (i) good reproducibility, (ii) accurate sterility that can be maintained throughout the isolation procedure and (iii) high yield of pure endothelial cells, mainly due to microperfusion and temperature-controlled incubation with collagenase which allow an optimal distribution of this enzyme within the coronary vascular bed. PMID:12734571

  14. Computer simulation of MHD blood conveying gold nanoparticles as a third grade non-Newtonian nanofluid in a hollow porous vessel.

    Science.gov (United States)

    Hatami, M; Hatami, J; Ganji, D D

    2014-02-01

    In this paper, heat transfer and flow analysis for a non-Newtonian third grade nanofluid flow in porous medium of a hollow vessel in presence of magnetic field are simulated analytically and numerically. Blood is considered as the base third grade non-Newtonian fluid and gold (Au) as nanoparticles are added to it. The viscosity of nanofluid is considered a function of temperature as Vogel's model. Least Square Method (LSM), Galerkin method (GM) and fourth-order Runge-Kutta numerical method (NUM) are used to solve the present problem. The influences of the some physical parameters such as Brownian motion and thermophoresis parameters on non-dimensional velocity and temperature profiles are considered. The results show that increasing the thermophoresis parameter (N(t)) caused an increase in temperature values in whole domain and an increase in nanoparticles concentration just near the inner wall of vessel. Furthermore by increasing the MHD parameter, velocity profiles decreased due to magnetic field effect. PMID:24286727

  15. On the bifurcation of blood vessels--Wilhelm Roux's doctoral thesis (Jena 1878)--a seminal work for biophysical modelling in developmental biology.

    Science.gov (United States)

    Kurz, H; Sandau, K; Christ, B

    1997-02-01

    Wilhelm Roux's doctoral thesis described the relationship between the angle and diameter of bifurcating blood vessels. We have re-read this work in the light of biophysics and developmental biology and found two remarkable aspects hidden among a multitude of observations, rules and exceptions to these rules. First, the author identified the major determinants involved in vascular development; genetics, cybernetics, and mechanics; moreover, he knew that he could not deal with the genetic and regulatory aspects, and could hardly treat the mechanical part adequately. Second, he was deeply convinced that the laws of physics determine the design of organisms, and that a necessity for optimality was inherent in development. We combined the analysis of diameter relationships with the requirement for optimality in a stochastic biophysical model, and concluded that a constant wall-stress condition could define a minimum wall-tissue optimum during arterial development. Hence, almost 120 years after Wilhelm Roux's pioneering work, our model indicates one possible way in which physical laws have determined the evolution of regulatory and structural properties in vessel wall development. PMID:9059737

  16. Functional and pharmacological consequences of the distribution of voltage-gated calcium channels in the renal blood vessels

    DEFF Research Database (Denmark)

    Hansen, P B L

    2013-01-01

    usually associated with vascular contractility. However, the L-, T- and P-/Q-types of calcium channels are present in the renal vasculature and are differentially involved in controlling vascular contractility, thereby contributing to regulation of kidney function and blood pressure. In the preglomerular...... to preferential efferent vasodilation, reduction of glomerular pressure and proteinuria. Therefore, renovascular T-type channels might provide novel therapeutic targets, and may have superior renoprotective effects compared to conventional calcium blockers....

  17. Blood Pressure Regulation VIII: Resistance Vessel Tone and Implications for a Pro-Atherogenic Conduit Artery Endothelial Cell Phenotype

    OpenAIRE

    Padilla, Jaume; Jenkins, Nathan T.; Laughlin, M. Harold; Fadel, Paul J.

    2013-01-01

    Dysfunction of the endothelium is proposed as the primary initiator of atherosclerotic peripheral artery disease, which occurs mainly in medium to large-sized conduit arteries of the lower extremities (e.g., iliac, femoral, popliteal arteries). In this review article, we propose the novel concept that conduit artery endothelial cell phenotype is determined, in part, by microvascular tone in skeletal muscle resistance arteries through both changes in arterial blood pressure as well as upstream...

  18. Flow Measurements in a Blood-Perfused Collagen Vessel Using X-Ray Micro-Particle Image Velocimetry.

    OpenAIRE

    Antoine, Elizabeth; Buchanan, Cara; Fezzaa, Kamel; Lee, Wah-Keat; Rylander, Nichole; Vlachos, Pavlos

    2013-01-01

    Blood-perfused tissue models are joining the emerging field of tumor engineering because they provide new avenues for modulation of the tumor microenvironment and preclinical evaluation of the therapeutic potential of new treatments. The characterization of fluid flow parameters in such in-vitro perfused tissue models is a critical step towards better understanding and manipulating the tumor microenvironment. However, traditional optical flow measurement methods are inapplicable because of th...

  19. Correlation between expressions of hypoxia -inducible factor (HIF-1α, blood vessels density, cell proliferation, and apoptosis intensity in canine fibromas and fibrosarcomas

    Directory of Open Access Journals (Sweden)

    Madej Janusz A.

    2014-03-01

    Full Text Available The study aimed to demonstrate the expression of hypoxia-inducible factor (HIF-1α in soft tissue mesenchymal tumours (fibroma and fibrosarcoma in dogs. An attempt was made to correlate the obtained results with density of blood vessels (expression of von Willebrand Factor, vWF, expression of Ki-67 proliferation antigen, and with intensity of apoptosis in studied tumours. The study was performed on paraffin sections of 15 fibromas and 40 fibrosarcomas sampled from 55 female dogs aged 6 to 16 years. Immunohistochemical staining against HIF-1α, vWF, and Ki-67 was performed. Apoptosis was detected with the use of TUNEL reaction. A significantly higher HIF-1α expression was noted in fibrosarcomas in comparison to fibromas (P < 0.0001. HIF-1α expression in fibromas manifested strong positive correlation with tumour vascularity (r = 0.67, P = 0.007. Moreover, HIF-1α expression in fibrosarcomas manifested a moderate positive correlation with tumour malignancy grade (r = 0.44, P = 0.004, tumour vascularity (r = 0.52, P < 0.001, Ki-67 antigen expression (r = 0.42; P = 0.007, and TUNELpositive cells (r = 0.37, P = 0.017. Expression of HIF-1α was detected in 86.7% of fibroma type tumours and in 100% of fibrosarcomas. In all studied tumours expression of HIF-1α manifested positive correlation with the density of blood vessels, and in fibrosarcomas it correlated also with malignancy grade, intensity of Ki-67 expression, and with intensity of apoptosis in tumour cells.

  20. Flow measurements in a blood-perfused collagen vessel using x-ray micro-particle image velocimetry.

    Directory of Open Access Journals (Sweden)

    Elizabeth Antoine

    Full Text Available Blood-perfused tissue models are joining the emerging field of tumor engineering because they provide new avenues for modulation of the tumor microenvironment and preclinical evaluation of the therapeutic potential of new treatments. The characterization of fluid flow parameters in such in-vitro perfused tissue models is a critical step towards better understanding and manipulating the tumor microenvironment. However, traditional optical flow measurement methods are inapplicable because of the opacity of blood and the thickness of the tissue sample. In order to overcome the limitations of optical method we demonstrate the feasibility of using phase-contrast x-ray imaging to perform microscale particle image velocimetry (PIV measurements of flow in blood perfused hydrated tissue-representative microvessels. However, phase contrast x-ray images significantly depart from the traditional PIV image paradigm, as they have high intensity background, very low signal-to-noise ratio, and volume integration effects. Hence, in order to achieve accurate measurements special attention must be paid to the image processing and PIV cross-correlation methodologies. Therefore we develop and demonstrate a methodology that incorporates image preprocessing as well as advanced PIV cross-correlation methods to result in measured velocities within experimental uncertainty.

  1. Multiple sites of action of (+)-3-(3-hydroxyphenyl)-N-(1-propyl)piperidine ((+)-3PPP) in blood vessels.

    Science.gov (United States)

    Massamiri, T; Duckles, S P

    1990-11-13

    Functional effects of the sigma ligand, (+)-3-(3-hydroxyphenyl)-N-(1-propyl)piperidine ((+)-3PPP), were explored in perfused rat tail and rabbit ear arteries in vitro. In the rat tail artery (+)-3PPP inhibited contractile responses to adrenergic nerve stimulation, an effect which was reversed to potentiation by the dopamine D2 receptor antagonist sulpiride. In the rabbit ear artery, however, (+)-3PPP potentiated contractile responses to nerve stimulation, an effect which was unchanged by sulpiride. In the rat tail artery, blockade of norepinephrine uptake by cocaine and deoxycorticosterone in the presence of sulpiride revealed two additional actions of (+)-3PPP. First, an inhibitory action on the monoamine uptake site was confirmed by direct measurement of [3H]norepinephrine accumulation. Second, at higher concentrations, an action to inhibit contractile responses to adrenergic nerve stimulation was manifested at a still unidentified site. These studies demonstrate that the observed functional effect of (+)-3PPP results from its combined actions on three individual sites with the net effect dependent on the relative densities of these different receptor sites in each type of vessel. PMID:2272368

  2. Anatomy of abdominal blood vessels for imaging diagnosis and IVR [4] liver, gall bladder, pancreas and spleen. (3) Liver-1

    International Nuclear Information System (INIS)

    This paper describes the anatomical outline of liver vasculature and related matters including vascular architecture revealed by imaging. The related matters contain the embryonic development of the organ and its vasculature, channel to mesentery and ducts/vessels (shown also by images of the digital subtraction angiography, dynamic CT and CT with multi projection volume reconstruction), morphology of the liver involving its modification and surrounding structures, and functional segments like Healey/Schroys', Couinaud's and Ryu/Shos'. Japanese classification of segmental and lobular vasculature is essentially based on the above Couinaud's concept. According to 3D CT maximum intensity projection (MIP) images, the origin of intrahepatic portal vein is distinguished in 3 types (normal branching 71-90% and others 4-17%). The vein revealed by multi detector (MD) CT often exhibits various modifications. Hepatic veins are important at liver transplantation and also have been shown to exhibit many variations by CTMIP. Hepatic arteries are similar. Exact anatomy of liver has not been fully elucidated hitherto because of difficulty to deal with multiple cases but MDCT is promising for the problem, and for which, to understand the concept of segments and to identify their regional vasculature are thought meaningful. (K.T.)

  3. Variable tumour blood flow influences tumour growth and hypoxia in rodents and humans

    International Nuclear Information System (INIS)

    We are studying the causes and implications of variable tumour blood flow in clinical and xenografted tumours using immunohistochemical techniques with flow cytometry and image analysis. Both established tumour xenograft systems and biopsies of in-situ cervical cancer after pimonidazole administration have been evaluated. In the laboratory, enzymatic reduction of part of the biopsy to a single cell suspension has been followed by pulse labelling with iododeoxyuridine, then fixation for flow analysis of DNA content. The remaining material, like that from xenografts infused with Hoechst 33342 to indicate blood flow, has been analyzed by image cytometry after staining with proliferation (IUdR, PCNA or Ki-67/MIB1) or structural (cytokeratin, CD31, CD104, etc.) markers. The variability of tumour blood flow that can be easily documented in xenografts leads to discontinuities in proliferation and hypoxia that appear to be duplicated in the clinic. Interestingly, more than half of the tumours with substantial pimonidazole labelling showed hypoxic cells capable of incorporating IUdR in vitro, thus suggesting transient hypoxia in in-situ human tumours. Other evidence also suggests that tumour blood flow is non-constant in patients. Two preliminary conclusions are emerging: 1) non-constant blood flow that provides an additional restriction on tumour growth rate in the pre-treatment situation may lead to rapidly accelerated repopulation following the initiation of chemo- or radiotherapy, and 2) a significant fraction of human cervix cancers may express both 'acute' and 'chronic' hypoxia. Both observations are consistent with non-constant blood flow leading to dynamic time-dependent changes in hypoxia and proliferation patterns. With our xenograft systems, we are now undertaking 3-D assessments of tumour vasculature and its function that are expected to provide an improved understanding of the tumour-level factors that result in non-constant tumour blood flow

  4. Using non-linear analogue of Nyquist diagrams for analysis of the equation describing the hemodynamics in blood vessels near pathologies

    Science.gov (United States)

    Cherevko, A. A.; Bord, E. E.; Khe, A. K.; Panarin, V. A.; Orlov, K. J.; Chupakhin, A. P.

    2016-06-01

    This article considers method of describing the behaviour of hemodynamic parameters near vascular pathologies. We study the influence of arterial aneurysms and arteriovenous malformations on the vascular system. The proposed method involves using generalized model of Van der Pol-Duffing to find out the characteristic behaviour of blood flow parameters. These parameters are blood velocity and pressure in the vessel. The velocity and pressure are obtained during the neurosurgery measurements. It is noted that substituting velocity on the right side of the equation gives good pressure approximation. Thus, the model reproduces clinical data well enough. In regard to the right side of the equation, it means external impact on the system. The harmonic functions with various frequencies and amplitudes are substituted on the right side of the equation to investigate its properties. Besides, variation of the right side parameters provides additional information about pressure. Non-linear analogue of Nyquist diagrams is used to find out how the properties of solution depend on the parameter values. We have analysed 60 cases with aneurysms and 14 cases with arteriovenous malformations. It is shown that the diagrams are divided into classes. Also, the classes are replaced by another one in the definite order with increasing of the right side amplitude.

