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Sample records for vascular rarefaction characteristic

  1. Cutaneous chronic graft-versus-host disease does not have the abnormal endothelial phenotype or vascular rarefaction characteristic of systemic sclerosis.

    Directory of Open Access Journals (Sweden)

    Jo Nadine Fleming

    2009-07-01

    Full Text Available The clinical and histologic appearance of fibrosis in cutaneous lesions in chronic graft-versus -host disease (c-GVHD resembles the appearance of fibrosis in scleroderma (SSc. Recent studies identified distinctive structural changes in the superficial dermal microvasculature and matrix of SSc skin. We compared the dermal microvasculature in human c-GVHD to SSc to determine if c-GVHD is a suitable model for SSc.We analyzed skin biopsies of normal controls (n = 24, patients with SSc (n = 30 and c-GVHD with dermal fibrosis (n = 133. Immunostaining was employed to identify vessels, vascular smooth muscle, dermal matrix, and cell proliferation. C-GVHD and SSc had similar dermal matrix composition and vascular smooth muscle pathology, including intimal hyperplasia. SSc, however, differed significantly from c-GVHD in three ways. First, there were significantly fewer (p = 0.00001 average vessels in SSc biopsies (9.8 when compared with c-GVHD (16.5. Second, in SSc, endothelial markers were decreased significantly (19/19 and 12/14 for VE cadherin and vWF (p = <0.0001 and <0.05, respectively. In contrast, 0/13 c-GVHD biopsies showed loss of staining with canonical endothelial markers. Third, c-GVHD contained areas of microvascular endothelial proliferation not present in the SSc biopsies.The sclerosis associated with c-GVHD appears to resemble wound healing. Focal capillary proliferation occurs in early c-GVHD. In contrast, loss of canonical endothelial markers and dermal capillaries is seen in SSc, but not in c-GVHD. The loss of VE cadherin in SSc, in particular, may be related to microvascular rarefaction because VE cadherin is necessary for angiogenesis. C-GVHD is a suitable model for studying dermal fibrosis but may not be applicable for studying the microvascular alterations characteristic of SSc.

  2. Effects of Gas Rarefaction on Dynamic Characteristics of Micro Spiral-Grooved Thrust Bearing

    OpenAIRE

    Liu, Ren; Wang, Xiao-Li; Zhang, Xiao-Qing

    2012-01-01

    The effects of gas-rarefaction on dynamic characteristics of micro spiral-grooved-thrust-bearing are studied. The Reynolds equation is modified by the first order slip model, and the corresponding perturbation equations are then obtained on the basis of the linear small perturbation method. In the converted spiral-curve-coordinates system, the finite-volume-method (FVM) is employed to discrete the surface domain of micro bearing. The results show, compared with the continuum-flow model, that ...

  3. Effects of Gas Rarefaction on Dynamic Characteristics of Micro Spiral-Grooved Thrust Bearing.

    Science.gov (United States)

    Liu, Ren; Wang, Xiao-Li; Zhang, Xiao-Qing

    2012-04-01

    The effects of gas-rarefaction on dynamic characteristics of micro spiral-grooved-thrust-bearing are studied. The Reynolds equation is modified by the first order slip model, and the corresponding perturbation equations are then obtained on the basis of the linear small perturbation method. In the converted spiral-curve-coordinates system, the finite-volume-method (FVM) is employed to discrete the surface domain of micro bearing. The results show, compared with the continuum-flow model, that under the slip-flow regime, the decrease in the pressure and stiffness become obvious with the increasing of the compressibility number. Moreover, with the decrease of the relative gas-film-thickness, the deviations of dynamic coefficients between slip-flow-model and continuum-flow-model are increasing.

  4. Abdominal vascular syndromes: characteristic imaging findings

    International Nuclear Information System (INIS)

    Cardarelli-Leite, Leandro; Velloni, Fernanda Garozzo; Salvadori, Priscila Silveira; Lemos, Marcelo Delboni; D'Ippolito, Giuseppe

    2016-01-01

    Abdominal vascular syndromes are rare diseases. Although such syndromes vary widely in terms of symptoms and etiologies, certain imaging findings are characteristic. Depending on their etiology, they can be categorized as congenital - including blue rubber bleb nevus syndrome, Klippel-Trenaunay syndrome, and hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome) - compressive - including 'nutcracker' syndrome, median arcuate ligament syndrome, Cockett syndrome (also known as May-Thurner syndrome), and superior mesenteric artery syndrome. In this article, we aimed to illustrate imaging findings that are characteristic of these syndromes, through studies conducted at our institution, as well as to perform a brief review of the literature on this topic. (author)

  5. Abdominal vascular syndromes: characteristic imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Cardarelli-Leite, Leandro; Velloni, Fernanda Garozzo; Salvadori, Priscila Silveira; Lemos, Marcelo Delboni; D' Ippolito, Giuseppe, E-mail: leandrocleite@gmail.com [Universidade Federal de Sao Paulo (EPM/UNIFESP), Sao Paulo, SP (Brazil). Escola Paulista de Mediciana. Departmento de Diagnostico por Imagem

    2016-07-15

    Abdominal vascular syndromes are rare diseases. Although such syndromes vary widely in terms of symptoms and etiologies, certain imaging findings are characteristic. Depending on their etiology, they can be categorized as congenital - including blue rubber bleb nevus syndrome, Klippel-Trenaunay syndrome, and hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome) - compressive - including 'nutcracker' syndrome, median arcuate ligament syndrome, Cockett syndrome (also known as May-Thurner syndrome), and superior mesenteric artery syndrome. In this article, we aimed to illustrate imaging findings that are characteristic of these syndromes, through studies conducted at our institution, as well as to perform a brief review of the literature on this topic. (author)

  6. Impaired skin capillary recruitment in essential hypertension is caused by both functional and structural capillary rarefaction

    NARCIS (Netherlands)

    Serne, EH; Gans, ROB; ter Maaten, JC; Tangelder, GJ; Donker, AJM; Stehouwer, CDA

    Capillary rarefaction occurs in many tissues in patients with essential hypertension and may contribute to an increased vascular resistance and impaired muscle metabolism. Rarefaction may be caused by a structural (anatomic) absence of capillaries, functional nonperfusion, or both. The aim of this

  7. Ion rarefaction waves and associated phenomena

    International Nuclear Information System (INIS)

    Coates, A.J.

    1982-01-01

    This thesis contains an experimental and theoretical study of the response of a plasma to the motion of the positive space-charge sheath which bounds it . It is known theoretically that, if a sheath edge is moved at a speed less than the speed of ion acoustic waves, a region of ion rarefaction propagates into the plasma at the ion acoustic speed. Some calculations are described which include the effects of an initial presheath by constructing a one-dimensional plasma solution where a production term balances the losses of ions to the walls. The plasma response to the motion of one boundary is found using the method of characteristics with appropriate boundary conditions. Ion rarefaction waves are associated with expanding sheaths while ion 'enhancement' waves (compressive features) are formed on sheath collapse. In each case the wavefront moves at the local ion acoustic speed which includes the effects of ion drift. The presence of the presheath is essential to the generation of enhancements. The constructional details of a multidipole device are discussed, and the results of Langmuir probe and ion acoustic wave experiments are used to determine the parameters of a quiescent argon plasma. Some experiments on moving sheaths in such a plasma are then considered. (author)

  8. Diverse Imaging characteristics of a mandibular intraosseous vascular lesion

    International Nuclear Information System (INIS)

    Handa, Hina; Naidu, Giridhar S.; Dara, Balaji Gandhi Babu; Deshpande, Ashwini; Raghavendra, Raju

    2014-01-01

    Intraosseous vascular lesions of the maxillofacial region are rare, and the differential diagnosis of intraosseous vascular malformations from other jaw lesions can be challenging. In the present case, magnetic resonance imaging and three-dimensional computed tomographic angiography (CTA) was used for diagnosis, and the lesion was treated with surgical excision. Diverse characteristics such as the 'honeycomb' and 'sunburst' radiographic appearances and the absence of major peripheral feeder vessels in the CTA were noted. Intraosseous vascular malformations have a varied radiographic appearance, and the nomenclature of these lesions is equally diverse, with several overlapping terms. Pathologists do not generally differentiate among intraosseous vascular lesions on the basis of histopathology, although these lesions may present with contrasting immunohistochemical and clinical behaviors requiring varied treatment strategies. This case report highlights the need for multiple imaging modalities to differentiate among vascular lesions, as well as to better understand the behaviors of these unique lesions.

  9. Rarefaction acceleration in magnetized gamma-ray burst jets

    Science.gov (United States)

    Sapountzis, Konstantinos; Vlahakis, Nektarios

    2013-09-01

    Relativistic jets associated with long/soft gamma-ray bursts are formed and initially propagate in the interior of the progenitor star. Because of the subsequent loss of their external pressure support after they cross the stellar surface, these flows can be modelled as moving around a corner. A strong steady-state rarefaction wave is formed, and the sideways expansion is accompanied by a rarefaction acceleration. We investigate the efficiency and the general characteristics of this mechanism by integrating the steady-state, special relativistic, magnetohydrodynamic equations, using a special set of partial exact solutions in planar geometry (r self-similar with respect to the `corner'). We also derive analytical approximate scalings in the ultrarelativistic cold/magnetized, and hydrodynamic limits. The mechanism is more effective in magnetized than in purely hydrodynamic flows. It substantially increases the Lorentz factor without much affecting the opening of the jet; the resulting values of their product can be much greater than unity, allowing for possible breaks in the afterglow light curves. These findings are similar to the ones from numerical simulations of axisymmetric jets by Komissarov et al. and Tchekhovskoy et al., although in our approach we describe the rarefaction as a steady-state simple wave and self-consistently calculate the opening of the jet that corresponds to zero external pressure.

  10. Modeling of the 35-mm Rarefaction Wave Gun

    National Research Council Canada - National Science Library

    Coffee, Terence P

    2006-01-01

    .... The opening of the breech creates a rarefaction wave that travels down the bore of the gun. If the timing is done correctly, the rarefaction wave will not reach the projectile until at or after muzzle exit...

  11. Clinical and imaging characteristics of the vascular dementia. Preliminary studies

    International Nuclear Information System (INIS)

    Gomez Viera, Nelson; Rivero Arias, Edmundo; Perez Nellar, Jesus; Begueria Santos, Ramon; Arias Sifontes, William; Raiteris Flores, Juan

    1997-01-01

    A descriptive prospective study was carried out in 41 patients presenting with vascular dementia from Habana Vieja municipality, Havana City, in order to know some of the clinical and imaging characteristics of this disease. The main risk factors observed were the history of cerebrovascular disease and arterial hypertension. Depression, sleeping disorders and focal and pseudo bulbar neurologic signs were the most frequent clinical findings. Folstein neuropsychological test evidenced an important disorder of attention, calculation, the evocation memory and orientation. According to this test, 29 % of the patients had a severe dementia and nearly 50 % showed a severe handicap. The most frequent imaging findings observed in the computerized axial tomography of the cranium were cerebral atrophy, and single or multiple infarctions. Multiple cerebral infarctions, the lacunar status, subcortical encephalopathy of Binswanger, and single infarction located in cerebral areas related to cognition were considered as possible psychopathological mechanisms associated with the disease

  12. Microvascular remodelling in preeclampsia: quantifying capillary rarefaction accurately and independently predicts preeclampsia.

    Science.gov (United States)

    Antonios, Tarek F T; Nama, Vivek; Wang, Duolao; Manyonda, Isaac T

    2013-09-01

    Preeclampsia is a major cause of maternal and neonatal mortality and morbidity. The incidence of preeclampsia seems to be rising because of increased prevalence of predisposing disorders, such as essential hypertension, diabetes, and obesity, and there is increasing evidence to suggest widespread microcirculatory abnormalities before the onset of preeclampsia. We hypothesized that quantifying capillary rarefaction could be helpful in the clinical prediction of preeclampsia. We measured skin capillary density according to a well-validated protocol at 5 consecutive predetermined visits in 322 consecutive white women, of whom 16 subjects developed preeclampsia. We found that structural capillary rarefaction at 20-24 weeks of gestation yielded a sensitivity of 0.87 with a specificity of 0.50 at the cutoff of 2 capillaries/field with the area under the curve of the receiver operating characteristic value of 0.70, whereas capillary rarefaction at 27-32 weeks of gestation yielded a sensitivity of 0.75 and a higher specificity of 0.77 at the cutoff of 8 capillaries/field with area under the curve of the receiver operating characteristic value of 0.82. Combining capillary rarefaction with uterine artery Doppler pulsatility index increased the sensitivity and specificity of the prediction. Multivariable analysis shows that the odds of preeclampsia are increased in women with previous history of preeclampsia or chronic hypertension and in those with increased uterine artery Doppler pulsatility index, but the most powerful and independent predictor of preeclampsia was capillary rarefaction at 27-32 weeks. Quantifying structural rarefaction of skin capillaries in pregnancy is a potentially useful clinical marker for the prediction of preeclampsia.

  13. Rarefaction wave in relativistic steady magnetohydrodynamic flows

    Energy Technology Data Exchange (ETDEWEB)

    Sapountzis, Konstantinos, E-mail: ksapountzis@phys.uoa.gr; Vlahakis, Nektarios, E-mail: vlahakis@phys.uoa.gr [Faculty of Physics, University of Athens, 15784 Zografos, Athens (Greece)

    2014-07-15

    We construct and analyze a model of the relativistic steady-state magnetohydrodynamic rarefaction that is induced when a planar symmetric flow (with one ignorable Cartesian coordinate) propagates under a steep drop of the external pressure profile. Using the method of self-similarity, we derive a system of ordinary differential equations that describe the flow dynamics. In the specific limit of an initially homogeneous flow, we also provide analytical results and accurate scaling laws. We consider that limit as a generalization of the previous Newtonian and hydrodynamic solutions already present in the literature. The model includes magnetic field and bulk flow speed having all components, whose role is explored with a parametric study.

  14. Investigations of leakage mechanisms and its influences on a micro swing engine considering rarefaction effects

    International Nuclear Information System (INIS)

    Zhou, Xiong; Zhang, Zhenyu; Kong, Wenjun; Du, Ning

    2016-01-01

    Highlights: • Mechanisms of the leakage flow in different flow regimes have been studied. • The leakage flow regime and patterns in the micro swing engine are presented. • Slip on the walls has a larger effect on leakage flow with decreasing the gap. • Rarefaction effects on the engine performance have been investigated. - Abstract: Considering rarefaction effects, this paper investigated mechanisms of the clearance leakage and its influences on a micro swing engine for the micro power generation by employing three different flow models named as discrete velocity direction (DVD) model, Navier-Stokes equations with slip boundary conditions (NS-slip) and no-slip boundary conditions (NS-no slip). Using the DVD model, this paper firstly studied leakage mechanisms of a micro Couette-Poisueille flow. Factors which control the leakage in different regimes were obtained. Furthermore, the system-level predictions of the clearance leakage in the micro swing engine have been conducted by solving the Navier-Stokes equations. The leakage flow regime, patterns and characteristics were presented. Results by NS-slip and NS-no slip were compared to study the rarefaction effects. Finally, investigations of the engine size and the gap height on the engine performance have been conducted. The significance of the leakage in different engine size regimes was presented, and the results show that rarefaction effects affect the indicated thermal efficiency greatly with the decrease of the engine size scale.

  15. The mean and variance of phylogenetic diversity under rarefaction.

    Science.gov (United States)

    Nipperess, David A; Matsen, Frederick A

    2013-06-01

    Phylogenetic diversity (PD) depends on sampling depth, which complicates the comparison of PD between samples of different depth. One approach to dealing with differing sample depth for a given diversity statistic is to rarefy, which means to take a random subset of a given size of the original sample. Exact analytical formulae for the mean and variance of species richness under rarefaction have existed for some time but no such solution exists for PD.We have derived exact formulae for the mean and variance of PD under rarefaction. We confirm that these formulae are correct by comparing exact solution mean and variance to that calculated by repeated random (Monte Carlo) subsampling of a dataset of stem counts of woody shrubs of Toohey Forest, Queensland, Australia. We also demonstrate the application of the method using two examples: identifying hotspots of mammalian diversity in Australasian ecoregions, and characterising the human vaginal microbiome.There is a very high degree of correspondence between the analytical and random subsampling methods for calculating mean and variance of PD under rarefaction, although the Monte Carlo method requires a large number of random draws to converge on the exact solution for the variance.Rarefaction of mammalian PD of ecoregions in Australasia to a common standard of 25 species reveals very different rank orderings of ecoregions, indicating quite different hotspots of diversity than those obtained for unrarefied PD. The application of these methods to the vaginal microbiome shows that a classical score used to quantify bacterial vaginosis is correlated with the shape of the rarefaction curve.The analytical formulae for the mean and variance of PD under rarefaction are both exact and more efficient than repeated subsampling. Rarefaction of PD allows for many applications where comparisons of samples of different depth is required.

  16. Experimental comparison study of the tissue characteristics in transjugular intrahepatic portosystemic shunt and vascular stent

    International Nuclear Information System (INIS)

    Lu Qin; An Yanli; Deng Gang; Fang Wen; Zhu Guangyu; Niu Huanzhang; Yu Hui; Li Guozhao; Teng Gaojun; Wang Zhen; Wei Xiaoying

    2009-01-01

    Objective: To investigate the tissue characteristics within vascular stent and transjugular intrahepatic portosystemic shunt(TIPS) on swine and to provide more information for the understanding and prevention of vascular stent and TIPS restenosis. Methods: Animal models for TIPS were built in 6 swine and vascular stents were implanted in iliac veins simultaneously. 14-28 days after the operation, the 6 swine were killed to remove the TIPS and vascular stent and the pathological examinations were performed on the tissues within the shunt and stent. The similarities and differences of the tissues within the shunt and stent were analyzed with Krttskal Wallis test. Results: Restenosis of TIPS occurred in 4 models and complete occlusion were seen in 2, while all vascular stents were patent and coated with a thin layer of intimal tissue. Electron microscopic results showed that the tissues in restenotic TIPS were loose and with more extra matrix and fibers, and less smooth muscle, fibroblastic and myofibroblastic cells with different and irregular shape and rich secretory granules. The tissues in patent TIPS contained more extra fibers, smooth muscle and fibroblastic cells with normal organelle. The intimal tissues in vascular stent contained more fibers and fibroblasts cells, less smooth muscle cells. On immunohistochemical staining, the tissues in restenotic and patent TIPS as well as the intimal tissues in vascular stent had strong positive expression for anti-SMC- actin-α, the expression were gradually weakened for PCNA, the intimal tissues in vascular stent had a strong positive expression for vimentin, while the expression of the tissues in restenotic and patent TIPS were weakened gradually. For myoglobulin, the tissues in restenotic TIPS had weakly positive expression, the expression in patent TIPS and vascular stent were almost negative. Western blot results for TGF-β showed that the absorbance ratios of the intima tissues in vascular stent, normal vascular

  17. Rarefaction Effects in Low Reynolds Number Subsonic and Transonic Aerodynamics

    Science.gov (United States)

    Pekardan, Cem

    The quantification of rarefaction effects for low Reynolds number (Reefficient. It was also shown that when the Reynolds number of the flow decreased from 10,000 to 1,000, slip effects become dominant. The flow becomes fully rarefied at Re=10. Furthermore, rarefaction effects were quantified for the NACA 0007 and the NACA 2407 at 0 and 10 degrees of angle of attack to investigate the effects of thickness, camber, and the angle of attack. It was observed that flow separation due to increase in thickness resulted in higher rarefaction effects. It was concluded that thin airfoils with very smooth shape changes minimize continuum breakdown / rarefaction effects. Rarefied gas phenomena that only appear in low pressures (such as thermal effects) can be exploited for performance enhancement of applications in slightly rarefied aerodynamics. In this study, feasibility and advantages of using thermal control to reduce drag and mitigate vortex shedding for airfoils are studied. NACA 0012 airfoil with a temperature difference applied between the upper and the lower surface is simulated in the continuum regime with a Navier-Stokes solver and compared to experimental data for verification of parameters and turbulence modelling. At lower pressures, an elevated temperature on the bottom surface of the airfoil is investigated to create lift and understand the rarefaction effects. Continuum NS results were compared to the rarefied ES-BGK solver for the rarefaction effects. It was shown that an elevated temperature enhances the lift by 25 % and reduces the drag at high angles of attack. In the second part, a temperature gradient on the upper surface is applied and it was seen that drag is reduced by 4 % and vortex shedding frequency is reduced due to gradients introduced in the flow by thermal transpiration.

  18. The relationship between vascular and metabolic characteristics of primary breast tumours

    International Nuclear Information System (INIS)

    Semple, Scott I.K.; Gilbert, Fiona J.; Redpath, Thomas W.; Staff, Roger T.; Ahearn, Trevor S.; Welch, Andrew E.; Heys, Steven D.; Hutcheon, Andrew W.; Smyth, Elizabeth H.; Chaturvedi, Shailesh

    2004-01-01

    The objective of this study was to investigate the relationship between vascular and metabolic characteristics of breast tumours in vivo, using contrast-enhanced dynamic MRI and 2-[ 18 F] fluoro-2-deoxy-d-glucose (FDG) PET imaging. Twenty patients with large or locally advanced primary breast cancers were imaged prior to therapy. MRI data were acquired using a dynamic gradient echo sequence and analysed using two pharmacokinetic models. Static PET data were acquired in 2D mode. A significant association (P<0.05) was observed between the calculated exchange rate constants of both pharmacokinetic models and calculated PET FDG dose uptake ratios (DUR). Statistical analysis showed that the exchange rate constants can explain between 27 and 44% of the variance observed in the PET FDG uptake ratios. A relationship was demonstrated between the vascular and metabolic characteristics of primary breast tumours showing that any assessment of tumour metabolic activity using PET may be controlled at least in part by delivery of uptake agent due to the vascular characteristics of the tumour. MRI and PET provide methods of assessing breast tumour vascularity and metabolism in vivo using the exchange rate constants of dynamic MRI, and DUR of PET, respectively, these measures being related but not equivalent. (orig.)

  19. Admissibility region for rarefaction shock waves in dense gases

    NARCIS (Netherlands)

    Zamfirescu, C.; Guardone, A.; Colonna, P.

    2008-01-01

    In the vapour phase and close to the liquid–vapour saturation curve, fluids made of complex molecules are expected to exhibit a thermodynamic region in which the fundamental derivative of gasdynamic ? is negative. In this region, non-classical gasdynamic phenomena such as rarefaction shock waves are

  20. Maximum intensity of rarefaction shock waves for dense gases

    NARCIS (Netherlands)

    Guardone, A.; Zamfirescu, C.; Colonna, P.

    2009-01-01

    Modern thermodynamic models indicate that fluids consisting of complex molecules may display non-classical gasdynamic phenomena such as rarefaction shock waves (RSWs) in the vapour phase. Since the thermodynamic region in which non-classical phenomena are physically admissible is finite in terms of

  1. Rarefaction Shock Waves in Collisionless Plasma with Electronic Beam

    OpenAIRE

    Gurovich, Victor Ts.; Fel, Leonid G.

    2011-01-01

    We show that an electronic beam passing through the collisionless plasma of the "cold" ions and the "hot" Boltzmann electrons can give rise to the propagation of the supersonic ion-acoustic rarefaction shock waves. These waves are analogous to those predicted by Zeldovich [5] in gasodynamics and complementary to the ion-acoustic compression shock waves in collisionless plasma described by Sagdeev [3].

  2. Shock and Rarefaction Waves in a Heterogeneous Mantle

    Science.gov (United States)

    Jordan, J.; Hesse, M. A.

    2012-12-01

    We explore the effect of heterogeneities on partial melting and melt migration during active upwelling in the Earth's mantle. We have constructed simple, explicit nonlinear models in one dimension to examine heterogeneity and its dynamic affects on porosity, temperature and the magnesium number in a partially molten, porous medium comprised of olivine. The composition of the melt and solid are defined by a closed, binary phase diagram for a simplified, two-component olivine system. The two-component solid solution is represented by a phase loop where concentrations 0 and 1 to correspond to fayalite and forsterite, respectively. For analysis, we examine an advective system with a Riemann initial condition. Chromatographic tools and theory have primarily been used to track large, rare earth elements as tracers. In our case, we employ these theoretical tools to highlight the importance of the magnesium number, enthalpy and overall heterogeneity in the dynamics of melt migration. We calculate the eigenvectors and eigenvalues in the concentration-enthalpy space in order to glean the characteristics of the waves emerging the Riemann step. Analysis on Riemann problems of this nature shows us that the composition-enthalpy waves can be represented by self-similar solutions. The eigenvalues of the composition-enthalpy system represent the characteristic wave propagation speeds of the compositions and enthalpy through the domain. Furthermore, the corresponding eigenvectors are the directions of variation, or ``pathways," in concentration-enthalpy space that the characteristic waves follow. In the two-component system, the Riemann problem yields two waves connected by an intermediate concentration-enthalpy state determined by the intersections of the integral curves of the eigenvectors emanating from both the initial and boundary states. The first wave, ``slow path," and second wave, ``fast path," follow the aformentioned pathways set by the eigenvectors. The slow path wave

  3. Rarefaction effects in gas flows over curved surfaces

    Science.gov (United States)

    Dongari, Nishanth; White, Craig; Scanlon, Thomas J.; Zhang, Yonghao; Reese, Jason M.

    2012-11-01

    The fundamental test case of gas flow between two concentric rotating cylinders is considered in order to investigate rarefaction effects associated with the Knudsen layers over curved surfaces. We carry out direct simulation Monte Carlo simulations covering a wide range of Knudsen numbers and accommodation coefficients, and for various outer-to-inner cylinder radius ratios. Numerical data is compared with classical slip flow theory and a new power-law (PL) wall scaling model. The PL model incorporates Knudsen layer effects in near-wall regions by taking into account the boundary limiting effects on the molecular free paths. The limitations of both theoretical models are explored with respect to rarefaction and curvature effects. Torque and velocity profile comparisons also convey that mere prediction of integral flow parameters does not guarantee the accuracy of a theoretical model, and that it is important to ensure that prediction of the local flowfield is in agreement with simulation data.

  4. Characterization of rarefaction waves in van der Waals fluids

    Science.gov (United States)

    Yuen, Albert; Barnard, John J.

    2015-12-01

    We calculate the isentropic evolution of an instantaneously heated foil, assuming a van der Waals equation of state with the Maxwell construction. The analysis by Yuen and Barnard [Phys. Rev. E 92, 033019 (2015), 10.1103/PhysRevE.92.033019] is extended for the particular case of three degrees of freedom. We assume heating to temperatures in the vicinity of the critical point. The self-similar profiles of the rarefaction waves describing the evolution of the foil display plateaus in density and temperature due to a phase transition from the single-phase to the two-phase regime. The hydrodynamic equations are expressed in a dimensionless form and the solutions form a set of universal curves, depending on a single parameter: the dimensionless initial entropy. We characterize the rarefaction waves by calculating how the plateau length, density, pressure, temperature, velocity, internal energy, and sound speed vary with dimensionless initial entropy.

  5. Uniqueness of rarefaction waves in multidimensional compressible Euler system

    Czech Academy of Sciences Publication Activity Database

    Feireisl, Eduard; Kreml, Ondřej

    2015-01-01

    Roč. 12, č. 3 (2015), s. 489-499 ISSN 0219-8916 R&D Projects: GA ČR GA13-00522S EU Projects: European Commission(XE) 320078 - MATHEF Institutional support: RVO:67985840 Keywords : compressible Euler system * uniqueness * rarefaction wave * Riemann problem Subject RIV: BA - General Mathematics Impact factor: 0.556, year: 2015 http://www.worldscientific.com/doi/abs/10.1142/S0219891615500149

  6. Admissibility region for rarefaction shock waves in dense gases

    OpenAIRE

    Zamfirescu, C.; Guardone, A.; Colonna, P.

    2008-01-01

    In the vapour phase and close to the liquid–vapour saturation curve, fluids made of complex molecules are expected to exhibit a thermodynamic region in which the fundamental derivative of gasdynamic ? is negative. In this region, non-classical gasdynamic phenomena such as rarefaction shock waves are physically admissible, namely they obey the second law of thermodynamics and fulfil the speed-orienting condition for mechanical stability. Previous studies have demonstrated that the thermodynami...

  7. The mean and variance of phylogenetic diversity under rarefaction

    OpenAIRE

    Nipperess, David A.; Matsen, Frederick A.

    2013-01-01

    Phylogenetic diversity (PD) depends on sampling intensity, which complicates the comparison of PD between samples of different depth. One approach to dealing with differing sample depth for a given diversity statistic is to rarefy, which means to take a random subset of a given size of the original sample. Exact analytical formulae for the mean and variance of species richness under rarefaction have existed for some time but no such solution exists for PD. We have derived exact formulae for t...

  8. Relationship between the shoot characteristics and plant resistance to vascular-streak dieback on cocoa

    Directory of Open Access Journals (Sweden)

    Agung Wahyu Soesilo

    2014-12-01

    Full Text Available Vascular-streak dieback (Oncobasidium theobromae is a serious disease on cocoa damaging the vegetative tissue especially on the branches and leaves. This research was aimed to identify the relationship between characteristics of sprouting ability and VSD resistance to confirm the response of cocoa to pruning treatment on VSD control and developing criteria for selection. Trial was carried out at Kaliwining Experimental Station of ICCRI, a VSD-endemic area by using 668 plants of hybrid populayion which were derivated from intercrossing among seven clones performing different response to VSD. The resistance was evaluated by scoring the plant damage with the scale of 0-6 on drought season in the year of 2009 and 2011. The characteristics of sprouting ability was assessed by recording the pruned trees for the variables of the number of re-growth shoot, shoot height, number of new shoot per pruned branches, shoot diameter and number of leaves per shoot. It was analyzed that the variables of the number of shoot per pruned branches, shoot diameter, shoot height and number of leaves per shoot were not significantly correlated to the score of VSD damage. Grouping of the resistance also performed similar results whereas mean of the sprouting variables were not different among group but the percentage of sprouted branches tend to be higher with the higher of the resistance (lower score. This result confirmed any mechanism of tolerance on VSD resistance by accelerating shoot rejuvenation on resistant plant. Key words : vascular-streak diaback, cocoa, resistance, characteristics of sprouting

  9. IMPORTANCE OF KNOWING ANGIOGRAPHIC CHARACTERISTICS OF THE TENSOR FASCIAE LATAE VASCULAR STALK

    Directory of Open Access Journals (Sweden)

    Sladjana Ugrenovic

    2006-07-01

    the most common site for infections in vascular surgery. Good cognition of angiographic characteristics of m. TFL vascular stalk is of great importance for prevention of its necrosis before its usage in surgical purposes.

  10. Reshocks, rarefactions, and the generalized Layzer model for hydrodynamic instabilities

    International Nuclear Information System (INIS)

    Mikaelian, K.O.

    2008-01-01

    We report numerical simulations and analytic modeling of shock tube experiments on Rayleigh-Taylor and Richtmyer-Meshkov instabilities. We examine single interfaces of the type A/B where the incident shock is initiated in A and the transmitted shock proceeds into B. Examples are He/air and air/He. In addition, we study finite-thickness or double-interface A/B/A configurations like air/SF 6 /air gas-curtain experiments. We first consider conventional shock tubes that have a 'fixed' boundary: A solid endwall which reflects the transmitted shock and reshocks the interface(s). Then we focus on new experiments with a 'free' boundary--a membrane disrupted mechanically or by the transmitted shock, sending back a rarefaction towards the interface(s). Complex acceleration histories are achieved, relevant for Inertial Confinement Fusion implosions. We compare our simulation results with a generalized Layzer model for two fluids with time-dependent densities, and derive a new freeze-out condition whereby accelerating and compressive forces cancel each other out. Except for the recently reported failures of the Layzer model, the generalized Layzer model and hydrocode simulations for reshocks and rarefactions agree well with each other, and remain to be verified experimentally

  11. Reshocks, rarefactions, and the generalized Layzer model for hydrodynamic instabilities

    Energy Technology Data Exchange (ETDEWEB)

    Mikaelian, K O

    2008-06-10

    We report numerical simulations and analytic modeling of shock tube experiments on Rayleigh-Taylor and Richtmyer-Meshkov instabilities. We examine single interfaces of the type A/B where the incident shock is initiated in A and the transmitted shock proceeds into B. Examples are He/air and air/He. In addition, we study finite-thickness or double-interface A/B/A configurations like air/SF{sub 6}/air gas-curtain experiments. We first consider conventional shock tubes that have a 'fixed' boundary: A solid endwall which reflects the transmitted shock and reshocks the interface(s). Then we focus on new experiments with a 'free' boundary--a membrane disrupted mechanically or by the transmitted shock, sending back a rarefaction towards the interface(s). Complex acceleration histories are achieved, relevant for Inertial Confinement Fusion implosions. We compare our simulation results with a generalized Layzer model for two fluids with time-dependent densities, and derive a new freeze-out condition whereby accelerating and compressive forces cancel each other out. Except for the recently reported failures of the Layzer model, the generalized Layzer model and hydrocode simulations for reshocks and rarefactions agree well with each other, and remain to be verified experimentally.

  12. Cardiac microvascular rarefaction in hyperthyroidism-induced left ventricle dysfunction.

    Science.gov (United States)

    Freitas, Felipe; Estato, Vanessa; Carvalho, Vinícius Frias; Torres, Rafael Carvalho; Lessa, Marcos Adriano; Tibiriçá, Eduardo

    2013-10-01

    The pathophysiology underlying hyperthyroidism-induced left ventricle (LV) dysfunction and hypertrophy directly involves the heart and indirectly involves the neuroendocrine systems. The effects of hyperthyroidism on the microcirculation are still controversial in experimental models. We investigated the effects of hyperthyroidism on the cardiac function and microcirculation of an experimental rat model. Male Wistar rats (170-250 g) were divided into two groups: the euthyroid group (n = 10), which was treated with 0.9% saline solution, and the hyperthyroid group (n = 10), which was treated with l-thyroxine (600 μg/kg/day, i.p.) during 14 days. An echocardiographic study was performed to evaluate the alterations in cardiac function, structure and geometry. The structural capillary density and the expression of angiotensin II AT1 receptor in the LV were analyzed using histochemistry and immunohistochemistry, respectively. Hyperthyroidism was found to induce profound cardiovascular alterations, such as systolic hypertension, tachycardia, LV dysfunction, cardiac hypertrophy, and myocardial fibrosis. This study demonstrates the existence of structural capillary rarefaction and the down-regulation of the cardiac angiotensin II AT1 receptor in the myocardium of hyperthyroid rats in comparison with euthyroid rats. Microvascular rarefaction may be involved in the pathophysiology of hyperthyroidism-induced cardiovascular alterations. © 2013 John Wiley & Sons Ltd.

  13. Healing characteristics of a new silver-coated, gelatine impregnated vascular prosthesis in the porcine model.

    Science.gov (United States)

    Ueberrueck, T; Meyer, L; Zippel, R; Nestler, G; Wahlers, T; Gastinger, I

    2005-02-01

    To investigate the intraluminal and extraluminal healing behaviour of a new metallic silver coated, gelatine impregnated vascular graft. Comparative animal experimental investigation with randomisation of the animals to control and experimental groups. 24 pigs were assigned to two control and two experimental groups. The prostheses were interposed in the pigs' infrarenal aorta. For the evaluation, macroscopic, histological and immunohistochemical criteria were applied. The macroscopic evaluation after explantation of the prosthesis revealed similar healing characteristics in the control and experimental groups. The microscopic determination of neo-intimal thickness showed no significant differences between the groups; nor did the immunohistochemical investigations show any significant difference between the control group and the silver-coated prosthesis group. No disadvantage of the silver coating in terms of healing and graft patency was found. A possible advantage in terms of the antibacterial effect of the silver coating must be investigated in the clinical setting.

  14. The study of distribution characteristics of vascular and naturalized plants in Dokdo, South Korea

    Directory of Open Access Journals (Sweden)

    Su-Young Jung

    2014-06-01

    Full Text Available This study was performed to investigate the distribution of vascular plants and the characteristics of naturalized plants in Dokdo Island, South Korea. The survey was conducted a total of 5 times from June 2012 to September 2013. The number of plants confirmed in this study was 60 taxa in total: 29 families, 49 genera, 55 species, 2 subspecies and 3 varieties. To classify them by regional groups, 53 taxa were confirmed in the Dongdo and 38 taxa were confirmed in the Seodo. Among them, the distribution of Stellaria neglecta Weihe and Puccinellia nipponica Ohwi was first discovered in this study. The naturalized plants distributed in Dokdo was 7 taxa: Chenopodium album L., Sonchus asper (L. Hill, Sonchus oleraceus L., Ipomoea purpurea Roth, Brassica juncea (L. Czern., etc. Overall, concerns over the naturalized plants in Dokdo are high regardless of the scale of their distribution and the appearance frequency.

  15. Characteristics of patients presenting to the vascular emergency department of a tertiary care hospital: a 2-year study

    Directory of Open Access Journals (Sweden)

    Kotsikoris Ioannis

    2011-11-01

    Full Text Available Abstract Background The structure of health care in Greece is receiving increased attention to improve its cost-effectiveness. We sought to examine the epidemiological characteristics of patients presenting to the vascular emergency department of a Greek tertiary care hospital during a 2-year period. We studied all patients presenting to the emergency department of vascular surgery at Red Cross Hospital, Athens, Greece between 1st January 2009 and 31st December 2010. Results Overall, 2452 (49.4% out of 4961 patients suffered from pathologies that should have been treated in primary health care. Only 2509 (50.6% needed vascular surgical intervention. Conclusions The emergency department of vascular surgery in a Greek tertiary care hospital has to treat a remarkably high percentage of patients suitable for the primary health care level. These results suggest that an improvement in the structure of health care is needed in Greece.

  16. Cardiovascular risk factors cause premature rarefaction of the collateral circulation and greater ischemic tissue injury.

    Science.gov (United States)

    Moore, Scott M; Zhang, Hua; Maeda, Nobuyo; Doerschuk, Claire M; Faber, James E

    2015-07-01

    Collaterals lessen tissue injury in occlusive disease. However, aging causes progressive decline in their number and smaller diameters in those that remain (collateral rarefaction), beginning at 16 months of age in mice (i.e., middle age), and worse ischemic injury-effects that are accelerated in even 3-month-old eNOS(-/-) mice. These findings have found indirect support in recent human studies. We sought to determine whether other cardiovascular risk factors (CVRFs) associated with endothelial dysfunction cause collateral rarefaction, investigate possible mechanisms, and test strategies for prevention. Mice with nine different models of CVRFs of 4-12 months of age were assessed for number and diameter of native collaterals in skeletal muscle and brain and for collateral-dependent perfusion and ischemic injury after arterial occlusion. Hypertension caused collateral rarefaction whose severity increased with duration and level of hypertension, accompanied by greater hindlimb ischemia and cerebral infarct volume. Chronic treatment of wild-type mice with L-N (G)-nitro-arginine methylester caused similar rarefaction and worse ischemic injury which were not prevented by lowering arterial pressure with hydralazine. Metabolic syndrome, hypercholesterolemia, diabetes mellitus, and obesity also caused collateral rarefaction. Neither chronic statin treatment nor exercise training lessened hypertension-induced rarefaction. Chronic CVRF presence caused collateral rarefaction and worse ischemic injury, even at relatively young ages. Rarefaction was associated with increased proliferation rate of collateral endothelial cells, effects that may promote accelerated endothelial cell senescence.

  17. Urban ecological characteristics and vascular wall flora on the Anatolian side of Istanbul, Turkey

    Directory of Open Access Journals (Sweden)

    Volkan Altay

    2010-11-01

    Full Text Available The aim of this study is to specify the urban ecologic characteristics of Istanbul and to show their reflection to the vascular wall flora of the Anatolian side, which is a distinctive wall habitat. Plants samples of the urban habitat were collected from the top and vertical surfaces of walls during 2005-2007. A total of 101 taxa (81 species, 13 subspecies and 7 varieties belonging to 74 genera and 33 families were recorded. It was determined that 80 species were Dicotyledones while 1 was Monocotyledone. The families with the largest number of taxa were Asteraceae (18 species, 22.22%, Poaceae (8 species, 9.87%, Lamiaceae and Brassicaceae (5 species, 6.17%, and Polygonaceae and Scrophulariaceae (4 species, 4.93%. The most common plant species on walls were Parietaria judaica L. (Urticaceae, Stellaria media (L. Vill. subsp. media (Caryophyllaceae, and Mercurialis annua L. (Euphorbiaceae. The percentage of phytogeographical elements among the recorded taxa varied as follows: Euro-Siberian (6 taxa, 7.41%, Mediterranean (11 taxa, 13.58%, E. Mediterranian (2 taxa, 2.47%, Irano-Turanian (1 taxon, 1.23% and unknown (61 taxa, 75.31%. It was found that 6 taxa (7.41% were cosmopolitan, 12 (14.82% were widespread while 1 (1.23% was endemic. The results were compared with some other European wall floras and some similarities and dissimilarities were noted.

  18. Rarefaction shock waves and Hugoniot curve in the presence of free and trapped particles

    International Nuclear Information System (INIS)

    Niknam, A. R.; Hashemzadeh, M.; Shokri, B.; Rouhani, M. R.

    2009-01-01

    The effects of the relativistic ponderomotive force and trapped particles in the presence of ponderomotive force on the rarefaction shock waves are investigated. The ponderomotive force alters the electron density distribution. This force and relativistic mass affect the plasma frequency. These physical parameters modify the total pressure and the existence condition of the rarefaction shock wave. Furthermore, the trapping of particles by the high frequency electromagnetic field considerably changes the existence condition of the rarefaction shock wave. The total pressure and Hugoniot curve are obtained by considering the relativistic ponderomotive force and trapped particles.

  19. Rarefaction shock waves and Hugoniot curve in the presence of free and trapped particles

    Science.gov (United States)

    Niknam, A. R.; Hashemzadeh, M.; Shokri, B.; Rouhani, M. R.

    2009-12-01

    The effects of the relativistic ponderomotive force and trapped particles in the presence of ponderomotive force on the rarefaction shock waves are investigated. The ponderomotive force alters the electron density distribution. This force and relativistic mass affect the plasma frequency. These physical parameters modify the total pressure and the existence condition of the rarefaction shock wave. Furthermore, the trapping of particles by the high frequency electromagnetic field considerably changes the existence condition of the rarefaction shock wave. The total pressure and Hugoniot curve are obtained by considering the relativistic ponderomotive force and trapped particles.

  20. Vascular leiomyoma of the oral cavity. Clinical, histopathological and immunohistochemical characteristics. Presentation of five cases and review of the literature.

    Science.gov (United States)

    Gaitan Cepeda, Luis Alberto; Quezada Rivera, Daniel; Tenorio Rocha, Fernando; Leyva Huerta, Elba Rosa; Mendez Sánchez, Edgar Ramiro

    2008-08-01

    Leiomyoma, a benign neoplasia arising from smooth muscle is an uncommon neoplasia of the oral cavity. The most common histological subtype in the oral cavity is the vascular one. To supplement information on vascular leiomyoma of the oral cavity (VLOC), we present cases of VLOC describing their clinical, histological, and immunohistochemical characteristics. Case reports. Five cases of VLOC (3 females; 2 males) from the Clinical and Experimental Pathology Laboratory, Dental School, National Autonomous University of México, are included. The most frequent clinical characteristic of VLOC was a single, asymptomatic, slow growing nodule. The age average of the cases was 40.6, however 3 out of our 5 cases were < or = 40 years old at the moment of their diagnosis. The lesions were composed of fusiform cells arranged in bundles or fascicles. The neoplastic cells were characterized by eosinophilic cytoplasm and tapered nuclei. The presence of vascular spaces was prominent in all cases. The immunocharacteristics of VLOC neoplastic cells were: alpha smooth muscle (+); vimentin (+), desmin (+), CD34 (-) and S-100 protein (-). The endothelial cells of vascular spaces were CD34 (+). Differential diagnosis of VLOC with fusocellular neoplasm is discussed.

  1. Ultrastructural characteristics of the vascular wall components of ruptured atherosclerotic abdominal aortic aneurysm

    Directory of Open Access Journals (Sweden)

    Tanasković Irena

    2013-01-01

    Full Text Available The aim of this study was to determine the ultrastructural characteristics of cell populations and extracellular matrix components in the wall of ruptured atherosclerotic abdominal aortic aneurysm (AAA. We analyzed 20 samples of ruptured AAA. For orientation to the light microscopy, we used routine histochemical techniques by standard procedures. For ultrastructural analysis, we applied transmission electron microscopy (TEM. Our results have shown that ruptured AAA is characterized by the remains of an advanced atherosclerotic lesion in the intima followed by a complete absence of endothelial cells, the disruption of basal membrane and disruption of internal elastic lamina. On plaque margins as well as in the inner media we observed smooth muscle cells (SMCs that posses a euchromatic nucleus, a well-developed granulated endoplasmic reticulum around the nucleus and reduced myofilaments. The remains of the ruptured lipid core were acellular in all samples; however, on the lateral sides of ruptured plaque we observed a presence of two types of foam cells (FCs, spindle- and star-shaped. Fusiform FCs possess a well-differentiated basal lamina, caveolae and electron dense bodies, followed by a small number of lipid droplets in the cytoplasm. Star-shaped FCs contain a large number of lipid droplets and do not possess basal lamina. On the inner margins of the plaque, we observed a large number of cells undergoing apoptosis and necrosis, extracellular lipid droplets as well as a large number of lymphocytes. The media was thinned out with disorganized elastic lamellas, while the adventitia exhibited leukocyte infiltration. The presented results suggest that atherosclerotic plaque in ruptured AAA contains vascular SMC synthetic phenotype and two different types of FCs: some were derived from monocyte/macrophage lineage, while others were derived from SMCs of synthetic phenotype. The striking plaque hypocellularity was the result of apoptosis and necrosis

  2. Wave Refraction During the May 2002 Rarefaction Event

    Science.gov (United States)

    Smith, C. W.; Mullan, D. J.; Ness, N. F.; Skoug, R. M.

    2002-12-01

    In previous work [Smith et al., 2001] we examined IMF wave refraction during the May 1999 rarefaction interval known as ``The Day The Solar Wind Disappeared.'' On that day, Alfvén speeds remained elevated over an extended region. Analysis of the recorded ACE fields and plasma data revealed depressed magnetic fluctuation levels, reduced compression in the fluctuations, and a reduced wave-like component within the region of elevated Alfvén speed, all consistent with wave refraction. The May 2002 event provides a third such period (the second identified event occured 2 weeks prior to the May 1999 period) and it again demonstrates properties which are consistent with refraction. Smith, C.~W., D.~J. Mullan, N.~F. Ness, R.~M. Skoug, and J.~Steinberg, Day the solar wind almost disappeared: Magnetic field fluctuations, wave refraction and dissipation, J. Geophys. Res., A106, 18,625--18,634, 2001. Efforts at the Bartol Research Institute were supported by CIT subcontract PC251439 under NASA grant NAG5-6912 for support of the ACE magnetic field experiment and by the NASA Delaware Space College Grant. Work at Los Alamos was performed under the auspices of the U.S. Department of Energy with financial support from the NASA ACE program.

  3. Interacting wave fronts and rarefaction waves in a second order model of nonlinear thermoviscous fluids : Interacting fronts and rarefaction waves

    DEFF Research Database (Denmark)

    Rasmussen, Anders Rønne; Sørensen, Mads Peter; Gaididei, Yuri Borisovich

    2011-01-01

    A wave equation including nonlinear terms up to the second order for a thermoviscous Newtonian fluid is proposed. In the lossless case this equation results from an expansion to third order of the Lagrangian for the fundamental non-dissipative fluid dynamical equations. Thus it preserves the Hami...... is proposed. The dynamics of the rarefaction wave is approximated by a collective coordinate approach in the energy balance equation. © 2010 Springer Science+Business Media B.V.......A wave equation including nonlinear terms up to the second order for a thermoviscous Newtonian fluid is proposed. In the lossless case this equation results from an expansion to third order of the Lagrangian for the fundamental non-dissipative fluid dynamical equations. Thus it preserves...... the Hamiltonian structure, in contrast to the Kuznetsov equation, a model often used in nonlinear acoustics. An exact traveling wave front solution is derived from a generalized traveling wave assumption for the velocity potential. Numerical studies of the evolution of a number of arbitrary initial conditions...

  4. Linear perturbation growth at the trailing edge of a rarefaction wave

    International Nuclear Information System (INIS)

    Wouchuk, J.G.; Carretero, R.

    2003-01-01

    An analytic model for the perturbation growth inside a rarefaction wave is presented. The objective of the work is to calculate the growth of the perturbations at the trailing edge of a simple expanding wave in planar geometry. Previous numerical and analytical works have shown that the ripples at the rarefaction tail exhibit linear growth asymptotically in time [Yang et al., Phys. Fluids 6, 1856 (1994), A. Velikovich and L. Phillips, ibid. 8, 1107 (1996)]. However, closed expressions for the asymptotic value of the perturbed velocity of the trailing edge have not been reported before, except for very weak rarefactions. Explicit analytic solutions for the perturbations growing at the rarefaction trailing edge as a function of time and also for the asymptotic perturbed velocity are given, for fluids with γ<3. The limits of weak and strong rarefactions are considered and the corresponding scaling laws are given. A semi-qualitative discussion of the late time linear growth at the trailing edge ripple is presented and it is seen that the lateral mass flow induced by the sound wave fluctuations is solely responsible for that behavior. Only the rarefactions generated after the interaction of a shock wave with a contact discontinuity are considered

  5. Circulating IGF-1 deficiency exacerbates hypertension-induced microvascular rarefaction in the mouse hippocampus and retrosplenial cortex: implications for cerebromicrovascular and brain aging.

    Science.gov (United States)

    Tarantini, Stefano; Tucsek, Zsuzsanna; Valcarcel-Ares, M Noa; Toth, Peter; Gautam, Tripti; Giles, Cory B; Ballabh, Praveen; Wei, Jeanne Y; Wren, Jonathan D; Ashpole, Nicole M; Sonntag, William E; Ungvari, Zoltan; Csiszar, Anna

    2016-08-01

    Strong epidemiological and experimental evidence indicate that both age and hypertension lead to significant functional and structural impairment of the cerebral microcirculation, predisposing to the development of vascular cognitive impairment (VCI) and Alzheimer's disease. Preclinical studies establish a causal link between cognitive decline and microvascular rarefaction in the hippocampus, an area of brain important for learning and memory. Age-related decline in circulating IGF-1 levels results in functional impairment of the cerebral microvessels; however, the mechanistic role of IGF-1 deficiency in impaired hippocampal microvascularization remains elusive. The present study was designed to characterize the additive/synergistic effects of IGF-1 deficiency and hypertension on microvascular density and expression of genes involved in angiogenesis and microvascular regression in the hippocampus. To achieve that goal, we induced hypertension in control and IGF-1 deficient mice (Igf1 f/f  + TBG-Cre-AAV8) by chronic infusion of angiotensin II. We found that circulating IGF-1 deficiency is associated with decreased microvascular density and exacerbates hypertension-induced microvascular rarefaction both in the hippocampus and the neocortex. The anti-angiogenic hippocampal gene expression signature observed in hypertensive IGF-1 deficient mice in the present study provides important clues for subsequent studies to elucidate mechanisms by which hypertension may contribute to the pathogenesis and clinical manifestation of VCI. In conclusion, adult-onset, isolated endocrine IGF-1 deficiency exerts deleterious effects on the cerebral microcirculation, leading to a significant decline in cortical and hippocampal capillarity and exacerbating hypertension-induced cerebromicrovascular rarefaction. The morphological impairment of the cerebral microvasculature induced by IGF-1 deficiency and hypertension reported here, in combination with neurovascular uncoupling, increased

  6. Intravenous nitroglycerin as an experimental model of vascular headache. Basic characteristics

    DEFF Research Database (Denmark)

    Iversen, Helle Klingenberg; Olesen, J; Tfelt-Hansen, P

    1989-01-01

    To develop a reliable experimental model of vascular headache, we studied the dose-response relationship between headache and i.v. nitroglycerin (NTG) in 10 healthy subjects. NTG was infused intravenously over periods of 10 min separated by wash-out periods. Doses of 0.25, 0.50, 1.00 and 2......) at various doses and declined rapidly after NTG discontinuation. Wash-out periods of 10-20 min were sufficient. The reproducibility of headache intensity and character was satisfactory in the retest experiment. There were no unpleasant side effects and no visible flushing. Thus blindness was maintained. I...

  7. Compressive and rarefactive solitary waves in nonthermal two-component plasmas

    International Nuclear Information System (INIS)

    Verheest, Frank; Hellberg, Manfred A.

    2010-01-01

    Using a Sagdeev pseudopotential formalism where nonlinear structures are stationary in a comoving frame, large ion-acoustic solitary waves and double layers have been studied in plasmas with positive ions and nonthermal electrons. The velocity range of positive, compressive solitary waves is limited by the ion density reaching infinite compression, whereas negative, rarefactive solitary waves and double layers can exist when the electron nonthermality exceeds a certain minimum. There are even regions of coexistence, the limits of which can be elucidated by considering the properties of the special Sagdeev pseudopotential at the acoustic speed. In particular, when the compositional parameters and Mach numbers admit only compressive or rarefactive solitary structures, these have to be superacoustic, their amplitude vanishing at the acoustic speed. When both compressive and rarefactive modes can occur, one of them is Korteweg-de Vries (KdV)-like, the other having a non-KdV character, with a finite amplitude at the acoustic speed.

  8. Algorithmic Foundation of Spectral Rarefaction for Measuring Satellite Imagery Heterogeneity at Multiple Spatial Scales

    Science.gov (United States)

    Rocchini, Duccio

    2009-01-01

    Measuring heterogeneity in satellite imagery is an important task to deal with. Most measures of spectral diversity have been based on Shannon Information theory. However, this approach does not inherently address different scales, ranging from local (hereafter referred to alpha diversity) to global scales (gamma diversity). The aim of this paper is to propose a method for measuring spectral heterogeneity at multiple scales based on rarefaction curves. An algorithmic solution of rarefaction applied to image pixel values (Digital Numbers, DNs) is provided and discussed. PMID:22389600

  9. Stability of Planar Rarefaction Wave to 3D Full Compressible Navier-Stokes Equations

    Science.gov (United States)

    Li, Lin-an; Wang, Teng; Wang, Yi

    2018-05-01

    We prove time-asymptotic stability toward the planar rarefaction wave for the three-dimensional full, compressible Navier-Stokes equations with the heat-conductivities in an infinite long flat nozzle domain {R × T^2} . Compared with one-dimensional case, the proof here is based on our new observations on the cancellations on the flux terms and viscous terms due to the underlying wave structures, which are crucial for overcoming the difficulties due to the wave propagation in the transverse directions x 2 and x 3 and its interactions with the planar rarefaction wave in x 1 direction.

  10. Identification of a characteristic vascular belt zone in human colorectal cancer.

    Directory of Open Access Journals (Sweden)

    Jakob Nikolas Kather

    Full Text Available Intra-tumoral blood vessels are of supreme importance for tumor growth, metastasis and therapy. Yet, little is known about spatial distribution patterns of these vessels. Most experimental or theoretical tumor models implicitly assume that blood vessels are equally abundant in different parts of the tumor, which has far-reaching implications for chemotherapy and tumor metabolism. In contrast, based on histological observations, we hypothesized that blood vessels follow specific spatial distribution patterns in colorectal cancer tissue. We developed and applied a novel computational approach to identify spatial patterns of angiogenesis in histological whole-slide images of human colorectal cancer.In 33 of 34 (97% colorectal cancer primary tumors blood vessels were significantly aggregated in a sharply limited belt-like zone at the interface of tumor tissue to the intestinal lumen. In contrast, in 11 of 11 (100% colorectal cancer liver metastases, a similar hypervascularized zone could be found at the boundary to surrounding liver tissue. Also, in an independent validation cohort, we found this vascular belt zone: 22 of 23 (96% samples of primary tumors and 15 of 16 (94% samples of liver metastases exhibited the above-mentioned spatial distribution.We report consistent spatial patterns of tumor vascularization that may have far-reaching implications for models of drug distribution, tumor metabolism and tumor growth: luminal hypervascularization in colorectal cancer primary tumors is a previously overlooked feature of cancer tissue. In colorectal cancer liver metastases, we describe a corresponding pattern at the invasive margin. These findings add another puzzle piece to the complex concept of tumor heterogeneity.

  11. Fissioning of nonlinear ion-acoustic rarefactive pulse in a homogeneous quiescent plasma

    International Nuclear Information System (INIS)

    Saxena, Y.C.; Mattoo, S.K.; Sekar, A.N.

    1982-01-01

    A finite amplitude rarefactive ion-acoustic wave is observed to fission resulting in two minima. After fissioning the two minima travel at different speeds, one at 0.8 Csub(s) and the other at 1.2 Csub(s), where Csub(s) is the ion-acoustic speed. (author)

  12. Can rarefaction be used to estimate song repertoire size in birds?

    Directory of Open Access Journals (Sweden)

    Kathleen R. PESHEK, Daniel T. BLUMSTEIN

    2011-06-01

    Full Text Available Song repertoire size is the number of distinct syllables, phrases, or song types produced by an individual or population. Repertoire size estimation is particularly difficult for species that produce highly variable songs and those that produce many song types. Estimating repertoire size is important for ecological and evolutionary studies of speciation, studies of sexual selection, as well as studies of how species may adapt their songs to various acoustic environments. There are several methods to estimate repertoire size, however prior studies discovered that all but a full numerical count of song types might have substantial inaccuracies associated with them. We evaluated a somewhat novel approach to estimate repertoire size—rarefaction; a technique ecologists use to measure species diversity on individual and population levels. Using the syllables within American robins’ Turdus migratorius repertoire, we compared the most commonly used techniques of estimating repertoires to the results of a rarefaction analysis. American robins have elaborate and unique songs with few syllables shared between individuals, and there is no evidence that robins mimic their neighbors. Thus, they are an ideal system in which to compare techniques. We found that the rarefaction technique results resembled that of the numerical count, and were better than two alternative methods (behavioral accumulation curves, and capture-recapture to estimate syllable repertoire size. Future estimates of repertoire size, particularly in vocally complex species, may benefit from using rarefaction techniques when numerical counts are unable to be performed [Current Zoology 57 (3: 300–306, 2011].

  13. Statistical characteristics of surface integrity by fiber laser cutting of Nitinol vascular stents

    International Nuclear Information System (INIS)

    Fu, C.H.; Liu, J.F.; Guo, Andrew

    2015-01-01

    Graphical abstract: - Highlights: • Precision kerf with tight tolerance of Nitinol stents can be cut by fiber laser. • No HAZ in the subsurface was detected due to large grain size. • Recast layer has lower hardness than the bulk. • Laser cutting speed has a higher influence on surface integrity than laser power. - Abstract: Nitinol alloys have been widely used in manufacturing of vascular stents due to the outstanding properties such as superelasticity, shape memory, and superior biocompatibility. Laser cutting is the dominant process for manufacturing Nitinol stents. Conventional laser cutting usually produces unsatisfactory surface integrity which has a significant detrimental impact on stent performance. Emerging as a competitive process, fiber laser with high beam quality is expected to produce much less thermal damage such as striation, dross, heat affected zone (HAZ), and recast layer. To understand the process capability of fiber laser cutting of Nitinol alloy, a design-of-experiment based laser cutting experiment was performed. The kerf geometry, roughness, topography, microstructure, and hardness were studied to better understand the nature of the HAZ and recast layer in fiber laser cutting. Moreover, effect size analysis was conducted to investigate the relationship between surface integrity and process parameters.

  14. Statistical characteristics of surface integrity by fiber laser cutting of Nitinol vascular stents

    Energy Technology Data Exchange (ETDEWEB)

    Fu, C.H., E-mail: cfu5@crimson.ua.edu [Dept of Mechanical Engineering, The University of Alabama, Tuscaloosa, AL 35487 (United States); Liu, J.F. [Dept of Mechanical Engineering, The University of Alabama, Tuscaloosa, AL 35487 (United States); Guo, Andrew [Dept of Mechanical Engineering, The University of Alabama, Tuscaloosa, AL 35487 (United States); College of Arts and Science, Vanderbilt University, Nashville, TN 37235 (United States)

    2015-10-30

    Graphical abstract: - Highlights: • Precision kerf with tight tolerance of Nitinol stents can be cut by fiber laser. • No HAZ in the subsurface was detected due to large grain size. • Recast layer has lower hardness than the bulk. • Laser cutting speed has a higher influence on surface integrity than laser power. - Abstract: Nitinol alloys have been widely used in manufacturing of vascular stents due to the outstanding properties such as superelasticity, shape memory, and superior biocompatibility. Laser cutting is the dominant process for manufacturing Nitinol stents. Conventional laser cutting usually produces unsatisfactory surface integrity which has a significant detrimental impact on stent performance. Emerging as a competitive process, fiber laser with high beam quality is expected to produce much less thermal damage such as striation, dross, heat affected zone (HAZ), and recast layer. To understand the process capability of fiber laser cutting of Nitinol alloy, a design-of-experiment based laser cutting experiment was performed. The kerf geometry, roughness, topography, microstructure, and hardness were studied to better understand the nature of the HAZ and recast layer in fiber laser cutting. Moreover, effect size analysis was conducted to investigate the relationship between surface integrity and process parameters.

  15. Uterine and placenta characteristics during early vascular development in the pig from day 22 to 42 of gestation.

    Science.gov (United States)

    Wright, Elane C; Miles, Jeremy R; Lents, Clay A; Rempel, Lea A

    2016-01-01

    Insufficient placenta development is one of the primary causes of fetal death and reduced fetal growth after 35 days of gestation. Between day 22 and 42 the placenta consists of a central highly vascular placenta (HVP), adjacent to the fetus, a less vascular placenta (LVP), on either side of the fetus, and necrotic tips (NT). The objective of this study was to comprehensively evaluate uterine-placenta characteristics during early gestation in the gilt and determine time points and physiological changes. Gilts (n=25) were artificially inseminated at first detection of estrus (day 0) and 24h later, and harvested at 22, 27, 32, 37 or 42 days of gestation. Litter size, 12.1±3.4, was similar for all days of gestation. Fetal and placenta weight increased with day of gestation. The greatest increase in placenta weight occurred between 37 and 42 days of gestation. The LVP zones had no measurable fold formation until day 27. Necrotic tips became apparent after 27 days of gestation. Unoccupied areas of the uterus developed folds with changes in endometrial cell size and morphology from day 32 to 42 of gestation. Limited changes occurred in either fetal growth or placenta weight from day 27 through 32 of gestation; however, significant morphological changes occur at the maternal-fetal interface, demonstrating the dynamic architecture of the developing porcine placenta during early gestation. This work establishes fundamental time points in placenta development corresponding to fetal growth and microfold formation that may influence fetal growth and impact fetal survival. Published by Elsevier B.V.

  16. [Head and neck paragangliomas. Embryological origin and anatomical characteristics: topographic distribution and vascularization pattern].

    Science.gov (United States)

    Carretero González, José; Blanco Pérez, Pedro; Vázquez Osorio, María Teresa; Benito González, Fernando; Sañudo Tejedo, José Ramón

    2009-02-01

    Paragangliomas are tumors that arise in the extraadrenal paraganglia and result from migration of neural crest cells during embryonic development. Based on their anatomical distribution, innervation and microscopic structure, these tumors can be classified into interrelated families: branchiomeric paraganglia (related to the branchial clefts and arches), intravagal, aortic-sympathetic and visceral-autonomic. Head and neck paragangliomas belong mainly to the first two of these families. The present article is divided into two parts. The first part reviews the embryological origin of these tumors. Special emphasis is placed on the process of neurulation or neural tube formation, neurosegmentation (with a summary of the mechanisms involved in the initial segmentation of the neural tube and of the hindbrain and spinal medulla), and the development of the sensory placodes and secondary inductions in the cranial region. Subsequently, the neural crest is analyzed, with special attention paid to the cranial neural crest. The embryonogenesis of paragangliomas is also described. The second part describes the topographical distribution of head and neck paragangliomas according to their localization: jugulotympanic, orbit, intercarotid, subclavian and laryngeal. The embryonogenesis and most important anatomical characteristics are described for each type.

  17. [Clinical characteristic of patients with acute kidney injury complicated severe cardio-vascular diseases].

    Science.gov (United States)

    Wróbel, Paweł; Wyrwicz-Zielińska, Grażyna; Krzysztonek-Weber, Izabela; Sułowicz, Władysław

    2016-01-01

    Patients with cardiovascular diseases are a group of increased risk of acute kidney injury (AKI). Mortality in this group of patients with AKI, especially treated in intensive care units, is very high. The aim of this study was to evaluate the clinical characteristic of patients with AKI complicated severe cardiovascular diseases. Retrospective evaluation of 246 questionnaire of patients with AKI in the course of severe cardiovascular diseases treated in the wards of nephrological profile from the malopolska and podkarpackie voivodships in the years 2000-2011 was performed. The group of patients consisted of 157 men and 89 women, with mean age 67.9 ± 14.8 years. The most common cause of AKI were: acute decompensated heart failure--24 (9.8%), chronic decompensated heart failure--94 (38.2%), cardiac arrest--29 (11.8%), myocardial infarction--48 (19.5%), CABG--12 (4.9%), cardiac valve implantation--14 (5.7), heart transplantation--4 (1.6%) and aortic aneurysm--21 (8.5%). Age distribution of patients with AKI revealed that most numerous group had 71-80 years. The most of patients (95.9%) with AKI were treated with hemodialysis. The mortality rate in the study group was very high (69.5%). Recovery of renal function was observed in 39 (27.3%) of patients. Signs of kidney disease before AKI was noted in 116 (47.2%) of patients. Patients with severe cardiovascular complications and AKI had high mortality rate instead of performed hemodialysis treatment.

  18. Rarefaction and compression waves of the first sound in superfluid He-II

    International Nuclear Information System (INIS)

    Efimov, V.F.; Kolmakov, G.V.; Lebedeva, E.V.; Mezhov-Deglin, L.P.; Trusov, A.B.

    1999-01-01

    The evolution of the form of the first sound waves, excited by the pulse heater in the superfluid He-II with increase in the thermal pulse Q-capacity, is studied. Propagation of the first sound rarefaction wave (heating wave), subsequent transformation of the rarefaction wave into the compression wave and further into the compression shock wave with Q growth are observed in the fluid, compressed up to 13.3 atm., i.e. it is possible to judge about the change in the heat transfer conditions at the solid body - He-II interface by the change in the sound wave form. It is established that heat expansion of the He-I normal fluid layer, originating at the interface between He-II and the heater by the Q-capacity exceeding certain critical one, is the basic cause of the compression waves excitation in He-II by the pressures of P ≥ 1 atm [ru

  19. Experiments on ion-acoustic rarefactive solitons in a multi-component plasma with negative ions

    International Nuclear Information System (INIS)

    Nakamura, Y.; Ferreira, J.L.; Ludwig, G.O.

    1987-09-01

    Ion-acoustic solitons in a three-component plasma which consists of electrons, positive and negative ions have been investigated experimentally. When the concentration of negative ions is smaller than a certain value, positive or compressive solitons are observed. At the critical concentration, a broad pulse of small but finite amplitude propagates without changing its shape. When the concentration is larger than this value, negative or rarefactive solitons are excited. The velocity and the width of these solitons are measured and compared with predictions of the Korteweg- de Vries equation which takes the negative ions and the ion temperature into consideration. Head-ion and over-taking collisions of the rarefactive solitons have been observed to show that the solitons are not affected by these collisions. (author) [pt

  20. Partial Rarefaction as Way to Reduce Distortion Curve of double-glazed unit

    Science.gov (United States)

    Plotnikov, Alexander

    2017-10-01

    Use of Insulated Glass Units (IGU) as glazing on building façades causes optical distortions of mirrored images of neighboring buildings in glazed surfaces. Optical distortions are caused by varying distances between glass panes in IGUs as a result of climate factors. This paper examines available engineering solutions that reduce such distortions: use of more rigid outer glasses, encasing the building in a shell of single glass panes, known as the ‘double façade’, and use of vacuum IGUs. A new way is proposed to reduce optical distortions by installing additional pointed or linear supports and creating pre-stress with partial rarefaction inside the IGU. Overpressure that can cause IGU expansion and glass deformation was calculated. In the urban environment of Moscow, reduction of air pressure with simultaneous increase of air pressure inside the IGU during summer heat waves can be as high as 5%, and this figure determines the level of rarefaction.

  1. Observation of ion-acoustic rarefaction solitons in a multicomponent plasma with negative ions

    International Nuclear Information System (INIS)

    Ludwig, G.O.; Ferreira, J.L.; Nakamura, Y.

    1984-01-01

    The propagation of ion-acoustic solitons in a plasma with negative ions has been observed. For sufficiently large concentration of negative ions, applied rarefactive (negative) voltage pulses break up into solitons, whereas compressive pulses evolve into wave trains, with exactly the opposite behavior as that for a plasma composed only of positive ions. There is a critical value of the negative-ion concentration for which a finite-amplitude pulse propagates without steepening

  2. Relationships between spectral and bird species rarefaction curves in a brutian pine forest ecosystem

    OpenAIRE

    Özdemir, İbrahim; Mert, Ahmet; Özkan, Ulaş Yunus; Aksan, Şengül; Ünal, Yasin

    2017-01-01

    This study aimed at determining the relations betweenspectral and bird species rarefaction curves in a brutian pine forest ecosystemlocated in the Fethiye region, Turkey. Bird species were counted by fieldworkin 40 sample plots with 0.81 ha (90 x 90 m). The NDVITOA values of pixelsbelonging to each plot (pixel numbers are 36, 81 and 324 for Aster, SPOT andRapidEye, respectively) were calculated. Spectral and bird species rarefactioncurves were formed by means of EstimatesS software. The relat...

  3. Rarefaction acceleration of ultrarelativistic magnetized jets in gamma-ray burst sources

    Science.gov (United States)

    Komissarov, Serguei S.; Vlahakis, Nektarios; Königl, Arieh

    2010-09-01

    When a magnetically dominated superfast-magnetosonic long/soft gamma-ray burst (GRB) jet leaves the progenitor star, the external pressure support will drop and the jet may enter the regime of ballistic expansion, during which additional magnetic acceleration becomes ineffective. However, recent numerical simulations by Tchekhovskoy et al. have suggested that the transition to this regime is accompanied by a spurt of acceleration. We confirm this finding numerically and attribute the acceleration to a sideways expansion of the jet, associated with a strong magnetosonic rarefaction wave that is driven into the jet when it loses pressure support, which induces a conversion of magnetic energy into kinetic energy of bulk motion. This mechanism, which we dub rarefaction acceleration, can only operate in a relativistic outflow because in this case the total energy can still be dominated by the magnetic component even in the superfast-magnetosonic regime. We analyse this process using the equations of relativistic magnetohydrodynamics and demonstrate that it is more efficient at converting internal energy into kinetic energy when the flow is magnetized than in a purely hydrodynamic outflow, as was found numerically by Mizuno et al. We show that, just as in the case of the magnetic acceleration of a collimating jet that is confined by an external pressure distribution - the collimation-acceleration mechanism - the rarefaction-acceleration process in a magnetized jet is a consequence of the fact that the separation between neighbouring magnetic flux surfaces increases faster than their cylindrical radius. However, whereas in the case of effective collimation-acceleration the product of the jet opening angle and its Lorentz factor does not exceed ~1, the addition of the rarefaction-acceleration mechanism makes it possible for this product to become >>1, in agreement with the inference from late-time panchromatic breaks in the afterglow light curves of long/soft GRBs.

