Mejia, Christian R; Verastegui-Díaz, Araseli; Quiñones-Laveriano, Dante M; Aranzabal-Alegría, Germán; Failoc-Rojas, Virgilio E
Determinar la frecuencia de actividad física y su asociación con enfermedades crónicas en ancianos de 11 ciudades del Perú. Se realizó un estudio transversal analítico de datos secundarios. La variable dependiente fue la no realización de actividad física, y las independientes fueron las enfermedades crónicas y otras variables fisioantropométricas. Para el análisis bivariado y multivariado se usaron los modelos lineales generalizados. Se consideró un nivel de confianza del 95% y un valor de p < 0.05 como estadísticamente significativo. De los 1030 ancianos, el 68% (698) no realizaba actividad física. Con el modelo multivariado se obtuvo que, por cada año de edad, aumentaba un 1.5% la frecuencia no hacer actividad física (razón de prevalencia ajustada [RPa]: 1.015; intervalo de confianza del 95% [IC 95%]: 1.006-1.024; p = 0.001); por cada centímetro de cintura adicional, disminuía un 0.6% la realización de actividad física (RPa: 0.994; IC 95%: 0.992-0.997; p < 0.001); y aquellos que padecían otra enfermedad cardiaca crónica (RPa: 1.15; IC 95%:1.02-1.30; p = 0.019) tenían mayores frecuencias de no realizar actividad física, ajustado por el sexo y por la ciudad de residencia. El no realizar actividad física se asoció con padecer alguna enfermedad cardiaca, mayor edad y el perímetro de cintura. Es necesario tener en cuenta estos resultados para promover la actividad física en esta población. To determine the frequency of physical activity and its association with chronic diseases in the elderly in eleven cities of Peru. A cross-sectional study of secondary data was conducted; the dependent variable was not the realization of physical activity, chronic disease and other physio-anthropometric variables were independent variables. For bivariate and multivariate analysis generalized linear models were used. A confidence level of 95% and p < 0.05 as statistically significant was considered. Of the 1030 elderly 68% (698) did not perform physical
Gracia-Ramos, Abraham Edgar; Cruz-Domínguez, María del Pilar; Vera-Lastra, Olga Lidia
Introducción: la enfermedad de Castleman es un trastorno linfoproliferativo atípico en el que pueden existir manifestaciones compatibles con síndrome POEMS. Caso clínico: hombre de 53 años de edad con antecedente de diabetes mellitus tipo 2, hipotiroidismo y enfermedad de Addison. Se iniciaron parestesias y debilidad en las extremidades y, posteriormente, disnea, endurecimiento cutáneo, fenómeno de Raynaud y pérdida de peso. Se identificó taquipnea, hiperpigmentación cutánea generalizada y extremidades con endurecimiento cutáneo, debilidad muscular, hipoestesia e hiporreflexia; así como hiperprolactinemia, testosterona baja, hipotiroidismo y enfermedad de Addison; los anticuerpos antinucleares y antiScl-70 fueron negativos. Los potenciales evocados somatosensoriales indicaron neuropatía periférica y la electromiografía, olineuropatía axonal severa. Radiografía torácica: infiltrado reticular bilateral y ensanchamiento mediastinal. Electrocardiograma: hipertensión arterial pulmonar moderada. Tomografía toracoabdominal: ganglios axilares, mediastinales y retroperitoneales. Con la biopsia se identificó enfermedad de Castleman multicéntrica hialina vascular. El paciente recibió rituximab. Conclusiones: si bien la experiencia con el rituximab aún es limitada, en el caso descrito se observó buena respuesta.
Existe evidencia suficiente para declarar a la tuberculosis como enfermedad ocupacional en diversos profesionales especialmente entre los trabajadores de salud. En el Perú están normados y reglamentados los derechos laborales inherentes a la tuberculosis como enfermedad ocupacional, como la cobertura por discapacidad temporal o permanente. Sin embargo, estos derechos aún no han sido suficientemente socializados. En este trabajo se presenta información sobre el riesgo de adquirir tuberculosis en el lugar de trabajo, se revisan las evidencias para declarar a la tuberculosis como enfermedad ocupacional en trabajadores de salud y se presenta la legislación peruana vigente al respecto. PMID:22858771
... Contact Us Vascular Disease What is Vascular Disease? Education and Awareness Vascular Diseases Abdominal Aortic Aneurysm Aortic Dissection Arteriovenous Malformation Atherosclerosis Buerger's Disease Carotid Artery Disease ...
Becker, James T.
Introducción y desarrollo En los próximos 50 años vamos a presenciar un incremento significativo de la población mayor de 65 años y por lo tanto va a aumentar, considerablemente, el número de individuos con riesgo de desarrollar demencias neurodegenerativas, especialmente la enfermedad de Alzheimer (EA). Las estrategias actuales de tratamiento farmacológico y no farmacológico se han centrado en las fases sintomáticas de esta enfermedad y, gradualmente, vamos teniendo una mayor comprensión de los posibles factores de riesgo del síndrome clínico. Conclusiones Los estudios de neuroimagen han sido muy útiles para mostrar los cambios estructurales del envejecimiento normal y patológico, así como también los factores de riesgo para la EA. Los tratamientos apropiados de los factores de riesgo y su posible combinación con tratamientos específicos para la EA podrían prolongar el período presintomático de la EA y, por tanto, mejorar la calidad de vida y disminuir la carga para el paciente, la familia y la sociedad. PMID:20517866
The vascular system is the body's network of blood vessels. It includes the arteries, veins and capillaries that carry ... to and from the heart. Problems of the vascular system are common and can be serious. Arteries ...
Jiménez-Caballero, Pedro E; López-Espuela, Fidel; Portilla-Cuenca, Juan C; Jiménez-Gracia, M Antonia; Casado-Naranjo, Ignacio
Introduccion. Existe una serie de factores de riesgo cerebrovascular modificables, como son la hipertension arterial, la diabetes mellitus, dislipidemias y la fibrilacion auricular, cuyo reconocimiento y control es fundamental para disminuir la aparicion de enfermedades cerebrovasculares. En ocasiones, el ictus puede ser el sintoma de presentacion de estos factores de riesgo. Pacientes y metodos. Estudio observacional prospectivo de los pacientes que ingresan en la unidad de ictus de nuestro hospital por enfermedad cerebrovascular aguda –accidente isquemico transitorio e ictus isquemico– para conocer el porcentaje de pacientes con hipertension arterial, diabetes mellitus, dislipidemias y fibrilacion auricular no diagnosticadas previamente. Resultados. Se selecciono a 186 pacientes, de los que 24 presentaban hipertension arterial no conocida (12,9%); 11, diabetes mellitus no conocida (5,9%); 49, hipercolesterolemia no conocida (26,3%); 15, hipertrigliceridemia no conocida (8,1%), y 22 tenian fibrilacion auricular no conocida (11,8%). En total, 96 pacientes (51,6%) tenian alguno de estos factores de riesgo cerebrovascular. La existencia de un factor de riesgo no diagnosticado previamente era mayor en el medio rural, en los sujetos que no habian fallecido a los seis meses y en los ataques isquemicos transitorios respecto a los ictus isquemicos. Conclusiones. Mas de la mitad de los sujetos que sufren un evento cerebrovascular tienen un factor de riesgo que no se ha diagnosticado previamente. Se deben realizar campanas para implementar la deteccion de estos factores, asi como incidir en el control de estos para disminuir la aparicion y recidiva de patologia vascular.
... a Hand Surgeon? What is a Hand Therapist? Media Find a Hand Surgeon Home Anatomy Vascular Disorders Email to a friend * required fields From * To * DESCRIPTION Vascular disorders are problems with arteries and veins. Arteries are pipes that bring oxygen-rich blood from the heart to the fingers. Veins ...