  5. Low blood glucose levels and other complications during growth hormone supplementation in sepsis

    Directory of Open Access Journals (Sweden)

    Faintuch Joel

    1999-01-01

    Full Text Available Blood glucose levels in the high normal range or even moderate hyperglycemia is the expected profile in septic postoperative patients receiving high-calorie enteral alimentation. The addition of growth hormone as an anabolic agent should additionally reinforce this tendency. In a cancer patient undergoing partial gastrectomy with lymphadenectomy and suffering from postoperative subphrenic abscess and prolonged sepsis, tube feeding (38.3 kcal/kg/day and growth hormone (0.17 IU/kg/day were simultaneously administered for 25 days. Blood glucose levels were in the lower limits of the normal range before growth hormone introduction, and continued with a similar tendency during most of the therapeutic period. Two additional complications, namely heart arrest and peripheral edema, were documented during the same period. It is concluded that sepsis was the most likely mechanism for low glucose values, and that high-calorie enteral diet and growth hormone supplementation did not prevent that result. It is uncertain whether heart arrest was due to the drug, but its association with peripheral edema is well documented in clinical series.

  6. Perinatal outcome of growth restricted fetus with absent end diastolic umbilical blood flow: Case report

    Directory of Open Access Journals (Sweden)

    Tasić Marija

    2010-01-01

    Full Text Available Introduction. Absent or reversed end-diastolic blood flow in the umbilical artery is usually associated with poor perinatal outcome and high perinatal mortality rate. Case report. We present the case of a pregnant woman with absent end-diastolic blood flow in the umbilical artery in the 27th week of pregnancy with initial restriction of fetal growth. All though it was more and more obvious that the fetal growth was hindered, the Doppler, cardiotocographic and biophysical parameters did not get any worse as the pregnancy developed. The full fetal maturation was reached after the intense monitoring of the fetal condition and the pregnancy was terminated in the 37lh week by elective Cesarean section. Conclusion. The basic purpose of prenatal fetal monitoring in the situation of hindered fetal growth with chronic hypoxia is to predict the phase of decompensation and to terminate pregnancy before it is developed. The major problem is in great individual variations at the moment of development of decompensation phase, so the major obstetric aim in the monitoring of the fetus hindered in growth is to determine the optimal time and way of delivery.

  7. Chronic Blockade of the Androgen Receptor Abolishes Age-Dependent Increases in Blood Pressure in Female Growth-Restricted Rats.

    Science.gov (United States)

    Dasinger, John Henry; Intapad, Suttira; Rudsenske, Benjamin R; Davis, Gwendolyn K; Newsome, Ashley D; Alexander, Barbara T

    2016-06-01

    Intrauterine growth restriction induced via placental insufficiency programs a significant increase in blood pressure at 12 months of age in female growth-restricted rats that is associated with early cessation of estrous cyclicity, indicative of premature reproductive senescence. In addition, female growth-restricted rats at 12 months of age exhibit a significant increase in circulating testosterone with no change in circulating estradiol. Testosterone is positively associated with blood pressure after menopause in women. Thus, we tested the hypothesis that androgen receptor blockade would abolish the significant increase in blood pressure that develops with age in female growth-restricted rats. Mean arterial pressure was measured in animals pretreated with and without the androgen receptor antagonist, flutamide (8 mg/kg/day, SC for 2 weeks). Flutamide abolished the significant increase in blood pressure in growth-restricted rats relative to control at 12 months of age. To examine the mechanism(s) by which androgens contribute to increased blood pressure in growth-restricted rats, blood pressure was assessed in rats untreated or treated with enalapril (250 mg/L for 2 weeks). Enalapril eliminated the increase in blood pressure in growth-restricted relative to vehicle- and flutamide-treated controls. Furthermore, the increase in medullary angiotensin type 1 receptor mRNA expression was abolished in flutamide-treated growth-restricted relative to untreated counterparts and controls; cortical angiotensin-converting enzyme mRNA expression was reduced in flutamide-treated growth-restricted versus untreated counterparts. Thus, these data indicate that androgens, via activation of the renin-angiotensin system, are important mediators of increased blood pressure that develops by 12 months of age in female growth-restricted rats. PMID:27113045

  8. Blood donation before surgery

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000367.htm Blood donation before surgery To use the sharing features ... vessels. Several sources of blood are described here. Blood From the Public (Volunteer Blood Donation) The most ...

  9. High blood pressure

    Science.gov (United States)

    ... you are at risk for: Bleeding from the aorta, the large blood vessel that supplies blood to ... tests Blood pressure check Blood pressure References American Diabetes Association. Standards of medical care in diabetes-2015 ...

  10. Cyclic Crack Growth Testing of an A.O. Smith Multilayer Pressure Vessel with Modal Acoustic Emission Monitoring and Data Assessment

    Science.gov (United States)

    Ziola, Steven M.

    2014-01-01

    Digital Wave Corp. (DWC) was retained by Jacobs ATOM at NASA Ames Research Center to perform cyclic pressure crack growth sensitivity testing on a multilayer pressure vessel instrumented with DWC's Modal Acoustic Emission (MAE) system, with captured wave analysis to be performed using DWCs WaveExplorerTM software, which has been used at Ames since 2001. The objectives were to document the ability to detect and characterize a known growing crack in such a vessel using only MAE, to establish the sensitivity of the equipment vs. crack size and / or relevance in a realistic field environment, and to obtain fracture toughness materials properties in follow up testing to enable accurate crack growth analysis. This report contains the results of the testing.

  11. A computational model of the fetal circulation to quantify blood redistribution in intrauterine growth restriction.

    Directory of Open Access Journals (Sweden)

    Patricia Garcia-Canadilla

    2014-06-01

    Full Text Available Intrauterine growth restriction (IUGR due to placental insufficiency is associated with blood flow redistribution in order to maintain delivery of oxygenated blood to the brain. Given that, in the fetus the aortic isthmus (AoI is a key arterial connection between the cerebral and placental circulations, quantifying AoI blood flow has been proposed to assess this brain sparing effect in clinical practice. While numerous clinical studies have studied this parameter, fundamental understanding of its determinant factors and its quantitative relation with other aspects of haemodynamic remodeling has been limited. Computational models of the cardiovascular circulation have been proposed for exactly this purpose since they allow both for studying the contributions from isolated parameters as well as estimating properties that cannot be directly assessed from clinical measurements. Therefore, a computational model of the fetal circulation was developed, including the key elements related to fetal blood redistribution and using measured cardiac outflow profiles to allow personalization. The model was first calibrated using patient-specific Doppler data from a healthy fetus. Next, in order to understand the contributions of the main parameters determining blood redistribution, AoI and middle cerebral artery (MCA flow changes were studied by variation of cerebral and peripheral-placental resistances. Finally, to study how this affects an individual fetus, the model was fitted to three IUGR cases with different degrees of severity. In conclusion, the proposed computational model provides a good approximation to assess blood flow changes in the fetal circulation. The results support that while MCA flow is mainly determined by a fall in brain resistance, the AoI is influenced by a balance between increased peripheral-placental and decreased cerebral resistances. Personalizing the model allows for quantifying the balance between cerebral and peripheral

  12. The changes of oxygen extraction fraction and cerebral blood flow of brain parenchyma in patients with unilateral cerebral vessel stenosis: initial experience of the quantitative measurements

    International Nuclear Information System (INIS)

    Objective: Using gradient-echo sampling of spin-echo (GESSE) sequence to study the change of oxygen extraction fraction (OEF) in patients with unilateral cerebral vessel stenosis and the relationship between OEF and cerebral blood flow (CBF). Methods: Eight normal volunteers and 16 patients with unilateral cerebral vessel stenosis were enrolled in this study. Written informed consents were obtained from all subjects. Routine MRI, GESSE and arterial spin labeling (ASL) sequences were performed for all patients. Raw data from GESSE and VE-ASL sequences were transferred to PC to conduct postprocessing. To obtain quantitative OEF and CBF of the brain parenchyma, 6 ROIs were placed respectively in the anterior, middle and posterior part of both hemispheres. The relative CBF (rCBF) was defined as the ratio of CBF of ischemic hemisphere to that of contralateral hemisphere. T test was used for statistics. Results: The mean value and normal range of OEF in the volunteers were 0.318±0.023 and 0.272-0.364, respectively. In the 16 patients with unilateral cerebral vessel stenosis, 8 patients had ROIs with greater OEF iri unilateral hemisphere than those in contralateral hemisphere. These cases presented multiple intracranial main arterial stenoses in digital subtraction angiography (DSA) or MR angiography (MRA) examination. The other 8 patients had normal OEF in all ROIs. And they only had single arterial stenosis in DSA or MRA. Set rCBF = 0.50 as a dividing point, the mean OEF value was 0.397±0.010 in the patients with rCBF < 0.50. In the patients with rCBF ≥ 0.5, the mean OEF value was 0.325± 0.028. The difference between the two groups was statistically significant (t=-8.840, P=0.000). Conclusion: Patients with chronic cerebral ischemia may present with various hemodynamic impairment. The more CBF decreases, the more OEF increases. Those with increased OEF tended to have more than one lesion in the major intracranial arteries. (authors)

  13. Blood vessels in subcaruncular and intercaruncular bovine endometriun possess oxytocin receptors (ORT) and express otr mRNA during pregnancy

    DEFF Research Database (Denmark)

    Fuchs, Anna-Ritta; Balvers, Marga; Ivell, Richard;

    2002-01-01

    ) were then cut and mounted on Superfrost (fast+) coated slides for in situ hybridization. Tissues for immunohistochemistry were fixed in Bouin's solution, embedded in paraffin and immunoreactive (ir) OTR was visualized using the APAAP-Dualsystem procedure. The monoclonal antibody was developed against...... a peptide from the aminoterminal extracellular region of the human OTR. The antisense probes for in situ hybridization were derived by in vitro transcription of the plasmid used for cDNA primary library screening and were labeled with digoxigenin-UTP. The sections were prepared using standard procedures...... thereafter. On days 180, 218, 220 only a few large maternal veins were stained and thereafter no ir OTR nor OTR mRNA was observed. During the initial stages of placentation the maternal connective tissue was positive for ir OTR being strongest in the caruncular areas where the rapid growth of vasculature...

  14. Biochemical assessment of growth factors and circulation of blood components contained in the different fractions obtained by centrifugation of venous blood.

    Science.gov (United States)

    Corigiano, M; Ciobanu, G; Baldoni, E; Pompa, G

    2014-01-01

    The aim of this study was to evaluate a biochemical marker with different elements of a normal blood serum and centrifuged blood serum after a different rotation system. For this technique, we used five fractions of a blood Concentrated Growth Factors system (bCGF) and a particular device for the different rotation program. Blood samples were collected from 10 volunteers aged between 35 and 55 in the Operative Unit of the “Sapienza” University of Rome with only a fraction of different biochemical elements. Through an individual blood phase separator tube of venous blood, active factions of serum and 4 fractions of red buffy coat were taken. The biochemical markers with 14 elements were examined at times: P1-11 minutes, P2-12minutes, P3-15 minutes. Exclusively biological materials which are normally applied in the regeneration techniques for different defects and lesions were used with this technique. After specific rotation programs, a different result was obtained for each cycle: P1, P2, P3. In test tubes obtained by separated blood, we observed a higher concentration of proteins, ions, and other antigens compared to normal blood plasma. Examining the biochemical results of different elements, we observed an increase (P≤0,01). Since each person’s DNA is different, we could not have the same results in 5 fractions of blood concentration, we did, however, find a good increase in only a fraction of proteins, immunoglobulin and different ions. We obtained five fractions after centrifugation, and we had an increase in different biochemical elements compared to normal blood (P≤0,01) which is significant at different times. These biochemical elements were stimulated by different growth factors, which are used by the immune system, and they induced the formation of hard and soft tissues and good regeneration. PMID:25001662

  15. Localized Dose Enhancement to Tumor Blood Vessel Endothelial Cells via Megavoltage X-rays and Targeted Gold Nanoparticles: New Potential for External Beam Radiotherapy

    International Nuclear Information System (INIS)

    Purpose: Tumor endothelial cell damage during radiation therapy may contribute significantly to tumor eradication and treatment efficacy. Gold nanoparticles (AuNPs) delivered preferentially to the walls of tumor blood vessels produce low-energy, short-range photoelectrons during external beam radiotherapy, boosting dose to the tumor microvasculature. In this study dosimetry at the single-cell level is used to estimate the anticipated AuNP-mediated dose enhancement to tumor endothelial cells during 6-MV X-ray irradiation. Methods and Materials: Endothelial cells are modeled as thin slabs with 100-nm-diameter AuNPs attached within the blood vessel. The number of photoelectrons emitted per AuNP per gray of X-rays is computed at multiple points along the external beam central axis by use of a Monte Carlo-generated energy fluence spectrum. The energy deposited from AuNP emissions to the endothelium is calculated based on an analytic method incorporating the energy-loss formula of Cole. The endothelial dose enhancement factor (EDEF) is the ratio of the overall (externally plus internally generated) dose to endothelial cells in the presence of AuNPs to the dose without AuNPs (from the external beam only). Results: At 20-cm depth, the EDEF is 1.7 (70% dose increase) for an intravascular AuNP concentration of 30 mg/g. Most of this dose enhancement arises from the low-energy (approximately 100 keV) portion of the linear accelerator X-ray spectrum. Furthermore, for AuNP concentrations ranging from 7 to 140 mg/g, EDEF values of 1.2 to 4.4 (20-340% dose increase) are calculated. Conclusions: In contrast to calculations assuming that AuNPs distributed homogeneously throughout the target volume (macrodosimetry), our cellular microdosimetry calculations predict a major dose enhancement to tumor microvasculature from conventional linear accelerator X-rays. This effect may enable the delivery of ablative therapeutic doses to these sensitive microstructures while maintaining

  16. Phantom with Pulsatile Arteries to Investigate the Influence of Blood Vessel Depth on Pulse Oximeter Signal Strength

    Directory of Open Access Journals (Sweden)

    Hunor Santha

    2012-01-01

    Full Text Available This paper describes a three-layer head phantom with artificial pulsating arteries at five different depths (1.2 mm, 3.7 mm, 6.8 mm, 9.6 mm and 11.8 mm. The structure enables formation of spatially and temporally varying tissue properties similar to those of living tissues. In our experiment, pressure pulses were generated in the arteries by an electronically controlled pump. The physical and optical parameters of the layers and the liquid in the artificial arteries were similar to those of real tissues and blood. The amplitude of the pulsating component of the light returning from the phantom tissues was measured at each artery depth mentioned above. The build-up of the in-house-developed pulse oximeter used for performing the measurements and the physical layout of the measuring head are described. The radiant flux generated by the LED on the measuring head was measured to be 1.8 mW at 910 nm. The backscattered radiant flux was measured, and found to be 0.46 nW (0.26 ppm, 0.55 nW (0.31 ppm, and 0.18 nW (0.10 ppm for the 1.2 mm, 3.7 mm and 6.8 mm arteries, respectively. In the case of the 9.6 mm and 11.8 mm arteries, useful measurement data were not obtained owing to weak signals. We simulated the phantom with the arteries at the above-mentioned five depths and at two additional ones (2.5 mm and 5.3 mm in depth using the Monte Carlo method. The measurement results were verified by the simulation results. We concluded that in case of 11 mm source-detector separation the arteries at a depth of about 2.5 mm generate the strongest pulse oximeter signal level in a tissue system comprising three layers of thicknesses: 1.5 mm (skin, 5.0 mm (skull, and > 50 mm (brain.