  4. Anomalous width variation of rarefactive ion acoustic solitary waves in the context of auroral plasmas

    Directory of Open Access Journals (Sweden)

    S. S. Ghosh

    2004-01-01

    Full Text Available The presence of dynamic, large amplitude solitary waves in the auroral regions of space is well known. Since their velocities are of the order of the ion acoustic speed, they may well be considered as being generated from the nonlinear evolution of ion acoustic waves. However, they do not show the expected width-amplitude correlation for K-dV solitons. Recent POLAR observations have actually revealed that the low altitude rarefactive ion acoustic solitary waves are associated with an increase in the width with increasing amplitude. This indicates that a weakly nonlinear theory is not appropriate to describe the solitary structures in the auroral regions. In the present work, a fully nonlinear analysis based on Sagdeev pseudopotential technique has been adopted for both parallel and oblique propagation of rarefactive solitary waves in a two electron temperature multi-ion plasma. The large amplitude solutions have consistently shown an increase in the width with increasing amplitude. The width-amplitude variation profile of obliquely propagating rarefactive solitary waves in a magnetized plasma have been compared with the recent POLAR observations. The width-amplitude variation pattern is found to fit well with the analytical results. It indicates that a fully nonlinear theory of ion acoustic solitary waves may well explain the observed anomalous width variations of large amplitude structures in the auroral region.

  5. Polycythemia, capillary rarefaction, and focal glomerulosclerosis in two adolescents born extremely low birth weight and premature.

    Science.gov (United States)

    Asada, Nariaki; Tsukahara, Takanori; Furuhata, Megumi; Matsuoka, Daisuke; Noda, Shunsuke; Naganuma, Kuniaki; Hashiguchi, Akinori; Awazu, Midori

    2017-07-01

    Low birthweight infants have a reduced number of nephrons and are at high risk of chronic kidney disease. Preterm birth and/or intrauterine growth restriction (IUGR) may also affect peritubular capillary development, as has been shown in other organs. We report two patients with a history of preterm birth and extremely low birthweight who showed polycythemia and renal capillary rarefaction. Patient 1 and 2, born at 25 weeks of gestation with a birthweight of 728 and 466 g, showed mild proteinuria at age 8 and 6 years, respectively. In addition to increasing proteinuria, hemoglobin levels became elevated towards adolescence and their serum erythropoietin (EPO) was high despite polycythemia. Light microscopic examination of renal biopsy specimens showed glomerular hypertrophy, focal segmental glomerulosclerosis, and only mild tubulointerstitial fibrosis. A decrease in the immunohistochemical staining of CD31 and CD34 endothelial cells in renal biopsy specimens was consistent with peritubular capillary rarefaction. Since kidney function was almost normal and fibrosis was not severe, we consider that the capillary rarefaction and polycythemia associated with elevated EPO levels were largely attributable to preterm birth and/or IUGR.

  6. Aging causes collateral rarefaction and increased severity of ischemic injury in multiple tissues

    Science.gov (United States)

    Faber, James E.; Zhang, Hua; Lassance-Soares, Roberta M.; Prabhakar, Pranay; Najafi, Amir H.; Burnett, Mary Susan; Epstein, Stephen E.

    2011-01-01

    Objective Aging is a major risk factor for increased ischemic tissue injury. Whether collateral rarefaction and impaired remodeling contribute to this is unknown. We quantified the number and diameter of native collaterals, and their remodeling in 3-, 16-, 24-, and 31-months-old mice. Methods and Results Aging caused an “age-dose-dependent” greater drop in perfusion immediately after femoral artery ligation, followed by a diminished recovery of flow and increase in tissue injury. These effects were associated with a decline in collateral number, diameter and remodeling. Angiogenesis was also impaired. Mechanistically, these changes were not accompanied by reduced recruitment of T-cells or macrophages to remodeling collaterals. However, eNOS signaling was dysfunctional, as indicated by increased protein nitrosylation and less phosphorylated eNOS and VASP in collateral wall cells. The cerebral circulation exhibited a similar age-dose-dependent loss of collateral number and diameter and increased tortuosity, resulting in an increase in collateral resistance and infarct volume (e.g., 6- and 3-fold, respectively, in 24-months-old mice) after artery occlusion. This was not associated with rarefaction of similarly-sized arterioles. Collateral remodeling was also reduced. Conclusions Our findings demonstrate that aging causes rarefaction and insufficiency of the collateral circulation in multiple tissues, resulting in more severe ischemic tissue injury. PMID:21617137

  7. Longitudinal MRI evaluation of intracranial development and vascular characteristics of breast cancer brain metastases in a mouse model.

    Directory of Open Access Journals (Sweden)

    Heling Zhou

    Full Text Available Longitudinal MRI was applied to monitor intracranial initiation and development of brain metastases and assess tumor vascular volume and permeability in a mouse model of breast cancer brain metastases. Using a 9.4T system, high resolution anatomic MRI and dynamic susceptibility contrast (DSC perfusion MRI were acquired at different time points after an intracardiac injection of brain-tropic breast cancer MDA-MB231BR-EGFP cells. Three weeks post injection, multifocal brain metastases were first observed with hyperintensity on T2-weighted images, but isointensity on T1-weighted post contrast images, indicating that blood-tumor-barrier (BTB at early stage of brain metastases was impermeable. Follow-up MRI revealed intracranial tumor growth and increased number of metastases that distributed throughout the whole brain. At the last scan on week 5, T1-weighted post contrast images detected BTB disruption in 160 (34% of a total of 464 brain metastases. Enhancement in some of the metastases was only seen in partial regions of the tumor, suggesting intratumoral heterogeneity of BTB disruption. DSC MRI measurements of relative cerebral blood volume (rCBV showed that rCBV of brain metastases was significantly lower (mean= 0.89±0.03 than that of contralateral normal brain (mean= 1.00±0.03; p<0.005. Intriguingly, longitudinal measurements revealed that rCBV of individual metastases at early stage was similar to, but became significantly lower than that of contralateral normal brain with tumor growth (p<0.05. The rCBV data were concordant with histological analysis of microvascular density (MVD. Moreover, comprehensive analysis suggested no significant correlation among tumor size, rCBV and BTB permeability. In conclusion, longitudinal MRI provides non-invasive in vivo assessments of spatial and temporal development of brain metastases and their vascular volume and permeability. The characteristic rCBV of brain metastases may have a diagnostic value.

  8. Cytocompatibility and biologic characteristics of synthetic scaffold materials of rabbit acellular vascular matrix combining with human-like collagen I.

    Science.gov (United States)

    Liu, Xuqian; Wang, Jie; Dong, Fusheng; Song, Peng; Tian, Songbo; Li, Hexiang; Hou, Yali

    2017-10-01

    Scaffold material provides a three-dimensional growing environment for seed cells in the research field of tissue engineering. In the present study, rabbit arterial blood vessel cells were chemically removed with trypsin and Triton X-100 to prepare rabbit acellular vascular matrix scaffold material. Observation by He&Masson staining revealed that no cellular components or nuclei existed in the vascular intima and media after decellularization. Human-like collagen I was combined with acellular vascular matrix by freeze-drying to prepare an acellular vascular matrix-0.25% human-like collagen I scaffold to compensate for the extracellular matrix loss during the decellularization process. We next performed a series of experiments to test the water absorbing quality, biomechanics, pressure resistance, cytotoxicity, and ultra-micro structure of the acellular vascular matrix composite material and natural rabbit artery and found that the acellular vascular matrix-0.25% human-like collagen I material behaved similarly to natural rabbit artery. In conclusion, the acellular vascular matrix-0.25% human-like collagen I composite material provides a new approach and lays the foundation for novel scaffold material research into tissue engineering of blood vessels.

  9. Shock and rarefaction waves in a hyperbolic model of incompressible materials

    Directory of Open Access Journals (Sweden)

    Tommaso Ruggeri

    2013-01-01

    Full Text Available The aim of the present paper is to investigate shock and rarefaction waves in a hyperbolic model of incompressible materials. To this aim, we use the so-called extended quasi-thermal-incompressible (EQTI model, recently proposed by Gouin & Ruggeri (H. Gouin, T. Ruggeri, Internat. J. Non-Linear Mech. 47 688–693 (2012. In particular, we use as constitutive equation a variant of the well-known Bousinnesq approximation in which the specific volume depends not only on the temperature but also on the pressure. The limit case of ideal incompressibility, namely when the thermal expansion coefficient and the compressibility factor vanish, is also considered.

  10. Characteristic pattern of cerebral perfusion in patients with the early stage of subcortical vascular dementia compared with Alzheimer's disease

    International Nuclear Information System (INIS)

    Jeong, Young Jin; Kang, Do Young; Park, Kyung Won; Cheon, Sang Myung; Kim, Jong Kuk; Kim, Jae Woo

    2004-01-01

    Brain perfusion SPECT has been commonly used to evaluate several different types of dementia. The aim of this study is to assess the specific patterns of regional cerebral blood flow (rCBF) in patients with the early stage of subcortical vascular dementia (SVD) and Alzheimer's disease (AD) using Tc-99m HMPAO SPECT, and to compare the differences between the two conditions. Sixteen SVD (mean age; 68.0±7.0 years, educational period; 6.3±5.6 years, CDR; 0.80±0.26). 46 AD (mean age; 69.9±7.4 years, educational period; 5.4±4.7 years, CDR; 0.86±0.23) and 12 normal control subjects (mean age; 67.1±7.7 years, educational period; 6.2±4.2 years) participated in this study. We included the patients with SVD and AD according to NINCDS-ADRDA criteria for probable AD and NINDS-AIREN criteria for probable or possible VD. They were all matched for age, education and clinical dementia scale scores. SPM analysis of the SPECT image showed significant perfusion deficits on the right temporal region and right thalamus, left insula and superior temporal gyrus, both cingulate gyri and frontal subgyral regions in patients with SVD and on the left supramarginal gyrus, superior temporal gyrus, postcentral gyrus and inferior parietal lobule, right fugiform gyrus and both cingulate gyri in patients with AD compared with control subjects (uncorrected p<0.01). SVD patients revealed significant hypoperfusion in the right parahippocampal gyrus, right cingulated gyrus, left insula, and both frontal subgyral regions compared with AD patients (uncorrected p<0.01). SVD patients revealed significant hyperperfusion in right superior frontal gyrus, left pre- and postcentral gyri, left paracentral lobule, left precuneus and both medial frontal gyri compared with AD patients (uncorrected p<0.01). Our study shows characteristic and different pattern of perfusion deficits in patients with SVD and AD, and these results may be helpful to discriminate the two conditions in the early stage of illness

  11. Operative variables are better predictors of postdischarge infections and unplanned readmissions in vascular surgery patients than patient characteristics.

    Science.gov (United States)

    Hicks, Caitlin W; Bronsert, Michael; Hammermeister, Karl E; Henderson, William G; Gibula, Douglas R; Black, James H; Glebova, Natalia O

    2017-04-01

    Although postoperative readmissions are frequent in vascular surgery patients, the reasons for these readmissions are not well characterized, and effective approaches to their reduction are unknown. Our aim was to analyze the reasons for vascular surgery readmissions and to report potential areas for focused efforts aimed at readmission reduction. The 2012 to 2013 American College of Surgeons National Quality Improvement Program (ACS NSQIP) data set was queried for vascular surgery patients. Multivariable models were developed to analyze risk factors for postdischarge infections, the major drivers of unplanned 30-day readmissions. We identified 86,403 vascular surgery patients for analysis. Thirty-day readmission occurred in 8827 (10%), of which 8054 (91%) were unplanned. Of the unplanned readmissions, 61% (n = 4951) were related to the index vascular surgery procedure. Infectious complications were the most common reason for a surgery-related readmission (1940 [39%]), with surgical site infection being the most common type of infection related to unplanned readmission. Multivariable analysis showed the top five preoperative risk factors for postdischarge infections were the presence of a preoperative open wound, inpatient operation, obesity, work relative value unit, and insulin-dependent diabetes (but not diabetes managed with oral medications). Cigarette smoking was a weak predictor and came in tenth in the mode (overall C index, 0.657). When operative and postoperative factors were included in the model, total operative time was the strongest predictor of postdischarge infectious complications (odds ratio [OR] 1.2 for each 1-hour increase in operative time), followed by presence of a preoperative open wound (OR, 1.5), inpatient operation (OR, 2), obesity (OR, 1.8), and discharge to rehabilitation facility (OR, 1.7; P model was fair (C statistic, 0.686). Infectious complications dominate the reasons for unplanned 30-day readmissions in vascular surgery

  12. Numerical investigation of rarefaction effects in the vicinity of a sharp leading edge

    Science.gov (United States)

    Pan, Shaowu; Gao, Zhenxun; Lee, Chunhian

    2014-12-01

    This paper presents a study of rarefaction effect on hypersonic flow over a sharp leading edge. Both continuum approach and kinetic method: a widely spread commercial Computational Fluid Dynamics-Navior-Stokes-Fourier (CFD-NSF) software - Fluent together with a direct simulation Monte Carlo (DSMC) code developed by the authors are employed for simulation of transition regime with Knudsen number ranging from 0.005 to 0.2. It is found that Fluent can predict the wall fluxes in the case of hypersonic argon flow over the sharp leading edge for the lowest Kn case (Kn = 0.005) in current paper while for other cases it also has a good agreement with DSMC except at the location near the sharp leading edge. Among all of the wall fluxes, it is found that coefficient of pressure is the most sensitive to rarefaction while heat transfer is the least one. A parameter based on translational nonequilibrium and a cut-off value of 0.34 is proposed for continuum breakdown in this paper. The structure of entropy and velocity profile in boundary layer is analyzed. Also, it is found that the ratio of heat transfer coefficient to skin friction coefficient remains uniform along the surface for the four cases in this paper.

  13. PIC simulation of a thermal anisotropy-driven Weibel instability in a circular rarefaction wave

    International Nuclear Information System (INIS)

    Dieckmann, M E; Sarri, G; Kourakis, I; Borghesi, M; Murphy, G C; O'C Drury, L; Bret, A; Romagnani, L; Ynnerman, A

    2012-01-01

    The expansion of an initially unmagnetized planar rarefaction wave has recently been shown to trigger a thermal anisotropy-driven Weibel instability (TAWI), which can generate magnetic fields from noise levels. It is examined here whether the TAWI can also grow in a curved rarefaction wave. The expansion of an initially unmagnetized circular plasma cloud, which consists of protons and hot electrons, into a vacuum is modelled for this purpose with a two-dimensional particle-in-cell (PIC) simulation. It is shown that the momentum transfer from the electrons to the radially accelerating protons can indeed trigger a TAWI. Radial current channels form and the aperiodic growth of a magnetowave is observed, which has a magnetic field that is oriented orthogonal to the simulation plane. The induced electric field implies that the electron density gradient is no longer parallel to the electric field. Evidence is presented here that this electric field modification triggers a second magnetic instability, which results in a rotational low-frequency magnetowave. The relevance of the TAWI is discussed for the growth of small-scale magnetic fields in astrophysical environments, which are needed to explain the electromagnetic emissions by astrophysical jets. It is outlined how this instability could be examined experimentally. (paper)

  14. PIC simulation of a thermal anisotropy-driven Weibel instability in a circular rarefaction wave

    Science.gov (United States)

    Dieckmann, M. E.; Sarri, G.; Murphy, G. C.; Bret, A.; Romagnani, L.; Kourakis, I.; Borghesi, M.; Ynnerman, A.; O'C Drury, L.

    2012-02-01

    The expansion of an initially unmagnetized planar rarefaction wave has recently been shown to trigger a thermal anisotropy-driven Weibel instability (TAWI), which can generate magnetic fields from noise levels. It is examined here whether the TAWI can also grow in a curved rarefaction wave. The expansion of an initially unmagnetized circular plasma cloud, which consists of protons and hot electrons, into a vacuum is modelled for this purpose with a two-dimensional particle-in-cell (PIC) simulation. It is shown that the momentum transfer from the electrons to the radially accelerating protons can indeed trigger a TAWI. Radial current channels form and the aperiodic growth of a magnetowave is observed, which has a magnetic field that is oriented orthogonal to the simulation plane. The induced electric field implies that the electron density gradient is no longer parallel to the electric field. Evidence is presented here that this electric field modification triggers a second magnetic instability, which results in a rotational low-frequency magnetowave. The relevance of the TAWI is discussed for the growth of small-scale magnetic fields in astrophysical environments, which are needed to explain the electromagnetic emissions by astrophysical jets. It is outlined how this instability could be examined experimentally.

  15. Rarefaction and shock waves for multi-dimensional hyperbolic conservation laws

    International Nuclear Information System (INIS)

    Dening, Li

    1991-01-01

    In this paper, the author wants to show the local existence of a solution of combination of shock and rarefaction waves for the multi-dimensional hyperbolic system of conservation laws. The typical example he has in mind is the Euler equations for compressible fluid. More generally, he studies the hyperbolic system of conservation laws ∂ t F 0 (u) + Σ j=1 n ∂ x j F j (u)=0 where u=(u 1 ....,u m ) and F j (u), j=0,...,n are m-dimensional vector-valued functions. He'll impose some conditions in the following on the systems (1.2). All these conditions are satisfied by the Euler equations

  16. Albedo of X-ray through the region of rarefaction wave

    International Nuclear Information System (INIS)

    Zhang Jun

    2001-01-01

    In the process of implosion indirectly driven by laser, the high temperature and low density plasma produced by X-ray ablation is in the state of non-local thermodynamic equilibrium. And the propagation of X-ray needs to be treated by transportation method. X-ray energy flow reflected by plasma depends on the density, temperature of radiation and electrons, and their space profiles if the plasma produced by ablation is fully ionized. In addition, the plasma parameters in the region of rarefaction wave is determined by means of a simplified model. The approach to compute X-ray albedo is presented and the analytical formulae of the albedo are given

  17. Reflected rarefactions, double regular reflection, and mach waves in aluminum and beryllium

    International Nuclear Information System (INIS)

    Neal, T.

    1975-01-01

    A number of shock techniques which can be used to obtain high-pressure equation-of-state information between the principal Hugoniot and the principal adiabat are illustrated. A rarefaction wave in aluminum shocked to 27.7 GPa [277 kbar] is examined with radiographic techniques and the bulk sound speed is determined. The two stage compression which occurs in a double shock may be attained by colliding two shocks and observing regular reflection. A radiographic method which uses this phenomenon to measure a three-stage compression of aluminum to a density of 4.7 Mg/m 3 and beryllium to a density of 3.1 Mg/m 3 is presented. The results of a Mach reflection experiment in aluminum are found to disagree substantially with the simple three-shock model. A modified model, consistent with observations, is discussed. In all cases the Gruneisen parameter is determined. (U.S.)

  18. Asymptotic freeze-out of the perturbations generated inside a corrugated rarefaction wave

    International Nuclear Information System (INIS)

    Wouchuk, J.G.; Serrano Rodrigo, A.D.

    2004-01-01

    Based on previous work [J. G. Wouchuk and R. Carretero, Phys. Plasmas 10, 4237 (2003)], the conditions of asymptotic freeze-out of the ripples at the tail of a corrugated rarefaction wave are analyzed. The precise location of the freezing-out regions in the space of preshock parameters is tried, and an efficient algorithm for their determination is given. It is seen that asymptotic freeze-out can only happen for gases that have an isentropic exponent γ cr ≅2.2913hellip. It is shown that the late time freeze-out of the ripple perturbations is correlated to the initial tangential velocity profile (at t=0+) inside the expansion fan

  19. [Clinical and laboratory characteristics of patients with pulmonary hypertension and pulmonary vascular complications hospitalized at the Instituto Nacional de Salud del Niño].

    Science.gov (United States)

    Ormeño Julca, Alexis Jose; Alvarez Murillo, Carlos Melchor; Amoretti Alvino, Pedro Miguel; Florian Florian, Angel Aladino; Castro Johanson, Rosa Aurora; Celi Perez, Maria Danisa; Huamán Prado, Olga Rocío

    2017-01-01

    The hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PPHN) are distinct pulmonary vascular complications of portal hypertension (PHT) and are associated with increased morbidity and mortality. To describe the clinical and laboratory characteristics of patients with pulmonary hypertension and pulmonary vascular complications hospitalized at the Instituto Nacional de Salud del Niño. We included patients with HTP hospitalized from January 2012 to June 2013 and that during its evolution progressed with SHP or HTPP. For analysis, they were divided into a first group of patients with liver cirrhosis and a second group with extrahepatic portal vein obstruction. Of 22 patients with HPT 45.5% were male and the age range was between 1 month and 17 years. The etiology in the group of cirrhosis (n=14) was: autoimmune hepatitis (35.7%), cryptogenic cirrhosis (35.7%), inborn error of metabolism (14.3%), chronic viral hepatitis C (7.15%) virus and atresia extra-hepatic bile ducts (7.15%). Pulmonary vascular complications more frequently occurred in patients with liver cirrhosis (1 case of HPS and a case of PPHTN). They most often dyspnea, asthenia, edema, malnutrition, ascites, hypersplenism and gastrointestinal bleeding from esophageal varices was found. Also, they had elevated ALT values, alkaline phosphatase and serum albumin values decreased. In children with pulmonary hypertension, pulmonary vascular complications are rare. In the evaluation of these patients pulse oximetry should be included to detect hypoxemia and ubsequently a Doppler echocardiography and contrast echocardiography necessary. Dueto the finding of systolic pulmonary hypertension it is necessary to perform right heart catheterization.

  20. Community assessment techniques and the implications for rarefaction and extrapolation with Hill numbers.

    Science.gov (United States)

    Cox, Kieran D; Black, Morgan J; Filip, Natalia; Miller, Matthew R; Mohns, Kayla; Mortimor, James; Freitas, Thaise R; Greiter Loerzer, Raquel; Gerwing, Travis G; Juanes, Francis; Dudas, Sarah E

    2017-12-01

    Diversity estimates play a key role in ecological assessments. Species richness and abundance are commonly used to generate complex diversity indices that are dependent on the quality of these estimates. As such, there is a long-standing interest in the development of monitoring techniques, their ability to adequately assess species diversity, and the implications for generated indices. To determine the ability of substratum community assessment methods to capture species diversity, we evaluated four methods: photo quadrat, point intercept, random subsampling, and full quadrat assessments. Species density, abundance, richness, Shannon diversity, and Simpson diversity were then calculated for each method. We then conducted a method validation at a subset of locations to serve as an indication for how well each method captured the totality of the diversity present. Density, richness, Shannon diversity, and Simpson diversity estimates varied between methods, despite assessments occurring at the same locations, with photo quadrats detecting the lowest estimates and full quadrat assessments the highest. Abundance estimates were consistent among methods. Sample-based rarefaction and extrapolation curves indicated that differences between Hill numbers (richness, Shannon diversity, and Simpson diversity) were significant in the majority of cases, and coverage-based rarefaction and extrapolation curves confirmed that these dissimilarities were due to differences between the methods, not the sample completeness. Method validation highlighted the inability of the tested methods to capture the totality of the diversity present, while further supporting the notion of extrapolating abundances. Our results highlight the need for consistency across research methods, the advantages of utilizing multiple diversity indices, and potential concerns and considerations when comparing data from multiple sources.

  1. Time-resolved magnetic resonance angiography (MRA) at 3.0 Tesla for evaluation of hemodynamic characteristics of vascular malformations: description of distinct subgroups.

    Science.gov (United States)

    Hammer, Simone; Uller, Wibke; Manger, Florentine; Fellner, Claudia; Zeman, Florian; Wohlgemuth, Walter A

    2017-01-01

    Quantitative evaluation of hemodynamic characteristics of arteriovenous and venous malformations using time-resolved magnetic resonance angiography (MRA) at 3.0 Tesla. Time-resolved MRA with interleaved stochastic trajectories (TWIST) at 3.0 Tesla was studied in 83 consecutive patients with venous malformations (VM) and arteriovenous malformations (AVM). Enhancement characteristics were calculated as percentage increase of signal intensity above baseline over time. Maximum percentage signal intensity increase (signal max ), time intervals between onset of arterial enhancement and lesion enhancement (t onset ), and time intervals between beginning of lesion enhancement and maximum percentage of lesion enhancement (t max ) were analyzed. All AVMs showed a high-flow hemodynamic pattern. Two significantly different (p 3.0 Tesla provides hemodynamic characterization of vascular malformations. VMs can be subclassified into two hemodynamic subgroups due to presence or absence of AVFs. • Time-resolved MRA at 3.0 Tesla provides quantitative hemodynamic characterization of vascular malformations. • Malformations significantly differ in time courses of enhancement and signal intensity increase. • AVMs show a distinctive high-flow hemodynamic pattern. • Two significantly different types of VMs emerged: VMs with and without AVFs.

  2. Normal velocity freeze-out of the Richtmyer-Meshkov instability when a rarefaction is reflected

    Science.gov (United States)

    Wouchuk, J. G.; Sano, T.

    2015-02-01

    The Richtmyer-Meshkov instability (RMI) develops when a shock front hits a rippled contact surface separating two different fluids. After the incident shock refraction, a transmitted shock is always formed and another shock or a rarefaction is reflected back. The pressure-entropy-vorticity fields generated by the rippled wave fronts are responsible for the generation of hydrodynamic perturbations in both fluids. In linear theory, the contact surface ripple reaches an asymptotic normal velocity which is dependent on the incident shock Mach number, fluids density ratio, and compressibilities. It was speculated in the past about the possibility of getting a zero value for the asymptotic normal velocity, a phenomenon that was called "freeze-out" [G. Fraley, Phys. Fluids 29, 376 (1986), 10.1063/1.865722; K. Mikaelian, Phys. Fluids 6, 356 (1994), 10.1063/1.868091, A. L. Velikovich et al., Phys. Plasmas 8, 592 (2001), 10.1063/1.1335829]. In a previous paper, freeze-out was studied for the case when a shock is reflected at the contact surface [J. G. Wouchuk and K. Nishihara, Phys. Rev. E 70, 026305 (2004), 10.1103/PhysRevE.70.026305]. In this work the freeze-out of the RMI is studied for the case in which a rarefaction is reflected back. Two different regimes are found: nearly equal preshock densities at the interface at any shock intensity, and very large density difference for strong shocks. The contour curves that relate shock Mach number and preshock density ratio are obtained in both regimes for fluids with equal and different compressibilities. An analysis of the temporal evolution of different cases of freeze-out is shown. It is seen that the freeze-out is the result of the interaction between the unstable interface and the rippled wave fronts. As a general and qualitative criterion to look for freeze-out situations, it is seen that a necessary condition for freeze-out is the same orientation for the tangential velocities generated at each side of the contact

  3. Appropriate control time constant in relation to characteristics of the baroreflex vascular system in 1/R control of the total artificial heart.

    Science.gov (United States)

    Mizuta, Sora; Saito, Itsuro; Isoyama, Takashi; Hara, Shintaro; Yurimoto, Terumi; Li, Xinyang; Murakami, Haruka; Ono, Toshiya; Mabuchi, Kunihiko; Abe, Yusuke

    2017-09-01

    1/R control is a physiological control method of the total artificial heart (TAH) with which long-term survival was obtained with animal experiments. However, 1/R control occasionally diverged in the undulation pump TAH (UPTAH) animal experiment. To improve the control stability of the 1/R control, appropriate control time constant in relation to characteristics of the baroreflex vascular system was investigated with frequency analysis and numerical simulation. In the frequency analysis, data of five goats in which the UPTAH was implanted were analyzed with first Fourier transform technique to examine the vasomotion frequency. The numerical simulation was carried out repeatedly changing baroreflex parameters and control time constant using the elements-expanded Windkessel model. Results of the frequency analysis showed that the 1/R control tended to diverge when very low frequency band that was an indication of the vasomotion frequency was relative high. In numerical simulation, divergence of the 1/R control could be reproduced and the boundary curves between the divergence and convergence of the 1/R control varied depending on the control time constant. These results suggested that the 1/R control tended to be unstable when the TAH recipient had high reflex speed in the baroreflex vascular system. Therefore, the control time constant should be adjusted appropriately with the individual vasomotion frequency.

  4. On the damping effect of gas rarefaction on propagation of acoustic waves in a microchannel

    Science.gov (United States)

    Manela, A.; Radtke, G. A.; Pogorelyuk, L.

    2014-03-01

    We consider the response of a gas in a microchannel to instantaneous (small-amplitude) non-periodic motion of its boundaries in the normal direction. The problem is formulated for an ideal monatomic gas using the Bhatnagar, Gross, and Krook (BGK) kinetic model, and solved for the entire range of Knudsen (Kn) numbers. Analysis combines analytical (collisionless and continuum-limit) solutions with numerical (low-variance Monte Carlo and linearized BGK) calculations. Gas flow, driven by motion of the boundaries, consists of a sequence of propagating and reflected pressure waves, decaying in time towards a final equilibrium state. Gas rarefaction is shown to have a "damping effect" on equilibration process, with the time required for equilibrium shortening with increasing Kn. Oscillations in hydrodynamic quantities, characterizing gas response in the continuum limit, vanish in collisionless conditions. The effect of having two moving boundaries, compared to only one considered in previous studies of time-periodic systems, is investigated. Comparison between analytical and numerical solutions indicates that the collisionless description predicts the system behavior exceptionally well for all systems of the size of the mean free path and somewhat larger, in cases where boundary actuation acts along times shorter than the ballistic time scale. The continuum-limit solution, however, should be considered with care at early times near the location of acoustic wavefronts, where relatively sharp flow-field variations result in effective increase in the value of local Knudsen number.

  5. Coupled Hydrodynamic Instability Growth on Oblique Interfaces with a Reflected Rarefaction

    Science.gov (United States)

    Rasmus, A. M.; Flippo, K. A.; di Stefano, C. A.; Doss, F. W.; Hager, J. D.; Merritt, E. C.; Cardenas, T.; Schmidt, D. W.; Kline, J. L.; Kuranz, C. C.

    2017-10-01

    Hydrodynamic instabilities play an important role in the evolution of inertial confinement fusion and astrophysical phenomena. Three of the Omega-EP long pulse beams (10 ns square pulse, 14 kJ total energy, 1.1 mm spot size) drive a supported shock across a heavy-to-light, oblique, interface. Single- and double-mode initial conditions seed coupled Richtmyer-Meshkov (RM), Rayleigh-Taylor (RT), and Kelvin-Helmholtz (KH) growth. At early times, growth is dominated by RM and KH, whereas at late times a rarefaction from laser turn-off reaches the interface, leading to decompression and RT growth. The addition of a thirty degree tilt does not alter mix width to within experimental error bars, even while significantly altering spike and bubble morphology. The results of single and double-mode experiments along with simulations using the multi-physics hydro-code RAGE will be presented. This work performed under the auspices of the U.S. Department of Energy by LANL under contract DE-AC52-06NA25396. This work is funded by the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, Grant Number DE-NA0002956. This material is partially supported by DOE Office of Science Graduate Student Research (SCGSR) program.

  6. [Value of condensation and rarefaction click evoked action potential latency difference in the diagnosis of Meniere's disease].

    Science.gov (United States)

    Wang, Z; Shao, X; Yan, W; Lin, H

    2000-06-01

    To study the value of condensation and rarefaction clicks evoked action potential (AP) latency difference (LD) in diagnosis of Meniere's disease. AP was recorded with ECochG in controls (50 ears) and patients with Meniere's disease(90 ears) and sensorineural hearing loss(SNHL) of other origins(60 ears). LD was calculated and analyzed. LD in patients with Meniere's disease was (0.30 +/- 0.15) ms, which was significantly larger than that of controls(0.18 +/- 0.07) ms and of patients with SNHL of other origins(0.20 +/- 0.10) ms (P curve was larger than those with flat auditory sensation curve(P rarefaction click evoked AP latency difference can be an objective parameter in diagnosis of Meniere's disease.

  7. Characteristics of Cerebral Blood Flow in Vascular Dementia using SPM Analysis Compared to Normal Control and Alzheimer's Dementia

    International Nuclear Information System (INIS)

    Kang, Do Young; Park, Kyung Won; Kim, Jae Woo

    2003-01-01

    Cerebral perfusion pattern of vascular dementia (VD) was not well established and overlap of cerebral perfusion pattern was reported between VD and Alzheimer's dementia (AD). The aim of this study is to assess the specific patterns of SPECT finding in VD compared with normal control subjects and to disclose differences of cerebral blood flow between subjects with VD and AD were investigated using statistic parametric mapping analysis. Thirty-two VD (mean age ; 67.86.4 years, mean CDR ; 0.980.27), 51 AD (mean age ; 71.47.2 years, CDR ; 1.160.47), which were matched for age and severity of dementia, and 30 normal control subjects (mean age ; 60.17.7 years) participated in this study. The Tc-99m HMPAO brain perfusion SPECT data were analyzed by SPM99. The SPECT data of the patients with VD were compared to those of the control subjects and then compared to the patients with AD. SPM analysis of the SPECT image showed significant perfusion deficits in the both frontal (both cingulate gyrus, both inferior frontal gyrus, B no.47, right frontal rectal gyrus, left frontal subcallosal gyrus, B no.25), both temporal (right insula, B no.13, left superior temporal gyrus, left parahippocampal gyrus, B no.35), occipital (occipital lingual gyrus), right corpus callosum and right cerebellar tonsil regions in subjects with VD compared with normal control subjects (uncorrected p<0.01). Comparison of the two dementia groups (uncorrected p<0.01) revealed significant hypoperfusion in both parietal posterior central gyrus, right inferior frontal gyrus (B no.47), left insula, right thalamus (ventral lateral nucleus), right claustrum and right occipital cuneus regions in VD group compared with AD. There were no typical confined regional hypoperfusion areas but scattered multiple perfusion deficits in VD compared AD. These findings may be helpful to reflect the pathophysiological mechanisms of VD and to disclose differences of cerebral blood flow between subjects with VD and AD

  8. [Characteristics of sublingual vein and expressions of vascular endothelial growth factor and hypoxia-inducible factor 1alpha proteins in sublingual tissues of Beagle dogs with portal hypertension].

    Science.gov (United States)

    Li, Bai-yu; Wang, Li-na; Yue, Xiao-qiang; Li, Bai

    2009-05-01

    To observe sublingual vein characteristics and the expressions of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor 1alpha (HIF-1alpha) proteins in sublingual tissues of Beagle dogs with cirrhotic portal hypertension. Twelve Beagle dogs were randomly divided into normal control group and cirrhotic portal hypertension group. There were 6 dogs in each group. A canine model of cirrhosis portal hypertension was established by injecting dimethylnitrosamine (DMN) into portal vein once a week for 7 weeks. The characteristics of sublingual vein were observed. Portal venous pressure was measured by using bioelectric recording techniques. The expressions of VEGF and HIF-1alpha proteins in sublingual vein were detected by immunohistochemical method. The shape and color of sublingual vein in beagle dogs in the cirrhotic portal hypertension group changed obviously as compared with the normal control group. Immunohistochemical results showed that there were almost no expressions of VEGF and HIF-1alpha proteins in sublingual tissues in the normal control group; however, the expressions of VEGF and HIF-1alpha proteins in sublingual tissues in the cirrhotic portal hypertension group significantly increased. Changes of portal pressure may lead to the formation of the abnormal sublingual vein by increasing the expressions of VEGF and HIF-1alpha proteins in sublingual tissues in Beagle dogs with portal hypertension.

  9. Time-resolved magnetic resonance angiography (MRA) at 3.0 Tesla for evaluation of hemodynamic characteristics of vascular malformations: description of distinct subgroups

    Energy Technology Data Exchange (ETDEWEB)

    Hammer, Simone; Fellner, Claudia; Wohlgemuth, Walter A. [University Hospital Regensburg, Department of Radiology, Regensburg (Germany); Uller, Wibke [Boston Children' s Hospital and Harvard Medical School, Division of Vascular and Interventional Radiology, Boston, MA (United States); University Hospital Regensburg, Department of Radiology, Regensburg (Germany); Manger, Florentine [University Hospital Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany); Zeman, Florian [University Hospital Regensburg, Center for Clinical Trials, Regensburg (Germany)

    2017-01-15

    Quantitative evaluation of hemodynamic characteristics of arteriovenous and venous malformations using time-resolved magnetic resonance angiography (MRA) at 3.0 Tesla. Time-resolved MRA with interleaved stochastic trajectories (TWIST) at 3.0 Tesla was studied in 83 consecutive patients with venous malformations (VM) and arteriovenous malformations (AVM). Enhancement characteristics were calculated as percentage increase of signal intensity above baseline over time. Maximum percentage signal intensity increase (signal{sub max}), time intervals between onset of arterial enhancement and lesion enhancement (t{sub onset}), and time intervals between beginning of lesion enhancement and maximum percentage of lesion enhancement (t{sub max}) were analyzed. All AVMs showed a high-flow hemodynamic pattern. Two significantly different (p < 0.001) types of venous malformations emerged: VMs with arteriovenous fistulas (AVF) (median signal{sub max} 737 %, IQR [interquartile range] = 511 - 1182 %; median t{sub onset} 5 s, IQR = 5 - 10 s; median t{sub max} 35 s, IQR = 26 - 40 s) and without AVFs (median signal{sub max} 284 %, IQR = 177-432 %; median t{sub onset} 23 s, IQR = 15 - 30 s; median t{sub max} 60 s, IQR = 55 - 75 s). Quantitative evaluation of time-resolved MRA at 3.0 Tesla provides hemodynamic characterization of vascular malformations. VMs can be subclassified into two hemodynamic subgroups due to presence or absence of AVFs. (orig.)

  10. Identification of capillary rarefaction using intracoronary wave intensity analysis with resultant prognostic implications for cardiac allograft patients.

    Science.gov (United States)

    Broyd, Christopher J; Hernández-Pérez, Francisco; Segovia, Javier; Echavarría-Pinto, Mauro; Quirós-Carretero, Alicia; Salas, Clara; Gonzalo, Nieves; Jiménez-Quevedo, Pilar; Nombela-Franco, Luis; Salinas, Pablo; Núñez-Gil, Ivan; Del Trigo, Maria; Goicolea, Javier; Alonso-Pulpón, Luis; Fernández-Ortiz, Antonio; Parker, Kim; Hughes, Alun; Mayet, Jamil; Davies, Justin; Escaned, Javier

    2018-05-21

    Techniques for identifying specific microcirculatory structural changes are desirable. As such, capillary rarefaction constitutes one of the earliest changes of cardiac allograft vasculopathy (CAV) in cardiac allograft recipients, but its identification with coronary flow reserve (CFR) or intracoronary resistance measurements is hampered because of non-selective interrogation of the capillary bed. We therefore investigated the potential of wave intensity analysis (WIA) to assess capillary rarefaction and thereby predict CAV. Fifty-two allograft patients with unobstructed coronary arteries and normal left ventricular (LV) function were assessed. Adequate aortic pressure and left anterior descending artery flow measurements at rest and with intracoronary adenosine were obtained in 46 of which 2 were lost to follow-up. In a subgroup of 15 patients, simultaneous RV biopsies were obtained and analysed for capillary density. Patients were followed up with 1-3 yearly screening angiography. A significant relationship with capillary density was noted with CFR (r = 0.52, P = 0.048) and the backward decompression wave (BDW) (r = -0.65, P < 0.01). Over a mean follow-up of 9.3 ± 5.2 years patients with a smaller BDW had an increased risk of developing angiographic CAV (hazard ratio 2.89, 95% CI 1.12-7.39; P = 0.03). Additionally, the index BDW was lower in those who went on to have a clinical CAV-events (P = 0.04) as well as more severe disease (P = 0.01). Within cardiac transplant patients, WIA is able to quantify the earliest histological changes of CAV and can predict clinical and angiographic outcomes. This proof-of-concept for WIA also lends weight to its use in the assessment of other disease processes in which capillary rarefaction is involved.

  11. Changes in Vascular Plant Biodiversity in the Netherlands in the 20th Century Explained by their Climatic and other Environmental Characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Tamis, W.L.M.; Van der Meijden, R.; Udo de Haes, H.A. [Nationaal Herbarium Nederland/Leiden University Branch, P.O. Box 9514, 2300, RA, Leiden (Netherlands); Van ' t Zelfde, M. [Institute of Environmental Sciences, Leiden University, P.O. Box 9518, 2300, RA, Leiden (Netherlands)

    2005-09-01

    In the Netherlands nation-wide databases are available with about 10 million records of occurrences of vascular plant species in the 20th century on a scale of approximately 1 km{sup 2}. These data were analysed with a view to identifying relationships between changes in botanical biodiversity and climatic and other environmental factors. Prior to analysis the data were corrected for several major forms of survey bias. The records were broken down into three periods: 1902-1949, 1975-1984 and 1985-1999. Using multiple regression analysis, differences between successive periods were related to plant functional characteristics as explanatory variables. Between the periods 1902-1949 and 1975-1984 there were small but significant increases in the presence of both thermophilic ('warm') and psychrophilic ('cold') species. However, in the final decades of the 20th century there was a marked increase in thermophilic species only, coinciding with the marked increase in ambient temperature observed during this period, evidence at least of a rapid response of Dutch flora to climate change. Urbanisation was also examined as an alternative explanation for the increase in thermophilic plant species and was found to explain only 50% of the increased presence of such species in the final decades of the 20th century. Besides temperature-related effects, the most important change during the 20th century was a strong decline in oligotrophic and a marked increase in eutrophic plant species.

  12. MgO melting curve constraints from shock temperature and rarefaction overtake measurements in samples preheated to 2300 K

    OpenAIRE

    Fat'yanov, Oleg V.; Asimow, P. D.

    2014-01-01

    Continuing our effort to obtain experimental constraints on the melting curve of MgO at 100-200 GPa, we extended our target preheating capability to 2300 K. Our new Mo capsule design holds a long MgO crystal in a controlled thermal gradient until impact by a Ta flyer launched at up to 7.5 km/s on the Caltech two-stage light-gas gun. Radiative shock temperatures and rarefaction overtake times were measured simultaneously by a 6-channel VIS/NIR pyrometer with 3 ns time resolution. The majority ...

  13. INTERVALS OF RADIAL INTERPLANETARY MAGNETIC FIELDS AT 1 AU, THEIR ASSOCIATION WITH RAREFACTION REGIONS, AND THEIR APPARENT MAGNETIC FOOT POINTS AT THE SUN

    Energy Technology Data Exchange (ETDEWEB)

    Orlove, Steven T.; Smith, Charles W.; Vasquez, Bernard J.; Schwadron, Nathan A. [Physics Department and Space Science Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH (United States); Skoug, Ruth M. [Los Alamos National Laboratory, MS D466, Los Alamos, NM 87545 (United States); Zurbuchen, Thomas H.; Zhao Liang, E-mail: stx33@wildcats.unh.edu, E-mail: Charles.Smith@unh.edu, E-mail: Bernie.Vasquez@unh.edu, E-mail: N.Schwadron@unh.edu, E-mail: rskoug@lanl.gov, E-mail: thomasz@umich.edu, E-mail: lzh@umich.edu [Department of Atmospheric, Oceanic and Space Science, University of Michigan, Ann Arbor, MI (United States)

    2013-09-01

    We have examined 226 intervals of nearly radial interplanetary magnetic field orientations at 1 AU lasting in excess of 6 hr. They are found within rarefaction regions as are the previously reported high-latitude observations. We show that these rarefactions typically do not involve high-speed wind such as that seen by Ulysses at high latitudes during solar minimum. We have examined both the wind speeds and the thermal ion composition before, during and after the rarefaction in an effort to establish the source of the flow that leads to the formation of the rarefaction. We find that the bulk of the measurements, both fast- and slow-wind intervals, possess both wind speeds and thermal ion compositions that suggest they come from typical low-latitude sources that are nominally considered slow-wind sources. In other words, we find relatively little evidence of polar coronal hole sources even when we examine the faster wind ahead of the rarefaction regions. While this is in contrast to high-latitude observations, we argue that this is to be expected of low-latitude observations where polar coronal hole sources are less prevalent. As with the previous high-latitude observations, we contend that the best explanation for these periods of radial magnetic field is interchange reconnection between two sources of different wind speed.

  14. VASCULAR SURGERY

    African Journals Online (AJOL)

    2016-06-02

    Jun 2, 2016 ... with the literature from South Africa over the last four decades, and reflects the high rate of interpersonal violence in the country.14,15 As expected, cervical ... via the intact circle of Willis in young patients is the most likely explanation for the lack of strokes. Five patients were referred to the Durban vascular ...

  15. Vascular Disorders

    Science.gov (United States)

    ... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is a Hand Therapist? Media Find a Hand Surgeon Home Anatomy Vascular Disorders Email to a friend * required fields ...

  16. Healing of apical rarefaction of three nonvital open apex anterior teeth using a white portland cement apical plug

    Directory of Open Access Journals (Sweden)

    Amitabha Chakraborty

    2012-01-01

    Full Text Available The major challenge of performing root canal treatment in an open apex pulp-less tooth is to obtain a good apical seal. MTA has been successfully used to achieve a good apical seal, wherein the root canal obturation can be done immediately. MTA and White Portland Cement has been shown similarity in their physical, chemical and biological properties and has also shown similar outcome when used in animal studies and human trials. In our study, open apex of three non vital upper central incisors has been plugged using modified white Portland cement. 3 to 6 months follow up revealed absence of clinical symptoms and disappearance of peri-apical rarefactions. The positive clinical outcome may encourage the future use of white Portland cement as an apical plug material in case of non vital open apex tooth as much cheaper substitute of MTA.

  17. Network of vascular diseases, death and biochemical characteristics in a set of 4,197 patients with type 1 diabetes (The FinnDiane Study

    Directory of Open Access Journals (Sweden)

    Wadén Johan

    2009-10-01

    Full Text Available Background Cardiovascular disease is the main cause of premature death in patients with type 1 diabetes. Patients with diabetic kidney disease have an increased risk of heart attack or stroke. Accurate knowledge of the complex inter-dependencies between the risk factors is critical for pinpointing the best targets for research and treatment. Therefore, the aim of this study was to describe the association patterns between clinical and biochemical features of diabetic complications. Methods Medical records and serum and urine samples of 4,197 patients with type 1 diabetes were collected from health care centers in Finland. At baseline, the mean diabetes duration was 22 years, 52% were male, 23% had kidney disease (urine albumin excretion over 300 mg/24 h or end-stage renal disease and 8% had a history of macrovascular events. All-cause mortality was evaluated after an average of 6.5 years of follow-up (25,714 patient years. The dataset comprised 28 clinical and 25 biochemical variables that were regarded as the nodes of a network to assess their mutual relationships. Results The networks contained cliques that were densely inter-connected (r > 0.6, including cliques for high-density lipoprotein (HDL markers, for triglycerides and cholesterol, for urinary excretion and for indices of body mass. The links between the cliques showed biologically relevant interactions: an inverse relationship between HDL cholesterol and the triglyceride clique (r P -16, a connection between triglycerides and body mass via C-reactive protein (r > 0.3, P -16 and intermediate-density cholesterol as the connector between lipoprotein metabolism and albuminuria (r > 0.3, P -16. Aging and macrovascular disease were linked to death via working ability and retinopathy. Diabetic kidney disease, serum creatinine and potassium, retinopathy and blood pressure were inter-connected. Blood pressure correlations indicated accelerated vascular aging in individuals with kidney disease

  18. Characteristic pattern of cerebral perfusion in patients with the early stage of subcortical vascular dementia compared with Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Young Jin; Kang, Do Young; Park, Kyung Won; Cheon, Sang Myung; Kim, Jong Kuk; Kim, Jae Woo [Dong-A University School of Medicine, Busan (Korea, Republic of)

    2004-07-01

    Brain perfusion SPECT has been commonly used to evaluate several different types of dementia. The aim of this study is to assess the specific patterns of regional cerebral blood flow (rCBF) in patients with the early stage of subcortical vascular dementia (SVD) and Alzheimer's disease (AD) using Tc-99m HMPAO SPECT, and to compare the differences between the two conditions. Sixteen SVD (mean age; 68.0{+-}7.0 years, educational period; 6.3{+-}5.6 years, CDR; 0.80{+-}0.26). 46 AD (mean age; 69.9{+-}7.4 years, educational period; 5.4{+-}4.7 years, CDR; 0.86{+-}0.23) and 12 normal control subjects (mean age; 67.1{+-}7.7 years, educational period; 6.2{+-}4.2 years) participated in this study. We included the patients with SVD and AD according to NINCDS-ADRDA criteria for probable AD and NINDS-AIREN criteria for probable or possible VD. They were all matched for age, education and clinical dementia scale scores. SPM analysis of the SPECT image showed significant perfusion deficits on the right temporal region and right thalamus, left insula and superior temporal gyrus, both cingulate gyri and frontal subgyral regions in patients with SVD and on the left supramarginal gyrus, superior temporal gyrus, postcentral gyrus and inferior parietal lobule, right fugiform gyrus and both cingulate gyri in patients with AD compared with control subjects (uncorrected p<0.01). SVD patients revealed significant hypoperfusion in the right parahippocampal gyrus, right cingulated gyrus, left insula, and both frontal subgyral regions compared with AD patients (uncorrected p<0.01). SVD patients revealed significant hyperperfusion in right superior frontal gyrus, left pre- and postcentral gyri, left paracentral lobule, left precuneus and both medial frontal gyri compared with AD patients (uncorrected p<0.01). Our study shows characteristic and different pattern of perfusion deficits in patients with SVD and AD, and these results may be helpful to discriminate the two conditions in the

  19. Rationale, design and baseline characteristics of the CANagliflozin cardioVascular Assessment Study-Renal (CANVAS-R) : A randomized, placebo-controlled trial

    NARCIS (Netherlands)

    Neal, Bruce; Perkovic, Vlado; Matthews, David R.; Mahaffey, Kenneth W.; Fulcher, Greg; Meininger, Gary; Erondu, Ngozi; Desai, Mehul; Shaw, Wayne; Vercruysse, Frank; Yee, Jacqueline; Deng, Hsiaowei; de Zeeuw, Dick

    Aims: The primary aim of the CANagliflozin cardioVascular Assessment Study-Renal (CANVAS-R) is to determine whether the favourable effects of inhibition of the sodium glucose co-transporter 2 (SGLT2) on blood glucose, blood pressure and body weight are accompanied by protection against adverse renal

  20. Vascular ultrasound.

    Science.gov (United States)

    Pilcher, D B; Ricci, M A

    1998-04-01

    Surgeon-interpreted diagnostic ultrasound has become the preferred screening test and often the definitive test for the diagnosis of arterial stenosis, aneurysm, and venous thrombosis. As a modality for surveillance, its noninvasive quality makes it particularly appealing as the test of choice to screen patients for abdominal aortic aneurysms or to perform follow-up examinations on those patients with a carotid endartectomy or in situ bypass grafts. The increasing reliance on intraoperative duplex imaging of vascular procedures demands that the surgeon learn the skills to perform the studies without a technologist or radiologist to interpret the examination.

  1. Pulmonary vascular imaging

    International Nuclear Information System (INIS)

    Fedullo, P.F.; Shure, D.

    1987-01-01

    A wide range of pulmonary vascular imaging techniques are available for the diagnostic evaluation of patients with suspected pulmonary vascular disease. The characteristics of any ideal technique would include high sensitivity and specificity, safety, simplicity, and sequential applicability. To date, no single technique meets these ideal characteristics. Conventional pulmonary angiography remains the gold standard for the diagnosis of acute thromboembolic disease despite the introduction of newer techniques such as digital subtraction angiography and magnetic resonance imaging. Improved noninvasive lower extremity venous testing methods, particularly impedance plethysmography, and ventilation-perfusion scanning can play significant roles in the noninvasive diagnosis of acute pulmonary emboli when properly applied. Ventilation-perfusion scanning may also be useful as a screening test to differentiate possible primary pulmonary hypertension from chronic thromboembolic pulmonary hypertension. And, finally, angioscopy may be a useful adjunctive technique to detect chronic thromboembolic disease and determine operability. Optimal clinical decision-making, however, will continue to require the proper interpretation of adjunctive information obtained from the less-invasive techniques, applied with an understanding of the natural history of the various forms of pulmonary vascular disease and with a knowledge of the capabilities and shortcomings of the individual techniques

  2. Influences of maternal nutritional status on vascular function in the offspring.

    Science.gov (United States)

    Poston, Lucilla

    2007-08-01

    Fetal growth restriction leading to low birthweight is associated with increased risk of ischaemic heart disease and hypertension in later life. Increasingly, it is recognised that cardiovascular risk may also be initiated in early life when the fetus and neonate are exposed to maternal nutritional excess. This review summarises the studies in man and animals that have investigated the potential role of vascular disorders in the aetiology of atherosclerosis and hypertension arising from early life nutritional deprivation or excess. Malfunction of the arterial endothelial cell layer in the offspring has been frequently described in association with both maternal under and overnutritional states and may play a permissive role in the origin of these disorders. Also prevalent is evidence for increased stiffness of the large arteries which may contribute to systolic hypertension. Further investigation is required into the intriguing suggestion that early life nutritional imbalance may adversely influence vascular angiogenesis leading to rarefaction and increased peripheral vascular resistance.

  3. Vascular lesions following radiation

    International Nuclear Information System (INIS)

    Fajardo, L.F.; Berthrong, M.

    1988-01-01

    The special radiation sensitivity of the vascular system is mainly linked to that of endothelial cells, which are perhaps the most radiation-vulnerable elements of mesenchymal tissues. Within the vascular tree, radiation injures most often capillaries, sinusoids, and small arteries, in that order. Lesions of veins are observed less often, but in certain tissues the veins are regularly damaged (e.g., intestine) or are the most affected structures (i.e., liver). Large arteries do suffer the least; however, when significant damage does occur in an elastic artery (e.g., thrombosis or rupture), it tends to be clinically significant and even fatal. Although not always demonstrable in human tissues, radiation vasculopathy generally is dose and time dependent. Like other radiation-induced lesions, the morphology in the vessels is not specific, but it is characteristic enough to be often recognizable. Vascular injury, especially by therapeutic radiation is not just a morphologic marker. It is a mediator of tissue damage; perhaps the most consistent pathogenetic mechanism in delayed radiation injury

  4. Compressibility and rarefaction effects on entropy and entropy generation in micro/nano Couette flow using DSMC

    International Nuclear Information System (INIS)

    Ejtehadi, Omid; Esfahani, Javad Abolfazli; Roohi, Ehsan

    2012-01-01

    In the present work, compressible flow of argon gas in the famous problem of Couette flow in micro/nano-scale is considered and numerically analyzed using the direct simulation Monte Carlo (DSMC) method. The effects of compressibility and rarefaction on entropy and entropy generation in terms of viscous dissipation and thermal diffusion are studied in a wide range of Mach and Knudsen numbers and the observed physics are discussed. In this regard, we computed entropy by using its kinetic theory formulation in a microscopic way while the entropy generation distribution is achieved by applying a semi-microscopic approach and thoroughly free from equilibrium assumptions. The results of our simulations demonstrated that the entropy profiles are in accordance with the temperature profiles. It is also illustrated that the increase of Mach number will result in non-uniform entropy profiles with increase in the vicinity of the central regions of the channel. Moreover, generation of entropy in all regions of the domain stages clear growth. By contrast, increasing the Knudsen number has inverse effects such as: uniform entropy profiles and a falling off in entropy generation amount throughout the channel.

  5. MgO melting curve constraints from shock temperature and rarefaction overtake measurements in samples preheated to 2300 K

    Science.gov (United States)

    Fat'yanov, O. V.; Asimow, P. D.

    2014-05-01

    Continuing our effort to obtain experimental constraints on the melting curve of MgO at 100-200 GPa, we extended our target preheating capability to 2300 K. Our new Mo capsule design holds a long MgO crystal in a controlled thermal gradient until impact by a Ta flyer launched at up to 7.5 km/s on the Caltech two-stage light-gas gun. Radiative shock temperatures and rarefaction overtake times were measured simultaneously by a 6-channel VIS/NIR pyrometer with 3 ns time resolution. The majority of our experiments showed smooth monotonic increases in MgO sound speed and shock temperature with pressure from 197 to 243 GPa. The measured temperatures as well as the slopes of the pressure dependences for both temperature and sound speed were in good agreement with those calculated numerically for the solid phase at our peak shock compression conditions. Most observed sound speeds, however, were ~800 m/s higher than those predicted by the model. A single unconfirmed data point at 239 GPa showed anomalously low temperature and sound speed, which could both be explained by partial melting in this experiment and could suggest that the Hugoniot of MgO preheated to 2300 K crosses its melting line just slightly above 240 GPa.

  6. MgO melting curve constraints from shock temperature and rarefaction overtake measurements in samples preheated to 2300 K

    International Nuclear Information System (INIS)

    Fat'yanov, O V; Asimow, P D

    2014-01-01

    Continuing our effort to obtain experimental constraints on the melting curve of MgO at 100-200 GPa, we extended our target preheating capability to 2300 K. Our new Mo capsule design holds a long MgO crystal in a controlled thermal gradient until impact by a Ta flyer launched at up to 7.5 km/s on the Caltech two-stage light-gas gun. Radiative shock temperatures and rarefaction overtake times were measured simultaneously by a 6-channel VIS/NIR pyrometer with 3 ns time resolution. The majority of our experiments showed smooth monotonic increases in MgO sound speed and shock temperature with pressure from 197 to 243 GPa. The measured temperatures as well as the slopes of the pressure dependences for both temperature and sound speed were in good agreement with those calculated numerically for the solid phase at our peak shock compression conditions. Most observed sound speeds, however, were ∼800 m/s higher than those predicted by the model. A single unconfirmed data point at 239 GPa showed anomalously low temperature and sound speed, which could both be explained by partial melting in this experiment and could suggest that the Hugoniot of MgO preheated to 2300 K crosses its melting line just slightly above 240 GPa.

  7. Mesenchymal stem cell-derived microparticles ameliorate peritubular capillary rarefaction via inhibition of endothelial-mesenchymal transition and decrease tubulointerstitial fibrosis in unilateral ureteral obstruction.

    Science.gov (United States)

    Choi, Hoon Young; Lee, Hyun Gyu; Kim, Beom Seok; Ahn, Sun Hee; Jung, Ara; Lee, Mirae; Lee, Jung Eun; Kim, Hyung Jong; Ha, Sung Kyu; Park, Hyeong Cheon

    2015-03-11

    Microparticles (MPs) derived from kidney-derived mesenchymal stem cells (KMSCs) have recently been reported to ameliorate rarefaction of peritubular capillaries (PTC) in ischemic kidneys via delivery of proangiogenic effectors. This study aimed to investigate whether KMSC-derived MPs show anti-fibrotic effects by ameliorating endothelial-to-mesenchymal transition (EndoMT) in human umbilical vein endothelial cells (HUVEC) in vitro and by preserving PTC in kidneys with unilateral ureteral obstruction (UUO) in vivo. MPs isolated from the supernatants of KMSC were co-cultured with HUVEC to assess their in vitro biologic effects on endothelial cells. Mice were treated with MPs via the tail vein after UUO injury to assess their anti-fibrotic and PTC sparing effects. Renal tubulointerstitial damage and inflammatory cell infiltration were examined with Masson's trichrome, F4/80 and α-smooth muscle actin (α-SMA) staining and PTC rarefaction index was determined by CD31 staining. KMSC-derived MPs significantly ameliorated EndoMT and improved in vitro proliferation of TGF-β1 treated HUVEC. In vivo administration of KMSC-derived MPs significantly inhibited EndoMT of PTC endothelial cells and improved PTC rarefaction in UUO kidneys. Furthermore, administration of KMSC-derived MPs inhibited inflammatory cell infiltration as well as tubulointerstitial fibrosis in UUO mice as demonstrated by decreased F4/80 and α-SMA-positive cells and Masson's trichrome staining, respectively. Our results suggest that KMSC-derived MPs ameliorate PTC rarefaction via inhibition of EndoMT and protect against progression of renal damage by inhibiting tubulointerstitial fibrosis.

  8. Compressive and rarefactive dust-ion-acoustic Gardner solitons in a multi-component dusty plasma

    International Nuclear Information System (INIS)

    Ema, S. A.; Ferdousi, M.; Mamun, A. A.

    2015-01-01

    The linear and nonlinear propagations of dust-ion-acoustic solitary waves (DIASWs) in a collisionless four-component unmagnetized dusty plasma system containing nonextensive electrons, inertial negative ions, Maxwellian positive ions, and negatively charged static dust grains have been investigated theoretically. The linear properties are analyzed by using the normal mode analysis and the reductive perturbation method is used to derive the nonlinear equations, namely, the Korteweg-de Vries (K-dV), the modified K-dV (mK-dV), and the Gardner equations. The basic features (viz., polarity, amplitude, width, etc.) of Gardner solitons (GS) are found to exist beyond the K-dV limit and these dust-ion-acoustic GS are qualitatively different from the K-dV and mK-dV solitons. It is observed that the basic features of DIASWs are affected by various plasma parameters (viz., electron nonextensivity, negative-to-positive ion number density ratio, electron-to-positive ion number density ratio, electron-to-positive ion temperature ratio, etc.) of the considered plasma system. The findings of our results obtained from this theoretical investigation may be useful in understanding the nonlinear structures and the characteristics of DIASWs propagating in both space and laboratory plasmas

  9. Imaging evaluation of fetal vascular anomalies

    International Nuclear Information System (INIS)

    Calvo-Garcia, Maria A.; Kline-Fath, Beth M.; Koch, Bernadette L.; Laor, Tal; Adams, Denise M.; Gupta, Anita; Lim, Foong-Yen

    2015-01-01

    Vascular anomalies can be detected in utero and should be considered in the setting of solid, mixed or cystic lesions in the fetus. Evaluation of the gray-scale and color Doppler US and MRI characteristics can guide diagnosis. We present a case-based pictorial essay to illustrate the prenatal imaging characteristics in 11 pregnancies with vascular malformations (5 lymphatic malformations, 2 Klippel-Trenaunay syndrome, 1 venous-lymphatic malformation, 1 Parkes-Weber syndrome) and vascular tumors (1 congenital hemangioma, 1 kaposiform hemangioendothelioma). Concordance between prenatal and postnatal diagnoses is analyzed, with further discussion regarding potential pitfalls in identification. (orig.)

  10. Imaging evaluation of fetal vascular anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Calvo-Garcia, Maria A.; Kline-Fath, Beth M.; Koch, Bernadette L.; Laor, Tal [MLC 5031 Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Adams, Denise M. [Cincinnati Children' s Hospital Medical Center, Department of Pediatrics and Hemangioma and Vascular Malformation Center, Cincinnati, OH (United States); Gupta, Anita [Cincinnati Children' s Hospital Medical Center, Department of Pathology, Cincinnati, OH (United States); Lim, Foong-Yen [Cincinnati Children' s Hospital Medical Center, Pediatric Surgery and Fetal Center of Cincinnati, Cincinnati, OH (United States)

    2015-08-15

    Vascular anomalies can be detected in utero and should be considered in the setting of solid, mixed or cystic lesions in the fetus. Evaluation of the gray-scale and color Doppler US and MRI characteristics can guide diagnosis. We present a case-based pictorial essay to illustrate the prenatal imaging characteristics in 11 pregnancies with vascular malformations (5 lymphatic malformations, 2 Klippel-Trenaunay syndrome, 1 venous-lymphatic malformation, 1 Parkes-Weber syndrome) and vascular tumors (1 congenital hemangioma, 1 kaposiform hemangioendothelioma). Concordance between prenatal and postnatal diagnoses is analyzed, with further discussion regarding potential pitfalls in identification. (orig.)

  11. Bioprinting for vascular and vascularized tissue biofabrication.

    Science.gov (United States)

    Datta, Pallab; Ayan, Bugra; Ozbolat, Ibrahim T

    2017-03-15

    Bioprinting is a promising technology to fabricate design-specific tissue constructs due to its ability to create complex, heterocellular structures with anatomical precision. Bioprinting enables the deposition of various biologics including growth factors, cells, genes, neo-tissues and extra-cellular matrix-like hydrogels. Benefits of bioprinting have started to make a mark in the fields of tissue engineering, regenerative medicine and pharmaceutics. Specifically, in the field of tissue engineering, the creation of vascularized tissue constructs has remained a principal challenge till date. However, given the myriad advantages over other biofabrication methods, it becomes organic to expect that bioprinting can provide a viable solution for the vascularization problem, and facilitate the clinical translation of tissue engineered constructs. This article provides a comprehensive account of bioprinting of vascular and vascularized tissue constructs. The review is structured as introducing the scope of bioprinting in tissue engineering applications, key vascular anatomical features and then a thorough coverage of 3D bioprinting using extrusion-, droplet- and laser-based bioprinting for fabrication of vascular tissue constructs. The review then provides the reader with the use of bioprinting for obtaining thick vascularized tissues using sacrificial bioink materials. Current challenges are discussed, a comparative evaluation of different bioprinting modalities is presented and future prospects are provided to the reader. Biofabrication of living tissues and organs at the clinically-relevant volumes vitally depends on the integration of vascular network. Despite the great progress in traditional biofabrication approaches, building perfusable hierarchical vascular network is a major challenge. Bioprinting is an emerging technology to fabricate design-specific tissue constructs due to its ability to create complex, heterocellular structures with anatomical precision

  12. Vascular dysfunction in preeclampsia.

    Science.gov (United States)

    Brennan, Lesley J; Morton, Jude S; Davidge, Sandra T

    2014-01-01

    Preeclampsia is a complex disorder which affects an estimated 5% of all pregnancies worldwide. It is diagnosed by hypertension in the presence of proteinuria after the 20th week of pregnancy and is a prominent cause of maternal morbidity and mortality. As delivery is currently the only known treatment, preeclampsia is also a leading cause of preterm delivery. Preeclampsia is associated with maternal vascular dysfunction, leading to serious cardiovascular risk both during and following pregnancy. Endothelial dysfunction, resulting in increased peripheral resistance, is an integral part of the maternal syndrome. While the cause of preeclampsia remains unknown, placental ischemia resulting from aberrant placentation is a fundamental characteristic of the disorder. Poor placentation is believed to stimulate the release of a number of factors including pro- and antiangiogenic factors and inflammatory activators into the maternal systemic circulation. These factors are critical mediators of vascular function and impact the endothelium in distinctive ways, including enhanced endothelial oxidative stress. The mechanisms of action and the consequences on the maternal vasculature will be discussed in this review. © 2013 John Wiley & Sons Ltd.

  13. Characteristics of Cerebral Blood Flow in Vascular Dementia using SPM Analysis Compared to Normal Control and Alzheimer's Dementia

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Do Young; Park, Kyung Won; Kim, Jae Woo [College of Medicine, Univ. of Donga, Busan (Korea, Republic of)

    2003-07-01

    Cerebral perfusion pattern of vascular dementia (VD) was not well established and overlap of cerebral perfusion pattern was reported between VD and Alzheimer's dementia (AD). The aim of this study is to assess the specific patterns of SPECT finding in VD compared with normal control subjects and to disclose differences of cerebral blood flow between subjects with VD and AD were investigated using statistic parametric mapping analysis. Thirty-two VD (mean age ; 67.86.4 years, mean CDR ; 0.980.27), 51 AD (mean age ; 71.47.2 years, CDR ; 1.160.47), which were matched for age and severity of dementia, and 30 normal control subjects (mean age ; 60.17.7 years) participated in this study. The Tc-99m HMPAO brain perfusion SPECT data were analyzed by SPM99. The SPECT data of the patients with VD were compared to those of the control subjects and then compared to the patients with AD. SPM analysis of the SPECT image showed significant perfusion deficits in the both frontal (both cingulate gyrus, both inferior frontal gyrus, B no.47, right frontal rectal gyrus, left frontal subcallosal gyrus, B no.25), both temporal (right insula, B no.13, left superior temporal gyrus, left parahippocampal gyrus, B no.35), occipital (occipital lingual gyrus), right corpus callosum and right cerebellar tonsil regions in subjects with VD compared with normal control subjects (uncorrected p<0.01). Comparison of the two dementia groups (uncorrected p<0.01) revealed significant hypoperfusion in both parietal posterior central gyrus, right inferior frontal gyrus (B no.47), left insula, right thalamus (ventral lateral nucleus), right claustrum and right occipital cuneus regions in VD group compared with AD. There were no typical confined regional hypoperfusion areas but scattered multiple perfusion deficits in VD compared AD. These findings may be helpful to reflect the pathophysiological mechanisms of VD and to disclose differences of cerebral blood flow between subjects with VD and AD.