In this review paper introduction of new technologies in vascular surgery is discussed. The difficulties compared to introduction of pharmacological treatment are analyzed. Pros and cons with randomized controlled trials and observational studies are listed.
Backer, Carl L; Mongé, Michael C; Popescu, Andrada R; Eltayeb, Osama M; Rastatter, Jeffrey C; Rigsby, Cynthia K
The term vascular ring refers to congenital vascular anomalies of the aortic arch system that compress the esophagus and trachea, causing symptoms related to those two structures. The most common vascular rings are double aortic arch and right aortic arch with left ligamentum. Pulmonary artery sling is rare and these patients need to be carefully evaluated for frequently associated tracheal stenosis. Another cause of tracheal compression occurring only in infants is the innominate artery compression syndrome. In the current era, the diagnosis of a vascular ring is best established by CT imaging that can accurately delineate the anatomy of the vascular ring and associated tracheal pathology. For patients with a right aortic arch there recently has been an increased recognition of a structure called a Kommerell diverticulum which may require resection and transfer of the left subclavian artery to the left carotid artery. A very rare vascular ring is the circumflex aorta that is now treated with the aortic uncrossing operation. Patients with vascular rings should all have an echocardiogram because of the incidence of associated congenital heart disease. We also recommend bronchoscopy to assess for additional tracheal pathology and provide an assessment of the degree of tracheomalacia and bronchomalacia. The outcomes of surgical intervention are excellent and most patients have complete resolution of symptoms over a period of time. Copyright © 2016 Elsevier Inc. All rights reserved.
Sepulveda, Abel; Buchanan, Edward P.
Vascular anomalies are divided into two main groups: tumors and malformations. Vascular tumors are a large and complex group of lesions, especially for clinicians with none or little experience in this field. In the past, these lesions caused a great deal of confusion because many appear analogous to the naked eye. Thankfully, recent advances in diagnostic techniques have helped the medical community to enhance our comprehension, accurately label, diagnose, and treat these lesions. In this article, we will review the most frequent vascular tumors and provide the reader with the tools to properly label, diagnose, and manage these complex lesions. PMID:25045329
... dementia is a general term describing problems with reasoning, planning, judgment, memory and other thought processes caused ... dementia. Whether a stroke affects your thinking and reasoning depends on your stroke's severity and location. Vascular ...
... ultrasound uses sound waves to evaluate the body’s circulatory system and help identify blockages in the arteries and ... is a useful way of evaluating the body's circulatory system. Vascular ultrasound is performed to: help monitor the ...
... patient to vascular research and care. It combines digital health tools for people to manage their own health with online education and communities, and improves communication between doctors, patients ...
... ultrasound uses sound waves to evaluate the body’s circulatory system and help identify blockages and detect blood clots. ... is a useful way of evaluating the body's circulatory system. Vascular ultrasound is performed to: help monitor the ...
... Stanton BF, St Geme JW, Schor NF. Other congenital heart and vascular malformations. In: Kliegman RM, Stanton BF, St Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, ... AN. Congenital heart disease. In: Mann DL, Zipes DP, Libby ...
... Contact Us Vascular Disease What is Vascular Disease? Education and Awareness Vascular Diseases Abdominal Aortic Aneurysm Aortic Dissection Arteriovenous Malformation Atherosclerosis Buerger's Disease Carotid Artery Disease ...
... Contact Us Vascular Disease What is Vascular Disease? Education and Awareness Vascular Diseases Abdominal Aortic Aneurysm Aortic Dissection Arteriovenous Malformation Atherosclerosis Buerger's Disease Carotid Artery Disease ...
Korczyn, Amos D; Vakhapova, Veronika; Grinberg, Lea T
The epidemic grow of dementia causes great concern for the society. It is customary to consider Alzheimer’s disease (AD) as the most common cause of dementia, followed by vascular dementia (VaD). This dichotomous view of a neurodegenerative disease as opposed to brain damage caused by extrinsic factors led to separate lines of research in these two entities. Indeed, accumulated data suggest that the two disorders have additive effects and probably interact; however it is still unknown to what degree. Furthermore, epidemiological studies have shown “vascular” risk factors to be associated with AD. Therefore, a clear distinction between AD and VaD cannot be made in most cases, and is furthermore unhelpful. In the absence of efficacious treatment for the neurodegenerative process, special attention must be given to vascular component, even in patients with presumed mixed pathology. Symptomatic treatment of VaD and AD are similar, although the former is less effective. For prevention of dementia it is important to treat aggressively all factors, even in stroke survivors who do not show evidence of cognitive decline,. In this review, we will give a clinical and pathological picture of the processes leading to VaD and discuss it interaction with AD. PMID:22575403
Nagy, Janice A.; Benjamin, Laura; Zeng, Huiyan; Dvorak, Ann M.
The vascular system has the critical function of supplying tissues with nutrients and clearing waste products. To accomplish these goals, the vasculature must be sufficiently permeable to allow the free, bidirectional passage of small molecules and gases and, to a lesser extent, of plasma proteins. Physiologists and many vascular biologists differ as to the definition of vascular permeability and the proper methodology for its measurement. We review these conflicting views, finding that both provide useful but complementary information. Vascular permeability by any measure is dramatically increased in acute and chronic inflammation, cancer, and wound healing. This hyperpermeability is mediated by acute or chronic exposure to vascular permeabilizing agents, particularly vascular permeability factor/vascular endothelial growth factor (VPF/VEGF, VEGF-A). We demonstrate that three distinctly different types of vascular permeability can be distinguished, based on the different types of microvessels involved, the composition of the extravasate, and the anatomic pathways by which molecules of different size cross-vascular endothelium. These are the basal vascular permeability (BVP) of normal tissues, the acute vascular hyperpermeability (AVH) that occurs in response to a single, brief exposure to VEGF-A or other vascular permeabilizing agents, and the chronic vascular hyperpermeability (CVH) that characterizes pathological angiogenesis. Finally, we list the numerous (at least 25) gene products that different authors have found to affect vascular permeability in variously engineered mice and classify them with respect to their participation, as far as possible, in BVP, AVH and CVH. Further work will be required to elucidate the signaling pathways by which each of these molecules, and others likely to be discovered, mediate the different types of vascular permeability. PMID:18293091
Ye, Zheng-Hua; Freshour, Glenn; Hahn, Michael G; Burk, David H; Zhong, Ruiqin
Vascular tissues, xylem and phloem, form a continuous network throughout the plant body for transport of water, minerals, and food. Characterization of Arabidopsis mutants defective in various aspects of vascular formation has demonstrated that Arabidopsis is an ideal system for investigating the molecular mechanisms controlling vascular development. The processes affected in these mutants include initiation or division of procambium or vascular cambium, formation of continuous vascular cell files, differentiation of procambium or vascular cambium into vascular tissues, cell elongation, patterned secondary wall thickening, and biosynthesis of secondary walls. Identification of the genes affected by some of these mutations has revealed essential roles in vascular development for a cytokinin receptor and several factors mediating auxin transport or signaling. Mutational studies have also identified a number of Arabidopsis mutants defective in leaf venation pattern or vascular tissue organization in stems. Genetic evidence suggests that the vascular tissue organization is regulated by the same positional information that determines organ polarity.