  17. Effects of Onion Extracts on Growth Performance, Carcass Characteristics and Blood Profiles of White Mini Broilers

    OpenAIRE

    An, B. K.; Kim, J.Y.; Oh, S T; Kang, C. W.; Cho, S.; Kim, S. K.

    2015-01-01

    This experiment was carried out to investigate effects of onion extract on growth performance, meat quality and blood profiles of White mini broilers. Total of 600 one-d-old male White mini broiler chicks were divided into four groups and fed control diets (non-medicated commercial diet or antibiotics medicated) or experimental diets (non-medicated diets containing 0.3% or 0.5% onion extract) for 5 wks. The final body weight (BW) and weight gain of the group fed non-medicated control diet wer...

  18. Specific corrosion product on interior surface of a bronze wine vessel with loop-handle and its growth mechanism, Shang Dynasty, China

    International Nuclear Information System (INIS)

    In this paper, a kind of specific stalactitic product was found on the interior surface of a covered bronze wine vessel with loop-handle (Chinese name is you), which was fabricated in Shang Dynasty (1700 B.C.–1100 B.C.) and now is collected in Xiaogan Museum, Hubei province of China. The microstructures of the product were characterized systematically by using optical microscopy, scanning electron microscope, transmission electron microscope, X-ray diffraction, and Raman microscopy. The experimental results revealed that the product belonged to a kind of malachite with high purity and high crystallinity. The growth of the product was considered to be a possible reason that the vessel was overly airtight within a museum display cabinet besides a lid of the vessel, which made the excess of H2O and CO2 gas concentrations inside the vessel during long-term storage. This corrosion product is very harmful to bronze cultural relics, because of a large amount of copper consumption from the matrix which will reduce its life. The growth mechanism of the specific stalactitic product and the suggestions for preservation of the similar bronze relics in museum were proposed. - Highlights: ► The stalactitic product was the high purity and good crystallinity malachite. ► Its growth was related to the excess of H2O and CO2 gas concentrations in museum. ► It is harmful to the bronzes, because copper will be consumed from the matrix. ► The suggestions for preservation of the similar bronzes in museum were proposed.

  19. Specific corrosion product on interior surface of a bronze wine vessel with loop-handle and its growth mechanism, Shang Dynasty, China

    Energy Technology Data Exchange (ETDEWEB)

    Li Yang; Bao Zhirong; Wu Taotao [School of Physics and Technology, Center for Electron Microscopy and MOE Key Laboratory of Artificial Micro- and Nano-structures, Wuhan University, Wuhan 430072 (China); Jiang, Junchun [Xiaogan Museum, Xiaogan 432000 (China); Chen Guantao [Center for Archaeometry, Wuhan University, Wuhan 430072 (China); Pan Chunxu, E-mail: cxpan@whu.edu.cn [School of Physics and Technology, Center for Electron Microscopy and MOE Key Laboratory of Artificial Micro- and Nano-structures, Wuhan University, Wuhan 430072 (China); Center for Archaeometry, Wuhan University, Wuhan 430072 (China)

    2012-06-15

    In this paper, a kind of specific stalactitic product was found on the interior surface of a covered bronze wine vessel with loop-handle (Chinese name is you), which was fabricated in Shang Dynasty (1700 B.C.-1100 B.C.) and now is collected in Xiaogan Museum, Hubei province of China. The microstructures of the product were characterized systematically by using optical microscopy, scanning electron microscope, transmission electron microscope, X-ray diffraction, and Raman microscopy. The experimental results revealed that the product belonged to a kind of malachite with high purity and high crystallinity. The growth of the product was considered to be a possible reason that the vessel was overly airtight within a museum display cabinet besides a lid of the vessel, which made the excess of H{sub 2}O and CO{sub 2} gas concentrations inside the vessel during long-term storage. This corrosion product is very harmful to bronze cultural relics, because of a large amount of copper consumption from the matrix which will reduce its life. The growth mechanism of the specific stalactitic product and the suggestions for preservation of the similar bronze relics in museum were proposed. - Highlights: Black-Right-Pointing-Pointer The stalactitic product was the high purity and good crystallinity malachite. Black-Right-Pointing-Pointer Its growth was related to the excess of H{sub 2}O and CO{sub 2} gas concentrations in museum. Black-Right-Pointing-Pointer It is harmful to the bronzes, because copper will be consumed from the matrix. Black-Right-Pointing-Pointer The suggestions for preservation of the similar bronzes in museum were proposed.

  20. Hepatocyte growth factor is produced by blood and alveolar neutrophils in acute respiratory failure.

    Science.gov (United States)

    Jaffré, Sandrine; Dehoux, Monique; Paugam, Catherine; Grenier, Alain; Chollet-Martin, Sylvie; Stern, Jean-Baptiste; Mantz, Jean; Aubier, Michel; Crestani, Bruno

    2002-02-01

    We tested the novel hypothesis that neutrophils in the lung or the airspaces may produce hepatocyte growth factor (HGF) in ventilated patients with acute respiratory failure. Neutrophils were purified from blood and bronchoalveolar lavage (BAL) fluid samples from 16 mechanically ventilated patients who underwent BAL for a diagnostic workup of ventilator-acquired pneumonia. Most of the patients had pneumonia (n = 11). Ten nonventilated patients served as controls. Both blood and BAL neutrophils released HGF in vitro. Basal HGF secretion by blood neutrophils from controls was 823 (666) pg x ml(-1) x 10(-7) neutrophils (median, 25th-75th percentile) and doubled to 1,730 (1,684-2,316) pg x ml(-1) x 10(-7) neutrophils (P = 0.001) with lipopolysaccharide (LPS) stimulation. Basal HGF secretion by blood neutrophils from patients was similar [956 (655-2,140) pg x ml(-1) x 10(-7) neutrophils, P = 0.4] and doubled with LPS stimulation [2,767 (2,165-3,688) pg x ml(-1) x 10(-7) neutrophils, P < 0.0001 vs. controls]. Alveolar neutrophils released HGF in vitro [653 (397-1,209) pg x ml(-1) x 10(-7) neutrophils]. LPS stimulation did not significantly increase the HGF release from alveolar neutrophils [762 (434-1,305) pg x ml(-1) x 10(-7) neutrophils]. BAL HGF positively correlated with the BAL neutrophil count (P = 0.01, R = 0.58). We conclude that blood and alveolar neutrophils from patients with acute respiratory failure can produce HGF, a mitogenic factor that may enhance the alveolar repair process. PMID:11792636

  1. Chronic kidney disease, 24-h blood pressure and small vessel diseases are independently associated with cognitive impairment in lacunar infarct patients

    International Nuclear Information System (INIS)

    Although the relationships between chronic kidney disease (CKD) and cognitive impairment (CI) have been highlighted, the etiology of CI in CKD remains uncertain. Subjects comprised 224 consecutive patients with symptomatic lacunar infarction who underwent magnetic resonance imaging and ambulatory blood pressure monitoring (ABPM). Diurnal blood pressure (BP) patterns were categorized into three groups: dippers, non-dippers and risers. Lacunar infarcts (LIs), including both symptomatic and silent and diffuse white matter lesions (WMLs), were graded into three grades according to their degree. The results of kidney function were evaluated using estimated glomerular filtration rate (eGFR), categorized into three groups: stage 1, >60; stage 2, 30-60; and stage 3, -1 per 1.73 m2. There were 44 patients with CI. Confluent WMLs, including WML 2 and WML 3, were found in 36 patients (81.8%), and multiple lacunae including LI 2 and LI 3 were found in 30 patients (68.1%) with CI. Age >75 years (odds ratio (OR), 5.5; P-1 per 1.73 m2 (OR, 2.9; P-1 per 1.73 m2 (OR, 23.8; P75 years (OR, 4.1; P-1 per 1.73 m2 (OR, 3.7; P-1 per 1.73 m2 (OR, 8.7; P<0.05) were independently associated with WML grade 3. Extensive small vessel diseases, CKD and non-dipping status were independently associated with CI. CKD appears to mainly contribute to vascular CI, whereas possibilities of overlapping with other mechanisms such as degenerative CI cannot be excluded. Strict night time BP control and renoprotective treatment may be warranted to prevent CI. (author)

  2. Comparison of the Blood and Lymphatic Microvessel Density of Pleomorphic Adenoma and Basal Cell Adenoma

    OpenAIRE

    Andresa Borges Soares; Albina Altemani; Thais Ribeiro de Oliveira; Felipe de Oliveira Fonseca Rodrigues; Alfredo Ribeiro-Silva; Danilo Figueiredo Soave; Fabricio Passador-Santos; Suellen Trentin Brum; Marcelo Henrique Napimoga; Vera Cavalcanti de Araújo

    2015-01-01

    BACKGROUND Pleomorphic adenoma (PA) is the most common tumor of the salivary gland, while basal cell adenoma (BCA) is an uncommon neoplasm. Blood and lymphatic vessels are crucial for tumor metabolism. The aim of this study was to compare the blood and lymphatic vascular density and vascular and endothelial growth factor (VEGF) expression in PA and BCA tumors. In addition, cell proliferation was evaluated in these tumors. METHODS Blood and lymphatic vessel content, VEGF expression, and cell p...

  3. 3D-Gd-DTPA MR angiography of cerebral blood vessels: A comparison with conventional 3D-MR subtraction angiography

    International Nuclear Information System (INIS)

    Subtraction angiography based on 3D fast imaging techniques using rephasing and dephasing gradient pulses is widely used, resulting in angiograms which closely correlate with DSA. Similar angiograms can be obtained with 3D-gradient echo techniques before and after the administration of Gadolinium (Gd)-DTPA (0.1-0.2 mmol/kg) followed by image subtraction. As Gd-DTPA does not penetrate the blood-brain barrier, brain imaging is not altering by the contrast agent. Both techniques were compared in patients wihout vascular disease, venous sinus thrombosis, AV malformation and aneurysm. With both techniques the cerebro-vascular system was imaged favoring the venous system because of the more constant flow velocity and the lack of ECG synchronization. Gd-DTPA offers the advantage of the higher signal-to-noise ratio and is hampered by background superposition due to Gd-DTPA enhancement in non brain tissue. With both techniques vessels down to 1 mm can be imaged. (orig.)

  4. Photogrammetric measurement and visualization of blood vessel branching casting: a tool for quantitative accuracy tests of MR, CT, and DS angiography

    Science.gov (United States)

    D'Apuzzo, Nicola

    2000-12-01

    Currently three different angiographic techniques are used to measure and visualize major blood vessels in the human body: magnetic resonance (MR), computer tomography (CT) and digital subtraction (DS) angiography. Although these imaging systems have been already qualitatively compared, a quantitative assessment is still missing. The goal of this work is to provide a tool enabling a quantitative comparison of the three imaging techniques to an unbiased reference. MR-, CT- and DS-angiographies are first performed on a corpse. Then, a casting of the abdominal aorta and its main branches is prepared, removed from the body and measured with photogrammetric methods. The elongated and thin cast is fixed in a 3D frame with 16 signalized small spheres used for calibration and orientation purposes. Three fixed CCD cameras acquire triplets of images of the casting, which is turned in 8 positions. In order to perform multi-image matching, an artificial random texture is projected onto the object. For each triplet of images, a semi-automated matching process based on least squares matching determines a dense set of corresponding points. Their 3D coordinates are then computed by forward intersection, with a mean standard deviation of about 0.2 mm. The result from the 8 positions are merged together into a 3D point cloud and an adequate filter is applied to remove the noise and the redundancy in the overlapping regions. The paper depicts the basic design of the system and the measurement methods. Furthermore some preliminary results are presented.

  5. 17β-estradiol potentiates endothelium-dependent nitric oxide- and hyperpolarization-mediated relaxations in blood vessels of male but not female apolipoprotein-E deficient mice.