  14. Proatherogenic pathways leading to vascular calcification

    International Nuclear Information System (INIS)

    Mazzini, Michael J.; Schulze, P. Christian

    2006-01-01

    Cardiovascular disease is the leading cause of morbidity and mortality in the western world and atherosclerosis is the major common underlying disease. The pathogenesis of atherosclerosis involves local vascular injury, inflammation and oxidative stress as well as vascular calcification. Vascular calcification has long been regarded as a degenerative process leading to mineral deposition in the vascular wall characteristic for late stages of atherosclerosis. However, recent studies identified vascular calcification in early stages of atherosclerosis and its occurrence has been linked to clinical events in patients with cardiovascular disease. Its degree correlates with local vascular inflammation and with the overall impact and the progression of atherosclerosis. Over the last decade, diverse and highly regulated molecular signaling cascades controlling vascular calcification have been described. Local and circulating molecules such as osteopontin, osteoprogerin, leptin and matrix Gla protein were identified as critical regulators of vascular calcification. We here review the current knowledge on molecular pathways of vascular calcification and their relevance for the progression of cardiovascular disease

  15. 肝内门腔分流术支架与血管支架组织成分的对比研究%Experimental comparison study of the tissue characteristics in transjugular intrahepalic portosystemic shunt and vascular stent

    Institute of Scientific and Technical Information of China (English)

    卢勤; 魏晓莹; 滕皋军; 安艳丽; 邓钢; 方文; 朱光宇; 牛焕章; 余辉; 李国昭; 王甄

    2009-01-01

    Objective To investigate the tissue characteristics within vascular stent and transjugular intrahepatic portosystemic shunt(TIPS)on swine and to provide more information for the understanding and prevention of vascular stent and TIPS restenosis.Methods Animal models for TIPS were built in 6 swine and vascular stents were implanted in iliac veins simultaneouly.14-28 days after the operation.the 6 swine were killed to remove the TIPS and vascular stent and the pathological examinations were performed on the tissues within the shunt and stent.The similarities and difierences of the tissues within the shunt and stent were analvzed with Kruskal Wallis test. Results Restenosis of TIPS occurred in 4 models and complete occlusion were seen in 2,while all vascular stents were patent and coated with a thin layer of intimal tissueElectron micmscopic results showed that the tissues in restenotic TIPS were loose and with more extra matrix and fibers.and less smooth muscle,fibroblastic and myofibroblastic cells with different and irregular shape and rich secretory granules.The tissues in patent,TIPS contained more extra fibers,smooth muscle and fibmblastic cells with normal organdie.The intimal tissues in vascular stent contained more fibers and fibroblasts cells.less smooth muscle cells.On immunohistoehemical staining,the tissues in restenotlc and Datent TIPS as well as the intimal tissues in vascular stent had strong positive expression for anti-SMCactin-α.the expression were gradually weakened for PCNA,the intimal tissues in vascular stent had a strong positive expression for vimentin,while the expression of the tissues in restenotic and patent TIPS were weakened gradually.For myoglobulin,the tissues in restenotic TIPS had weakly positive expression,the expression in patent TIPS and vascular stent were almost negative. Western blot results for TGF-β showed that the absorbance ratios of the intima tissues in vascular stent,normal vascular tissues,normal liver tissues

  16. The vascular surgery workforce: a survey of consultant vascular surgeons in the UK, 2014.

    Science.gov (United States)

    Harkin, D W; Beard, J D; Shearman, C P; Wyatt, M G

    2015-04-01

    The purpose of this study was to describe the demographics, training, and practice characteristics of consultant vascular surgeons across the UK to provide an assessment of current, and inform future prediction of workforce needs. A questionnaire was developed using a modified Delphi process to generate questionnaire items. The questionnaire was emailed to all consultant vascular surgeons (n = 450) in the UK who were members of the Vascular Society of Great Britain & Ireland. 352 consultant vascular surgeons from 95 hospital trusts across the UK completed the survey (78% response rate). The mean age was 50.6 years old, the majority (62%) were mid-career, but 24% were above the age of 55. Currently, 92% are men and only 8% women. 93% work full-time, with 60% working >50 hours, and 21% working >60 hours per week. The average team was 5 to 6 (range 2-10) vascular surgeons, with 23% working in a large team of ≥8. 17% still work in small teams of ≤3. Over 90% of consultant vascular surgeons perform the major index vascular surgery procedures (aneurysm repair, carotid endarterectomy, infra-inguinal bypass, amputation). While 84% perform standard endovascular abdominal aortic aneurysm repair (EVAR), <50% perform more complex endovascular aortic therapy. The majority of vascular surgeons "like their job" (85%) and are "satisfied" (69%) with their job. 34% of consultant vascular surgeons indicated they were "extremely likely" to retire within the next 10 years. This study provides the first detailed analysis of the new specialty of vascular surgery as practiced in the UK. There is a need to plan for a significant expansion in the consultant vascular surgeon workforce in the UK over the next 10 years to maintain the status quo. Copyright © 2014 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

  17. Open and endovascular aneurysm repair in the Society for Vascular Surgery Vascular Quality Initiative.

    Science.gov (United States)

    Spangler, Emily L; Beck, Adam W

    2017-12-01

    The Society for Vascular Surgery Vascular Quality Initiative is a patient safety organization and a collection of procedure-based registries that can be utilized for quality improvement initiatives and clinical outcomes research. The Vascular Quality Initiative consists of voluntary participation by centers to collect data prospectively on all consecutive cases within specific registries which physicians and centers elect to participate. The data capture extends from preoperative demographics and risk factors (including indications for operation), through the perioperative period, to outcomes data at up to 1-year of follow-up. Additionally, longer-term follow-up can be achieved by matching with Medicare claims data, providing long-term longitudinal follow-up for a majority of patients within the Vascular Quality Initiative registries. We present the unique characteristics of the Vascular Quality Initiative registries and highlight important insights gained specific to open and endovascular abdominal aortic aneurysm repair. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Vascular grading of angiogenesis

    DEFF Research Database (Denmark)

    Hansen, S; Grabau, D A; Sørensen, Flemming Brandt

    2000-01-01

    The study aimed to evaluate the prognostic value of angiogenesis by vascular grading of primary breast tumours, and to evaluate the prognostic impact of adding the vascular grade to the Nottingham Prognostic Index (NPI). The investigation included 836 patients. The median follow-up time was 11...... years and 4 months. The microvessels were immunohistochemically stained by antibodies against CD34. Angiogenesis was graded semiquantitatively by subjective scoring into three groups according to the expected number of microvessels in the most vascular tumour area. The vascular grading between observers...... for 24% of the patients, who had a shift in prognostic group, as compared to NPI, and implied a better prognostic dissemination. We concluded that the angiogenesis determined by vascular grading has independent prognostic value of clinical relevance for patients with breast cancer....

  19. Vascular grading of angiogenesis

    DEFF Research Database (Denmark)

    Hansen, S; Grabau, D A; Sørensen, Flemming Brandt

    2000-01-01

    The study aimed to evaluate the prognostic value of angiogenesis by vascular grading of primary breast tumours, and to evaluate the prognostic impact of adding the vascular grade to the Nottingham Prognostic Index (NPI). The investigation included 836 patients. The median follow-up time was 11...... years and 4 months. The microvessels were immunohistochemically stained by antibodies against CD34. Angiogenesis was graded semiquantitatively by subjective scoring into three groups according to the expected number of microvessels in the most vascular tumour area. The vascular grading between observers...... impact for 24% of the patients, who had a shift in prognostic group, as compared to NPI, and implied a better prognostic dissemination. We concluded that the angiogenesis determined by vascular grading has independent prognostic value of clinical relevance for patients with breast cancer....

  20. Vascular Access in Children

    International Nuclear Information System (INIS)

    Krishnamurthy, Ganesh; Keller, Marc S.

    2011-01-01

    Establishment of stable vascular access is one of the essential and most challenging procedures in a pediatric hospital. Many clinical specialties provide vascular service in a pediatric hospital. At the top of the “expert procedural pyramid” is the pediatric interventional radiologist, who is best suited and trained to deliver this service. Growing awareness regarding the safety and high success rate of vascular access using image guidance has led to increased demand from clinicians to provide around-the-clock vascular access service by pediatric interventional radiologists. Hence, the success of a vascular access program, with the pediatric interventional radiologist as the key provider, is challenging, and a coordinated multidisciplinary team effort is essential for success. However, there are few dedicated pediatric interventional radiologists across the globe, and also only a couple of training programs exist for pediatric interventions. This article gives an overview of the technical aspects of pediatric vascular access and provides useful tips for obtaining vascular access in children safely and successfully using image guidance.

  1. Pediatric vascular access

    International Nuclear Information System (INIS)

    Donaldson, James S.

    2006-01-01

    Pediatric interventional radiologists are ideally suited to provide vascular access services to children because of inherent safety advantages and higher success from using image-guided techniques. The performance of vascular access procedures has become routine at many adult interventional radiology practices, but this service is not as widely developed at pediatric institutions. Although interventional radiologists at some children's hospitals offer full-service vascular access, there is little or none at others. Developing and maintaining a pediatric vascular access service is a challenge. Interventionalists skilled in performing such procedures are limited at pediatric institutions, and institutional support from clerical staff, nursing staff, and technologists might not be sufficiently available to fulfill the needs of such a service. There must also be a strong commitment by all members of the team to support such a demanding service. There is a slippery slope of expected services that becomes steeper and steeper as the vascular access service grows. This review is intended primarily as general education for pediatric radiologists learning vascular access techniques. Additionally, the pediatric or adult interventional radiologist seeking to expand services might find helpful tips. The article also provides education for the diagnostic radiologist who routinely interprets radiographs containing vascular access devices. (orig.)

  2. Vascular malformations in pediatrics

    International Nuclear Information System (INIS)

    Reith, W.; Shamdeen, M.G.

    2003-01-01

    Vascular malformations are the cause of nearly all non-traumatic intracranial hemorrhage in children beyond the neonatal stage. Therefore, any child presenting with spontaneous intracranial hemorrhage should be evaluated for child abuse and for vascular malformations. Intracerebral malformations of the cerebral vasculature include vein of Galen malformations, arteriovenous malformation (AVM), cavernomas, dural arteriovenous fistulas, venous anomalies (DVA), and capillary teleangiectasies. Although a few familial vascular malformation have been reported, the majority are sporadic. Clinical symptoms, diagnostic and therapeutic options are discussed. (orig.) [de

  3. Uterine Vascular Lesions

    Science.gov (United States)

    Vijayakumar, Abhishek; Srinivas, Amruthashree; Chandrashekar, Babitha Moogali; Vijayakumar, Avinash

    2013-01-01

    Vascular lesions of the uterus are rare; most reported in the literature are arteriovenous malformations (AVMs). Uterine AVMs can be congenital or acquired. In recent years, there has been an increasing number of reports of acquired vascular lesions of the uterus following pregnancy, abortion, cesarean delivery, and curettage. It can be seen from these reports that there is confusion concerning the terminology of uterine vascular lesions. There is also a lack of diagnostic criteria and management guidelines, which has led to an increased number of unnecessary invasive procedures (eg, angiography, uterine artery embolization, hysterectomy for abnormal vaginal bleeding). This article familiarizes readers with various vascular lesions of the uterus and their management. PMID:24340126

  4. Magnetic resonance vascular imaging

    International Nuclear Information System (INIS)

    Axel, L

    1989-01-01

    The basis principles of MRI are reviewed in order to understand how blood flow effects arise in conventional imaging. Then some of the ways these effects have ben used in MRI techniques specifically designed for vascular imaging, are considered. (author)

  5. Impaired vascular reactivity in patients with chronic kidney disease

    DEFF Research Database (Denmark)

    Tetzner, Fabian; Scholze, Alexandra; Wittstock, Antje

    2008-01-01

    Patients with chronic kidney disease (CKD) show increased cardiovascular morbidity. We hypothesized that vascular properties which can be routinely evaluated noninvasively are related to different stages of CKD and their clinical and biochemical characteristics....

  6. Overview of vascular disease

    International Nuclear Information System (INIS)

    Bisset, G.S. III

    1998-01-01

    Vascular disease in the pediatric population is a poorly understood process which is often underestimated in its incidence. The common beginnings of such ubiquitous diseases as atherosclerosis manifest themselves at a cellular level shortly after birth. Other common systemic disorders, including congestive heart failure and sepsis, are also intricately associated with dysfunctional vasculature. Progress in the understanding of normal and pathophysiologic processes within the vascular system begins with the 'control center' - the endothelial cell. The purpose of this review is to consolidate a body of knowledge on the processes that occur at the cellular level within the blood vessel wall, and to simplify the understanding of how imbalances in these physiologic parameters result in vascular disease. (orig.)

  7. Optical coherence tomography angiography indicates associations of the retinal vascular network and disease activity in multiple sclerosis.

    Science.gov (United States)

    Feucht, Nikolaus; Maier, Mathias; Lepennetier, Gildas; Pettenkofer, Moritz; Wetzlmair, Carmen; Daltrozzo, Tanja; Scherm, Pauline; Zimmer, Claus; Hoshi, Muna-Miriam; Hemmer, Bernhard; Korn, Thomas; Knier, Benjamin

    2018-01-01

    Patients with multiple sclerosis (MS) and clinically isolated syndrome (CIS) may show alterations of retinal layer architecture as measured by optical coherence tomography. Little is known about changes in the retinal vascular network during MS. To characterize retinal vessel structures in patients with MS and CIS and to test for associations with MS disease activity. In all, 42 patients with MS or CIS and 50 healthy controls underwent retinal optical coherence tomography angiography (OCT-A) with analysis of the superficial and deep vascular plexuses and the choriocapillaries. We tested OCT-A parameters for associations with retinal layer volumes, history of optic neuritis (ON), and the retrospective disease activity. Inner retinal layer volumes correlated positively with the density of both the superficial and deep vascular plexuses. Eyes of MS/CIS patients with a history of ON revealed reduced vessel densities of the superficial and deep vascular plexuses as compared to healthy controls. Higher choriocapillary vessel densities were associated with ongoing inflammatory disease activity during 24 months prior to OCT-A examination in MS and CIS patients. Optic neuritis is associated with rarefaction of the superficial and deep retinal vessels. Alterations of the choriocapillaries might be linked to disease activity in MS.

  8. Diffuse and vascular hepatic diseases

    International Nuclear Information System (INIS)

    Kreimeyer, S.; Grenacher, L.

    2011-01-01

    In addition to focal liver lesions, diffuse and vascular disorders of the liver represent a wide spectrum of liver diseases which are from the radiological point of view often difficult or nearly impossible to diagnose. Classical diagnostic methods are computed tomography and magnetic resonance imaging in addition to ultrasound. Diffuse parenchymal damage caused by diseases of various etiologies is therefore difficult to evaluate because it often lacks characteristic morphological features. For hepatic steatosis, hemochromatosis/siderosis as an example of a diffuse storage disease and sarcoidosis and candidiasis as infectious/inflammatory diseases, an image-based diagnosis is appropriate in some cases. For most diffuse liver diseases, however only nonspecific changes are visualized. Vascular pathologies of the liver, such as the Budd-Chiari syndrome and portal vein thrombosis, however, can usually be diagnosed very clearly using radiology and there is also a very effective interventional radiological treatment. Chronic diseases very often culminate in liver cirrhosis which is highly associated with an increased risk of liver cancer. (orig.) [de

  9. Renal posttransplant's vascular complications

    Directory of Open Access Journals (Sweden)

    Bašić Dragoslav

    2003-01-01

    Full Text Available INTRODUCTION Despite high graft and recipient survival figures worldwide today, a variety of technical complications can threaten the transplant in the postoperative period. Vascular complications are commonly related to technical problems in establishing vascular continuity or to damage that occurs during donor nephrectomy or preservation [13]. AIM The aim of the presenting study is to evaluate counts and rates of vascular complications after renal transplantation and to compare the outcome by donor type. MATERIAL AND METHODS A total of 463 kidneys (319 from living related donor LD and 144 from cadaveric donor - CD were transplanted during the period between June 1975 and December 1998 at the Urology & Nephrology Institute of Clinical Centre of Serbia in Belgrade. Average recipients' age was 33.7 years (15-54 in LD group and 39.8 (19-62 in CD group. Retrospectively, we analyzed medical records of all recipients. Statistical analysis is estimated using Hi-squared test and Fischer's test of exact probability. RESULTS Major vascular complications including vascular anastomosis thrombosis, internal iliac artery stenosis, internal iliac artery rupture obliterant vasculitis and external iliac vein rupture were analyzed. In 25 recipients (5.4% some of major vascular complications were detected. Among these cases, 22 of them were from CD group vs. three from LD group. Relative rate of these complications was higher in CD group vs. LD group (p<0.0001. Among these complications dominant one was vascular anastomosis thrombosis which occurred in 18 recipients (17 from CD vs. one from LD. Of these recipients 16 from CD lost the graft, while the rest of two (one from each group had lethal outcome. DISCUSSION Thrombosis of renal allograft vascular anastomosis site is the most severe complication following renal transplantation. In the literature, renal allograft thrombosis is reported with different incidence rates, from 0.5-4% [14, 15, 16]. Data from the

  10. Vascular gastric anomalies as a cause of relapsing bleeding

    Directory of Open Access Journals (Sweden)

    Golubović Gradimir

    2008-01-01

    Full Text Available Background. Although relatively rare, gastric vascular anomalies can be recognized as a source of both chronic and acute blood loss, most often presenting as long term iron deficiency anemia, rarely as severe acute gastrointestinal bleeding. Case report. We present five patients with various gastric vascular anomalies, diagnosed during the year of 2003. in the Clinical Hospital Center Zemun. The diagnosis was based on endoscopic appearances, clinical history and characteristic histological findings. Gastric vascular anomalies presented in our review were: portal hypertensive gastropathy, gastric antral vascular ectasia, angiodysplasia, hereditary hemorrhagic telangiectasia and Dieulafoy lesion. The used treatment modalities included surgery and various endoscopic techniques (schlerotherapy, argon plasma coagulation. Conclusion. Patients presented with chronic iron deficiency anemia or acute and recurrent gastrointestinal hemorrhage should be considered as having one of gastric vascular anomalies.

  11. Major Vascular Neurocognitive Disorder: A Reappraisal to Vascular Dementia

    Directory of Open Access Journals (Sweden)

    Emre Kumral

    2017-03-01

    Full Text Available Major vascular neurocognitive disorder (NCD is the second leading form of dementia after Alzheimer’s disease, accounting for 17-20% of all dementias. Vascular NCD is a progressive disease caused by reduced cerebral blood flow related to multiple large volume or lacunar infarcts that induce a sudden onset and stepwise decline in cognitive abilities. Despite its prevalence and clinical importance, there is still controversy in the terminology of vascular NCD. Only after the release of Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5 (2013 did the American Psychiatric Association define vascular dementia as “major vascular NCD”. This review includes an overview of risk factors, pathophysiology, types, diagnostic and clinical features of major vascular NCD, and current treatment options of vascular NCD regarding to DSM-5 criteria

  12. Plant Vascular Biology 2010

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Biao

    2014-11-17

    This grant supported the Second International Conference on Plant Vascular Biology (PVB 2010) held July 24-28, 2010 on the campus of Ohio State University, Columbus, Ohio. Biao Ding (Ohio State University; OSU) and David Hannapel (Iowa State University; ISU) served as co-chairs of this conference. Biao Ding served as the local organizer. PVB is defined broadly here to include studies on the biogenesis, structure and function of transport systems in plants, under conditions of normal plant growth and development as well as of plant interactions with pathogens. The transport systems cover broadly the xylem, phloem, plasmodesmata and vascular cell membranes. The PVB concept has emerged in recent years to emphasize the integrative nature of the transport systems and approaches to investigate them.

  13. Vascular cognitive impairment

    Directory of Open Access Journals (Sweden)

    N.V. Vakhnina

    2014-01-01

    Full Text Available Vascular pathology of the brain is the second most common cause of cognitive impairment after Alzheimer's disease. The article describes the modern concepts of etiology, pathogenetic mechanisms, clinical features and approaches to diagnosis and therapy of vascular cognitive impairment (VCI. Cerebrovascular accident, chronic cerebral circulatory insufficiency and their combination, sometimes in combination with a concomitant neurodegenerative process, are shown to be the major types of brain lesions leading to VCI. The clinical presentation of VCI is characterized by the neuropsychological status dominated by impairment of the executive frontal functions (planning, control, attention in combination with focal neurological symptoms. The diagnosis is based on comparing of the revealed neuropsychological and neurological features with neuroimaging data. Neurometabolic, acetylcholinergic, glutamatergic, and other vasoactive drugs and non-pharmacological methods are widely used to treat VCI. 

  14. Vascular Surgery and Robotics

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    Indrani Sen

    2016-01-01

    Full Text Available The application of robotics to Vascular surgery has not progressed as rapidly as of endovascular technology, but this is changing with the amalgamation of these two fields. The advent of Endovascular robotics is an exciting field which overcomes many of the limitations of endovascular therapy like vessel tortuosity and operator fatigue. This has much clinical appeal for the surgeon and hold significant promise of better patient outcomes. As with most newer technological advances, it is still limited by cost and availability. However, this field has seen some rapid progress in the last decade with the technology moving into the clinical realm. This review details the development of robotics, applications, outcomes, advantages, disadvantages and current advances focussing on Vascular and Endovascular robotics

  15. Vascular lumen formation.

    Science.gov (United States)

    Lammert, Eckhard; Axnick, Jennifer

    2012-04-01

    The vascular system developed early in evolution. It is required in large multicellular organisms for the transport of nutrients, oxygen, and waste products to and from tissues. The vascular system is composed of hollow tubes, which have a high level of complexity in vertebrates. Vasculogenesis describes the de novo formation of blood vessels, e.g., aorta formation in vertebrate embryogenesis. In contrast, angiogenesis is the formation of blood vessels from preexisting ones, e.g., sprouting of intersomitic blood vessels from the aorta. Importantly, the lumen of all blood vessels in vertebrates is lined and formed by endothelial cells. In both vasculogenesis and angiogenesis, lumen formation takes place in a cord of endothelial cells. It involves a complex molecular mechanism composed of endothelial cell repulsion at the cell-cell contacts within the endothelial cell cords, junctional rearrangement, and endothelial cell shape change. As the vascular system also participates in the course of many diseases, such as cancer, stroke, and myocardial infarction, it is important to understand and make use of the molecular mechanisms of blood vessel formation to better understand and manipulate the pathomechanisms involved.

  16. Rarefaction Effects in Hypersonic Aerodynamics

    Science.gov (United States)

    Riabov, Vladimir V.

    2011-05-01

    The Direct Simulation Monte-Carlo (DSMC) technique is used for numerical analysis of rarefied-gas hypersonic flows near a blunt plate, wedge, two side-by-side plates, disk, torus, and rotating cylinder. The role of various similarity parameters (Knudsen and Mach numbers, geometrical and temperature factors, specific heat ratios, and others) in aerodynamics of the probes is studied. Important kinetic effects that are specific for the transition flow regime have been found: non-monotonic lift and drag of plates, strong repulsive force between side-by-side plates and cylinders, dependence of drag on torus radii ratio, and the reverse Magnus effect on the lift of a rotating cylinder. The numerical results are in a good agreement with experimental data, which were obtained in a vacuum chamber at low and moderate Knudsen numbers from 0.01 to 10.

  17. Relación entre características antropométricas y variables de riesgo vascular en diabéticos tipo 2 Relationship between anthropometric characteristics and its repercussion in Type-2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Karelia Zubizarreta Peinado

    2012-06-01

    Full Text Available La interrelación existente entre obesidad y diabetes mellitus tipo 2 tiene gran importancia clínico-epidemiológica. Se propone como objetivo evaluar en diabéticos tipo 2 la relación entre las características antropométricas y el nivel de riesgo de variables clínicas y bioquímicas. Se estudiaron 120 pacientes, edades 40 a 79 años, de la consulta de diabetes del Hospital "Hermanos Ameijeiras¨, entre octubre del 2009 y septiembre del 2010. Se evaluaron antecedentes, complementarios, y se realizó examen clínico general. Se determinaron índice de masa corporal (IMC, circunferencia abdominal (CA, tensión arterial (TA, parámetros glucémicos (glucemia en ayunas, postprandial, hemoglobina glucosilada, lípidicos (colesterol, triglicéridos, HDL-C, LDL-C, así como ácido úrico y microalbuminuria y se clasificaron según riesgo vascular en bajo, moderado y alto. Se consideró alto riesgo la obesidad (IMC = de 30 kg/m²sc y CA aumentada (CAA hombres >102 cm y mujeres > 88 y se relacionaron con el nivel de riesgo predeterminado para el resto de las variables. Los resultados se analizaron estadísticamente con significación de p The interrelation between obesity and type-2 diabetes mellitus is very important from the clinical and epidemiological view points. This study was aimed at assessing the association between vascular risk and anthropometric variables in patients with type-2 diabetes mellitus, where the body-mass index and the abdominal size were evaluated in relation to the presence of chronic vascular complications in these patients. One hundred twenty (120 patients from 40 to 79 years old, attending to the diabetes mellitus office at “Hermanos Ameijeiras” University Hospital from October 2009 to September 2010 were included in the study considering the medical history, complementary and general clinical examinations. Body-mass index, abdominal size (AS, insulinemia and C-peptide were also determined; (IMC ≥ de 30 kg/m2 sc

  18. Vascular remodeling and mineralocorticoids.

    Science.gov (United States)

    Weber, K T; Sun, Y; Campbell, S E; Slight, S H; Ganjam, V K

    1995-01-01

    Circulating mineralocorticoid hormones are so named because of their important homeostatic properties that regulate salt and water balance via their action on epithelial cells. A broader range of functions in nonclassic target cellular sites has been proposed for these steroids and includes their contribution to wound healing following injury. A chronic, inappropriate (relative to intravascular volume and dietary sodium intake) elevation of these circulating hormones evokes a wound healing response in the absence of tissue injury--a wound healing response gone awry. The adverse remodeling of vascularized tissues seen in association with chronic mineralocorticoid excess is the focus of this review.

  19. The making of indigenous vascular prosthesis

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    Madathipat Unnikrishnan

    2016-01-01

    Full Text Available Background & objectives: Vascular illnesses are on the rise in India, due to increase in lifestyle diseases and demographic transition, requiring intervention to save life, organ or limbs using vascular prosthesis. The aim of this study was to develop indigenous large diameter vascular graft for treatment of patients with vascular pathologies. Methods: The South India Textile Research Association, at Coimbatore, Tamil Nadu, India, developed seamless woven polyester (Polyethylene terephthalate graft at its research wing. Further characterization and testing followed by clinical trials were conducted at Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India. Fifteen in vivo experiments were carried out in 1992-1994 in pigs as animal model. Controlled (phase I clinical trial in ten patients was performed along with control graft. Thereafter, phase II trial involved 22 patients who underwent multi-centre clinical trial in four centres across India. Results: Laboratory testing showed that polyester graft was non-toxic, non-leeching and non-haemolytic with preserved long-term quality, further confirming in pigs by implanting in thoracic aorta, comparable to control Dacron grafts. Perigraft incorporation and smooth neointima formation which are prime features of excellent healing characteristics, were noted at explantation at planned intervals. Subsequently in the phase I and II clinical trials, all patients had excellent recovery without mortality or device-related adverse events. Patients receiving the test graft were followed up for 10 and 5 years, respectively. Serial clinical, duplex scans and CT angiograms performed periodically confirmed excellent graft performance. Interpretation & conclusions: Indigenously developed Chitra vascular graft was comparable to commercially available Dacron graft, ready for clinical use at affordable cost to patients as against costly imported grafts.

  20. Interventional vascular radiology

    International Nuclear Information System (INIS)

    Yune, H.Y.

    1984-01-01

    The papers published during this past year in the area of interventional vascular radiology presented some useful modifications and further experiences both in the area of thromboembolic therapy and in dilation and thrombolysis, but no new techniques. As an introductory subject, an excellent monograph reviewing the current spectrum of pharmacoangiography was presented in Radiographics. Although the presented material is primarily in diagnostic application of various pharmacologic agents used today to facilitate demonstration of certain diagnostic criteria of various disease processes, both vasodilatory and vasoconstrictive reaction to these agents are widely used in various therapeutic vascular procedures. This monograph should be reviewed by every angiographer whether or not he or she performs interventional procedures, and it would be very convenient to have this table available in the angiography suite. In a related subject, Bookstein and co-workers have written an excellent review concerning pharmacologic manipulations of various blood coagulative parameters during angiography. Understanding the proper method of manipulation of the bloodclotting factors during angiography, and especially during interventional angiography, is extremely important. Particularly, the method of manipulating the coagulation with the use of heparin and protamine and modification of the platelet activity by using aspirin and dipyridamole are succinctly reviewed. The systemic and selective thrombolytic activities of streptokianse are also discussed

  1. LASER TREATMENT OF BENIGN CUTANEOUS VASCULAR LESIONS

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    Uroš Ahčan

    2004-07-01

    Full Text Available Background. Congenital and acquired vascular lesions of the skin and subcutis are a common health problem from aesthetic and also from psycho-social point of view. However, recent advances in laser technology have enabled an efficient and safe treatment. This study presents our experience with treatment of cutaneous vascular lesions using modern laser systems. Most common benign cutaneous vascular lesions are described.Patients and methods. In years 2002 and 2003, 109 patients, 4 to 80 (mean 39 years old, Fitzpatrick skin type 1–4, with 210 benign cutaneous vascular lesions were treated using the Dualis VP® laser system (Fotona, Slovenia which incorporates the KTP and Nd:YAG lasers. Vascular lesions in the upper layers of the skin with diameter up to 1 mm were treated with the KTP laser (wavelength 532 nm. For larger vessels in deeper layer we used the Nd:YAG laser (wavelength 1064 nm. Patients graded the pain during treatment on a scale of 1–10. Clinical outcomes were evaluated 1–3 months after the last treatment: according to the percentage of clearance of the lesion compared to the adjacent normal skin and for the presence of adverse effects. According to these criteria each lesion was assigned a score: poor (0–25%, fair (26–50%, good (51–75%, excellent (76–100%.Results. Immediate response after application of a laser beam with proper characteristics was whitish-grey discoloration of treated area. Treatment results after 1–3 months were excellent in 48.1%, good 40.9%, fair in 8.6% and poor in 2.4%. Patients without prior anaesthesia graded pain during treatment from 1 to 8 (mean 4.0 and patients with EMLA® anaesthesia from 1 to 6 (mean 2.6. Side effects were frequent but minimal and transient. Erythema disappeared in several days after treatment while crusting persisted for 14 days. 3 permanent hyperpigmentations, 2 permanent hypopigmentations, 2 hypertrophic scars and 1 beam sized atrophic scar were detected at last follow

  2. Vascular Remodeling in Experimental Hypertension

    Directory of Open Access Journals (Sweden)

    Norma R. Risler

    2005-01-01

    Full Text Available The basic hemodynamic abnormality in hypertension is an increased peripheral resistance that is due mainly to a decreased vascular lumen derived from structural changes in the small arteries wall, named (as a whole vascular remodeling. The vascular wall is an active, flexible, and integrated organ made up of cellular (endothelial cells, smooth muscle cells, adventitia cells, and fibroblasts and noncellular (extracellular matrix components, which in a dynamic way change shape or number, or reorganize in response to physiological and pathological stimuli, maintaining the integrity of the vessel wall in physiological conditions or participating in the vascular changes in cardiovascular diseases such as hypertension. Research focused on new signaling pathways and molecules that can participate in the mechanisms of vascular remodeling has provided evidence showing that vascular structure is not only affected by blood pressure, but also by mechanisms that are independent of the increased pressure. This review will provide an overview of the evidence, explaining some of the pathophysiologic mechanisms participating in the development of the vascular remodeling, in experimental models of hypertension, with special reference to the findings in spontaneously hypertensive rats as a model of essential hypertension, and in fructose-fed rats as a model of secondary hypertension, in the context of the metabolic syndrome. The understanding of the mechanisms producing the vascular alterations will allow the development of novel pharmacological tools for vascular protection in hypertensive disease.

  3. Vascular pattern formation in plants.

    Science.gov (United States)

    Scarpella, Enrico; Helariutta, Ykä

    2010-01-01

    Reticulate tissue systems exist in most multicellular organisms, and the principles underlying the formation of cellular networks have fascinated philosophers, mathematicians, and biologists for centuries. In particular, the beautiful and varied arrangements of vascular tissues in plants have intrigued mankind since antiquity, yet the organizing signals have remained elusive. Plant vascular tissues form systems of interconnected cell files throughout the plant body. Vascular cells are aligned with one another along continuous lines, and vascular tissues differentiate at reproducible positions within organ environments. However, neither the precise path of vascular differentiation nor the exact geometry of vascular networks is fixed or immutable. Several recent advances converge to reconcile the seemingly conflicting predictability and plasticity of vascular tissue patterns. A control mechanism in which an apical-basal flow of signal establishes a basic coordinate system for body axis formation and vascular strand differentiation, and in which a superimposed level of radial organizing cues elaborates cell patterns, would generate a reproducible tissue configuration in the context of an underlying robust, self-organizing structure, and account for the simultaneous regularity and flexibility of vascular tissue patterns. Copyright 2010 Elsevier Inc. All rights reserved.

  4. Additive Manufacturing of Vascular Grafts and Vascularized Tissue Constructs.

    Science.gov (United States)

    Elomaa, Laura; Yang, Yunzhi Peter

    2017-10-01

    There is a great need for engineered vascular grafts among patients with cardiovascular diseases who are in need of bypass therapy and lack autologous healthy blood vessels. In addition, because of the severe worldwide shortage of organ donors, there is an increasing need for engineered vascularized tissue constructs as an alternative to organ transplants. Additive manufacturing (AM) offers great advantages and flexibility of fabrication of cell-laden, multimaterial, and anatomically shaped vascular grafts and vascularized tissue constructs. Various inkjet-, extrusion-, and photocrosslinking-based AM techniques have been applied to the fabrication of both self-standing vascular grafts and porous, vascularized tissue constructs. This review discusses the state-of-the-art research on the use of AM for vascular applications and the key criteria for biomaterials in the AM of both acellular and cellular constructs. We envision that new smart printing materials that can adapt to their environment and encourage rapid endothelialization and remodeling will be the key factor in the future for the successful AM of personalized and dynamic vascular tissue applications.

  5. Inter-arm systolic blood pressure differences, relations with future vascular events and mortality in patients with and without manifest vascular disease

    NARCIS (Netherlands)

    Kranenburg, Guido; Spiering, Wilko; de Jong, Pim A.; Kappelle, L. Jaap; de Borst, Gert Jan; Cramer, Maarten J.; Visseren, Frank L.J.; Aboyans, Victor; Westerink, Jan

    2017-01-01

    Background Inter-arm systolic blood pressure difference (SBPD) is an easily obtained patient characteristic which relates to vascular disease. We aimed to identify determinants of large inter-arm SBPD and to investigate the relation between inter-arm SBPD and vascular events in patients with and

  6. Deleterious effects of tributyltin on porcine vascular stem cells physiology.

    Science.gov (United States)

    Bernardini, Chiara; Zannoni, Augusta; Bertocchi, Martina; Bianchi, Francesca; Salaroli, Roberta; Botelho, Giuliana; Bacci, Maria Laura; Ventrella, Vittoria; Forni, Monica

    2016-01-01

    The vascular functional and structural integrity is essential for the maintenance of the whole organism and it has been demonstrated that different types of vascular progenitor cells resident in the vessel wall play an important role in this process. The purpose of the present research was to observe the effect of tributyltin (TBT), a risk factor for vascular disorders, on porcine Aortic Vascular Precursor Cells (pAVPCs) in term of cytotoxicity, gene expression profile, functionality and differentiation potential. We have demonstrated that pAVPCs morphology deeply changed following TBT treatment. After 48h a cytotoxic effect has been detected and Annexin binding assay demonstrated that TBT induced apoptosis. The transcriptional profile of characteristic pericyte markers has been altered: TBT 10nM substantially induced alpha-SMA, while, TBT 500nM determined a significant reduction of all pericyte markers. IL-6 protein detected in the medium of pAVPCs treated with TBT at both doses studied and with a dose response. TBT has interfered with normal pAVPC functionality preventing their ability to support a capillary-like network. In addition TBT has determined an increase of pAVPC adipogenic differentiation. In conclusion in the present paper we have demonstrated that TBT alters the vascular stem cells in terms of structure, functionality and differentiating capability, therefore effects of TBT in blood should be deeply explored to understand the potential vascular risk associated with the alteration of vascular stem cell physiology. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Is Pseudoexfoliation Syndrome a Risk Factor for Cerebro Vascular Disease?

    Science.gov (United States)

    Kan, Emrah; Yılmaz, Ahmet; Demirağ, Mehmet Derya; Çalık, Murat

    2017-01-01

    To determine the relationship between cerebro vascular disease and pseudoexfoliation syndrome. This cross-sectional case control study consisted of 50 patients with ischemic-type cerebro vascular disease and 50 control subjects. All subjects were investigated for diabetes mellitus and hypertension status and underwent a detailed ophthalmic examination. A diagnosis of pseudoexfoliation syndrome was made if characteristic greyish particulate matter was found on the anterior lens capsule after pupillary dilatation by slit-lamp examination. All subjects were compared in terms of pseudoexfoliation syndrome, diabetes mellitus, and hypertension. Pearson Chi Square and Student's t test were used for statistical analysis. Logistic regression analyses of the risk factors between groups were also made. The presence of pseudoexfoliation syndrome was significantly higher in patients with cerebro vascular disease when compared to the control subjects (p = 0.02). The frequency of diabetes mellitus was similar between the two groups. Arterial hypertension was significantly more frequent in the patient group when compared to the control subjects (p cerebro vascular disease. In the present study, we found that pseudoexfoliation syndrome frequency was found to be higher in patients with cerebro vascular disease than in control subjects. A slit-lamp examination of the eye could be an important marker that indicates the risk of cerebro vascular disease. We recommend an evaluation of all subjects with pseudoexfoliation syndrome for the presence of cerebro vascular disease. Longitudinal studies with larger populations are needed to confirm this relationship.

  8. Poland syndrome associated with an aberrant subclavian artery and vascular abnormalities of the retina in a child exposed to misoprostol during pregnancy.

    Science.gov (United States)

    Rosa, Rafael Fabiano Machado; Travi, Giovanni M; Valiatti, Fabiana; Zen, Paulo Ricardo Gazzola; Pinto, Louise Lapagesse; Kiss, Andrea; Graziadio, Carla; Paskulin, Giorgio Adriano

    2007-06-01

    Poland syndrome has been attributed to a process of vascular disruption, and exposure to misoprostol at 6-8 weeks of gestation has been shown to produce defects attributed to vascular disruption. Herein we report the first case of a patient with Poland syndrome associated with an aberrant subclavian artery and vascular abnormalities of the retina, whose mother used misoprostol during pregnancy. A White boy of 1 year and 7 months of age, whose mother used misoprostol during the second month of pregnancy, presented with bilateral epicanthal folds, aplasia of the sternocostal head of the pectoralis major muscle with a hypoplastic nipple on the right side, and asymmetry between the upper limbs. The results of an angiotomographic study showed the presence of an aberrant right subclavian artery. Ultrasonographic evaluation showed turbulence and a high peak in the diastolic velocity in both carotid arteries, suggesting stenosis. Ophthalmologic assessment disclosed an intense bilateral tortuosity of the retinal blood vessels, with arterialnarrowing and rarefaction of the retinal pigment epithelium. This case suggests that the mechanism of vascular disruption of misoprostol could be related to the aberrant subclavian artery and the observed Poland syndrome. His retinal findings are different from those in cases described thus far in the literature, and this pattern of anomaly has never been associated with a gestational exposure to misoprostol. The possibility of a relationship of the aberrant right subclavian artery and the pattern of blood flow verified in the carotid arteries with the eye fundus abnormalities could be causally related or simply coincidental.

  9. Cardiac and vascular malformations

    International Nuclear Information System (INIS)

    Ley, S.; Ley-Zaporozhan, J.

    2015-01-01

    Malformations of the heart and great vessels show a high degree of variation. There are numerous variants and defects with only few clinical manifestations and are only detected by chance, such as a persistent left superior vena cava or a partial anomalous pulmonary venous connection. Other cardiovascular malformations are manifested directly after birth and need prompt mostly surgical interventions. At this point in time echocardiography is the diagnostic modality of choice for morphological and functional characterization of malformations. Additional imaging using computed tomography (CT) or magnetic resonance imaging (MRI) is only required in a minority of cases. If so, the small anatomical structures, the physiological tachycardia and tachypnea are a challenge for imaging modalities and strategies. This review article presents the most frequent vascular, cardiac and complex cardiovascular malformations independent of the first line diagnostic imaging modality. (orig.) [de

  10. Biomaterial-mediated strategies targeting vascularization for bone repair.

    Science.gov (United States)

    García, José R; García, Andrés J

    2016-04-01

    Repair of non-healing bone defects through tissue engineering strategies remains a challenging feat in the clinic due to the aversive microenvironment surrounding the injured tissue. The vascular damage that occurs following a bone injury causes extreme ischemia and a loss of circulating cells that contribute to regeneration. Tissue-engineered constructs aimed at regenerating the injured bone suffer from complications based on the slow progression of endogenous vascular repair and often fail at bridging the bone defect. To that end, various strategies have been explored to increase blood vessel regeneration within defects to facilitate both tissue-engineered and natural repair processes. Developments that induce robust vascularization will need to consolidate various parameters including optimization of embedded therapeutics, scaffold characteristics, and successful integration between the construct and the biological tissue. This review provides an overview of current strategies as well as new developments in engineering biomaterials to induce reparation of a functional vascular supply in the context of bone repair.

  11. CIRSE Vascular Closure Device Registry

    NARCIS (Netherlands)

    Reekers, Jim A.; Müller-Hülsbeck, Stefan; Libicher, Martin; Atar, Eli; Trentmann, Jens; Goffette, Pierre; Borggrefe, Jan; Zeleňák, Kamil; Hooijboer, Pieter; Belli, Anna-Maria

    2011-01-01

    Vascular closure devices are routinely used after many vascular interventional radiology procedures. However, there have been no major multicenter studies to assess the safety and effectiveness of the routine use of closure devices in interventional radiology. The CIRSE registry of closure devices

  12. Dynamic adaption of vascular morphology

    DEFF Research Database (Denmark)

    Okkels, Fridolin; Jacobsen, Jens Christian Brings

    2012-01-01

    The structure of vascular networks adapts continuously to meet changes in demand of the surrounding tissue. Most of the known vascular adaptation mechanisms are based on local reactions to local stimuli such as pressure and flow, which in turn reflects influence from the surrounding tissue. Here ...

  13. Diagnostic criteria for vascular dementia

    NARCIS (Netherlands)

    Scheltens, P.; Hijdra, A. H.

    1998-01-01

    The term vascular dementia implies the presence of a clinical syndrome (dementia) caused by, or at least assumed to be caused by, a specific disorder (cerebrovascular disease). In this review, the various sets of criteria used to define vascular dementia are outlined. The various sets of criteria

  14. The vascular secret of Klotho

    DEFF Research Database (Denmark)

    Lewin, Ewa; Olgaard, Klaus

    2015-01-01

    Klotho is an evolutionarily highly conserved protein related to longevity. Increasing evidence of a vascular protecting effect of the Klotho protein has emerged and might be important for future treatments of uremic vascular calcification. It is still disputed whether Klotho is locally expressed ...

  15. Social media in vascular surgery.

    Science.gov (United States)

    Indes, Jeffrey E; Gates, Lindsay; Mitchell, Erica L; Muhs, Bart E

    2013-04-01

    There has been a tremendous growth in the use of social media to expand the visibility of various specialties in medicine. The purpose of this paper is to describe the latest updates on some current applications of social media in the practice of vascular surgery as well as existing limitations of use. This investigation demonstrates that the use of social networking sites appears to have a positive impact on vascular practice, as is evident through the incorporation of this technology at the Cleveland Clinic and by the Society for Vascular Surgery into their approach to patient care and physician communication. Overall, integration of social networking technology has current and future potential to be used to promote goals, patient awareness, recruitment for clinical trials, and professionalism within the specialty of vascular surgery. Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

  16. CLINICAL ANALYSIS OF SERUM INTERLEUKIN-16 AND VASCULAR ENDOTHELIAL GROWTH FACTOR LEVELS DEPENDING ON MORPHOLOGICAL CHARACTERISTICS OF THE TUMORS AND LONG-TERM TREATMENT OUTCOMES IN PATIENTS WITH BONE NEOPLASMS

    Directory of Open Access Journals (Sweden)

    I. V. Babkina

    2016-01-01

    Full Text Available Background: The progress in cancer treatment, including bone malignancies, is associated with advances in molecular biology. Based on the results of a  number of studies, treatment of bone sarcomas have been expanded with targeted therapy that uses drugs with targeted actions, including anti-angiogenic and bevacizumab, in particular. It inhibits the binding of a key activator of neoangiogenesis, vascular endothelial growth factor (VEGF, with its receptors type 1 and 2 (Flt-1 and KDR on the surface of endothelial cells, which results in a  decrease in vascularization and in inhibition of tumor growth. Beyond VEGF, other activators of neoangiogenesis have been identified, such as interleukin 16 (IL-16. Aim: To compare baseline serum IL-16 and VEGF in patients with malignant, borderline and benign bone tumors. Materials and methods: Serum IL-16 and VEGF levels was compared in 138 patients with primary bone tumors: benign (n=10; borderline (giant cell bone, n=22; malignant (n=106, aged 14 to 50 years, by immunoenzyme assay (Biosource, USA for IL-16 and R&D, USA for VEGF before any specific treatment. Bone malignancies were identified as osteosarcoma (n=45, among them 35  typical, 6 parosteal, and 4 periosteal, chondrosarcoma (n=24, Ewing sarcoma (n=27, and undifferentiated pleomorphic sarcoma (n=7 and chordoma (n=3. Results: The rate of IL-16 identification in the serum of bone tumors patients was 93%, with no significant differences depending on the histological structure of the tumor. No association between the size of primary tumors and IL-16 serum levels was found. Overall 3 and 5-year survival of patients with malignant bone tumors with IL-16 serum levels>33 pg/mL was significantly lower than in those IL-16 levels of≤33 pg/mL. Overall 5-year survival in osteosarcoma patients with higher IL-16 serum levels 1.6-fold lower, in Ewing sarcoma patients, 1.7-fold lower, and in chondrosarcoma patients, 1.8-fold lower than that the patients with

  17. Vascular disease in cocaine addiction.

    Science.gov (United States)

    Bachi, Keren; Mani, Venkatesh; Jeyachandran, Devi; Fayad, Zahi A; Goldstein, Rita Z; Alia-Klein, Nelly

    2017-07-01

    Cocaine, a powerful vasoconstrictor, induces immune responses including cytokine elevations. Chronic cocaine use is associated with functional brain impairments potentially mediated by vascular pathology. Although the Crack-Cocaine epidemic has declined, its vascular consequences are increasingly becoming evident among individuals with cocaine use disorder of that period, now aging. Paradoxically, during the period when prevention efforts could make a difference, this population receives psychosocial treatment at best. We review major postmortem and in vitro studies documenting cocaine-induced vascular toxicity. PubMed and Academic Search Complete were used with relevant terms. Findings consist of the major mechanisms of cocaine-induced vasoconstriction, endothelial dysfunction, and accelerated atherosclerosis, emphasizing acute, chronic, and secondary effects of cocaine. The etiology underlying cocaine's acute and chronic vascular effects is multifactorial, spanning hypertension, impaired homeostasis and platelet function, thrombosis, thromboembolism, and alterations in blood flow. Early detection of vascular disease in cocaine addiction by multimodality imaging is discussed. Treatment may be similar to indications in patients with traditional risk-factors, with few exceptions such as enhanced supportive care and use of benzodiazepines and phentolamine for sedation, and avoiding β-blockers. Given the vascular toxicity cocaine induces, further compounded by smoking and alcohol comorbidity, and interacting with aging of the crack generation, there is a public health imperative to identify pre-symptomatic markers of vascular impairments in cocaine addiction and employ preventive treatment to reduce silent disease progression. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. [The future of vascular medicine].

    Science.gov (United States)

    Kroeger, K; Luther, B

    2014-10-01

    In the future vascular medicine will still have a great impact on health of people. It should be noted that the aging of the population does not lead to a dramatic increase in patient numbers, but will be associated with a changing spectrum of co-morbidities. In addition, vascular medical research has to include the intensive care special features of vascular patients, the involvement of vascular medicine in a holistic concept of fast-track surgery, a geriatric-oriented intensive monitoring and early geriatric rehabilitation. For the future acceptance of vascular medicine as a separate subject area under delimitation of cardiology and radiology is important. On the other hand, the subject is so complex and will become more complex in future specialisations that mixing of surgery and angiology is desirable, with the aim to preserve the vascular surgical knowledge and skills on par with the medical and interventional measures and further develop them. Only large, interdisciplinary guided vascular centres will be able to provide timely diagnosis and therapy, to deal with the growing multi-morbidity of the patient, to perform complex therapies even in an acute emergency and due to sufficient number of cases to present with well-trained and experienced teams. These requirements are mandatory to decrease patients' mortality step by step. Georg Thieme Verlag KG Stuttgart · New York.

  19. Contemporary vascular smartphone medical applications.

    Science.gov (United States)

    Carter, Thomas; O'Neill, Stephen; Johns, Neil; Brady, Richard R W

    2013-08-01

    Use of smartphones and medical mHealth applications (apps) within the clinical environment provides a potential means for delivering elements of vascular care. This article reviews the contemporary availability of apps specifically themed to major vascular diseases and the opportunities and concerns regarding their integration into practice. Smartphone apps relating to major vascular diseases were identified from the app stores for the 6 most popular smartphone platforms, including iPhone, Android, Blackberry, Nokia, Windows, and Samsung. Search terms included peripheral artery (arterial) disease, varicose veins, aortic aneurysm, carotid artery disease, amputation, ulcers, hyperhydrosis, thoracic outlet syndrome, vascular malformation, and lymphatic disorders. Forty-nine vascular-themed apps were identified. Sixteen (33%) were free of charge. Fifteen apps (31%) had customer satisfaction ratings, but only 3 (6%) had greater than 100. Only 13 apps (27%) had documented medical professional involvement in their design or content. The integration of apps into the delivery of care has the potential to benefit vascular health care workers and patients. However, high-quality apps designed by clinicians with vascular expertise are currently lacking and represent an area of concern in the mHealth market. Improvement in the quality and reliability of these apps will require the development of robust regulation. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Constructal vascularized structures

    Science.gov (United States)

    Cetkin, Erdal

    2015-06-01

    Smart features such as self-healing and selfcooling require bathing the entire volume with a coolant or/and healing agent. Bathing the entire volume is an example of point to area (or volume) flows. Point to area flows cover all the distributing and collecting kinds of flows, i.e. inhaling and exhaling, mining, river deltas, energy distribution, distribution of products on the landscape and so on. The flow resistances of a point to area flow can be decreased by changing the design with the guidance of the constructal law, which is the law of the design evolution in time. In this paper, how the flow resistances (heat, fluid and stress) can be decreased by using the constructal law is shown with examples. First, the validity of two assumptions is surveyed: using temperature independent Hess-Murray rule and using constant diameter ducts where the duct discharges fluid along its edge. Then, point to area types of flows are explained by illustrating the results of two examples: fluid networks and heating an area. Last, how the structures should be vascularized for cooling and mechanical strength is documented. This paper shows that flow resistances can be decreased by morphing the shape freely without any restrictions or generic algorithms.

  1. The influence of perivascular adipose tissue on vascular homeostasis.

    Science.gov (United States)

    Szasz, Theodora; Bomfim, Gisele Facholi; Webb, R Clinton

    2013-01-01

    The perivascular adipose tissue (PVAT) is now recognized as an active contributor to vascular function. Adipocytes and stromal cells contained within PVAT are a source of an ever-growing list of molecules with varied paracrine effects on the underlying smooth muscle and endothelial cells, including adipokines, cytokines, reactive oxygen species, and gaseous compounds. Their secretion is regulated by systemic or local cues and modulates complex processes, including vascular contraction and relaxation, smooth muscle cell proliferation and migration, and vascular inflammation. Recent evidence demonstrates that metabolic and cardiovascular diseases alter the morphological and secretory characteristics of PVAT, with notable consequences. In obesity and diabetes, the expanded PVAT contributes to vascular insulin resistance. PVAT-derived cytokines may influence key steps of atherogenesis. The physiological anticontractile effect of PVAT is severely diminished in hypertension. Above all, a common denominator of the PVAT dysfunction in all these conditions is the immune cell infiltration, which triggers the subsequent inflammation, oxidative stress, and hypoxic processes to promote vascular dysfunction. In this review, we discuss the currently known mechanisms by which the PVAT influences blood vessel function. The important discoveries in the study of PVAT that have been made in recent years need to be further advanced, to identify the mechanisms of the anticontractile effects of PVAT, to explore the vascular-bed and species differences in PVAT function, to understand the regulation of PVAT secretion of mediators, and finally, to uncover ways to ameliorate cardiovascular disease by targeting therapeutic approaches to PVAT.

  2. Diabetes and Retinal Vascular Dysfunction

    Directory of Open Access Journals (Sweden)

    Eui Seok Shin

    2014-01-01

    Full Text Available Diabetes predominantly affects the microvascular circulation of the retina resulting in a range of structural changes unique to this tissue. These changes ultimately lead to altered permeability, hyperproliferation of endothelial cells and edema, and abnormal vascularization of the retina with resulting loss of vision. Enhanced production of inflammatory mediators and oxidative stress are primary insults with significant contribution to the pathogenesis of diabetic retinopathy (DR. We have determined the identity of the retinal vascular cells affected by hyperglycemia, and have delineated the cell autonomous impact of high glucose on function of these cells. We discuss some of the high glucose specific changes in retinal vascular cells and their contribution to retinal vascular dysfunction. This knowledge provides novel insight into the molecular and cellular defects contributing to the development and progression of diabetic retinopathy, and will aid in the development of innovative, as well as target specific therapeutic approaches for prevention and treatment of DR.

  3. Vascular graft infections with Mycoplasma

    DEFF Research Database (Denmark)

    Levi-Mazloum, Niels Donald; Skov Jensen, J; Prag, J

    1995-01-01

    laboratory techniques, the percentage of culture-negative yet grossly infected vascular grafts seems to be increasing and is not adequately explained by the prior use of antibiotics. We have recently reported the first case of aortic graft infection with Mycoplasma. We therefore suggest the hypothesis...... that the large number of culture-negative yet grossly infected vascular grafts may be due to Mycoplasma infection not detected with conventional laboratory technique....

  4. Limb vascular function in women

    DEFF Research Database (Denmark)

    Hellsten, Ylva; Gliemann, Lasse

    2018-01-01

    Throughout life, women are subjected to both acute fluctuations in sex hormones, associated with the menstrual cycle, and chronic changes following the onset of menopause. Female sex hormones, and in particular estrogen, strongly influence cardiovascular function such as the regulation of vascular...... studies. Physical activity should be recommended for women of all ages, but the most essential timing for maintenance of vascular health may be from menopause and onwards....

  5. Facial vascular malformations in children

    International Nuclear Information System (INIS)

    Brunelle, F.O.; Lallemand, D.; Chaumont, P.; Teillac, D.; Manach, Y.

    1988-01-01

    The authors present their experience with conventional and digital angiography of vascular malformations of the head and neck in children. 22 hemangioendotheliomas, 8 venous angiomas, and 3 arteriovenous fistula were studied. 22 patients were embolised. DSA offers many advantages during the diagnostic as well as during the therapeutic phase of angiography. Embolization appears to have a major role in treatment of such vascular malformations. (orig.)

  6. Angiogenesis, Cancer, and Vascular Aging

    Directory of Open Access Journals (Sweden)

    Junji Moriya

    2017-10-01

    Full Text Available Several lines of evidence have revealed that the angiogenic response to ischemic injury declines with age, which might account for the increased morbidity and mortality of cardiovascular disease (CVD among the elderly. While impairment of angiogenesis with aging leads to delayed wound healing or exacerbation of atherosclerotic ischemic diseases, it also inhibits the progression of cancer. Age-related changes of angiogenesis have been considered to at least partly result from vascular aging or endothelial cell senescence. There is considerable evidence supporting the hypothesis that vascular cell senescence contributes to the pathogenesis of age-related CVD, suggesting that vascular aging could be an important therapeutic target. Since therapeutic angiogenesis is now regarded as a promising concept for patients with ischemic CVD, it has become even more important to understand the detailed molecular mechanisms underlying impairment of angiogenesis in older patients. To improve the usefulness of therapeutic angiogenesis, approaches are needed that can compensate for impaired angiogenic capacity in the elderly while not promoting the development or progression of malignancy. In this review, we briefly outline the mechanisms of angiogenesis and vascular aging, followed by a description of how vascular aging leads to impairment of angiogenesis. We also examine potential therapeutic approaches that could enhance angiogenesis and/or vascular function in the elderly, as well as discussing the possibility of anti-senescence therapy or reversal of endothelial cell senescence.

  7. Maturation of the auditory system in clinically normal puppies as reflected by the brain stem auditory-evoked potential wave V latency-intensity curve and rarefaction-condensation differential potentials.

    Science.gov (United States)

    Poncelet, L C; Coppens, A G; Meuris, S I; Deltenre, P F

    2000-11-01

    To evaluate auditory maturation in puppies. Ten clinically normal Beagle puppies. Puppies were examined repeatedly from days 11 to 36 after birth (8 measurements). Click-evoked brain stem auditory-evoked potentials (BAEP) were obtained in response to rarefaction and condensation click stimuli from 90 dB normal hearing level to wave V threshold, using steps of 10 dB. Responses were added, providing an equivalent to alternate polarity clicks, and subtracted, providing the rarefaction-condensation differential potential (RCDP). Steps of 5 dB were used to determine thresholds of RCDP and wave V. Slope of the low-intensity segment of the wave V latency-intensity curve was calculated. The intensity range at which RCDP could not be recorded (ie, pre-RCDP range) was calculated by subtracting the threshold of wave V from threshold of RCDP RESULTS: Slope of the wave V latency-intensity curve low-intensity segment evolved with age, changing from (mean +/- SD) -90.8 +/- 41.6 to -27.8 +/- 4.1 micros/dB. Similar results were obtained from days 23 through 36. The pre-RCDP range diminished as puppies became older, decreasing from 40.0 +/- 7.5 to 20.5 +/- 6.4 dB. Changes in slope of the latency-intensity curve with age suggest enlargement of the audible range of frequencies toward high frequencies up to the third week after birth. Decrease in the pre-RCDP range may indicate an increase of the audible range of frequencies toward low frequencies. Age-related reference values will assist clinicians in detecting hearing loss in puppies.

  8. Calcium dynamics in vascular smooth muscle

    OpenAIRE

    Amberg, Gregory C.; Navedo, Manuel F.

    2013-01-01

    Smooth muscle cells are ultimately responsible for determining vascular luminal diameter and blood flow. Dynamic changes in intracellular calcium are a critical mechanism regulating vascular smooth muscle contractility. Processes influencing intracellular calcium are therefore important regulators of vascular function with physiological and pathophysiological consequences. In this review we discuss the major dynamic calcium signals identified and characterized in vascular smooth muscle cells....

  9. Injuries to the vascular endothelium: vascular wall and endothelial dysfunction.

    Science.gov (United States)

    Fisher, Mark

    2008-01-01

    Vascular endothelial injury has multiple elements, and this article focuses on ischemia-related processes that have particular relevance to ischemic stroke. Distinctions between necrotic and apoptotic cell death provide a basic science context in which to better understand the significance of classical core and penumbra concepts of acute stroke, with apoptotic processes particularly prominent in the penumbra. The mitochondria are understood to serve as a reservoir of proteins that mediate apoptosis. Oxidative stress pathways generating reactive oxygen species (ROS) are prominent in endothelial injury, both ischemic and nonischemic, with prominent roles of enzyme- and nonenzymemediated pathways; mitochondria once again have a critical role, particularly in the nonenzymatic pathways generating ROS. Inflammation also contributes to vascular endothelial injury, and endothelial cells have the capacity to rapidly increase expression of inflammatory mediators following ischemic challenge; this leads to enhanced leukocyte-endothelial interactions mediated by selectins and adhesion molecules. Preconditioning consists of a minor version of an injurious event, which in turn may protect vascular endothelium from injury following a more substantial event. Presence of the blood-brain barrier creates unique responses to endothelial injury, with permeability changes due to impairment of endothelial-matrix interactions compounding altered vasomotor tone and tissue perfusion mediated by nitric oxide. Pharmacological protection against vascular endothelial injury can be provided by several of the phosphodiesterases (cilostazol and dipyridamole), along with statins. Optimal clinical responses for protection of brain vascular endothelium may use preconditioning as a model, and will likely require combined protection against apoptosis, ROS, and inflammation.

  10. Non-invasive vascular imaging: assessing tumour vascularity

    International Nuclear Information System (INIS)

    Delorme, S.; Knopp, M.V.

    1998-01-01

    Non-invasive assessment of vascularity is a new diagnostic approach to characterise tumours. Vascular assessment is based on the pathophysiology of tumour angiogenesis and its diagnostic implications for tumour biology, prognosis and therapy response. Two current techniques investigating vascular features in addition to morphology are Doppler ultrasonography and contrast-enhanced MRI. Diagnostic differentiation has been shown to be possible with Doppler, and a high degree of observed vascularity could be linked to an aggressive course of the disease. Dynamic MRI using gadolinium chelates is already used clinically to detect and differentiate tumours. The histological correlation shows that capillary permeability is increased in malignant tumours and is the best criterion for differentiation from benign processes. Permeability and perfusion factors seem to be more diagnostic than overall vessel density. New clinical applications are currently being established for therapy monitoring. Further instrumental developments will bring harmonic imaging in Doppler, and faster imaging techniques, higher spatial resolution and novel pharmacokinetic concepts in MRI. Upcoming contrast agents for both Doppler and MRI will further improve estimation of intratumoural blood volume and vascular permeability. (orig.)

  11. Characteristic effects of heavy ion irradiation on the rat brain

    International Nuclear Information System (INIS)

    Sun, X.Z.; Takahashi, S.; Kubota, Y.; Yoshida, S.; Takeda, H.; Zhang, R.; Fukui, Y.

    2005-01-01

    successfully and satisfactorily retained its high-dose localization in the defined region. Histological and neuronal behavioral examinations showed that no obvious behavioral and histological changes before 7 weeks of exposure, but loss of hairs was found in the left brain this time in the irradiated group. The shape and size of depilation were almost same to the left collimation. At 8 weeks after exposure, the distinctive histological changes such as necrosis, vascular dilatation and tissue swelling were observed and almost animals exposed to the heavy ion beams exhibited behavioral changes, either in an abnormal walking pattern or rotation when suspended by their tail. From 16 to 32 weeks after irradiation, necrotic rarefaction became dominant at the center of the irradiated region and enlarged blood vessels were present in the surrounding area. Behavioral changes during this period also became more marked. The rats showed total loss of their balance both in an abnormal walking pattern and rotation from 16 weeks onwards, Major elemental contribution in the brain studied with X-rays fluorescence indicated that a sudden decrease in the concentration of K and Cl appeared as early as 24 hours after ischemia induction in the rat brain, while the concentrations of P, Fe and Zn did not significantly change. A decrease in the concentration of K and P in the region where tissue selling and necrosis was observed. Significant increases in the concentrations of Cl, Fe, Zn were found in the thalamus and surrounding area o f necrosis. These results revealed that levels of inorganic ions in the brain were good indicators for the pathological states of the nervous system.

  12. Pediatric interventional radiology: vascular interventions

    International Nuclear Information System (INIS)

    Kandasamy, Devasenathipathy; Gamanagatti, Shivanand; Gupta, Arun Kumar

    2016-01-01

    Pediatric interventional radiology (PIR) comprises a range of minimally invasive diagnostic and therapeutic procedures that are performed using image guidance. PIR has emerged as an essential adjunct to various surgical and medical conditions. Over the years, technology has undergone dramatic and continuous evolution, making this speciality grow. In this review, the authors will discuss various vascular interventional procedures undertaken in pediatric patients. It is challenging for the interventional radiologist to accomplish a successful interventional procedure. There are many vascular interventional radiology procedures which are being performed and have changed the way the diseases are managed. Some of the procedures are life saving and have become the treatment of choice in those patients. The future is indeed bright for the practice and practitioners of pediatric vascular and non-vascular interventions. As more and more of the procedures that are currently being performed in adults get gradually adapted for use in the pediatric population, it may be possible to perform safe and successful interventions in many of the pediatric vascular lesions that are otherwise being referred for surgery. (author)

  13. Fetal origin of vascular aging

    Directory of Open Access Journals (Sweden)

    Shailesh Pitale

    2011-01-01

    Full Text Available Aging is increasingly regarded as an independent risk factor for development of cardiovascular diseases such as atherosclerosis and hypertension and their complications (e.g. MI and Stroke. It is well known that vascular disease evolve over decades with progressive accumulation of cellular and extracellular materials and many inflammatory processes. Metabolic syndrome, obesity and diabetes are conventionally recognized as risk factors for development of coronary vascular disease (CVD. These conditions are known to accelerate ageing process in general and vascular ageing in particular. Adverse events during intrauterine life may programme organ growth and favour disease later in life, popularly known as, ′Barker′s Hypothesis′. The notion of fetal programming implies that during critical periods of prenatal growth, changes in the hormonal and nutritional milieu of the conceptus may alter the full expression of the fetal genome, leading to permanent effects on a range of physiological.

  14. Imaging after vascular gene therapy

    International Nuclear Information System (INIS)

    Manninen, Hannu I.; Yang, Xiaoming

    2005-01-01

    Targets for cardiovascular gene therapy currently include limiting restenosis after balloon angioplasty and stent placement, inhibiting vein bypass graft intimal hyperplasia/stenosis, therapeutic angiogenesis for cardiac and lower-limb ischemia, and prevention of thrombus formation. While catheter angiography is still standard method to follow-up vascular gene transfer, other modern imaging techniques, especially intravascular ultrasound (IVUS), magnetic resonance (MR), and positron emission tomography (PET) imaging provide complementary information about the therapeutic effect of vascular gene transfer in humans. Although molecular imaging of therapeutic gene expression in the vasculatures is still in its technical development phase, it has already offered basic medical science an extremely useful in vivo evaluation tool for non- or minimally invasive imaging of vascular gene therapy

  15. The influence of perivascular adipose tissue on vascular homeostasis

    Directory of Open Access Journals (Sweden)

    Szasz T

    2013-03-01

    Full Text Available Theodora Szasz,1 Gisele Facholi Bomfim,2 R Clinton Webb1 1Department of Physiology, Georgia Regents University, Augusta, USA; 2Department of Pharmacology, University of São Paulo, São Paulo, Brazil Abstract: The perivascular adipose tissue (PVAT is now recognized as an active contributor to vascular function. Adipocytes and stromal cells contained within PVAT are a source of an ever-growing list of molecules with varied paracrine effects on the underlying smooth muscle and endothelial cells, including adipokines, cytokines, reactive oxygen species, and gaseous compounds. Their secretion is regulated by systemic or local cues and modulates complex processes, including vascular contraction and relaxation, smooth muscle cell proliferation and migration, and vascular inflammation. Recent evidence demonstrates that metabolic and cardiovascular diseases alter the morphological and secretory characteristics of PVAT, with notable consequences. In obesity and diabetes, the expanded PVAT contributes to vascular insulin resistance. PVAT-derived cytokines may influence key steps of atherogenesis. The physiological anticontractile effect of PVAT is severely diminished in hypertension. Above all, a common denominator of the PVAT dysfunction in all these conditions is the immune cell infiltration, which triggers the subsequent inflammation, oxidative stress, and hypoxic processes to promote vascular dysfunction. In this review, we discuss the currently known mechanisms by which the PVAT influences blood vessel function. The important discoveries in the study of PVAT that have been made in recent years need to be further advanced, to identify the mechanisms of the anticontractile effects of PVAT, to explore the vascular-bed and species differences in PVAT function, to understand the regulation of PVAT secretion of mediators, and finally, to uncover ways to ameliorate cardiovascular disease by targeting therapeutic approaches to PVAT. Keywords: adipokines

  16. Hematological and vascular disorders

    International Nuclear Information System (INIS)

    Rowe, L.J.; Yochum, T.R.

    1987-01-01

    Numerous blood-related disorders will demonstrate skeletal alterations. These include various anemias, leukemias, lymphomas, and clotting-deficient diseases (hemophilia). Of all the various types of anemias only those that are chronic and severe will result in radiographically visible osseous changes. The skeletal alterations which are observed are invariably related to the direct effects on the bone marrow or are secondary to the inherent complications of the disease. The most notable osseous changes are seen in the congenital hemolytic anemias, especially thalassemia (Cooley's anemia), sickle cell anemia, and hereditary spherocytosis. Chronic iron deficiency anemia produces very minor skeletal changes, usually isolated to the skull. Leukemia demonstrates characteristic changes largely dependent on age. Hemophilia primarily alters joint function due to recurrent intraarticular hemorrhage. This chapter discusses blood-related disorders that affect the bones

  17. Vascular plant diversity and community Structure of nandi forests ...

    African Journals Online (AJOL)

    Abundance data of species was used for species diversity, similarity, species richness estimation and plant community analysis. PC-ORD, CANOCO and EstimateS were used to analyze the data. A total of 321 species ... Keywords: floristic composition, ordination, rarefaction, species accumulation, species richness.

  18. Vascular Gene Expression: A Hypothesis

    Directory of Open Access Journals (Sweden)

    Angélica Concepción eMartínez-Navarro

    2013-07-01

    Full Text Available The phloem is the conduit through which photoassimilates are distributed from autotrophic to heterotrophic tissues and is involved in the distribution of signaling molecules that coordinate plant growth and responses to the environment. Phloem function depends on the coordinate expression of a large array of genes. We have previously identified conserved motifs in upstream regions of the Arabidopsis genes, encoding the homologs of pumpkin phloem sap mRNAs, displaying expression in vascular tissues. This tissue-specific expression in Arabidopsis is predicted by the overrepresentation of GA/CT-rich motifs in gene promoters. In this work we have searched for common motifs in upstream regions of the homologous genes from plants considered to possess a primitive vascular tissue (a lycophyte, as well as from others that lack a true vascular tissue (a bryophyte, and finally from chlorophytes. Both lycophyte and bryophyte display motifs similar to those found in Arabidopsis with a significantly low E-value, while the chlorophytes showed either a different conserved motif or no conserved motif at all. These results suggest that these same genes are expressed coordinately in non- vascular plants; this coordinate expression may have been one of the prerequisites for the development of conducting tissues in plants. We have also analyzed the phylogeny of conserved proteins that may be involved in phloem function and development. The presence of CmPP16, APL, FT and YDA in chlorophytes suggests the recruitment of ancient regulatory networks for the development of the vascular tissue during evolution while OPS is a novel protein specific to vascular plants.

  19. [Vascular Calcification - Pathological Mechanism and Clinical Application - . Role of vascular smooth muscle cells in vascular calcification].

    Science.gov (United States)

    Kurabayashi, Masahiko

    2015-05-01

    Vascular calcification is commonly seen with aging, chronic kidney disese (CKD), diabetes, and atherosclerosis, and is closely associated with cardiovascular morbidity and mortality. Vascular calcification has long been regarded as the final stage of degeneration and necrosis of arterial wall and a passive, unregulated process. However, it is now known to be an active and tightly regulated process involved with phenotypic transition of vascular smooth muscle cells (VSMC) that resembles bone mineralization. Briefly, calcium deposits of atherosclerotic plaque consist of hydroxyapatite and may appear identical to fully formed lamellar bone. By using a genetic fate mapping strategy, VSMC of the vascular media give rise to the majority of the osteochondrogenic precursor- and chondrocyte-like cells observed in the calcified arterial media of MGP (- / -) mice. Osteogenic differentiation of VSMC is characterized by the expression of bone-related molecules including bone morphogenetic protein (BMP) -2, Msx2 and osteopontin, which are produced by osteoblasts and chondrocytes. Our recent findings are that (i) Runx2 and Notch1 induce osteogenic differentiation, and (ii) advanced glycation end-product (AGE) /receptor for AGE (RAGE) and palmitic acid promote osteogenic differentiation of VSMC. To understand of the molecular mechanisms of vascular calcification is now under intensive research area.