Ursache, Robertas; Heo, Jung-Ok; Helariutta, Ykä
About 200 researchers from around the world attended the Third International Conference on Plant Vascular Biology (PVB 2013) held in July 2013 at the Rantapuisto Conference Center, in Helsinki, Finland (http://www.pvb2013.org). The plant vascular system, which connects every organ in the mature plant, continues to attract the interest of researchers representing a wide range of disciplines, including development, physiology, systems biology, and computational biology. At the meeting, participants discussed the latest research advances in vascular development, long- and short-distance vascular transport and long-distance signalling in plant defence, in addition to providing a context for how these studies intersect with each other. The meeting provided an opportunity for researchers working across a broad range of fields to share ideas and to discuss future directions in the expanding field of vascular biology. In this report, the latest advances in understanding the mechanism of vascular trafficking presented at the meeting have been summarized.
Gibbons, C P
Primary vascular access is usually achievable by a distal autogenous arterio-venous fistula (AVF). This article describes the approach to vascular access planning, the usual surgical options and the factors affecting patency.
... Certification with this new online course from the Society for Vascular Medicine. Learn more. Looking for a ... jobs are listed right now. Copyright © 2016 The Society for Vascular Medicine. All Rights Reserved.
... designed for long-term use include the arteriovenous (AV) fistula and the AV graft. A third type of vascular access—the ... term use. What is an arteriovenous fistula? An AV fistula is a connection, made by a vascular ...
Wang, Yunbing; Zhang, Xingdong
This article describes the evolution of minimally invasive intervention technologies for vascular restoration therapy from early-stage balloon angioplasty in 1970s, metallic bare metal stent and metallic drug-eluting stent technologies in 1990s and 2000s, to bioresorbable vascular scaffold (BVS) technology in large-scale development in recent years. The history, the current stage, the challenges and the future of BVS development are discussed in detail as the best available approach for vascular restoration therapy. The criteria of materials selection, design and processing principles of BVS, and the corresponding clinical trial results are also summarized in this article. PMID:26816624
Wang, Yunbing; Zhang, Xingdong
This article describes the evolution of minimally invasive intervention technologies for vascular restoration therapy from early-stage balloon angioplasty in 1970s, metallic bare metal stent and metallic drug-eluting stent technologies in 1990s and 2000s, to bioresorbable vascular scaffold (BVS) technology in large-scale development in recent years. The history, the current stage, the challenges and the future of BVS development are discussed in detail as the best available approach for vascular restoration therapy. The criteria of materials selection, design and processing principles of BVS, and the corresponding clinical trial results are also summarized in this article.
Ohashi-Ito, Kyoko; Fukuda, Hiroo
The initiation of vascular development occurs during embryogenesis and the development of lateral organs, such as lateral roots and leaves. Understanding the mechanism underlying the initiation of vascular development has been an important goal of plant biologists. Auxin flow is a crucial factor involved in the initiation of vascular development. In addition, recent studies have identified key factors that regulate the establishment of vascular initial cells in embryos and roots. In this review, we summarize the recent findings in this field and discuss the initiation of vascular development.
Levin, Laura E; Lauren, Christine T
Multifocal vascular lesions are important to recognize and appropriately diagnose. Generally first noticed on the skin, multifocal vascular lesions may have systemic involvement. Distinguishing among the different types of multifocal vascular lesions is often based on clinical features; however, radiological imaging and/or biopsy are frequently needed to identify distinct features and guide treatment. Knowledge of the systemic associations that can occur with different vascular anomalies may reduce life-threatening complications, such as coagulopathy, bleeding, cardiac compromise, and neurologic sequelae. This review provides a synopsis of the epidemiology, pathogenesis, presentation, workup, and treatment of several well-recognized multifocal vascular tumors and malformations.
Nguyen, Tuyet A.; Krakowski, Andrew C.; Naheedy, John H.; Kruk, Peter G.
Vascular anomalies are commonly encountered in pediatric and dermatology practices. Most of these lesions are benign and easy to diagnose based on history and clinical exam alone. However, in some cases the diagnosis may not be clear. This may be of particular concern given that vascular anomalies may occasionally be associated with an underlying syndrome, congenital disease, or serious, life-threatening condition. Defining the type of vascular lesion early and correctly is particularly important to determine the optimal approach to management and treatment of each patient. The care of pediatric patients often requires collaboration from a multitude of specialties including pediatrics, dermatology, plastic surgery, radiology, ophthalmology, and neurology. Although early characterization of vascular lesions is important, consensus guidelines regarding the evaluation and imaging of vascular anomalies does not exist to date. Here, the authors provide an overview of pediatric vascular lesions, current classification systems for characterizing these lesions, the various imaging modalities available, and recommendations for appropriate imaging evaluation. PMID:26705446
Dichgans, Martin; Leys, Didier
Cerebrovascular disease typically manifests with stroke, cognitive impairment, or both. Vascular cognitive impairment refers to all forms of cognitive disorder associated with cerebrovascular disease, regardless of the specific mechanisms involved. It encompasses the full range of cognitive deficits from mild cognitive impairment to dementia. In principle, any of the multiple causes of clinical stroke can cause vascular cognitive impairment. Recent work further highlights a role of microinfarcts, microhemorrhages, strategic white matter tracts, loss of microstructural tissue integrity, and secondary neurodegeneration. Vascular brain injury results in loss of structural and functional connectivity and, hence, compromise of functional networks within the brain. Vascular cognitive impairment is common both after stroke and in stroke-free individuals presenting to dementia clinics, and vascular pathology frequently coexists with neurodegenerative pathology, resulting in mixed forms of mild cognitive impairment or dementia. Vascular dementia is now recognized as the second most common form of dementia after Alzheimer's disease, and there is increasing awareness that targeting vascular risk may help to prevent dementia, even of the Alzheimer type. Recent advances in neuroimaging, neuropathology, epidemiology, and genetics have led to a deeper understanding of how vascular disease affects cognition. These new findings provide an opportunity for the present reappraisal of vascular cognitive impairment. We further briefly address current therapeutic concepts.
Mottet, B; Aptel, F; Geiser, M; Romanet, J P; Chiquet, C
The exact pathophysiology of glaucoma is not fully understood. Understanding of the vascular pathophysiology of glaucoma requires: knowing the techniques for measuring ocular blood flow and characterizing the topography of vascular disease and the mechanisms involved in this neuropathy. A decreased mean ocular perfusion pressure and a loss of vascular autoregulation are implicated in glaucomatous disease. Early decrease in ocular blood flow has been identified in primary open-angle glaucoma and normal pressure glaucoma, contributing to the progression of optic neuropathy. The vascular damage associated with glaucoma is present in various vascular territories within the eye (from the ophthalmic artery to the retina) and is characterized by a decrease in basal blood flow associated with a dysfunction of vasoregulation.
Krishnamurthy, Ganesh Keller, Marc S.
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.
Santhanam, Lakshmi; Christianson, David W.; Nyhan, Daniel; Berkowitz, Dan E.
Vascular and associated ventricular stiffness is one of the hallmarks of the aging cardiovascular system. Both an increase in reactive oxygen species production and a decrease in nitric oxide (NO) bioavailability contribute to the endothelial dysfunction that underlies this vascular stiffness, independent of other age-related vascular pathologies such as atherosclerosis. The activation/upregulation of arginase appears to be an important contributor to age-related endothelial dysfunction by a mechanism that involves substrate (l-arginine) limitation for NO synthase (NOS) 3 and therefore NO synthesis. Not only does this lead to impaired NO production but also it contributes to the enhanced production of reactive oxygen species by NOS. Although arginase abundance is increased in vascular aging models, it appears that posttranslational modification by S-nitrosylation of the enzyme enhances its activity as well. The S-nitrosylation is mediated by the induction of NOS2 in the endothelium. Furthermore, arginase activation contributes to aging-related vascular changes by mechanisms that are not directly related to changes in NO signaling, including polyamine-dependent vascular smooth muscle proliferation and collagen synthesis. Taken together, arginase may represent an as yet elusive target for the modification of age-related vascular and ventricular stiffness contributing to cardiovascular morbidity and mortality. PMID:18719233
Vascular anomalies are divided in two major categories: tumours (such as infantile hemangiomas) and malformations. Hemangiomas are common benign neoplasms that undergo a proliferative phase followed by stabilization and eventual spontaneous involution, whereas vascular malformations are rare structural anomalies representing morphogenetic errors of developing blood vessels and lymphatics. It is important to properly diagnose vascular anomalies early in childhood because of their distinct differences in morbidity, prognosis and need for a multidisciplinary management. We discuss a number of characteristic clinical features as clues for early diagnosis and identification of associated syndromes.