    Science.gov (United States)

    Kong, Billy W C; Vanhoutte, Paul M; Man, Ricky Y K; Leung, Susan W S

    2015-08-01

    The present study investigated the influence of gender on the changes underlying endothelial dysfunction in hyperlipidemia during aging. Isometric tension in rings (with endothelium) of the aortae and superior mesenteric arteries from apolipoprotein-E deficient mice was determined in wire myographs. Nitric oxide (NO)- and endothelium-dependent hyperpolarization (EDH)-mediated relaxations were smaller in the aortae and mesenteric arteries of 32weeks old males than eight weeks old males. In females, NO- and EDH-mediated relaxations were impaired only at 84weeks of age. The levels of reactive oxygen species were elevated in the blood vessels of 32weeks old males, but not females. Acute in vitro treatment with 17β-estradiol and apocynin improved NO- and EDH-mediated relaxations in 32weeks old males but not in 84weeks old males. Relaxations to SKA-31, activator of intermediate (IKCa) and small (SKCa) conductance calcium-activated potassium channels, were attenuated in the mesenteric arteries of 32weeks old males. Such impairment was restored by acute treatment with apocynin. These findings suggest that male hyperlipidemic mice develop endothelial dysfunction at an earlier age than females. This endothelial dysfunction is associated with impaired NO bioavailability and reduced IKCa and SKCa activity. Apocynin and 17β-estradiol restore the endothelial function only in younger male animals but not in older male or female animals. PMID:25869512

  6. Transformations for a generalized variable-coefficient Korteweg-de Vries model from blood vessels, Bose-Einstein condensates, rods and positons with symbolic computation

    International Nuclear Information System (INIS)

    The variable-coefficient Korteweg-de Vries (KdV)-typed models, although often hard to be studied, are of current interest in describing various real situations. Under investigation hereby is a large class of the generalized variable-coefficient KdV models with external-force and perturbed/dissipative terms. Recent examples of this class include those in blood vessels and circulatory system, arterial dynamics, trapped Bose-Einstein condensates related to matter waves and nonlinear atom optics, Bose gas of impenetrable bosons with longitudinal confinement, rods of compressible hyperelastic material and semiconductor heterostructures with positonic phenomena. In this Letter, based on symbolic computation, four transformations are proposed from this class either to the cylindrical or standard KdV equation when the respective constraint holds. The constraints have nothing to do with the external-force term. Under those transformations, such analytic solutions as those with the Airy, Hermit and Jacobian elliptic functions can be obtained, including the solitonic profiles. The roles for the perturbed and external-force terms to play are observed and discussed. Investigations on this class can be performed through the properties of solutions of cylindrical and standard KdV equations

  7. Grading vascularity from histopathological images based on traveling salesman distance and vessel size

    Science.gov (United States)

    Niazi, M. Khalid Khan; Hemminger, Jessica; Kurt, Habibe; Lozanski, Gerard; Gurcan, Metin

    2014-03-01

    Vascularity represents an important element of tissue/tumor microenvironment and is implicated in tumor growth, metastatic potential and resistence to therapy. Small blood vessels can be visualized using immunohistochemical stains specific to vascular cells. However, currently used manual methods to assess vascular density are poorly reproducible and are at best semi quantitative. Computer based quantitative and objective methods to measure microvessel density are urgently needed to better understand and clinically utilize microvascular density information. We propose a new method to quantify vascularity from images of bone marrow biopsies stained for CD34 vascular lining cells protein as a model. The method starts by automatically segmenting the blood vessels by methods of maxlink thresholding and minimum graph cuts. The segmentation is followed by morphological post-processing to reduce blast and small spurious objects from the bone marrow images. To classify the images into one of the four grades, we extracted 20 features from the segmented blood vessel images. These features include first four moments of the distribution of the area of blood vessels, first four moments of the distribution of 1) the edge weights in the minimum spanning tree of the blood vessels, 2) the shortest distance between blood vessels, 3) the homogeneity of the shortest distance (absolute difference in distance between consecutive blood vessels along the shortest path) between blood vessels and 5) blood vessel orientation. The method was tested on 26 bone marrow biopsy images stained with CD34 IHC stain, which were evaluated by three pathologists. The pathologists took part in this study by quantifying blood vessel density using gestalt assessment in hematopoietic bone marrow portions of bone marrow core biopsies images. To determine the intra-reader variability, each image was graded twice by each pathologist with two-week interval in between their readings. For each image, the ground

  8. Phthalate Levels in Cord Blood Are Associated with Preterm Delivery and Fetal Growth Parameters in Chinese Women

    OpenAIRE

    Yujing Huang; Junnan Li; Garcia, Jose M.; Hui Lin; Yanzhou Wang; Ping Yan; Lingqiao Wang; Yao Tan; Jiaohua Luo; Zhiqun Qiu; Ji-an Chen; Weiqun Shu

    2014-01-01

    Data concerning the effects of phthalate exposure on preterm delivery and fetal growth are limited in humans. In this paper, we assessed the relationship between 15 phthalate levels in cord blood and preterm delivery and fetal growth parameters in 207 Chinese women going into labor. Exposure to phthalates except DCHP was associated with gestational age reduction and preterm delivery (p

  9. Straw blood cell count, growth, inhibition and comparison to apoptotic bodies

    Directory of Open Access Journals (Sweden)

    Tomkins Jeffrey P

    2008-05-01

    Full Text Available Abstract Background Mammalian cells transform into individual tubular straw cells naturally in tissues and in response to desiccation related stress in vitro. The transformation event is characterized by a dramatic cellular deformation process which includes: condensation of certain cellular materials into a much smaller tubular structure, synthesis of a tubular wall and growth of filamentous extensions. This study continues the characterization of straw cells in blood, as well as the mechanisms of tubular transformation in response to stress; with specific emphasis placed on investigating whether tubular transformation shares the same signaling pathway as apoptosis. Results There are approximately 100 billion, unconventional, tubular straw cells in human blood at any given time. The straw blood cell count (SBC is 45 million/ml, which accounts for 6.9% of the bloods dry weight. Straw cells originating from the lungs, liver and lymphocytes have varying nodules, hairiness and dimensions. Lipid profiling reveals severe disruption of the plasma membrane in CACO cells during transformation. The growth rates for the elongation of filaments and enlargement of rabbit straw cells is 0.6~1.1 (μm/hr and 3.8 (μm3/hr, respectively. Studies using apoptosis inhibitors and a tubular transformation inhibitor in CACO2 cells and in mice suggested apoptosis produced apoptotic bodies are mediated differently than tubular transformation produced straw cells. A single dose of 0.01 mg/kg/day of p38 MAPK inhibitor in wild type mice results in a 30% reduction in the SBC. In 9 domestic animals SBC appears to correlate inversely with an animal's average lifespan (R2 = 0.7. Conclusion Straw cells are observed residing in the mammalian blood with large quantities. Production of SBC appears to be constant for a given animal and may involve a stress-inducible protein kinase (P38 MAPK. Tubular transformation is a programmed cell survival process that diverges from apoptosis

  10. Growth Kinetics, Characterization, and Plasticity of Human Menstrual Blood Stem Cells

    Directory of Open Access Journals (Sweden)

    Davood Mehrabani

    2016-03-01

    Full Text Available One of the readily available sources of mesenchymal stem cells (MSCs is menstrual blood-derived stem cells (Men-SCs, which exhibit characteristics similar to other types of MSCs. This study was performed to determine the growth kinetics, plasticity, and characterization of Men-SCs in women. During spring 2014 in the southern Iranian city of Shiraz, menstrual blood (5 mL was obtained from 10 women on their third day of menstruation in 2 age groups of 30 to 40 and 40 to 50 years old. Ficoll was used to separate the mononuclear cell fraction. After the Men-SCs were cultured, they were subcultured up to passage 4. Growth behavior and population doubling time were evaluated by seeding 5×104 cells into 12- and 24-well culture plates, and the colonies were enumerated. The expression of CD44, CD90, and CD34 was evaluated. The osteogenic potential was assessed by alizarin red staining. The Men-SCs were shown to be plastic adherent and spindle-shaped. Regarding the growth curves in the 12- and 24-well culture plates, it was demonstrated that in the women aged between 30 and 40 years, population doubling time was 55.5 and 62 hours, respectively, while these values in the women aged between 40 and 50 years were 70.4 and 72.4 hours, correspondingly. Positive expression of CD44 and CD90 and negative expression of CD34 were noted. In the osteogenic differentiation medium, the cells differentiated toward osteoblasts. As human Men-SCs are easily collectable without any invasive procedure and are a safe and rapid source of MSCs, they can be a good candidate for stem cell banking and cell transplantation in women.

  11. Determination of growth value thresholds for BACTEC PLUS aerobic blood culture vials.

    Science.gov (United States)

    McGowan, J E; Metchock, B G

    1992-04-01

    Growth value thresholds used to identify positive blood culture vials can be defined by users for each BACTEC NR-660 bacteremia detection instrument. Growth values were compared with the recovery of organisms from vials flagged as positive during the testing of 3.056 high-volume vials containing aerobic (BACTEC PLUS 26) medium over a 2-month period. Results showed that optimal threshold values for our use of these vials varied from those recommended by the manufacturer; if the thresholds defined from these data had been used during the study period, total vials flagged as positive from which no organisms were recovered (false alarms) would have been reduced from 181 (5.9/100 vials tested) to 71 (2.3/100 vials tested), with a minimal decrease in the identification of vials containing usual or occasional pathogens (hits). Adjustments of growth value thresholds by the individual user can make the use of BACTEC instruments more efficient by decreasing further processing of vials from which no organisms are recovered. PMID:1572964

  12. Thermal node of the growth vessel of apparatus of large-sized crystals of germanium growing by the immersible pivoted shaper method

    International Nuclear Information System (INIS)

    The construction of a thermal knot of the growth vessel of apparatus of large-sized crystals of germanium growing by the immersible pivoted shaper method is developed and tested. In a construction as a bowl material carbon and carbon-carbon composite bodied by pyrolytic carbon are used. Series of advantages of bowls from carbon-carbon composite material in the part of assurance of the given allocation of temperature on a surface of a bowl, heightening of a mechanical strength and fraction soot impurities lowering in a crystal is fixed. In experimental-industrial conditions crystals of germanium in diameter to 420 mm with high optical characteristic are received

  13. Involvement of calcitonin gene-related peptide (CGRP) receptors in insulin-induced vasodilatation in mesenteric resistance blood vessels of rats.

    Science.gov (United States)

    Mimaki, Y; Kawasaki, H; Okazaki, M; Nakatsuma, A; Araki, H; Gomita, Y

    1998-04-01

    1. The vascular effect of insulin in the mesenteric resistance blood vessel and the role of calcitonin generelated peptide (CGRP)-receptor in insulin-induced vascular responsiveness were investigated in rats. 2. The mesenteric vascular beds isolated from Wistar rats were perfused with Krebs solution, and perfusion pressure was measured with a pressure transducer. In preparations contracted by perfusion with Krebs solution containing methoxamine in the presence of guanethidine, the perfusion of insulin (from 0.1 to 3000 nM) caused a concentration-dependent decrease in perfusion pressure due to vasodilatation. The pD2 value and maximum relaxation (%) were 6.94+/-0.22 and 43.9+/-5.2, respectively. 3. This vasodilator response to insulin was unaffected by 100 nM propranolol (beta-adrenoceptor antagonist) plus 100 nM atropine (muscarinic cholinoceptor antagonist), 100 microM L-NG-nitroarginine (nitric oxide synthase inhibitor), 1 microM ouabain (Na+-K+ ATPase inhibitor), or 1 microM glibenclamide (ATP sensitive K+-channel inhibitor). 4. In preparations without endothelium, perfusion of insulin produced a marked vasodilatation. The pD2 value and maximum relaxation (%) were 7.62+/-0.21 and 81.0+/-4.6, respectively, significantly greater than in preparations with intact endothelium. 5. The vasodilator responses to insulin in the preparations without endothelium were significantly inhibited by CGRP[8 37], a CGRP receptor antagonist, whereas pretreatment with capsaisin, a toxin for CGRP-containing nerves, did not affect insulin-induced vasodilatation. 6. These results suggest that insulin induces non-adrenergic, non-cholinergic and endothelium-independent vasodilatation, which is partially mediated by CGRP receptors. PMID:9605576

  14. 基于结构特征的视网膜血管形态识别%Pattern recognition of retinal blood vessels based on nodes structure feature

    Institute of Scientific and Technical Information of China (English)

    赵晓芳; 林土胜

    2012-01-01

    针对视网膜眼底图像获取过程中眼球转动的问题,提出一种基于节点最近邻结构的具有旋转和平移不变性的视网膜血管形态识别方法.该方法利用节点的周边结构稳定性的特点来进行节点结构特征提取,进行图像相关结构匹配的判定.实验结果表明了该识别算法的有效性和可靠性,且不需要进行方位对准处理,具有较好地识别灵活性和实用性,正确识别率达到98.57%.%In order to overcome the effects of eye movement during the funds image acquisition stage, a method based on the node's adjacent structure for pattern recognition of retinal blood vessels is proposed. The method has the quality of rotation and translation invariance. Firstly, the node structure characteristics are extracted using the structural stability of the surrounding nodes, and then matching the image correlation structure. Experimental results on a database demonstrate the effectiveness and reliability of the recognition algorithm. It does not need to the complex pre-processing task for level alignment, and has a better adaptability and practicability. The accuracy rate of 98. 57 % is reached for the proposed method.