  20. Vascular malforma- tions part 1 — normal and abnormal vascular ...

    African Journals Online (AJOL)

    Enrique

    to form the primitive vascular plexus. Angiogenesis is the formation of new vessels by sprouting or splitting of ... The differentiation of primitive vessels into arteries, veins or capillaries is determined by flow patterns .... identify, but it is probable that as time progresses further specific genetic defects related to the development ...

  1. Genetic Regulation of Vascular Development: Building the Zebrafish Vascular Tree

    NARCIS (Netherlands)

    R.L.J.M. Herpers (Robert)

    2010-01-01

    textabstractThe extensive networks of blood and lymphatic vessels within the vertebrate body are essential for the transport and delivery of fluids, gases, macromolecules and cells, and play important roles in facilitating immune responses. The development of the vascular tree requires a highly

  2. Imaging findings and therapeutic alternatives for peripheral vascular malformations

    International Nuclear Information System (INIS)

    Monsignore, Lucas Moretti; Nakiri, Guilherme Seizem; Santos, Daniela dos; Abud, Thiago Giansante; Abud, Daniel Giansante

    2010-01-01

    Peripheral vascular malformations represent a spectrum of lesions that appear through the lifetime and can be found in the whole body. Such lesions are uncommon and are frequently confounded with infantile hemangioma, a common benign neoplastic lesion. In the presence of such lesions, the correlation between the clinical and radiological findings is extremely important to achieve a correct diagnosis, which will guide the best therapeutic approach. The most recent classifications for peripheral vascular malformations are based on the blood flow (low or high) and on the main vascular components (arterial, capillary, lymphatic or venous). Peripheral vascular malformations represent a diagnostic and therapeutic challenge, and complementary methods such as computed tomography, Doppler ultrasonography and magnetic resonance imaging, in association with clinical findings can provide information regarding blood flow characteristics and lesions extent. Arteriography and venography confirm the diagnosis, evaluate the lesions extent and guide the therapeutic decision making. Generally, low flow vascular malformations are percutaneously treated with sclerosing agents injection, while in high flow lesions the approach is endovascular, with permanent liquid or solid embolization agents. (author)

  3. [Vascular access guidelines for hemodialysis].

    Science.gov (United States)

    Rodríguez Hernández, J A; González Parra, E; Julián Gutiérrez, J M; Segarra Medrano, A; Almirante, B; Martínez, M T; Arrieta, J; Fernández Rivera, C; Galera, A; Gallego Beuter, J; Górriz, J L; Herrero, J A; López Menchero, R; Ochando, A; Pérez Bañasco, V; Polo, J R; Pueyo, J; Ruiz, Camps I; Segura Iglesias, R

    2005-01-01

    Quality of vascular access (VA) has a remarkable influence in hemodialysis patients outcomes. Dysfunction of VA represents a capital cause of morbi-mortality of these patients as well an increase in economical. Spanish Society of Neprhology, aware of the problem, has decided to carry out a revision of the issue with the aim of providing help in comprehensión and treatment related with VA problems, and achieving an homogenization of practices in three mayor aspects: to increase arteriovenous fistula utilization as first vascular access, to increment vascular access monitoring practice and rationalise central catheters use. We present a consensus document elaborated by a multidisciplinar group composed by nephrologists, vascular surgeons, interventional radiologysts, infectious diseases specialists and nephrological nurses. Along six chapters that cover patient education, creation of VA, care, monitoring, complications and central catheters, we present the state of the art and propose guidelines for the best practice, according different evidence based degrees, with the intention to provide help at the professionals in order to make aproppiate decissions. Several quality standars are also included.

  4. Image Quality in Vascular Radiology

    International Nuclear Information System (INIS)

    Vanhavere, F.; Struelens, L.

    2005-01-01

    In vascular radiology, the radiologists use the radiological image to diagnose or treat a specific vascular structure. From literature, we know that related doses are high and that large dose variability exists between different hospitals. The application of the optimization principle is therefore necessary and is obliged by the new legislation. So far, very little fieldwork has been performed and no practical instructions are available to do the necessary work. It's indisputable that obtaining quantitative data is of great interest for optimization purposes. In order to gain insight into these doses and the possible measures for dose reduction, we performed a comparative study in 7 hospitals. Patient doses will be measured and calculated for specific procedures in vascular radiology and evaluated against their most influencing parameters. In view of optimization purposes, a protocol for dose audit will be set-up. From the results and conclusions in this study, experimentally based guidelines will be proposed, in order to improve clinical practice in vascular radiology

  5. Vascular aspects of multiple sclerosis

    NARCIS (Netherlands)

    D'haeseleer, Miguel; Cambron, Melissa; Vanopdenbosch, Ludo; De Keyser, Jacques

    Three types of vascular dysfunction have been described in multiple sclerosis (MS). First, findings from epidemiological studies suggest that patients with MS have a higher risk for ischaemic stroke than people who do not have MS. The underlying mechanism is unknown, but might involve endothelial

  6. Characterization of midrib vascular bundles of selected medicinal species in Rubiaceae

    Science.gov (United States)

    Nurul-Syahirah, M.; Noraini, T.; Latiff, A.

    2016-11-01

    An anatomical study was carried out on mature leaves of five selected medicinal species of Rubiaceae from Peninsular Malaysia. The chosen medicinal species were Aidia densiflora, Aidia racemosa, Chasallia chartacea, Hedyotis auricularia and Ixora grandifolia. The objective of this study is to determine the taxonomic value of midrib anatomical characteristics. Leaves samples were collected from Taman Paku Pakis, Universiti Kebangsaan Malaysia, Bangi, Selangor and Kledang Saiong Forest Reserve, Perak, Malaysia. Leaves samples then were fixed in spirit and acetic acid (3:1), the midrib parts then were sectioned using sliding microtome, cleared using Clorox, stained in Safranin and Alcian blue, mounted in Euparal and were observed under light microscope. Findings in this study have shown all species have collateral bundles. The midrib vascular bundles characteristics that can be used as tool to differentiate between species or genus are vascular bundles system (opened or closed), shape and arrangement of main vascular bundles, presence of both additional and medullary vascular bundles, position of additional vascular bundles, shape of medullary vascular bundles, presence of sclerenchyma cells ensheathed the vascular bundles. As a conclusion, midrib anatomical characteristics can be used to identify and discriminate medicinal plants species studied in the Rubiaceae.

  7. Subclinical hypothyroidism after vascular complicated pregnancy

    NARCIS (Netherlands)

    Zanden, M. van der; Hop-de Groot, R.J.; Sweep, F.C.; Ross, H.A.; Heijer, M. den; Spaanderman, M.E.A.

    2013-01-01

    OBJECTIVE: Women with a history of vascular complicated pregnancy are at risk for developing remote cardiovascular disease. It is associated with underlying cardiovascular risk factors both jeopardizing trophoblast and vascular function. Subclinical hypothyroidism may relate to both conditions.

  8. Pediatric central nervous system vascular malformations

    International Nuclear Information System (INIS)

    Burch, Ezra A.; Orbach, Darren B.

    2015-01-01

    Pediatric central nervous system (CNS) vascular anomalies include lesions found only in the pediatric population and also the full gamut of vascular lesions found in adults. Pediatric-specific lesions discussed here include infantile hemangioma, vein of Galen malformation and dural sinus malformation. Some CNS vascular lesions that occur in adults, such as arteriovenous malformation, have somewhat distinct manifestations in children, and those are also discussed. Additionally, children with CNS vascular malformations often have associated broader vascular conditions, e.g., PHACES (posterior fossa anomalies, hemangioma, arterial anomalies, cardiac anomalies, eye anomalies and sternal anomalies), hereditary hemorrhagic telangiectasia, and capillary malformation-arteriovenous malformation syndrome (related to the RASA1 mutation). The treatment of pediatric CNS vascular malformations has greatly benefited from advances in endovascular therapy, including technical advances in adult interventional neuroradiology. Dramatic advances in therapy are expected to stem from increased understanding of the genetics and vascular biology that underlie pediatric CNS vascular malformations. (orig.)

  9. Pediatric central nervous system vascular malformations

    Energy Technology Data Exchange (ETDEWEB)

    Burch, Ezra A. [Brigham and Women' s Hospital, Department of Radiology, Boston, MA (United States); Orbach, Darren B. [Boston Children' s Hospital, Neurointerventional Radiology, Boston, MA (United States)

    2015-09-15

    Pediatric central nervous system (CNS) vascular anomalies include lesions found only in the pediatric population and also the full gamut of vascular lesions found in adults. Pediatric-specific lesions discussed here include infantile hemangioma, vein of Galen malformation and dural sinus malformation. Some CNS vascular lesions that occur in adults, such as arteriovenous malformation, have somewhat distinct manifestations in children, and those are also discussed. Additionally, children with CNS vascular malformations often have associated broader vascular conditions, e.g., PHACES (posterior fossa anomalies, hemangioma, arterial anomalies, cardiac anomalies, eye anomalies and sternal anomalies), hereditary hemorrhagic telangiectasia, and capillary malformation-arteriovenous malformation syndrome (related to the RASA1 mutation). The treatment of pediatric CNS vascular malformations has greatly benefited from advances in endovascular therapy, including technical advances in adult interventional neuroradiology. Dramatic advances in therapy are expected to stem from increased understanding of the genetics and vascular biology that underlie pediatric CNS vascular malformations. (orig.)

  10. ESRD QIP - Vascular Access - Payment Year 2018

    Data.gov (United States)

    U.S. Department of Health & Human Services — This dataset includes facility details, performance rates, vascular access topic measure score, and the state and national average measure scores for the vascular...

  11. Vascular neurocognitive disorders and the vascular risk factors

    Directory of Open Access Journals (Sweden)

    Carmen V. Albu

    2018-04-01

    Full Text Available Dementias are clinical neurodegenerative diseases characterized by permanent and progressive transformation of cognitive functions such as memory, learning capacity, attention, thinking, language, passing judgments, calculation or orientation. Dementias represent a relatively frequent pathology, encountered at about 10% of the population of 65-year olds and 20% of the population of 80-year olds. This review presents the main etiological forms of dementia, which include Alzheimer form of dementia, vascular dementia, dementia associated with alpha-synucleionopathies, and mixed forms. Regarding vascular dementia, the risk factors are similar to those for an ischemic or hemorrhagic cerebrovascular accident: arterial hypertension, diabetes mellitus, dyslipidemia, smoking, obesity, age, alcohol consumption, cerebral atherosclerosis/ arteriosclerosis. Several studies show that efficient management of the vascular risk factors can prevent the expression and/ or progression of dementia. Thus, lifestyle changes such as stress reduction, regular physical exercise, decreasing dietary fat, multivitamin supplementation, adequate control of blood pressure and serum cholesterol, and social integration and mental stimulation in the elderly population are important factors in preventing or limiting the symptoms of dementia, a disease with significant individual, social, and economic implications.

  12. Diversity of vascular plants of Piestany and surroundings (presentation)

    International Nuclear Information System (INIS)

    Penzesova, A.; Galusova, T.

    2013-01-01

    In this presentation is a summary of the results of floristic research aimed at determining diversity of vascular plants of Piestany and its surroundings. Plant taxa we determined using the designation keys. We have compiled a list of plant species occurring in the monitored area, we evaluated the selected botanical-phytogeographical characteristics of flora, we've put together a list of local protected, endangered and rare species and a list of local invasive and expansive species according to sources. (Authors)

  13. Skeletal Myocyte Types and Vascularity in the Black Sicilian Pig

    OpenAIRE

    S. Velotto; E. Varricchio; M. R. Di Prisco; T. Stasi; A. Crasto

    2007-01-01

    The objective of this study was to verify the presence of giant fibres in the Black Sicilian pig skeletal muscle and to evaluate the effect of sex on histochemical and morphometric characteristics of the myocytes (myofibres) as well as vascularity of the muscle. Twenty Black Sicilian pigs (10 males, 10 females) from a farm in Sicily (Italy) were slaughtered at two years of age. Muscle tissues were obtained from three muscles: psoas major, longissimus dorsi, and trapezius. Myofibres were stain...

  14. Vascularized osseous graft for scaphoid

    International Nuclear Information System (INIS)

    Mendez Daza, Carlos Hernan; Mathoulin, Cristophe

    2004-01-01

    The most commonly used technique for treatment of pseudo-arthrosis of the scaphoid is osteo-synthesis with Kirschnet wires and cortical sponge grafts. Results reported by different teams using this procedure show no more than 90% osseous consolidation, especially in cases where vascularisation of the proximal fragment of the scaphoid is compromised. Here we present a series of ten cases of pseudo-arthrosis of the scaphoid, treated using a new surgical technique involving a vascularized osseous graft of the distal radius. Using this procedure we obtained 100% consolidation, with no complications either during the procedure or immediately post-operatively. Patients returned to work in week 15 on average. In 4 cases we observed discomfort in the area of the scar, which was successfully treated using local cortisone injection. The results obtained are very similar to those seen in the literature on the different techniques for vascularized osseous grafts for pseudo-arthrosis of the scaphoid

  15. [Menopause: Hypertension and vascular disease].

    Science.gov (United States)

    Zilberman, J M

    Hypertension is the main cardiovascular risk factor affecting 25% of women. Hormone changes and hypertension after menopause may lead to higher target organ damage and cardiovascular disease such as increased arterial stiffness, coronary diseases, chronic heart failure and stroke. The physiopathological mechanisms involved in the development of hypertension and cardiovascular diseases in menopausal women are controversial. There are pharmacokinetic and pharmacodynamic differences in both sexes, the women have more coughing when using the converting-enzyme inhibitors, more cramps when using thiazide diuretics and more oedema in the inferior limbs when using calcium antagonists. The aim of this review is to analyse possible physiopathological mechanisms involved in hypertension after menopause and to gain a better understanding of the biological effects mediated by vascular ageing in women when the level of oestrogen protective effect decreases over the vascular system. Copyright © 2017 SEH-LELHA. Publicado por Elsevier España, S.L.U. All rights reserved.

  16. Vascular diagnostics for Raynaud's phenomenon

    Directory of Open Access Journals (Sweden)

    Dinsdale G

    2014-10-01

    Full Text Available Graham Dinsdale, Ariane L Herrick Centre for Musculoskeletal Research, Institute of Inflammation and Repair, Salford Royal NHS Foundation Trust, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK Abstract: Raynaud's phenomenon (RP is common, and in most patients is primary (idiopathic when due to reversible vasospasm and does not progress to irreversible tissue injury. However, in those patients for whom RP is secondary to an underlying disease (eg, systemic sclerosis or atherosclerosis, progression to digital ulceration or critical ischemia can occur. Therefore, the key question for the clinician is “Why does this patient have RP?” Vascular diagnostics play a key role in answering this. In this review, we firstly discuss the different vascular investigations relevant to clinical practice: nail fold capillaroscopy (including the different methodologies for examining the nail fold capillaries, and the role of capillaroscopy in helping to differentiate between primary and systemic sclerosis-related RP, thermography (available in specialist centers, and evaluation of large vessel disease (for example, due to atherosclerosis. We then discuss research tools, mainly laser Doppler methods, including laser Doppler imaging and laser speckle contrast imaging. These are commercially available as complete imaging systems and are (relatively easy to use. The main current goal in vascular imaging research is to validate these novel state-of-the-art techniques as outcome measures of digital vascular disease, and then apply them in early and later phase studies of new treatment approaches, thus facilitating drug development programs. Keywords: Raynaud's phenomenon, systemic sclerosis, nail fold capillaroscopy, thermography, laser Doppler, angiography

  17. Low vascularity predicts favourable outcomes in leiomyoma patients treated with uterine artery embolization.

    Science.gov (United States)

    Tang, Yixin; Chen, Chunlin; Duan, Hui; Ma, Ben; Liu, Ping

    2016-10-01

    To investigate the clinical factors predicting outcomes of leiomyoma treated with uterine artery embolization (UAE). A total of 183 uterine leiomyoma patients undergoing UAE were retrospectively analyzed. Patient age, characteristics of vascular supply in magnetic resonance imaging (MRI)/digital subtraction angiography (DSA), number, size and location of leiomyoma were recorded. Leiomyoma regrowth, new leiomyoma appearance and recurrence of any previously reported symptoms were carefully monitored over a mean follow-up of 30 months (median 32 months, range 12-80). Potential recurrence risk factors were analyzed by univariate and multivariate cox regression analysis. Twenty-three recurrences were recorded. The difference in the vascularity classification systems between MRI and DSA was not statistically significant (P = 0.059). High vascularity in MRI, high vascularity in DSA and multiple leiomyoma showed a significant risk of recurrence using univariate and multivariate analysis (P = 0.004, P leiomyoma recurrence (P > 0.05). Low vascularity and solitary leiomyoma indicated favourable outcomes in patients treated with UAE. • Low vascularity and solitary mass predicted favourable outcomes in UAE-treated patients. • MRI might provide information on vascularity in leiomyoma before UAE. • Variations in vascular supply, age, size, location were not associated with recurrence.

  18. The skeletal vascular system - Breathing life into bone tissue.

    Science.gov (United States)

    Stegen, Steve; Carmeliet, Geert

    2017-08-26

    During bone development, homeostasis and repair, a dense vascular system provides oxygen and nutrients to highly anabolic skeletal cells. Characteristic for the vascular system in bone is the serial organization of two capillary systems, each typified by specific morphological and physiological features. Especially the arterial capillaries mediate the growth of the bone vascular system, serve as a niche for skeletal and hematopoietic progenitors and couple angiogenesis to osteogenesis. Endothelial cells and osteoprogenitor cells interact not only physically, but also communicate to each other by secretion of growth factors. A vital angiogenic growth factor is vascular endothelial growth factor and its expression in skeletal cells is controlled by osteogenic transcription factors and hypoxia signaling, whereas the secretion of angiocrine factors by endothelial cells is regulated by Notch signaling, blood flow and possibly hypoxia. Bone loss and impaired fracture repair are often associated with reduced and disorganized blood vessel network and therapeutic targeting of the angiogenic response may contribute to enhanced bone regeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Algoflora and vascular flora of a limestone spring in the Warta river valley

    Directory of Open Access Journals (Sweden)

    Joanna Żelazna-Wieczorek

    2011-01-01

    Full Text Available Qualitative analysis of algae, including microhabitats and vascular vegetation in a spring niche, together with basic physical and chemical characteristics is presented. 175 diatom taxa as well as taxa of macroalgae and vascular plants were determined in the spring niche, and the community types were defined. Seasonal variability of diatom communities was observed. The influence of a flood as a catastrophe on the community of diatoms and macroalgae was noticed.

  20. [Fistulae or catheter for elderly who start hemodialysis without permanent vascular access?].

    Science.gov (United States)

    García Cortés, Ma J; Viedma, G; Sánchez Perales, M C; Borrego, F J; Borrego, J; Pérez del Barrio, P; Gil Cunquero, J M; Liébana, A; Pérez Bañasco, V

    2005-01-01

    Autologous access is the best vascular access for dialysis also in older patients and it should be mature when patient needs hemodialysis. It is not always possible. Surgeon availability and demographic characteristics of patients (age, diabetes, vascular disease...) are factors that determine primary vascular access. To analyse outcome and vascular access complications in elderly who start hemodialysis without vascular access. All patients older than 75 years who initiated hemodialysis without vascular access between January 2000 and June 2002 were included, They were divided en two groups depending on primary vascular access. GI: arterio-venous fistulae. GIIl: Tunnelled cuffed catheter. Epidemiological and analytical data, vascular access complications related, as well as patient and first permanent vascular access survival from their inclusion in dialysis up to December 2002 were analysed and compared in both groups. 32 patients were studied. GI: n = 17 (4 men) and GIIl: n =1 5 (8 men), age: 79.9 +/- 3.8 and 81.7 +/- 4 years respectively (ns). There were no differences in sex and comorbidity (diabetes, ischemic heart disease, peripheral vascular disease and hypertension). It took GI 3 months to get a permanent vascular access suitable for using, while it took GIIl 1.3 months (p catheters was higher in GI (3.35 vs 1.87 p central venous thrombosis happen in GI (I: 25 CVT/100 patients-year) vs 30% in GIIl (I = 14.4/100 patients-year) (ns). No significant differences neither in bleeding (66.7% vs 33.3%) nor ischemia (75% vs 25%) were found. Dialysis dose (Kt/V) as well as anaemia degree were similar in both groups. Permanent vascular access survival after 2 years was 45.8% in GI and 24% in GII (ns). Patient survival was similar in GI and GII (72% vs 51% ns). Elderly who start hemodialysis without vascular access took longer to get a suitable permanent vascular access when arterio-venous fistulae is placed than with a tunnelled cuffed hemodialysis catheter. As a

  1. Inter-arm systolic blood pressure differences, relations with future vascular events and mortality in patients with and without manifest vascular disease.

    Science.gov (United States)

    Kranenburg, Guido; Spiering, Wilko; de Jong, Pim A; Kappelle, L Jaap; de Borst, Gert Jan; Cramer, Maarten J; Visseren, Frank L J; Aboyans, Victor; Westerink, Jan

    2017-10-01

    Inter-arm systolic blood pressure difference (SBPD) is an easily obtained patient characteristic which relates to vascular disease. We aimed to identify determinants of large inter-arm SBPD and to investigate the relation between inter-arm SBPD and vascular events in patients with and without manifest vascular disease. In a cohort of 7344 patients with manifest vascular disease or vascular risk factors alone enrolled in the Second Manifestations of ARTerial disease (SMART) study, single bilateral non-simultaneous blood pressure measurements were performed. Logistic and Cox regression was used to identify determinants of large inter-arm SBPD (≥15mmHg) and to investigate the relation between inter-arm SBPD and vascular events (composite of non-fatal myocardial infarction, stroke, and vascular mortality) and all-cause mortality. In all patients the median inter-arm SBPD was 7mmHg (IQR 3-11) and 1182 (16%) patients had inter-arm SBPD ≥15mmHg. Higher age, higher systolic blood pressure, diabetes mellitus, peripheral artery disease, carotid artery stenosis, higher carotid intima-media thickness, and lower ankle-brachial indices were related to large inter-arm SBPD (≥15mmHg). Each 5mmHg increase in inter-arm SBPD was related to a 12% higher risk of vascular events in patients without manifest vascular disease (HR 1.12; 95% CI 1.00-1.27), whereas no relation was apparent in patients with manifest vascular disease (HR 0.98; 95% CI 0.93-1.04, interaction p-value 0.036). Inter-arm SBPD was not related to all-cause mortality (HR 1.05; 95% CI 0.93-1.19). Inter-arm SBPD relates to a higher risk of vascular events in patients without manifest vascular disease, whereas this relation is not apparent in patients with manifest vascular disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Ghrelin improves vascular autophagy in rats with vascular calcification.

    Science.gov (United States)

    Xu, Mingming; Liu, Lin; Song, Chenfang; Chen, Wei; Gui, Shuyan

    2017-06-15

    This study aimed to investigate whether ghrelin ameliorated vascular calcification (VC) through improving autophagy. VC model was induced by nicotine plus vitamin D 3 in rats and β-glycerophosphate in vascular smooth muscle cell (VSMC). Calcium deposition was detected by von Kossa staining or alizarin red S staining. ALP activity was also detected. Western blot was used to assess the protein expression. Ghrelin treatment attenuated the elevation of calcium deposition and ALP activity in VC model both in vivo and in vitro. Interesting, the protein levels of autophagy markers, LC3 and beclin1 were significantly upregulated by ghrelin in VC model. An autophagy inhibitor, 3-methyladenine blocks the ameliorative effect of ghrelin on VC. Furthermore, protein expressions of phosphate-AMPK were increased by ghrelin treatment both in calcified aorta and VSMC. The effect of ghrelin on autophagy induction and VC attenuation was prevented by AMPK inhibitor, compound C. Our results suggested that ghrelin improved autophagy through AMPK activation, which was resulted in VC amelioration. These data maybe throw light on prevention and therapy of VC. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Vascular dementia: Facts and controversies

    Directory of Open Access Journals (Sweden)

    Pavlović Aleksandra

    2013-01-01

    Full Text Available Vascular dementia (VaD is the second most frequent dementia after Alzheimer’s disease, and is diagnosed during lifetime in 20% of demented patients. Five­year survival rate in VaD is 39%, while it is estimated to be 75% in healthy persons of the same age. It is therefore important to make correct diagnosis of VaD early in the course of the disease. Risk factors for VaD are identical to stroke risk factors, and there are significant possibilities for the prevention of vascular cognitive decline. Cognitive decline develops acutely or step­by­step within three months after stroke, but more gradual progression of intellectual decline is also possible. Neurological examination can reveal pyramidal and extrapyramidal signs, pseudobulbar palsy, gait disturbance and urinary incontinence. Neuropsychological profile comprises the loss of cognitive set shifting, decline in word fluency, verbal learning difficulties, perseverations, difficulties in complex figure copying, and in patients with cortically located lesions also problems with speech and praxia. The basis of the diagnosis is, besides history, neurological examination and neuropsychological assessment, computed tomography and/ or magnetic resonance brain imaging. Vascular risk factors control is the most important measure in VaD prevention. Modern guidelines for the treatment of cognitive decline in VaD emphasize that donepezil can be useful in the improvement of cognitive status at the level of Class IIa recommendation at the level of evidence A, while memantine may be useful in patients with mixed VaD and Alzheimer’s disease dementia. [Projekat Ministarstva nauke Republike Srbije, br. 175022 i br. 175033

  4. Non-vascular surgical mediastinum

    International Nuclear Information System (INIS)

    Schiavon, S.; Trenaghi, P.; Nardini, S.; Pagan, V.

    1989-01-01

    A review was made of the chest X-ray features of 120 patients who underwent surgical treatment for mediastinal non-vascular pathologies over the past 12 years in the Mestre Hospital. A method of analysis is proposed which takes into account not only the differences between the immediate post-operative period and the follow-up, but also the anatomotopographic partition and the surgical practice. Normal and pathological patterns for both of the above periods are described. The ''dimness'' of the arial tracheogram is emphasized as a usefull and early sign of mediastinal recurrence

  5. Vascular comorbidities in multiple sclerosis

    DEFF Research Database (Denmark)

    Thormann, Anja; Magyari, Melinda; Koch-Henriksen, Nils

    2016-01-01

    To investigate the occurrence of vascular comorbidities before and after the clinical onset of multiple sclerosis. In this combined case-control and cohort study, all Danish born citizens with onset of multiple sclerosis 1980-2005 were identified from the Danish Multiple Sclerosis Registry...... and randomly matched with controls regarding year of birth, gender, and municipality on January 1st in the year of multiple sclerosis (MS) onset (index date). Individual-level information on comorbidities was obtained from several independent nationwide registries and linked to the study population by unique...

  6. Heritability of Retinal Vascular Fractals

    DEFF Research Database (Denmark)

    Vergmann, Anna Stage; Broe, Rebecca; Kessel, Line

    2017-01-01

    , the retinal vascular fractal dimension was measured using the box-counting method and compared within monozygotic and dizygotic twin pairs using Pearson correlation coefficients. Falconer's formula and quantitative genetic models were used to determine the genetic component of variation. Results: The mean...... fractal dimension did not differ statistically significantly between monozygotic and dizygotic twin pairs (1.505 vs. 1.495, P = 0.06), supporting that the study population was suitable for quantitative analysis of heritability. The intrapair correlation was markedly higher (0.505, P = 0...

  7. Technetium-99m labeled 1-(4-fluorobenzyl)-4-(2-mercapto-2-methyl-4-azapentyl)-4- (2-mercapto-2-methylp ropylamino)-piperidine and iodine-123 metaiodobenzylguanidine for studying cardiac adrenergic function: a comparison of the uptake characteristics in vascular smooth muscle cells and neonatal cardiac myocytes, and an investigation in rats

    International Nuclear Information System (INIS)

    Samnick, Samuel; Scheuer, Claudia; Muenks, Sven; El-Gibaly, Amr M.; Menger, Michael D.; Kirsch, Carl-Martin

    2004-01-01

    In developing technetium-99m-based radioligands for in vivo studies of cardiac adrenergic neurons, we compared the uptake characteristics of the 99m Tc-labeled 1-(4-fluorobenzyl)-4-(2-mercapto-2-methyl-4-azapentyl)-4- (2-mercapto-2-methylpropylamino)-piperidine ( 99m Tc-FBPBAT) with those of the clinically established meta-[ 123 I]iodobenzylguanidine ( 123 I-MIBG) in rat vascular smooth muscle cells and neonatal cardiac myocytes. Furthermore, the cardiac and extracardiac uptake of both radiopharmaceuticals was assessed in intact rats and in rats pretreated with various α- and β-adrenoceptor drugs, and adrenergic reuptake blocking agents. The uptake of 99m Tc-FBPBAT and 123 I-MIBG into vascular smooth muscle cells and neonatal cardiac myocytes was rapid; more than 85% of the radioactivity accumulation into the cells occurring within the first 3 minutes. Radioactivity uptake after a 60-minute incubation at 37 degree sign C (pH 7.4) varied from 15% to 65% of the total loaded activity per million cells. In all cases, 99m Tc-FBPBAT showed the higher uptake, relative to 123 I-MIBG, at any given cell concentration. The cellular uptake of 99m Tc-FBPBAT was lower at 4 degree sign C and 20 degree sign C than at 37 degree sign C. In contrast, the 123 I-MIBG uptake was only slightly temperature dependent. Inhibition experiments confirmed that the cellular uptake of 123 I-MIBG is mediated by the uptake-I carrier, whereas α 1 - and β 1 -adrenoceptors were predominantly involved in the uptake of 99m Tc-FBPBAT into the cardiovascular tissues. Biodistribution studies in rats showed that 99m Tc-FBPBAT accumulated in myocardium after intravenous injection. Radioactivity in rat heart amounted to 2.32% and 1.91% of the injected dose per gram at 15 and 60 minutes postinjection, compared with 3.10% and 2.21% injected dose per gram of tissue (%ID/g) in the experiment with 123 I-MIBG, respectively. Prazosin, urapidil, and metoprolol were as effective as treatment with other adrenergic

  8. Technetium-99m labeled 1-(4-fluorobenzyl)-4-(2-mercapto-2-methyl-4-azapentyl)-4- (2-mercapto-2-methylp ropylamino)-piperidine and iodine-123 metaiodobenzylguanidine for studying cardiac adrenergic function: a comparison of the uptake characteristics in vascular smooth muscle cells and neonatal cardiac myocytes, and an investigation in rats

    Energy Technology Data Exchange (ETDEWEB)

    Samnick, Samuel E-mail: rassam@uniklinik-saarland.de; Scheuer, Claudia; Muenks, Sven; El-Gibaly, Amr M.; Menger, Michael D.; Kirsch, Carl-Martin

    2004-05-01

    In developing technetium-99m-based radioligands for in vivo studies of cardiac adrenergic neurons, we compared the uptake characteristics of the {sup 99m}Tc-labeled 1-(4-fluorobenzyl)-4-(2-mercapto-2-methyl-4-azapentyl)-4- (2-mercapto-2-methylpropylamino)-piperidine ({sup 99m}Tc-FBPBAT) with those of the clinically established meta-[{sup 123}I]iodobenzylguanidine ({sup 123}I-MIBG) in rat vascular smooth muscle cells and neonatal cardiac myocytes. Furthermore, the cardiac and extracardiac uptake of both radiopharmaceuticals was assessed in intact rats and in rats pretreated with various {alpha}- and {beta}-adrenoceptor drugs, and adrenergic reuptake blocking agents. The uptake of {sup 99m}Tc-FBPBAT and {sup 123}I-MIBG into vascular smooth muscle cells and neonatal cardiac myocytes was rapid; more than 85% of the radioactivity accumulation into the cells occurring within the first 3 minutes. Radioactivity uptake after a 60-minute incubation at 37 degree sign C (pH 7.4) varied from 15% to 65% of the total loaded activity per million cells. In all cases, {sup 99m}Tc-FBPBAT showed the higher uptake, relative to {sup 123}I-MIBG, at any given cell concentration. The cellular uptake of {sup 99m}Tc-FBPBAT was lower at 4 degree sign C and 20 degree sign C than at 37 degree sign C. In contrast, the {sup 123}I-MIBG uptake was only slightly temperature dependent. Inhibition experiments confirmed that the cellular uptake of {sup 123}I-MIBG is mediated by the uptake-I carrier, whereas {alpha}{sub 1}- and {beta}{sub 1}-adrenoceptors were predominantly involved in the uptake of {sup 99m}Tc-FBPBAT into the cardiovascular tissues. Biodistribution studies in rats showed that {sup 99m}Tc-FBPBAT accumulated in myocardium after intravenous injection. Radioactivity in rat heart amounted to 2.32% and 1.91% of the injected dose per gram at 15 and 60 minutes postinjection, compared with 3.10% and 2.21% injected dose per gram of tissue (%ID/g) in the experiment with {sup 123}I

  9. The current approach to the diagnosis of vascular anomalies of the head and neck: A pictorial essay

    Energy Technology Data Exchange (ETDEWEB)

    Goei, Sinny; Singh, Aarti; Ghosh, Sujoy; Gupta, Sunta [Dept. of Oral Medicine and Radiology, Maulana Azad Institute of Dental Sciences, Delhi (India); Gupta, Swati; Prakash, Anjali [Dept. of Radiodiagnosis, Lok Nayak Jaiprakash Hospital, Delhi (India); Narang, Poonam [Dept. of Radiodiagnosis, Govind Ballabh Pant Hospital, Delhi (India)

    2015-06-15

    Throughout the years, various classifications have evolved for the diagnosis of vascular anomalies. However, it remains difficult to classify a number of such lesions. Because all hemangiomas were previously considered to involute, if a lesion with imaging and clinical characteristics of hemangioma does not involute, then there is no subclass in which to classify such a lesion, as reported in one of our cases. The recent classification proposed by the International Society for the Study of Vascular Anomalies (ISSVA, 2014) has solved this problem by including non-involuting and partially involuting hemangioma in the classification. We present here five cases of vascular anomalies and discuss their diagnosis in accordance with the ISSVA (2014) classification. A non-involuting lesion should not always be diagnosed as a vascular malformation. A non-involuting lesion can be either a hemangioma or a vascular malformation depending upon its clinicopathologic and imaging characteristics.

  10. The current approach to the diagnosis of vascular anomalies of the head and neck: A pictorial essay

    International Nuclear Information System (INIS)

    Goei, Sinny; Singh, Aarti; Ghosh, Sujoy; Gupta, Sunta; Gupta, Swati; Prakash, Anjali; Narang, Poonam

    2015-01-01

    Throughout the years, various classifications have evolved for the diagnosis of vascular anomalies. However, it remains difficult to classify a number of such lesions. Because all hemangiomas were previously considered to involute, if a lesion with imaging and clinical characteristics of hemangioma does not involute, then there is no subclass in which to classify such a lesion, as reported in one of our cases. The recent classification proposed by the International Society for the Study of Vascular Anomalies (ISSVA, 2014) has solved this problem by including non-involuting and partially involuting hemangioma in the classification. We present here five cases of vascular anomalies and discuss their diagnosis in accordance with the ISSVA (2014) classification. A non-involuting lesion should not always be diagnosed as a vascular malformation. A non-involuting lesion can be either a hemangioma or a vascular malformation depending upon its clinicopathologic and imaging characteristics

  11. Design and application of model for training ultrasound-guided vascular cannulation in pediatric patients.

    Science.gov (United States)

    Pérez-Quevedo, O; López-Álvarez, J M; Limiñana-Cañal, J M; Loro-Ferrer, J F

    2016-01-01

    Central vascular cannulation is not a risk-free procedure, especially in pediatric patients. Newborn and infants are small and low-weighted, their vascular structures have high mobility because of tissue laxity and their vessels are superficial and with small diameter. These characteristics, together with the natural anatomical variability and poor collaboration of small children, make this technique more difficult to apply. Therefore, ultrasound imaging is increasingly being used to locate vessels and guide vascular access in this population. (a) To present a model that simulates the vascular system for training ultrasound-guided vascular access in pediatrics patients; (b) to ultrasound-guided vascular cannulation in the model. The model consisted of two components: (a) muscular component: avian muscle, (b) vascular component: elastic tube-like structure filled with fluid. 864 ecoguided punctures was realized in the model at different vessel depth and gauge measures were simulated, for two medical operators with different degree of experience. The average depth and diameter of vessel cannulated were 1.16 (0.42)cm and 0.43 (0.1)cm, respectively. The average number of attempts was of 1.22 (0.62). The percentage of visualization of the needle was 74%. The most frequent maneuver used for the correct location, was the modification of the angle of the needle and the relocation of the guidewire in 24% of the cases. The average time for the correct cannulations was 41 (35.8)s. The more frequent complications were the vascular perforation (11.9%) and the correct vascular puncture without possibility of introducing the guidewire (1.2%). The rate of success was 96%. The model simulates the anatomy (vascular and muscular structures) of a pediatric patient. It is cheap models, easily reproducible and a useful tool for training in ultrasound-guided puncture and cannulation. Copyright © 2015 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

  12. The primary vascular dysregulation syndrome: implications for eye diseases

    Science.gov (United States)

    2013-01-01

    Vascular dysregulation refers to the regulation of blood flow that is not adapted to the needs of the respective tissue. We distinguish primary vascular dysregulation (PVD, formerly called vasospastic syndrome) and secondary vascular dysregulation (SVD). Subjects with PVD tend to have cold extremities, low blood pressure, reduced feeling of thirst, altered drug sensitivity, increased pain sensitivity, prolonged sleep onset time, altered gene expression in the lymphocytes, signs of oxidative stress, slightly increased endothelin-1 plasma level, low body mass index and often diffuse and fluctuating visual field defects. Coldness, emotional or mechanical stress and starving can provoke symptoms. Virtually all organs, particularly the eye, can be involved. In subjects with PVD, retinal vessels are stiffer and more irregular, and both neurovascular coupling and autoregulation capacity are reduced while retinal venous pressure is often increased. Subjects with PVD have increased risk for normal-tension glaucoma, optic nerve compartment syndrome, central serous choroidopathy, Susac syndrome, retinal artery and vein occlusions and anterior ischaemic neuropathy without atherosclerosis. Further characteristics are their weaker blood–brain and blood-retinal barriers and the higher prevalence of optic disc haemorrhages and activated astrocytes. Subjects with PVD tend to suffer more often from tinnitus, muscle cramps, migraine with aura and silent myocardial ischaemic and are at greater risk for altitude sickness. While the main cause of vascular dysregulation is vascular endotheliopathy, dysfunction of the autonomic nervous system is also involved. In contrast, SVD occurs in the context of other diseases such as multiple sclerosis, retrobulbar neuritis, rheumatoid arthritis, fibromyalgia and giant cell arteritis. Taking into consideration the high prevalence of PVD in the population and potentially linked pathologies, in the current article, the authors provide

  13. Vascular and renal function in experimental thyroid disorders.

    Science.gov (United States)

    Vargas, Félix; Moreno, Juan Manuel; Rodríguez-Gómez, Isabel; Wangensteen, Rosemary; Osuna, Antonio; Alvarez-Guerra, Miriam; García-Estañ, Joaquín

    2006-02-01

    This review focuses on the effects of thyroid hormones in vascular and renal systems. Special emphasis is given to the mechanisms by which thyroid hormones affect the regulation of body fluids, vascular resistance and, ultimately, blood pressure. Vascular function is markedly affected by thyroid hormones that produce changes in vascular reactivity and endothelial function in hyper- and hypothyroidism. The hypothyroid state is accompanied by a marked decrease in sensitivity to vasoconstrictors, especially to sympathetic agonists, alteration that may play a role in the reduced blood pressure of hypothyroid rats, as well as in the preventive effects of hypothyroidism on experimental hypertension. Moreover, in hypothyroid rats, the endothelium-dependent and nitric oxide donors vasodilation is reduced. Conversely, the vessels from hyperthyroid rats showed an increased endothelium-dependent responsiveness that may be secondary to the shear-stress induced by the hyperdynamic circulation, and that may contribute to the reduced vascular resistance characteristic of this disease. Thyroid hormones also have important effects in the kidney, affecting renal growth, renal haemodynamics, and salt and water metabolism. In hyperthyroidism, there is a resetting of the pressure-natriuresis relationship related to hyperactivity of the renin-angiotensin system, which contributes to the arterial hypertension associated with this endocrine disease. Moreover, thyroid hormones affect the development and/or maintenance of various forms of arterial hypertension. This review also describes recent advances in our understanding of thyroid hormone action on nitric oxide and oxidative stress in the regulation of cardiovascular and renal function and in the long-term control of blood pressure.

  14. CIRSE Vascular Closure Device Registry

    International Nuclear Information System (INIS)

    Reekers, Jim A.; Müller-Hülsbeck, Stefan; Libicher, Martin; Atar, Eli; Trentmann, Jens; Goffette, Pierre; Borggrefe, Jan; Zeleňák, Kamil; Hooijboer, Pieter; Belli, Anna-Maria

    2011-01-01

    Purpose: Vascular closure devices are routinely used after many vascular interventional radiology procedures. However, there have been no major multicenter studies to assess the safety and effectiveness of the routine use of closure devices in interventional radiology. Methods: The CIRSE registry of closure devices with an anchor and a plug started in January 2009 and ended in August 2009. A total of 1,107 patients were included in the registry. Results: Deployment success was 97.2%. Deployment failure specified to access type was 8.8% [95% confidence interval (95% CI) 5.0–14.5] for antegrade access and 1.8% (95% CI 1.1–2.9) for retrograde access (P = 0.001). There was no difference in deployment failure related to local PVD at the access site. Calcification was a reason for deployment failure in only 5.9 cm, and two vessel occlusions. Conclusion: The conclusion of this registry of closure devices with an anchor and a plug is that the use of this device in interventional radiology procedures is safe, with a low incidence of serious access site complications. There seems to be no difference in complications between antegrade and retrograde access and other parameters.

  15. Neuroradiological findings in vascular dementia

    Energy Technology Data Exchange (ETDEWEB)

    Guermazi, Ali; Miaux, Yves; Suhy, Joyce; Pauls, Jon; Lopez, Ria [Synarc, Inc., Department of Radiology Services, San Francisco, CA (United States); Rovira-Canellas, Alex [Hospital General Universitari Vall d' Hebron, Unita de Resonancia Magnetica, Barcelona (Spain); Posner, Holly [Eisai, Inc., Teaneck, NJ (United States)

    2007-01-15

    There are multiple diagnostic criteria for vascular dementia (VaD) that may define different populations. Utilizing the criteria of the National Institute of Neurological Disorders and Stroke and Association Internationale pour la Recherche et l'Enseignement en Neurosciences (NINDS-AIREN) has provided improved consistency in the diagnosis of VaD. The criteria include a table listing brain imaging lesions associated with VaD. The different neuroradiological aspects of the criteria are reviewed based on the imaging data from an ongoing large-scale clinical trial testing a new treatment for VaD. The NINDS-AIREN criteria were applied by a centralized imaging rater to determine eligibility for enrollment in 1,202 patients using brain CT or MRI. Based on the above data set, the neuroradiological features that are associated with VaD and that can result from cerebral small-vessel disease with extensive leukoencephalopathy or lacunae (basal ganglia or frontal white matter), or may be the consequence of single strategically located infarcts or multiple infarcts in large-vessel territories, are illustrated. These features may also be the consequence of global cerebral hypoperfusion, intracerebral hemorrhage, or other mechanisms such as genetically determined arteriopathies. Neuroimaging confirmation of cerebrovascular disease in VaD provides information about the topography and severity of vascular lesions. Neuroimaging may also assist with the differential diagnosis of dementia associated with normal pressure hydrocephalus, chronic subdural hematoma, arteriovenous malformation or tumoral diseases. (orig.)

  16. CIRSE Vascular Closure Device Registry

    Science.gov (United States)

    Müller-Hülsbeck, Stefan; Libicher, Martin; Atar, Eli; Trentmann, Jens; Goffette, Pierre; Borggrefe, Jan; Zeleňák, Kamil; Hooijboer, Pieter; Belli, Anna-Maria

    2010-01-01

    Purpose Vascular closure devices are routinely used after many vascular interventional radiology procedures. However, there have been no major multicenter studies to assess the safety and effectiveness of the routine use of closure devices in interventional radiology. Methods The CIRSE registry of closure devices with an anchor and a plug started in January 2009 and ended in August 2009. A total of 1,107 patients were included in the registry. Results Deployment success was 97.2%. Deployment failure specified to access type was 8.8% [95% confidence interval (95% CI) 5.0–14.5] for antegrade access and 1.8% (95% CI 1.1–2.9) for retrograde access (P = 0.001). There was no difference in deployment failure related to local PVD at the access site. Calcification was a reason for deployment failure in only 5.9 cm, and two vessel occlusions. Conclusion The conclusion of this registry of closure devices with an anchor and a plug is that the use of this device in interventional radiology procedures is safe, with a low incidence of serious access site complications. There seems to be no difference in complications between antegrade and retrograde access and other parameters. PMID:20981425

  17. Enhanced Recovery after Vascular Surgery

    Directory of Open Access Journals (Sweden)

    Milena D. Stojanovic

    2018-01-01

    Full Text Available The beginnings of the enhanced recovery after surgery (ERAS program were first developed for patients in colorectal surgery, and after it was established as the standard of care in this surgical field, it began to be applied in many others surgical areas. This is multimodal, evidence-based approach program and includes simultaneous optimization of preoperative status of patients, adequate selection of surgical procedure and postoperative management. The aim of this program is to reduce complications, the length of hospital stay and to improve the patients outcome. Over the past decades, special attention was directed to the postoperative management in vascular surgery, especially after major vascular surgery because of the great risk of multiorgan failure, such as: respiratory failure, myocardial infarction, hemodynamic instability, coagulopathy, renal failure, neurological disorders, and intra-abdominal complications. Although a lot of effort was put into it, there is no unique acceptable program for ERAS in this surgical field, and there is still a need to point out the factors responsible for postoperative outcomes of these patients. So far, it is known that special attention should be paid to already existing diseases, type and the duration of the surgical intervention, hemodynamic and fluid management, nutrition, pain management, and early mobilization of patients.

  18. Vascular access for home haemodialysis.

    Science.gov (United States)

    Al Shakarchi, Julien; Day, C; Inston, N

    2018-03-01

    Home haemodialysis has been advocated due to improved quality of life. However, there are very little data on the optimum vascular access for it. A retrospective cohort study was carried on all patients who initiated home haemodialysis between 2011 and 2016 at a large university hospital. Access-related hospital admissions and interventions were used as primary outcome measures. Our cohort consisted of 74 patients. On initiation of home haemodialysis, 62 individuals were using an arteriovenous fistula as vascular access, while the remaining were on a tunnelled dialysis catheter. Of the 12 patients who started on a tunnelled dialysis catheter, 5 were subsequently converted to either an arteriovenous fistula ( n = 4) or an arteriovenous graft ( n = 1). During the period of home haemodialysis use, four arteriovenous fistula failed or thrombosed with patients continuing on home haemodialysis using an arteriovenous graft ( n = 3) or a tunnelled dialysis catheter ( n = 1). To maintain uninterrupted home haemodialysis, interventional rates were 0.32 per arteriovenous fistula/arteriovenous graft access-year and 0.4 per tunnelled dialysis catheter access-year. Hospital admission rates for patients on home haemodialysis were 0.33 per patient-year. Our study has shown that home haemodialysis can be safely and independently performed at home within a closely managed home haemodialysis programme. The authors also advocate the use of arteriovenous fistulas for this cohort of patients due to both low complication and intervention rates.

  19. Vascular emergencies in liver trauma

    Energy Technology Data Exchange (ETDEWEB)

    Taourel, P. [Centre Hospitalier Universitaire Lapeyronie, Montpellier (France)], E-mail: p-taourel@chu-montpellier.fr; Vernhet, H. [Centre Hospitalier Universitaire Arnaud de Villeneuve, Montpellier (France); Suau, A.; Granier, C. [Centre Hospitalier Universitaire Lapeyronie, Montpellier (France); Lopez, F.M. [Centre Hospitalier Universitaire, Nimes (France); Aufort, S. [Centre Hospitalier Universitaire Lapeyronie, Montpellier (France)

    2007-10-15

    The use of CT in the diagnosis and management of liver trauma is responsible for the shift from routine surgical versus non-surgical treatment in the management of traumatic liver injuries, even when they are of high grade. The main cause of compli cation and of death in liver trauma is related to vascular injury. The goal of this review focussed on the vascular complications of liver trauma is to describe the elementary lesions shown by CT in liver trauma including laceration, parenchymal hematoma and contusions, partial devascularisation, subcapsular hematomas, hemoperitoneum, active bleeding, pseudoaneurysm of the hepatic artery, bile leak, and periportal oedema, to illustrate the possible pitfalls in CT diagnosis of liver trauma and to underline the key-points which may absolutely be present in a CT report of liver trauma. Then we will remind the grading system based on the CT features and we will analyze the interest and limitations of such grading systems. Last we will discuss the diagnostic strategy at the early phase in patients with suspected liver trauma according to their clinical conditions and underline the conditions of arterial embolization, and then we will discuss the diagnosis strategy at the delayed phase according to the suspected complications.

  20. Vascular emergencies in liver trauma

    International Nuclear Information System (INIS)

    Taourel, P.; Vernhet, H.; Suau, A.; Granier, C.; Lopez, F.M.; Aufort, S.

    2007-01-01

    The use of CT in the diagnosis and management of liver trauma is responsible for the shift from routine surgical versus non-surgical treatment in the management of traumatic liver injuries, even when they are of high grade. The main cause of compli cation and of death in liver trauma is related to vascular injury. The goal of this review focussed on the vascular complications of liver trauma is to describe the elementary lesions shown by CT in liver trauma including laceration, parenchymal hematoma and contusions, partial devascularisation, subcapsular hematomas, hemoperitoneum, active bleeding, pseudoaneurysm of the hepatic artery, bile leak, and periportal oedema, to illustrate the possible pitfalls in CT diagnosis of liver trauma and to underline the key-points which may absolutely be present in a CT report of liver trauma. Then we will remind the grading system based on the CT features and we will analyze the interest and limitations of such grading systems. Last we will discuss the diagnostic strategy at the early phase in patients with suspected liver trauma according to their clinical conditions and underline the conditions of arterial embolization, and then we will discuss the diagnosis strategy at the delayed phase according to the suspected complications

  1. Vascularized bone transplant chimerism mediated by vascular endothelial growth factor.

    Science.gov (United States)

    Willems, Wouter F; Larsen, Mikko; Friedrich, Patricia F; Bishop, Allen T

    2015-01-01

    Vascular endothelial growth factor (VEGF) induces angiogenesis and osteogenesis in bone allotransplants. We aim to determine whether bone remodeling in VEGF-treated bone allotransplants results from repopulation with circulation-derived autogenous cells or survival of allogenic transplant-derived cells. Vascularized femoral bone transplants were transplanted from female Dark Agouti rats (DA;RT1(a) ) to male Piebald Viral Glaxo (PVG;RT1(c) ). Arteriovenous bundle implantation and short-term immunosuppression were used to maintain cellular viability. VEGF was encapsulated in biodegradable microspheres and delivered intramedullary in the experimental group (n = 22). In the control group (n = 22), no VEGF was delivered. Rats were sacrificed at 4 or 18 weeks. Laser capture microdissection of bone remodeling areas was performed at the inner and outer cortex. Sex-mismatched genes were quantified with reverse transcription-polymerase chain reaction to determine the amount of male cells to total cells, defined as the relative expression ratio (rER). At 4 weeks, rER was significantly higher at the inner cortex in VEGF-treated transplants as compared to untreated transplants (0.622 ± 0.225 vs. 0.362 ± 0.081, P = 0.043). At 4 weeks, the outer cortex in the control group had a significantly higher rER (P = 0.038), whereas in the VEGF group, the inner cortex had a higher rER (P = 0.015). Over time, in the outer cortex the rER significantly increased to 0.634 ± 0.106 at 18 weeks in VEGF-treated rats (P = 0.049). At 18 weeks, the rER was >0.5 at all cortical areas in both groups. These in vivo findings suggest a chemotactic effect of intramedullary applied VEGF on recipient-derived bone and could imply that more rapid angiogenesis of vascularized allotransplants can be established with microencapsulated VEGF. © 2014 Wiley Periodicals, Inc.

  2. World Federation of Vascular Societies: presidential address

    DEFF Research Database (Denmark)

    Sillesen, Henrik Hegaard

    2010-01-01

    The presidential address describes briefly the history of the World Federation for Vascular Societies (WFVS) and its objectives. Vascular Surgery today includes interventional procedures (open surgical and endovascular) in addition to risk factor reduction and medical treatment. It is equally imp...... throughout the world. In addition, for introduction of new treatments, training issues and dissemination of science a global organisation like the WFVS is needed.......The presidential address describes briefly the history of the World Federation for Vascular Societies (WFVS) and its objectives. Vascular Surgery today includes interventional procedures (open surgical and endovascular) in addition to risk factor reduction and medical treatment. It is equally...

  3. Benign vascular lesions of bone: radiologic and pathologic features

    Energy Technology Data Exchange (ETDEWEB)

    Wenger, D.E.; Wold, L.E. [Mayo Foundation, Rochester, MN (United States)

    2000-02-01

    The benign vascular tumors of bone represent a diverse group of tumors that can present with a broad spectrum of clinical signs and symptoms. They can also present a significant diagnostic challenge due to their widely variable radiographic imaging and histologic features. Some of the tumors manifest as clearly benign lesions with tissue-specific diagnostic imaging features, while others have non-specific imaging features that may simulate malignant neoplasm. This article will provide a review of the nomenclature and the characteristic radiographic and pathologic features of the benign vascular lesions of bone. The information will aid in improving our diagnostic accuracy and enhance our understanding of the biologic potential of this diverse group of osseous lesions. (orig.)

  4. Benign vascular lesions of bone: radiologic and pathologic features

    International Nuclear Information System (INIS)

    Wenger, D.E.; Wold, L.E.

    2000-01-01

    The benign vascular tumors of bone represent a diverse group of tumors that can present with a broad spectrum of clinical signs and symptoms. They can also present a significant diagnostic challenge due to their widely variable radiographic imaging and histologic features. Some of the tumors manifest as clearly benign lesions with tissue-specific diagnostic imaging features, while others have non-specific imaging features that may simulate malignant neoplasm. This article will provide a review of the nomenclature and the characteristic radiographic and pathologic features of the benign vascular lesions of bone. The information will aid in improving our diagnostic accuracy and enhance our understanding of the biologic potential of this diverse group of osseous lesions. (orig.)

  5. [Immunologic problems in vascular homografts].

    Science.gov (United States)

    D'Addato, M; Mirelli, M

    2001-01-01

    Fresh arterial homografts are immunogenic, inducing in recipient a strong immune response specifically directed against the antigens of the donor graft. The initial immune response seems to be cellular (lymphocytotoxic) and the late reaction humoral (antibody), even if they are strictly correlated. Immunosuppressive therapy reduce the immune reaction, but this response is dose-related. Implanted arterial homografts induce a donor-specific response similar to chronic reaction, which occurs in the recipients of vascularized solid-organ allografts. Therefore, in arterial transplantation, ABO compatibility and negative crossmatch should be respected. Effort should be made to curb the immune response by prospective cross-matching, immunosuppressive therapy and preoperative manipulation of homografts to reduce their antigenicity.

  6. Heritability of Retinal Vascular Fractals

    DEFF Research Database (Denmark)

    Vergmann, Anna Stage; Broe, Rebecca; Kessel, Line

    2017-01-01

    Purpose: To determine the genetic contribution to the pattern of retinal vascular branching expressed by its fractal dimension. Methods: This was a cross-sectional study of 50 monozygotic and 49 dizygotic, same-sex twin pairs aged 20 to 46 years. In 50°, disc-centered fundus photographs, the reti...... fractal dimension did not differ statistically significantly between monozygotic and dizygotic twin pairs (1.505 vs. 1.495, P = 0.06), supporting that the study population was suitable for quantitative analysis of heritability. The intrapair correlation was markedly higher (0.505, P = 0.......0002) in monozygotic twins than in dizygotic twins (0.108, P = 0.46), corresponding to a heritability h2 for the fractal dimension of 0.79. In quantitative genetic models, dominant genetic effects explained 54% of the variation and 46% was individually environmentally determined. Conclusions: In young adult twins...

  7. Vascular anastomosis by Argon Laser

    International Nuclear Information System (INIS)

    Gomes, O.M.; Macruz, R.; Armelin, E.; Brum, J.M.G.; Ribeiro, M.P.; Mnitentog, J.; Verginelli, G.; Pileggi, F.; Zerbini, E.J.

    1982-01-01

    Twenty four mongrel dogs, wheighing 13 to 24 kilograms were studied. After anesthesia, intubation and controlled ventilation, they were submitted to three types of vascular anastomosis: Group I - eight dogs with saphenous vein inter-carotid arteries by-pass: Group II - eight dogs with left mammary artery - left anterior descending coronary artery by-pass; Group III - eight dogs with venovenous anastomosis. In all groups 0.8 to 15 watts of Argon Laser power was applied to a total time of 90 to 300 seconds. The lower power for venovenous anastomosis and the greater for the arterial ones. The mean valves of resistence of the Laser anastomosis to pressure induced rupture was 730 mmHg in the immediate post operative study, and superior to 2.500 mmHg 30 days after. No signs of occlusion was demonstrated at the anastomosis sites by the angiographic and anathomo-patological study performed. (Author) [pt

  8. Vascular targeting with peptide libraries

    Energy Technology Data Exchange (ETDEWEB)

    Pasqualini, R. [La Jolla Cancer Research Center The Burnham Inst., La Jolla CA (United States)

    1999-06-01

    The authors have developed an 'in vivo' selection system in which phage capable of selective homing to different tissues are recovered from a phage display peptide library following intravenous administration. Using this strategy, they have isolate several organ and tumor-homing peptides. They have shown that each of those peptides binds of different receptors that are selectively expressed on the vasculature of the target tissue. The tumor-homing peptides bind to receptors that are up regulated in tumor angiogenic vasculature. Targeted delivery of doxorubicin to angiogenic vasculature using these peptides in animals models decrease toxicity and increased the therapeutic efficacy of the drug. Vascular targeting may facilitate the development of other treatment strategies that rely on inhibition of angio genesis and lead to advances to extend the potential for targeting of drugs, genes and radionuclides in the context of many diseases.

  9. Vascular Morphodynamics During Secondary Growth.

    Science.gov (United States)

    de Reuille, Pierre Barbier; Ragni, Laura

    2017-01-01

    Quantification of vascular morphodynamics during secondary growth has been hampered by the scale of the process. Even in the tiny model plant Arabidopsis thaliana, the xylem can include more than 2000 cells in a single cross section, rendering manual counting impractical. Moreover, due to its deep location, xylem is an inaccessible tissue, limiting live imaging. A novel method to visualize and measure secondary growth progression has been proposed: "the Quantitative Histology" approach. This method is based on a detailed anatomical atlas, and image segmentation coupled with machine learning to automatically extract cell shapes and identify cell type. Here we present a new version of this approach, with a user-friendly interface implemented in the open source software LithoGraphX.

  10. Adiposity, adipocytokines & microvesicles in the etiology of vascular disease

    NARCIS (Netherlands)

    Kanhai, D.A.N.I.S.

    2013-01-01

    Vascular disease, in this thesis the terms vascular and cardiovascular are used interchangeably, is the number 1 cause of death worldwide. In 2008, 30% of all mortality had a vascular origin. Vascular mortality rates after a first manifestation of vascular disease are decreasing in Western society,

  11. FPGA controlled artificial vascular system

    Directory of Open Access Journals (Sweden)

    Laqua D.

    2015-09-01

    Full Text Available Monitoring the oxygen saturation of an unborn child is an invasive procedure, so far. Transabdominal fetal pulse oximetry is a promising method under research, used to estimate the oxygen saturation of a fetus noninvasively. Due to the nature of the method, the fetal information needs to be extracted from a mixed signal. To properly evaluate signal processing algorithms, a phantom modeling fetal and maternal blood circuits and tissue layers is necessary. This paper presents an improved hardware concept for an artificial vascular system, utilizing an FPGA based CompactRIO System from National Instruments. The experimental model to simulate the maternal and fetal blood pressure curve consists of two identical hydraulic circuits. Each of these circuits consists of a pre-pressure system and an artificial vascular system. Pulse curves are generated by proportional valves, separating these two systems. The dilation of the fetal and maternal artificial vessels in tissue substitutes is measured by transmissive and reflective photoplethysmography. The measurement results from the pressure sensors and the transmissive optical sensors are visualized to show the functionality of the pulse generating systems. The trigger frequency for the maternal valve was set to 1 per second, the fetal valve was actuated at 0.7 per second for validation. The reflective curve, capturing pulsations of the fetal and maternal circuit, was obtained with a high power LED (905 nm as light source. The results show that the system generates pulse curves, similar to its physiological equivalent. Further, the acquired reflective optical signal is modulated by the alternating diameter of the tubes of both circuits, allowing for tests of signal processing algorithms.

  12. Associations between vascular co-morbidities and depression in insulin-naive diabetes patients

    DEFF Research Database (Denmark)

    Koopmans, B; Pouwer, F; de Bie, Rob A

    2009-01-01

    AIMS/HYPOTHESIS: The aim of the study was to determine the prevalence of depression in insulin-naive diabetes patients and to investigate the associations between different forms of vascular co-morbidity and depression. METHODS: Cross-sectional data were used from a primary-care sample of 1......,269 insulin-naive (i.e. not using insulin therapy) diabetes patients participating in the DIAZOB Primary Care Diabetes study. Demographics, vascular co-morbidities, clinical and lifestyle characteristics, and psychosocial factors were assessed. Depression symptoms were measured with the Edinburgh Depression.......2% vs 10.0%). Single vascular co-morbidities were not associated with increased rates of depression. The final model predicting depression included: having multiple vascular co-morbidities compared with none; having less social support; having experienced a recent stressful life event; female sex...

  13. Selected biological markers in various vascular lesions of the head and neck

    Directory of Open Access Journals (Sweden)

    Zuzanna Gronkiewicz

    2014-10-01

    Full Text Available Vascular anomalies are divided according to the contemporary system of classification into two groups: tumors and malformations. However, there is no consensus on juvenile angiofibroma’s place in that system. The general characteristics of selected markers of angiogenesis and tissue remodeling are presented in the series in the context of current knowledge in the field of pathophysiology of vascular lesions. The mentioned markers are currently the subjects of multidirectional studies in oncology, as they take part in the process of neoangiogenesis and proliferation of tumors. Nevertheless, they have not been widely examined in vascular lesions. The indirect goal of that series is to indicate the possible research direction on vascular lesions to determine their molecular profile, to create a more specific system of classification, and above all to develop new diagnostic and treatment methods.

  14. Dynamics of nephron-vascular network

    DEFF Research Database (Denmark)

    Postnov, Dmitry; Postnov, D E; Marsh, D J

    2012-01-01

    The paper presents a modeling study of the spatial dynamics of a nephro-vascular network consisting of individual nephrons connected via a tree-like vascular branching structure. We focus on the effects of nonlinear mechanisms that are responsible for the formation of synchronous patterns in order...

  15. Imaging of the peripheral vascular system

    International Nuclear Information System (INIS)

    Gould, S.A.; Pond, G.D.; Pinsky, S.; Moss, G.S.; Srikantaswamy, S.; Ryo, U.Y.

    1984-01-01

    This book is limited neither to the peripheral vascular system nor to diagnostic imaging techniques. Its 18 chapters cover nonimaging blood-flow techniques (Doppler ultrasound, plethysmography) as well as noninvasive and invasive imaging techniques (ultrasound, computed tomography, radionuclide digital-subtraction angiography, and contrast angiography). These are applied not only to the peripheral vascular system but also to the aorta and vena cava

  16. Biomarkers of drug-induced vascular injury

    International Nuclear Information System (INIS)

    Brott, D.; Gould, S.; Jones, H.; Schofield, J.; Prior, H.; Valentin, J.P; Bjurstrom, S.; Kenne, K.; Schuppe-Koistinen, I.; Katein, A.; Foster-Brown, L.; Betton, G.; Richardson, R.; Evans, G.; Louden, C.

    2005-01-01

    In pre-clinical safety studies, drug-induced vascular injury is an issue of concern because there are no obvious diagnostic markers for pre-clinical or clinical monitoring and there is an intellectual gap in our understanding of the pathogenesis of this lesion. While vasodilatation and increased shear stress appear to play a role, the exact mechanism(s) of injury to the primary targets, smooth muscle and endothelial cells are unknown. However, evaluation of novel markers for potential clinical monitoring with a mechanistic underpinning would add value in risk assessment and management. This mini review focuses on the progress to identify diagnostic markers of drug-induced vascular injury. Von Willebrand factor (vWF), released upon perturbation of endothelial cells, is transiently increased in plasma prior to morphological evidence of damage in dogs or rats treated with vascular toxicants. Therefore, vWF might be a predictive biomarker of vascular injury. However, vWF is not an appropriate biomarker of lesion progression or severity since levels return to baseline values when there is morphological evidence of injury. A potential mechanistically linked biomarker of vascular injury is caveolin-1. Expression of this protein, localized primarily to smooth muscle and endothelial cells, decreases with the onset of vascular damage. Since vascular injury involves multiple mediators and cell types, evaluation of a panel rather than a single biomarker may be more useful in monitoring early and severe progressive vascular injury

  17. Reconstructive vascular surgery below the knee

    DEFF Research Database (Denmark)

    Rasmussen, L B; Jelnes, R; Sager, P

    1986-01-01

    In a series of 38 consecutive patients with advanced peripheral vascular disease (i.e. rest pain) reconstructive vascular surgery was performed with the distal anastomosis below the knee. Ankle/arm pressure index (AAI) was 0.28 (0.11-0.47) preoperatively; accumulated graft patency rate was 0.47 (SD...

  18. Vascular dementia | Connor | African Journal of Psychiatry

    African Journals Online (AJOL)

    Vascular dementia (VaD) is a common but heterogeneous condition in which there is a clear temporal relationship between the dementia and vascular disease. It may result from multiple large or small vessel strokes or a single strategic stroke. Subcortical ischaemic VaD includes multiple lacunes and subcortical ...

  19. PanVascular medicine. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Lanzer, Peter (ed.) [Health Care Center Bitterfeld (Germany). Division of Cardiovascular Disease

    2015-06-01

    Vascular management and care has become a truly multidisciplinary enterprise as the number of specialists involved in the treatment of patients with vascular diseases has steadily increased. While in the past, treatments were delivered by individual specialists, in the twenty-first century a team approach is without doubt the most effective strategy. In order to promote professional excellence in this dynamic and rapidly evolving field, a shared knowledge base and interdisciplinary standards need to be established. Pan Vascular Medicine, 2nd edition has been designed to offer such an interdisciplinary platform, providing vascular specialists with state-of-the art descriptive and procedural knowledge. Basic science, diagnostics, and therapy are all comprehensively covered. In a series of succinct, clearly written chapters, renowned specialists introduce and comment on the current international guidelines and present up-to-date reviews of all aspects of vascular care.

  20. Using Polymeric Scaffolds for Vascular Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Alida Abruzzo

    2014-01-01

    Full Text Available With the high occurrence of cardiovascular disease and increasing numbers of patients requiring vascular access, there is a significant need for small-diameter (<6 mm inner diameter vascular graft that can provide long-term patency. Despite the technological improvements, restenosis and graft thrombosis continue to hamper the success of the implants. Vascular tissue engineering is a new field that has undergone enormous growth over the last decade and has proposed valid solutions for blood vessels repair. The goal of vascular tissue engineering is to produce neovessels and neoorgan tissue from autologous cells using a biodegradable polymer as a scaffold. The most important advantage of tissue-engineered implants is that these tissues can grow, remodel, rebuild, and respond to injury. This review describes the development of polymeric materials over the years and current tissue engineering strategies for the improvement of vascular conduits.

  1. Postoperative radiographic evaluation of vascularized fibular grafts

    International Nuclear Information System (INIS)

    Manaster, B.J.; Coleman, D.A.; Bell, D.A.

    1989-01-01

    This paper reports on thirty-five patients with free vascularized fibular grafts examined postoperatively with plain radiography. Early graft incorporation is seen as a fuzziness of the cortex at the site of its insertion into the host bone. Causes of failure in grafting for bone defects include graft fracture, hardware failure, and infection. A high percentage of complications or at least delayed unions occurred when vascularized fibular grafts were used to fill defects in the lower extremity. Conversely, upper extremity defects bridged by vascularized grafts heal quickly and hypertrophy. Vascularized grafts placed in the femoral head and neck for a vascular necrosis incorporate early on their superior aspect. The osseous tunnel in which they are placed is normally wider than the graft and often becomes sclerotic; this appearance does not represent nonunion

  2. PanVascular medicine. 2. ed.

    International Nuclear Information System (INIS)

    Lanzer, Peter

    2015-01-01

    Vascular management and care has become a truly multidisciplinary enterprise as the number of specialists involved in the treatment of patients with vascular diseases has steadily increased. While in the past, treatments were delivered by individual specialists, in the twenty-first century a team approach is without doubt the most effective strategy. In order to promote professional excellence in this dynamic and rapidly evolving field, a shared knowledge base and interdisciplinary standards need to be established. Pan Vascular Medicine, 2nd edition has been designed to offer such an interdisciplinary platform, providing vascular specialists with state-of-the art descriptive and procedural knowledge. Basic science, diagnostics, and therapy are all comprehensively covered. In a series of succinct, clearly written chapters, renowned specialists introduce and comment on the current international guidelines and present up-to-date reviews of all aspects of vascular care.

  3. Sonic Rarefaction Wave Low Recoil Gun

    National Research Council Canada - National Science Library

    Kathe, E

    2002-01-01

    A principal challenge faced by the U.S. Army TACOM-ARDEC Benet Laboratories in the design of armaments for lightweight future fighting vehicles with lethality overmatch is mitigating the deleterious effects of large caliber cannon recoil...

  4. Hysteresis rarefaction in the Riemann problem

    Czech Academy of Sciences Publication Activity Database

    Krejčí, Pavel

    2008-01-01

    Roč. 138, - (2008), s. 1-10 ISSN 1742-6588. [International Workshop on Multi-Rate Processes and Hysteresis. Cork , 31.03.2008-05.04.2008] Institutional research plan: CEZ:AV0Z10190503 Keywords : Preisach hysteresis * Riemann problem Subject RIV: BA - General Mathematics http://iopscience.iop.org/1742-6596/138/1/012010

  5. [Gastric vascular lesions in cirrhosis: gastropathy and antral vascular ectasia].