Spence, Lisa A; Weaver, Connie M
Recent research has reported a possible link between calcium supplementation and increased risk of cardiovascular disease and its endpoints in healthy, older adults. To evaluate the current evidence regarding the impact of calcium supplementation on cardiovascular disease risk and to address research gaps, the present review was conducted. Systematic reviews and meta-analyses were included, when available, along with original articles. The articles included in the review were obtained from PubMed using the following search terms: calcium intake, calcium supplementation, cardiovascular disease, myocardial infarction, mortality, and vascular calcification. The majority of the studies reviewed demonstrated no statistically significant adverse or beneficial effect of calcium supplementation on cardiovascular disease or its endpoints. While some studies indicate a possible increased risk, there is a lack of consensus on these findings and a need exists to further elucidate a mechanism. More experimental data are necessary to understand the impact of calcium intake, both levels and sources, on vascular calcification and vascular disease. The use of (41)C kinetic modeling in the Ossabaw swine provides an approach for assessing soft tissue calcification in an atherosclerotic and normal state to address research gaps.
Vijayakumar, Abhishek; Srinivas, Amruthashree; Chandrashekar, Babitha Moogali; Vijayakumar, Avinash
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
Cox, Joshua A.; Bartlett, Erica; Lee, Edward I.
Identification and treatment of vascular malformations is a challenging endeavor for physicians, especially given the great concern and anxiety created for patients and their families. The goal of this article is to provide a review of vascular malformations, organized by subtype, including capillary, venous, lymphatic and arteriovenous malformations. Only by developing a clear understanding of the clinical aspects, diagnostic tools, imaging modalities, and options for intervention will appropriate care be provided and results maximized. PMID:25045330
Mangiarotti, G; Cesano, G; Thea, A; Hamido, D; Pacitti, A; Segoloni, G P
Availability of a proper vascular access is a basic condition for a proper extracorporeal replacement in end-stage chronic renal failure. However, biological factors, management and other problems, may variously condition their middle-long term survival. Therefore, personal experience of over 25 years has been critically reviewed in order to obtain useful information. In particular "hard" situations necessitating complex procedures have been examined but, if possible, preserving the peripherical vascular features.
Torsney, Evelyn; Xu, Qingbo
Homeostasis of the vessel wall is essential for maintaining its function, including blood pressure and patency of the lumen. In physiological conditions, the turnover rate of vascular cells, i.e. endothelial and smooth muscle cells, is low, but markedly increased in diseased situations, e.g. vascular injury after angioplasty. It is believed that mature vascular cells have an ability to proliferate to replace lost cells normally. On the other hand, recent evidence indicates stem/progenitor cells may participate in vascular repair and the formation of neointimal lesions in severely damaged vessels. It was found that all three layers of the vessels, the intima, media and adventitia, contain resident progenitor cells, including endothelial progenitor cells, mesenchymal stromal cells, Sca-1+ and CD34+ cells. Data also demonstrated that these resident progenitor cells could differentiate into a variety of cell types in response to different culture conditions. However, collective data were obtained mostly from in vitro culture assays and phenotypic marker studies. There are many unanswered questions concerning the mechanism of cell differentiation and the functional role of these cells in vascular repair and the pathogenesis of vascular disease. In the present review, we aim to summarize the data showing the presence of the resident progenitor cells, to highlight possible signal pathways orchestrating cell differentiation toward endothelial and smooth muscle cells, and to discuss the data limitations, challenges and controversial issues related to the role of progenitors. This article is part of a special issue entitled, "Cardiovascular Stem Cells Revisited".
Czihal, Michael; Banafsche, Ramin; Hoffmann, Ulrich; Koeppel, Thomas
Dealing with vascular compression syndromes is one of the most challenging tasks in Vascular Medicine practice. This heterogeneous group of disorders is characterised by external compression of primarily healthy arteries and/or veins as well as accompanying nerval structures, carrying the risk of subsequent structural vessel wall and nerve damage. Vascular compression syndromes may severely impair health-related quality of life in affected individuals who are typically young and otherwise healthy. The diagnostic approach has not been standardised for any of the vascular compression syndromes. Moreover, some degree of positional external compression of blood vessels such as the subclavian and popliteal vessels or the celiac trunk can be found in a significant proportion of healthy individuals. This implies important difficulties in differentiating physiological from pathological findings of clinical examination and diagnostic imaging with provocative manoeuvres. The level of evidence on which treatment decisions regarding surgical decompression with or without revascularisation can be relied on is generally poor, mostly coming from retrospective single centre studies. Proper patient selection is critical in order to avoid overtreatment in patients without a clear association between vascular compression and clinical symptoms. With a focus on the thoracic outlet-syndrome, the median arcuate ligament syndrome and the popliteal entrapment syndrome, the present article gives a selective literature review on compression syndromes from an interdisciplinary vascular point of view.
Mishwani, Ahmad Hussain; Ghaffar, Abdul; Janjua, Sarfaraz
To determine the frequency and pattern of different types of vascular injuries, their management and surgical complications. Case series. Combined Military Hospital, Peshawar, from August 2008 to August 2010. All patients of vascular injuries were included. Traumatic amputation, amputation for extensive soft tissue, or nerve injury, death due to reasons other than vascular injuries or Mangled Extremity Severity Score (MESS > 7) were excluded from study. Data included patient profile, time and date of admission, place, site, type and mechanism of injury, associated injuries, vital signs, treatment, type of vascular repair and outcome. Decision to operate was mainly based on clinical diagnosis and hand-held Doppler finding. There were 170 vascular injuries in 96 patients; 76.4% were arterial and 23.5% were venous. Gunshot wounds was main cause (54%) and extremities were the commonest site (85%). Arteries were repaired in 87% and veins in 40% cases. Venous interposition graft was the preferred method of repair. The overall limb salvage rate was 95%. Thrombosis and infection of the graft and repair were the main causes of secondary amputation. Haemorrhage, reperfusion injury and infection were the main causes of death. Every effort should be made to repair an injured artery to preserve a limb and life. Tourniquet, prophylactic fasciotomy and vascular shunts play an important role. Management of life threatening injuries, unstable fracture of long bones and debridement before definitive repair of artery is important.