  15. Study on the relationship of blood vessel parameters between high-normal blood pressure pilots and optimal blood pressure pilots%正常高值血压与理想血压飞行员血管指标的意义

    Institute of Scientific and Technical Information of China (English)

    唐爽; 王新宴; 许波; 黄翠莹; 臧春梅; 文腾; 宋珍珍; 王建昌

    2015-01-01

    Objective To investigate the relationship of blood vessel parameters between high-normal blood pressure pilots and optimal blood pressure pilots.Methods According to their blood pressure level, 210 pilots were divided into two groups, namely, optimal blood pressure controls(n=111), high-normal blood pressure pilots(n=99). CASP and AIxHR75 were obtained by SphygmoCor device while baPWV and ABI were detected by Omron device.Results ①baPWV, CASP and AIxHR75 were higher in high-normal blood pressure group than those in optimal blood pressures group on statistical level(P0.05).baPWV增快的比例为7.4%.②CASP分布范围在80~120 mmHg,P50为100 mmHg,P95为112 mmHg.③中心动脉血压与外周血压差值分布范围在7~31 mmHg,P50为18 mmHg,P95为24 mmHg;基本呈正态分布.结论 正常高值血压与理想血压人群的血管指标差异有统计学意义,但其与临床意义是否对等尚需进一步大样本的研究;CASP应作为评估高血压病的诊断与治疗的指标之一.

  16. A Review of Retinal Vessel Segmentation Techniques and Algorithms

    OpenAIRE

    Mohd Imran Khan; Heena Shaikh; Anwar Mohd. Mansuri

    2011-01-01

    Retinal vessel segmentation algorithms are the critical components of circulatory blood vessel Analysis systems. We present a survey of vessel segmentation techniques and algorithms. We put the various vessel segmentation approaches and techniques in perspective by means of a classification of the existing research. While we have mainly targeted the segmentation of blood vessels, neurovascular structure in particular. We have divided vessel segmentation algorithms and techniques into six main...

  17. Determination of vascular endothelial growth factor (VEGF) in circulating blood: significance of VEGF in various leucocytes and platelets

    DEFF Research Database (Denmark)

    Werther, K; Christensen, Ib Jarle; Nielsen, Hans Jørgen

    2002-01-01

    contained considerable amounts of VEGF. In isolated lymphocytes and monocytes, VEGF was not present in measurable amounts. The number of neutrophils was significantly (p<0.0001) correlated to VEGF concentrations in lysed whole blood, but not to VEGF concentrations in plasma or serum. The number of platelets...... clotting. CONCLUSION: Circulating neutrophils contain considerable amounts of VEGF that contribute to high VEGF levels in lysed whole blood. VEGF in circulating platelets contributes to high VEGF levels in serum and lysed whole blood. Allowing whole blood samples to clot for between 2 and 6 h before serum......AIM: The sources of increased vascular endothelial growth factor (VEGF) concentrations in peripheral blood from cancer patients are not known in detail. The aim of the present study was to evaluate correlations between the VEGF content in isolated leucocyte subpopulations and VEGF concentrations in...

  18. Presence of intratumoral platelets is associated with tumor vessel structure and metastasis

    OpenAIRE

    Li, Rong; Ren, Meiping; Chen, Ni; Luo, Mao; Deng, Xin; Xia, Jiyi; Yu, Guang; Liu, Jinbo; HE Bing; Zhang, Xu; Zhang, Zhuo; Zhang, Xiao; Ran, Bing; Wu, Jianbo

    2014-01-01

    Background Platelets play a fundamental role in maintaining hemostasis and have been shown to participate in hematogenous dissemination of tumor cells. Abundant platelets were detected in the tumor microenvironment outside of the blood vessel, thus, platelet -tumor cell interaction outside of the bloodstream may play a role in regulating primary tumor growth and metastasis initiation. However, it is unclear that platelet depletion affects tumor vessel structure and dynamics. Methods Using thr...

  19. Glucagon-like peptide-2 (GLP-2) increases small intestinal blood flow and mucosal growth in ruminating calves

    DEFF Research Database (Denmark)

    Taylor-Edwards, C C; Burrin, D G; Holst, Jens Juul; McLeod, K R; Harmon, D L

    2011-01-01

    Glucagon-like peptide-2 (GLP-2) increases small intestinal mass and blood flow in nonruminants but its effect in ruminants is unknown. Eight Holstein calves with an ultrasonic flow probe around the superior mesenteric artery and catheters in the carotid artery and mesenteric vein were paired by age......, GLP-2 increased villus height, crypt depth, and BrdU-labeling in small intestinal segments. These results demonstrate that GLP-2 induces similar increases in small intestinal blood flow and growth in ruminants to those observed in nonruminants. Furthermore, GLP-2 increases small intestinal blood flow...

  20. Complement and Antibody-mediated Enhancement of Red Blood Cell Invasion and Growth of Malaria Parasites.

    Science.gov (United States)

    Biryukov, Sergei; Angov, Evelina; Landmesser, Mary E; Spring, Michele D; Ockenhouse, Christian F; Stoute, José A

    2016-07-01

    Plasmodium falciparum malaria is a deadly pathogen. The invasion of red blood cells (RBCs) by merozoites is a target for vaccine development. Although anti-merozoite antibodies can block invasion in vitro, there is no efficacy in vivo. To explain this discrepancy we hypothesized that complement activation could enhance RBC invasion by binding to the complement receptor 1 (CR1). Here we show that a monoclonal antibody directed against the merozoite and human polyclonal IgG from merozoite vaccine recipients enhanced RBC invasion in a complement-dependent manner and that soluble CR1 inhibited this enhancement. Sialic acid-independent strains, that presumably are able to bind to CR1 via a native ligand, showed less complement-dependent enhancement of RBC invasion than sialic acid-dependent strains that do not utilize native CR1 ligands. Confocal fluorescent microscopy revealed that complement-dependent invasion resulted in aggregation of CR1 at the RBC surface in contact with the merozoite. Finally, total anti-P. berghei IgG enhanced parasite growth and C3 deficiency decreased parasite growth in mice. These results demonstrate, contrary to current views, that complement activation in conjunction with antibodies can paradoxically aid parasites invade RBCs and should be considered in future design and testing of merozoite vaccines. PMID:27333049

  1. Prognostic value of insulin-like growth factor 1 and insulin-like growth factor binding protein 3 blood levels in breast cancer.

    NARCIS (Netherlands)

    Hartog, H.; Boezen, H.M.; Jong, M.M. de; Schaapveld, M.; Wesseling, J.; Graaf, W.T.A. van der

    2013-01-01

    High circulating insulin-like growth factor 1 (IGF-1) levels are firmly established as a risk factor for developing breast cancer, especially estrogen positive tumors. The effect of circulating IGF-1 on prognosis once a tumor is established is unknown. The authors explored the effect of IGF-1 blood

  2. Issues on the Use of White Blood Cell Growth Factors in Oncology Practice.

    Science.gov (United States)

    Lyman, Gary H

    2016-01-01

    Appropriate use of myeloid growth factors may reduce the risk of neutropenic complications including febrile neutropenia (FN) in patients receiving cancer chemotherapy. The recently updated American Society of Clinical Oncology (ASCO) Guidelines on the Use of the White Blood Cell Growth Factors recommends routine prophylaxis with these agents starting in the first cycle when the risk of FN is 20% or greater. However, the risks for neutropenic complications and the risk of serious adverse consequences from FN vary considerably with different chemotherapy regimens as well as other disease-, treatment-, and patient-specific risk factors. Considerably more information is now available on the major risk factors for FN. Multivariable risk models combining factors look promising but require further validation. Most clinical studies of myeloid growth factor prophylaxis assessed relative risk (RR) of FN but were not powered to evaluate the effect of prophylaxis on disease-free or overall survival. Accumulating evidence suggests, however, that the appropriate use of these agents in selected patients may improve both short-term and long-term survival by reducing the immediate risk of mortality accompanying patients with high-risk disease developing FN as well as improving disease-free and overall survival by enabling the delivery of full dose intensity chemotherapy and reducing the risk of disease recurrence in patients treated with curative intent. Further studies to evaluate risk factors and models for FN are needed to guide clinical and shared decision making for the optimal personalized use of these agents and offer patients at increased risk the best chance of long-term disease control. PMID:27249763

  3. Bone marrow cells participate in tumor vessel formation that supports the growth of Ewing’s sarcoma in the lung

    OpenAIRE

    Zhou, Zhichao; Stewart, Keri Schadler; Yu, Ling; Kleinerman, Eugenie S.

    2010-01-01

    An MHC-mismatch bone marrow (BM) transplant Ewing’s sarcoma mouse model was used to investigate whether BM cells participate in the vessel formation that support Ewing’s sarcoma lung metastasis. BM cells from H-2Kb/d donor mice were transplanted into sublethally irradiated H-2Kd recipient mice. Donor BM cells were identified using the H-2Kb marker. Engraftment was confirmed by identifying the H-2Kb IL-1β-type specific polymorphism. After engraftment highly lung metastatic TC71-PM4 cells were ...

  4. What Causes High Blood Pressure?

    Science.gov (United States)

    ... whether imbalances in this system cause high blood pressure. Blood Vessel Structure and Function Changes in the structure ... can affect blood pressure. Genetic Causes of High Blood Pressure Much of the understanding of the body systems ...

  5. What Is High Blood Pressure?

    Science.gov (United States)

    ... also known as blood vessels and capillaries. The pressure --- blood pressure --- is the result of two forces. The ... was last reviewed on 08/04/2014. High Blood Pressure • Home • About High Blood Pressure (HBP) Introduction What ...

  6. Intracerebral regional distribution of blood flow in response to uterine contractions in growth-restricted human fetuses.

    OpenAIRE

    Fu, Jing; Olofsson, Per

    2007-01-01

    Objective: To explore middle cerebral artery (MCA) and anterior cerebral artery (ACA) blood flow responses to superimposed acute hypoxemia in growth -restricted fetuses with and without established brain-sparing flow during basal conditions. Material and methods: 47 term fetuses suspected of growth restriction were exposed to an oxytocin challenge test with simultaneous cardiotocography and Doppler velocimetry in the umbilical artery, MCA and ACA. The MCA-to-ACA pulsatility index (PI) ratio w...

  7. Measurement of microbial DNA polymerase activity enables detection and growth monitoring of microbes from clinical blood cultures.

    Directory of Open Access Journals (Sweden)

    Daniel R Zweitzig

    Full Text Available Surveillance of bloodstream infections (BSI is a high priority within the hospital setting. Broth-based blood cultures are the current gold standard for detecting BSI, however they can require lengthy incubation periods prior to detection of positive samples. We set out to demonstrate the feasibility of using enzymatic template generation and amplification (ETGA-mediated measurement of DNA polymerase activity to detect microbes from clinical blood cultures. In addition to routine-collected hospital blood cultures, one parallel aerobic blood culture was collected and immediately refrigerated until being transported for ETGA analysis. After refrigeration holding and transport, parallel-collected cultures were placed into a BACTEC incubator and ETGA time-course analysis was performed. Of the 308 clinical blood cultures received, 22 were BACTEC positive, and thus were initially selected for ETGA time course analysis. The ETGA assay detected microbial growth in all 22 parallel-positive blood cultures in less time than a BACTEC incubator and also yielded genomic DNA for qPCR-based organism identification. In summary, feasibility of detecting microbes from clinical blood culture samples using the ETGA blood culture assay was demonstrated. Additional studies are being considered towards development of clinically beneficial versions of this methodology.

  8. Single peptide ligand-functionalized uniform hollow mesoporous silica nanoparticles achieving dual-targeting drug delivery to tumor cells and angiogenic blood vessel cells

    Directory of Open Access Journals (Sweden)

    Liu Y

    2015-03-01

    Full Text Available Yang Liu,1,2 Qing Chen,1 Ming Xu,3 Guannan Guan,1 Wen Hu,3 Ying Liang,2 Xiuli Zhao,1 Mingxi Qiao,1 Dawei Chen,1 Hao Liu2 1School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, 2Department of Pharmacy, Bengbu Medical College, Bengbu, 3College of Pharmaceutical Science, Soochow University, Suzhou, People’s Republic of China Background: The purpose of this study was to construct hollow mesoporous silica nanoparticles (HMSN decorated with tLyp-1 peptide (tHMSN for dual-targeting drug delivery to tumor cells and angiogenic blood vessel cells.Methods: HMSN were synthesized de novo using a novel cationic surfactant-assisted selective etching strategy and were then modified with tLyp-1. Multiple methods, including transmission electron microscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, bicinchoninic acid assay, and nitrogen adsorption and desorption isotherms, were used to characterize the tHMSN. Doxorubicin were chosen as the model cargo, and the uptake of doxorubicin-loaded tHMSN into MDA-MB-231 cells and human umbilical vein endothelial cells (HUVECs, as models of tumor cells and tumor neovascular endothelial cells, respectively, were observed and detected by confocal laser scanning microscopy and flow cytometry. An in vitro pharmacodynamic study and a study of the mechanism via which the nanoparticles were endocytosed were also performed.Results: HMSN with a highly uniform size and well oriented mesopores were synthesized. After tHMSN were characterized, enhanced uptake of the cargo carried by tHMSN into MDA-MB-231 cells and HUVECs compared with that of their unmodified counterparts was validated by confocal laser scanning microscopy and flow cytometry at the qualitative and quantitative levels, respectively. Further, the pharmacodynamic study suggested that, compared with their unmodified counterparts, doxorubicin-loaded tHMSN had an enhanced inhibitory effect on MDA-MB-231 cells and HUVECs in vitro. Finally, a