    Science.gov (United States)

    Casas, Meritxell; Calvet, Xavier; Vergara, Mercedes; Bella, Maria Rosa; Junquera, Félix; Martinez-Bauer, Eva; Campo, Rafael

    2015-02-01

    Portal hypertensive gastropathy (GHP) is a complication of portal hypertension usually associated with liver cirrhosis. The pathogenesis is unclear but the presence of portal hypertension is an essential factor for its development. GHP may be asymptomatic or present as gastrointestinal bleeding or iron deficiency anemia. Endoscopic lesions vary from a mosaic pattern to diffuse red spots; the most common location is the fundus. Treatment is indicated when there is acute or chronic bleeding, as secondary prophylaxis. There is insufficient evidence to recommend primary prophylaxis in patients who have never bled. Drugs that decrease portal pressure, such as non-cardioselective beta-blockers, and/or endoscopic ablative treatments, such as argon-beam coagulation, may be used. The role of transarterial intrahepatic portosystemic shunt) or bypass surgery has been insufficiently analyzed. Antral vascular ectasia (EVA) is a rare entity in liver cirrhosis, whose pathophysiology is still unknown. Clinical presentation is similar to that of GHP and endoscopy usually shows red spots in the antrum. Biopsy is often required to differentiate EVA from GHP. There is no effective medical therapy, so endoscopic ablative therapy and, in severe cases, antrectomy are recommended. Copyright © 2014 Elsevier España, S.L.U. and AEEH y AEG. All rights reserved.

  6. Bletilla colloid as a vascular embolization agent: experimental studies

    International Nuclear Information System (INIS)

    Zheng Chuansheng; Feng Gansheng; Zhang Yanfang

    1998-01-01

    Purpose: To study the efficacy, safety and related characteristics of bletilla colloid as a vascular embolization agent. Materials and methods: The authors prepared bletilla colloid as a vascular embolization agent from the stem tubers of bletilla of Chinese medicinal herb. Related characteristics of bletilla colloid were studied. In four pigs hepatic arterial embolization was performed with the bletilla colloid. Results: The bletilla colloid was a homogenous viscous colloid whose relative viscosity was 2324.6 mm 2 /s. It was easily injected through 4-F catheter and hyperattenuating under fluoroscopy, meanwhile, with good histocompatibility and hemo-compatibility, without pyrogenetic response and toxicity. In vitro, the mixture of bletilla colloid and MMC did not produce separation and suspension phenomena but released 50% of MMC at 1.8h and 100% at 3.4h. The bletilla colloid mainly embolized peripheral arteries, maintaining occlusion for 5 weeks and without formation of collateral circulation. The injuries of normal hepatic tissues were slight, without hepatic cytonecrosis. Conclusions: Bletilla colloid, safe and effective in use with angioembolic function and characteristics of carrier and slow-release, is a potential peripheral embolization agent

  7. Research progress of vascular change after TACE in hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Kang Zhen; Xiao Enhua

    2013-01-01

    Mortality rate of hepatocellular carcinoma is high. The majority of the patients are diagnosed in advanced stage and lose surgical opportunities. Many studies have reported transcatheter arterial chemoembolization (TACE) is an effective treatment for unresectable hepatocellular carcinoma, and recommended TACE as a standard treatment for hepatocellular carcinoma of Barcelona Clinical Liver Cancer staging (BCLC staging) B. However, TACE can hardly fully embolize tumor blood supply, TACE postoperative hemodynamics and angiogenesis can induce tumor recurrence and metastasis. This paper reviewed characteristics of vascular changes, mechanisms, diagnosis and treatment methods, new progress in the field of hepatocellular carcinoma after TACE. (authors)

  8. Diversity of vascular plants of Piestany and surroundings

    International Nuclear Information System (INIS)

    Penzesova, A.; Galusova, T.

    2013-01-01

    In the present work is a summary of the results of floristic research aimed at determining diversity of vascular plants of Piestany and its surroundings. Plant taxa we determined using the designation keys. We have compiled a list of plant species occurring in the monitored area, we evaluated the selected botanical-phytogeographical characteristics of flora, we've put together a list of local protected, endangered and rare species and a list of local invasive and expansive species according to sources. (Authors)

  9. Vascular elastic photoacoustic tomography in humans

    Science.gov (United States)

    Hai, Pengfei; Zhou, Yong; Liang, Jinyang; Li, Chiye; Wang, Lihong V.

    2016-03-01

    Quantification of vascular elasticity can help detect thrombosis and prevent life-threatening conditions such as acute myocardial infarction or stroke. Here, we propose vascular elastic photoacoustic tomography (VE-PAT) to measure vascular elasticity in humans. VE-PAT was developed by incorporating a linear-array-based photoacoustic computed tomography system with a customized compression stage. By measuring the deformation of blood vessels under uniaxial loading, VE-PAT was able to quantify the vascular compliance. We first demonstrated the feasibility of VE-PAT in blood vessel phantoms. In large vessel phantoms, VE-PAT detected a decrease in vascular compliance due to simulated thrombosis, which was validated by a standard compression test. In small blood vessel phantoms embedded 3 mm deep in gelatin, VE-PAT detected elasticity changes at depths that are difficult to image using other elasticity imaging techniques. We then applied VE-PAT to assess vascular compliance in a human subject and detected a decrease in vascular compliance when an occlusion occurred downstream from the measurement point, demonstrating the potential of VE-PAT in clinical applications such as detection of deep venous thrombosis.

  10. [A new specialty is born: Vascular medicine].

    Science.gov (United States)

    Laroche, J-P

    2016-05-01

    On the 4th of December 2015, the French authorities officially recognized the birth of a specialty in vascular medicine entitled CO-DES cardiology-vascular/vascular Medicine. France is the 7th country to obtain this specialty after Switzerland, Germany, Austria, Czech Republic, Slovakia and Slovenia, six countries in the EEC. It has taken years to achieve a long but exciting experience: we went from hopes to disappointments, sometimes with the blues, but lobbying helping… with sustained confidence. This article tells the story of 30 years of struggle to achieve this vascular medicine specialty. Gaston Bachelard wrote: "Nothing is obvious, nothing is given, all is built." For the construction of vascular medicine, we had to overcome many obstacles, nothing was given to us, everything was conquered. Beware "The specialist is one who knows more and more things about an increasingly restricted field, up to 'knowing everything about nothing"' recalled Ralph Barton Ferry, philosopher; so there is room for modesty and humility but also convictions. The physical examination will remain the basis of our exercise. But let us recall the contributions of all those vascular physicians who practiced in the past, together with those currently active, who built day after day, year after year, a vascular medicine of quality. It is because of the trust of our colleagues and our patients that we can occupy the place that is ours today. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  11. Diagnosis and management of vascular diseases

    International Nuclear Information System (INIS)

    Fan Xindong; Zheng Lianzhou

    2011-01-01

    Vascular disorders mainly include hemangiomas and vascular malformations, and constitute some of the most difficult diagnostic and therapeutic enigmas that can be encountered in the clinical practice. The clinical presentations are extremely variable and can range from an asymptomatic birthmark to life-threatening congestive heart failure. Attributing any of these extremely varied symptoms that a patients may present with to a vascular malformation may be a challenge to the most experienced clinical. This problem is compounded by the extreme rarity of these vascular lesions. If a clinician meets such a patient once every few years, it will be extremely difficult for the physicians to gain a steep learning curve. In such circumstances, it is difficult to formulate a standard of diagnosis and treatment for these vascular disorders. This paper aims to make a comprehensive and detailed description of the classification and diagnosis of the vascular disorders, the common used embolization agents, the concepts of interventional diagnosis and management and the therapies of various hemangiomas and vascular malformations. (authors)

  12. Temporal deconvolution of vascular plant signatures delivered to coastal sediments

    Science.gov (United States)

    Vonk, J.; Drenzek, N. J.; Hughen, K. A.; Stanley, R.; Montluçon, D. B.; McIntyre, C.; Southon, J. R.; Santos, G.; Andersson, A.; Sköld, M.; Eglinton, T. I.

    2017-12-01

    Presently, relatively little is known about the amount of time that lapses between the photosynthetic fixation of carbon by vascular land plants and its incorporation into the marine sedimentary record. It is clear that there are multiple potential intermediate storage pools and transport trajectories that vascular plant carbon may experience, and the age of vascular plant carbon accumulating in marine sediments will reflect these different pre-depositional histories. Here we use molecular-level radiocarbon (14C) analysis to develop down-core 14C profiles for higher plant leaf wax-derived fatty acids isolated from sediments from three sites across a 60-degrees latitudinal gradient (Cariaco Basin, Saanich Inlet, and Mackenzie Delta). The sediment profiles were used as a direct measure of the storage and transport times experienced by these biomolecular tracer compounds. Residence times are evaluated by comparing these records to the 14C history of atmospheric CO2. Using a modeling framework, we conclude that there is, in addition to a variable "young" pool, a millennial pool of compounds that consists of 49-78 % of the fractional contribution of organic carbon (OC) that exhibits variable ages for the different depositional settings. For the Mackenzie Delta sediments, we find a mean age of the millennial pool of 28 ky, suggesting pre-aging in permafrost soils, whereas the millennial pool in Saanich Inlet and Cariaco Basin sediments is younger with 7.9 and 2.4-3.2 ky, respectively, suggesting limited storage in terrestrial reservoirs. The "young" pool, conditionally defined as vascular plant C in deltaic and marine settings undergoes pre-aging in terrestrial reservoirs. The age distribution, reflecting storage and transport times, depends on landscape-specific factors such as local topography, hydrographic characteristics, and degree of soil build-up and preservation.

  13. Vascular inflammatory cells in hypertension

    Directory of Open Access Journals (Sweden)

    David G. Harrison

    2012-05-01

    Full Text Available Hypertension is a common disorder with uncertain etiology. In the last several years, it has become evident that components of both the innate and adaptive immune system play an essential role in hypertension. Macrophages and T cells accumulate in the perivascular fat, the heart and the kidney of hypertensive patients and in animals with experimental hypertension. Various immunosuppressive agents lower blood pressure and prevent end-organ damage. Mice lacking lymphocytes are protected against hypertension, and adoptive transfer of T cells, but not B cells in the animals restores their blood pressure response to stimuli such as angiotensin II or high salt. Recent studies have shown that mice lacking macrophages have blunted hypertension in response to angiotensin II and that genetic deletion of macrophages markedly reduces experimental hypertension. Dendritic cells have also been implicated in this disease. Many hypertensive stimuli have triggering effects on the central nervous system and signals arising from the circumventricular organ seem to promote inflammation. Studies have suggested that central signals activate macrophages and T cells, which home to the kidney and vasculature and release cytokines, including IL-6 and IL-17, which in turn cause renal and vascular dysfunction and lead to blood pressure elevation. These recent discoveries provide a new understanding of hypertension and provide novel therapeutic opportunities for treatment of this serious disease.

  14. Vascular ring complicates accidental button battery ingestion.

    Science.gov (United States)

    Mercer, Ronald W; Schwartz, Matthew C; Stephany, Joshua; Donnelly, Lane F; Franciosi, James P; Epelman, Monica

    2015-01-01

    Button battery ingestion can lead to dangerous complications, including vasculoesophageal fistula formation. The presence of a vascular ring may complicate battery ingestion if the battery lodges at the level of the ring and its important vascular structures. We report a 4-year-old boy with trisomy 21 who was diagnosed with a vascular ring at the time of button battery ingestion and died 9 days after presentation due to massive upper gastrointestinal bleeding from esophageal erosion and vasculoesophageal fistula formation. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Protein-energy malnutrition during early gestation in sheep blunts fetal renal vascular and nephron development and compromises adult renal function.

    Science.gov (United States)

    Lloyd, Louise J; Foster, Thomas; Rhodes, Phillip; Rhind, Stewart M; Gardner, David S

    2012-01-15

    A nutritionally poor maternal diet can reduce nephron endowment and pre-empt premature expression of markers for chronic renal disease in the offspring. A mechanistic pathway from variation in maternal diet through altered fetal renal development to compromised adult kidney structure and function with adult-onset obesity has not been described. We show that maternal protein-energy malnutrition in sheep blunts nephrogenic potential in the 0.44 gestation (65 days gestation, term ∼147 days) fetus by increasing apoptosis and decreasing angiogenesis in the nephrogenic zone, effects that were more marked in male fetuses. As adults, the low-protein-exposed sheep had reduced glomerular number and microvascular rarefaction in their kidneys compensated for, respectively, by glomerular hypertrophy and increased angiogenic support. In this study, the long-term mild anatomical deficits in the kidney would have remained asymptomatic in the lean state, but when superimposed on the broad metabolic challenge that obesity represents then microalbuminuria and blunted bilateral renal function revealed a long-term physiological compromise, that is only predicted to worsen with age. In conclusion, maternal protein-energy malnutrition specifically impacts fetal kidney vascular development and prevents full functionality of the adult kidney being achieved; these residual deficits are predicted to significantly increase the expected incidence of chronic kidney disease in prenatally undernourished individuals especially when coupled with a Western obesogenic environment.

  16. [Experimental study of angiography using vascular interventional robot-2(VIR-2)].

    Science.gov (United States)

    Tian, Zeng-min; Lu, Wang-sheng; Liu, Da; Wang, Da-ming; Guo, Shu-xiang; Xu, Wu-yi; Jia, Bo; Zhao, De-peng; Liu, Bo; Gao, Bao-feng

    2012-06-01

    To verify the feasibility and safety of new vascular interventional robot system used in vascular interventional procedures. Vascular interventional robot type-2 (VIR-2) included master-slave parts of body propulsion system, image navigation systems and force feedback system, the catheter movement could achieve under automatic control and navigation, force feedback was integrated real-time, followed by in vitro pre-test in vascular model and cerebral angiography in dog. Surgeon controlled vascular interventional robot remotely, the catheter was inserted into the intended target, the catheter positioning error and the operation time would be evaluated. In vitro pre-test and animal experiment went well; the catheter can enter any branch of vascular. Catheter positioning error was less than 1 mm. The angiography operation in animal was carried out smoothly without complication; the success rate of the operation was 100% and the entire experiment took 26 and 30 minutes, efficiency was slightly improved compared with the VIR-1, and the time what staff exposed to the DSA machine was 0 minute. The resistance of force sensor can be displayed to the operator to provide a security guarantee for the operation. No surgical complications. VIR-2 is safe and feasible, and can achieve the catheter remote operation and angiography; the master-slave system meets the characteristics of traditional procedure. The three-dimensional image can guide the operation more smoothly; force feedback device provides remote real-time haptic information to provide security for the operation.

  17. Current concepts in the classification, diagnosis and treatment of vascular anomalies

    International Nuclear Information System (INIS)

    Ernemann, Ulrike; Kramer, Ulrich; Miller, Stephan; Bisdas, Sotirios; Rebmann, Hans; Breuninger, Helmut; Zwick, Christine; Hoffmann, Juergen

    2010-01-01

    Patients with extended vascular anomalies may suffer from significant aesthetic and functional impairment and represent a challenge to therapeutic planning, which is best met by an interdisciplinary concept. In agreement with the International Society for the Study of Vascular Anomalies (ISSVA), vascular lesions are classified into haemangiomas as proliferating endothelial tumours on the one hand and congenital vascular malformations on the other. According to the preponderant vascular channels and hemodynamic characteristics, malformations are subdivided into low flow (venous, lymphatic and capillary) lesions and high-flow malformations. Diagnostic imaging should be targeted at the specific structural and functional informations required for treatment planning. The imaging modality of choice to provide these informations is magnetic resonance imaging (MRI) supplemented by magnetic resonance angiography (MRA) with high spatial and temporal resolution. Treatment indications for haemangiomas depend on the proliferative behaviour of the lesion and comprise β-blockers in order to induce involution as well as cryotherapy, laser and open surgery. Interventional radiological procedures have evolved as an essential element in an interdisciplinary treatment plan for vascular malformations and include percutaneous sclerotherapy with ethanol and OK-432 for venous and lymphatic malformations and transarterial embolization for high-flow lesions.

  18. Modelling the development and arrangement of the primary vascular structure in plants.

    Science.gov (United States)

    Cartenì, Fabrizio; Giannino, Francesco; Schweingruber, Fritz Hans; Mazzoleni, Stefano

    2014-09-01

    The process of vascular development in plants results in the formation of a specific array of bundles that run throughout the plant in a characteristic spatial arrangement. Although much is known about the genes involved in the specification of procambium, phloem and xylem, the dynamic processes and interactions that define the development of the radial arrangement of such tissues remain elusive. This study presents a spatially explicit reaction-diffusion model defining a set of logical and functional rules to simulate the differentiation of procambium, phloem and xylem and their spatial patterns, starting from a homogeneous group of undifferentiated cells. Simulation results showed that the model is capable of reproducing most vascular patterns observed in plants, from primitive and simple structures made up of a single strand of vascular bundles (protostele), to more complex and evolved structures, with separated vascular bundles arranged in an ordered pattern within the plant section (e.g. eustele). The results presented demonstrate, as a proof of concept, that a common genetic-molecular machinery can be the basis of different spatial patterns of plant vascular development. Moreover, the model has the potential to become a useful tool to test different hypotheses of genetic and molecular interactions involved in the specification of vascular tissues.

  19. Current concepts in the classification, diagnosis and treatment of vascular anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Ernemann, Ulrike, E-mail: ulrike.ernemann@med.uni-tuebingen.d [Department of Diagnostic and Interventional Neuroradiology, Radiological Clinic, University Hospital Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen (Germany); Kramer, Ulrich; Miller, Stephan [Department of Diagnostic and Interventional Radiology, Radiological Clinic, University Hospital Tuebingen (Germany); Bisdas, Sotirios [Department of Diagnostic and Interventional Neuroradiology, Radiological Clinic, University Hospital Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen (Germany); Rebmann, Hans [Department of Paediatrics, Children' s Hospital, University Hospital Tuebingen (Germany); Breuninger, Helmut [Department of Dermatology, University Hospital Tuebingen (Germany); Zwick, Christine [Department of Hand, Plastic, Reconstructive and Burns Surgery, BG Trauma Clinic Tuebingen, University Hospital Tuebingen (Germany); Hoffmann, Juergen [Department of Oral and Maxillofacial Surgery, University Hospital Tuebingen (Germany)

    2010-07-15

    Patients with extended vascular anomalies may suffer from significant aesthetic and functional impairment and represent a challenge to therapeutic planning, which is best met by an interdisciplinary concept. In agreement with the International Society for the Study of Vascular Anomalies (ISSVA), vascular lesions are classified into haemangiomas as proliferating endothelial tumours on the one hand and congenital vascular malformations on the other. According to the preponderant vascular channels and hemodynamic characteristics, malformations are subdivided into low flow (venous, lymphatic and capillary) lesions and high-flow malformations. Diagnostic imaging should be targeted at the specific structural and functional informations required for treatment planning. The imaging modality of choice to provide these informations is magnetic resonance imaging (MRI) supplemented by magnetic resonance angiography (MRA) with high spatial and temporal resolution. Treatment indications for haemangiomas depend on the proliferative behaviour of the lesion and comprise {beta}-blockers in order to induce involution as well as cryotherapy, laser and open surgery. Interventional radiological procedures have evolved as an essential element in an interdisciplinary treatment plan for vascular malformations and include percutaneous sclerotherapy with ethanol and OK-432 for venous and lymphatic malformations and transarterial embolization for high-flow lesions.

  20. Role of the Vasa Vasorum and Vascular Resident Stem Cells in Atherosclerosis

    Directory of Open Access Journals (Sweden)

    Jun-ichi Kawabe

    2014-01-01

    Full Text Available Atherosclerosis is considered an “inside-out” response, that begins with the dysfunction of intimal endothelial cells and leads to neointimal plaque formation. The adventitia of large blood vessels has been recognized as an active part of the vessel wall that is involved in the process of atherosclerosis. There are characteristic changes in the adventitial vasa vasorum that are associated with the development of atheromatous plaques. However, whether vasa vasorum plays a causative or merely reactive role in the atherosclerotic process is not completely clear. Recent studies report that the vascular wall contains a number of stem/progenitor cells that may contribute to vascular remodeling. Microvessels serve as the vascular niche that maintains the resident stem/progenitor cells of the tissue. Therefore, the vasa vasorum may contribute to vascular remodeling through not only its conventional function as a blood conducting tube, but also its new conceptual function as a stem cell reservoir. This brief review highlights the recent advances contributing to our understanding of the role of the adventitial vasa vasorum in the atherosclerosis and discusses new concept that involves vascular-resident factors, the vasa vasorum and its associated vascular-resident stem cells, in the atherosclerotic process.

  1. [Localized purpura revealing vascular prosthetic graft infection].

    Science.gov (United States)

    Boureau, A S; Lescalie, F; Cassagnau, E; Clairand, R; Connault, J

    2013-07-01

    Prosthetic graft infection after vascular reconstruction is a rare but serious complication. We report a case of infection occurring late after implantation of an iliofemoral prosthetic vascular graft. The Staphylococcus aureus infection was revealed by vascular purpura localized on the right leg 7 years after implantation of a vascular prosthesis. This case illustrates an uncommonly late clinical manifestation presenting as an acute infection 7 years after the primary operation. In this situation, the presentation differs from early infection, which generally occurs within the first four postoperative months. Diagnosis and treatment remain a difficult challenge because prosthetic graft infection is a potentially life-threatening complication. Morbidity and mortality rates are high. Here we detail specific aspects of the clinical and radiological presentation. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  2. Vascular function in health, hypertension, and diabetes

    DEFF Research Database (Denmark)

    Nyberg, Michael Permin; Gliemann, Lasse; Hellsten, Ylva

    2015-01-01

    muscle, which can affect muscle function. Central aspects in the vascular impairments are alterations in the formation of prostacyclin, the bioavailability of NO and an increased formation of vasoconstrictors and reactive oxygen species (ROS). Regular physical activity effectively improves vascular......, the increase in muscle blood flow required for oxygen supply during exercise is achieved through a substantial increase in vasodilators locally formed in the active muscle tissue that overcome the vasoconstrictor signals. Most of the vasodilator signals are mediated via endothelial cells, which lead...... to the formation of vasodilators such as nitric oxide (NO) and prostacyclin. In essential hypertension and type II diabetes, the endothelial function and regulation of vascular tone is impaired with consequent increases in peripheral vascular resistance and inadequate regulation of oxygen supply to the skeletal...

  3. Human genetics of diabetic vascular complications

    Indian Academy of Sciences (India)

    Abstract. Diabetic vascular complications (DVC) affecting several important organ systems of human body such as the ..... cohort with nominal significance, and a recent meta-analysis ..... Whereas it is generally thought that lysine acetylation is.

  4. Incorporating simulation in vascular surgery education.

    Science.gov (United States)

    Bismuth, Jean; Donovan, Michael A; O'Malley, Marcia K; El Sayed, Hosam F; Naoum, Joseph J; Peden, Eric K; Davies, Mark G; Lumsden, Alan B

    2010-10-01

    The traditional apprenticeship model introduced by Halsted of "learning by doing" may just not be valid in the modern practice of vascular surgery. The model is often criticized for being somewhat unstructured because a resident's experience is based on what comes through the "door." In an attempt to promote uniformity of training, multiple national organizations are currently delineating standard curricula for each trainee to govern the knowledge and cases required in a vascular residency. However, the outcomes are anything but uniform. This means that we graduate vascular specialists with a surprisingly wide spectrum of abilities. Use of simulation may benefit trainees in attaining a level of technical expertise that will benefit themselves and their patients. Furthermore, there is likely a need to establish a simulation-based certification process for graduating trainees to further ascertain minimum technical abilities. Copyright © 2010 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

  5. Audit of the Danish national vascular database

    DEFF Research Database (Denmark)

    Levi-Mazloum, Niels Donald; Jensen, L P; Schroeder, T V

    1996-01-01

    The accuracy of data contained in the Danish vascular database was compared with the case notes. A total of 100 case notes were reviewed for 11 pertinent variables in the database. A high error rate ranging from 2 to 34% was found. Also, approximately 10% of patients had never been entered into t...... into the vascular database. Further improvement of the Danish vascular database is necessary for its use as basis for reporting results.......The accuracy of data contained in the Danish vascular database was compared with the case notes. A total of 100 case notes were reviewed for 11 pertinent variables in the database. A high error rate ranging from 2 to 34% was found. Also, approximately 10% of patients had never been entered...

  6. Vascular adaptation to physical inactivity in humans.

    NARCIS (Netherlands)

    Bleeker, M.W.P.

    2006-01-01

    This thesis presents studies on vascular adaptation to physical inactivity and deconditioning. Although it is clear that physical inactivity is an important risk factor for cardiovascular disease, the underlying physiological mechanisms have not yet been elucidated. In contrast to physical

  7. Extracellular Matrix Molecules Facilitating Vascular Biointegration

    Directory of Open Access Journals (Sweden)

    Martin K.C. Ng

    2012-08-01

    Full Text Available All vascular implants, including stents, heart valves and graft materials exhibit suboptimal biocompatibility that significantly reduces their clinical efficacy. A range of biomolecules in the subendothelial space have been shown to play critical roles in local regulation of thrombosis, endothelial growth and smooth muscle cell proliferation, making these attractive candidates for modulation of vascular device biointegration. However, classically used biomaterial coatings, such as fibronectin and laminin, modulate only one of these components; enhancing endothelial cell attachment, but also activating platelets and triggering thrombosis. This review examines a subset of extracellular matrix molecules that have demonstrated multi-faceted vascular compatibility and accordingly are promising candidates to improve the biointegration of vascular biomaterials.

  8. Lipidomics in vascular health: current perspectives.

    Science.gov (United States)

    Kolovou, Genovefa; Kolovou, Vana; Mavrogeni, Sophie

    2015-01-01

    Identifying the mechanisms that convert a healthy vascular wall to an atherosclerotic wall is of major importance since the consequences may lead to a shortened lifespan. Classical risk factors (age, smoking, obesity, diabetes mellitus, hypertension, and dyslipidemia) may result in the progression of atherosclerotic lesions by processes including inflammation and lipid accumulation. Thus, the evaluation of blood lipids and the full lipid complement produced by cells, organisms, or tissues (lipidomics) is an issue of importance. In this review, we shall describe the recent progress in vascular health research using lipidomic advances. We will begin with an overview of vascular wall biology and lipids, followed by a short analysis of lipidomics. Finally, we shall focus on the clinical implications of lipidomics and studies that have examined lipidomic approaches and vascular health.

  9. Lower limb vascular dysfunction in cyclists

    Directory of Open Access Journals (Sweden)

    Thiago Ayala Melo Di Alencar

    2013-06-01

    Full Text Available Sports-related vascular insufficiency affecting the lower limbs is uncommon, and early signs and symptoms can be confused with musculoskeletal injuries. This is also the case among professional cyclists, who are always at the threshold between endurance and excess training. The aim of this review was to analyze the occurrence of vascular disorders in the lower limbs of cyclists and to discuss possible etiologies. Eighty-five texts, including papers and books, published from 1950 to 2012, were used. According to the literature reviewed, some cyclists receive a late diagnosis of vascular dysfunction due to a lack of familiarity of the medical team with this type of dysfunction. Data revealed that a reduced blood flow in the external iliac artery, especially on the left, is much more common than in the femoral and popliteal arteries, and that vascular impairment is responsible for the occurrence of early fatigue and reduced performance in cycling.

  10. Comparative Genomics Yields Insights into Niche Adaptation of Plant Vascular Wilt Pathogens

    NARCIS (Netherlands)

    Klosterman, S.J.; Subbarao, K.V.; Kang, S.; Veronese, P.; Gold, S.E.; Thomma, B.P.H.J.; Chen, Z.J.; Henrissat, B.; Lee, Y.H.; Park, J.; Garcia-Pedrajas, M.D.; Barbara, D.J.; Anchieta, A.; Jonge, de R.; Santhanam, P.; Maruthachalam, K.; Atallah, Z.; Amyotte, S.G.; Paz, Z.; Inderbitzin, P.; Hayes, R.J.; Heiman, D.I.; Young, S.; Zeng, Q.; Engels, R.; Galagan, J.; Cuomo, C.; Dobinson, K.F.; Ma, L.J.

    2011-01-01

    The vascular wilt fungi Verticillium dahliae and V. albo-atrum infect over 200 plant species, causing billions of dollars in annual crop losses. The characteristic wilt symptoms are a result of colonization and proliferation of the pathogens in the xylem vessels, which undergo fluctuations in

  11. Transient monocular blindness and the risk of vascular complications according to subtype : a prospective cohort study

    NARCIS (Netherlands)

    Volkers, Eline J; Donders, Richard C J M; Koudstaal, Peter J; van Gijn, Jan; Algra, Ale; Jaap Kappelle, L

    Patients with transient monocular blindness (TMB) can present with many different symptoms, and diagnosis is usually based on the history alone. In this study, we assessed the risk of vascular complications according to different characteristics of TMB. We prospectively studied 341 consecutive

  12. Transient monocular blindness and the risk of vascular complications according to subtype: a prospective cohort study

    NARCIS (Netherlands)

    Volkers, E.J. (Eline J.); R. Donders (Rogier); P.J. Koudstaal (Peter Jan); van Gijn, J. (Jan); A. Algra (Ale); L. Jaap Kappelle

    2016-01-01

    textabstractPatients with transient monocular blindness (TMB) can present with many different symptoms, and diagnosis is usually based on the history alone. In this study, we assessed the risk of vascular complications according to different characteristics of TMB. We prospectively studied 341

  13. Vascular channels in metacarpophalangeal joints : a comparative histologic and high-resolution imaging study

    NARCIS (Netherlands)

    Scharmga, A.; Keller, K.K.; Peters, M.; van Tubergen, A.; van den Bergh, J.P.W.; van Rietbergen, B.; Weijers, R.; Loeffen, D.; Hauge, E.M.; Geusens, P.P.M.M.

    2017-01-01

    We evaluated whether cortical interruptions classified as vascular channel (VC) on high-resolution peripheral quantitative computed tomography (HR-pQCT) could be confirmed by histology. We subsequently evaluated the image characteristics of histologically identified VCs on matched single and

  14. Laser-assisted vascular anastomosis

    Science.gov (United States)

    Kao, Race L.; Tsao-Wu, George; Magovern, George J.

    1990-06-01

    The milliwatt CO2 laser and a thermal activated binding compound (20% serum albumin) were used for microvascular anastomoses. Under general anesthesia, the femoral arteries (0.7 to 1.0 mm diameter) of 6 rats were isolated. After the left femoral artery in each rat was clamped and transected, the vessel was held together with 3 equidistant 10-0 Xomed sutures. The cut edges were coated 3 to 4 times with the albumin solution and sealed with the CO2 laser (power density = 120 W/cm2). The binding compound solidified to a translucent tensile substance which supported the anastomosis until self healing and repair were achieved. The right femoral artery was used as sham operated control. Complete hemostasis and patency were observed in every case immediately and at 1, 3, and 6 months following surgery. The binding compound absorbed most of the laser energy thus minimizing thermal injury to the underlying tissue. Mongrel dogs weighing 28 to 33 kg were anesthetized and prepared for sterile surgical procedures. In 5 dogs, the femoral and jugular veins were exposed, transected, and anastomosed using a CO2 laser (Sharplan 1040) with the binding compound. In another 12 dogs, cephalic veins were isolated and used for aortocoronary artery bypass procedures. The Sharplan 1040 CO2 laser and 20% albumin solution were utilized to complete the coronary anastomoses in 6 dogs, and 6 dogs were used as controls by suturing the vessels. Again, hemostasis, patency, and minimal tissue damage were observed immediately and 6 weeks after the procedures. Improved surgical results, reduced operating time, minimized tissue damage, and enhanced anastomotic integrity are the advantages of laser assisted vascular anastomosis with a thermal activated binding compound.

  15. Vascular access choice in incident hemodialysis patients: a decision analysis.

    Science.gov (United States)

    Drew, David A; Lok, Charmaine E; Cohen, Joshua T; Wagner, Martin; Tangri, Navdeep; Weiner, Daniel E

    2015-01-01

    Hemodialysis vascular access recommendations promote arteriovenous (AV) fistulas first; however, it may not be the best approach for all hemodialysis patients, because likelihood of successful fistula placement, procedure-related and subsequent costs, and patient survival modify the optimal access choice. We performed a decision analysis evaluating AV fistula, AV graft, and central venous catheter (CVC) strategies for patients initiating hemodialysis with a CVC, a scenario occurring in over 70% of United States dialysis patients. A decision tree model was constructed to reflect progression from hemodialysis initiation. Patients were classified into one of three vascular access choices: maintain CVC, attempt fistula, or attempt graft. We explicitly modeled probabilities of primary and secondary patency for each access type, with success modified by age, sex, and diabetes. Access-specific mortality was incorporated using preexisting cohort data, including terms for age, sex, and diabetes. Costs were ascertained from the 2010 USRDS report and Medicare for procedure costs. An AV fistula attempt strategy was found to be superior to AV grafts and CVCs in regard to mortality and cost for the majority of patient characteristic combinations, especially younger men without diabetes. Women with diabetes and elderly men with diabetes had similar outcomes, regardless of access type. Overall, the advantages of an AV fistula attempt strategy lessened considerably among older patients, particularly women with diabetes, reflecting the effect of lower AV fistula success rates and lower life expectancy. These results suggest that vascular access-related outcomes may be optimized by considering individual patient characteristics. Copyright © 2015 by the American Society of Nephrology.

  16. Natural history of splenic vascular abnormalities after blunt injury: A Western Trauma Association multicenter trial.

    Science.gov (United States)

    Zarzaur, Ben L; Dunn, Julie A; Leininger, Brian; Lauerman, Margaret; Shanmuganathan, Kathirkamanthan; Kaups, Krista; Zamary, Kirellos; Hartwell, Jennifer L; Bhakta, Ankur; Myers, John; Gordy, Stephanie; Todd, Samuel R; Claridge, Jeffrey A; Teicher, Erik; Sperry, Jason; Privette, Alicia; Allawi, Ahmed; Burlew, Clay Cothren; Maung, Adrian A; Davis, Kimberly A; Cogbill, Thomas; Bonne, Stephanie; Livingston, David H; Coimbra, Raul; Kozar, Rosemary A

    2017-12-01

    Following blunt splenic injury, there is conflicting evidence regarding the natural history and appropriate management of patients with vascular injuries of the spleen such as pseudoaneurysms or blushes. The purpose of this study was to describe the current management and outcomes of patients with pseudoaneurysm or blush. Data were collected on adult (aged ≥18 years) patients with blunt splenic injury and a splenic vascular injury from 17 trauma centers. Demographic, physiologic, radiographic, and injury characteristics were gathered. Management and outcomes were collected. Univariate and multivariable analyses were used to determine factors associated with splenectomy. Two hundred patients with a vascular abnormality on computed tomography scan were enrolled. Of those, 14.5% were managed with early splenectomy. Of the remaining patients, 59% underwent angiography and embolization (ANGIO), and 26.5% were observed. Of those who underwent ANGIO, 5.9% had a repeat ANGIO, and 6.8% had splenectomy. Of those observed, 9.4% had a delayed ANGIO, and 7.6% underwent splenectomy. There were no statistically significant differences between those observed and those who underwent ANGIO. There were 111 computed tomography scans with splenic vascular injuries available for review by an expert trauma radiologist. The concordance between the original classification of the type of vascular abnormality and the expert radiologist's interpretation was 56.3%. Based on expert review, the presence of an actively bleeding vascular injury was associated with a 40.9% risk of splenectomy. This was significantly higher than those with a nonbleeding vascular injury. In this series, the vast majority of patients are managed with ANGIO and usually embolization, whereas splenectomy remains a rare event. However, patients with a bleeding vascular injury of the spleen are at high risk of nonoperative failure, no matter the strategy used for management. This group may warrant closer observation or

  17. Biomimicry, vascular restenosis and coronary stents.

    Science.gov (United States)

    Schwartz, R S; van der Giessen, W J; Holmes, D R

    1998-01-01

    Biomimicry is in its earliest stages and is being considered in the realm of tissue engineering. If arterial implants are to limit neointimal thickening, purely passive structures cannot succeed. Bioactivity must be present, either by pharmacologic intervention or by fabricating a 'living stent' that contains active cellular material. As tissue engineering evolves, useful solutions will emerge from applying this knowledge directly to vascular biologic problems resulting from angioplasty, stenting, and vascular prosthesis research.

  18. The current role of vascular stents.

    Science.gov (United States)

    Busquet, J

    1993-09-01

    The limitations of percutaneous balloon angioplasty have favoured the development and the use of vascular endoprostheses or stents. These thin-walled metal devices maintain after expansion, an optimal and constant diameter for the vascular lumen. Restenosis, dissection, abrupt closure, residual stenosis or re-opened total occlusion represent appropriate indications for stenting. A large experience with non-coronary application of stents is currently available in iliac, femoro-popliteal and renal arteries, aorta, large veins.

  19. Vascular colitis: a report of two cases

    Energy Technology Data Exchange (ETDEWEB)

    Park, Chan Il; Han, Chang Yul; Han, Man Chung; Choo, Dong Woon [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1973-04-15

    The authors report two cases of vascular colitis in Korean with a review of literature. Case I, 20 years old male had severe abdominal pain and bloody diarrhea. Case II was 57 years old male and complained severe abdominal pain. Barium enema colon study on each cases disclosed typical thumbprinting appearance of involved segment. Predisposing factor in case I appeared to be anaphylactoid purpura, and in case II distal obstruction due to adenocarcinoma. The mechanism of vascular was briefly discussed.

  20. Robotic vascular resections during Whipple procedure.

    Science.gov (United States)

    Allan, Bassan J; Novak, Stephanie M; Hogg, Melissa E; Zeh, Herbert J

    2018-01-01

    Indications for resection of pancreatic cancers have evolved to include selected patients with involvement of peri-pancreatic vascular structures. Open Whipple procedures have been the standard approach for patients requiring reconstruction of the portal vein (PV) or superior mesenteric vein (SMV). Recently, high-volume centers are performing minimally invasive Whipple procedures with portovenous resections. Our institution has performed seventy robotic Whipple procedures with concomitant vascular resections. This report outlines our technique.

  1. Effects of ouabain on vascular reactivity

    Directory of Open Access Journals (Sweden)

    Vassallo D.V.

    1997-04-01

    Full Text Available Ouabain is an endogenous substance occurring in the plasma in the nanomolar range, that has been proposed to increase vascular resistance and induce hypertension. This substance acts on the a-subunit of Na+,K+-ATPase inhibiting the Na+-pump activity. In the vascular smooth muscle this effect leads to intracellular Na+ accumulation that reduces the activity of the Na+/Ca2+ exchanger and to an increased vascular tone. It was also suggested that circulating ouabain, even in the nanomolar range, sensitizes the vascular smooth muscle to vasopressor substances. We tested the latter hypothesis by studying the effects of ouabain in the micromolar and nanomolar range on phenylephrine (PE-evoked pressor responses. The experiments were performed in normotensive and hypertensive rats in vivo, under anesthesia, and in perfused rat tail vascular beds. The results showed that ouabain pretreatment increased the vasopressor responses to PE in vitro and in vivo. This sensitization after ouabain treatment was also observed in hypertensive animals which presented an enhanced vasopressor response to PE in comparison to normotensive animals. It is suggested that ouabain at nanomolar concentrations can sensitize vascular smooth muscle to vasopressor stimuli possibly contributing to increased tone in hypertension

  2. 3D bioprinting for vascularized tissue fabrication

    Science.gov (United States)

    Richards, Dylan; Jia, Jia; Yost, Michael; Markwald, Roger; Mei, Ying

    2016-01-01

    3D bioprinting holds remarkable promise for rapid fabrication of 3D tissue engineering constructs. Given its scalability, reproducibility, and precise multi-dimensional control that traditional fabrication methods do not provide, 3D bioprinting provides a powerful means to address one of the major challenges in tissue engineering: vascularization. Moderate success of current tissue engineering strategies have been attributed to the current inability to fabricate thick tissue engineering constructs that contain endogenous, engineered vasculature or nutrient channels that can integrate with the host tissue. Successful fabrication of a vascularized tissue construct requires synergy between high throughput, high-resolution bioprinting of larger perfusable channels and instructive bioink that promotes angiogenic sprouting and neovascularization. This review aims to cover the recent progress in the field of 3D bioprinting of vascularized tissues. It will cover the methods of bioprinting vascularized constructs, bioink for vascularization, and perspectives on recent innovations in 3D printing and biomaterials for the next generation of 3D bioprinting for vascularized tissue fabrication. PMID:27230253

  3. Vascular retraction driven by matrix softening

    Science.gov (United States)

    Valentine, Megan

    We recently discovered we can directly apply physical forces and monitor the downstream responses in a living organism in real time through manipulation of the blood vessels of a marine organism called, Botryllus schlosseri. The extracellular matrix (ECM) plays a key role in regulating vascular growth and homeostasis in Botryllus,a basal chordate which has a large, transparent extracorporeal vascular network that can encompass areas >100 cm2. We have determined that lysyl oxidase 1 (LOX1), which is responsible for cross-linking collagen, is expressed in all vascular cells and is critically important for vascular maintenance. Inhibition of LOX1 activity in vivo by the addition of a specific inhibitor, ß-aminopropionitrile (BAPN), caused a rapid, global regression of the entire vascular bed, with some vessels regressing >10 mm within 16 hrs. In this talk, I will discuss the molecular and cellular origins of this systemic remodeling event, which hinges upon the ability of the vascular cells to sense and respond to mechanical signals, while introducing this exciting new model system for studies of biological physics and mechanobiology. Collaborators: Anthony DeTomaso, Delany Rodriguez, Aimal Khankhel (UCSB).

  4. [Vascular aging, arterial hypertension and physical activity].

    Science.gov (United States)

    Schmidt-Trucksäss, A; Weisser, B

    2011-11-01

    The present review delineates the significance of intima-media-thickness, arterial stiffness and endothelial function for vascular aging. There is profound evidence for an increase in intima-media-thickness and vascular stiffness not only during healthy aging but induced also by cardiovascular risk factors. There is a central role of arterial hypertension for this progression in both structural factors. In addition, both parameters are strongly associated with cardiovascular risk. Endothelial function measured as postischemic flow-mediated vasodilatation is a functional parameter which is decreased both in healthy aging and by cardiovascular risk factors. Physical activity modifies the influence of aging and risk factors on endothelial function. A positive influence of endurance exercise on vascular stiffness and endothelial function has been demonstrated in numerous studies. In long-term studies, regular physical activity has been shown to reduce the progression of intima-media-thickness. Thus, arterial hypertension accelerates vascular aging, while physical activity has a positive influence on a variety of vascular parameters associated with vascular aging. © Georg Thieme Verlag KG Stuttgart · New York.

  5. Vascular Adventitia Calcification and Its Underlying Mechanism.

    Directory of Open Access Journals (Sweden)

    Na Li

    Full Text Available Previous research on vascular calcification has mainly focused on the vascular intima and media. However, we show here that vascular calcification may also occur in the adventitia. The purpose of this work is to help elucidate the pathogenic mechanisms underlying vascular calcification. The calcified lesions were examined by Von Kossa staining in ApoE-/- mice which were fed high fat diets (HFD for 48 weeks and human subjects aged 60 years and older that had died of coronary heart disease, heart failure or acute renal failure. Explant cultured fibroblasts and smooth muscle cells (SMCswere obtained from rat adventitia and media, respectively. After calcification induction, cells were collected for Alizarin Red S staining. Calcified lesions were observed in the aorta adventitia and coronary artery adventitia of ApoE-/-mice, as well as in the aorta adventitia of human subjects examined. Explant culture of fibroblasts, the primary cell type comprising the adventitia, was successfully induced for calcification after incubation with TGF-β1 (20 ng/ml + mineralization media for 4 days, and the phenotype conversion vascular adventitia fibroblasts into myofibroblasts was identified. Culture of SMCs, which comprise only a small percentage of all cells in the adventitia, in calcifying medium for 14 days resulted in significant calcification.Vascular calcification can occur in the adventitia. Adventitia calcification may arise from the fibroblasts which were transformed into myofibroblasts or smooth muscle cells.

  6. Patterns of peripheral vascular diseases at Muhimbili National hospital

    African Journals Online (AJOL)

    diseases) and HIV- vasculitis. A total of 97 patients (63%) were surgically treated. Conclusion: Shortage of vascular surgeons and facilities in our. Country needs to be sorted out to save life to these patients with vascular disorders. Key Words: Peripheral Vascular Diseases, and Shortage of Vascular Services in Tanzania.

  7. Lung irradiation induces pulmonary vascular remodelling resembling pulmonary arterial hypertension

    NARCIS (Netherlands)

    Ghobadi, G.; Bartelds, B.; van der Veen, S. J.; Dickinson, M. G.; Brandenburg, S.; Berger, R. M. F.; Langendijk, J. A.; Coppes, R. P.; van Luijk, P.

    Background Pulmonary arterial hypertension (PAH) is a commonly fatal pulmonary vascular disease that is often diagnosed late and is characterised by a progressive rise in pulmonary vascular resistance resulting from typical vascular remodelling. Recent data suggest that vascular damage plays an

  8. Vascular associated gene variants in patients with preeclampsia

    DEFF Research Database (Denmark)

    Lykke, Jacob A; Bare, Lance A; Olsen, Jørn

    2012-01-01

    Preeclampsia has been linked to subsequent vascular disease with many shared predisposing factors. We investigated the association between severe preeclampsia, and its subtypes, and specific vascular-related polymorphisms.......Preeclampsia has been linked to subsequent vascular disease with many shared predisposing factors. We investigated the association between severe preeclampsia, and its subtypes, and specific vascular-related polymorphisms....

  9. Sirtuins, Cell Senescence, and Vascular Aging.

    Science.gov (United States)

    Kida, Yujiro; Goligorsky, Michael S

    2016-05-01

    The sirtuins (SIRTs) constitute a class of proteins with nicotinamide adenine dinucleotide-dependent deacetylase or adenosine diphosphate-ribosyltransferase activity. Seven SIRT family members have been identified in mammals, from SIRT1, the best studied for its role in vascular aging, to SIRT7. SIRT1 and SIRT2 are localized in the nucleus and cytoplasm. SIRT3, SIRT4, and SIRT5 are mitochondrial, and SIRT6 and SIRT7 are nuclear. Extensive studies have clearly revealed that SIRT proteins regulate diverse cell functions and responses to stressors. Vascular aging involves the aging process (senescence) of endothelial and vascular smooth muscle cells. Two types of cell senescence have been identified: (1) replicative senescence with telomere attrition; and (2) stress-induced premature senescence without telomere involvement. Both types of senescence induce vascular cell growth arrest and loss of vascular homeostasis, and contribute to the initiation and progression of cardiovascular diseases. Previous mechanistic studies have revealed in detail that SIRT1, SIRT3, and SIRT6 show protective functions against vascular aging, and definite vascular function of other SIRTs is under investigation. Thus, direct SIRT modulation and nicotinamide adenine dinucleotide stimulation of SIRT are promising candidates for cardiovascular disease therapy. A small number of pilot studies have been conducted to assess SIRT modulation in humans. These clinical studies have not yet provided convincing evidence that SIRT proteins alleviate morbidity and mortality in patients with cardiovascular diseases. The outcomes of multiple ongoing clinical trials are awaited to define the efficacy of SIRT modulators and SIRT activators in cardiovascular diseases, along with the potential adverse effects of chronic SIRT modulation. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  10. Progenitor cells in pulmonary vascular remodeling

    Science.gov (United States)

    Yeager, Michael E.; Frid, Maria G.; Stenmark, Kurt R.

    2011-01-01

    Pulmonary hypertension is characterized by cellular and structural changes in the walls of pulmonary arteries. Intimal thickening and fibrosis, medial hypertrophy and fibroproliferative changes in the adventitia are commonly observed, as is the extension of smooth muscle into the previously non-muscularized vessels. A majority of these changes are associated with the enhanced presence of α-SM-actin+ cells and inflammatory cells. Atypical abundances of functionally distinct endothelial cells, particularly in the intima (plexiform lesions), and also in the perivascular regions, are also described. At present, neither the origin(s) of these cells nor the molecular mechanisms responsible for their accumulation, in any of the three compartments of the vessel wall, have been fully elucidated. The possibility that they arise from either resident vascular progenitors or bone marrow–derived progenitor cells is now well established. Resident vascular progenitor cells have been demonstrated to exist within the vessel wall, and in response to certain stimuli, to expand and express myofibroblastic, endothelial or even hematopoietic markers. Bone marrow–derived or circulating progenitor cells have also been shown to be recruited to sites of vascular injury and to assume both endothelial and SM-like phenotypes. Here, we review the data supporting the contributory role of vascular progenitors (including endothelial progenitor cells, smooth muscle progenitor cells, pericytes, and fibrocytes) in vascular remodeling. A more complete understanding of the processes by which progenitor cells modulate pulmonary vascular remodeling will undoubtedly herald a renaissance of therapies extending beyond the control of vascular tonicity and reduction of pulmonary artery pressure. PMID:22034593

  11. Congenital vascular malformations in scintigraphic evaluation

    International Nuclear Information System (INIS)

    Pilecki, Stanisław; Gierach, Marcin; Gierach, Joanna; Świętaszczyk, Cyprian; Junik, Roman; Lasek, Władysław

    2014-01-01

    Congenital vascular malformations are tumour-like, non-neoplastic lesions caused by disorders of vascular tissue morphogenesis. They are characterised by a normal cell replacement cycle throughout all growth phases and do not undergo spontaneous involution. Here we present a scintigraphic image of familial congenital vascular malformations in two sisters. A 17-years-old young woman with a history of multiple hospitalisations for foci of vascular anomalies appearing progressively in the upper and lower right limbs, chest wall and spleen. A Parkes Weber syndrome was diagnosed based on the clinical picture. Due to the occurrence of new foci of malformations, a whole-body scintigraphic examination was performed. A 12-years-old girl reported a lump in the right lower limb present for approximately 2 years, which was clinically identified as a vascular lesion in the area of calcaneus and talus. Phleboscintigraphy visualized normal radiomarker outflow from the feet via the deep venous system, also observed in the superficial venous system once the tourniquets were released. In static and whole-body examinations vascular malformations were visualised in the area of the medial cuneiform, navicular and talus bones of the left foot, as well as in the projection of right calcaneus and above the right talocrural joint. People with undiagnosed disorders related to the presence of vascular malformations should undergo periodic follow-up to identify lesions that may be the cause of potentially serious complications and to assess the results of treatment. Presented scintigraphic methods may be used for both diagnosing and monitoring of disease progression

  12. Gene transfer therapy in vascular diseases.

    Science.gov (United States)

    McKay, M J; Gaballa, M A

    2001-01-01

    Somatic gene therapy of vascular diseases is a promising new field in modern medicine. Recent advancements in gene transfer technology have greatly evolved our understanding of the pathophysiologic role of candidate disease genes. With this knowledge, the expression of selective gene products provides the means to test the therapeutic use of gene therapy in a multitude of medical conditions. In addition, with the completion of genome sequencing programs, gene transfer can be used also to study the biologic function of novel genes in vivo. Novel genes are delivered to targeted tissue via several different vehicles. These vectors include adenoviruses, retroviruses, plasmids, plasmid/liposomes, and oligonucleotides. However, each one of these vectors has inherent limitations. Further investigations into developing delivery systems that not only allow for efficient, targeted gene transfer, but also are stable and nonimmunogenic, will optimize the clinical application of gene therapy in vascular diseases. This review further discusses the available mode of gene delivery and examines six major areas in vascular gene therapy, namely prevention of restenosis, thrombosis, hypertension, atherosclerosis, peripheral vascular disease in congestive heart failure, and ischemia. Although we highlight some of the recent advances in the use of gene therapy in treating vascular disease discovered primarily during the past two years, many excellent studies published during that period are not included in this review due to space limitations. The following is a selective review of practical uses of gene transfer therapy in vascular diseases. This review primarily covers work performed in the last 2 years. For earlier work, the reader may refer to several excellent review articles. For instance, Belalcazer et al. (6) reviewed general aspects of somatic gene therapy and the different vehicles used for the delivery of therapeutic genes. Gene therapy in restenosis and stimulation of

  13. Nitric oxide is a key molecule in migraine and other vascular headaches

    DEFF Research Database (Denmark)

    Olesen, J; Thomsen, L L; Iversen, Helle Klingenberg

    1994-01-01

    Nitric oxide (NO) may play a key role in migraine and other vascular headaches since glyceryl trinitrate (a donor of NO) and histamine (which probably activates endothelial NO formation) both cause a pulsating dose-dependent headache with several migrainous characteristics. At relatively high doses...... Olesen, Lars Thomsen and Helle Iversen suggest that migraine may be caused by increased amounts and/or affinity of an enzyme in the NO-triggered cascade of reactions. NO may also be involved in the pathogenesis of other vascular headaches....

  14. A case of vascular Ehlers-Danlos Syndrome with a cardiomyopathy and multi-system involvement.

    Science.gov (United States)

    Lan, Nick Si Rui; Fietz, Michael; Pachter, Nicholas; Paul, Vincent; Playford, David

    Ehlers-Danlos Syndrome comprises a heterogeneous group of heritable connective tissue disorders resulting from various gene mutations. We present an unusual case of vascular Ehlers-Danlos Syndrome with distinctive physical characteristics and a cardiomyopathy with features suggesting isolated left ventricular non-compaction. The cardiac features represent the first report of a cardiomyopathy associated with a mutation in the COL3A1 gene. This case also illustrates the multi-system nature of Ehlers-Danlos Syndrome and the complexity of managing patients with the vascular subtype. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Adiposity, adipocytokines & microvesicles in the etiology of vascular disease

    OpenAIRE

    Kanhai, D.A.N.I.S.

    2013-01-01

    Vascular disease, in this thesis the terms vascular and cardiovascular are used interchangeably, is the number 1 cause of death worldwide. In 2008, 30% of all mortality had a vascular origin. Vascular mortality rates after a first manifestation of vascular disease are decreasing in Western society, which is attributable to better disease awareness, better preventive strategies and better healthcare systems. As mortality rates are decreasing, the number of patients surviving their first vascul...

  16. Risk stratification for the development of respiratory adverse events following vascular surgery using the Society of Vascular Surgery's Vascular Quality Initiative.

    Science.gov (United States)

    Genovese, Elizabeth A; Fish, Larry; Chaer, Rabih A; Makaroun, Michel S; Baril, Donald T

    2017-02-01

    Postoperative respiratory adverse events (RAEs) are associated with high rates of morbidity and mortality in general surgery, however, little is known about these complications in the vascular surgery population, a frail subset with multiple comorbidities. The objective of this study was to describe the contemporary incidence of RAEs in vascular surgery patients, the risk factors for this complication, and the overall impact of RAEs on patient outcomes. The Vascular Quality Initiative was queried (2003-2014) for patients who underwent endovascular abdominal aortic repair, open abdominal aortic aneurysm repair, thoracic endovascular aortic repair, suprainguinal bypass, or infrainguinal bypass. A mixed-effects logistic regression model determined the independent risk factors for RAEs. Using a random 85% of the cohort, a risk prediction score for RAEs was created, and the score was validated using the remaining 15% of the cohort, comparing the predicted to the actual incidence of RAE and determining the area under the receiver operating characteristic curve. The independent risk of in-hospital mortality and discharge to a nursing facility associated with RAEs was determined using a mixed-effects logistic regression to control for baseline patient characteristics, operative variables, and other postoperative adverse events. The cohort consisted of 52,562 patients, with a 5.4% incidence of RAEs. The highest rates of RAEs were seen in current smokers (6.1%), recent acute myocardial infarction (10.1%), symptomatic congestive heart failure (9.9%), chronic obstructive pulmonary disease requiring oxygen therapy (11.0%), urgent and emergent procedures (6.4% and 25.9%, respectively), open abdominal aortic aneurysm repairs (17.6%), in situ suprainguinal bypasses (9.68%), and thoracic endovascular aortic repairs (9.6%). The variables included in the risk prediction score were age, body mass index, smoking status, congestive heart failure severity, chronic obstructive pulmonary

  17. Preparation and features of polycaprolactone vascular grafts with the incorporated vascular endothelial growth factor

    Energy Technology Data Exchange (ETDEWEB)

    Sevostyanova, V. V., E-mail: sevostyanova.victoria@gmail.com; Khodyrevskaya, Y. I.; Glushkova, T. V.; Antonova, L. V.; Kudryavtseva, Y. A.; Barbarash, O. L.; Barbarash, L. S. [Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo (Russian Federation)

    2015-10-27

    The development of tissue-engineered small-diameter vascular grafts is an urgent issue in cardiovascular surgery. In this study, we assessed how the incorporation of the vascular endothelial growth factor (VEGF) affects morphological and mechanical properties of polycaprolactone (PCL) vascular grafts along with its release kinetics. Vascular grafts were prepared using two-phase electrospinning. In pursuing our aims, we performed scanning electron microscopy, mechanical testing, and enzyme-linked immunosorbent assay. Our results demonstrated the preservation of a highly porous structure and improvement of PCL/VEGF scaffold mechanical properties as compared to PCL grafts. A prolonged VEGF release testifies the use of this construct as a scaffold for tissue-engineered vascular grafts.

  18. Effects of PPARγ ligands on vascular tone.

    Science.gov (United States)

    Salomone, Salvatore; Drago, Filippo

    2012-06-01

    Peroxisome Proliferator-Activated Receptor γ (PPARγ), originally described as a transcription factor for genes of carbohydrate and lipid metabolism, has been more recently studied in the context of cardiovascular pathophysiology. Here, we review the available data on PPARγ ligands as modulator of vascular tone. PPARγ ligands include: thiazolidinediones (used in the treatment of type 2 diabetes mellitus), glitazars (bind and activate both PPARγ and PPARα), and other experimental drugs (still in development) that exploit the chemistry of thiazolidinediones as a scaffold for PPARγ-independent pharmacological properties. In this review, we examine both short (mostly from in vitro data)- and long (mostly from in vivo data)-term effects of PPARγ ligands that extend from PPARγ-independent vascular effects to PPARγ-dependent gene expression. Because endothelium is a master regulator of vascular tone, we have attempted to differentiate between endothelium-dependent and endothelium-independent effects of PPARγ ligands. Based on available data, we conclude that PPARγ ligands appear to influence vascular tone in different experimental paradigms, most often in terms of vasodilatation (potentially increasing blood flow to some tissues). These effects on vascular tone, although potentially beneficial, must be weighed against specific cardiovascular warnings that may apply to some drugs, such as rosiglitazone.

  19. Insulin resistance: vascular function and exercise

    Directory of Open Access Journals (Sweden)

    Moon-Hyon Hwang

    2016-09-01

    Full Text Available Insulin resistance associated with metabolic syndrome and Type 2 diabetes mellitus is an epidemic metabolic disorder, which increases the risk of cardiovascular complications. Impaired vascular endothelial function is an early marker for atherosclerosis, which causes cardiovascular complications. Both experimental and clinical studies indicate that endothelial dysfunction in vasculatures occurs with insulin resistance. The associated physiological mechanisms are not fully appreciated yet, however, it seems that augmented oxidative stress, a physiological imbalance between oxidants and antioxidants, in vascular cells is a possible mechanism involved in various vascular beds with insulin resistance and hyperglycemia. Regardless of the inclusion of resistance exercise, aerobic exercise seems to be beneficial for vascular endothelial function in both large conduit and small resistance vessels in both clinical and experimental studies with insulin resistance. In clinical cases, aerobic exercise over 8 weeks with higher intensity seems more beneficial than the cases with shorter duration and lower intensity. However, more studies are needed in the future to elucidate the physiological mechanisms by which vascular endothelial function is impaired in insulin resistance and improved with aerobic exercise.

  20. Vascular trauma: selected historical reflections from the

    Directory of Open Access Journals (Sweden)

    Rich Norman M

    2011-04-01

    Full Text Available 【Abstract】In the spirit of international exchanges of knowledge with colleagues from all over the world, who are interested in the care and treatment of vascular trauma, we offer selected historical reflections from the western world on vascular trauma. Whereas there are a number of key individuals and a variety of events that are important to us in our writing, we know essentially nothing about what is written by other cultures and, particularly, the Chinese. It is well recognized around the world that Chinese surgeons are among the first to be highly successful in re-plantation of severed extremities, repairing both injured arteries and veins. Also, we recognize that there are contributions in other parts of the world, which are not well known to us collectively. Contributions from the Arabic speaking part of the world come to mind because there is periodic brief reference. We offer our perspective hoping that there will be one or more Chinese surgeons who will offer us the benefit of sharing their perspective on important historical contributions to the managing of vascular trauma outside of the western world, and, particularly, the English speaking literature. Once again, we encourage our colleagues in the Arabic speaking world to provide us with their perspective of the development and management of vascular trauma. Key words: Vascular system injuries; History; Western world; International educational exchange

  1. Arteriographic evaluation, in the perispheric vascular trauma

    International Nuclear Information System (INIS)

    Patino, Jairo Hernando; Granados, Ana Maria; Lopera B, Jorge; Prada W, Angela Maria

    1993-01-01

    136 patients were angiographically studied under the suspicion of perispheric vascular lesion submitted to the radiology department of the San Vicente de Paul University Hospital (H.U.S.VP.) Medellin Colombia. The majority of the patients were young with wounds caused by gunshots (79.4%). the must frequent angiographic indication was the proximity of the wound to a vascular path (44.5%). 63% of the patients with angiography indicative of abnormality needed surgery from which 21% were because of the proximity of the wound to a vascular path and 76% because of the mayor findings when admitted to the hospital. the possible complications as a result of the angiographic procedure were revised only find inc two mayor reactions to the contrast media. there were no late complications. Angiography is highlighting sensitive (100%) specific (98.5%) and secure in the evaluation of patients with perispheric vascular trauma. Due to the high number of false negatives when the physical examination is performed, every patient with a wound near a vascular path must be evaluated angiographically

  2. Endothelial dysfunction in metabolic and vascular disorders.

    Science.gov (United States)

    Polovina, Marija M; Potpara, Tatjana S

    2014-03-01

    Vascular endothelium has important regulatory functions in the cardiovascular system and a pivotal role in the maintenance of vascular health and metabolic homeostasis. It has long been recognized that endothelial dysfunction participates in the pathogenesis of atherosclerosis from early, preclinical lesions to advanced, thrombotic complications. In addition, endothelial dysfunction has been recently implicated in the development of insulin resistance and type 2 diabetes mellitus (T2DM). Considering that states of insulin resistance (eg, metabolic syndrome, impaired fasting glucose, impaired glucose tolerance, and T2DM) represent the most prevalent metabolic disorders and risk factors for atherosclerosis, it is of considerable scientific and clinical interest that both metabolic and vascular disorders have endothelial dysfunction as a common background. Importantly, endothelial dysfunction has been associated with adverse outcomes in patients with established cardiovascular disease, and a growing body of evidence indicates that endothelial dysfunction also imparts adverse prognosis in states of insulin resistance. In this review, we discuss the association of insulin resistance and T2DM with endothelial dysfunction and vascular disease, with a focus on the underlying mechanisms and prognostic implications of the endothelial dysfunction in metabolic and vascular disorders. We also address current therapeutic strategies for the improvement of endothelial dysfunction.

  3. Nanomedicine approaches in vascular disease: a review.

    Science.gov (United States)

    Gupta, Anirban Sen

    2011-12-01

    Nanomedicine approaches have revolutionized the treatment of cancer and vascular diseases, where the limitations of rapid nonspecific clearance, poor biodistribution and harmful side effects associated with direct systemic drug administration can be overcome by packaging the agents within sterically stabilized, long-circulating nanovehicles that can be further surface-modified with ligands to actively target cellular/molecular components of the disease. With significant advancements in genetics, proteomics, cellular and molecular biology and biomaterials engineering, the nanomedicine strategies have become progressively refined regarding the modulation of surface and bulk chemistry of the nanovehicles, control of drug release kinetics, manipulation of nanoconstruct geometry and integration of multiple functionalities on single nanoplatforms. The current review aims to capture the various nanomedicine approaches directed specifically toward vascular diseases during the past two decades. Analysis of the promises and limitations of these approaches will help identify and optimize vascular nanomedicine systems to enhance their efficacy and clinical translation in the future. Nanomedicine-based approaches have had a major impact on the treatment and diagnosis of malignancies and vascular diseases. This review discusses various nanomedicine approaches directed specifically toward vascular diseases during the past two decades, highlighting their advantages, limitations and offering new perspectives on future applications. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. The vascular pattern in the flower of some Mesembryanthemaceae: Aptenia cordifolia and Dorotheanthus bellidiformis. The effect of an ontogenetical shifting on the vascular pattern and vascular conservatism

    NARCIS (Netherlands)

    Meulen-Bruijns, van der C.

    1976-01-01

    1. The vascular pattern in the flower at various stages of maturity of Aptenia cordifolia and Dorotheanthus bellidiformis is examined. 2. The vascular pattern of Dorotheanthus has been compared with that of Aptenia: typologically, Dorotheanthus is derived from Aptenia. 3. The vascular pattern of

  5. Vascular training and endovascular practice in Europe

    DEFF Research Database (Denmark)

    Liapis, C.D.; Avgerinos, E.D.; Sillesen, H.

    2009-01-01

    specialties was distributed to a VS educator within 14 European countries. European Vascular and Endovascular Monitor (EVEM) data also were processed to correlate endovascular practice with training models. RESULTS: Fourteen questionnaires were gathered. Vascular training in Europe appears in 3 models: 1....... Mono-specialty (independence): 7 countries, 2. Subspecialty: 5 countries, 3. An existing specialty within general surgery: 2 countries. Independent compared to non-independent certification shortens overall training length (5.9 vs 7.9 years, p=0.006), while increasing overall training devoted......% respectively. Countries with independent vascular certification, despite their lower average endovascular index (procedures per 100,000 population), reported a higher growth rate of aortic endovascular procedures (VS independent 132% vs VS non-independent 87%), within a four-year period (2003-2007). Peripheral...

  6. Intraoperative digital angiography: Peripheral vascular applications

    International Nuclear Information System (INIS)

    Bell, K.; Reifsteck, J.E.; Binet, E.F.; Fleisher, H.J.

    1986-01-01

    Intraoperative digital angiography is the procedure of choice for the peripheral vascular surgeon who wishes to evaluate his results before terminating anesthesia. Two operating suites at the John L. McClellan Memorial Veterans Hospital are equipped with permanent ceiling-mounted Philips C-arm fluoroscopes and share an ADAC 4100 digital angiographic system. In the last 18 months, 40 peripheral vascular intraoperative digital angiographic procedures have been performed, in all but two cases using direct arterial puncture. In 65% of cases, the intraoperative study showed no significant abnormality. In 12.5%, minor abnormalities not requiring reoperation were seen. In 22.5% of cases, the intraoperative digital angiogram revealed a significant abnormality requiring immediate operative revision. None of the patients who underwent reoperation experienced postoperative sequelae. Intraoperative digital angiography is useful in identifying complications of peripheral vascular operations

  7. Viral haemorrhagic fever and vascular alterations.

    Science.gov (United States)

    Aleksandrowicz, P; Wolf, K; Falzarano, D; Feldmann, H; Seebach, J; Schnittler, H

    2008-02-01

    Pathogenesis of viral haemorrhagic fever (VHF) is closely associated with alterations of the vascular system. Among the virus families causing VHF, filoviruses (Marburg and Ebola) are the most fatal, and will be focused on here. After entering the body, Ebola primarily targets monocytes/macrophages and dendritic cells. Infected dendritic cells are largely impaired in their activation potency, likely contributing to the immune suppression that occurs during filovirus infection. Monocytes/macrophages, however, immediately activate after viral contact and release reasonable amounts of cytokines that target the vascular system, particularly the endothelial cells. Some underlying molecular mechanisms such as alteration of the vascular endothelial cadherin/catenin complex, tyrosine phosphorylation, expression of cell adhesion molecules, tissue factor and the effect of soluble viral proteins released from infected cells to the blood stream will be discussed.

  8. Vacuum assisted closure in vascular surgery.

    Science.gov (United States)

    Beno, M; Martin, J; Sager, P

    2011-01-01

    Vacuum assisted closure (VAC-therapy) is a well established method in nearly all surgical disciplines. The aim is to present the efficiency of vacuum assisted closure in the treatment of acute and chronic wounds in patients admitted in the department of vascular surgery. Within the year 2008 there were 59 patients (44 men, 15 women) treated with VAC therapy in our Department of Vascular surgery (Landshut, Germany). VAC was used 22x (37.28 %) in therapy of ulcus cruris (venous, arterial, mixed genesis), 15x (25.42%) in patients with diabetic foot syndrome, 12x (20.33%) in secondary healing wounds and infected wounds, 5x (8.47%) in wounds after several injuries and soft skin tissue infections and 5x (8.47%) in wound infections connected with vascular graft infections after vascular revascularization. VAC therapy seems to be very effective in the management of patients with venous ulcers, especially after a proper surgical treatment (100%), patients with soft skin tissue infections (100%) and secondary healing wounds (100%) especially in combination with MESH-Grafting. In patients with diabetic foot syndrome (80%) and peripheral arterial occlusive disease (72.7%), an evaluation of peripheral blood perfusion and revascularization prior to VAC therapy is often necessary. Although VAC was used 5x in the therapy of infected vascular grafts, successful preservation of infected graft material was observed in only one case (infection of PTFE femoro-popliteal bypass graft). Vacuum assisted closure in vascular surgery proved to be simple and efficient method in therapy of acute and chronic wounds. The efficiency of VAC systems in therapy of infected graft material after revascularization needs further studies (Tab. 3, Ref. 10).

  9. The pathology and pathophysiology of vascular dementia.

    Science.gov (United States)

    Kalaria, Raj N

    2017-12-19

    Vascular dementia (VaD) is widely recognised as the second most common type of dementia. Consensus and accurate diagnosis of clinically suspected VaD relies on wide-ranging clinical, neuropsychological and neuroimaging measures in life but more importantly pathological confirmation. Factors defining subtypes of VaD include the nature and extent of vascular pathologies, degree of involvement of extra and intracranial vessels and the anatomical location of tissue changes as well as time after the initial vascular event. Atherosclerotic and cardioembolic diseases combined appear the most common subtypes of vascular brain injury. In recent years, cerebral small vessel disease (SVD) has gained prominence worldwide as an important substrate of cognitive impairment. SVD is characterised by arteriolosclerosis, lacunar infarcts and cortical and subcortical microinfarcts and diffuse white matter changes, which involve myelin loss and axonal abnormalities. Global brain atrophy and focal degeneration of the cerebrum including medial temporal lobe atrophy are also features of VaD similar to Alzheimer's disease. Hereditary arteriopathies have provided insights into the mechanisms of dementia particularly how arteriolosclerosis, a major contributor of SVD promotes cognitive impairment. Recently developed and validated neuropathology guidelines indicated that the best predictors of vascular cognitive impairment were small or lacunar infarcts, microinfarcts, perivascular space dilation, myelin loss, arteriolosclerosis and leptomeningeal cerebral amyloid angiopathy. While these substrates do not suggest high specificity, VaD is likely defined by key neuronal and dendro-synaptic changes resulting in executive dysfunction and related cognitive deficits. Greater understanding of the molecular pathology is needed to clearly define microvascular disease and vascular substrates of dementia. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Perioperative smoking cessation in vascular surgery

    DEFF Research Database (Denmark)

    Kehlet, M.; Heesemann, Sabine; Tonnesen, H.