Bielli, Alessandra; Scioli, Maria Giovanna; Mazzaglia, Donatella; Doldo, Elena; Orlandi, Augusto
Oxygen free radicals and other reactive oxygen species (ROS) are common products of normal aerobic cellular metabolism, but high levels of ROS lead to oxidative stress and cellular damage. Increased production of ROS favors vascular dysfunction, inducing altered vascular permeability and inflammation, accompanied by the loss of vascular modulatory function, the imbalance between vasorelaxation and vasoconstriction, and the aberrant expression of inflammatory adhesion molecules. Inflammatory stimuli promote oxidative stress generated from the increased activity of mitochondrial nicotinamide adenine dinucleotide phosphate oxidase, particularly of the Nox4 isoform, with the consequent impairment of mitochondrial β-oxidation. Vascular dysfunction due to the increase in Nox4 activity and ROS overproduction leads to the progression of cardiovascular diseases, diabetes, inflammatory bowel disease, and neurological disorders. Considerable research into the development of effective antioxidant therapies using natural derivatives or new synthetic molecules has been conducted. Antioxidants may prevent cellular damage by reducing ROS overproduction or interfering in reactions that involve ROS. Vitamin E and ascorbic acid are well known as natural antioxidants that counteract lipid peroxidative damage by scavenging oxygen-derived free radicals, thus restoring vascular function. Recently, preliminary studies on natural antioxidants such as goji berries, thymus, rosemary, green tea ginseng, and garlic have been conducted for their efficacy in preventing vascular damage. N-acetyl-cysteine and propionyl-L-carnitine are synthetic compounds that regulate ROS production by replacing endogenous antioxidants in both endothelial and smooth muscle cells. In this review, we consider the molecular mechanisms underlying the generation of oxidative stress-induced vascular dysfunction as well as the beneficial effects of antioxidant therapies.
Hendrickx, Benoit; Vranckx, Jan J; Luttun, Aernout
Providing a blood-vascular network to promote survival and integration of cells in thick dermal substitutes for application in full-thickness wounds is essential for the successful outcome of skin tissue engineering. Nevertheless, promoting vascularization also represents a critical bottleneck in today's skin tissue engineering practice. Several cell types have been considered and tested, mostly in preclinical studies, to increase vascularization. When the clinical situation allows delayed reconstruction of the defect, an autologous approach is preferable, whereas in acute cases allogeneic therapy is needed. In both cases, the cells should be harvested with minimal donor-site morbidity and should be available in large amounts and safe in terms of tumor formation and transmission of animal diseases. Here, we outline the different mechanisms of cell-based vascularization and subsequently elaborate in more detail on the candidate cell types and their pros and cons in terms of clinical application and regulation of the wound healing process.
Tumanova, U N; Shchegolev, A I
The paper gives the data available in the literature on vascularization of hepatocellular carcinoma (HCC). Sinusoidal capillarization and unpaired arteries are shown to play an important role in the development and progression of HCC. The density of microvessels detected by immunohistochemical techniques is a morphological indicator of the degree of angiogenic processes. Higher-grade HCC is followed by changes in its vascularization and concurrent with a progressive increase in the proportion of blood entering along the hepatic artery. The morphological indicators of microvessel density are recommended to use as addi- tional criteria for determining the prognosis of the disease, designing targeted anti-angiogenic drugs, and evaluating the efficiency of performed therapy.
Tanaka, Yoshiya; Okada, Yosuke
Recent progress in basic research has revealed certain similarities between processes of bone calcification and calcifications of vascular tissues which contribute to several cardiovascular diseases. Bisphosphonates, which are inhibitors of bone resorption that are widely used to treat osteoporosis, also inhibit cholesterol biosynthesis, differentiation of macrophage to foam cell, differentiation of smooth muscle cells to osteoblast-like cells in certain stimuli during calcification processes of vessels. These findings extend the link between bone remodeling and vascular calcification, opening perspectives toward novel therapeutic strategies, however, current evidence is not conclusive and further research is necessary to confirm these actions in the clinical setting.
Nojiri, C; Senshu, K; Okano, T
Although many synthetic vascular grafts have been developed and evaluated experimentally or clinically, none of them have met long-term patency when applied as a small diameter vascular substitute. We have recently developed a small caliber vascular graft (3 mm i.d.) using a nonthrombogenic polymer coating. The graft consists of three layered structures: Dacron for the outer layer, polyurethane in the middle layer, and a HEMA/styrene block copolymer (HEMA-st) coating for the inner layer. HEMA-st is an amphiphilic block copolymer composed of 2-hydroxyethyl methacrylate and styrene which has demonstrated improved blood compatibility over existing biomedical polymers in both in vitro and ex vivo experiments. Ten grafts were evaluated in a dog bilateral carotid replacement model. The grafts were electively retrieved at 7, 14, 30, 92, and 372 days after implantation. All grafts were patent without detectable thrombi along the graft length including anastomotic sites. Scanning electron micrographs of retrieved graft lumen showed fairly clean surfaces covered with a homogenous protein-like layer without microthrombi or endothelial cell lining. The thickness of the surface protein layer measured by a transmission electron microscopy was what can be described as monolayer protein adsorption regardless of implantation periods of as much as 372 days. A stable monolayer adsorbed protein layer formed on HEMA-st surfaces demonstrated nonthrombogenic activities in vivo and secure long-term patency of small caliber vascular grafts with the absence of an endothelial cell lining.
Appleton, Jason P; Scutt, Polly; Sprigg, Nikola; Bath, Philip M
Vascular dementia (VaD) is the second commonest cause of dementia. Stroke is the leading cause of disability in adults in developed countries, the second major cause of dementia and the third commonest cause of death. Traditional vascular risk factors-diabetes, hypercholesterolaemia, hypertension and smoking-are implicated as risk factors for VaD. The associations between cholesterol and small vessel disease (SVD), stroke, cognitive impairment and subsequent dementia are complex and as yet not fully understood. Similarly, the effects of lipids and lipid-lowering therapy on preventing or treating dementia remain unclear; the few trials that have assessed lipid-lowering therapy for preventing (two trials) or treating (four trials) dementia found no evidence to support the use of lipid-lowering therapy for these indications. It is appropriate to treat those patients with vascular risk factors that meet criteria for lipid-lowering therapy for the primary and secondary prevention of cardiovascular and cerebrovascular events, and in line with current guidelines. Managing the individual patient in a holistic manner according to his or her own vascular risk profile is recommended. Although the paucity of randomized controlled evidence makes for challenging clinical decision making, it provides multiple opportunities for on-going and future research, as discussed here. © 2017 The Author(s).
... may be done to diagnose, monitor or treat diseases of the circulatory and vascular system include: Cardiac CT for calcium scoring Cardiac MRI ... Cardiac rehabilitation is therapy used to prevent heart disease from getting worse. It is usually recommended after major heart-related events such ... Boateng S, Sanborn T. ...