  9. Human blood-brain barrier insulin-like growth factor receptor

    International Nuclear Information System (INIS)

    Insulin-like growth factor (IGF)-1 and IGF-2, may be important regulatory molecules in the CNS. Possible origins of IGFs in brain include either de novo synthesis or transport of circulating IGFs from blood into brain via receptor mediated transcytosis mechanisms at the brain capillary endothelial wall, ie, the blood-brain barrier (BBB). In the present studies, isolated human brain capillaries are used as an in vitro model system of the human BBB and the characteristics of IGF-1 or IGF-2 binding to this preparation were assessed. The total binding of IGF-2 at 37 degrees C exceeded 130% per mg protein and was threefold greater than the total binding for IGF-1. However, at 37 degrees C nonsaturable binding equaled total binding, suggesting that endocytosis is rate limiting at physiologic temperatures. Binding studies performed at 4 degrees C slowed endocytosis to a greater extent than membrane binding, and specific binding of either IGF-1 or IGF-2 was detectable. Scatchard plots for either peptide were linear and the molar dissociation constant of IGF-1 and IGF-2 binding was 2.1 +/- 0.4 and 1.1 +/- 0.1 nmol/L, respectively. Superphysiologic concentrations of porcine insulin inhibited the binding of both IGF-1 (ED50 = 2 micrograms/mL) and IGF-2 (ED50 = 0.5 microgram/mL). Affinity cross linking of 125I-IGF-1, 125I-IGF-2, and 125I-insulin to isolated human brain capillaries was performed using disuccinimidylsuberate (DSS). These studies revealed a 141 kd binding site for both IGF-1 and IGF-2, and a 133 kd binding site for insulin

  10. PET/SPECT Imaging of Hindlimb Ischemia: Focusing on Angiogenesis and Blood Flow

    OpenAIRE

    Orbay, Hakan; Hong, Hao; Zhang, Yin; Cai, Weibo

    2012-01-01

    Peripheral artery disease (PAD) is a result of the atherosclerotic narrowing of blood vessels to the extremities, and the subsequent tissue ischemia can lead to the up-regulation of angiogenic growth factors and formation of new vessels as a recovery mechanism. Such formation of new vessels can be evaluated with various non-invasive molecular imaging techniques, where serial images from the same subjects can be obtained to allow the documentation of disease progression and therapeutic respons...

  11. An automated vessel segmentation of retinal images using multiscale vesselness

    International Nuclear Information System (INIS)

    The ocular fundus image can provide information on pathological changes caused by local ocular diseases and early signs of certain systemic diseases, such as diabetes and hypertension. Automated analysis and interpretation of fundus images has become a necessary and important diagnostic procedure in ophthalmology. The extraction of blood vessels from retinal images is an important and challenging task in medical analysis and diagnosis. In this paper, we introduce an implementation of the anisotropic diffusion which allows reducing the noise and better preserving small structures like vessels in 2D images. A vessel detection filter, based on a multi-scale vesselness function, is then applied to enhance vascular structures.

  12. Determination of vascular endothelial growth factor (VEGF) in circulating blood: significance of VEGF in various leucocytes and platelets

    DEFF Research Database (Denmark)

    Werther, K; Christensen, Ib Jarle; Nielsen, Hans Jørgen

    2002-01-01

    AIM: The sources of increased vascular endothelial growth factor (VEGF) concentrations in peripheral blood from cancer patients are not known in detail. The aim of the present study was to evaluate correlations between the VEGF content in isolated leucocyte subpopulations and VEGF concentrations ...

  13. Study on the Changes in Enzyme and Insulin-like Growth Factor-1 Concentrations in Blood Serum and Growth Characteristics of Velvet Antler during the Antler Growth Period in Sika Deer (Cervus nippon).

    Science.gov (United States)

    Park, Jaehyun; Jeon, Byongtae; Kang, Sungki; Oh, Mirae; Kim, Myonghwa; Jang, Seyoung; Park, Pyojam; Kim, Sangwoo; Moon, Sangho

    2015-09-01

    This study was conducted to investigate changes in blood enzyme parameters and to evaluate the relationship between insulin-like growth factor-1 (IGF-1), antler growth and body weight during the antler growth of sika deer (Cervus nippon). Serum enzyme activity and IGF-1 concentrations were measured in blood samples collected from the jugular and femoral veins at regular intervals during the antler growth period. Blood samples were taken in the morning from fasted stags (n = 12) which were healthy and showed no clinical signs of disease. Alfalfa was available ad libitum and concentrates were given at 1% of body weight to all stags. The experimental diet was provided at 9 am with water available at all times. There were no significant differences in alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase during antler growth, but alkaline phosphatase concentrations increased with antler growth progression, and the highest alkaline phosphatase concentration was obtained 55 days after antler casting. Serum IGF-1 concentrations measured from blood samples taken from the jugular vein during antler growth, determined that levels of IGF-1 was associated with body weight and antler growth patterns. Serum IGF-1 concentrations were higher at the antler cutting date than other sampling dates. Antler length increased significantly during antler growth (p<0.001), and there was a similar trend to between right and left beams. Body weight increased with antler growth but was not significant. Consequently it appeared that serum alkaline phosphatase concentration was related to antler growth and both antler growth and body weight were associated positively with IGF-1 concentrations during antler growth. PMID:26194228

  14. Vascular endothelium - Gatekeeper of vessel health.

    Science.gov (United States)

    Cahill, Paul A; Redmond, Eileen M

    2016-05-01

    The vascular endothelium is an interface between the blood stream and the vessel wall. Changes in this single cell layer of the artery wall are believed of primary importance in the pathogenesis of vascular disease/atherosclerosis. The endothelium responds to humoral, neural and especially hemodynamic stimuli and regulates platelet function, inflammatory responses, vascular smooth muscle cell growth and migration, in addition to modulating vascular tone by synthesizing and releasing vasoactive substances. Compromised endothelial function contributes to the pathogenesis of cardiovascular disease; endothelial 'dysfunction' is associated with risk factors, correlates with disease progression, and predicts cardiovascular events. Therapies for atherosclerosis have been developed, therefore, that are directed towards improving endothelial function. PMID:26994427

  15. Vascular endothelial growth factors enhance the permeability of the mouse blood-brain barrier.

    Directory of Open Access Journals (Sweden)

    Shize Jiang

    Full Text Available The blood-brain barrier (BBB impedes entry of many drugs into the brain, limiting clinical efficacy. A safe and efficient method for reversibly increasing BBB permeability would greatly facilitate central nervous system (CNS drug delivery and expand the range of possible therapeutics to include water soluble compounds, proteins, nucleotides, and other large molecules. We examined the effect of vascular endothelial growth factor (VEGF on BBB permeability in Kunming (KM mice. Human VEGF165 was administered to treatment groups at two concentrations (1.6 or 3.0 µg/mouse, while controls received equal-volume saline. Changes in BBB permeability were measured by parenchymal accumulation of the contrast agent Gd-DTPA as assessed by 7 T magnetic resonance imaging (MRI. Mice were then injected with Evans blue, sacrificed 0.5 h later, and perfused transcardially. Brains were removed, fixed, and sectioned for histological study. Both VEGF groups exhibited a significantly greater signal intensity from the cerebral cortex and basal ganglia than controls (P<0.001. Evans blue fluorescence intensity was higher in the parenchyma and lower in the cerebrovasculature of VEGF-treated animals compared to controls. No significant brain edema was observed by diffusion weighted MRI (DWI or histological staining. Exogenous application of VEGF can increase the permeability of the BBB without causing brain edema. Pretreatment with VEGF may be a feasible method to facilitate drug delivery into the CNS.

  16. Multiphase modelling of vascular tumour growth in two spatial dimensions

    OpenAIRE

    Hubbard, M. E.; Byrne, H. M.

    2012-01-01

    In this paper we present a continuum mathematical model of vascular tumour growth which is based on a multiphase framework in which the tissue is decomposed into four distinct phases and the principles of conservation of mass and momentum are applied to the normal/healthy cells, tumour cells, blood vessels and extracellular material. The inclusion of a diffusible nutrient, supplied by the blood vessels, allows the vasculature to have a nonlocal influence on the other phases. Two-dimensional c...

  17. Deterministic and probabilistic crack growth analysis for the JRC Ispra 1/5 scale pressure vessel n0 R2

    International Nuclear Information System (INIS)

    A deterministic and a probabilistic crack growth analysis is presented for the major defects found in the welds during ultrasonic pre-service inspection. The deterministic analysis includes first a determination of the number of load cycles until crack initiation, then a cycle-by-cycle calculation of the growth of the embedded elliptical cracks, followed by an evaluation of the growth of the semi-elliptical surface crack formed after the crack considered has broken through the wall and, finally, a determination of the critical crack size and shape. In the probabilistic analysis, a Monte-Carlo simulation is performed with a sample of cracks where the statistical distributions of the crack dimensions describe the uncertainty in sizing of the ultrasonic inspection. The distributions of crack depth, crack length and location are evaluated as a function of the number of load cycles. In the simulation, the fracture mechanics model of the deterministic analysis is employed for each random crack. The results of the deterministic and probabilistic crack growth analysis are compared with the results of the second in-service inspection where stable extension of some of the cracks had been observed. It is found that the prediction and the experiment agree only with a probability of the order of 5% or less

  18. Microscopical and elemental FESEM and Phenom ProX-SEM-EDS analysis of osteocyte- and blood vessel-like microstructures obtained from fossil vertebrates of the Eocene Messel Pit, Germany.

    Science.gov (United States)

    Cadena, Edwin

    2016-01-01

    The Eocene (∾48 Ma) Messel Pit in Germany is a UNESCO World Heritage Site because of its exceptionally preserved fossils, including vertebrates, invertebrates, and plants. Messel fossil vertebrates are typically characterized by their articulated state, and in some cases the skin, hair, feathers, scales and stomach contents are also preserved. Despite the exceptional macroscopic preservation of Messel fossil vertebrates, the microstructural aspect of these fossils has been poorly explored. In particular, soft tissue structures such as hair or feathers have not been chemically analyzed, nor have bone microstructures. I report here the preservation and recovery of osteocyte-like and blood vessel-like microstructures from the bone of Messel Pit specimens, including the turtles Allaeochelys crassesculpta and Neochelys franzeni, the crocodile Diplocynodon darwini, and the pangolin Eomanis krebsi. I used a Field Emission Scanning Electron Microscope (FESEM) and a Phenom ProX desktop scanning electron microscope (LOT-QuantumDesign) equipped with a thermionic CeB6 source and a high sensitivity multi-mode backscatter electron (BSE) for microscopical and elemental characterization of these bone microstructures. Osteocyte-like and blood vessel-like microstructures are constituted by a thin layer (∾50 nm thickness), external and internal mottled texture with slightly marked striations. Circular to linear marks are common on the external surface of the osteocyte-like microstructures and are interpreted as microbial troughs. Iron (Fe) is the most abundant element found in the osteocyte-like and blood vessel-like microstructures, but not in the bone matrix or collagen fibril-like microstructures. The occurrence of well-preserved soft-tissue elements (at least their physical form) establishes a promising background for future studies on preservation of biomolecules (proteins or DNA) in Messel Pit fossils. PMID:26819855

  19. Growth Performance, Carcass Characteristics, Antibody Titer and Blood Parameters in Broiler Chickens Fed Dietary Myrtle (Myrtus communis) Essential Oil as an Alternative to Antibiotic Growth Promoter

    OpenAIRE

    Mahmoodi Bardzardi M; Ghazanfari S; Sharifi SD

    2014-01-01

    This experiment was conducted to determine the effects of Myrtle Essential Oil (MEO) on growth performance, carcass characteristics, antibody titer and blood parameters of broiler chickens. A total of 200 Ross 308 broiler chickens were allocated to five dietary treatments with four replicates of 10 birds each. Dietary treatments were prepared by formulating a corn-soybean meal-based diet free of antibiotics (Control) and supplementing the basal diet with three levels of MEO at 100, 200, 300 m...