    2015-01-01

    Background: The effect of intensive smoking cessation programs on postoperative complications has never before been assessed in soft tissue surgery when smoking cessation is initiated on the day of surgery. Methods: A single-blinded randomized clinical trial conducted at two vascular surgery...... departments in Denmark. The intervention group was offered the Gold Standard Program (GSP) for smoking cessation intervention. The control group was offered the departments' standard care. Inclusion criteria were patients with planned open peripheral vascular surgery and who were daily smokers. According...

  11. Genealogy of training in vascular neurosurgery.

    Science.gov (United States)

    Chowdhry, Shakeel A; Spetzler, Robert F

    2014-02-01

    Remarkable advances and changes in the landscape of neurovascular disease have occurred recently. Concurrently, a paradigm shift in training and resident education is underway. This crossroad of unique opportunities and pressures necessitates creative change in the training of future vascular neurosurgeons to allow incorporation of surgical advances, new technology, and supplementary treatment modalities in a setting of reduced work hours and increased public scrutiny. This article discusses the changing landscape in neurovascular disease treatment, followed by the recent changes in resident training, and concludes with our view of the future of training in vascular neurosurgery.

  12. Vascularized Composite Allografts: Procurement, Allocation, and Implementation.

    Science.gov (United States)

    Rahmel, Axel

    Vascularized composite allotransplantation is a continuously evolving area of modern transplant medicine. Recently, vascularized composite allografts (VCAs) have been formally classified as 'organs'. In this review, key aspects of VCA procurement are discussed, with a special focus on interaction with the procurement of classical solid organs. In addition, options for a matching and allocation system that ensures VCA donor organs are allocated to the best-suited recipients are looked at. Finally, the different steps needed to promote VCA transplantation in society in general and in the medical community in particular are highlighted.

  13. Early vascular plants in the Czech Republic

    OpenAIRE

    Uhlířová, Monika

    2017-01-01

    Vascular plants are characterized as a group of plants, which are already fully adapted to live on the land. Their evolution is a result of a set of adaptations that have required the necessary changes at anatomical and morphological level. Some evidences about the rise of vascular plants appear in the fossil record from the Middle Ordovician in the form of spores and later also from the Early Silurian in the form of megafossils. The aim of the thesis is to briefly describe and discuss the mo...

  14. Radiological study of cerebro-vascular accidents

    International Nuclear Information System (INIS)

    Misri, H.T.; Kabawe, Bassam

    1991-01-01

    The role of computerized tomography scanner in studying the cerebro-vascular accidents has been discussed. One hundred fifty patients with cerebro-vascular accidents were studied at Aleppo University Hospital between 1989-1990. Clinical history and physical examination were recorded, as well as, computerized tomography scanning in all cases without using the contrast media mostly. Relationship between the density of the lesion (inforctionor hemorrhage) and the time has been found. This relationship can help in forensic medicine. (author). 29 refs., 5 tabs., 2 figs

  15. Angiogenesis and vascular targeting: Relevance for hyperthermia

    DEFF Research Database (Denmark)

    Horsman, Michael R

    2008-01-01

    The creation of a functional blood supply from the normal tissue vasculature via the process of angiogenesis is critical for the continued growth and development of solid tumours. This importance has led to the concept of targeting the tumour vasculature as a therapeutic strategy, and two major...... types of vascular targeting agents (VTAs) have developed; those that inhibit the angiogenic process-angiogenesis inhibiting agents (AIAs)-and those that specifically damage the already established neovasculature-vascular disrupting agents (VDAs). The tumour vasculature also plays a critical role...

  16. Age related changes in tumor vascularity

    International Nuclear Information System (INIS)

    Loerelius, L.E.; Stridbeck, H.

    1984-01-01

    VX 2 tumors in the rabbit hind leg were investigated at one, two and three weeks of age. Angiograms were compared with vascular casts. The tumors grew rapidly the first two weeks of age. Large variations in vascularity were noted between tumors of different ages. With increasing age arteriovenous shunts at the tumor periphery and areas of avascularity of necrosis in the tumor center increased in size. Possible reasons for tumor necrosis are increased tissue pressure, anoxia caused by arteriovenous shunts and elevation in venous pressure. The natural history of the VX 2 tumor must be considered in every experimental study of the effect of any treatment. (orig.)

  17. Improving Technology for Vascular Imaging

    Science.gov (United States)

    Rana, Raman

    Neuro-endovascular image guided interventions (Neuro-EIGIs) is a minimally invasive procedure that require micro catheters and endovascular devices be inserted into the vasculature via an incision near the femoral artery and guided under low dose fluoroscopy to the vasculature of the head and neck. However, the endovascular devices used for the purpose are of very small size (stents are of the order of 50mum to 100mum) and the success of these EIGIs depends a lot on the accurate placement of these devices. In order to accurately place these devices inside the patient, the interventionalist should be able to see them clearly. Hence, high resolution capabilities are of immense importance in neuro-EIGIs. The high-resolution detectors, MAF-CCD and MAF-CMOS, at the Toshiba Stroke and Vascular Research Center at the University at Buffalo are capable of presenting improved images for better patient care. Focal spot of an x-ray tube plays an important role in performance of these high resolution detectors. The finite size of the focal spot results into the blurriness around the edges of the image of the object resulting in reduced spatial resolution. Hence, knowledge of accurate size of the focal spot of the x-ray tube is very essential for the evaluation of the total system performance. Importance of magnification and image detector blur deconvolution was demonstrated to carry out the more accurate measurement of x-ray focal spot using a pinhole camera. A 30 micron pinhole was used to obtain the focal spot images using flat panel detector (FPD) and different source to image distances (SIDs) were used to achieve different magnifications (3.16, 2.66 and 2.16). These focal spot images were deconvolved with a 2-D modulation transfer function (MTF), obtained using noise response (NR) method, to remove the detector blur present in the images. Using these corrected images, the accurate size of all the three focal spots were obtained and it was also established that effect of

  18. Interventional Radiological Treatment of Perihepatic Vascular Stenosis or Occlusion in Pediatric Patients After Liver Transplantation

    International Nuclear Information System (INIS)

    Uller, Wibke; Knoppke, Birgit; Schreyer, Andreas G.; Heiss, Peter; Schlitt, Hans J.; Melter, Michael; Stroszczynski, Christian; Zorger, Niels; Wohlgemuth, Walter A.

    2013-01-01

    Purpose: Evaluation of the efficacy and safety of percutaneous treatment of vascular stenoses and occlusions in pediatric liver transplant recipients. Methods: Fifteen children (mean age 8.3 years) underwent interventional procedures for 18 vascular complications after liver transplantation. Patients had stenoses or occlusions of portal veins (n = 8), hepatic veins (n = 3), inferior vena cava (IVC; n = 2) or hepatic arteries (n = 5). Technical and clinical success rates were evaluated. Results: Stent angioplasty was performed in seven cases (portal vein, hepatic artery and IVC), and sole balloon angioplasty was performed in eight cases. One child underwent thrombolysis (hepatic artery). Clinical and technical success was achieved in 14 of 18 cases of vascular stenoses or occlusions (mean follow-up 710 days). Conclusion: Pediatric interventional radiology allows effective and safe treatment of vascular stenoses after pediatric liver transplantation (PLT). Individualized treatment with special concepts for each pediatric patient is necessary. The variety, the characteristics, and the individuality of interventional management of all kinds of possible vascular stenoses or occlusions after PLT are shown

  19. Hospital costs associated with surgical site infections in general and vascular surgery patients.

    Science.gov (United States)

    Boltz, Melissa M; Hollenbeak, Christopher S; Julian, Kathleen G; Ortenzi, Gail; Dillon, Peter W

    2011-11-01

    Although much has been written about excess cost and duration of stay (DOS) associated with surgical site infections (SSIs) after cardiothoracic surgery, less has been reported after vascular and general surgery. We used data from the National Surgical Quality Improvement Program (NSQIP) to estimate the total cost and DOS associated with SSIs in patients undergoing general and vascular surgery. Using standard NSQIP practices, data were collected on patients undergoing general and vascular surgery at a single academic center between 2007 and 2009 and were merged with fully loaded operating costs obtained from the hospital accounting database. Logistic regression was used to determine which patient and preoperative variables influenced the occurrence of SSIs. After adjusting for patient characteristics, costs and DOS were fit to linear regression models to determine the effect of SSIs. Of the 2,250 general and vascular surgery patients sampled, SSIs were observed in 186 inpatients. Predisposing factors of SSIs were male sex, insulin-dependent diabetes, steroid use, wound classification, and operative time (P surgery. Although the excess costs and DOS associated with SSIs after general and vascular surgery are somewhat less, they still represent substantial financial and opportunity costs to hospitals and suggest, along with the implications for patient care, a continuing need for cost-effective quality improvement and programs of infection prevention. Copyright © 2011 Mosby, Inc. All rights reserved.

  20. Engineering the mechanical and biological properties of nanofibrous vascular grafts for in situ vascular tissue engineering.

    Science.gov (United States)

    Henry, Jeffrey J D; Yu, Jian; Wang, Aijun; Lee, Randall; Fang, Jun; Li, Song

    2017-08-17

    Synthetic small diameter vascular grafts have a high failure rate, and endothelialization is critical for preventing thrombosis and graft occlusion. A promising approach is in situ tissue engineering, whereby an acellular scaffold is implanted and provides stimulatory cues to guide the in situ remodeling into a functional blood vessel. An ideal scaffold should have sufficient binding sites for biomolecule immobilization and a mechanical property similar to native tissue. Here we developed a novel method to blend low molecular weight (LMW) elastic polymer during electrospinning process to increase conjugation sites and to improve the mechanical property of vascular grafts. LMW elastic polymer improved the elasticity of the scaffolds, and significantly increased the amount of heparin conjugated to the micro/nanofibrous scaffolds, which in turn increased the loading capacity of vascular endothelial growth factor (VEGF) and prolonged the release of VEGF. Vascular grafts were implanted into the carotid artery of rats to evaluate the in vivo performance. VEGF treatment significantly enhanced endothelium formation and the overall patency of vascular grafts. Heparin coating also increased cell infiltration into the electrospun grafts, thus increasing the production of collagen and elastin within the graft wall. This work demonstrates that LMW elastic polymer blending is an approach to engineer the mechanical and biological property of micro/nanofibrous vascular grafts for in situ vascular tissue engineering.

  1. In-depth evaluation of commercially available human vascular smooth muscle cells phenotype: Implications for vascular tissue engineering

    International Nuclear Information System (INIS)

    Timraz, Sara B.H.; Farhat, Ilyas A.H.; Alhussein, Ghada; Christoforou, Nicolas; Teo, Jeremy C.M.

    2016-01-01

    In vitro research on vascular tissue engineering has extensively used isolated primary human or animal smooth muscle cells (SMC). Research programs that lack such facilities tend towards commercially available primary cells sources. Here, we aim to evaluate the capacity of commercially available human SMC to maintain their contractile phenotype, and determine if dedifferentiation towards the synthetic phenotype occurs in response to conventional cell culture and passaging without any external biochemical or mechanical stimuli. Lower passage SMC adopted a contractile phenotype marked by a relatively slower proliferation rate, higher expression of proteins of the contractile apparatus and smoothelin, elongated morphology, and reduced deposition of collagen types I and III. As the passage number increased, migratory capacity was enhanced, average cell speed, total distance and net distance travelled increased up to passage 8. Through the various assays, corroborative evidence pinpoints SMC at passage 7 as the transition point between the contractile and synthetic phenotypes, while passage 8 distinctly and consistently exhibited characteristics of synthetic phenotype. This knowledge is particularly useful in selecting SMC of appropriate passage number for the target vascular tissue engineering application, for example, a homeostatic vascular graft for blood vessel replacement versus recreating atherosclerotic blood vessel model in vitro. - Highlights: • Ability of human smooth muscle cells to alter phenotype in culture is evaluated. • Examined the effect of passaging human smooth muscle cells on phenotype. • Phenotype is assessed based on morphology, proliferation, markers, and migration. • Multi-resolution assessment methodology, single-cell and cell-population. • Lower and higher passages than P7 adopted a contractile and synthetic phenotype respectively.

  2. In-depth evaluation of commercially available human vascular smooth muscle cells phenotype: Implications for vascular tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Timraz, Sara B.H., E-mail: sara.timraz@kustar.ac.ae [Department of Biomedical Engineering, Khalifa University, PO Box 127788, Abu Dhabi (United Arab Emirates); Farhat, Ilyas A.H., E-mail: ilyas.farhat@outlook.com [Department of Applied Mathematics and Sciences, Khalifa University, PO Box 127788, Abu Dhabi (United Arab Emirates); Alhussein, Ghada, E-mail: ghada.alhussein@kustar.ac.ae [Department of Biomedical Engineering, Khalifa University, PO Box 127788, Abu Dhabi (United Arab Emirates); Christoforou, Nicolas, E-mail: nicolas.christoforou@kustar.ac.ae [Department of Biomedical Engineering, Khalifa University, PO Box 127788, Abu Dhabi (United Arab Emirates); Department of Biomedical Engineering, Duke University, Durham, NC 27708 (United States); Teo, Jeremy C.M., E-mail: jeremy.teo@kustar.ac.ae [Department of Biomedical Engineering, Khalifa University, PO Box 127788, Abu Dhabi (United Arab Emirates)

    2016-05-01

    In vitro research on vascular tissue engineering has extensively used isolated primary human or animal smooth muscle cells (SMC). Research programs that lack such facilities tend towards commercially available primary cells sources. Here, we aim to evaluate the capacity of commercially available human SMC to maintain their contractile phenotype, and determine if dedifferentiation towards the synthetic phenotype occurs in response to conventional cell culture and passaging without any external biochemical or mechanical stimuli. Lower passage SMC adopted a contractile phenotype marked by a relatively slower proliferation rate, higher expression of proteins of the contractile apparatus and smoothelin, elongated morphology, and reduced deposition of collagen types I and III. As the passage number increased, migratory capacity was enhanced, average cell speed, total distance and net distance travelled increased up to passage 8. Through the various assays, corroborative evidence pinpoints SMC at passage 7 as the transition point between the contractile and synthetic phenotypes, while passage 8 distinctly and consistently exhibited characteristics of synthetic phenotype. This knowledge is particularly useful in selecting SMC of appropriate passage number for the target vascular tissue engineering application, for example, a homeostatic vascular graft for blood vessel replacement versus recreating atherosclerotic blood vessel model in vitro. - Highlights: • Ability of human smooth muscle cells to alter phenotype in culture is evaluated. • Examined the effect of passaging human smooth muscle cells on phenotype. • Phenotype is assessed based on morphology, proliferation, markers, and migration. • Multi-resolution assessment methodology, single-cell and cell-population. • Lower and higher passages than P7 adopted a contractile and synthetic phenotype respectively.

  3. Vascular plugs - A key companion to Interventionists - 'Just Plug it'.

    Science.gov (United States)

    Ramakrishnan, Sivasubramanian

    2015-01-01

    Vascular plugs are ideally suited to close extra-cardiac, high flowing vascular communications. The family of vascular plugs has expanded. Vascular plugs in general have a lower profile and the newer variants can be delivered even through a diagnostic catheter. These features make them versatile and easy to use. The Amplatzer vascular plugs are also used for closing intracardiac defects including coronary arterio-venous fistula and paravalvular leakage in an off-label fashion. In this review, the features of currently available vascular plugs are reviewed along with tips and tricks of using them in the cardiac catheterization laboratory. Copyright © 2015. Published by Elsevier B.V.

  4. Oscillation of Angiogenesis and Vascular Dropout in Progressive Human Vascular Disease. [Vascular Pattern as Useful Read-Out of Complex Molecular Signaling

    Science.gov (United States)

    Parsons-Wingerter, Patricia

    2010-01-01

    When analyzed by VESsel GENeration Analysis (VESGEN) software, vascular patterns provide useful integrative read-outs of complex, interacting molecular signaling pathways. Using VESGEN, we recently discovered and published our innovative, surprising findings that angiogenesis oscillated with vascular dropout throughout progression of diabetic retinopathy, a blinding vascular disease. Our findings provide a potential paradigm shift in the current prevailing view on progression and treatment of this disease, and a new early-stage window of regenerative therapeutic opportunities. The findings also suggest that angiogenesis may oscillate with vascular disease in a homeostatic-like manner during early stages of other inflammatory progressive diseases such as cancer and coronary vascular disease.

  5. Vascular risk factors, cognitve decline, and dementia

    Directory of Open Access Journals (Sweden)

    E Duron

    2008-04-01

    Full Text Available E Duron, Olivier HanonBroca Hospital, Paris, FranceAbstract: Dementia is one of the most important neurological disorders in the elderly. Aging is associated with a large increase in the prevalence and incidence of degenerative (Alzheimer’s disease and vascular dementia, leading to a devastating loss of autonomy. In view of the increasing longevity of populations worldwide, prevention of dementia has turned into a major public health challenge. In the past decade, several vascular risk factors have been found to be associated with vascular dementia but also Alzheimer’s disease. Some longitudinal studies, have found significant associations between hypertension, diabetus mellitus, and metabolic syndrome, assessed at middle age, and dementia. Studies assessing the link between hypercholesterolemia, atrial fibrillation, smoking, and dementia have given more conflicting results. Furthermore, some studies have highlighted the possible protective effect of antihypertensive therapy on cognition and some trials are evaluating the effects of statins and treatments for insulin resistance. Vascular risk factors and their treatments are a promising avenue of research for prevention of dementia, and further long-term, placebo-controlled, randomized studies, need to be performed.Keywords: dementia, hypertension, diabetus mellitus, hypercholesterolemia, metabolic syndrome

  6. Vascular anatomy in angiography for magnetic resonance

    International Nuclear Information System (INIS)

    Charry Lopez, Marco Luciano; Rivera Gomez, Juan Enrique

    1998-01-01

    A review of basic anatomical concepts and main variants, as well as some anatomical anomalies of the central nervous system vascularity, these concepts are considered essential for the interpretation of magnetic resonance angiography with time-of-flight (TOF) and phase-contrast (PC) methods

  7. CT imaging of cervical spinal vascular malformation

    International Nuclear Information System (INIS)

    Ueda, Takashi; Iwamoto, Munehisa; Miyamoto, Etsuo; Kuriyama, Tsuyoshi; Hayama, Tsuneto

    1982-01-01

    The patient had a history of the onset of motor paralysis of the right upper and lower extremities. Eight years later, numbness of the right upper extremity and a severe neck pain developed, and transverse paralysis of the lower extremities appeared in about 10 hours. CT demonstrated the presence of spinal vascular abnormality. Angiography suggested arteriovenous malformation of glomus type. (Chiba, N.)

  8. NEURO-VASCULAR INJURIES ASSOCIATED WITH LIMB ...

    African Journals Online (AJOL)

    hi-tech

    2000-12-01

    Dec 1, 2000 ... Subjects: Forty three patients with bone fractures associated with vascular and peripheral nerve injury seen at the Emergency Room of Assir Central Hospital from 1990 to 1999. There were 39 males and four females. Thirty five of these patients (81.4%) were Saudi nationals and the rest were non-Saudi.

  9. B vitamins influence vascular cognitive impairment

    Science.gov (United States)

    As the number of elderly in the USA and globally continues to increase, age-related neurological disorders, such as Alzheimer's disease and vascular dementia, are a growing concern. The loss of memory, emotional changes, and impairments in general cognitive functioning frequently result in social is...

  10. Quality Estimation for Vascular Pattern Recognition

    DEFF Research Database (Denmark)

    Hartung, Daniel; Martin, Sophie; Busch, Christoph

    2011-01-01

    The quality of captured samples is a critical aspect in biometric systems. In this paper we present a quality estimation algorithm for vascular images, which uses global and local features based on a Grey Level Co-Occurrence Matrix (GLCM) and optionally available metadata. An evaluation of the al...

  11. Self-management of vascular risk factors

    NARCIS (Netherlands)

    Sol-de Rijk, B.G.M.

    2009-01-01

    Summary The aim of this thesis was to provide insight into the potential of a self-management approach in treatment of vascular risk factors and to develop a self-management intervention. Furthermore to examine if this intervention, based on self-efficacy promoting theory, is effective in reducing

  12. Human genetics of diabetic vascular complications

    Indian Academy of Sciences (India)

    Diabetic vascular complications (DVC) affecting several important organ systems of human body such as the cardiovascular system constitute a major public health problem. There is evidence demonstrating that genetic factors contribute to the risk of DVC genetic variants, structural variants, and epigenetic changes play ...

  13. CT imaging of cervical spinal vascular malformation

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, Takashi; Iwamoto, Munehisa; Miyamoto, Etsuo; Kuriyama, Tsuyoshi; Hayama, Tsuneto [Wakayama Red Cross Hospital, Wakayama (Japan)

    1982-05-01

    The patient had a history of the onset of motor paralysis of the right upper and lower extremities. Eight years later, numbness of the right upper extremity and a severe neck pain developed, and transverse paralysis of the lower extremities appeared in about 10 hours. CT demonstrated the presence of spinal vascular abnormality. Angiography suggested arteriovenous malformation of glomus type.

  14. Vascular Contributions to Cognitive Impairment and Dementia

    Science.gov (United States)

    Gorelick, Philip B.; Scuteri, Angelo; Black, Sandra E.; DeCarli, Charles; Greenberg, Steven M.; Iadecola, Costantino; Launer, Lenore J.; Laurent, Stephane; Lopez, Oscar L.; Nyenhuis, David; Petersen, Ronald C.; Schneider, Julie A.; Tzourio, Christophe; Arnett, Donna K.; Bennett, David A.; Chui, Helena C.; Higashida, Randall T.; Lindquist, Ruth; Nilsson, Peter M.; Roman, Gustavo C.; Sellke, Frank W.; Seshadri, Sudha

    2013-01-01

    Background and Purpose This scientific statement provides an overview of the evidence on vascular contributions to cognitive impairment and dementia. Vascular contributions to cognitive impairment and dementia of later life are common. Definitions of vascular cognitive impairment (VCI), neuropathology, basic science and pathophysiological aspects, role of neuroimaging and vascular and other associated risk factors, and potential opportunities for prevention and treatment are reviewed. This statement serves as an overall guide for practitioners to gain a better understanding of VCI and dementia, prevention, and treatment. Methods Writing group members were nominated by the writing group co-chairs on the basis of their previous work in relevant topic areas and were approved by the American Heart Association Stroke Council Scientific Statement Oversight Committee, the Council on Epidemiology and Prevention, and the Manuscript Oversight Committee. The writing group used systematic literature reviews (primarily covering publications from 1990 to May 1, 2010), previously published guidelines, personal files, and expert opinion to summarize existing evidence, indicate gaps in current knowledge, and, when appropriate, formulate recommendations using standard American Heart Association criteria. All members of the writing group had the opportunity to comment on the recommendations and approved the final version of this document. After peer review by the American Heart Association, as well as review by the Stroke Council leadership, Council on Epidemiology and Prevention Council, and Scientific Statements Oversight Committee, the statement was approved by the American Heart Association Science Advisory and Coordinating Committee. Results The construct of VCI has been introduced to capture the entire spectrum of cognitive disorders associated with all forms of cerebral vascular brain injury—not solely stroke—ranging from mild cognitive impairment through fully developed

  15. Risk Stratification for the Development of Respiratory Adverse Events Following Vascular Surgery Using the Society of Vascular Surgery’s Vascular Quality Initiative

    Science.gov (United States)

    Genovese, Elizabeth A; Fish, Larry; Chaer, Rabih A; Makaroun, Michel S; Baril, Donald T

    2017-01-01

    Objective Post-operative respiratory adverse events (RAEs) are associated with high rates of morbidity and mortality in general surgery, however little is known about these complications in the vascular surgery population, a frail subset with multiple comorbidities. The objective of this study was to describe the contemporary incidence of RAEs in vascular surgery patients, the risk factors for this complication and the overall impact of RAEs on patient outcomes. Methods The Vascular Quality Initiative was queried (2003–2014) for patients who underwent endovascular abdominal aortic repair, open abdominal aortic aneurysm (AAA) repair, thoracic endovascular aortic repair (TEVAR), suprainguinal bypass or infrainguinal bypass. A mixed-effects logistic regression model determined the independent risk factors for RAEs. Using a random 85% of the cohort, a risk prediction score for RAEs was created and the score was validated using the remaining 15% of the cohort, comparing the predicted to the actual incidence of RAE and determining the area under the receiver operating characteristic curve. The independent risk of in-hospital mortality and discharge to a nursing facility associated with RAEs was determined using a mixed-effects logistic regression to control for baseline patient characteristics, operative variables and other post-operative adverse events. Results The cohort consisted of 52,562 patients, with a 5.4% incidence of RAEs. The highest rates of RAEs were seen in current smokers (6.1%), recent acute myocardial infarction (10.1%), symptomatic congestive heart failure (CHF) (9.9%), chronic obstructive pulmonary disease (COPD) requiring oxygen therapy (11.0%), urgent and emergent procedures (6.4% and 25.9%, respectively), open AAA repairs (17.6%), in-situ suprainguinal bypasses (9.68%) and TEVARs (9.6%). The variables included in the risk prediction score were age, body mass index, smoking status, CHF severity, COPD severity, degree of renal insufficiency

  16. Coexistence of pheochromocytoma with uncommon vascular lesions

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Kota

    2012-01-01

    Full Text Available Background: Pheochromocytoma/paragangliomas have been described to be associated with rare vascular abnormalities like renal artery stenosis. Coexistence of physiologically significant renal artery lesions is a compounding factor that alters management and prognosis of pheochromocytoma patients. Apart from individual case reports, data on such association in Indian population is not available. The aim of this study is to find the nature and prevalence of associated vascular abnormalities. Materials and Methods: From 1990 to 2010, a total of 50 patients were diagnosed with pheochromocytoma/paragangliomas. Hospital charts of these patients were reviewed retrospectively to identify those with unusual vascular abnormalities. Available literature was also reviewed. Results: Of the 50 patients with pheochromocytoma, 7 (14% had coexisting vascular lesions including renal artery stenosis in 4, aortoarteritis in 1, aortic aneurysm in 1 and inferior vena cava thrombosis in 1. Pheochromocytoma was adrenal in 42 and extra adrenal in 8. Laparoscopic adrenalectomy was done in the patients. One patient with renal artery stenosis due to intimal fibrosis was subjected to percutaneous balloon angioplasty; the other three improved after adrenalectomy and lysis of fibrous adhesive bands. The patient with aortoarteritos was treated with oral steroids. Inferior vena cava thrombosis was reversed with anticoagulants. The patient with abdominal aortic aneurysm was advised for annual follow-up on account of its size of 4.5 cm and asymptomatic presentation. Conclusion: There are multiple mechanisms that can lead to renal artery stenosis and other vascular abnormalities in a case of pheochromocytoma. A high index of suspicion is necessary to enable both entities to be diagnosed preoperatively and allow proper planning of surgical therapy. Incomplete diagnosis may lead to persistent hypertension postoperatively in a case of associated renal artery stenosis.

  17. A biodegradable vascularizing membrane: a feasibility study.

    Science.gov (United States)

    Kaushiva, Anchal; Turzhitsky, Vladimir M; Darmoc, Marissa; Backman, Vadim; Ameer, Guillermo A

    2007-09-01

    Regenerative medicine and in vivo biosensor applications require the formation of mature vascular networks for long-term success. This study investigated whether biodegradable porous membranes could induce the formation of a vascularized fibrous capsule and, if so, the effect of degradation kinetics on neovascularization. Poly(l-lactic acid) (PLLA) and poly(dl-lactic-co-glycolic) acid (PLGA) membranes were created by a solvent casting/salt leaching method. Specifically, PLLA, PLGA 75:25 and PLGA 50:50 polymers were used to vary degradation kinetics. The membranes were designed to have an average 60mum pore diameter, as this pore size has been shown to be optimal for inducing blood vessel formation around nondegradable polymer materials. Membrane samples were imaged by scanning electron microscopy at several time points during in vitro degradation to assess any changes in pore structure. The in vivo performance of the membranes was assessed in Sprague-Dawley rats by measuring vascularization within the fibrous capsule that forms adjacent to implants. The vascular density within 100microm of the membranes was compared with that seen in normal tissue, and to that surrounding the commercially available vascularizing membrane TheraCyte. The hemoglobin content of tissue containing the membranes was measured by four-dimensional elastic light scattering as a novel method to assess tissue perfusion. Results from this study show that slow-degrading membranes induce greater amounts of neovascularization and a thinner fibrous capsule relative to fast degrading membranes. These results may be due both to an initially increased number of macrophages surrounding the slower degrading membranes and to the maintenance of their initial pore structure.

  18. Advanced Maternal Age Worsens Postpartum Vascular Function

    Directory of Open Access Journals (Sweden)

    Jude S. Morton

    2017-06-01

    Full Text Available The age at which women experience their first pregnancy has increased throughout the decades. Pregnancy has an important influence on maternal short- and long-term cardiovascular outcomes. Pregnancy at an advanced maternal age increases maternal risk of gestational diabetes, preeclampsia, placenta previa and caesarian delivery; complications which predict worsened cardiovascular health in later years. Aging also independently increases the risk of cardiovascular disease; therefore, combined risk in women of advanced maternal age may lead to detrimental cardiovascular outcomes later in life. We hypothesized that pregnancy at an advanced maternal age would lead to postpartum vascular dysfunction. We used a reproductively aged rat model to investigate vascular function in never pregnant (virgin, previously pregnant (postpartum and previously mated but never delivered (nulliparous rats at approximately 13.5 months of age (3 months postpartum or equivalent. Nulliparous rats, in which pregnancy was spontaneously lost, demonstrated significantly reduced aortic relaxation responses (methylcholine [MCh] Emax: 54.2 ± 12.6% vs. virgin and postpartum rats (MCh Emax: 84.8 ± 3.5% and 84.7 ± 3.2% respectively; suggesting pregnancy loss causes a worsened vascular pathology. Oxidized LDL reduced relaxation to MCh in aorta from virgin and postpartum, but not nulliparous rats, with an increased contribution of the LOX-1 receptor in the postpartum group. Further, in mesenteric arteries from postpartum rats, endothelium-derived hyperpolarization (EDH-mediated vasodilation was reduced and a constrictive prostaglandin effect was apparent. In conclusion, aged postpartum rats exhibited vascular dysfunction, while rats which had pregnancy loss demonstrated a distinct vascular pathology. These data demonstrate mechanisms which may lead to worsened outcomes at an advanced maternal age; including early pregnancy loss and later life cardiovascular dysfunction.

  19. Endovascular Management of Vascular Injury during Transsphenoidal Surgery

    OpenAIRE

    Çinar, C.; Bozkaya, H.; Parildar, M.; Oran, I.

    2013-01-01

    Vascular injury is an unusual and serious complication of transsphenoidal surgery. We aimed to define the role of angiography and endovascular treatment in patients with vascular injuries occurring during transsphenoidal surgery.

  20. Vascular effects of a single high salt meal

    Directory of Open Access Journals (Sweden)

    Mohamed Abdel Kader Abdel Wahab

    2016-09-01

    Conclusion: High salt intake may acutely impair vascular function in different vascular beds independent of the increase of blood pressure. Plasma sodium increase may be one of the underlying mechanisms.

  1. Vascular surgery research in the Gulf Cooperation Council countries

    Directory of Open Access Journals (Sweden)

    Ali Jawas

    2014-04-01

    Conclusion: The quality and quantity of vascular surgery research in the GCC countries should be improved to answer important local questions related to vascular diseases. This needs better strategic planning and more collaboration between various institutions.

  2. Estrogen, vascular estrogen receptor and hormone therapy in postmenopausal vascular disease.

    Science.gov (United States)

    Khalil, Raouf A

    2013-12-15

    Cardiovascular disease (CVD) is less common in premenopausal women than men of the same age or postmenopausal women, suggesting vascular benefits of estrogen. Estrogen activates estrogen receptors ERα, ERβ and GPR30 in endothelium and vascular smooth muscle (VSM), which trigger downstream signaling pathways and lead to genomic and non-genomic vascular effects such as vasodilation, decreased VSM contraction and growth and reduced vascular remodeling. However, randomized clinical trials (RCTs), such as the Women's Health Initiative (WHI) and Heart and Estrogen/progestin Replacement Study (HERS), have shown little vascular benefits and even adverse events with menopausal hormone therapy (MHT), likely due to factors related to the MHT used, ER profile, and RCT design. Some MHT forms, dose, combinations or route of administration may have inadequate vascular effects. Age-related changes in ER amount, distribution, integrity and post-ER signaling could alter the vascular response to MHT. The subject's age, preexisting CVD, and hormone environment could also reduce the effects of MHT. Further evaluation of natural and synthetic estrogens, phytoestrogens, and selective estrogen-receptor modulators (SERMs), and the design of appropriate MHT combinations, dose, route and 'timing' could improve the effectiveness of conventional MHT and provide alternative therapies in the peri-menopausal period. Targeting ER using specific ER agonists, localized MHT delivery, and activation of specific post-ER signaling pathways could counter age-related changes in ER. Examination of the hormone environment and conditions associated with hormone imbalance such as polycystic ovary syndrome may reveal the causes of abnormal hormone-receptor interactions. Consideration of these factors in new RCTs such as the Kronos Early Estrogen Prevention Study (KEEPS) could enhance the vascular benefits of estrogen in postmenopausal CVD. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Cell sheet engineering using the stromal vascular fraction of adipose tissue as a vascularization strategy

    OpenAIRE

    Costa, M.; Cerqueira, Mariana Teixeira; Santos, T. C.; Marques, Belém Sampaio; Ludovico, Paula; Marques, A. P.; Pirraco, Rogério P.; Reis, R. L.

    2017-01-01

    Current vascularization strategies for Tissue Engineering constructs, in particular cell sheet-based, are limited by time-consuming and expensive endothelial cell isolation and/or by the complexity of using extrinsic growth factors. Herein, we propose an alternative strategy using angiogenic cell sheets (CS) obtained from the stromal vascular fraction (SVF) of adipose tissue that can be incorporated into more complex constructs. Cells from the SVF were cultured in normoxic and hypoxic conditi...

  4. VA Vascular Injury Study (VAVIS): VA-DoD extremity injury outcomes collaboration.

    Science.gov (United States)

    Shireman, Paula K; Rasmussen, Todd E; Jaramillo, Carlos A; Pugh, Mary Jo

    2015-02-03

    Limb injuries comprise 50-60% of U.S. Service member's casualties of wars in Afghanistan and Iraq. Combat-related vascular injuries are present in 12% of this cohort, a rate 5 times higher than in prior wars. Improvements in medical and surgical trauma care, including initial in-theatre limb salvage approaches (IILS) have resulted in improved survival and fewer amputations, however, the long-term outcomes such as morbidity, functional decline, and risk for late amputation of salvaged limbs using current process of care have not been studied. The long-term care of these injured warfighters poses a significant challenge to the Department of Defense (DoD) and Department of Veterans Affairs (VA). The VA Vascular Injury Study (VAVIS): VA-DoD Extremity Injury Outcomes Collaborative, funded by the VA, Health Services Research and Development Service, is a longitudinal cohort study of Veterans with vascular extremity injuries. Enrollment will begin April, 2015 and continue for 3 years. Individuals with a validated extremity vascular injury in the Department of Defense Trauma Registry will be contacted and will complete a set of validated demographic, social, behavioral, and functional status measures during interview and online/ mailed survey. Primary outcome measures will: 1) Compare injury, demographic and geospatial characteristics of patients with IILS and identify late vascular surgery related limb complications and health care utilization in Veterans receiving VA vs. non-VA care, 2) Characterize the preventive services received by individuals with vascular repair and related outcomes, and 3) Describe patient-reported functional outcomes in Veterans with traumatic vascular limb injuries. This study will provide key information about the current process of care for Active Duty Service members and Veterans with polytrauma/vascular injuries at risk for persistent morbidity and late amputation. The results of this study will be the first step for clinicians in VA and

  5. Deficiency of superoxide dismutase promotes cerebral vascular hypertrophy and vascular dysfunction in hyperhomocysteinemia.

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    Sanjana Dayal

    Full Text Available There is an emerging consensus that hyperhomocysteinemia is an independent risk factor for cerebral vascular disease and that homocysteine-lowering therapy protects from ischemic stroke. However, the mechanisms by which hyperhomocysteinemia produces abnormalities of cerebral vascular structure and function remain largely undefined. Our objective in this study was to define the mechanistic role of superoxide in hyperhomocysteinemia-induced cerebral vascular dysfunction and hypertrophy. Unlike previous studies, our experimental design included a genetic approach to alter superoxide levels by using superoxide dismutase 1 (SOD1-deficient mice fed a high methionine/low folate diet to produce hyperhomocysteinemia. In wild-type mice, the hyperhomocysteinemic diet caused elevated superoxide levels and impaired responses to endothelium-dependent vasodilators in cerebral arterioles, and SOD1 deficiency compounded the severity of these effects. The cross-sectional area of the pial arteriolar wall was markedly increased in mice with SOD1 deficiency, and the hyperhomocysteinemic diet sensitized SOD1-deficient mice to this hypertrophic effect. Analysis of individual components of the vascular wall demonstrated a significant increase in the content of smooth muscle and elastin. We conclude that superoxide is a key driver of both cerebral vascular hypertrophy and vasomotor dysfunction in this model of dietary hyperhomocysteinemia. These findings provide insight into the mechanisms by which hyperhomocysteinemia promotes cerebral vascular disease and ischemic stroke.

  6. Using biplanar fluoroscopy to guide radiopaque vascular injections: a new method for vascular imaging.

    Directory of Open Access Journals (Sweden)

    Haley D O'Brien

    Full Text Available Studying vascular anatomy, especially in the context of relationships with hard tissues, is of great interest to biologists. Vascular studies have provided significant insight into physiology, function, phylogenetic relationships, and evolutionary patterns. Injection of resin or latex into the vascular system has been a standard technique for decades. There has been a recent surge in popularity of more modern methods, especially radiopaque latex vascular injection followed by CT scanning and digital "dissection." This technique best displays both blood vessels and bone, and allows injections to be performed on cadaveric specimens. Vascular injection is risky, however, because it is not a standardizable technique, as each specimen is variable with regard to injection pressure and timing. Moreover, it is not possible to view the perfusion of injection medium throughout the vascular system of interest. Both data and rare specimens can therefore be lost due to poor or excessive perfusion. Here, we use biplanar video fluoroscopy as a technique to guide craniovascular radiopaque latex injection. Cadaveric domestic pigs (Sus scrofa domestica and white-tailed deer (Odocoileus virginianus were injected with radiopaque latex under guidance of fluoroscopy. This method was found to enable adjustments, in real-time, to the rate, location, and pressure at which latex is injected in order to avoid data and specimen loss. In addition to visualizing the injection process, this technique can be used to determine flow patterns, and has facilitated the development of consistent markers for complete perfusion.

  7. Joint Global War on Terror (GWOT) Vascular Injury Study 2

    Science.gov (United States)

    2017-02-01

    acquired in Iraq and Afghanistan, Society for Trauma Nurse, 2-4 April 2014, poster presentation o Vascular discharge education and follow-up care...eventual quality of limb and psychological recovery or well-being. 15. SUBJECT TERMS extremity vascular injury, extremity, vascular injury, vascular... psychological recovery or well-being. Finally, this program aims to characterize and compare the physical and emotional burden in large cohorts of US

  8. Childhood Vascular Tumors Treatment (PDQ®)—Patient Version

    Science.gov (United States)

    Childhood vascular tumors form from cells that make blood vessels or lymph vessels. They can be benign (not cancer) or malignant (cancer). Get information about the symptoms, tests to diagnose, prognosis, and treatment of the most common type of vascular tumor, infantile hemangioma, and other vascular tumors in this expert-reviewed summary.

  9. The evolution of development of vascular cambia and secondary growth

    Science.gov (United States)

    Andrew Groover; Rachel Spicer

    2010-01-01

    Secondary growth from vascular cambia results in radial, woody growth of stems. The innovation of secondary vascular development during plant evolution allowed the production of novel plant forms ranging from massive forest trees to flexible, woody lianas. We present examples of the extensive phylogenetic variation in secondary vascular growth and discuss current...

  10. Development of the Australasian vascular surgical audit.

    Science.gov (United States)

    Bourke, Bernie M; Beiles, Charles Barry; Thomson, Ian A; Grigg, Michael J; Fitridge, Rob

    2012-01-01

    The purpose of this study was to describe the development of the Australasian Vascular Audit that was created to unify audit activities under the umbrella of the Australian and New Zealand Society for Vascular Surgery as a Web-based application. Constitutional change in late 2008 deemed participation in this audit compulsory for Society members. The Web-based application was developed and tested during 2009. Data for all open vascular surgery and for all endovascular procedures are collected at two points in the admission episode: at the time of operation and at discharge, and entered into the application. Data are analyzed to produce risk-adjusted outcomes. An algorithm has been developed to deal with outliers according to natural justice and to comply with the requirements of regulatory bodies. The Audit is protected by legislated privilege and is officially endorsed and indemnified by the Royal Australasian College of Surgeons. Confidentiality of surgeons and patients alike is ensured by a legally protected coding system and computer encryption system. Validation is by a verification process of 5% of members per year who are randomly selected. The application is completely funded by the Society. Data entry commenced on January 1, 2010. Over 40,000 vascular procedures were entered in the first year. The Audit application allows instantaneous on-line access to individual data and to deidentified group data and specific reports. It also allows real-time instantaneous production of log books for vascular trainees. The Audit has already gained recognition in the Australasian public arena during its first year of operation as an important benchmark of correct professional surgical behavior. Compliance has been extremely high in public hospitals but less so in private hospitals such that only 60% of members received a certificate of complete participation at the end of its first year of operation. An Internet-based compulsory audit of complete surgical practice is

  11. Management of vascular trauma from dog bites.

    Science.gov (United States)

    Akingba, A George; Robinson, Eric A; Jester, Andrea L; Rapp, Brian M; Tsai, Anthony; Motaganahalli, Raghu L; Dalsing, Michael C; Murphy, Michael P

    2013-11-01

    Vascular trauma from large-dog bites present with a combination of crush and lacerating injuries to the vessel, as well as significant adjacent soft tissue injury and a high potential for wound complications. This retrospective case series evaluates our 15 years of experience in managing this uncommonly seen injury into suggested treatment recommendations. From our database, 371 adult patients presented with dog bites between July 1997 and June 2012. Twenty (5.4%) of those patients had vascular injuries requiring surgical intervention. Patient demographics, anatomic location of injury, clinical presentation, imaging modality, method of repair, and complication rates were reviewed to assess efficacy in preserving limb function. Pediatric patients were managed at the regional children's hospital and, therefore, not included in this study. Among the 20 surgically treated vascular injuries, there were 13 arterial-only injuries, two venous-only injuries, and five combination arterial and venous injuries. Seventeen patients (85%) had upper extremity injuries; three patients had lower extremity injuries (15%). The axillobrachial artery was the most commonly injured single vessel (n = 9/20; 45%), followed by the radial artery (n = 4/20; 20%). Surgical repair of vascular injuries consisted of resection and primary anastomosis (four), interposition bypass of artery with autogenous vein (13), and ligation (two), with (one) being a combination of bypass and ligation. All patients had debridement of devitalized tissue combined with pulse lavage irrigation and perioperative antibiotics. Associated injuries requiring repair included muscle and skin (n = 10/20; 50%), bone (n = 1/20; 5%), nerve (n = 1/20; 5%), and combinations of the three (n = 5/20; 25%). Postoperative antibiotic therapy was administered for 14.7 ± 8.2 days in all 20 patients. Four patients (20%) developed postoperative wound infections, although this did not compromise their vascular repair. Of the patients

  12. The experimental studies of Chinese herbs as a vascular embolization agent for the hepatic arteries

    International Nuclear Information System (INIS)

    Chen Ziqian; Yang Xizhang; Shen Junjie; Wang Shudong; Zheng Xiaogang; Cao Jianmin

    2006-01-01

    Objective: To study the efficacy, safety and correlative characteristics of Chinese herb as a vascular embolization agent. Methods: Vascular embolization agent combined from several kinds of Chinese herb was manufactured and served as anticarcinogen and coagulant according to the chinese Pharmacopoeia. The characteristics of the combination embolization agent through embolizing the hepatic arteries in eight pigs were studied. Results: The combination agent was a non-homogenous suspension, easily to be injected through 5-F catheter with hyper attenuation under fluoroscopy; simultaneously with good histocompatibility and hemo-compatibility and without feverish response and toxicity. The combination agent mainly embolized the peripheral arteries with maintaining occlusion for 5 weeks and without formation of collateral circulation. Slight injuries of normal hepatic tissues with hepatic cytonecrosis and endochyloma focal necrosis were found through optical and electronic microscopy. Conclusions: The Chinese herb combination agent is safe and effective in experimental application with good angioembolic function and a potential peripheral embolization agent. (authors)

  13. Validity of administrative database code algorithms to identify vascular access placement, surgical revisions, and secondary patency.

    Science.gov (United States)

    Al-Jaishi, Ahmed A; Moist, Louise M; Oliver, Matthew J; Nash, Danielle M; Fleet, Jamie L; Garg, Amit X; Lok, Charmaine E

    2018-03-01

    We assessed the validity of physician billing codes and hospital admission using International Classification of Diseases 10th revision codes to identify vascular access placement, secondary patency, and surgical revisions in administrative data. We included adults (≥18 years) with a vascular access placed between 1 April 2004 and 31 March 2013 at the University Health Network, Toronto. Our reference standard was a prospective vascular access database (VASPRO) that contains information on vascular access type and dates of placement, dates for failure, and any revisions. We used VASPRO to assess the validity of different administrative coding algorithms by calculating the sensitivity, specificity, and positive predictive values of vascular access events. The sensitivity (95% confidence interval) of the best performing algorithm to identify arteriovenous access placement was 86% (83%, 89%) and specificity was 92% (89%, 93%). The corresponding numbers to identify catheter insertion were 84% (82%, 86%) and 84% (80%, 87%), respectively. The sensitivity of the best performing coding algorithm to identify arteriovenous access surgical revisions was 81% (67%, 90%) and specificity was 89% (87%, 90%). The algorithm capturing arteriovenous access placement and catheter insertion had a positive predictive value greater than 90% and arteriovenous access surgical revisions had a positive predictive value of 20%. The duration of arteriovenous access secondary patency was on average 578 (553, 603) days in VASPRO and 555 (530, 580) days in administrative databases. Administrative data algorithms have fair to good operating characteristics to identify vascular access placement and arteriovenous access secondary patency. Low positive predictive values for surgical revisions algorithm suggest that administrative data should only be used to rule out the occurrence of an event.

  14. An investigation of the vascular organisation of the canine submandibular gland.

    OpenAIRE

    Lung, M A

    1993-01-01

    It is known that parasympathetic nerve stimulation elevates venous pressure in the dog submandibular gland, and that the venous pressure wave is transformed to that of the arterial pulse. The vascular arrangements and histological characteristics of the dog submandibular gland were therefore examined to establish which anatomical structures are responsible for the change in venous pressure during salivation induced by parasympathetic stimulation. The acinar and ductal circulations were found ...

  15. Detection of active bleeding from gastric antral vascular ectasia by capsule endoscopy

    OpenAIRE

    Ohira, Tetsuya; Hokama, Akira; Kinjo, Nagisa; Nakamoto, Manabu; Kobashigawa, Chiharu; Kise, Yuya; Yamashiro, Satoshi; Kinjo, Fukunori; Kuniyoshi, Yukio; Fujita, Jiro

    2013-01-01

    Gastric antral vascular ectasia (GAVE) has been recognized as one of the important causes of occult and obscure gastrointestinal bleeding. The diagnosis is typically made based on the characteristic endoscopic features, including longitudinal row of flat, reddish stripes radiating from the pylorus into the antrum that resemble the stripes on a watermelon. These appearances, however, can easily be misinterpreted as moderate to severe gastritis. Although it is believed that capsule endoscopy (C...

  16. Multinephron dynamics on the renal vascular network

    DEFF Research Database (Denmark)

    Marsh, Donald J; Wexler, Anthony S; Brazhe, Alexey

    2012-01-01

    Tubuloglomerular feedback (TGF) and the myogenic mechanism combine in each nephron to regulate blood flow and glomerular filtration rate. Both mechanisms are non-linear, generate self-sustained oscillations, and interact as their signals converge on arteriolar smooth muscle, forming a regulatory...... clusters. In-phase synchronization predominated among nephrons separated by 1 or 3 vascular nodes, and anti-phase synchronization for 5 or 7 nodes of separation. Nephron dynamics were irregular and contained low frequency fluctuations. Results are consistent with simultaneous blood flow measurements...... of both mechanisms in the regulatory ensemble, to examine the effects of network structure on nephron synchronization. Symmetry, as a property of a network, facilitates synchronization. Nephrons received blood from a symmetric electrically conductive vascular tree. Symmetry was created by using identical...

  17. Cocoa, Blood Pressure, and Vascular Function

    Science.gov (United States)

    Ludovici, Valeria; Barthelmes, Jens; Nägele, Matthias P.; Enseleit, Frank; Ferri, Claudio; Flammer, Andreas J.; Ruschitzka, Frank; Sudano, Isabella

    2017-01-01

    Cardiovascular disease (CVD) represents the most common cause of death worldwide. The consumption of natural polyphenol-rich foods, and cocoa in particular, has been related to a reduced risk of CVD, including coronary heart disease and stroke. Intervention studies strongly suggest that cocoa exerts a beneficial impact on cardiovascular health, through the reduction of blood pressure (BP), improvement of vascular function, modulation of lipid and glucose metabolism, and reduction of platelet aggregation. These potentially beneficial effects have been shown in healthy subjects as well as in patients with risk factors (arterial hypertension, diabetes, and smoking) or established CVD (coronary heart disease or heart failure). Several potential mechanisms are supposed to be responsible for the positive effect of cocoa; among them activation of nitric oxide (NO) synthase, increased bioavailability of NO as well as antioxidant, and anti-inflammatory properties. It is the aim of this review to summarize the findings of cocoa and chocolate on BP and vascular function. PMID:28824916

  18. Vascular anatomy of the spinal cord

    International Nuclear Information System (INIS)

    Thron, A.K.

    1988-01-01

    The book summarizes the anatomic guidelines of external blood supply to the spinal cord. The basic principles of arterial supply and venous drainage are illustrated by explicit schemes for quick orientation. In the first part of the book, systematic radiologic-anatomic investigations of the superficial and deep vessels of all segments of the spinal cord are introduced. The microvascular morphology is portrayed by numerous microradiographic sections in all three dimensions without overshadowing. The three-dimensional representation of the vascular architecture illustrates elementary outlines and details of arterial territories, anastomotic cross-linking as well as the capillary system, particularly the hitherto unknown structure of the medullary venous system with its functionally important anastomoses and varying regional structures. These often now radiologic-anatomic findings are discussed as to their functional and pathophysiologic impact and constitute the basic on which to improve one's understanding of vascular syndromes of the spinal cord

  19. Features and selection of vascular access devices.

    Science.gov (United States)

    Sansivero, Gail Egan

    2010-05-01

    To review venous anatomy and physiology, discuss assessment parameters before vascular access device (VAD) placement, and review VAD options. Journal articles, personal experience. A number of VAD options are available in clinical practice. Access planning should include comprehensive assessment, with attention to patient participation in the planning and selection process. Careful consideration should be given to long-term access needs and preservation of access sites. Oncology nurses are uniquely suited to perform a key role in VAD planning and placement. With knowledge of infusion therapy, anatomy and physiology, device options, and community resources, nurses can be key leaders in preserving vascular access and improving the safety and comfort of infusion therapy. Copyright 2010 Elsevier Inc. All rights reserved.

  20. Ample spectrum of vascular hepatic disease

    International Nuclear Information System (INIS)

    Camacho, Juan C; Marquez Adriana; Romero, Javier; Aguirre Diego

    2010-01-01

    Hepatic vascular diseases (HVD) are a broad spectrum of entities of low prevalence but with different clinical manifestations that may even lead to death. Its early detection and timely treatment may change the prognosis. Diagnostic imaging plays a key role and imaging findings may be typical. However, in most cases, radiologists must take into account a wide range of differential diagnosis. Computed tomography (CT) of the abdomen is one of the most useful tools for the diagnosis of HVD taking also into account the value of other imaging methods such as Doppler Ultrasound and Magnetic Resonance Imaging (MRI). HVD can be classified according to the compromised vascular structure and can be divided into venous, portal, arterial, sinusoidal and others disorders. The objective of this review is to describe the most common presentation HVD. The major imaging findings and differential diagnosis recognizing its correlation with the pathophysiological mechanisms.

  1. Cocoa, blood pressure, and vascular function.

    Science.gov (United States)

    Sudano, Isabella; Flammer, Andreas J; Roas, Susanne; Enseleit, Frank; Ruschitzka, Frank; Corti, Roberto; Noll, Georg

    2012-08-01

    The consumption of a high amount of fruits and vegetables was found to be associated with a lower risk of coronary heart disease and stroke. Epidemiologically, a similar relationship has been found with cocoa, a naturally polyphenol-rich food. Obviously, double blind randomized studies are difficult to perform with cocoa and chocolate, respectively. However, intervention studies strongly suggest that cocoa has several beneficial effects on cardiovascular health, including the lowering of blood pressure, the improvement of vascular function and glucose metabolism, and the reduction of platelet aggregation and adhesion. Several potential mechanisms through which cocoa might exert its positive effects have been proposed, among them activation of nitric oxide synthase, increased bioavailability of nitric oxide as well as antioxidant, and anti-inflammatory properties. It is the aim of this review to summarize the findings of cocoa and chocolate on blood pressure and vascular function.

  2. Vascularization of soft tissue engineering constructs

    DEFF Research Database (Denmark)

    Pimentel Carletto, Rodrigo

    nanotechnology-based paradigm for engineering vascularised liver tissue for transplantation”) and the Danish National Research Foundation and Villum Foundation’s Center for Intelligent Drug delivery and sensing Using microcontainers and Nanomechanics (Danish National Research Foundation (DNRF122).......Vascularization is recognized to be the biggest challenge for the fabrication of tissues and finally, organs in vitro. So far, several fabrication techniques have been proposed to create a perfusable vasculature within hydrogels, however, the vascularization and perfusion of hydrogels...... with mechanical properties in the range of soft tissues has not been fully achieved. My project focused on the fabrication and the active perfusion of hydrogel constructs with multi-dimensional vasculature and controlled mechanical properties targeting soft tissues. Specifically, the initial part of the research...

  3. Cocoa, Blood Pressure, and Vascular Function

    Directory of Open Access Journals (Sweden)

    Valeria Ludovici

    2017-08-01

    Full Text Available Cardiovascular disease (CVD represents the most common cause of death worldwide. The consumption of natural polyphenol-rich foods, and cocoa in particular, has been related to a reduced risk of CVD, including coronary heart disease and stroke. Intervention studies strongly suggest that cocoa exerts a beneficial impact on cardiovascular health, through the reduction of blood pressure (BP, improvement of vascular function, modulation of lipid and glucose metabolism, and reduction of platelet aggregation. These potentially beneficial effects have been shown in healthy subjects as well as in patients with risk factors (arterial hypertension, diabetes, and smoking or established CVD (coronary heart disease or heart failure. Several potential mechanisms are supposed to be responsible for the positive effect of cocoa; among them activation of nitric oxide (NO synthase, increased bioavailability of NO as well as antioxidant, and anti-inflammatory properties. It is the aim of this review to summarize the findings of cocoa and chocolate on BP and vascular function.

  4. Noninvasive studies of peripheral vascular disease

    International Nuclear Information System (INIS)

    Yao, J.S.T.

    1987-01-01

    Plethysmography probably is the oldest method for measuring blood flow. In this method, measurements are made of changes in volume of an organ or region of tissue. In the modern practice of vascular surgery, the use of plethysmography has been expanded to include detection of not only arterial occlusive disease but also carotid artery disease and venous problems. Several types of plethysmographs are now available for clinical use in the evaluation of arterial occlusions. These are volume, strain-gauge, and photoelectric plethysmographs. The water-filled volume recorder, popular in the early use of plethysmography, is now obsolete and has been replaced by the air-filled volume plethysmograph, notably, the pulse-volume recorder. For clinical application, the newer plethysmographs, such as the strain-gauge, photopletyhsmograph, and pulse-volume recorder, are now standard equipment in many vascular laboratories. They are discussed in this article

  5. Biophysical Regulation of Vascular Differentiation and Assembly

    CERN Document Server

    Gerecht, Sharon

    2011-01-01

    The ability to grow stem cells in the laboratory and to guide their maturation to functional cells allows us to study the underlying mechanisms that govern vasculature differentiation and assembly in health and disease. Accumulating evidence suggests that early stages of vascular growth are exquisitely tuned by biophysical cues from the microenvironment, yet the scientific understanding of such cellular environments is still in its infancy. Comprehending these processes sufficiently to manipulate them would pave the way to controlling blood vessel growth in therapeutic applications. This book assembles the works and views of experts from various disciplines to provide a unique perspective on how different aspects of its microenvironment regulate the differentiation and assembly of the vasculature. In particular, it describes recent efforts to exploit modern engineering techniques to study and manipulate various biophysical cues. Biophysical Regulation of Vascular Differentiation and Assembly provides an inter...

  6. Vascular endothelium receptors and transduction mechanisms

    CERN Document Server

    Gillis, C; Ryan, Una; Proceedings of the Advanced Studies Institute on "Vascular Endothelium: Receptors and Transduction Mechanisms"

    1989-01-01

    Beyond their obvious role of a barrier between blood and tissue, vascular endothelial cells are now firmly established as active and essential participants in a host of crucial physiological and pathophysiological functions. Probably the two most important factors responsible for promoting the current knowledge of endothelial functions are 1) observations in the late sixties-early seventies that many non-ventilatory properties of the lung could be attributed to the pulmonary endothelium and 2) the establishment, in the early and mid-seventies of procedures for routine culture of vascular endothelial cells. Many of these endothelial functions require the presence of receptors on the surface of the plasma membrane. There is now evidence for the existence among others of muscarinic, a-and /3-adrenergic, purine, insulin, histamine, bradykinin, lipoprotein, thrombin, paf, fibronectin, vitronectin, interleukin and albumin receptors. For some of these ligands, there is evidence only for the existence of endothelial ...

  7. Vascular anomalies of the cerebellopontine angle

    International Nuclear Information System (INIS)

    Papanagiotou, P.; Grunwald, I.Q.; Politi, M.; Struffert, T.; Ahlhelm, F.; Reith, W.

    2006-01-01

    Vascular anomalies of the cerebellopontine angle are rare compared to tumors in this area. Irritation of the trigeminal, facial, or vestibulocochlear nerve may cause trigeminal neuralgia, hemifacial spasm and vertigo, or tinnitus accordingly. Vessel loops in the cerebellopontine cisterns may cause compression at the root entry or exit zone of the cranial nerves V, VII, and VIII, a phenomenon which is called ''vascular loop syndrome.'' Megadolichobasilar artery and aneurysms of the vertebrobasilar system can also lead to dislocation and compression of the cranial nerves and brain stem. Three-dimensional CISS MR imaging and MR angiography are useful in the detection of neurovascular compression. Microvascular decompression is an effective surgical procedure in the management of compression syndromes of the cranial nerves V, VII, and VIII. (orig.) [de

  8. Molecular parallels between neural and vascular development.

    Science.gov (United States)

    Eichmann, Anne; Thomas, Jean-Léon

    2013-01-01

    The human central nervous system (CNS) features a network of ~400 miles of blood vessels that receives >20% of the body's cardiac output and uses most of its blood glucose. Many human diseases, including stroke, retinopathy, and cancer, are associated with the biology of CNS blood vessels. These vessels originate from extrinsic cell populations, including endothelial cells and pericytes that colonize the CNS and interact with glia and neurons to establish the blood-brain barrier and control cerebrovascular exchanges. Neurovascular interactions also play important roles in adult neurogenic niches, which harbor a unique population of neural stem cells that are intimately associated with blood vessels. We here review the cellular and molecular mechanisms required to establish the CNS vascular network, with a special focus on neurovascular interactions and the functions of vascular endothelial growth factors.

  9. Treatment of hemobilia by transcatheter vascular occlusion

    International Nuclear Information System (INIS)

    Vaughan, R.; Roesch, J.; Keller, F.S.; Antonovic, R.; Veterans Administration Medical Center, Portland, OR

    1984-01-01

    Four cases of hemobilia treated by transcatheter arterial occlusion are presented and reviewed with 30 similar cases reported in the literature. Transcatheter vascular occlusion successfully controlled hemorrhage in all 34 patients. No obvious liver parenchymal damage appeared in 26 patients; transient elevation of liver enzymes occurred in 6 patients (18%) including one in our series; two of the patients reviewed died of acute hepatic insufficiency following nonselective hepatic artery embolization. Hemobilia should be considered when gastrointestinal hemorrhage occurs after abdominal trauma, liver biopsy or other manipulative liver procedures. Hepatic angiography establishes the diagnosis and selective vascular occlusion is the treatment of choice for control of intractable or recurrent hemorrhage. Techniques and precautions for the diagnosis and transcatheter therapy of hemobilia are discussed. (orig.)

  10. Prediction of Major Vascular Events after Stroke

    DEFF Research Database (Denmark)

    Ovbiagele, Bruce; Goldstein, Larry B.; Amarenco, Pierre

    2014-01-01

    BACKGROUND: Identifying patients with recent stroke or transient ischemic attack (TIA) at high risk of major vascular events (MVEs; stroke, myocardial infarction, or vascular death) may help optimize the intensity of secondary preventive interventions. We evaluated the relationships between...... the baseline Framingham Coronary Risk Score (FCRS) and a novel risk prediction model and with the occurrence of MVEs after stroke or TIA in subjects enrolled in the Stroke Prevention by Aggressive Reduction in Cholesterol Level (SPARCL) trial. METHODS: Data from the 4731 subjects enrolled in the SPARCL study...... were analyzed. Hazard ratios (HRs) from Cox regression models were used to determine the risk of subsequent MVEs based on the FCRS predicting 20% or more 10-year coronary heart disease risk. The novel risk model was derived based on multivariable modeling with backward selection. Model discrimination...

  11. Vascular lesions of the vocal fold.

    Science.gov (United States)

    Gökcan, Kürşat Mustafa; Dursun, Gürsel

    2009-04-01

    The aim of the study was to present symptoms, laryngological findings, clinical course, management modalities, and consequences of vascular lesions of vocal fold. This study examined 162 patients, the majority professional voice users, with vascular lesions regarding their presenting symptoms, laryngological findings, clinical courses and treatment results. The most common complaint was sudden hoarseness with hemorrhagic polyp. Microlaryngoscopic surgery was performed in 108 cases and the main indication of surgery was the presence of vocal fold mass or development of vocal polyp during clinical course. Cold microsurgery was utilized for removal of vocal fold masses and feeding vessels cauterized using low power, pulsed CO(2) laser. Acoustic analysis of patients revealed a significant improvement of jitter, shimmer and harmonics/noise ratio values after treatment. Depending on our clinical findings, we propose treatment algorithm where voice rest and behavioral therapy is the integral part and indications of surgery are individualized for each patient.

  12. Protein Kinase C Inhibitors as Modulators of Vascular Function and Their Application in Vascular Disease

    Directory of Open Access Journals (Sweden)

    Raouf A. Khalil

    2013-03-01

    Full Text Available Blood pressure (BP is regulated by multiple neuronal, hormonal, renal and vascular control mechanisms. Changes in signaling mechanisms in the endothelium, vascular smooth muscle (VSM and extracellular matrix cause alterations in vascular tone and blood vessel remodeling and may lead to persistent increases in vascular resistance and hypertension (HTN. In VSM, activation of surface receptors by vasoconstrictor stimuli causes an increase in intracellular free Ca2+ concentration ([Ca2+]i, which forms a complex with calmodulin, activates myosin light chain (MLC kinase and leads to MLC phosphorylation, actin-myosin interaction and VSM contraction. Vasoconstrictor agonists could also increase the production of diacylglycerol which activates protein kinase C (PKC. PKC is a family of Ca2+-dependent and Ca2+-independent isozymes that have different distributions in various blood vessels, and undergo translocation from the cytosol to the plasma membrane, cytoskeleton or the nucleus during cell activation. In VSM, PKC translocation to the cell surface may trigger a cascade of biochemical events leading to activation of mitogen-activated protein kinase (MAPK and MAPK kinase (MEK, a pathway that ultimately increases the myofilament force sensitivity to [Ca2+]i, and enhances actin-myosin interaction and VSM contraction. PKC translocation to the nucleus may induce transactivation of various genes and promote VSM growth and proliferation. PKC could also affect endothelium-derived relaxing and contracting factors as well as matrix metalloproteinases (MMPs in the extracellular matrix further affecting vascular reactivity and remodeling. In addition to vasoactive factors, reactive oxygen species, inflammatory cytokines and other metabolic factors could affect PKC activity. Increased PKC expression and activity have been observed in vascular disease and in certain forms of experimental and human HTN. Targeting of vascular PKC using PKC inhibitors may function in

  13. Improved vascularization of planar membrane diffusion devices following continuous infusion of vascular endothelial growth factor.

    Science.gov (United States)

    Trivedi, N; Steil, G M; Colton, C K; Bonner-Weir, S; Weir, G C

    2000-01-01

    Improving blood vessel formation around an immunobarrier device should improve the survival of the encapsulated tissue. In the present study we investigated the formation of new blood vessels around a planar membrane diffusion device (the Baxter Theracyte System) undergoing a continuous infusion of vascular endothelial growth factor through the membranes and into the surrounding tissue. Each device (20 microl) had both an inner immunoisolation membrane and an outer vascularizing membrane. Human recombinant vascular endothelial growth factor-165 was infused at 100 ng/day (low dose: n = 6) and 500 ng/day (high dose: n = 7) for 10 days into devices implanted s.c. in Sprague-Dawley rats; noninfused devices transplanted for an identical period were used as controls (n = 5). Two days following the termination of VEGF infusion, devices were loaded with 20 microl of Lispro insulin (1 U/kg) and the kinetics of insulin release from the lumen of the device was assessed. Devices were then explanted and the number of blood vessels (capillary and noncapillary) was quantified using morphometry. High-dose vascular endothelial growth factor infusion resulted in two- to threefold more blood vessels around the device than that obtained with the noninfused devices and devices infused with low-dose vascular endothelial growth factor. This increase in the number of blood vessels was accompanied by a modest increase in insulin diffusion from the device in the high-dose vascular endothelial growth factor infusion group. We conclude that vascular endothelial growth factor can be used to improve blood vessel formation adjacent to planar membrane diffusion devices.

  14. Binswanger's disease: biomarkers in the inflammatory form of vascular cognitive impairment and dementia.

    Science.gov (United States)

    Rosenberg, Gary A

    2018-03-01

    Vascular cognitive impairment and dementia (VCID) is a major public health concern because of the increased incidence of vascular disease in the aging population and the impact of vascular disease on Alzheimer's disease. VCID is a heterogeneous group of diseases for which there are no proven treatments. Biomarkers can be used to select more homogeneous populations. Small vessel disease is the most prevalent form of VCID and is the optimal form for treatment trials because there is a progressive course with characteristic pathological changes. Subcortical ischemic vascular disease of the Binswanger type (SIVD-BD) has a characteristic set of features that can be used both to identify patients and to follow treatment. SIVD-BD patients have clinical, neuropsychological, cerebrospinal fluid (CSF) and imaging features that can be used as biomarkers. No one feature is diagnostic, but a multimodal approach defines the SIVD-BD spectrum disorder. The most important features are large white matter lesions with axonal damage, blood-brain barrier disruption as shown by magnetic resonance imaging and CSF, and neuropsychological evidence of executive dysfunction. We have used these features to create a Binswanger Disease Scale and a probability of SIVD-BD, using a machine-learning algorithm. The patients discussed in this review are derived from published studies. Biomarkers not only aid in early diagnosis before the disease process has progressed too far for treatment, but also can indicate response to treatment. Refining the use of biomarkers will allow dementia treatment to enter the era of precision medicine. This article is part of the Special Issue "Vascular Dementia". © 2017 International Society for Neurochemistry.

  15. NF1 Signal Transduction and Vascular Dysfunction

    Science.gov (United States)

    2015-05-01

    microenvironment that promotes much of the pathology associated with the disease . Moreover we hypothesize that a mechanistic consequence of the loss...obliteration of the normal red pulp architecture. In addition, we found significant peri-aveolar and peri-vascular inflammatory infiltrates in the lung...the mouse model of NF1 disease in the endothelium we proposed and have done experiments investigating the loss of endothelial NF1 in the adult

  16. Role of endovascular treatment in vascular injuries

    International Nuclear Information System (INIS)

    Tahir, M.M.; Haq, T.U.