Boon, Laurence M.; Ballieux, Fanny; Vikkula, Miikka
Vascular anomalies are localized defects of vascular development. Most of them occur sporadically, i.e. there is no familial history of lesions, yet in a few cases clear inheritance is observed. These inherited forms are often characterized by multifocal lesions that are mainly small in size and increase in number with patient’s age. On the basis of these inherited forms, molecular genetic studies have unraveled a number of inherited mutations giving direct insight into the pathophysiological cause and the molecular pathways that are implicated. Genetic defects have been identified for hereditary haemorrhagic telangiectasia (HHT), inherited cutaneomucosal venous malformation (VMCM), glomuvenous malformation (GVM), capillary malformation - arteriovenous malformation (CM-AVM), cerebral cavernous malformation (CCM) and some isolated and syndromic forms of primary lymphedema. We focus on these disorders, the implicated mutated genes and the underlying pathogenic mechanisms. We also call attention to the concept of Knudson’s double-hit mechanism to explain incomplete penetrance and the large clinical variation in expressivity of inherited vascular anomalies. This variability renders the making of correct diagnosis of the rare inherited forms difficult. Yet, the identification of the pathophysiological causes and pathways involved in them has had an unprecedented impact on our thinking of their etiopathogenesis, and has opened the doors towards a more refined classification of vascular anomalies. It has also made it possible to develop animal models that can be tested for specific molecular therapies, aimed at alleviating the dysfunctions caused by the aberrant genes and proteins. PMID:21095468
The management of vascular amputees in the Roehampton Limb Surgery Unit since its opening in 1975 is outlined and the results in 167 cases presented. Of the 35 patients over the age of 80, 57% were walking independently at the time of their discharge from the unit. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:7377693
Struszczyk, Marcin H; Bednarek, Paweł; Raczyński, Krzysztof
Polyethyleneterephthalate (PET), and to a lesser extent Teflon have become the major synthetic grafting material. Unlike nylon, Ivalon, and Vinyon-N which lose their tensile strength after implantation, PET and Teflon remain essentially unchanged even after long periods. TRICOMED S.A. produces the family of the knitted vascular implants Dallon made from PET fibres including: Dallon, Dallon H, Tricogel. Both Dallon and Dallon H are manufactured in a form of double (external and internal) velour surface using multifilament yarn and having optimal graft design (a variety of sizes and lengths). The velour surface gives the surface a velvety, plush texture, which improves tissue in--growth. Moreover, Dallon H is a unique vascular prostheses showing the increase in the blood susceptibility that is useful for 4 times less blood demand during preclotting as compared with standard prosthesis. Tricogel graft is made of thin-wall prostheses sealed with the porcine gelatin that provides intraoperative tightness (without preclotting) and the optimal healing process. Hydrophilic behavior of the graft is observed as an instant moistening of the surface with patient's blood and as sweating. The blood stream does not dissolve nor washes away the gelatin but causes the gelatin film to swell, which makes a better tightness. The work will describe the properties of manmade vascular grafts as well as their applications in the vascular surgery.
Xu, Junyan; Shi, Guo-Ping
Extracellular matrix proteins form the basic structure of blood vessels. Along with providing basic structural support to blood vessels, matrix proteins interact with different sets of vascular cells via cell surface integrin or non-integrin receptors. Such interactions induce vascular cell de novo synthesis of new matrix proteins during blood vessel development or remodeling. Under pathological conditions, vascular matrix proteins undergo proteolytic processing, yielding bioactive fragments to influence vascular wall matrix remodeling. Vascular cells also produce alternatively spliced variants that induce vascular cell production of different matrix proteins to interrupt matrix homeostasis, leading to increased blood vessel stiffness; vascular cell migration, proliferation, or death; or vascular wall leakage and rupture. Destruction of vascular matrix proteins leads to vascular cell or blood-borne leukocyte accumulation, proliferation, and neointima formation within the vascular wall; blood vessels prone to uncontrolled enlargement during blood flow diastole; tortuous vein development; and neovascularization from existing pathological tissue microvessels. Here we summarize discoveries related to blood vessel matrix proteins within the past decade from basic and clinical studies in humans and animals — from expression to cross-linking, assembly, and degradation under physiological and vascular pathological conditions, including atherosclerosis, aortic aneurysms, varicose veins, and hypertension. PMID:25045854
Gómez-Duarte, Oscar G.
Resumen Las cepas de E. coli patógenas intestinales son causas importantes de la enfermedad diarreica aguda (EDA) en niños menores de 5 años en América Latina, África y Asia y están asociadas a alta mortalidad en niños en las comunidades más pobres de África y el Sudeste Asiático. Estudios sobre el papel de las E. coli patógenas intestinales en la EDA infantil en Colombia y otros países de América Latina son limitados debido a la carencia de ensayos para detección de estos patógenos en los laboratorios clínicos de centros de salud. Estudios recientes han reportado la detección de E. coli patógenas intestinales en Colombia, siendo la E. coli enterotoxigénica la cepa más frecuentemente asociada a diarrea en niños menores de 5 años. Otros patógenos detectados en estos pacientes incluyen las E. coli enteroagregativa, enteropatógena, productora de toxina Shiga, y de adherencia difusa. Con base en estudios que reportan la presencia de E. coli productora de toxina Shiga y E. coli enteroagregativa en carnes y vegetales en supermercados, se cree que productos alimentarios contaminados contribuyen a la transmisión de estos patógenos y a la infección del huésped susceptible. Más estudios son necesarios para evaluar los mecanismos de transmisión, el impacto en la epidemiologia de la EDA, y las pautas de manejo y prevención de estos patógenos que afectan la población pediátrica en Colombia. PMID:25491457
Okafor, Chidi; Kalantarinia, Kambiz
The success of therapeutic apheresis (TA), similar to hemodialysis, depends on the integrity of the extracorporeal circuit as well as a reliable vascular access. However, unlike hemodialysis, which requires high flow of blood around 400 mL/minute through the extracorporeal circuit for effective clearance, TA is usually carried out with much lower blood flow rates (<100 ml/minute). Therefore, even peripheral venous access can be considered for TA. The main determinants of the choice of vascular access for TA is the duration of the planned treatment and, to a certain degree, the indication for its use. While peripheral venous access and temporary central venous catheters are sufficient for short-term TA, tunnelled catheters and arteriovenous fistulae (AVF) are usually used for long-term treatments. Because of the large body of evidence in the hemodialysis literature on the advantages of AVF over tunnelled catheters and AV grafts, they should be considered as the preferred access for chronic TA as well. However, advance planning for the care of AVF after creation is of critical importance especially since many of the healthcare providers dealing with TA are less familiar with caring for AVF than nephrologists and dialysis nurses. In this article we first review the similarities and differences between HD and TA procedures. The pros and cons of different vascular access options are discussed next. Finally, we have included a list of recommendations on maintenance of AVF created for TA based on our own experience.
Callcut, Rachael A; Mell, Matthew W
Early diagnosis and intervention are paramount for improving the likelihood of a favorable outcome for traumatic vascular injuries. As technology has rapidly diversified, the diagnostic and therapeutic approaches available for vascular injuries have evolved. Mortality and morbidity from vascular injury have declined over the last decade. The use of vascular shunts and tourniquets has become standard of care in military medicine. Copyright © 2013 Elsevier Inc. All rights reserved.
Kalva, Sanjeeva P; Mueller, Peter R
Though a myriad of vascular conditions affect the elderly, atherosclerosis remains the most common vascular disorder, followed by venous thromboembolism and varicose veins. In this article, the authors discuss the imaging of atherosclerosis affecting various vascular territories and pay special attention to the elderly population. The authors also discuss imaging findings of segmental arterial mediolysis, giant cell arteritis, and venous thromboembolism.
Rands, Gianetta; Orrell, Martin
Background Aspirin is widely prescribed for patients with a diagnosis of vascular dementia. In a survey of UK geriatricians and psychiatrists 80% of patients with clinical diagnoses of vascular dementia were prescribed aspirin. However, a number of queries remain unanswered. Is there convincing evidence that aspirin benefits patients with vascular dementia? Does aspirin affect cognition and behaviour, or improve prognosis? Does the risk of cerebral or gastric haemorrhage outweigh any benefit? Objectives To assess the randomised trial evidence for efficacy and safety of aspirin in the treatment of vascular dementia. Search methods We searched ALOIS: the Cochrane Dementia and Cognitive Improvement Group’s Specialized Register on 12 March 2012 using the terms: aspirin OR “acetylsalicylic acid”. ALOIS contains records of clinical trials identified from monthly searches of a number of major healthcare databases, numerous trial registries and grey literature sources. In addition, relevant websites were searched and some journals were handsearched. Specialists in the field were approached for unpublished material and any publications found were searched for additional references. Selection criteria Randomised controlled trials investigating the effect of aspirin for vascular dementia were eligible for inclusion. Data collection and analysis Retrieved studies were analysed independently by both review authors. Methodology and results were critically appraised and outcomes scanned included cognition, behavioural change, mortality and institutionalisation. Main results No trials were eligible for inclusion in this review. Authors’ conclusions The most recent search for references to relevant research was carried out in March 2012. No trials were found for inclusion in this systematic review. Low-dose aspirin is frequently used as ‘treatment as normal’ in control groups and as a baseline treatment in pharmacological trials. There is still no good evidence that
Taylor, Warren D.; Aizenstein, Howard J.; Alexopoulos, George S.