  20. Determination of adrenomedullin and endothelin in cord blood and their expressions in umbilical cord vessel of patients with pregnancy-induced hypertension

    International Nuclear Information System (INIS)

    Objective: To investigate the role of adrenomedullin (ADM) and endothelin-1 (ET-1) in the pathogenesis of pregnancy-induced hypertension (PIH). Methods: The plasma concentrations of ADM in human umbilical vein of PIH patients (n=30) and normal late trimester pregnancy women (n=12) were measured by radioimmunoassay. The expressions of ADM and ET-1 in umbilical cord vessel of PIH patients (n=40) and normal late trimester pregnancy women (n=12) were detected by immunohistochemistry (SABC). Results: 1) The plasma concentration of ADM in human umbilical vein of PIH patients was significantly higher than that of normal late trimester pregnancy women (P0.05). 2) The expression of ADM was found in endothelium and smooth muscle cell of umbilical cord vessel, and it increased with the serious degree of PIH. The expression of ET-1 was only found in endothelium of umbilical cord vessel, and it decreased with the serious degree of PIH. Conclusion: The changes of ADM and ET-1 in umbilical cord plasma and vessel may related to regulation of fetoplacental circulation in PIH

  1. Phthalate levels in cord blood are associated with preterm delivery and fetal growth parameters in Chinese women.

    Science.gov (United States)

    Huang, Yujing; Li, Junnan; Garcia, Jose M; Lin, Hui; Wang, Yanzhou; Yan, Ping; Wang, Lingqiao; Tan, Yao; Luo, Jiaohua; Qiu, Zhiqun; Chen, Ji-an; Shu, Weiqun

    2014-01-01

    Data concerning the effects of phthalate exposure on preterm delivery and fetal growth are limited in humans. In this paper, we assessed the relationship between 15 phthalate levels in cord blood and preterm delivery and fetal growth parameters in 207 Chinese women going into labor. Exposure to phthalates except DCHP was associated with gestational age reduction and preterm delivery (pphthalates and fetal growth parameters, many of which disappeared when analyses were adjusted for gestational age, especially in male infants (Only DEEP was associated with birth weight; DEP, DNHP, BBP, DNP with abdominal circumference; DEP, DBP, DCHP, DEHP with femur length in female infants. And DPP, DBEP was associated with birth length in male infants. pphthalates is associated with younger gestational age and preterm delivery. Also, phthalate exposure may adversely affect fetal growth parameters via gestational age reduction and preterm delivery with a significant gender effect. PMID:24503621

  2. Effect of Indigenous Herbs on Growth, Blood Metabolites and Carcass Characteristics in the Late Fattening Period of Hanwoo Steers

    OpenAIRE

    Kim, D. H.; Kim, K. H.; Nam, I. S.; S. S. Lee; C. W. Choi; Kim, W Y; KWON, E. G.; Lee, K. Y.; Lee, M. J.; Oh, Y K

    2013-01-01

    This study was conducted to evaluate the effects of indigenous herbal supplements on growth, blood metabolites and carcass characteristics in the late fattening period of Hanwoo steers. In a 6 month feeding trial, thirty Hanwoo steers (647±32 kg) were allotted to one of 5 treatment groups, control (basal diet contained lasalocid), licorice, clove, turmeric and silymarin, with six steers per pen. All groups received ad libitum concentrate and 1 kg rice straw/animal/d throughout the feeding tri...

  3. Mechanoinduction of lymph vessel expansion

    OpenAIRE

    Planas-Paz, Lara; Strilić, Boris; Goedecke, Axel; Breier, Georg; Fässler, Reinhard; Lammert, Eckhard

    2011-01-01

    Manipulating fluid pressure in the developing lymphatic system demonstrates that lymphatic endothelial cells are responsive to cell stretching, such that increased pressure promotes integrin-dependent VEGFR3 signalling, cell proliferation, and hence vessel growth.

  4. Comparative studies on the growth and reproductive performances of Rhodnius prolixus reared on different blood sources

    Directory of Open Access Journals (Sweden)

    José Eugenio P. Lima Gomes

    1990-09-01

    Full Text Available Host blood source was found to affect both the development and the reproductive performance of Rhodnius prolixus. The insects were reared on citrated human, rabbit, chicken, sheep and horse blood sources, through a membrane feeder, during an entire life cycle, from eggs to adults. Development and reproduction in terms of the number of unfed insects, number of moulting, mortality intermoulting period, number of egg/female, conversion of blood into egg (mg meal/egg and percentage of hatch as effective physiological parameters were investigated. Our results showed that human or rabbit blood meals were more nutritionally efficient than the other blood samples used because (i the insects developed faster, presented low mortality and about 80% of them reached the adult stage; and (ii females oviposited an average of at least 100% more eggs. The inefficiency of chicken and horse blood sources as diets for R. prolixus was manifested in (i a decrease of the amount of ingested blood and (ii only a reasonable nutritional quality. The inadequacy of sheep blood was observed by a mortality extremely high, poor moulting response and drastic reduction in egg production.

  5. Effects of growth, diving history, and high altitude on blood oxygen capacity in harbor seals

    Science.gov (United States)

    Kodama, A. M.; Elsner, R.; Pace, N.

    1977-01-01

    Blood volume and body composition for diving and nondiving harbor seals were measured at six-week intervals during a 10-month period of captitivity. Whole body hematocrit, red cell volume per kg of lean body mass, and total circulating hemoglobin per kg lean body mass were significantly higher in the diving group, but relatively large blood volumes expressed in terms of body weight (11-12%) were found in both groups. A pair of harbor seals exposed to high altitude for about three months registered significant increases in red cell volume, blood hemoglobin levels, and blood volume expressed in terms of body weight; results of alveolar gas analyses indicate that hyperventilation also occurred. These typical mammalian responses to hypoxia suggest that the harbor seal's large blood volume and high hemoglobin content are an expression of phylogenetic control, and that in spite of its adaptability to apnea during its diving life, the animal cannot be considered preacclimatized to high altitude.

  6. The Bipartite Rac1 Guanine Nucleotide Exchange Factor Engulfment and Cell Motility 1/Dedicator of Cytokinesis 180 (Elmo1/Dock180) Protects Endothelial Cells from Apoptosis in Blood Vessel Development*

    Science.gov (United States)

    Schäker, Kathrin; Bartsch, Susanne; Patry, Christian; Stoll, Sandra J.; Hillebrands, Jan-Luuk; Wieland, Thomas; Kroll, Jens

    2015-01-01

    Engulfment and cell motility 1/dedicator of cytokinesis 180 (Elmo1/Dock180) is a bipartite guanine nucleotide exchange factor for the monomeric GTPase Ras-related C3 botulinum toxin substrate 1 (Rac1). Elmo1/Dock180 regulates Rac1 activity in a specific spatiotemporal manner in endothelial cells (ECs) during zebrafish development and acts downstream of the Netrin-1/Unc5-homolog B (Unc5B) signaling cascade. However, mechanistic details on the pathways by which Elmo1/Dock180 regulates endothelial function and vascular development remained elusive. In this study, we aimed to analyze the vascular function of Elmo1 and Dock180 in human ECs and during vascular development in zebrafish embryos. In vitro overexpression of Elmo1 and Dock180 in ECs reduced caspase-3/7 activity and annexin V-positive cell number upon induction of apoptosis. This protective effect of Elmo1 and Dock180 is mediated by activation of Rac1, p21-activated kinase (PAK) and AKT/protein kinase B (AKT) signaling. In zebrafish, Elmo1 and Dock180 overexpression reduced the total apoptotic cell and apoptotic EC number and promoted the formation of blood vessels during embryogenesis. In conclusion, Elmo1 and Dock180 protect ECs from apoptosis by the activation of the Rac1/PAK/AKT signaling cascade in vitro and in vivo. Thus, Elmo1 and Dock180 facilitate blood vessel formation by stabilization of the endothelium during angiogenesis. PMID:25586182

  7. The bipartite rac1 Guanine nucleotide exchange factor engulfment and cell motility 1/dedicator of cytokinesis 180 (elmo1/dock180) protects endothelial cells from apoptosis in blood vessel development.

    Science.gov (United States)

    Schäker, Kathrin; Bartsch, Susanne; Patry, Christian; Stoll, Sandra J; Hillebrands, Jan-Luuk; Wieland, Thomas; Kroll, Jens

    2015-03-01

    Engulfment and cell motility 1/dedicator of cytokinesis 180 (Elmo1/Dock180) is a bipartite guanine nucleotide exchange factor for the monomeric GTPase Ras-related C3 botulinum toxin substrate 1 (Rac1). Elmo1/Dock180 regulates Rac1 activity in a specific spatiotemporal manner in endothelial cells (ECs) during zebrafish development and acts downstream of the Netrin-1/Unc5-homolog B (Unc5B) signaling cascade. However, mechanistic details on the pathways by which Elmo1/Dock180 regulates endothelial function and vascular development remained elusive. In this study, we aimed to analyze the vascular function of Elmo1 and Dock180 in human ECs and during vascular development in zebrafish embryos. In vitro overexpression of Elmo1 and Dock180 in ECs reduced caspase-3/7 activity and annexin V-positive cell number upon induction of apoptosis. This protective effect of Elmo1 and Dock180 is mediated by activation of Rac1, p21-activated kinase (PAK) and AKT/protein kinase B (AKT) signaling. In zebrafish, Elmo1 and Dock180 overexpression reduced the total apoptotic cell and apoptotic EC number and promoted the formation of blood vessels during embryogenesis. In conclusion, Elmo1 and Dock180 protect ECs from apoptosis by the activation of the Rac1/PAK/AKT signaling cascade in vitro and in vivo. Thus, Elmo1 and Dock180 facilitate blood vessel formation by stabilization of the endothelium during angiogenesis. PMID:25586182

  8. Dose-responses of zinc-methionine supplements on growth, blood metabolites and gastrointestinal development in sheep.

    Science.gov (United States)

    Jafarpour, N; Khorvash, M; Rahmani, H R; Pezeshki, A; Hosseini Ghaffari, M

    2015-08-01

    The effects of zinc-methionine (Zn-Met) supplementation on growth, blood metabolites and gastrointestinal development were investigated in two experiments with sheep. The objective of Experiment 1 was to determine the effects of Zn-Met supplementation on hormones and metabolites involved in growth and energy balance regulation, while Experiment 2 aimed to determine the effects of Zn-Met on feed intake, body weight, gastrointestinal development and liver glycogen concentration in lamb. The animals were assigned to groups with different concentrations of dietary Zn-Met (0, 0.4, 0.8 and 1.2 g/day) in both experiments. In Experiment 1, feeding different doses of Zn-Met increased plasma insulin-like growth factor 1 (IGF-1) concentration, but it linearly decreased plasma growth hormone (GH). No differences were observed in blood cortisol, insulin and glucose concentrations among the treatments. In Experiment 2, addition of Zn-Met to the diets did not lead to changes in the body weights of the lambs. Both average daily gain and dry matter intake (DMI) increased linearly with increasing concentrations of dietary Zn-Met. Lambs receiving Zn-Met showed higher liver glycogen concentrations than the control. While significant increases were observed in the villus height and crypt depth in the duodenum and jejunum as a result of Zn-Met supplementation, no change was detected in blood glucose concentrations (p > 0.05). Our findings suggest that dietary Zn-Met may improve growth, energy balance and gastrointestinal development in sheep. PMID:25580958

  9. Crack initiation and crack growth during thermal shock tests in the reactor pressure vessel of the HDR under corrosive medium conditions

    International Nuclear Information System (INIS)

    A survey is presented of the status of comprehensive thermal shock investigations performed at a reactor pressure vessel (RPV). In a separate group of experiments it was first studied which impacts are exerted on the undamaged RPV wall by fluid transients resembling emergency cooling conditions. Furthermore, crack formation and crack growth were enforced in selected wall zones by providing appropriate boundary conditions. It is proposed to load in a final step the wall zones heavily damaged by quasi-reality crack fields under conditions similar to emergency cooling. The investigations are performed to verify the capability of non-destructive testing methods and of computations (of temperatures, stresses, crack behaviour) to provide relevant information. The computations have yielded clear overestimations as well as underestimations. For instance, the investigations performed at the plant proper have produced the result that the thermal shocks acting on the RPV wall surface are substantially reduced by thermal mixing processes in water. In the subsequent computations of the RPV wall structure, rotation symmetric computer codes are found to fail completely under conditions of intensive local cooling. Finally - although the crack growth computations for the special cyclic thermal shocks under corrosive medium conditions were extremely conservative - it has been demonstrated, by use of acoustic emission analysis and other techniques that the present crack growth computations do not adequately take into account crucial parameters influencing the material behaviour. This means that the results obtained with laboratory-scale specimens cannot be safely transferred to the components under the testing conditions prevailing for the time being. (author)

  10. Medications for High Blood Pressure

    Science.gov (United States)

    ... dangerous as elevations of both systolic and diastolic pressure. Blood pressure is elevated for two main reasons: too ... and Angiotensin II receptor blockers (ARBs), reduce blood pressure by relaxing blood vessels Beta blockers, which also cause the heart ...

  11. Optimizing 18F-FDG PET/CT imaging of vessel wall inflammation: the impact of 18F-FDG circulation time, injected dose, uptake parameters, and fasting blood glucose levels

    International Nuclear Information System (INIS)

    18F-FDG PET is increasingly used for imaging of vessel wall inflammation. However, limited data are available on the impact of methodological variables, i.e. prescan fasting glucose, FDG circulation time and injected FDG dose, and of different FDG uptake parameters, in vascular FDG PET imaging. Included in the study were 195 patients who underwent vascular FDG PET/CT of the aorta and the carotids. Arterial standardized uptake values (meanSUVmax), target-to-background ratios (meanTBRmax) and FDG blood-pool activity in the superior vena cava (SVC) and the jugular veins (JV) were quantified. Vascular FDG uptake values classified according to the tertiles of prescan fasting glucose levels, the FDG circulation time, and the injected FDG dose were compared using ANOVA. Multivariate regression analyses were performed to identify the potential impact of all variables described on the arterial and blood-pool FDG uptake. Tertile analyses revealed FDG circulation times of about 2.5 h and prescan glucose levels of less than 7.0 mmol/l, showing a favorable relationship between arterial and blood-pool FDG uptake. FDG circulation times showed negative associations with aorticmeanSUVmax values as well as SVC and JV FDG blood-pool activity, but positive correlations with aortic and carotidmeanTBRmax values. Prescan glucose levels were negatively associated with aortic and carotidmeanTBRmax and carotidmeanSUVmax values, but were positively correlated with SVC blood-pool uptake. The injected FDG dose failed to show any significant association with vascular FDG uptake. FDG circulation times and prescan blood glucose levels significantly affect FDG uptake in the aortic and carotid walls and may bias the results of image interpretation in patients undergoing vascular FDG PET/CT. The injected FDG dose was less critical. Therefore, circulation times of about 2.5 h and prescan glucose levels less than 7.0 mmol/l should be preferred in this setting. (orig.)