    2012-01-01

    Objective: To evaluate retrospectively the results, complications and follow-up of patients after endovascular treatment of vascular injuries. Methods: Fifty transcatheter embolisation procedures (TCE) were performed in 46 patients between 1999 and 2008 at the Aga Khan University Hospital, Karachi. Injuries in 14 (30.4%) patients were due to road traffic accident; iatrogenic in 13 (28%); accidental in 6 (13%). Firearms, bomb blasts and earthquake contributed to injuries in 8(17%), 4(8.8%) and 1(2.2%) patients respectively. All patients underwent angiography and had evidence of either active haemorrhage, pseudo-aneurysm, abnormal vascularity or arteriovenous fistula. Follow-up ranged from 1 day to 6 years with mean of 10.5 months. Medical record files, lab results and imaging reports were utilised for the study. Procedure was declared as technically successful when there was cessation of extravasation, occlusion of fistula or exclusion of pseudo-aneurysm in the post-embolisation angiograms. Treatment was deemed clinically successful if there was resolution of the indication for which the procedure was done. Results: Transcatheter embolisation was technically successful in occluding vascular lesions in all 46 (100%) patients. Lesions recurred in 4 (9%) patients who underwent initially successful TCE. These patients were treated effectively with repeated TCE. Three patients died during the same hospital stay and 3 patients died after being discharged from the hospital. All these patients were treated successfully with TCE and had factors other then TCE contributing to their mortality. Conclusion: Transcatheter embolisation for vascular injuries was found to be a satisfactory procedure, with low morbidity and mortality rates. (author)

  17. Vascular access: the impact of ultrasonography

    Science.gov (United States)

    de Almeida, Carlos Eduardo Saldanha

    2016-01-01

    ABSTRACT Vascular punctures are often necessary in critically ill patients. They are secure, but not free of complications. Ultrasonography enhances safety of the procedure by decreasing puncture attempts, complications and costs. This study reviews important publications and the puncture technique using ultrasound, bringing part of the experience of the intensive care unit of the Hospital Israelita Albert Einstein, São Paulo (SP), Brazil, and discussing issues that should be considered in future studies. PMID:28076607

  18. Vascular Dysfunction in Horses with Endocrinopathic Laminitis.

    Directory of Open Access Journals (Sweden)

    Ruth A Morgan

    Full Text Available Endocrinopathic laminitis (EL is a vascular condition of the equine hoof resulting in severe lameness with both welfare and economic implications. EL occurs in association with equine metabolic syndrome and equine Cushing's disease. Vascular dysfunction, most commonly due to endothelial dysfunction, is associated with cardiovascular risk in people with metabolic syndrome and Cushing's syndrome. We tested the hypothesis that horses with EL have vascular, specifically endothelial, dysfunction. Healthy horses (n = 6 and horses with EL (n = 6 destined for euthanasia were recruited. We studied vessels from the hooves (laminar artery, laminar vein and the facial skin (facial skin arteries by small vessel wire myography. The response to vasoconstrictors phenylephrine (10-9-10-5M and 5-hydroxytryptamine (5HT; 10-9-10-5M and the vasodilator acetylcholine (10-9-10-5M was determined. In comparison with healthy controls, acetylcholine-induced relaxation was dramatically reduced in all intact vessels from horses with EL (% relaxation of healthy laminar arteries 323.5 ± 94.1% v EL 90.8 ± 4.4%, P = 0.01, laminar veins 129.4 ± 14.8% v EL 71.2 ± 4.1%, P = 0.005 and facial skin arteries 182.0 ± 40.7% v EL 91.4 ± 4.5%, P = 0.01. In addition, contractile responses to phenylephrine and 5HT were increased in intact laminar veins from horses with EL compared with healthy horses; these differences were endothelium-independent. Sensitivity to phenylephrine was reduced in intact laminar arteries (P = 0.006 and veins (P = 0.009 from horses with EL. Horses with EL exhibit significant vascular dysfunction in laminar vessels and in facial skin arteries. The systemic nature of the abnormalities suggest this dysfunction is associated with the underlying endocrinopathy and not local changes to the hoof.

  19. Role of vascular physiology in hyperthermia

    International Nuclear Information System (INIS)

    Song, C.W.

    1987-01-01

    The rate of blood supply to tumors significantly varies depending on the tumor type, site of tumor growth, and the stage of tumor growth. Even in the same tumor, blood flow is rather heterogeneous. The peripheral area of the tumors where the tissue pressure is relatively low is usually well perfused. Blood flow in the tumors may or may not be greater than that in the adjacent normal tissues. The response of newly formed tumor blood vessels to external stress, such as heat, it different from that in the normal tissues. Blood flow in the experimental rodent tumors initially increases up to twofold of control when heated at relatively low temperatures but tends to decrease when heated at temperatures above 42 0 -43 0 C. On the contrary, blood flow in the skin and muscle of rodents increases up to 20-fold before vascular damage occurs on heating at 43 0 -45 0 C. It thus appears that the vascular beds in tumors are more vulnerable to heat than those in normal tissues. Because of the large increase in blood flow in normal tissue on heating, heat dissipation by blood flow is usually greater in normal tissues than that in tumors during heating. Consequently, the temperature of tumors may rise higher than that in normal tissues. Preferential heating of tumors, however, may not be achieved all the time because the relative blood perfusion in some tumors or in parts of a tumor remains greater than that in the surrounding normal tissues. The intrinsically acidic intratumor environment becomes further acidic on heating owing to an increase in the synthesis of acidic metabolites and retarded removal of them as a result of heat-induced vascular damage. The intratumor environment also becomes hypoxic as a result of retardation of blood flow and vascular damage after heating

  20. Analgesics and sedatives in vascular interventionist radiologic

    International Nuclear Information System (INIS)

    Gregorio, M.A. de; Opta, J.M.; Pulido, J.M.; Encarnacion, C.E.; Arino, I., Fernandez, J.A.; Alfonso, E.R.

    1993-01-01

    Interventionist radiology routinely requires the use of different drugs (analgesics and sedatives) in the course of a procedure. Aside from their therapeutic action, these drugs can produce secondary or undesirable effects, making necessary an in-depth knowledge of them to assure their safe and efficient management. The aim of this work is to provide the vascular interventionist radiologist with additional information on the management of those drugs that contribute to minimizing patient discomfort and pain in interventionist procedures. Author

  1. Robotic vascular resections during Whipple procedure

    OpenAIRE

    Allan, Bassan J.; Novak, Stephanie M.; Hogg, Melissa E.; Zeh, Herbert J.

    2018-01-01

    Indications for resection of pancreatic cancers have evolved to include selected patients with involvement of peri-pancreatic vascular structures. Open Whipple procedures have been the standard approach for patients requiring reconstruction of the portal vein (PV) or superior mesenteric vein (SMV). Recently, high-volume centers are performing minimally invasive Whipple procedures with portovenous resections. Our institution has performed seventy robotic Whipple procedures with concomitant vas...

  2. Endothelial microparticles: Sophisticated vesicles modulating vascular function

    Science.gov (United States)

    Curtis, Anne M; Edelberg, Jay; Jonas, Rebecca; Rogers, Wade T; Moore, Jonni S; Syed, Wajihuddin; Mohler, Emile R

    2015-01-01

    Endothelial microparticles (EMPs) belong to a family of extracellular vesicles that are dynamic, mobile, biological effectors capable of mediating vascular physiology and function. The release of EMPs can impart autocrine and paracrine effects on target cells through surface interaction, cellular fusion, and, possibly, the delivery of intra-vesicular cargo. A greater understanding of the formation, composition, and function of EMPs will broaden our understanding of endothelial communication and may expose new pathways amenable for therapeutic manipulation. PMID:23892447

  3. New molecular probes of vascular inflammation

    International Nuclear Information System (INIS)

    Molecular Cardiovascular Imaging, Westfälische Wilhelms University Münster, Münster, (Germany))" data-affiliation=" (Department of Nuclear Medicine, University Hospital Münster, Münster, and DFG CRC 656 Molecular Cardiovascular Imaging, Westfälische Wilhelms University Münster, Münster, (Germany))" >VRACHIMIS, Alexis; HONOLD, Lisa; Cells in Motion Cluster of Excellence, Westfälische Wilhelms University Münster, Münster, (Germany))" data-affiliation=" (European Institute of Molecular Imaging, Westfälische Wilhelms University Münster, Münster, and DFG EXC 1003 Cells in Motion Cluster of Excellence, Westfälische Wilhelms University Münster, Münster, (Germany))" >FAUST, Andreas; Cells in Motion Cluster of Excellence, Westfälische Wilhelms University Münster, Münster, (Germany))" data-affiliation=" (European Institute of Molecular Imaging, Westfälische Wilhelms University Münster, Münster, and DFG EXC 1003 Cells in Motion Cluster of Excellence, Westfälische Wilhelms University Münster, Münster, (Germany))" >HERMANN, Sven; SCHÄFERS, Michael

    2016-01-01

    New molecular imaging approaches featuring the assessment of inflammatory processes in the vascular wall on top of existing anatomic and functional vessel imaging procedures could emerge as decisive tools for the understanding and prevention of cardiovascular events. In this respect imaging approaches addressing specific molecular and cellular targets in atherosclerosis are of high interest. This review summarizes the rationale and current status of nuclear imaging probes which possess high translational potential.

  4. Early Vascular Ageing - A Concept in Development.

    Science.gov (United States)

    M Nilsson, Peter

    2015-04-01

    Cardiovascular disease (CVD) is a prevalent condition in the elderly, often associated with metabolic disturbance and type 2 diabetes. For a number of years, research dedicated to understand atherosclerosis dominated, and for many good reasons, this pathophysiological process being proximal to the CVD events. In recent years, research has been devoted to an earlier stage of vascular pathology named arteriosclerosis (arterial stiffness) and the new concept of early vascular ageing (EVA), developed by a group of mostly European researchers. This overview describes recent developments in research dedicated to EVA and new emerging aspects found in studies of families at high cardiovascular risk. There are new aspects related to genetics, telomere biology and the role of gut microbiota. However, there is still no unifying definition available of EVA and no direct treatment, but rather only recommendations for conventional cardiovascular risk factor control. New interventions are being developed - not only new antihypertensive drugs, but also new drugs for vascular protection - the selective angiotensin-II (AT2) agonist Compound 21 (C21). Human studies are eagerly awaited. Even new functional food products could have the potential to positively influence cardiometabolic regulation, to be confirmed.

  5. Altos custos financeiros do trauma vascular

    Directory of Open Access Journals (Sweden)

    Ricardo Costa-Val

    Full Text Available OBJETIVO: Demonstrar o custo e impacto financeiro referente à primeira abordagem cirúrgica das lesões vasculares em pacientes admitidos no Hospital João XXIII/FHEMIG, entre os anos de 2004 a 2006. MéTODOS: Trata-se de um estudo com aprovação ética, retrospectivo, de coorte e descritivo realizado a partir da auditoria de contas hospitalares referentes a 70 prontuários catalogados pelo Serviço de Trauma Cardiovascular. RESULTADOS: Cinco (7,14% prontuários foram excluídos por má qualidade técnica. O valor monetário repassado pelo Sistema Único de Saúde e pelo setor privado foram de R$ 103.614,96 (US$ 60.949,97 e de R$ 185.888,21 (US$ 109.346,0, respectivamente, implicando em defasagem potencial de 44%. Houve correlação direta entre custos e topografia anatômica das lesões e exponencial em relação às variáveis hemoderivados e próteses vasculares. CONCLUSÃO: Este estudo corrobora os altos custos do trauma vascular e fortalece a importância da auditoria de contas para as tomadas de decisões médicas.

  6. Pancreatic transplantation: Radiologic evaluation of vascular complications

    International Nuclear Information System (INIS)

    Snider, J.F.; Hunter, D.W.; Kuni, C.C.; Castaneda-Zuniga, W.R.; Letourneau, J.G.

    1991-01-01

    Transplantation of the pancreas is an increasingly common therapeutic option for preventing or delaying complications of type I diabetes mellitus. The authors studied the relative roles of various radiologic examinations in diagnosing vascular complications in these grafts including arterial and venous thrombosis, stenosis, and anastomotic leak (the most common vascular factors that necessitate pancreatectomy of the transplant), as defined with pathologic or arteriographic data. The results of 78 scintigraphic flow studies, 40 abdominal and pelvic computed tomographic (CT) scans, 27 sonograms, and eight color Doppler studies were evaluated in 52 patients who received a total of 27 cadaveric and 26 living-donor grafts over a 12-year period. These results were correlated with the data from 45 gross and microscopic pathologic studies and 37 arteriograms to determine their relative value in enabling detection of graft thrombosis and other vascular complications. Scintigraphy, CT, sonography, and color Doppler were all sensitive in detection of generalized graft abnormalities but lacked specificity in defining the underlying etiologic factors

  7. Pancreatic transplantation: Radiologic evaluation of vascular complications

    Energy Technology Data Exchange (ETDEWEB)

    Snider, J.F.; Hunter, D.W.; Kuni, C.C.; Castaneda-Zuniga, W.R.; Letourneau, J.G. (Univ. of Minnesota Hospital and Clinic, Minneapolis (USA))

    1991-03-01

    Transplantation of the pancreas is an increasingly common therapeutic option for preventing or delaying complications of type I diabetes mellitus. The authors studied the relative roles of various radiologic examinations in diagnosing vascular complications in these grafts including arterial and venous thrombosis, stenosis, and anastomotic leak (the most common vascular factors that necessitate pancreatectomy of the transplant), as defined with pathologic or arteriographic data. The results of 78 scintigraphic flow studies, 40 abdominal and pelvic computed tomographic (CT) scans, 27 sonograms, and eight color Doppler studies were evaluated in 52 patients who received a total of 27 cadaveric and 26 living-donor grafts over a 12-year period. These results were correlated with the data from 45 gross and microscopic pathologic studies and 37 arteriograms to determine their relative value in enabling detection of graft thrombosis and other vascular complications. Scintigraphy, CT, sonography, and color Doppler were all sensitive in detection of generalized graft abnormalities but lacked specificity in defining the underlying etiologic factors.

  8. Arterial vascularization of the pineal gland.

    Science.gov (United States)

    Kahilogullari, Gokmen; Ugur, Hasan Caglar; Comert, Ayhan; Brohi, Recep Ali; Ozgural, Onur; Ozdemir, Mevci; Karahan, Suleyman Tuna

    2013-10-01

    The arterial vascularization of the pineal gland (PG) remains a debatable subject. This study aims to provide detailed information about the arterial vascularization of the PG. Thirty adult human brains were obtained from routine autopsies. Cerebral arteries were separately cannulated and injected with colored latex. The dissections were carried out using a surgical microscope. The diameters of the branches supplying the PG at their origin and vascularization areas of the branches of the arteries were investigated. The main artery of the PG was the lateral pineal artery, and it originated from the posterior circulation. The other arteries included the medial pineal artery from the posterior circulation and the rostral pineal artery mainly from the anterior circulation. Posteromedial choroidal artery was an important artery that branched to the PG. The arterial supply to the PG was studied comprehensively considering the debate and inadequacy of previously published studies on this issue available in the literature. This anatomical knowledge may be helpful for surgical treatment of pathologies of the PG, especially in children who develop more pathology in this region than adults.

  9. VASCULAR REMODELING IN HYPERTENSION: ANGIOGENESIS FEATURES

    Directory of Open Access Journals (Sweden)

    L. A. Haisheva

    2014-07-01

    Full Text Available Aim — cross-sectional study of changes in various segments of the vascular bed in arterial hypertension (AH, defining the role of inducers and inhibitors of angiogenesis in these processes.Materials and methods. The study included 99 patients with arterial hypertension of I–II degree, average age of 63.2 ± 2.6 years, diseaseduration 9.2 ± 7.2 years.Results. It was found that patients with arterial hypertension have disorders in all segments of vascular bed: endothelial dysfunction (highvWF, microcirculatory disorders, and increased pulse wave velocity (PWV of elastic-type vessels. The level of angioginesis factors doesnot depend on such parameters as gender, age, body mass index. Smoking and duration of hypertension influence on vascular endothelialgrowth factor raise and endostatin levels are higher in patients with family history of cardiovascular diseases. Duration of disease is directlycorrelated with microcirculatory disorders and the PWV, correlation between microcirculatory disorders and pulse wave velocity indicatetheir common processes.

  10. Amplatzer vascular plugs in congenital cardiovascular malformations

    International Nuclear Information System (INIS)

    Barwad, Parag; Ramakrishnan, Sivasubramanian; Kothari, Shyam S; Saxena, Anita; Gupta, Saurabh K; Juneja, Rajnish; Gulati, Gurpreet Singh; Jagia, Priya; Sharma, Sanjiv

    2013-01-01

    Amplatzer vascular plugs (AVPs) are devices ideally suited to close medium-to-large vascular communications. There is limited published literature regarding the utility of AVPs in congenital cardiovascular malformations (CCVMs). To describe the use of AVPs in different CCVMs and to evaluate their safety and efficacy. All patients who required an AVP for the closure of CCVM were included in this retrospective review of our catheterization laboratory data. The efficacy and safety of AVPs are reported. A total of 39 AVPs were implanted in 31 patients. Thirteen (33%) were AVP type I and 23 (59%) were AVP type II. AVP type III were implanted in two patients and type IV in one patient. The major indications for their use included closure of pulmonary arteriovenous malformation (AVM) (n = 7), aortopulmonary collaterals (n = 7), closure of a patent Blalock-Taussig shunt (n = 5), systemic AVM (n = 5), coronary AVM (n = 4), patent ductus arteriosus (PDA) (n = 3), pulmonary artery aneurysms (n = 3), and venovenous collaterals (n = 2). Deployment of the AVP was done predominantly via the 5 – 7F Judkin's right coronary guide catheter. Overall 92% of the AVPs could be successfully deployed and resulted in occlusion of the target vessel in all cases, within 10 minutes. No procedure-related or access site complication occurred. AVPs are versatile, easy to use, and effective devices to occlude the vascular communications in a variety of settings. AVP II is especially useful in the closure of tubular structures with a high flow

  11. Vascular development in the vertebrate pancreas

    Science.gov (United States)

    Azizoglu, D. Berfin; Chong, Diana C.; Villasenor, Alethia; Magenheim, Judith; Barry, David M.; Lee, Simon; Marty-Santos, Leilani; Fu, Stephen; Dor, Yuval; Cleaver, Ondine

    2016-01-01

    The vertebrate pancreas is comprised of a highly branched tubular epithelium, which is intimately associated with an extensive and specialized vasculature. While we know a great deal about basic vascular anatomy of the adult pancreas, as well as islet capillaries, surprisingly little is known about the ontogeny of its blood vessels. Here, we analyze development of the pancreatic vasculature in the mouse embryo. We show that pancreatic epithelial branches intercalate with the fine capillary plexus of the surrounding pancreatic mesenchyme. Endothelial cells (ECs) within this mesenchyme are heterogeneous from the onset of organogenesis. Pancreatic arteries take shape before veins, in a manner analogous to early embryonic vessels. The main central artery forms during mid-gestation, as a result of vessel coalescence and remodeling of a vascular plexus. In addition, we show that vessels in the forming pancreas display a predictable architecture that is dependent on VEGF signaling. Over-expression of VEGF disrupts vascular patterning and arteriovenous differentiation within the developing pancreas. This study constitutes a first-time cellular and molecular characterization of pancreatic blood vessels, as they coordinately grow along with the pancreatic epithelium. PMID:27789228

  12. Vascularized nerve grafts: an experimental study.

    Science.gov (United States)

    Donzelli, Renato; Capone, Crescenzo; Sgulò, Francesco Giovanni; Mariniello, Giuseppe; Maiuri, Francesco

    2016-08-01

    The aim of this study is to define an experimental model in order to promote the functional recovery of the nerves using grafts with vascular support (Vascular Nerve Grafts - VNG). The aim of this study is to define, on an experimental model in normal recipient bed, whether the functional recovery with VNG is superior to that obtained non-vascularized graft (NNG). Twenty male rabbits, which underwent dissection of sciatic nerve, were later treated by reinnervation through an autograft. In 10 animals the reconstruction of sciatic nerve was realized with VNG; in 10 control animals the reconstruction of sciatic nerve was realized with NNG. The VNG group showed a better axonal organization and a significantly higher number of regenerated axons in the early phases (after 30 days) than the NNG group, whereas the difference in the axonal number at day 90 was less significant; besides, the axon diameter and the myelin thickness were not significantly improved by VNG group. Our data suggests that the use of VNG leads to a faster regeneration process and a better functional recovery, although the final results are comparable to those of the NNG. VNG improve the quality of the axonal regeneration (axonal diameter and Schwann cells), although the increase in the axonal number is not significant and does not improve the long-term functional outcome.

  13. Vascular nitric oxide: Beyond eNOS

    Directory of Open Access Journals (Sweden)

    Yingzi Zhao

    2015-10-01

    Full Text Available As the first discovered gaseous signaling molecule, nitric oxide (NO affects a number of cellular processes, including those involving vascular cells. This brief review summarizes the contribution of NO to the regulation of vascular tone and its sources in the blood vessel wall. NO regulates the degree of contraction of vascular smooth muscle cells mainly by stimulating soluble guanylyl cyclase (sGC to produce cyclic guanosine monophosphate (cGMP, although cGMP-independent signaling [S-nitrosylation of target proteins, activation of sarco/endoplasmic reticulum calcium ATPase (SERCA or production of cyclic inosine monophosphate (cIMP] also can be involved. In the blood vessel wall, NO is produced mainly from l-arginine by the enzyme endothelial nitric oxide synthase (eNOS but it can also be released non-enzymatically from S-nitrosothiols or from nitrate/nitrite. Dysfunction in the production and/or the bioavailability of NO characterizes endothelial dysfunction, which is associated with cardiovascular diseases such as hypertension and atherosclerosis.

  14. Vascular development in the vertebrate pancreas.

    Science.gov (United States)

    Azizoglu, D Berfin; Chong, Diana C; Villasenor, Alethia; Magenheim, Judith; Barry, David M; Lee, Simon; Marty-Santos, Leilani; Fu, Stephen; Dor, Yuval; Cleaver, Ondine

    2016-12-01

    The vertebrate pancreas is comprised of a highly branched tubular epithelium, which is intimately associated with an extensive and specialized vasculature. While we know a great deal about basic vascular anatomy of the adult pancreas, as well as islet capillaries, surprisingly little is known about the ontogeny of its blood vessels. Here, we analyze development of the pancreatic vasculature in the mouse embryo. We show that pancreatic epithelial branches intercalate with the fine capillary plexus of the surrounding pancreatic mesenchyme. Endothelial cells (ECs) within this mesenchyme are heterogeneous from the onset of organogenesis. Pancreatic arteries take shape before veins, in a manner analogous to early embryonic vessels. The main central artery forms during mid-gestation, as a result of vessel coalescence and remodeling of a vascular plexus. In addition, we show that vessels in the forming pancreas display a predictable architecture that is dependent on VEGF signaling. Over-expression of VEGF disrupts vascular patterning and arteriovenous differentiation within the developing pancreas. This study constitutes a first-time in-depth cellular and molecular characterization of pancreatic blood vessels, as they coordinately grow along with the pancreatic epithelium. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Electrotonic vascular signal conduction and nephron synchronization

    DEFF Research Database (Denmark)

    Marsh, D.J.; Toma, I.; Sosnovtseva, Olga

    2009-01-01

    Marsh DJ, Toma I, Sosnovtseva OV, Peti-Peterdi J, Holstein-Rathlou NH. Electrotonic vascular signal conduction and nephron synchronization. Am J Physiol Renal Physiol 296: F751-F761, 2009. First published December 30, 2008; doi:10.1152/ajprenal.90669.2008.-Tubuloglomerular feedback (TGF) and the ......Marsh DJ, Toma I, Sosnovtseva OV, Peti-Peterdi J, Holstein-Rathlou NH. Electrotonic vascular signal conduction and nephron synchronization. Am J Physiol Renal Physiol 296: F751-F761, 2009. First published December 30, 2008; doi:10.1152/ajprenal.90669.2008.-Tubuloglomerular feedback (TGF......) and the myogenic mechanism control afferent arteriolar diameter in each nephron and regulate blood flow. Both mechanisms generate self-sustained oscillations, the oscillations interact, TGF modulates the frequency and amplitude of the myogenic oscillation, and the oscillations synchronize; a 5: 1 frequency ratio...... is the most frequent. TGF oscillations synchronize in nephron pairs supplied from a common cortical radial artery, as do myogenic oscillations. We propose that electrotonic vascular signal propagation from one juxtaglomerular apparatus interacts with similar signals from other nephrons to produce...

  16. Local above-ground persistence of vascular plants : Life-history trade-offs and environmental constraints

    NARCIS (Netherlands)

    Ozinga, Wim A.; Hennekens, Stephan M.; Schaminee, Joop H. J.; Smits, Nina A. C.; Bekker, Renee M.; Roemermann, Christine; Klimes, Leos; Bakker, Jan P.; van Groenendael, Jan M.

    Questions: 1. Which plant traits and habitat characteristics best explain local above-ground persistence of vascular plant species and 2. Is there a trade-off between local above-ground persistence and the ability for seed dispersal and below-ground persistence in the soil seed bank? Locations: 845

  17. Role of Experience With Preventive Medication and Personal Risk Attitude in Non-Attendance at Triple Vascular Screening

    DEFF Research Database (Denmark)

    Hansen, Tina B.; Lindholt, Jes S.; Søgaard, Rikke

    2018-01-01

    , and hypertension in the Viborg Vascular (VIVA) screening trial. Data on socio-demographic and socio-economic characteristics, diagnoses, and use of preventive medication were extracted from national registries. A proxy for personal risk attitude was constructed. Logistic regression was used to estimate odds ratios...

  18. Vegetative and hemodynamic responses to stress in adolescents with constitutional-exogenous obesity and vascular dystonia of hypertensive type

    OpenAIRE

    Larina, N.

    2011-01-01

    We studied the characteristics of central hemodynamics and autonomic responses to cold and psycho-emotional test in adolescents with obesity and vascular dystonia of hypertensive type. Various options for the autonomic responses accompanied by changes in central hemodynamics as a function of body weight have been identified.

  19. Plasma protein corona modulates the vascular wall interaction of drug carriers in a material and donor specific manner.

    Directory of Open Access Journals (Sweden)

    Daniel J Sobczynski

    Full Text Available The nanoscale plasma protein interaction with intravenously injected particulate carrier systems is known to modulate their organ distribution and clearance from the bloodstream. However, the role of this plasma protein interaction in prescribing the adhesion of carriers to the vascular wall remains relatively unknown. Here, we show that the adhesion of vascular-targeted poly(lactide-co-glycolic-acid (PLGA spheres to endothelial cells is significantly inhibited in human blood flow, with up to 90% reduction in adhesion observed relative to adhesion in simple buffer flow, depending on the particle size and the magnitude and pattern of blood flow. This reduced PLGA adhesion in blood flow is linked to the adsorption of certain high molecular weight plasma proteins on PLGA and is donor specific, where large reductions in particle adhesion in blood flow (>80% relative to buffer is seen with ∼60% of unique donor bloods while others exhibit moderate to no reductions. The depletion of high molecular weight immunoglobulins from plasma is shown to successfully restore PLGA vascular wall adhesion. The observed plasma protein effect on PLGA is likely due to material characteristics since the effect is not replicated with polystyrene or silica spheres. These particles effectively adhere to the endothelium at a higher level in blood over buffer flow. Overall, understanding how distinct plasma proteins modulate the vascular wall interaction of vascular-targeted carriers of different material characteristics would allow for the design of highly functional delivery vehicles for the treatment of many serious human diseases.

  20. Clinical Correlates of Hachinski Ischemic Score and Vascular Factors in Cognitive Function of Elderly

    Directory of Open Access Journals (Sweden)

    Youn Ho Kim

    2014-01-01

    Full Text Available The aim of this study is to investigate the relationship between Hachinski ischemic score (HIS and vascular factors as well as between HIS and the cognitive function in elderly community. Demographic characteristics, such as sex, age, education, history of drinking and smoking, family history of dementia and stroke, diabetes mellitus, hypertension, hyperlipidemia, cardiovascular disease, stroke, and dementia, were surveyed. Neurological examination was administered to every subject and HIS was checked by a neurologist. From a total of 392 participants aged 65 and over in a rural community, 348 completed the survey and were finally enrolled. Among the vascular factors, history of hypertension (P=0.008, history of stroke (P<0.001, family history of dementia (P=0.01, and history of cardiac diseases (P=0.012 showed a significant relationship with HIS. In the cognitive function tests, both Korean version of the Mini-Mental State Examination and the Clinical Dementia Rating (Global and Sum of Boxes had a significant relationship with HIS. Our study suggested HIS may have an association with some vascular factors and cognitive scales in community dwelling elderly. In this study, the HIS seemed to contribute to the evaluation of the quantity of vascular factors and to the prediction of status of cognitive function.

  1. MR imaging of avascular scaphoid nonunion before and after vascularized bone grafting

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Suzanne E.; Tschering-Vogel, Dechen; Martin, Matthias [University Hospital of Bern, Inselspital, Department of Radiology, Bern (Switzerland); Steinbach, Lynne S. [University of California San Francisco, Department of Radiology, San Francisco, California (United States); Nagy, Ladislav [University Hospital of Bern, Inselspital, Department of Orthopedic Surgery, Bern (Switzerland)

    2005-06-01

    To investigate the magnetic resonance (MR) imaging appearances of chronic nonunion of the scaphoid with proximal pole avascular necrosis before and after insertion of a vascularized bone graft, using computed tomography (CT) as the imaging gold standard. A retrospective study was performed involving MR imaging (n=26), CT scans (n=37) and radiographs (n=52) of 13 men (mean age 29 years, age range 20-38 years) with avascular scaphoid nonunion. Avascular necrosis of the scaphoid proximal pole was confirmed intraoperatively (n=13). MR images were acquired preoperatively and following placement of a vascularized bone graft. Scaphoid MR signal characteristics were assessed for evidence of vascular bone graft incorporation and revascularization of the bone marrow of the proximal pole of the scaphoid and compared with the gold standard of CT. Surgical and clinical notes were reviewed with a minimum 3 year imaging and clinical follow-up in all patients. Graft incorporation with revascularization of the proximal pole of the scaphoid was documented in 9 patients (69%). Graft failure with persistent pseudoarthrosis and avascular necrosis of the scaphoid was seen in 4 patients (31%). MR imaging is useful to determine whether vascularized bone graft incorporation and revascularization of the proximal pole of the scaphoid has occurred in the setting of avascular scaphoid nonunion. (orig.)

  2. Prominent Vascularization Capacity of Mesenchymal Stem Cells in Collagen-Gold Nanocomposites.

    Science.gov (United States)

    Hsieh, Shu-Chen; Chen, Hui-Jye; Hsu, Shan-Hui; Yang, Yi-Chin; Tang, Cheng-Ming; Chu, Mei-Yun; Lin, Pei-Ying; Fu, Ru-Huei; Kung, Mei-Lang; Chen, Yun-Wen; Yeh, Bi-Wen; Hung, Huey-Shan

    2016-10-26

    The ideal characteristics of surface modification on the vascular graft for clinical application would be with excellent hemocompatibility, endothelialization capacity, and antirestenosis ability. Here, Fourier transform infrared spectroscopy (FTIR), surface enhanced Raman spectroscopy (SERS), atomic force microscopy (AFM), contact angle (θ) measurement, and thermogravimetric analysis (TGA) were used to evaluate the chemical and mechanical properties of collagen-gold nanocomposites (collagen+Au) with 17.4, 43.5, and 174 ppm of Au and suggested that the collagen+Au with 43.5 ppm of Au had better biomechanical properties and thermal stability than pure collagen. Besides, stromal-derived factor-1α (SDF-1α) at 50 ng/mL promoted the migration of mesenchymal stem cells (MSCs) on collagen+Au material through the α5β3 integrin/endothelial oxide synthase (eNOS)/metalloproteinase (MMP) signaling pathway which can be abolished by the knockdown of vascular endothelial growth factor (VEGF). The potentiality of collagen+Au with MSCs for vascular regeneration was evaluated by our in vivo rat model system. Artery tissues isolated from an implanted collagen+Au-coated catheter with MSCs expressed substantial CD-31 and α-SMA, displayed higher antifibrotic ability, antithrombotic activity, as well as anti-inflammatory response than all other materials. Our results indicated that the implantation of collagen+Au-coated catheters with MSCs could be a promising strategy for vascular regeneration.

  3. MR imaging of avascular scaphoid nonunion before and after vascularized bone grafting

    International Nuclear Information System (INIS)

    Anderson, Suzanne E.; Tschering-Vogel, Dechen; Martin, Matthias; Steinbach, Lynne S.; Nagy, Ladislav

    2005-01-01

    To investigate the magnetic resonance (MR) imaging appearances of chronic nonunion of the scaphoid with proximal pole avascular necrosis before and after insertion of a vascularized bone graft, using computed tomography (CT) as the imaging gold standard. A retrospective study was performed involving MR imaging (n=26), CT scans (n=37) and radiographs (n=52) of 13 men (mean age 29 years, age range 20-38 years) with avascular scaphoid nonunion. Avascular necrosis of the scaphoid proximal pole was confirmed intraoperatively (n=13). MR images were acquired preoperatively and following placement of a vascularized bone graft. Scaphoid MR signal characteristics were assessed for evidence of vascular bone graft incorporation and revascularization of the bone marrow of the proximal pole of the scaphoid and compared with the gold standard of CT. Surgical and clinical notes were reviewed with a minimum 3 year imaging and clinical follow-up in all patients. Graft incorporation with revascularization of the proximal pole of the scaphoid was documented in 9 patients (69%). Graft failure with persistent pseudoarthrosis and avascular necrosis of the scaphoid was seen in 4 patients (31%). MR imaging is useful to determine whether vascularized bone graft incorporation and revascularization of the proximal pole of the scaphoid has occurred in the setting of avascular scaphoid nonunion. (orig.)

  4. Expression of Vascular Endothelial Growth Factor Receptors in Benign Vascular Lesions of the Orbit: A Case Series.

    Science.gov (United States)

    Atchison, Elizabeth A; Garrity, James A; Castillo, Francisco; Engman, Steven J; Couch, Steven M; Salomão, Diva R

    2016-01-01

    Vascular lesions of the orbit, although not malignant, can cause morbidity because of their location near critical structures in the orbit. For the same reason, they can be challenging to remove surgically. Anti-vascular endothelial growth factor (VEGF) drugs are increasingly being used to treat diseases with prominent angiogenesis. Our study aimed to determine to what extent VEGF receptors and their subtypes are expressed on selected vascular lesions of the orbit. Retrospective case series of all orbital vascular lesions removed by one of the authors (JAG) at the Mayo Clinic. A total of 52 patients who underwent removal of vascular orbital lesions. The pathology specimens from the patients were retrieved, their pathologic diagnosis was confirmed, demographic and clinical information were gathered, and sections from vascular tumors were stained with vascular endothelial growth factor receptor (VEGFR), vascular endothelial growth factor receptor type 1 (VEGFR1), vascular endothelial growth factor receptor type 2 (VEGFR2), and vascular endothelial growth factor receptor type 3 (VEGFR3). The existence and pattern of staining with VEGF and its subtypes on these lesions. There were 28 specimens of venous malformations, 4 capillary hemangiomas, 7 lymphatic malformations, and 6 lymphaticovenous malformations. All samples stained with VEGF, 55% stained with VEGFR1, 98% stained with VEGFR2, and 96% stained with VEGFR3. Most (94%) of the VEGFR2 staining was diffuse. Most orbital vascular lesions express VEGF receptors, which may suggest a future target for nonsurgical treatment. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  5. Diffuse and vascular hepatic diseases; Diffuse und vaskulaere Lebererkrankungen

    Energy Technology Data Exchange (ETDEWEB)

    Kreimeyer, S.; Grenacher, L. [Universitaetsklinikum Heidelberg, Abteilung Diagnostische und Interventionelle Radiologie, Heidelberg (Germany)

    2011-08-15

    In addition to focal liver lesions, diffuse and vascular disorders of the liver represent a wide spectrum of liver diseases which are from the radiological point of view often difficult or nearly impossible to diagnose. Classical diagnostic methods are computed tomography and magnetic resonance imaging in addition to ultrasound. Diffuse parenchymal damage caused by diseases of various etiologies is therefore difficult to evaluate because it often lacks characteristic morphological features. For hepatic steatosis, hemochromatosis/siderosis as an example of a diffuse storage disease and sarcoidosis and candidiasis as infectious/inflammatory diseases, an image-based diagnosis is appropriate in some cases. For most diffuse liver diseases, however only nonspecific changes are visualized. Vascular pathologies of the liver, such as the Budd-Chiari syndrome and portal vein thrombosis, however, can usually be diagnosed very clearly using radiology and there is also a very effective interventional radiological treatment. Chronic diseases very often culminate in liver cirrhosis which is highly associated with an increased risk of liver cancer. (orig.) [German] Neben den fokalen Leberlaesionen stellen diffuse und vaskulaere Lebererkrankungen ein weites Spektrum an Erkrankungen der Leber dar, die radiologisch oft schwer oder gar nicht diagnostizierbar sind. Klassische diagnostische Verfahren sind dabei neben dem Ultraschall die Computertomographie und die Magnetresonanztomographie. Diffuse Parenchymschaeden, bedingt durch Erkrankungen unterschiedlichster Aetiologie, sind deshalb schwierig evaluierbar, weil haeufig charakteristische bildmorphologische Merkmale fehlen. Die Steatosis hepatis, die Haemochromatose/Siderose als Beispiel der Speicherkrankheiten sowie die Sarkoidose und die Candidose als infektioes-entzuendliche Erkrankungen sind einer bildbasierten Diagnosestellung z. T. zugaenglich, bei den meisten diffusen Lebererkrankungen jedoch zeigen sich lediglich unspezifische

  6. Unexpected diagnosis of superficial neurofibroma in a lesion with imaging features of a vascular malformation

    Energy Technology Data Exchange (ETDEWEB)

    O' Keefe, Patrick; Reid, Janet; Morrison, Stuart [Cleveland Clinic Foundation, Department of Radiology, Cleveland, OH (United States); Vidimos, Allison [Cleveland Clinic Foundation, Department of Dermatology, Cleveland, OH (United States); DiFiore, John [Cleveland Clinic Foundation, Department of Pediatric Surgery, Cleveland, OH (United States)

    2005-12-01

    Plexiform neurofibroma is a pathognomonic, often disabling feature of neurofibromatosis type I. Although the target-like appearance of deep plexiform neurofibroma on T2-weighted MRI has been well-described, a second superficial form of plexiform neurofibroma has differing imaging features. We report a 15-year-old boy who presented with multiple cutaneous lesions exhibiting clinical and imaging characteristics of a venolymphatic malformation. These lesions were histologically proved to represent superficial plexiform neurofibromas. We wish to emphasize the unique MR findings of superficial plexiform neurofibromas; these findings are different from the imaging characteristics of the deep form and can be confused with a low-flow vascular malformation. (orig.)

  7. Retinal vascular segmentation using superpixel-based line operator and its application to vascular topology estimation.

    Science.gov (United States)

    Na, Tong; Xie, Jianyang; Zhao, Yitian; Zhao, Yifan; Liu, Yue; Wang, Yongtian; Liu, Jiang

    2018-05-09

    Automatic methods of analyzing of retinal vascular networks, such as retinal blood vessel detection, vascular network topology estimation, and arteries/veins classification are of great assistance to the ophthalmologist in terms of diagnosis and treatment of a wide spectrum of diseases. We propose a new framework for precisely segmenting retinal vasculatures, constructing retinal vascular network topology, and separating the arteries and veins. A nonlocal total variation inspired Retinex model is employed to remove the image intensity inhomogeneities and relatively poor contrast. For better generalizability and segmentation performance, a superpixel-based line operator is proposed as to distinguish between lines and the edges, thus allowing more tolerance in the position of the respective contours. The concept of dominant sets clustering is adopted to estimate retinal vessel topology and classify the vessel network into arteries and veins. The proposed segmentation method yields competitive results on three public data sets (STARE, DRIVE, and IOSTAR), and it has superior performance when compared with unsupervised segmentation methods, with accuracy of 0.954, 0.957, and 0.964, respectively. The topology estimation approach has been applied to five public databases (DRIVE,STARE, INSPIRE, IOSTAR, and VICAVR) and achieved high accuracy of 0.830, 0.910, 0.915, 0.928, and 0.889, respectively. The accuracies of arteries/veins classification based on the estimated vascular topology on three public databases (INSPIRE, DRIVE and VICAVR) are 0.90.9, 0.910, and 0.907, respectively. The experimental results show that the proposed framework has effectively addressed crossover problem, a bottleneck issue in segmentation and vascular topology reconstruction. The vascular topology information significantly improves the accuracy on arteries/veins classification. © 2018 American Association of Physicists in Medicine.

  8. Accelerated Vascular Aging as a Paradigm for Hypertensive Vascular Disease: Prevention and Therapy.

    Science.gov (United States)

    Barton, Matthias; Husmann, Marc; Meyer, Matthias R

    2016-05-01

    Aging is considered the most important nonmodifiable risk factor for cardiovascular disease and death after age 28 years. Because of demographic changes the world population is expected to increase to 9 billion by the year 2050 and up to 12 billion by 2100, with several-fold increases among those 65 years of age and older. Healthy aging and prevention of aging-related diseases and associated health costs have become part of political agendas of governments around the world. Atherosclerotic vascular burden increases with age; accordingly, patients with progeria (premature aging) syndromes die from myocardial infarctions or stroke as teenagers or young adults. The incidence and prevalence of arterial hypertension also increases with age. Arterial hypertension-like diabetes and chronic renal failure-shares numerous pathologies and underlying mechanisms with the vascular aging process. In this article, we review how arterial hypertension resembles premature vascular aging, including the mechanisms by which arterial hypertension (as well as other risk factors such as diabetes mellitus, dyslipidemia, or chronic renal failure) accelerates the vascular aging process. We will also address the importance of cardiovascular risk factor control-including antihypertensive therapy-as a powerful intervention to interfere with premature vascular aging to reduce the age-associated prevalence of diseases such as myocardial infarction, heart failure, hypertensive nephropathy, and vascular dementia due to cerebrovascular disease. Finally, we will discuss the implementation of endothelial therapy, which aims at active patient participation to improve primary and secondary prevention of cardiovascular disease. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  9. Hemodynamic characteristics of early stage hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Kudo, Masatoshi; Tomita, Shusuke; Tochio, Hitoshi

    1992-01-01

    Hemodynamic characteristics were studied by using in vivo vascular imaging techniques in 17 resected early stage hepatocellular carcinoma (e-HCC) by comparing them with 49 resected advanced HCCs (ad-HCC) less than 3 cm in diameter. In this study, e-HCC was defined as the nodule being uniformly composed of well-differentiated HCC or adenomatous hyperplastic nodule containing well-differentiated HCC foci within the nodule. In vivo vascular imaging techniques are as follows; US angiography with intraarterial CO 2 microbubbles were performed to assess the tumor arterial vascularity, and CT during arterial portography (CTAP) was performed to assess the portal perfusion within the nodule. Of 17 e-HCC nodules 5 were hypervascular, 5 were isovascular, 4 were hypovascular, and 3 were vascular spot in hypovascular pattern in contrast to 49 ad-HCC nodules, 43 of which were hypervascular and 6 were isovascular. Of 14 e-HCCs, 9 nodules showed perfusion defect and 5 did not on CTAP, whereas all 37 ad-HCCs on which CTAP was performed, showed perfusion defect. Forty-one percent (7/17) of e-HCC showed fatty metamorphosis in contrast to 8% (4/49) of ad-HCC. In conclusion, hemodynamic characteristics of e-HCC are summarized as follows. (1) Arterial tumor neovascularization is relatively low. (2) Portal perfusion is present in some of e-HCC cases. (3) Hypoperfusion state both from arterial and portal supply is present in some of e-HCC cases. (4) Vascular spot in hypovascular pattern is characteristic arterial pattern in AH containing HCC foci. (5) Fatty metamorphosis may be related with hypoperfusion state of the nodule in e-HCC. (author)

  10. Revascularization of diaphyseal bone segments by vascular bundle implantation.

    Science.gov (United States)

    Nagi, O N

    2005-11-01

    Vascularized bone transfer is an effective, established treatment for avascular necrosis and atrophic or infected nonunions. However, limited donor sites and technical difficulty limit its application. Vascular bundle transplantation may provide an alternative. However, even if vascular ingrowth is presumed to occur in such situations, its extent in aiding revascularization for ultimate graft incorporation is not well understood. A rabbit tibia model was used to study and compare vascularized, segmental, diaphyseal, nonvascularized conventional, and vascular bundle-implanted grafts with a combination of angiographic, radiographic, histopathologic, and bone scanning techniques. Complete graft incorporation in conventional grafts was observed at 6 months, whereas it was 8 to 12 weeks with either of the vascularized grafts. The pattern of radionuclide uptake and the duration of graft incorporation between vascular segmental bone grafts (with intact endosteal blood supply) and vascular bundle-implanted segmental grafts were similar. A vascular bundle implanted in the recipient bone was found to anastomose extensively with the intraosseous circulation at 6 weeks. Effective revascularization of bone could be seen when a simple vascular bundle was introduced into a segment of bone deprived of its normal blood supply. This simple technique offers promise for improvement of bone graft survival in clinical circumstances.

  11. Vascular Variations Associated with Intracranial Aneurysms.

    Science.gov (United States)

    Orakdogen, Metin; Emon, Selin Tural; Somay, Hakan; Engin, Taner; Is, Merih; Hakan, Tayfun

    2017-01-01

    To investigate the vascular variations in patients with intracranial aneurysm in circle of Willis. We used the data on 128 consecutive intracranial aneurysm cases. Cerebral angiography images were analyzed retrospectively. Arteries were grouped as anterior cerebral arterial system (ACS), posterior cerebral arterial system (PCS) and middle cerebral arterial system (MCS) for grouping vascular variations. Lateralization, being single/multiple, gender; and also any connection with accompanying aneurysms" number, localization, dimension, whether bleeding/incidental aneurysm has been inspected. Variations were demonstrated in 57.8% of the cases. The most common variation was A1 variation (34.4%). The rate of variations was 36.7%, 24.2% and 10.2% respectively in ACS, PCS and MCS. MCS variations were significantly higher in males. Anterior communicating artery (ACoA) aneurysm observance rates were significantly higher and posterior communicating artery (PCoA) aneurysm and middle cerebral artery (MCA) aneurysm observance rates were significantly lower when compared to "no ACS variation detected" cases. In "PCS variation detected" cases, PCoA aneurysm observance rates and coexistence of multiple variations were significantly higher. The rate of vascular variations in patients with aneurysms was 57.8%. Arterial hypoplasia and aplasia were the most common variations. ACS was the most common region that variations were located in; they were mostly detected on the right side. Coexistence of ACoA aneurysm was higher than PCoA and MCA aneurysms. In the PCS variations group, PCoA aneurysms were the most common aneurysms that accompanying the variation and multiple variations were more common than in the other two groups. The variations in MCS were most common in males.

  12. T cells in vascular inflammatory diseases

    Directory of Open Access Journals (Sweden)

    Lucas L Lintermans

    2014-10-01

    Full Text Available Inflammation of the human vasculature is a manifestation of many different diseases ranging from systemic autoimmune diseases to chronic inflammatory diseases, in which multiple types of immune cells are involved. For both autoimmune diseases and chronic inflammatory diseases several observations support a key role for T lymphocytes in these disease pathologies, but the underlying mechanisms are poorly understood. Previous studies in several autoimmune diseases have demonstrated a significant role for a specific subset of CD4+ T cells termed effector memory T cells. This expanded population of effector memory T cells may contribute to tissue injury and disease progression. These cells exert multiple pro-inflammatory functions through the release of effector cytokines. Many of these cytokines have been detected in the inflammatory lesions and participate in the vasculitic reaction, contributing to recruitment of macrophages, neutrophils, dendritic cells, NK cells, B cells and T cells. In addition, functional impairment of regulatory T cells paralyzes anti-inflammatory effects in vasculitic disorders. Interestingly, activation of effector memory T cells in uniquely dependent on the voltage-gated Kv1.3 potassium channel providing an anchor for specific drug targeting. In this review, we focus on the CD4+ T cells in the context of vascular inflammation and describe the evidence supporting the role of different T cell subsets in vascular inflammation. Selective targeting of pathogenic effector memory T cells might enable a more tailored therapeutic approach that avoids unwanted adverse side effects of generalized immunosuppression by modulating the effector functions of T cell responses to inhibit the development of vascular inflammation.

  13. Extraglandular and intraglandular vascularization of canine prostate.

    Science.gov (United States)

    Stefanov, Miroslav

    2004-03-01

    The literature on the vascularization of the canine prostate is reviewed and the clinical significance of prostate morphology is described. Scanning Electron Microscopy (SEM), combined with improved corrosion casting methods, reveal new morphological details that promise better diagnostics and treatment but also require expansion of clinical nomenclature. A proposal is made for including two previously unnamed veins in Nomina Anatomica Veterinaria (NAV). The canine prostate has two lobes with independent vascularization. Each lobe is supplied through the left and right a. prostatica, respectively. The a. prostatica sprouts three small vessels (cranial, middle, and caudal) towards the prostate gland. A. prostatica is a small-size artery whose wall structure is similar to the arteries of the muscular type. V. prostatica is a small-size valved vein. The canine prostate has capsular, parenchymal, and urethral vascular zones. The surface vessels of the capsule are predominantly veins and the diameter of arterial vessels is larger than that of the veins. The trabecular vessels are of two types: direct and branched. The prostate parenchyma is supplied by branches of the trabecular vessels. The periacinary capillaries are fenestrated and form a net in a circular pattern. The processes of the myoepithelial cells embrace both the acins and the periacinar capillaries. In the prostate ductal system. there are spermatozoa. The prostatic part of the urethra is supplied by an independent branch of a. prostatica. The prostatic urethral part is drained by v. prostatica, the vein of the urethral bulb and the ventral prostate veins. M. urethralis begins as early as the urethral prostatic part. The greater part of the white muscle fibers in m. urethralis suggest an enhanced anaerobic metabolism. Copyright 2004 Wiley-Liss, Inc.

  14. Management of bleeding in vascular surgery.

    Science.gov (United States)

    Chee, Y E; Liu, S E; Irwin, M G

    2016-09-01

    Management of acute coagulopathy and blood loss during major vascular procedures poses a significant haemostatic challenge to anaesthetists. The acute coagulopathy is multifactorial in origin with tissue injury and hypotension as the precipitating factors, followed by dilution, hypothermia, acidemia, hyperfibrinolysis and systemic inflammatory response, all acting as a self-perpetuating spiral of events. The problem is confounded by the high prevalence of antithrombotic agent use in these patients and intraoperative heparin administration. Trials specifically examining bleeding management in vascular surgery are lacking, and much of the literature and guidelines are derived from studies on patients with trauma. In general, it is recommended to adopt permissive hypotension with a restrictive fluid strategy, using a combination of crystalloid and colloid solutions up to one litre during the initial resuscitation, after which blood products should be administered. A restrictive transfusion trigger for red cells remains the mainstay of treatment except for the high-risk patients, where the trigger should be individualized. Transfusion of blood components should be initiated by clinical evidence of coagulopathy such as diffuse microvascular bleeding, and then guided by either laboratory or point-of-care coagulation testing. Prophylactic antifibrinolytic use is recommended for all surgery where excessive bleeding is anticipated. Fibrinogen and prothrombin complex concentrates administration are recommended during massive transfusion, whereas rFVIIa should be reserved until all means have failed. While debates over the ideal resuscitative strategy continue, the approach to vascular haemostasis should be scientific, rational, and structured. As far as possible, therapy should be monitored and goal directed. © The Author 2016. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. BOLD Granger causality reflects vascular anatomy.

    Directory of Open Access Journals (Sweden)

    J Taylor Webb

    Full Text Available A number of studies have tried to exploit subtle phase differences in BOLD time series to resolve the order of sequential activation of brain regions, or more generally the ability of signal in one region to predict subsequent signal in another region. More recently, such lag-based measures have been applied to investigate directed functional connectivity, although this application has been controversial. We attempted to use large publicly available datasets (FCON 1000, ADHD 200, Human Connectome Project to determine whether consistent spatial patterns of Granger Causality are observed in typical fMRI data. For BOLD datasets from 1,240 typically developing subjects ages 7-40, we measured Granger causality between time series for every pair of 7,266 spherical ROIs covering the gray matter and 264 seed ROIs at hubs of the brain's functional network architecture. Granger causality estimates were strongly reproducible for connections in a test and replication sample (n=620 subjects for each group, as well as in data from a single subject scanned repeatedly, both during resting and passive video viewing. The same effect was even stronger in high temporal resolution fMRI data from the Human Connectome Project, and was observed independently in data collected during performance of 7 task paradigms. The spatial distribution of Granger causality reflected vascular anatomy with a progression from Granger causality sources, in Circle of Willis arterial inflow distributions, to sinks, near large venous vascular structures such as dural venous sinuses and at the periphery of the brain. Attempts to resolve BOLD phase differences with Granger causality should consider the possibility of reproducible vascular confounds, a problem that is independent of the known regional variability of the hemodynamic response.

  16. Cell lineage in vascularized bone transplantation.

    Science.gov (United States)

    Willems, Wouter F; Larsen, Mikko; Friedrich, Patricia F; Bishop, Allen T

    2014-01-01

    The biology behind vascularized bone allotransplantation remains largely unknown. We aim to study cell traffic between donor and recipient following bone auto-, and allografting. Vascularized femoral transplantation was performed with arteriovenous bundle implantation and short-term immunosuppression. Twenty male Piebald Virol Glaxo (PVG; RT1(c) ) rats received isotransplants from female PVG (RT1(c) ) rats and 22 male PVG rats received allografts from female Dark Agouti rats (DA, RT1(a) ), representing a major histocompatibility mismatch. Both groups were randomly analyzed at 4 or 18 weeks. Bone remodeling areas (inner and outer cortical samples) were labeled and laser capture microdissected. Analysis of sex-mismatch genes by real-time reverse transcription-polymerase chain reaction provided the relative Expression Ratio (rER) of donor (female) to recipient (male) cells. The rER was 0.456 ± 0.266 at 4 weeks and 0.749 ± 0.387 at 18 weeks (p = 0.09) in allotransplants. In isotransplants, the rER was 0.412 ± 0.239 and 0.467 ± 0.252 at 4 and 18 weeks, respectively (p = 0.21). At 4 weeks, the rER at the outer cortical area of isotransplants was significantly lower in isotransplants as compared with allotransplants (0.247 ± 0.181 vs. 0.549 ± 0.184, p = 0.007). Cells in the inner and outer cortical bone remodeling areas in isotransplants were mainly donor derived (rER 0.5) at 18 weeks. Applying novel methodology, we describe detailed cell traffic in vascularized bone transplants, elaborating our comprehension on bone transplantation. Copyright © 2013 Wiley Periodicals, Inc.

  17. Amplatzer vascular plugs in congenital cardiovascular malformations

    Directory of Open Access Journals (Sweden)

    Parag Barwad

    2013-01-01

    Full Text Available Background: Amplatzer vascular plugs (AVPs are devices ideally suited to close medium-to-large vascular communications. There is limited published literature regarding the utility of AVPs in congenital cardiovascular malformations (CCVMs. Aims: To describe the use of AVPs in different CCVMs and to evaluate their safety and efficacy. Materials and Methods: All patients who required an AVP for the closure of CCVM were included in this retrospective review of our catheterization laboratory data. The efficacy and safety of AVPs are reported. Results: A total of 39 AVPs were implanted in 31 patients. Thirteen (33% were AVP type I and 23 (59% were AVP type II. AVP type III were implanted in two patients and type IV in one patient. The major indications for their use included closure of pulmonary arteriovenous malformation (AVM (n = 7, aortopulmonary collaterals (n = 7, closure of a patent Blalock-Taussig shunt (n = 5, systemic AVM (n = 5, coronary AVM (n = 4, patent ductus arteriosus (PDA (n = 3, pulmonary artery aneurysms (n = 3, and venovenous collaterals (n = 2. Deployment of the AVP was done predominantly via the 5 - 7F Judkin′s right coronary guide catheter. Overall 92% of the AVPs could be successfully deployed and resulted in occlusion of the target vessel in all cases, within 10 minutes. No procedure-related or access site complication occurred. Conclusions: AVPs are versatile, easy to use, and effective devices to occlude the vascular communications in a variety of settings. AVP II is especially useful in the closure of tubular structures with a high flow.

  18. Percutaneous Cryotherapy of Vascular Malformation: Initial Experience

    Energy Technology Data Exchange (ETDEWEB)

    Cornelis, F., E-mail: francoiscornelis@hotmail.com [Institut Bergonie, Department of Radiology (France); Neuville, A. [Institut Bergonie, Department of Pathology (France); Labreze, C. [Pellegrin Hospital, Department of Pediatric Dermatology (France); Kind, M. [Institut Bergonie, Department of Radiology (France); Bui, B. [Institut Bergonie, Department of Oncology (France); Midy, D. [Pellegrin Hospital, Department of Vascular Surgery (France); Palussiere, J. [Institut Bergonie, Department of Radiology (France); Grenier, N. [Pellegrin Hospital, Department of Radiology (France)

    2013-06-15

    The present report describes a case of percutaneous cryotherapy in a 36-year-old woman with a large and painful pectoral venous malformation. Cryoablation was performed in a single session for this 9-cm mass with 24 h hospitalisation. At 2- and 6-month follow-up, the pain had completely disappeared, and magnetic resonance imaging demonstrated a significant decrease in size. Percutaneous cryoablation shows promise as a feasible and apparently safe method for local control in patients with symptomatic venous vascular malformations.

  19. The evolving integrated vascular surgery residency curriculum.

    Science.gov (United States)

    Smith, Brigitte K; Greenberg, Jacob A; Mitchell, Erica L

    2014-10-01

    Since their introduction several years ago, integrated (0 + 5) vascular surgery residency programs are being increasingly developed across the country. To date, however, there is no defined "universal" curriculum for these programs and each program is responsible for creating its own curriculum. The aim of this study was to review the experiences of current 0 + 5 program directors (PDs) to determine what factors contributed to the curricular development within their institution. Semistructured interviews were conducted with 0 + 5 PDs to explore their experiences with program development, factors influencing the latter, and rationale for current curricula. The interview script was loosely structured to explore several factors including time of incoming residents' first exposure to the vascular surgical service, timing and rationale behind the timing of core surgical rotations throughout the 5 year program, educational value of nonsurgical rotations, opportunities for leadership and scholarly activity, and influence the general surgery program and institutional climate had on curricular structure. All interviews were conducted by a single interviewer. All interviews were qualitatively analyzed using emergent theme analysis. Twenty-six 0 + 5 PDs participated in the study. A total of 69% believed establishing professional identity early reduces resident attrition and recommend starting incoming trainees on vascular surgical services. Sixty-two percent spread core surgical rotations over the first 3 years to optimize general surgical exposure and most of the programs have eliminated specific rotations, as they were not considered valuable to the goals of training. Factors considered most important by PDs in curricular development include building on existing institutional opportunities (96%), avoiding rotations considered unsuccessful by "experienced" programs (92%), and maintaining a good working relationship with general surgery (77%). Fifty-eight percent of

  20. Percutaneous Cryotherapy of Vascular Malformation: Initial Experience

    International Nuclear Information System (INIS)

    Cornelis, F.; Neuville, A.; Labrèze, C.; Kind, M.; Bui, B.; Midy, D.; Palussière, J.; Grenier, N.

    2013-01-01

    The present report describes a case of percutaneous cryotherapy in a 36-year-old woman with a large and painful pectoral venous malformation. Cryoablation was performed in a single session for this 9-cm mass with 24 h hospitalisation. At 2- and 6-month follow-up, the pain had completely disappeared, and magnetic resonance imaging demonstrated a significant decrease in size. Percutaneous cryoablation shows promise as a feasible and apparently safe method for local control in patients with symptomatic venous vascular malformations.

  1. Vascular access: a never-ending story.

    Science.gov (United States)

    Hedin, U

    2014-12-01

    Vascular surgeons are more and more becoming responsible for "life-line" creation well functioning and maintenance of hemodialysis patients and to provide a well functioning and multidisciplinary access service together with nefrologists, dialysis staff, and interventional radiology. For many, this sometimes arduous surgery with associated complicated clinical decision making, becomes a constant and challenging burden but much through the appearance of national and international guidelines and especially the endovascular technology, feasible solutions are easily at hand and the life as an access surgeon more pleasant. Here, basics in dialysis access care are presented together with some examples of novel available solutions to troublesome clinical problems.

  2. Vascular Plants of the Chimbote Wetlands, Peru

    OpenAIRE

    Arana, César; Salinas, Letty

    2013-01-01

    Los humedales de Chimbote (09°05’51"S; 78°32’52"O) presentan una flora vascular compuesta por 41 especies en 18 familias. El 61% magnoliópsidas y el 39% liliópsidas. Las familias con mayor número de especies fueron Poaceae, Cyperaceae y Asteraceae. Las formas de crecimiento dominantes fueron las hierbas (85%) seguidas de arbustos (10%). En comparación con los humedales costeros de Lima, en Chimbote se presenta mayor riqueza de especies que en Medio Mundo (16 especies) y El Paraíso (25), aunqu...

  3. Contrast-Enhanced Ultrasound in Vascular Surgery

    DEFF Research Database (Denmark)

    Bredahl, Kim; Mestre, Xavier Marti; Coll, Ramon Vila

    2017-01-01

    modalities. Ultrasound has only challenged these methods in assessment of carotid disease, aortic aneurysms, venous insufficiency, and thromboembolism and in surveillance of in situ bypasses. These practice patterns may change with the introduction of second-generation ultrasound contrast agents which...... are easy to use, manageable, and safe. This topical review attempts to summarize and highlight the current evidence and future prospects for contrast-enhanced ultrasound in vascular surgery, with a particular focus on opportunities in carotid and lower limb arteriosclerotic disease and surveillance after...

  4. Acute cerebral vascular accident associated with hyperperfusion

    International Nuclear Information System (INIS)

    Soin, J.S.; Burdine, J.A.

    1976-01-01

    Cerebral radionuclide angiography can demonstrate decreased or normal radioactivity in the affected region during the arterial phase in patients who have sustained a cerebral vascular accident and thus enhances the diagnostic specificity of the static brain image. In an occasional patient, however, a seemingly paradoxical pattern of regional hyperperfusion with a return to normal or subnormal perfusion following the acute phase has been observed. This phenomenon, called luxury perfusion, has been defined using intra-arterial 133 Xe for semiquantitative cerebral blood flow measurements and should be kept in mind as a potentially misleading cerebral imaging pattern

  5. Cerebral radiation necrosis: vascular and glial features

    Energy Technology Data Exchange (ETDEWEB)

    Husain, M M; Garcia, J H

    1976-12-21

    Glial and vascular abnormalities in brain, simulating intracranial neoplasia, are described in a patient who received radiation to the pituitary region for treatment of an adenoma, 13 months before death. In addition to the expected changes of cerebral radionecrosis, four interesting features are cited: (1) diffuse hyperplasia of capillaries in the cerebral cortex with marked endothelial hypertrophy; (2) abundant, large multipolar bizarre cells in the perivascular connective tissues; (3) focal astrocytic proliferation with many cells resembling either Alzheimer type I astrocytes or neoplastic cells, and (4) radiation changes in the non-irradiated brain.

  6. Dramatic Vascular Course of Behcet's Disease

    International Nuclear Information System (INIS)

    Elsharawy, Mohamed A.; Hassan, Khairi A.; Al-Awami, Majed; Al-Mulhim, Fatma A.

    2004-01-01

    Vascular involvement in Behcet's disease is rare (approximately 14% venous and 1.6% arterial), serious and recurrent. We report a case of Behcet's disease with deep venous thrombosis and right iliac pseudoaneurysm which was repaired with polytetrafluoroethylene (PTFE) graft. The patient received warfarin, aspirin, clopidogrel, immunosupressive and corticosteroids. Two months later the patient developed manifestations of superior vena cava thrombosis and the graft was blocked. Three months later, ischemia of the right foot deteriorated and left femoral artery crossover (PTFE) graft was performed. (author)

  7. [Characteristics of porcine thoracic arteries fixed with polyepoxy compound].

    Science.gov (United States)

    Yu, Xi-Xun; Chen, Huai-Qing

    2005-09-01

    To investigate the characteristics of porcine thoracic arteries fixed with ethylene glycol diglycidyl ether (EX-810) and to provide the proper scaffold materials for tissue-engineered blood vessel. The porcine thoracic arteries were respectively treated with 40 ml/L EX-810 and 6.25 g/L glutaraldehyde, and then they were examined with naked-eye, light microscope and scanning electron microscope. The fixation index determination, the amino acid analysis and the biomechanics test were also performed. The antigenicity of vascular tissues can be diminished by EX-810 through getting rid of cell in the vascular tissues or reducing the level of free amino groups in the vascular tissues. The structural integrity of vascular tissues can be preserved after treatment with EX-810. It was also found that the EX-810-fixed porcine vascular tissues appeared more similar to the natural vascular tissues in color and mechanical properties, and were more pliable than the glutaraldehyde-fixed tissues. The EX-810-fixed porcine thoracic arteries with low cytotoxicity and low antigenicity showed favorable characteristic similar to those of natural vessel, and it should be a promising material for fabricating scaffold of tissue-engineered blood vessel.

  8. Achados de imagem e alternativas terapêuticas das malformações vasculares periféricas Imaging findings and therapeutic alternatives for peripheral vascular malformations

    Directory of Open Access Journals (Sweden)

    Lucas Moretti Monsignore

    2010-06-01

    most recent classifications for peripheral vascular malformations are based on the blood flow (low or high and on the main vascular components (arterial, capillary, lymphatic or venous. Peripheral vascular malformations represent a diagnostic and therapeutic challenge, and complementary methods such as computed tomography, Doppler ultrasonography and magnetic resonance imaging, in association with clinical findings can provide information regarding blood flow characteristics and lesions extent. Arteriography and venography confirm the diagnosis, evaluate the lesions extent and guide the therapeutic decision making. Generally, low flow vascular malformations are percutaneously treated with sclerosing agents injection, while in high flow lesions the approach is endovascular, with permanent liquid or solid embolization agents.

  9. Structural and functional imaging for vascular targeted photodynamic therapy

    Science.gov (United States)

    Li, Buhong; Gu, Ying; Wilson, Brian C.

    2017-02-01

    Vascular targeted photodynamic therapy (V-PDT) has been widely used for the prevention or treatment of vascular-related diseases, such as localized prostate cancer, wet age-related macular degeneration, port wine stains, esophageal varices and bleeding gastrointestinal mucosal lesions. In this study, the fundamental mechanisms of vascular responses during and after V-PDT will be introduced. Based on the V-PDT treatment of blood vessels in dorsal skinfold window chamber model, the structural and functional imaging, which including white light microscopy, laser speckle imaging, singlet oxygen luminescence imaging, and fluorescence imaging for evaluating vascular damage will be presented, respectively. The results indicate that vessel constriction and blood flow dynamics could be considered as the crucial biomarkers for quantitative evaluation of vascular damage. In addition, future perspectives of non-invasive optical imaging for evaluating vascular damage of V-PDT will be discussed.

  10. Luteolin Ameliorates Hypertensive Vascular Remodeling through Inhibiting the Proliferation and Migration of Vascular Smooth Muscle Cells

    Directory of Open Access Journals (Sweden)

    Jie Su

    2015-01-01

    Full Text Available Objectives. Preliminary researches showed that luteolin was used to treat hypertension. However, it is still unclear whether luteolin has effect on the hypertensive complication such as vascular remodeling. The present study was designed to investigate the effect of luteolin on the hypertensive vascular remodeling and its molecular mechanism. Method and Results. We evaluated the effect of luteolin on aorta thickening of hypertension in spontaneous hypertensive rats (SHRs and found that luteolin could significantly decrease the blood pressure and media thickness of aorta in vivo. Luteolin could inhibit angiotensin II- (Ang II- induced proliferation and migration of vascular smooth muscle cells (VSMCs. Dichlorofluorescein diacetate (DCFH-DA staining result showed that luteolin reduced Ang II-stimulated ROS production in VSMCs. Furthermore, western blot and gelatin zymography results showed that luteolin treatment leaded to a decrease in ERK1/2, p-ERK1/2, p-p38, MMP2, and proliferating cell nuclear antigen (PCNA protein level. Conclusion. These data support that luteolin can ameliorate hypertensive vascular remodeling by inhibiting the proliferation and migration of Ang II-induced VSMCs. Its mechanism is mediated by the regulation of MAPK signaling pathway and the production of ROS.

  11. HMGB1 in vascular diseases : Its role in vascular inflammation and atherosclerosis

    NARCIS (Netherlands)

    de Souza, A. W. S.; Westra, J.; Limburg, P. C.; Bijl, M.; Kallenberg, C. G. M.

    2012-01-01

    The nuclear protein high mobility group box 1 (HMGB1) has been suggested to be involved in the pathogenesis of several vascular diseases such as systemic vasculitis and atherosclerosis. In systemic vasculitides including ANCA-associated vasculitis and Kawasaki disease, serum HMGB1 levels are higher

  12. New aspects of vascular remodelling: the involvement of all vascular cell types.

    Science.gov (United States)

    McGrath, John C; Deighan, Clare; Briones, Ana M; Shafaroudi, Majid Malekzadeh; McBride, Melissa; Adler, Jeremy; Arribas, Silvia M; Vila, Elisabet; Daly, Craig J

    2005-07-01

    Conventionally, the architecture of arteries is based around the close-packed smooth muscle cells and extracellular matrix. However, the adventitia and endothelium are now viewed as key players in vascular growth and repair. A new dynamic picture has emerged of blood vessels in a constant state of self-maintenance. Recent work raises fundamental questions about the cellular heterogeneity of arteries and the time course and triggering of normal and pathological remodelling. A common denominator emerging in hypertensive remodelling is an early increase in adventitial cell density suggesting that adventitial cells drive remodelling and may initiate subsequent changes such as re-arrangement of smooth muscle cells and extracellular matrix. The organization of vascular smooth muscle cells follows regular arrangements that can be modelled mathematically. In hypertension, new patterns can be quantified in these terms and give insights to how structure affects function. As with smooth muscle, little is known about the organization of the vascular endothelium, or its role in vascular remodelling. Current observations suggest that there may be a close relationship between the helical organization of smooth muscle cells and the underlying pattern of endothelial cells. The function of myoendothelial connections is a topic of great current interest and may relate to the structure of the internal elastic lamina through which the connections must pass. In hypertensive remodelling this must present an organizational challenge. The objective of this paper is to show how the functions of blood vessels depend on their architecture and a continuous interaction of different cell types and extracellular proteins.

  13. Cryospectrophotometric determination of tumor intravascular oxyhemoglobin saturations: dependence on vascular geometry and tumor growth.