The ‘Vascular Depression’ hypothesis posits that cerebrovascular disease may predispose, precipitate, or perpetuate some geriatric depressive syndromes. This hypothesis stimulated much research that has improved our understanding of the complex relationships between late-life depression (LLD), vascular risk factors, and cognition. Succinctly, there are well-established relationships between late-life depression, vascular risk factors, and cerebral hyperintensities, the radiological hallmark of vascular depression. Cognitive dysfunction is common in late-life depression, particularly executive dysfunction, a finding predictive of poor antidepressant response. Over time, progression of hyperintensities and cognitive deficits predicts a poor course of depression and may reflect underlying worsening of vascular disease. This work laid the foundation for examining the mechanisms by which vascular disease influences brain circuits and influences the development and course of depression. We review data testing the vascular depression hypothesis with a focus on identifying potential underlying vascular mechanisms. We propose a disconnection hypothesis, wherein focal vascular damage and white matter lesion location is a crucial factor influencing neural connectivity that contributes to clinical symptomatology. We also propose inflammatory and hypoperfusion hypotheses, concepts that link underlying vascular processes with adverse effects on brain function that influence the development of depression. Testing such hypotheses will not only inform the relationship between vascular disease and depression but also provide guidance on the potential repurposing of pharmacological agents that may improve late-life depression outcomes. PMID:23439482
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.
Christenson, Brian M.; Gipson, Matthew G.; Smith, Mitchell T.
Vascular malformations (VMs) comprise a wide spectrum of lesions that are classified by content and flow characteristics. These lesions, occurring in both focal and diffuse forms, can involve any organ and tissue plane and can cause significant morbidity in both children and adults. Since treatment strategy depends on the type of malformation, correct diagnosis and classification of a vascular lesion are crucial. Slow-flow VMs (venous and lymphatic malformations) are often treated by sclerotherapy, whereas fast-flow lesions (arteriovenous malformations) are generally managed with embolization. In addition, some cases of VMs are best treated surgically. This review will present an overview of VMs in the female pelvis as well as a discussion of endovascular therapeutic techniques. PMID:24436563
Ivanov, A N; Puchinyan, D M; Norkin, I A
Endothelium is an important regulator of selective permeability of the vascular wall for different molecules and cells. This review summarizes current data on endothelial barrier function. Endothelial glycocalyx structure, its function and role in the molecular transport and leukocytes migration across the endothelial barrier are discussed. The mechanisms of transcellular transport of macromolecules and cell migration through endothelial cells are reviewed. Special section of this article addresses the structure and function of tight and adherens endothelial junction, as well as their importance for the regulation of paracellular transport across the endothelial barrier. Particular attention is paid to the signaling mechanism of endothelial barrier function regulation and the factors that influence on the vascular permeability.
Rich, Norman M
This article provides a brief historical review of treatment of vascular trauma. Although methods for ligation came into use in the second century, this knowledge was lost during the Dark Ages and did not come back until the Renaissance. Many advances in vascular surgery occurred during the Balkan Wars, World War I, and World War II, although without antibiotics and blood banking, the philosophy of life over limb still ruled. Documenting and repairing both arteries and veins became more common during the Korean and Vietnam conflicts. Increased documentation has revealed that the current conflicts have resulted in more arterial injuries than in previous wars, likely because of improved body armor, improvised explosive device attacks, tourniquet use, and improved medical evacuation time. This brief review emphasizes the great value of mentorship and the legacy of the management of arterial and venous injuries to be passed on.
Recent major improvements in a number of imaging techniques now allow for the study of the brain in ways that could not be considered previously. Researchers today have well-developed tools to specifically examine the dynamic nature of the blood vessels in the brain during development and adulthood; as well as to observe the vascular responses in disease situations in vivo. This review offers a concise summary and brief historical reference of different imaging techniques and how these tools can be applied to study the brain vasculature and the blood-brain barrier integrity in both healthy and disease states. Moreover, it offers an overview on available transgenic animal models to study vascular biology and a description of useful online brain atlases. PMID:28042833
Using a pressure gradient to drive the blood flow, and the external pressure induced by a blast wave through the surrounding brain elements, an...unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT Many numerical models for the brain do not include the vascular structures within the brain and thus...are incapable of predicting damage to the cerebral vasculature. The presence of the vasculature within the brain produces a reinforcing effect and
Nieminen, Kaisa; Blomster, Tiina; Helariutta, Ykä; Mähönen, Ari Pekka
Secondary phloem and xylem tissues are produced through the activity of vascular cambium, the cylindrical secondary meristem which arises among the primary plant tissues. Most dicotyledonous species undergo secondary development, among them Arabidopsis. Despite its small size and herbaceous nature, Arabidopsis displays prominent secondary growth in several organs, including the root, hypocotyl and shoot. Together with the vast genetic resources and molecular research methods available for it, this has made Arabidopsis a versatile and accessible model organism for studying cambial development and wood formation. In this review, we discuss and compare the development and function of the vascular cambium in the Arabidopsis root, hypocotyl, and shoot. We describe the current understanding of the molecular regulation of vascular cambium and compare it to the function of primary meristems. We conclude with a look at the future prospects of cambium research, including opportunities provided by phenotyping and modelling approaches, complemented by studies of natural variation and comparative genetic studies in perennial and woody plant species. PMID:26078728
Lammert, Eckhard; Axnick, Jennifer
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. PMID:22474612
Moss, Heather E
The retinal circulation is a potential marker of cerebral vascular disease because it shares origin and drainage with the intracranial circulation and because it can be directly visualized using ophthalmoscopy. Cross-sectional and cohort studies have demonstrated associations between chronic retinal and cerebral vascular disease, acute retinal and cerebral vascular disease, and chronic retinal vascular disease and acute cerebral vascular disease. In particular, certain qualitative features of retinopathy, retinal artery occlusion, and increased retinal vein caliber are associated with concurrent and future cerebrovascular events. These associations persist after accounting for confounding variables known to be disease-causing in both circulations, which supports the potential use of retinal vasculature findings to stratify individuals with regards to cerebral vascular disease risk.
Bowman, Marion A. Hofmann; McNally, Elizabeth M.
Vascular calcification is an independent risk factor for cardiovascular disease. Arterial calcification of the aorta, coronary, carotid and peripheral arteries becomes more prevalent with age. Genomewide association studies have identified regions of the genome linked to vascular calcification, and these same regions are linked to myocardial infarction risk. The 9p21 region linked to vascular disease and inflammation also associates with vascular calcification. In addition to these common variants, rare genetic defects can serve as primary triggers of accelerated and premature calcification. Infancy-associated calcific disorders are caused by loss of function mutations in ENPP1 an enzyme that produces extracellular pyrophosphate. Adult onset vascular calcification is linked to mutations NTE5, another enzyme that regulates extracellular phosphate metabolism. Common conditions that secondarily enhance vascular calcification include atherosclerosis, metabolic dysfunction, diabetes, and impaired renal clearance. Oxidative stress and vascular inflammation, along with biophysical properties, converge with these predisposing factors to promote soft tissue mineralization. Vascular calcification is accompanied by an osteogenic profile, and this osteogenic conversion is seen within the vascular smooth muscle itself as well as the matrix. Herein we will review the genetic causes of medial calcification in the smooth muscle layer, focusing on recent discoveries of gene mutations that regulate extracellular matrix phosphate production and the role of S100 proteins as promoters of vascular calcification. PMID:23040839
Mottarella, Scott E.; Rosa, Mario; Bangura, Abdul; Bernstein, Herbert J.; Craig, Paul A.