  12. Silver Nitrate and Different Culture Vessels Influence High Frequency Microrhizome Induction In Vitro and Enhancement Growth of Turmeric Plantlet During Ex Vitro Acclimatization

    Directory of Open Access Journals (Sweden)

    Dikash Singh THINGBAIJAM

    2012-11-01

    Full Text Available Eleven cultivars of C. longa var. Lakadong were collected from Manipur having different topography. Curcumin content in different cultivars has been analyzed by using UV-Visible Spectrophotometer (100 Bio-Carry Spectrophotometer. The curcuminoids content were analyzed and quantified for identification of best quality cultivar. Thoubal Cultivar with highest curcumin content (9.44% was subjected for tissue culture technique using different culture vessels and silver nitrate for rapid multiplication and scaling up of microrhizome production. High multiplication rate of 27.40�0.47 were obtained in Murashige and Skoog�s medium supplemented with 3% sucrose + 1 mg L-1 ?-napthalene acetic acid, 4 mg L-1 6-benzyl-amino-purine and 11 ?M silver nitrate. Effect of different culture vessels and silver nitrate were studied for microrhizome and multiple shoots formation. Relatively higher rate of shoots along with microrhizome (17.5�0.32 can be seen in Growtek which was grown without any plant growth regulator. Growtek was used for scaling up of microrhizome production in vitro and utmost microrhizome was produced in liquid Murashige and Skoog�s medium supplemented with 8% sucrose, 1 mg L-1 ?-napthalene acetic acid, 4 mg L-1 6-benzyl-amino-purine and 11 ?M silver nitrate (36.25�0.27. Addition of silver nitrate in the medium resulted in improvement of microrhizome induction in vitro. Higher concentration of silver nitrate (33, 44, 66, 88 ?M negatively affected the microrhizome and shoot multiplication and shows inhibition of tissue response completely. Analysis of in vitro derived plantlets during acclimatization shows that the exogenous applied of silver nitrate shows superior growth as compared to control. 90-95% of plantlets with and 75-80% plantlets without silver nitrate treatment were successfully established under ex vitro acclimatization. The protocol could be utilized for large scale production of true-to-type plantlets and as alternative

  13. The anatomy and clinical application of sural blood vessel combined with free skin flap%腓肠血管联合游离皮瓣的解剖及临床应用

    Institute of Scientific and Technical Information of China (English)

    葛东江; 任志勇; 魏长月; 张坤; 张维彬; 王辉

    2014-01-01

    目的:探讨腓肠血管的解剖学特性及其联合游离皮瓣修复小腿大段组织缺损的临床疗效。方法实验研究:10具新鲜成人尸体标本,随机选择4具,每具结扎一侧肢体腓肠内侧动脉,另4具结扎腓肠外侧动脉,对侧肢体不结扎作为对照,对标本进行血管造影,观察结扎一侧腓肠内或腓肠外动脉后,该侧腓肠肌的血液供应;另外2具通过解剖学及小腿铸型标本观察该侧腓肠肌的血管交通支的来源、管径及部位。临床研究:回顾性分析2006年10月至2013年9月收治的19例小腿大段组织缺损患者资料,男11例,女8例;年龄10~40岁,平均32岁。其中12例采用腓肠内侧血管、7例采用腓肠外侧血管为受区血管,同时6例取游离胸脐皮瓣移植、8例取大腿前外侧皮瓣移植、2例取侧胸皮瓣移植、3例取背阔肌皮瓣移植修复组织缺损。创面面积为5 cm×10 cm~8 cm×37 cm,切取皮瓣面积为7 cm×10 cm~10 cm×30 cm。结果实验研究发现,小腿腓肠肌的血供为多源性,以腓肠动脉供血为主;当切断一侧腓肠血管时,来自腓肠肌内、外侧头之间的交通支和来自比目鱼肌交通支的血液供应该侧腓肠肌,且交通支管径粗、分支多、位置恒定。临床研究显示19例游离皮瓣全部成活,创面愈合时间13~29 d,其中一期愈合11例,二期愈合8例。随访时间12~24个月,皮瓣能耐受一定程度摩擦,均无明显感觉障碍。供区取自体腹部或大腿中厚皮片植皮覆盖,均一期愈合。结论腓肠血管位于腓肠肌深层,位置恒定,蒂长、易分离,管径较粗,适于吻合,腓肠血管联合游离皮瓣为小腿大段组织缺损修复提供一种新的治疗方法。%Objective To study the anatomical characteristics of sural blood vessel, and to explore the clinical effect of sural blood vessel combined with free skin flap in repairing large tissue

  14. Importance of Adding Wheat Germ in Diets of Growing Goats to Improve Some Components of Blood and Growth Performance

    International Nuclear Information System (INIS)

    This experiment was conducted to study the importance of supplementing wheat germ to the diet of growing local goats in Egypt for improving their some blood biochemical components as well as growth performance. Forty goats with 4 months age and average initial body weight 5 ± 0.5 kg were used in the present study which lasted 5 months. The animals were divided randomly into two equal groups; the 1st group fed basic diet without supplement (control) and the 2nd group of animals fed on the same basic diet with supplemented wheat germ at the rate of 5 g/head/day. The body weight was recorded at the beginning and the end of the experiment to calculate the daily gain of body weight for each animal. Blood samples were withdrawn at the end of experiment to estimate some blood parameters concentrations including total protein, albumin, globulin, urea, creatinine, total cholesterol, Ca, P, Mg, Zn, immunoglobulin G (IgG), total antioxidants and triiodothyronine (T3). The results showed that the addition of wheat germ by the rate of 5 gm/ head/ day to the diet of growing goats significantly increased the concentrations of total proteins, globulin, phosphorus, magnesium and zinc and led to significant decrease in the levels of total cholesterol. Significant improvement in levels of IgG, total antioxidants and T3 hormone in the blood were also observed. In addition, there was significant improvement in the feed efficiency of growing goats although total and daily gains of treated animals were affected by the diet supplement. It could be concluded that addition of wheat germ (5 g/head/day) led to modification of all studied blood components and led to improved feed efficiency in growing local goats, therefore, it could be recommended to use the wheat germ in growth stages because the economic return to this addition is preferable.

  15. The correlation of the serum leptin, insulin resistance, endocrine hormone, blood lipid and of simple obesity children and growth

    Institute of Scientific and Technical Information of China (English)

    Xiao-Yu Wang; Xiao-Yun Liu; Kai-Yu Xu

    2015-01-01

    Objective:To analyze the correlation of the serum leptin, insulin resistance, Endocrine hormone, blood lipid and of simple obesity children and growth.Methods:200 cases of simple obesity children (Study Group) and 200 cases of non obese children (control group) were studied, Fasting blood glucose(FBG), Glycosylated hemoglobin (HbAlc), the serum leptin detection (Leptin), insulin (INS), insulin resistance index (HOMA2-IR), growth hormone (GH), cortisol (cortisol), thyroid hormones and blood lipid indexes were detected.Results:Leptin, cortisol and T3 levels of study group were (21.39±2.29) g/L, (18.43±1.72) g/mL and (20.71±1.82) pmol/L, were significantly increased compared with the control group, and GH level was (3.15±0.41) g/L, was significantly reduced, the difference of all these indexes were statistically significant in two groups (P0.05), HbAlc, INS and HOMA2 - IR were respectively (5.82±0.87)%, (33.02-2.34) mIU/L, (3.31-0.54), compared with the control group obviously increase than the corresponding numerical of the control group, the difference of all these indexes have statistical significance in two groups (P<0.05). TC, TG and LDL-C of study group were (4.67±0.65) mmol/L, (1.62±0.45) mmol/L and (3.59±0.46) mmol/L, were significantly higher than those in the control group, while HLD-C was (1.10±0.24) mmol/L, was significantly lower (P<0.05). Conclusion:Children with simple obesity have leptin resistance, reduction of growth hormone and endocrine and lipid metabolism disorder, and seriously affect the normal growth and development of children.

  16. Stone vessels

    Czech Academy of Sciences Publication Activity Database

    Maříková Vlčková, Petra

    Prague : Charles University in Prague, 2010 - (Bárta, M.; Coppens, F.; Vymazalová, H.), s. 108-149 ISBN 978-80-7308-325-0 Institutional research plan: CEZ:AV0Z80020508 Keywords : stone vessels * Abusir South * Early Dynastic period * Old Kingdom * non-royal funerary architecture Subject RIV: AC - Archeology, Anthropology, Ethnology

  17. Iterative Vessel Segmentation of Fundus Images.

    Science.gov (United States)

    Roychowdhury, Sohini; Koozekanani, Dara D; Parhi, Keshab K

    2015-07-01

    This paper presents a novel unsupervised iterative blood vessel segmentation algorithm using fundus images. First, a vessel enhanced image is generated by tophat reconstruction of the negative green plane image. An initial estimate of the segmented vasculature is extracted by global thresholding the vessel enhanced image. Next, new vessel pixels are identified iteratively by adaptive thresholding of the residual image generated by masking out the existing segmented vessel estimate from the vessel enhanced image. The new vessel pixels are, then, region grown into the existing vessel, thereby resulting in an iterative enhancement of the segmented vessel structure. As the iterations progress, the number of false edge pixels identified as new vessel pixels increases compared to the number of actual vessel pixels. A key contribution of this paper is a novel stopping criterion that terminates the iterative process leading to higher vessel segmentation accuracy. This iterative algorithm is robust to the rate of new vessel pixel addition since it achieves 93.2-95.35% vessel segmentation accuracy with 0.9577-0.9638 area under ROC curve (AUC) on abnormal retinal images from the STARE dataset. The proposed algorithm is computationally efficient and consistent in vessel segmentation performance for retinal images with variations due to pathology, uneven illumination, pigmentation, and fields of view since it achieves a vessel segmentation accuracy of about 95% in an average time of 2.45, 3.95, and 8 s on images from three public datasets DRIVE, STARE, and CHASE_DB1, respectively. Additionally, the proposed algorithm has more than 90% segmentation accuracy for segmenting peripapillary blood vessels in the images from the DRIVE and CHASE_DB1 datasets. PMID:25700436

  18. Development of collateral vessels: A new paradigm in CAM angiogenesis model.

    Science.gov (United States)

    Gatne, Dipti P; Mungekar, Snehal; Addepalli, Veeranjaneyulu; Mohanraj, Krishnapriya; Ghone, Sanjeevani A; Rege, Nirmala N

    2016-01-01

    The chorioallantoic membrane (CAM) assay is one of the most widely used models to study angiogenesis. In this study, collateral vessel development is reported in CAM assay useful in analysis of angiogenesis. Four days old white Leghorn fertilized chicken eggs were inoculated with vehicle, standard or test angiogenesis inhibitor using standard protocol. Central vessel growth was seen tapering down and collateral vessels were developed from the lower side of the chorioallantoic membrane moving upward in 12 days old standard or test treated CAMs. In the absence of the central vessel, collateral blood supply helped in survival of embryos. Hence, development of collateral vessels was used for ranking of blood vessels and angiogenesis in addition to well-known standard parameters related to central vessel. The finding could differentiate molecules inhibiting angiogenesis with or without collateralization which is crucial in anti-angiogenic therapy used for cardiovascular diseases and cancer. This study proposes a new avenue to distinguish pro-angiogenic molecules from anti-angiogenic ones as well as anti-angiogenic molecules which may or may not support alternative vascularization pathway that would have great impact on future angiogenic and anti-angiogenic therapy. PMID:26390964

  19. Levels of Adipokines in Amniotic Fluid and Cord Blood Collected from Dichorionic-Diamniotic Twins Discordant for Fetal Growth

    Science.gov (United States)

    Park, Joong Shin; Norwitz, Errol R.; Panyavatthanasinh, Sitthysack; Kim, Sun Min; Lee, JoonHo; Park, Chan-Wook; Kim, Byoung Jae; Jun, Jong Kwan

    2016-01-01

    Objective To compare the concentrations of adipokines in amniotic fluid (AF) and cord blood collected from discordant dichorionic-diamniotic (DCDA) twin fetuses. Study Design The study population included DCDA twins discordant for fetal growth (birth weight difference >10%) who either underwent mid-trimester amniocentesis for routine clinical indication (Cohort 1) or whose amniotic fluid was collected at the time of delivery (Cohort 2). In both cohorts, cord blood was collected at delivery. Results A total of 92 twin pairs were enrolled (n = 49 in Cohort 1; n = 43 in Cohort 2). In Cohort 1, the concentrations of adiponectin (median, 68.5 ng/mL vs 61.4 ng/mL; ptwins. In Cohort 2, the concentration of serpin E1 (median, 246.0 ng/mL vs 182.8 ng/mL; ptwins, but no difference was noted in adiponectin and leptin concentrations. Levels of adiponectin (median, 10425.5 ng/mL vs 11552.0 ng/mL; ptwins whereas cord blood concentrations of serpin E1 (median, 15.5 ng/mL vs 13.3 ng/mL; ptwins. Conclusion In discordant DCDA twin pairs, concentrations of adiponectin, leptin, and serpin E1 in mid-trimester AF, AF at delivery, and cord blood at birth vary significantly but predictably between the smaller and larger twins. PMID:27135745

  20. The association between preoperative concentration of soluble vascular endothelial growth factor, perioperative blood transfusion, and survival in patients with primary colorectal cancer

    DEFF Research Database (Denmark)

    Werther, K; Christensen, Ib Jarle; Nielsen, Hans Jørgen

    2001-01-01

    OBJECTIVE: To investigate a possible association between the preoperative concentration of soluble vascular endothelial growth factor (sVEGF), perioperative blood transfusion, and survival in patients operated on for colorectal cancer. DESIGN: Retrospective study. SETTING: University hospital, De...