    Science.gov (United States)

    Fenton, B M; Rofstad, E K; Degner, F L; Sutherland, R M

    1988-12-21

    To delineate the complex relationships between overall tumor oxygenation and vascular configuration, intravascular oxyhemoglobin (HbO2) saturation distributions were measured with cryospectrophotometric techniques. Four factors related to vascular morphometry and tumor growth were evaluated: a) vessel diameter, b) distance of vessel from the tumor surface, c) tumor volume, and d) vascular density. To measure intertumor heterogeneity, two murine sarcomas (RIF-1 and KHT) and two human ovarian carcinoma xenografts (OWI and MLS) were utilized. In contrast to skeletal muscle, a preponderance of very low HbO2 saturations was observed for both large and small tumors of all lines. Saturations up to about 90% were also generally present, however, even in very large tumors. Variations in vascular configuration were predominantly tumor-line dependent rather than due to inherent characteristics of the host vasculature, and widely disparate HbO2 distributions were found for alternate lines implanted in identical host mice. Although peripheral saturations remained fairly constant with tumor growth, HbO2 values were markedly lower for vessels nearer the tumor center and further decreased with increasing tumor volume. HbO2 saturations did not change substantially with increasing vascular density (except for KHT tumors), although density did decrease with increasing distance from tumor surface. Combined effects of vessel diameter, tumor volume, and vessel location on HbO2 saturations were complex and varied markedly with both tumor line and vessel class. For specific classes, HbO2 distributions correlated closely with radiobiological hypoxic fractions, i.e., for tumor lines in which hypoxic fraction increased substantially with tumor volume, corresponding HbO2 values decreased, while for lines in which hypoxic fraction remained constant, HbO2 values also were unchanged. Although these trends may also be a function of differing oxygen consumption rates between tumor lines

  14. Menstrual Cycle, Vocal Performance, and Laryngeal Vascular Appearance: An Observational Study on 17 Subjects.

    Science.gov (United States)

    Shoffel-Havakuk, Hagit; Carmel-Neiderman, Narin N; Halperin, Doron; Shapira Galitz, Yael; Levin, Dan; Haimovich, Yaara; Cohen, Oded; Abitbol, Jean; Lahav, Yonatan

    2018-03-01

    To assess the anatomical and functional features of the vocal folds during different phases of the female menstrual cycle. An observational study of 17 healthy fertile female volunteers not using hormonal contraception was carried out. Each volunteer underwent two examinations: first, during the early days of the menstrual cycle when progesterone levels are low (p-depletion), and second, during premenstruation when progesterone levels are high (p-peak). The workup included blood hormone levels, Voice Handicap Index, acoustic analysis, rigid telescopy, stroboscopy, and narrow band imaging. The videos were evaluated by blinded observers. The participants' mean age was 31.7 ± 5.6 (range 23-43). Progesterone levels were 13- to 45-fold higher in p-peak relative to p-depletion. No significant differences were detected in Voice Handicap Index scores, stroboscopic reports, or acoustic analysis between p-peak and p-depletion examinations. Analyzing the rigid telescopy and narrow band imaging videos, the observers tended to estimate the different laryngeal subsites more vascularized during the p-peak examination. Moreover, this tendency was significantly correlated with blood progesterone levels during the p-depletion examinations; the lower the blood progesterone levels were during p-depletion, the higher the probability for the observers to estimate the p-peak examinations more vascularized (P value = 0.024). Alterations in laryngeal vascular characteristics are evident throughout the menstrual cycle and may suggest increased congestion during premenstrual days. Variations in progesterone levels during the menstrual cycle correlate with laryngeal vascular changes. Hormone-related alterations in vocal folds' vascularity may have a role in the variability of vocal performance in certain women. Copyright © 2018 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  15. 社区老年人心脑血管疾病共病抑郁障碍流行病学特征及其影响因素分析%Epidemiology characteristics and its influence factor analysis in community elderly patients with cardiac cerebral and vascular diseases comorbid depressive disorder

    Institute of Scientific and Technical Information of China (English)

    金莹; 秦虹云; 瞿正万

    2012-01-01

    Objective To invesligale the slalus of comorbid depressive disorders and its risk factor in communily elderly palienls with Cardiac Cerebral And Vascular Diseases ( CCVD) , to provide important basis for disease prevention and control in communily. Methods 3311 registered permanent old man were surveyed in random pudong new area 15 street town, 574 old men with obvious CCVD were used for depressive disorder comorbidity survey ( disease) , and 574 old men had no obvious physical and mental illness as a control (the healthy group). Survey tools including wrote "general condition investigation questionnaire" and "the diagnostic and statistical manual of mental disorders ( DSM-IV) axis I obstacles clinical examination by patients version( SCID-I/P) ". Multi factors togistic regression analysis were used. Results 164 cases in disease group comorbid depressive disorder (28. 6% ), higher than the health group( 17. 1% ) ( x2= 21. 54, P < 0. 01); togistic regression analysis found that older age,women,family economic difficulties,family relationship bad were the independently associated risk factors of depressive disorders. Conclusions The elderly CCVD patients have a higher rates of comorbidity depression than the healthy elderly population, take effective intervention methods can reduce the prevalence and help to improve the quality of life in the old men.%目的 调查社区老年人心脑血管疾病患者共病抑郁障碍的现况及易感因素,为社区疾病防治提供重要依据.方法 随机抽取浦东新区15个街镇在册常住老年人共调查3311名,将患有明显心脑血管疾病的574名老年人进行抑郁障碍共病调查(疾病组),574名无明显躯体和精神疾病者作对照(健康组).调查工具包括自编"一般状况调查问卷"及"美国精神障碍诊断与统计手册第4版(DSM-Ⅳ)轴Ⅰ障碍定式临床检查患者版(SCID-I/P)",进行多因素Logistic回归分析.结果 疾病组中164例共病抑郁障碍(28.6%),

  16. Vascular complications of prosthetic inter-vertebral discs

    OpenAIRE

    Daly, Kevin J.; Ross, E. Raymond S.; Norris, Heather; McCollum, Charles N.

    2006-01-01

    Five consecutive cases of prosthetic inter-vertebral disc displacement with severe vascular complications on revisional surgery are described. The objective of this case report is to warn spinal surgeons that major vascular complications are likely with anterior displacement of inter-vertebral discs. We have not been able to find a previous report on vascular complications associated with anterior displacement of prosthetic inter-vertebral discs. In all five patients the prosthetic disc had e...

  17. Brain Arterial Diameters as a Risk Factor for Vascular Events.

    Science.gov (United States)

    Gutierrez, Jose; Cheung, Ken; Bagci, Ahmet; Rundek, Tatjana; Alperin, Noam; Sacco, Ralph L; Wright, Clinton B; Elkind, Mitchell S V

    2015-08-06

    Arterial luminal diameters are routinely used to assess for vascular disease. Although small diameters are typically considered pathological, arterial dilatation has also been associated with disease. We hypothesize that extreme arterial diameters are biomarkers of the risk of vascular events. Participants in the Northern Manhattan Study who had a time-of-flight magnetic resonance angiography were included in this analysis (N=1034). A global arterial Z-score, called the brain arterial remodeling (BAR) score, was obtained by averaging the measured diameters within each individual. Individuals with a BAR score -2 and 2 SDs had the largest diameters. All vascular events were recorded prospectively after the brain magnetic resonance imaging. Spline curves and incidence rates were used to test our hypothesis. The association of the BAR score with death (P=0.001), vascular death (P=0.02), any vascular event (P=0.05), and myocardial infarction (P=0.10) was U-shaped except for ischemic stroke (P=0.74). Consequently, incidence rates for death, vascular death, myocardial infarction, and any vascular event were higher in individuals with the largest diameters, whereas individuals with the smallest diameters had a higher incidence of death, vascular death, any vascular event, and ischemic stroke compared with individuals with average diameters. The risk of death, vascular death, and any vascular event increased at both extremes of brain arterial diameters. The pathophysiology linking brain arterial remodeling to systemic vascular events needs further research. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  18. 3D-Printed Biodegradable Polymeric Vascular Grafts.

    Science.gov (United States)

    Melchiorri, A J; Hibino, N; Best, C A; Yi, T; Lee, Y U; Kraynak, C A; Kimerer, L K; Krieger, A; Kim, P; Breuer, C K; Fisher, J P

    2016-02-04

    Congenital heart defect interventions may benefit from the fabrication of patient-specific vascular grafts because of the wide array of anatomies present in children with cardiovascular defects. 3D printing is used to establish a platform for the production of custom vascular grafts, which are biodegradable, mechanically compatible with vascular tissues, and support neotissue formation and growth. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Pathophysiology of Headaches with a Prominent Vascular Component

    Directory of Open Access Journals (Sweden)

    Juan A Pareja

    1996-01-01

    Full Text Available Vascular changes, whether preliminary or secondary, seem to accompany most headaches. The literature concerning pathophysiological mechanisms in headaches where vascular phenomena are a major, integral part, ie, migraine and cluster headache syndrome, is reviewed and the most common forms of headache associated with cerebrovascular disease are discussed. Emphasis is placed on the vascular phenomena and on the abundant hypotheses and theories regarding headache mechanisms. This review also presents alternative explanatory models, and compares the available anatomical, physiological and biochemical results.

  20. Vascular hemichorea: case report and review

    Directory of Open Access Journals (Sweden)

    Bárbara Martínez Alfonzo

    2014-04-01

    Full Text Available Chorea rarely complicates ischemic or hemorrhagic cerebral vascular lesions. Clinical symptoms usually involve one side of the body while the injury is situated on the contralateral cerebral hemisphere. Spontaneous remission is the norm, but sometimes symptomatic treatment is required. A 58-year-old male patient who suffers from untreated high blood pressure, type II obesity, smokes 6 packs of cigarettes per year and has a moderate intake of alcohol is presented. The patient’s recent history began three days before he appeared at the Emergency Department. His symptoms were ceaseless, involuntary movements in his left arm and foot during day and night with no restriction of voluntary movements. Physical examination and laboratory tests revealed no other findings. Magnetic resonance imaging of the brain showed hyperintensity in the right posterolateral thalamic region consistent with ischemic cerebrovascular disease. Symptomatic therapy was indicated and his underlying conditions were addressed. The importance of this case lies on the low prevalence as well as the scarcity of publications regarding vascular causes of hemichorea, including diagnosis, therapy and prognosis.

  1. Connections matter: channeled hydrogels to improve vascularization

    Directory of Open Access Journals (Sweden)

    Severin eMuehleder

    2014-11-01

    Full Text Available The use of cell-laden hydrogels to engineer soft tissue has been emerging within the past years. Despite several newly developed and sophisticated techniques to encapsulate different cell types the importance of vascularization of the engineered constructs is often underestimated. As a result, cell death within a construct leads to impaired function and inclusion of the implant. Here, we discuss the fabrication of hollow channels within hydrogels as a promising strategy to facilitate vascularization. Furthermore, we present an overview on the feasible use of removable spacers, 3D laser- and planar processing strategies to create channels within hydrogels. The implementation of these structures promotes control over cell distribution and increases oxygen transport and nutrient supply in vitro. However, many studies lack the use of endothelial cells in their approaches leaving out an important factor to enhance vessel ingrowth and anastomosis formation upon implantation. In addition, the adequate endothelial cell type needs to be considered to make these approaches bridge the gap to in vivo applications.

  2. Connections matter: channeled hydrogels to improve vascularization.

    Science.gov (United States)

    Muehleder, Severin; Ovsianikov, Aleksandr; Zipperle, Johannes; Redl, Heinz; Holnthoner, Wolfgang

    2014-01-01

    The use of cell-laden hydrogels to engineer soft tissue has been emerging within the past years. Despite, several newly developed and sophisticated techniques to encapsulate different cell types the importance of vascularization of the engineered constructs is often underestimated. As a result, cell death within a construct leads to impaired function and inclusion of the implant. Here, we discuss the fabrication of hollow channels within hydrogels as a promising strategy to facilitate vascularization. Furthermore, we present an overview on the feasible use of removable spacers, 3D laser-, and planar processing strategies to create channels within hydrogels. The implementation of these structures promotes control over cell distribution and increases oxygen transport and nutrient supply in vitro. However, many studies lack the use of endothelial cells in their approaches leaving out an important factor to enhance vessel ingrowth and anastomosis formation upon implantation. In addition, the adequate endothelial cell type needs to be considered to make these approaches bridge the gap to in vivo applications.

  3. Maintenance of vascular access patency in pediatrics

    International Nuclear Information System (INIS)

    Hoffer, F.A.; Wyly, J.B.; Fellows, K.E.; Harmon, W.; Levey, R.H.

    1986-01-01

    The patency of vascular access shunts and fistulae has been prolonged by a combined surgical and radiological approach that includes percutaneous transluminal angioplasty (PTA), surgical revision, thrombectomy, and thrombolysis. Over the last 3 years, 35 vascular accesses in 27 patients were found to have angiographic abnormality. PTA was performed 32 times of 19 accesses and 7 PTAs resulted in patent accesses by the end of the study. Surgical revision was performed 9 times on 8 accesses and 2 of the surgical revisions resulted in a patent access by the end of the study. Concerning Thomas femoral shunts, PTA prolonged the patency by 2.2 months and surgical revision by 3.8 months per procedure. Concerning arteriovenous (AV) fistulae, PTA prolonged the patency by 4.3 months and surgical revision by 3.5 months per procedure. A combination of procedures effectively doubles the duration of patency of Thomas femoral shunts and almost triples the duration of patency of AV fistulae in children. Forty-one percent of these accesses remain open 1 year following the initiation of these procedures. (orig.)

  4. Cerebral Vascular Injury in Traumatic Brain Injury.

    Science.gov (United States)

    Kenney, Kimbra; Amyot, Franck; Haber, Margalit; Pronger, Angela; Bogoslovsky, Tanya; Moore, Carol; Diaz-Arrastia, Ramon

    2016-01-01

    Traumatic cerebral vascular injury (TCVI) is a very frequent, if not universal, feature after traumatic brain injury (TBI). It is likely responsible, at least in part, for functional deficits and TBI-related chronic disability. Because there are multiple pharmacologic and non-pharmacologic therapies that promote vascular health, TCVI is an attractive target for therapeutic intervention after TBI. The cerebral microvasculature is a component of the neurovascular unit (NVU) coupling neuronal metabolism with local cerebral blood flow. The NVU participates in the pathogenesis of TBI, either directly from physical trauma or as part of the cascade of secondary injury that occurs after TBI. Pathologically, there is extensive cerebral microvascular injury in humans and experimental animal, identified with either conventional light microscopy or ultrastructural examination. It is seen in acute and chronic TBI, and even described in chronic traumatic encephalopathy (CTE). Non-invasive, physiologic measures of cerebral microvascular function show dysfunction after TBI in humans and experimental animal models of TBI. These include imaging sequences (MRI-ASL), Transcranial Doppler (TCD), and Near InfraRed Spectroscopy (NIRS). Understanding the pathophysiology of TCVI, a relatively under-studied component of TBI, has promise for the development of novel therapies for TBI. Published by Elsevier Inc.

  5. Aortic stenosis and vascular calcifications in alkaptonuria.

    Science.gov (United States)

    Hannoush, Hwaida; Introne, Wendy J; Chen, Marcus Y; Lee, Sook-Jin; O'Brien, Kevin; Suwannarat, Pim; Kayser, Michael A; Gahl, William A; Sachdev, Vandana

    2012-02-01

    Alkaptonuria is a rare metabolic disorder of tyrosine catabolism in which homogentisic acid (HGA) accumulates and is deposited throughout the spine, large joints, cardiovascular system, and various tissues throughout the body. In the cardiovascular system, pigment deposition has been described in the heart valves, endocardium, pericardium, aortic intima and coronary arteries. The prevalence of cardiovascular disease in patients with alkaptonuria varies in previous reports. We present a series of 76 consecutive adult patients with alkaptonuria who underwent transthoracic echocardiography between 2000 and 2009. A subgroup of 40 patients enrolled in a treatment study underwent non-contrast CT scans and these were assessed for vascular calcifications. Six of the 76 patients had aortic valve replacement. In the remaining 70 patients, 12 patients had aortic sclerosis and 7 patients had aortic stenosis. Unlike degenerative aortic valve disease, we found no correlation with standard cardiac risk factors. There was a modest association between the severity of aortic valve disease and joint involvement, however, we saw no correlation with urine HGA levels. Vascular calcifications were seen in the coronaries, cardiac valves, aortic root, descending aorta and iliac arteries. These findings suggest an important role for echocardiographic screening of alkaptonuria patients to detect valvular heart disease and cardiac CT to detect coronary artery calcifications. Published by Elsevier Inc.

  6. Axon guidance molecules in vascular patterning.

    Science.gov (United States)

    Adams, Ralf H; Eichmann, Anne

    2010-05-01

    Endothelial cells (ECs) form extensive, highly branched and hierarchically organized tubular networks in vertebrates to ensure the proper distribution of molecular and cellular cargo in the vertebrate body. The growth of this vascular system during development, tissue repair or in disease conditions involves the sprouting, migration and proliferation of endothelial cells in a process termed angiogenesis. Surprisingly, specialized ECs, so-called tip cells, which lead and guide endothelial sprouts, share many feature with another guidance structure, the axonal growth cone. Tip cells are motile, invasive and extend numerous filopodial protrusions sensing growth factors, extracellular matrix and other attractive or repulsive cues in their tissue environment. Axonal growth cones and endothelial tip cells also respond to signals belonging to the same molecular families, such as Slits and Roundabouts, Netrins and UNC5 receptors, Semaphorins, Plexins and Neuropilins, and Eph receptors and ephrin ligands. Here we summarize fundamental principles of angiogenic growth, the selection and function of tip cells and the underlying regulation by guidance cues, the Notch pathway and vascular endothelial growth factor signaling.

  7. Late vascular effects in irradiated mice brain

    International Nuclear Information System (INIS)

    Yoshii, Yoshihiko; Maki, Yutaka; Phillips, T.L.

    1982-01-01

    The whole brains of mice were irradiated with 250 kVp X-ray at 120 rad min -1 (1.6 mm Cu HVL, TSD 50 cm) and a histological study was done. The dose range of X-irradiation was from 1300 to 2500 rads. i.e., 1300, 1500, 1750, 2000, and 2500 rads. In the microscopic examination, the mice were killed at the regular postirradiation intervals of between 15 and 20, 31 and 40, 41 and 50, 51 and 60, 61 and 70, 71 and 80, 81 and 90, 139 and 177 weeks. A histological examination was performed by a morphometric estimation of vascular lesion in which the degree of the damage to the arterial system was scored through whole serial brain sections. Necrosis (encephalomalacia), atrophy, cell infiltration, and telangiectatic vascular change of the brain, caused as a result of the fibrinoid necrosis of the large artery were observed. Incidence of the fibrinoid necrosis increased dose dependently between 41 and 87 weeks after irradiation. Mean score of fibrinoid necrosis increased dose dependently approximately 60 weeks after irradiation. It is suggested that scores of large vessel damage do relate to dose at 41 - 87 weeks and can be used to quantify the vessel injury and a fibrinoid necrosis of the large vessels may relate to the incidence of radionecrosis. (author)

  8. [Central blood pressure and vascular damage].

    Science.gov (United States)

    Pérez-Lahiguera, Francisco; Rodilla, Enrique; Costa, José Antonio; Pascual, José María

    2015-07-20

    The aim of this study was to assess the relationship between central blood pressure and vascular damage. This cross-sectional study involved 393 never treated hypertensive patients (166 women). Clinical blood pressure (BP), 24h blood pressure (BP24h) and central blood pressure (CBP) were measured. Vascular organ damage (VOD) was assessed by calculating the albumin/creatinine ratio (ACR), wave pulse pressure velocity and echocardiographic left ventricular mass index (LVMI). Patients with VOD had higher values of BP, BP24h, and CBP than patients without ACR. When comparing several systolic BP, systolic BP24h had a higher linear correlation with CBP (Z Steiger test: 2.26; P=.02) and LVMI (Z Steiger test: 3.23; P=.01) than PAC. In a multiple regression analysis corrected by age, sex and metabolic syndrome, all pressures were related with VOD but systolic BP24h showed the highest correlation. In a logistic regression analysis, having the highest tercile of systolic BP24h was the stronger predictor of VOD (multivariate odds ratio: 3.4; CI 95%: 2.5-5.5, P=.001). CBP does not have more correlation with VOD than other measurements of peripheral BP. Systolic BP24h is the BP measurement that best predicts VOD. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

  9. Effective Dosage of Midazolam to Erase the Memory of Vascular Pain During Propofol Administration.

    Science.gov (United States)

    Boku, Aiji; Inoue, Mika; Hanamoto, Hiroshi; Oyamaguchi, Aiko; Kudo, Chiho; Sugimura, Mitsutaka; Niwa, Hitoshi

    Intravenous sedation with propofol is often administered to anxious patients in dental practice. Pain on injection of propofol is a common adverse effect. This study aimed to determine the age-adjusted doses of midazolam required to erase memory of vascular pain of propofol administration and assess whether the Ramsay Sedation Scale (RSS) after the pretreatment of midazolam was useful to predict amnesia of the vascular pain of propofol administration. A total of 246 patients with dental phobia requiring dental treatment under intravenous sedation were included. Patients were classified according to their age: 30s, 40s, 50s, and 60s. Three minutes after administration of a predetermined dose of midazolam, propofol was infused continuously. After completion of the dental procedure, patients were interviewed about the memory of any pain or discomfort in the injection site or forearm. The dosage of midazolam was determined using the Dixon up-down method. The first patient was administered 0.03 mg/kg, and if memory of vascular pain remained, the dosage was increased by 0.01 mg/kg for the next patient, and then if the memory was erased, the dosage was decreased by 0.01 mg/kg. The effective dosage of midazolam in 95% of each age group for erasing the memory of propofol vascular pain (ED95) was determined using logistic analysis. The accuracy of RSS to predict the amnesia of injection pain was assessed by receiver operating characteristic (ROC) analysis. The ED95 of midazolam to erase the memory of propofol vascular pain was 0.061 mg/kg in patients in their 30s, 0.049 mg/kg in patients in their 40s, 0.033 mg/kg in patients in their 50s, and 0.033 mg/kg in patients in their 60s. The area under the ROC curve was 0.31. The ED95 of midazolam required to erase the memory of propofol vascular pain demonstrated a downward trend with age. On the other hand, it was impossible to predict the amnesia of propofol vascular pain using the RSS.

  10. Management of vascular anomalies: Review of institutional management algorithm

    Directory of Open Access Journals (Sweden)

    Lalit K Makhija

    2017-01-01

    Full Text Available Introduction: Vascular anomalies are congenital lesions broadly categorised into vascular tumour (haemangiomas and vascular dysmorphogenesis (vascular malformation. The management of these difficult problems has lately been simplified by the biological classification and multidisciplinary approach. To standardise the treatment protocol, an algorithm has been devised. The study aims to validate the algorithm in terms of its utility and presents our experience in managing vascular anomalies. Materials and Methods: The biological classification of Mulliken and Glowacki was followed. A detailed algorithm for management of vascular anomalies has been devised in the department. The protocol is being practiced by us since the past two decades. The data regarding the types of lesions and treatment modality used were maintained. Results and Conclusion: This study was conducted from 2002 to 2012. A total of 784 cases of vascular anomalies were included in the study of which 196 were haemangiomas and 588 were vascular malformations. The algorithmic approach has brought an element of much-needed objectivity in the management of vascular anomalies. This has helped us to define the management of particular lesion considering its pathology, extent and aesthetic and functional consequences of ablation to a certain extent.

  11. 3D Multiscale Modelling of Angiogenesis and Vascular Tumour Growth

    KAUST Repository

    Perfahl, H.

    2012-11-01

    We present a three-dimensional, multiscale model of vascular tumour growth, which couples nutrient/growth factor transport, blood flow, angiogenesis, vascular remodelling, movement of and interactions between normal and tumour cells, and nutrient-dependent cell cycle dynamics within each cell. We present computational simulations which show how a vascular network may evolve and interact with tumour and healthy cells. We also demonstrate how our model may be combined with experimental data, to predict the spatio-temporal evolution of a vascular tumour.

  12. 3D Multiscale Modelling of Angiogenesis and Vascular Tumour Growth

    KAUST Repository

    Perfahl, H.; Byrne, H. M.; Chen, T.; Estrella, V.; Alarcó n, T.; Lapin, A.; Gatenby, R. A.; Gillies, R. J.; Lloyd, M. C.; Maini, P. K.; Reuss, M.; Owen, M. R.

    2012-01-01

    We present a three-dimensional, multiscale model of vascular tumour growth, which couples nutrient/growth factor transport, blood flow, angiogenesis, vascular remodelling, movement of and interactions between normal and tumour cells, and nutrient-dependent cell cycle dynamics within each cell. We present computational simulations which show how a vascular network may evolve and interact with tumour and healthy cells. We also demonstrate how our model may be combined with experimental data, to predict the spatio-temporal evolution of a vascular tumour.

  13. Endoscopic Management of Vascular Sinonasal Tumors, Including Angiofibroma.

    Science.gov (United States)

    Snyderman, Carl H; Pant, Harshita

    2016-06-01

    The greatest challenge in the surgical treatment of angiofibromas is dealing with the hypervascularity of these tumors. Staging systems that take into account the vascularity of the tumor may be more prognostic. A variety of treatment strategies are used to deal with the vascularity of angiofibromas, including preoperative embolization, segmentation of the tumor into vascular territories, use of hemostatic tools, and staging of surgery. Even large angiofibromas with intracranial extension and residual vascularity can be successfully managed by a skull base team using endoscopic techniques. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. 3-D Ultrasound Vascularity Assessment for Breast Cancer Diagnosis

    National Research Council Canada - National Science Library

    Carson, Paul

    1997-01-01

    This project is to improve the diagnosis and management of patients with breast cancer through development and evaluation of 3D ultrasound imaging and quantification techniques emphasizing vascularity...

  15. The vascular basement membrane in the healthy and pathological brain.

    Science.gov (United States)

    Thomsen, Maj S; Routhe, Lisa J; Moos, Torben

    2017-10-01

    The vascular basement membrane contributes to the integrity of the blood-brain barrier (BBB), which is formed by brain capillary endothelial cells (BCECs). The BCECs receive support from pericytes embedded in the vascular basement membrane and from astrocyte endfeet. The vascular basement membrane forms a three-dimensional protein network predominantly composed of laminin, collagen IV, nidogen, and heparan sulfate proteoglycans that mutually support interactions between BCECs, pericytes, and astrocytes. Major changes in the molecular composition of the vascular basement membrane are observed in acute and chronic neuropathological settings. In the present review, we cover the significance of the vascular basement membrane in the healthy and pathological brain. In stroke, loss of BBB integrity is accompanied by upregulation of proteolytic enzymes and degradation of vascular basement membrane proteins. There is yet no causal relationship between expression or activity of matrix proteases and the degradation of vascular matrix proteins in vivo. In Alzheimer's disease, changes in the vascular basement membrane include accumulation of Aβ, composite changes, and thickening. The physical properties of the vascular basement membrane carry the potential of obstructing drug delivery to the brain, e.g. thickening of the basement membrane can affect drug delivery to the brain, especially the delivery of nanoparticles.

  16. Evaluating Peripheral Vascular Injuries: Is Color Doppler Enough for Diagnosis?

    Directory of Open Access Journals (Sweden)

    Mohd Lateef Wani

    2014-03-01

    Full Text Available Background:: Vascular injury poses a serious threat to limb and life. Thus, diagnosis should be made immediately with minimally invasive methods. Doppler is a good aid in diagnosis of vascular injury. Methods:: The present prospective study was conducted on 150 patients who presented with soft signs (the signs which are suggestive but not confirmatory of vascular injury. They were subjected to color Doppler examination before exploration. The patients with the features of vascular injury on color Doppler were subjected to exploration. On the other hand, those who had normal Doppler were subjected to CT- angiography. Then, the findings of the exploration were matched with those of color Doppler. The data were analyzed using the SPSS statistical software. Results:: Out of the 150 Doppler examinations, 110 (73.33% were reported as positive, while 40 were reported as negative for vascular injury. These were subjected to CT-angiography and seven of them had the features of vascular injury on CT-angiography. All the patients with positive Doppler or CT angiography findings were subjected to exploration. Doppler had a sensitivity of 94% and specificity of 82.5% in diagnosis of vascular injury using Binary classification test. Conclusions:: Color Doppler is an easily available, reliable, and handy method of diagnosing a vascular injury. It has a very high sensitivity and specificity in diagnosis of vascular injuries.

  17. Spontaneous Dissection of the Renal Artery in Vascular Ehlers-Danlos Syndrome

    Directory of Open Access Journals (Sweden)

    Filipa Pereira

    2015-01-01

    Full Text Available Ehlers-Danlos syndrome (EDS is a rare heterogeneous group of connective tissue disorders. The vascular type (vEDS is an autosomal dominant disorder caused by heterozygous mutations in the COL3A1 gene predisposing to premature arterial, intestinal, or uterine rupture. We report a case of a 38-year-old woman with a recent diagnosis of vEDS admitted in the Emergency Department with a suspicion of a pyelonephritis that evolved to a cardiopulmonary arrest. A fatal retroperitoneal hematoma related with a haemorrhagic dissection of the right renal artery was found after emergency surgery. This case highlights the need to be aware of the particular characteristics of vEDS, such as a severe vascular complication that can lead to a fatal outcome.

  18. The behavior of the vascular system in the experimental tumor radiotherapy

    International Nuclear Information System (INIS)

    Yamaura, Hirotsugu; Matsuzawa, Taiju; Sato, Haruo; Ito, Yasuhiko.

    1975-01-01

    The rat ascites hepatoma AH109A transplanted and grown in the rat transparent chamber developed a tumor specific vascular system, the process of which was quantitatively studied because of the vascular length, surface area, and volume per mm 3 of tissue. The values changed characteristically in each stage of the course. The tumor was irradiated in a chamber with 3000 R of 60 Co γ-rays, and the tumor cells died leaving behind highly dense capillary networks, which gradually returned to normal level by 7 days after irradiation. The blood vessels, either preformed or newly formed, in the control tissue without tumor were not damaged by this dose. But the proliferation of capillary buds were inhibited slightly with 400 R and completely with 4000 R. (auth.)

  19. The behavior of the vascular system in the experimental tumor radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Yamaura, H; Matsuzawa, T; Sato, H [Tohoku Univ., Sendai (Japan). Research Inst. for Tuberculosis, Leprosy and Cancer; Ito, Yasuhiko

    1975-07-01

    The rat ascites hepatoma AH109A transplanted and grown in the rat transparent chamber developed a tumor specific vascular system, the process of which was quantitatively studied because of the vascular length, surface area, and volume per mm/sup 3/ of tissue. The values changed characteristically in each stage of the course. The tumor was irradiated in a chamber with 3000 R of /sup 60/Co ..gamma..-rays, and the tumor cells died leaving behind highly dense capillary networks, which gradually returned to normal level by 7 days after irradiation. The blood vessels, either preformed or newly formed, in the control tissue without tumor were not damaged by this dose. But the proliferation of capillary buds were inhibited slightly with 400 R and completely with 4000 R.

  20. ENERGY CHARACTERISTICS OF ETHANOL CHARACTERISTICS ...

    African Journals Online (AJOL)

    eobe

    CHARACTERISTICS OF ETHANOL-DIESEL MIX FOR AUTOMOTIVE. DIESEL ... diesel engine and the engine speed, torque, power and specific fuel consumption (sfc) were determine .... heated on an electric stove and stirred continuously.

  1. Cardiac Risk Assessment, Morbidity Prediction, and Outcome in the Vascular Intensive Care Unit.

    LENUS (Irish Health Repository)

    Dover, Mary

    2013-09-17

    Objectives: The aim of this study is to examine the predictive value of the Lee revised cardiac risk index (RCRI) for a standard vascular intensive care unit (ICU) population as well as assessing the utility of transthoracic echocardiography and the impact of prior coronary artery disease (CAD) and coronary revascularization on patient outcome. Design: This is a retrospective review of prospectively maintained Vascubase and prospectively collected ICU data. Materials and Methods: Data from 363 consecutive vascular ICU admissions were collected. Findings were used to calculate the RCRI, which was then correlated with patient outcomes. All patients were on optimal medical therapy (OMT) in the form of cardioselective β-blocker, aspirin, statin, and folic acid. Results: There was no relationship found between a reduced ejection fraction and patient outcome. Mortality was significantly increased for patients with left ventricular hypertrophy (LVH) as identified on echo (14.9% vs 6.5%, P = .028). The overall complication rates were significantly elevated for patients with valvular dysfunction. Discrimination for the RCRI on receiver-operating characteristic analysis was poor, with an area under the receiver-operating characteristic curve of .621. Model calibration was reasonable with an Hosmer-Lemeshow Ĉ statistic of 2.726 (P = .256). Of those with known CAD, 41.22% of the patients receiving best medical treatment developed acute myocardial infarction (AMI) compared to 35.3% of those who previously underwent percutaneous cardiac intervention and 23.5% of those who had undergone coronary artery bypass grafting. There was 3-fold increase in major adverse clinical events in patients with troponin rise and LVH. Conclusions: The RCRI\\'s discriminatory capacity is low, and this raises difficulties in assessing cardiac risk in patients undergoing vascular intervention. The AMI is highest in the OMT group without prior cardiac intervention, which mandates protocols to

  2. VEGFR tyrosine kinase inhibitor II (VRI) induced vascular insufficiency in zebrafish as a model for studying vascular toxicity and vascular preservation

    International Nuclear Information System (INIS)

    Li, Shang; Dang, Yuan Ye; Oi Lam Che, Ginny; Kwan, Yiu Wa; Chan, Shun Wan; Leung, George Pak Heng; Lee, Simon Ming Yuen; Hoi, Maggie Pui Man

    2014-01-01

    In ischemic disorders such as chronic wounds and myocardial ischemia, there is inadequate tissue perfusion due to vascular insufficiency. Besides, it has been observed that prolonged use of anti-angiogenic agents in cancer therapy produces cardiovascular toxicity caused by impaired vessel integrity and regeneration. In the present study, we used VEGFR tyrosine kinase inhibitor II (VRI) to chemically induce vascular insufficiency in zebrafish in vivo and human umbilical vein endothelial cells (HUVEC) in vitro to further study the mechanisms of vascular morphogenesis in these pathological conditions. We also explored the possibility of treating vascular insufficiency by enhancing vascular regeneration and repair with pharmacological intervention. We observed that pretreatment of VRI induced blood vessel loss in developing zebrafish by inhibiting angiogenesis and increasing endothelial cell apoptosis, accompanied by down-regulation of kdr, kdrl and flt-1 genes expression. The VRI-induced blood vessel loss in zebrafish could be restored by post-treatment of calycosin, a cardiovascular protective isoflavone. Similarly, VRI induced cytotoxicity and apoptosis in HUVEC which could be rescued by calycosin post-treatment. Further investigation of the underlying mechanisms showed that the PI3K/AKT/Bad cell survival pathway was a main contributor of the vascular regenerative effect of calycosin. These findings indicated that the cardiovascular toxicity in anti-angiogenic therapy was mainly caused by insufficient endothelial cell survival, suggesting its essential role in vascular integrity, repair and regeneration. In addition, we showed that VRI-induced blood vessel loss in zebrafish represented a simple and effective in vivo model for studying vascular insufficiency and evaluating cancer drug vascular toxicities. - Highlights: • In vivo VRI model • Rescue effects of calycosin • Calycosin EC survival pathways

  3. Vascular injuries of the upper extremity Lesões vasculares de membros superiores

    Directory of Open Access Journals (Sweden)

    Raafat Shalabi

    2006-12-01

    Full Text Available OBJECTIVE: This study analyzes the causes of injuries, presentations, surgical approaches, outcome and complications of vascular trauma of the upper limbs, in spite of limited hospital resources. METHODS: A 5-year retrospective analysis. From 01/01/2001 to 31/12/2005, 165 patients were operated for vascular injuries at King Fahd Hospital, Medina, Saudi Arabia. Of all peripheral vascular trauma patients (115, upper limb trauma was present in 58. Diagnosis was made by physical examination and hand-held Doppler alone or in combination with Doppler scan/angiography. Primary vascular repair was performed whenever possible; otherwise, the interposition vein graft was used. Fasciotomy was considered when required. Patients with unsalvageable lower extremity injury requiring primary amputation were excluded from the study. RESULTS: Fifty patients were male (86% and eight were female (14%, aged between 2.5-55 years (mean 23 years. Mean duration of presentation was 8 h after the injury. The most common etiological factor was road traffic accidents, accounting for 50.5% in the blunt trauma group and 33% among all penetrating and stab wound injuries. Incidence of concomitant orthopedic injuries was very high in our study (51%. The brachial artery was the most affected (51%. Interposition vein grafts were used in 53% of the cases. Limb salvage rate was 100%. CONCLUSION: Patients who suffer vascular injuries of the upper extremities should be transferred to vascular surgery centers as soon as possible. Decisive management of peripheral vascular trauma will maximize patient survival and limb salvage. Priorities must be established in the management of associated injuries, and delay must be avoided when ischemic changes are present.OBJETIVO: Este estudo analisa as causas de lesões, apresentação, abordagens cirúrgicas, desfechos e complicações do trauma vascular de membros superiores, apesar de recursos hospitalares limitados. MÉTODOS: An

  4. MRI analysis of vascular compressive trigeminal neuralgia

    International Nuclear Information System (INIS)

    Tang Ling; Chai Weimin; Song Qi; Ling Huawei; Miao Fei; Chen Kemin

    2006-01-01

    Objective: To analyze the offending vessels of vascular compressive trigeminal neuralgia by magnetic resonance tomographic angiography (MRTA). Methods: MRTA images of 235 asymptomatic trigeminal nerves and 147 symptomatic trigeminal nerves were analyzed by two radiologists who were blinded to the clinical findings. Judgment was made on if there were some vessels close to the trigeminal nerve. The diameter of the offending vessel, the distance from the offending vessel's contact point to the pons and the direction of the vessel toward the nerve were also recorded at the same time. Group t-test and Chi-Square test were used for statistics. Results: Two hundred and forty-two trigeminal nerves of all 382 nerves can be detected offending vessels on MRTA images, 111 of 242 trigeminal nerves were asymptomatic, the rest 131 were symptomatic. Statistical analysis indicated that the distance from the offending vessel's contact point to the pons in symptomatic group (the median is 2 mm) was shorter than that in the asymptomatic group (the median is 4 mm) (P<0.01). In 89.3% cases (117/131) of the symptomatic group the angle between the vessel and the nerve is larger than 45 degree, but only in 67.6% cases (75/111) in the asymptomatic group the angle is larger than 45 degree. That means significant difference is between the two groups (P<0.01). Vessel-nerve compression can be seen in 1 case of asymptomatic group (0.4%, 1/235) and 45 eases in symptomatic group (30.6%, 45/147). The vessel-nerve compression rate of the symptomatic group was much higher than that of the asymptomatic group (P<0.01). Conclusion: MR is a useful tool to evaluate the offending vessels of vascular compressive trigeminal neuralgia. The distance from the offending vessel's contact point to the pons and the direction of the vessel toward the nerve are related to the onset of vascular compressive trigeminal neuralgia. (authors)

  5. Vascular type Ehlers-Danlos syndrome is associated with platelet dysfunction and low vitamin D serum concentration.

    Science.gov (United States)

    Busch, Albert; Hoffjan, Sabine; Bergmann, Frauke; Hartung, Birgit; Jung, Helena; Hanel, Daniela; Tzschach, Andeas; Kadar, Janos; von Kodolitsch, Yskert; Germer, Christoph-Thomas; Trobisch, Heiner; Strasser, Erwin; Wildenauer, René

    2016-08-03

    The vascular type represents a very rare, yet the clinically most fatal entity of Ehlers-Danlos syndrome (EDS). Patients are often admitted due to arterial bleedings and the friable tissue and the altered coagulation contribute to the challenge in treatment strategies. Until now there is little information about clotting characteristics that might influence hemostasis decisively and eventually worsen emergency situations. 22 vascular type EDS patients were studied for hemoglobin, platelet volume and count, Quick and activated partial thromboplastin time, fibrinogen, factor XIII, von Willebrand disease, vitamin D and platelet aggregation by modern standard laboratory methods. Results show a high prevalence of over 50 % for platelet aggregation disorders in vascular type EDS patients, especially for collagen and epinephrine induced tests, whereas the plasmatic cascade did not show any alterations. Additionally, more than half of the tested subjects showed low vitamin D serum levels, which might additionally affect vascular wall integrity. The presented data underline the importance of detailed laboratory screening methods in vascular type EDS patients in order to allow for targeted application of platelet-interacting substances that might be of decisive benefit in the emergency setting.

  6. Fabrication of triple-layered bifurcated vascular scaffold with a certain degree of three-dimensional structure

    Science.gov (United States)

    Liu, Yuanyuan; Jiang, Weijian; Yang, Yang; Pu, Huayan; Peng, Yan; Xin, Liming; Zhang, Yi; Sun, Yu

    2018-01-01

    Constructing vascular scaffolds is important in tissue engineering. However, scaffolds with characteristics such as multiple layers and a certain degree of spatial morphology still cannot be readily constructed by current vascular scaffolds fabrication techniques. This paper presents a three-layered bifurcated vascular scaffold with a curved structure. The technique combines 3D printed molds and casting hydrogel and fugitive ink to create vessel-mimicking constructs with customizable structural parameters. Compared with other fabrication methods, the technique can create more native-like 3D geometries. The diameter and wall thickness of the fabricated constructs can be independently controlled, providing a feasible approach for vascular scaffold construction. Enzymatically-crosslinked gelatin was used as the scaffold material. The morphology and mechanical properties were evaluated. Human umbilical cord derived endothelial cells (HUVECs) were seeded on the scaffolds and cultured for 72 h. Cell viability and morphology were assessed. The results showed that the proposed process had good application potentials, and will hopefully provide a feasible approach for constructing vascular scaffolds.

  7. VASCULAR INJURIES IN TEHRAN: A REVIEW OF 123 CASES

    Directory of Open Access Journals (Sweden)

    M. Karbakhsh M. R. Zarei

    2006-09-01

    Full Text Available Abstract- Studies of the epidemiology of civilian vascular trauma in developing countries are rather few. This is a prospective study of our experience with vascular trauma in a referral university hospital in Tehran, Iran. The aim was to study the etiology, pattern of injuries and the mortality and morbidity rates due to vascular trauma in our population. In this cross-sectional study, all trauma patients suspicious of having vascular injuries who were admitted to Sina Hospital between March 2002 and May 2003 were included. Among 123 studied cases, there were 109 males and 14 females.Blunt injuries were more common than penetrating ones (56.1% vs. 43.9%. The most common anatomical site of vascular injuries had been knee and lower leg. In fact, cases with lower extremities vascular trauma were twice as common as those with vascular trauma in upper limbs (59.1% vs. 27.3%. The commonest injured vessels were popliteal artery followed by femoral artery. Arterial repair with graft interposition was done in 23 cases and bypass graft in 13 cases. Procedures on veins were performed in 24 cases. Five patients (4.06% died and in 3 cases the patients died because of non-vascular reasons. The present study allows an understanding of the epidemiology of vascular trauma in the one of the major trauma centers in the metropolitan city of Tehran. The majority of our cases were young males sustaining vascular injuries due to road traffic accidents or being stabbed with knives. It also has important implications for vascular injury prevention in our community.

  8. Vascular Plants of the Hanford Site

    International Nuclear Information System (INIS)

    Sackschewsky, Michael R.; Downs, Janelle L.

    2001-01-01

    This report provides an updated listing of the vascular plants present on and near the U.S. Department of Energy Hanford Site. This document is an update of a listing of plants prepared by Sackschewdky et al. in 1992. Since that time there has been a significant increase in the botanical knowledge of the Hanford Site. The present listing is based on an examination of herbarium collections held at PNNL, at WSU-Tri Cities, WSU-Pullman, Brigham Young University, and The University of Washington, and on examination of ecological literature derived from the Hanford and Benton county areas over the last 100 years. Based on the most recent analysis, there are approximately 725 different plant species that have been documented on or around the Hanford Site. This represents an approximate 20% increase in the number of species reported within Sackschewsky et al. (1992). This listing directly supports DOE and contractor efforts to assess the potential impacts of Hanford Site operations

  9. Hemothorax in vascular Ehlers-Danlos syndrome.

    Science.gov (United States)

    Álvarez, Kevin; Jordi, López; Jose Angel, Hernández

    2017-10-16

    Vascular Ehlers-Danlos syndrome (EDS IV) is a rare genetic disorder characterized by an alteration in the COL3A1 gene which encodes type III collagen. It is the most common type of collagen in vessels of medium size and certain organs such as the intestines and the uterus. The alteration of this type of collagen produces aneurisms and ruptures of vessels and organs. A high level of clinical suspicion is required for diagnosis. It is a complex disease whose management requires a multidisciplinary team to treat the different complications that may occur. We report the case of a 50-year-old man diagnosed with EDS IV detected incidentally after hemothorax secondary to a coughing spell. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.

  10. Subclinical pulmonary involvement in collagen vascular diseases

    International Nuclear Information System (INIS)

    Dansin, E.; Wallaert, B.; Jardin, M.R.; Remy, J.; Hatron, P.Y.; Tonnel, A.B.

    1990-01-01

    A recruitment of immune and inflammatory cells into alveolar spaces has been reported in patients with collagen vascular diseases (CVD) and a normal chest radiograph. These findings defined the concept of subclinical alveolitis (SCA). To determine whether SCA may be associated with CT signs of interstitial lung disease (ILD), the authors of this paper compared bronchoalveolar lavage (BAL) findings and high-resolution (HRCT) scans in 36 patients with CVD and normal chest radiographs (systemic sclerosis [SS, n = 21], rheumatoid arthritis [RA, n = 9], primary Sjogren's syndrome [PS, n = 6]). HRCT scans were obtained in supine and prone positions. Results of BAL revealed SCA in 17/36 patients (47%); lymphocyte SCA in 4/36 (24%); neutrophil SCA in 7/36 (41%); and mixed SCA in 6/36 (35%)

  11. Gait and Equilibrium in Subcortical Vascular Dementia

    Directory of Open Access Journals (Sweden)

    Rita Moretti

    2011-01-01

    Full Text Available Subcortical vascular dementia is a clinical entity, widespread, even challenging to diagnose and correctly treat. Patients with this diagnosis are old, frail, often with concomitant pathologies, and therefore, with many drugs in therapy. We tried to diagnose and follow up for three years more than 600 patients. Study subjects were men and women, not bedridden, aged 68–94 years, outpatients, recruited from June, 1st 2007 to June, 1st 2010. We examined them clinically, neurologically, with specific consideration on drug therapies. Our aim has been to define gait and imbalance problem, if eventually coexistent with the pathology of white matter and/or with the worsening of the deterioration. Drug intake interference has been detected and considered.

  12. Diabetic Retinopathy: Vascular and Inflammatory Disease

    Science.gov (United States)

    Semeraro, F.; Cancarini, A.; dell'Omo, R.; Rezzola, S.; Romano, M. R.; Costagliola, C.

    2015-01-01

    Diabetic retinopathy (DR) is the leading cause of visual impairment in the working-age population of the Western world. The pathogenesis of DR is complex and several vascular, inflammatory, and neuronal mechanisms are involved. Inflammation mediates structural and molecular alterations associated with DR. However, the molecular mechanisms underlying the inflammatory pathways associated with DR are not completely characterized. Previous studies indicate that tissue hypoxia and dysregulation of immune responses associated with diabetes mellitus can induce increased expression of numerous vitreous mediators responsible for DR development. Thus, analysis of vitreous humor obtained from diabetic patients has made it possible to identify some of the mediators (cytokines, chemokines, and other factors) responsible for DR pathogenesis. Further studies are needed to better understand the relationship between inflammation and DR. Herein the main vitreous-related factors triggering the occurrence of retinal complication in diabetes are highlighted. PMID:26137497

  13. Skeletal Myocyte Types and Vascularity in the Black Sicilian Pig

    Directory of Open Access Journals (Sweden)

    S. Velotto

    2007-01-01

    Full Text Available The objective of this study was to verify the presence of giant fibres in the Black Sicilian pig skeletal muscle and to evaluate the effect of sex on histochemical and morphometric characteristics of the myocytes (myofibres as well as vascularity of the muscle. Twenty Black Sicilian pigs (10 males, 10 females from a farm in Sicily (Italy were slaughtered at two years of age. Muscle tissues were obtained from three muscles: psoas major, longissimus dorsi, and trapezius. Myofibres were stained for myosin ATPase, succinic dehydrogenase, and α-amylase-PAS. For all fibre types, area and perimeter were measured. Slow-twitch oxidative fibres, fast-twitch glycolytic fibres and fast-twitch oxidative-glycolytic fibres were histochemically differentiated; an image-analyzing system was used. The results showed no differences between males and females in percentage of the fibre types, but there were significant differences between sexes in size of all the three fibre types. Psoas major muscle had a high percentage of slow-twitch oxidative fibres and contained more capillaries per fibre and per mm2 than trapezius and longissimus dorsi, in which fast-twitch glycolytic fibres dominated. The cross-sectional area of all fibres types was larger in longissimus dorsi than in trapezius and psoas major muscles; the giant fibres were absent in all the muscles studied. Fibre type composition may contribute to the variation of meat quality.

  14. Telemedicine in vascular surgery: clinical experience in a single centre.

    Science.gov (United States)

    Robaldo, Alessandro; Rousas, Nikolaos; Pane, Bianca; Spinella, Giovanni; Palombo, Domenico

    2010-01-01

    Over a three-year period we performed 630 carotid endarterectomy procedures in 588 patients. From these we selected 90 patients (group A) who fulfilled the criteria for discharge one day after surgery. These patients were given an electronic blood pressure meter, a video phone for use at home and an antihypertensive drug (amlodipine). Using web-based video conferencing, we monitored the patients every 4 hours for the first two days. The other 498 patients (group B) were discharged on the second postoperative day. There were no significant differences between the groups in demographic characteristics, risk factors, carotid lesions, operative time, postoperative complications or blood loss. No cervical hematomas developed in group A. No patients needed to be readmitted because of major complications relating to the carotid endarterectomy. During the video-communication, 28 patients (31%) with a hypertensive crisis were treated by administration of amlodipine. At discharge, a questionnaire showed that there was a feeling of insecurity in both groups: 87% in group A vs. 79% in group B (P > 0.05). In group A, insecurity decreased after the first video connection and disappeared after the 8th day postoperatively. Telemedicine appears feasible and useful in carotid endarterectomy and may have other applications in vascular surgery care.

  15. Improved FPGA controlled artificial vascular system for plethysmographic measurements

    Directory of Open Access Journals (Sweden)

    Laqua Daniel

    2016-09-01

    Full Text Available The fetal oxygen saturation is an important parameter to determine the health status of a fetus, which is until now mostly acquired invasively. The transabdominal, fetal pulse oximetry is a promising approach to measure this non-invasively and continuously. The fetal pulse curve has to be extracted from the mixed signal of mother and fetus to determine its oxygen saturation. For this purpose efficient algorithms are necessary, which have to be evaluated under constant and reproducable test conditions. This paper presents the improved version of a phantom which can generate artificial pulse waves in a synthetic tissue phantom. The tissue phantom consists of several layers that mimic the different optical properties of the fetal and maternal tissue layers. Additionally an artificial vascular system and a dome, which mimics the bending of the belly of a pregnant woman, are incorporated. To obtain data on the pulse waves, several measurement methods are included, to help understand the behavior of the signals gained from the pulse waves. Besides pressure sensors and a transmissive method we integrated a capacitive approach, that makes use of the so called “Pin Oscillator” method. Apart from the enhancements in the tissue phantom and the measurements, we also improved the used blood substitute, which reproduces the different absorption characteristics of fetal and maternal blood. The results show that the phantom can generate pulse waves similar to the natural ones. Furthermore, the phantom represents a reference that can be used to evaluate the algorithms for transabdominal, fetal pulse oximetry.

  16. Age-specific association between blood pressure and vascular and non-vascular chronic diseases in 0·5 million adults in China: a prospective cohort study

    Directory of Open Access Journals (Sweden)

    Ben Lacey, FFPH

    2018-06-01

    Full Text Available Summary: Background: The age-specific association between blood pressure and vascular disease has been studied mostly in high-income countries, and before the widespread use of brain imaging for diagnosis of the main stroke types (ischaemic stroke and intracerebral haemorrhage. We aimed to investigate this relationship among adults in China. Methods: 512 891 adults (59% women aged 30–79 years were recruited into a prospective study from ten areas of China between June 25, 2004, and July 15, 2008. Participants attended assessment centres where they were interviewed about demographic and lifestyle characteristics, and their blood pressure, height, and weight were measured. Incident disease was identified through linkage to local mortality records, chronic disease registries, and claims to the national health insurance system. We used Cox regression analysis to produce adjusted hazard ratios (HRs relating systolic blood pressure to disease incidence. HRs were corrected for regression dilution to estimate associations with long-term average (usual systolic blood pressure. Findings: During a median follow-up of 9 years (IQR 8–10, there were 88 105 incident vascular and non-vascular chronic disease events (about 90% of strokes events were diagnosed using brain imaging. At ages 40–79 years (mean age at event 64 years [SD 9], usual systolic blood pressure was continuously and positively associated with incident major vascular disease throughout the range 120–180 mm Hg: each 10 mm Hg higher usual systolic blood pressure was associated with an approximately 30% higher risk of ischaemic heart disease (HR 1·31 [95% CI 1·28–1·34] and ischaemic stroke (1·30 [1·29–1·31], but the association with intracerebral haemorrhage was about twice as steep (1·68 [1·65–1·71]. HRs for vascular disease were twice as steep at ages 40–49 years than at ages 70–79 years. Usual systolic blood pressure was also positively associated with incident

  17. Findings of computed tomography in vascular Parkinsonism

    International Nuclear Information System (INIS)

    Tomura, Noriaki; Tamakawa, Yoshiharu; Kato, Toshio; Yamada, Shigeru; Hirota, Koichi.

    1985-01-01

    In order to evaluate the ventricular size, we measured the following A-F. A: The ratio of the ventricle-caudate nucleus distance to the maximum transverse inner diameter of skull on 4.0 cm above orbitomeatal plane. B: The ratio of the largest width of the anterior horn of the lateral ventricle to the maximum transverse inner diameter on the same level as A. C: The ratio of the maximum width of the third ventricle to the maximum transverse inner diameter of skull on the same level as A. D: The ratio of the minimal width of both cellae mediae to the maximum transverse inner diameter on 6.0 cm above orbitomeatal plane. E: The ratio of the area of both the anterior horn to the intracranial area on the same level as A. F: The ratio of the area of both the body of the lateral ventricle to the intracranial area on the same level as D. C was only statistically significant compared with controls. The enlargement of cerebral cortical sulci in patients was more prominent than that in controls. The degree of periventricular lucency in patients was more severe than that in controls. The number of small low density area in basal ganglia in patients was more than that in controls. The pathogenesis of periventricular lucency in the patients with vascular Parkinsonism differs from that in the patients with obstructive hydrocephalus. The periventricular area corresponds to border zone in the arterial angioarchitecture in the brain, therefore, the periventricular area undergoes easily ischemic changes than the other area. It is thought that the periventricular lucency in vascular Parkinsonism is due to the infarction, softening, vacuoles etc, and reflects the cerebrovascular arteriosclerosis. Furthermore, in view of the correlation between CT findings and clinical symptoms, the periventricular lucency reflects well the clinical severity. (J.P.N.)

  18. Vascular measurements correlate with estrogen receptor status

    International Nuclear Information System (INIS)

    Lloyd, Mark C; Alfarouk, Khalid O; Verduzco, Daniel; Bui, Marilyn M; Gillies, Robert J; Ibrahim, Muntaser E; Brown, Joel S; Gatenby, Robert A

    2014-01-01

    Breast carcinoma can be classified as either Estrogen Receptor (ER) positive or negative by immunohistochemical phenotyping, although ER expression may vary from 1 to 100% of malignant cells within an ER + tumor. This is similar to genetic variability observed in other tumor types and is generally viewed as a consequence of intratumoral evolution driven by random genetic mutations. Here we view cellular evolution within tumors as a classical Darwinian system in which variations in molecular properties represent predictable adaptations to spatially heterogeneous environmental selection forces. We hypothesize that ER expression is a successful adaptive strategy only if estrogen is present in the microenvironment. Since the dominant source of estrogen is blood flow, we hypothesized that, in general, intratumoral regions with higher blood flow would contain larger numbers of ER + cells when compared to areas of low blood flow and in turn necrosis. This study used digital pathology whole slide image acquisition and advanced image analysis algorithms. We examined the spatial distribution of ER + and ER- cells, vascular density, vessel area, and tissue necrosis within histological sections of 24 breast cancer specimens. These data were correlated with the patients ER status and molecular pathology report findings. ANOVA analyses revealed a strong correlation between vascular area and ER expression and between high fractional necrosis and absent ER expression (R 2 = 39%; p < 0.003 and R 2 = 46%; p < 0.001), respectively). ER expression did not correlate with tumor grade or size. We conclude that ER expression can be understood as a Darwinian process and linked to variations in estrogen delivery by temporal and spatial heterogeneity in blood flow. This correlation suggests strategies to promote intratumoral blood flow or a cyclic introduction of estrogen in the treatment schedule could be explored as a counter-intuitive approach to increase the efficacy of anti

  19. Estimation of vascular spaces using radiolabeled erythrocytes

    International Nuclear Information System (INIS)

    Nasseri, K.

    2002-01-01

    Measurement of vascular volume is important in many physiological and pathological studies. For isolated organ preparations, this is usually performed using normal erythrocytes (red blood cell; RBC) and in the whole body studies, labeled RBCs are used. The aim of the present project was to compare the two methods in model organ (the liver) in terms of sensitivity and packed RBCs are suspended in normal saline. 100 u l aliquot is injected into the portal vein of rat. The outflow samples collected, hemo lysed and measured by colorimeter. In the second method, the packed RBCs are incubated with Cr-sodium and then resuspended in normal saline. A bolus of labelled RBCs with known activity is injected into portal vein of rats and the outflow activity is determined by gamma spectrometry. The extend of Cr binding to RBCs was investigated; in all experiments less than 2% of the total radioactivity after washing was extra cellular. Both methods were tested in 30 preparations. The normalized frequency outflow profiles of RBCs counted by two methods were then compared. The standard curves of the two methods were also obtained and the correlation was compared. The shape of the curves and calculated vascular volume obtained from the two methods were similar. A good correlation was observed between the methods of measurement of RBCs. The results indicated the second method is more precise and sensitive to low grade changes while the first method is quicker and better preserves RBCs than the second method. Theses advantages, together with safety considerations, favour the first method when it is applicable

  20. Vascular factors in suspected normal pressure hydrocephalus

    Science.gov (United States)

    Agerskov, Simon; Rabiei, Katrin; Marlow, Thomas; Jensen, Christer; Guo, Xinxin; Kern, Silke; Wikkelsø, Carsten; Skoog, Ingmar

    2016-01-01

    Objective: We examined clinical and imaging findings of suspected idiopathic normal pressure hydrocephalus (iNPH) in relation to vascular risk factors and white matter lesions (WMLs), using a nested case-control design in a representative, population-based sample. Methods: From a population-based sample, 1,235 persons aged 70 years or older were examined with CT of the brain between 1986 and 2000. We identified 55 persons with hydrocephalic ventricular enlargement, i.e., radiologic findings consistent with iNPH. Among these, 26 had clinical signs that fulfilled international guideline criteria for probable iNPH. These cases were labeled suspected iNPH. Each case was matched to 5 controls from the same sample, based on age, sex, and study cohort. Data on risk factors were obtained from clinical examinations and the Swedish Hospital Discharge Register. History of hypertension, diabetes mellitus (DM), smoking, overweight, history of coronary artery disease, stroke/TIA, and WMLs on CT were examined. Risk factors associated with iNPH with a p value <0.1 in χ2 tests were included in conditional logistic regression models. Results: In the regression analyses, suspected iNPH was related to moderate to severe WMLs (odds ratio [OR] 5.2; 95% confidence interval [CI]: 1.5–17.6), while hydrocephalic ventricular enlargement was related to hypertension (OR 2.7; 95% CI: 1.1–6.8), moderate to severe WMLs (OR 6.5; 95% CI: 2.1–20.3), and DM (OR 4.3; 95% CI: 1.1–16.3). Conclusions: Hypertension, WMLs, and DM were related to clinical and imaging features of iNPH, suggesting that vascular mechanisms are involved in the pathophysiology. These findings might have implications for understanding disease mechanisms in iNPH and possibly prevention. PMID:26773072

  1. A simple tissue model for practicing ultrasound guided vascular ...

    African Journals Online (AJOL)

    Introduction: The use of ultrasound in anaesthetic practice continues to be more established and the use of ultrasound guidance in establishing vascular access is recommended by various groups. We have developed a tissue model for the practice and skills development in ultrasound vascular access. Method: The tissue ...

  2. Inferior vena cava leiomyosarcoma: vascular reconstruction is not ...

    African Journals Online (AJOL)

    ... vena cava is a rare and aggressive tumor, arising from the smooth muscle cells in the vessel wall. A large complete surgical resection is the essential treatment. The need of vascular reconstruction is not always mandatory. It's above all to understand the place of the reconstruction with artificial vascular patch prosthetics of ...

  3. Vascular access complications and risk factors in hemodialysis ...

    African Journals Online (AJOL)

    Vascular access complications and risk factors in hemodialysis patients: A single center study. ... Stenosis was the most common risk factor for vascular failure as it occurred in (29%) of patients. ... Other risk factors for dialysis CRBSI include older age, low serum albumin, high BUN and decreasing the duration of dialysis.

  4. Inapparent pulmonary vascular disease in an ex-heroin user

    International Nuclear Information System (INIS)

    Antonelli Incalzi, R.; Ludovico Maini, C.; Giuliano Bonetti, M.; Campioni, P.; Pistelli, R.; Fuso, L.

    1986-01-01

    A severe pulmonary vascular derangement, usually reported in drug addicts, was diagnosed in a 28-year-old asymptomatic ex-heroin user by means of fortuitously performed pulmonary perfusion imaging. Neither physical findings nor pulmonary function tests, aroused suspicion of the diagnosis. A search for asymptomatic pulmonary vascular disease probably should be undertaken in drug addicts

  5. Convergent evolution of vascular optimization in kelp (Laminariales).

    Science.gov (United States)

    Drobnitch, Sarah Tepler; Jensen, Kaare H; Prentice, Paige; Pittermann, Jarmila

    2015-10-07

    Terrestrial plants and mammals, although separated by a great evolutionary distance, have each arrived at a highly conserved body plan in which universal allometric scaling relationships govern the anatomy of vascular networks and key functional metabolic traits. The universality of allometric scaling suggests that these phyla have each evolved an 'optimal' transport strategy that has been overwhelmingly adopted by extant species. To truly evaluate the dominance and universality of vascular optimization, however, it is critical to examine other, lesser-known, vascularized phyla. The brown algae (Phaeophyceae) are one such group--as distantly related to plants as mammals, they have convergently evolved a plant-like body plan and a specialized phloem-like transport network. To evaluate possible scaling and optimization in the kelp vascular system, we developed a model of optimized transport anatomy and tested it with measurements of the giant kelp, Macrocystis pyrifera, which is among the largest and most successful of macroalgae. We also evaluated three classical allometric relationships pertaining to plant vascular tissues with a diverse sampling of kelp species. Macrocystis pyrifera displays strong scaling relationships between all tested vascular parameters and agrees with our model; other species within the Laminariales display weak or inconsistent vascular allometries. The lack of universal scaling in the kelps and the presence of optimized transport anatomy in M. pyrifera raises important questions about the evolution of optimization and the possible competitive advantage conferred by optimized vascular systems to multicellular phyla. © 2015 The Author(s).

  6. Macrophage migration inhibitory factor induces vascular leakage via autophagy

    Directory of Open Access Journals (Sweden)

    Hong-Ru Chen

    2015-01-01

    Full Text Available Vascular leakage is an important feature of acute inflammatory shock, which currently has no effective treatment. Macrophage migration inhibitory factor (MIF is a pro-inflammatory cytokine that can induce vascular leakage and plays an important role in the pathogenesis of shock. However, the mechanism of MIF-induced vascular leakage is still unclear. In this study, using recombinant MIF (rMIF, we demonstrated that MIF induced disorganization and degradation of junction proteins and increased the permeability of human endothelial cells in vitro. Western blotting analysis showed that rMIF treatment induced LC3 conversion and p62 degradation. Inhibition of autophagy with a PI3K inhibitor (3-MA, a ROS scavenger (NAC or autophagosomal-lysosomal fusion inhibitors (bafilomycin A1 and chloroquine rescued rMIF-induced vascular leakage, suggesting that autophagy mediates MIF-induced vascular leakage. The potential involvement of other signaling pathways was also studied using different inhibitors, and the results suggested that MIF-induced vascular leakage may occur through the ERK pathway. In conclusion, we showed that MIF triggered autophagic degradation of endothelial cells, resulting in vascular leakage. Inhibition of MIF-induced autophagy may provide therapeutic targets against vascular leakage in inflammatory shock.

  7. The development of a reflective vascular training portfolio: Using a ...

    African Journals Online (AJOL)

    ... of formative assessment to certify candidates. Case-based self-reflection in postgraduate training may be used as an additional educational tool and incorporated into the curricula vitae of trainees. We describe the method used to assess a vascular case, based on a self-reflective training method (vascular case portfolio).

  8. Subclinical hypothyroidism ups the risk of vascular complications in ...

    African Journals Online (AJOL)

    Subclinical hypothyroidism ups the risk of vascular complications in type 2 diabetes. ... hypothyroidism (SCH) and vascular complications of type 2 diabetes. ... However, gender (p = 0.076), BMI (p = 0.092), and smoking (P = 0.715) were not ...

  9. 64-MDCT angiography of blunt vascular injuries of the neck.

    Science.gov (United States)

    Chokshi, Falgun H; Munera, Felipe; Rivas, Luis A; Henry, Robert P; Quencer, Robert M

    2011-03-01

    CT angiography (CTA) using 64-MDCT enables timely evaluation of injuries associated with blunt neck trauma. The purpose of this article is to familiarize the reader with the most frequent CTA signs of blunt vascular injury. CTA is a valuable tool to detect blunt vascular injuries, especially using its multiplanar and 3D reconstruction capabilities.

  10. Arborescent vascular dilatation mimicking Lichtenberg figures from lightning.

    Science.gov (United States)

    Tempark, Therdpong; Iwasaki, Julie; Shwayder, Tor

    2014-01-01

    The clinical presentation of arborizing vascular dilatation can resemble Lichtenberg figures from lightning. Both have a feather-like or ferning pattern. We report an interesting case of pressure-induced vasodilatation (PIV) caused by temporary vascular occlusion from jeans buttons. © 2014 Wiley Periodicals, Inc.

  11. Major lipids, apolipoproteins, and risk of vascular disease

    DEFF Research Database (Denmark)

    Collaboration, Emerging Risk Factors; Di Angelantonio, Emanuele; Sarwar, Nadeem

    2009-01-01

    CONTEXT: Associations of major lipids and apolipoproteins with the risk of vascular disease have not been reliably quantified. OBJECTIVE: To assess major lipids and apolipoproteins in vascular risk. DESIGN, SETTING, AND PARTICIPANTS: Individual records were supplied on 302,430 people without...

  12. Diagnosis and treatment of vascular damage in dementia

    NARCIS (Netherlands)

    Biessels, GJ

    2016-01-01

    This paper provides an overview of cognitive impairment due to vascular brain damage, which is referred to as vascular cognitive impairment (VCI). Over the past decades, we have seen marked progress in detecting VCI, both through maturation of diagnostic concepts and through advances in brain

  13. Radiation-induced vascular lesions of the skin: an overview

    NARCIS (Netherlands)

    Flucke, U.E.; Requena, L.; Mentzel, T.

    2013-01-01

    Radiation-induced cutaneous vascular neoplasms occur infrequently and comprise benign, so-called atypical vascular lesions (AVL) and angiosarcomas (AS), often being high-grade malignant tumors. Both arise most frequently within previously irradiated skin in breast-conserving-treated mammary cancer

  14. colour-flow ultrasound in the detection of penetrating vascular

    African Journals Online (AJOL)

    To determine the sensitivity of colour-flow ultrasound in the detection of penetrating vascular injuries of ... Colour-flow ultrasound is sensitive in detecting vascular injuries and is suitable as a screening .... injury, ultrasound appears to be sensitive in detecting these lesions. However there is a risk of missing more central.

  15. How do bryophytes govern generative recruitment of vascular plants?

    NARCIS (Netherlands)

    Soudzilovskaia, N.A.; Graae, B.J.; Douma, J.C.; Grau, O.; Milbau, A.; Shevtsova, A.; Wolters, L.; Cornelissen, J.H.C.

    2011-01-01

    Interactions between vascular plants and bryophytes determine plant community composition in many ecosystems. Yet, little is known about the importance of interspecific differences between bryophytes with respect to their effects on vascular plants. We compared the extent to which species-specific

  16. Childhood Vascular Tumors Treatment (PDQ®)—Health Professional Version

    Science.gov (United States)

    Vascular tumors in children are a spectrum of diseases that includes infantile, congenital, spindle cell and epithelioid hemangiomas, as well as angiofibromas, hemangioendotheliomas, and angiosarcomas. Get detailed information about the many types of vascular tumors including clinical presentation, diagnosis, prognosis and treatment in this summary for clinicians.

  17. Anti-Inflammatory Effects of Interleukin-19 in Vascular Disease

    Directory of Open Access Journals (Sweden)

    Ross N. England

    2012-01-01

    Full Text Available Despite aggressive dietary modification, lipid-lowering medications, and other interventional medical therapy, vascular disease continues to be a leading cause of mortality in the western world. It is a significant medical and socioeconomic problem contributing to mortality of multiple diseases including myocardial infarction, stroke, renal failure, and peripheral vascular disease. Morbidity and mortality of vascular disease are expected to worsen with the increasing number of patients with comorbid conditions such as obesity, metabolic syndrome, and diabetes mellitus type 2. Vascular diseases such as atherosclerosis, restenosis, and allograft vasculopathy are recognized to be driven by inflammation, and as such, cytokines which mediate inflammation not only represent important targets of rational therapy, but also can be considered as possible therapeutic modalities themselves. In this paper, we will examine the role of inflammatory cytokines and lymphocyte Th1/Th2 polarity in vascular inflammation, with a focus on atherosclerotic vascular disease. We will then introduce a recently described Th2 interleukin, interleukin-19 (IL-19, as a previously unrecognized mediator of vascular inflammatory disorders. We will review our current understanding of this interleukin in health and disease and present the possibility that IL-19 could represent a potential therapeutic to combat vascular inflammatory disease.

  18. Insertional mutagenesis in the vascular wilt pathogen Verticillium dahliae

    NARCIS (Netherlands)

    Santhanam, P.

    2014-01-01

    Vascular wilt diseases caused by soil-borne pathogens are among the most

    devastating plant diseases worldwide. The ascomycete fungus Verticillium dahliae

    causes vascular wilt diseases in hundreds of dicotyledonous plant species, including

    important crops such as eggplant,

  19. Individualized Vascular Disease Prevention in High-Risk Patients

    NARCIS (Netherlands)

    Kaasenbrood, L

    2016-01-01

    In the pharmacologic prevention of vascular events, clinicians need to translate average effects from a clinical trial to the individual patient. Prediction models can contribute to individualized vascular disease prevention by selecting patients for treatment based on estimated risk or expected

  20. Novel strategies to improve the patency of vascular prostheses

    NARCIS (Netherlands)

    Heyligers, J.M.M.

    2006-01-01

    Two novel strategies to improve the patency of vascular prostheses are described in this thesis. To improve the outcome of synthetic vascular bypass surgery, cell seeding is a promising concept that has extensively been investigated and is still evolving. To improve the short term effects due to