The aim of the Structural Biology Extensible Visualization Scripting Language (SBEVSL) project is to allow users who are experts in one scripting language to use that language in a second molecular visualization environment without requiring the user to learn a new scripting language. ConSCRIPT, the first SBEVSL release, is a plug-in for PyMOL that accepts RasMol scripting commands either as premade scripts or as line-by-line entries from PyMOL's own command line. The plug-in is available for download at http://sourceforge.net/projects/sbevsl/files in the ConSCRIPT folder. PMID:21567873
The incidence of thromboses among young women has increased with widespread use of oral contraceptives (OCs) due to the significant thromboembolic risk of estrogen. Estrogens intervene at the vascular, platelet, and plasma levels as a function of hormonal variations in the menstrual cycle, increasing the aggregability of the platelets and thrombocytes, accelerating the formation of clots, and decreasing the amount of antithrombin III. Estrogens are used in medicine to treat breast and prostate cancers and in gynecology to treat dysmenorrhea, during the menopause, and in contraception. Smoking, cardiovascular disease and hypertension, hypercholesterolemia, and diabetes are contraindicators to estrogen use. Thrombosis refers to blockage of a blood vessel by a clot or thrombus. Before estrogens are prescribed, a history of phlebitis, obesity, hyperlipidemia, or significant varicosities should be ruled out. A history of venous thrombosis, hyperlipoproteinemia, breast nodules, serious liver condition, allergies to progesterone, and some ocular diseases of vascular origin definitively rule out treatment with estrogens. A family history of infarct, embolism, diabetes, cancer, or vascular accidents at a young age signals a need for greater patient surveillance. All patients receiving estrogens should be carefully observed for signs of hypertension, hypercholesterolemia, hypercoagulability, or diabetes. Nurses have a role to play in carefully eliciting the patient's history of smoking, personal and family medical problems, and previous and current laboratory results, as well as in informing the patients of the risks and possible side effects of OCs, especially for those who smoke. Nurses should educate patients receiving estrogens, especially those with histories of circulatory problems, to avoid standing in 1 position for prolonged periods, avoid heat which is a vasodilator, avoid obesity, excercise regularly, wear appropriate footgear, and follow other good health
Etl, S; Hafer, G; Mundinger, A
The case of a 25 year old male with a stab wound of common carotid artery and the internal jugular vein is reported. He was admitted in severe hemorrhagic shock and immediately treated successfully by arterial reconstruction by means of a venous patch. Mild, declining neurological deficits correlated in magnetic resonance imaging with disturbances in the perfusion area of the medial cerebral artery. A survey of the literature shows that the fast repair of the carotid artery is clearly to be given preference to ligature. First can be executed successfully in exceptional emergency cases also by non-carotid surgeons, if basic vascular-surgical techniques are controlled.
Vascular cognitive impairment defines alterations in cognition, ranging from subtle deficits to full-blown dementia, attributable to cerebrovascular causes. Often coexisting with Alzheimer’s disease, mixed vascular and neurodegenerative dementia has emerged as the leading cause of age-related cognitive impairment. Central to the disease mechanism is the crucial role that cerebral blood vessels play in brain health, not only for the delivery of oxygen and nutrients, but also for the trophic signaling that links inextricably the well being of neurons and glia to that of cerebrovascular cells. This review will examine how vascular damage disrupts these vital homeostatic interactions, focusing on the hemispheric white matter, a region at heightened risk for vascular damage, and on the interplay between vascular factors and Alzheimer’s disease. Finally, preventative and therapeutic prospects will be examined, highlighting the importance of midlife vascular risk factor control in the prevention of late-life dementia. PMID:24267647
Stapleton, Phoebe A.; Nurkiewicz, Timothy R.
Once considered primarily occupational, novel nanotechnology innovation and application has led to widespread domestic use and intentional biomedical exposures. With these exciting advances, the breadth and depth of toxicological considerations must also be expanded. The vascular system interacts with every tissue in the body, striving to homeostasis. Engineered nanomaterials (ENM) have been reported to distribute in many different organs and tissues. However, these observations have tended to use approaches requiring tissue homogenization and/or gross organ analyses. These techniques, while effective in establishing presence, preclude an exact determination of where ENM are deposited within a tissue. It is necessary to identify this exact distribution and deposition of ENM throughout the cardiovascular system, with respect to vascular hemodynamics and in vivo/ in vitro ENM modifications taken into account if nanotechnology is to achieve its full potential. Distinct levels of the vasculature will first be described as individual compartments. Then the vasculature will be considered as a whole. These unique compartments and biophysical conditions will be discussed in terms of their propensity to favor ENM deposition. Understanding levels of the vasculature will also be discussed. Ultimately, future studies must verify the mechanisms speculated on and presented herein. PMID:24777845
Dudrick, Stanley J
Milestones in the history of the development of vascular access and the subsequent advances in practical clinical applications of the knowledge, techniques, technology, and experience to the beneficial management of a variety of patients are described. The original achievements are presented and briefly discussed primarily, but not exclusively, in relationship to the successful development of parenteral nutrition (PN). Beginning with the discovery of the circulation of blood, landmark events, resulting from astute observations, experimentation, and ingenious technological advances, are summarized or outlined chronologically over the past 4 centuries, with emphasis on the many recent accomplishments of basic and clinical scientists during the past 6 decades. Brief descriptions of several seminal contributions to safe and effective IV access, management, and therapy acknowledge and recognize the historical highlights that have allowed a complex and potentially hazardous therapeutic modality to evolve into a commonly applied useful adjunct to our current inpatient and outpatient armamentarium. A comprehensive list of references documents the highlights of the development of vascular access for the student of history.
Jost, Maud; Maillard, Catherine; Lecomte, Julie; Lambert, Vincent; Tjwa, Marc; Blaise, Pierre; Alvarez Gonzalez, Maria-Luz; Bajou, Khalid; Blacher, Silvia; Motte, Patrick; Humblet, Chantal; Defresne, Marie Paule; Thiry, Marc; Frankenne, Francis; Gothot, André; Carmeliet, Peter; Rakic, Jean-Marie; Foidart, Jean-Michel; Noël, Agnès
An adequate balance between serine proteases and their plasminogen activator inhibitor-1 (PAI-1) is critical for pathological angiogenesis. PAI-1 deficiency in mice is associated with impaired choroidal neovascularization (CNV) and tumoral angiogenesis. In the present work, we demonstrate unexpected differences in the contribution of bone marrow (BM)-derived cells in these two processes regulated by PAI-1. PAI-1−/− mice grafted with BM-derived from wild-type mice were able to support laser-induced CNV formation but not skin carcinoma vascularization. Engraftment of irradiated wild-type mice with PAI-1−/− BM prevented CNV formation, demonstrating the crucial role of PAI-1 delivered by BM-derived cells. In contrast, the transient infiltration of tumor transplants by local PAI-1-producing host cells rather than by BM cells was sufficient to rescue tumor growth and angiogenesis in PAI-1-deficient mice. These data identify PAI-1 as a molecular determinant of a local permissive soil for tumor angiogenesis. Altogether, the present study demonstrates that different cellular mechanisms contribute to PAI-1-regulated tumoral and CNV. PAI-1 contributes to BM-dependent choroidal vascularization and to BM-independent tumor growth and angiogenesis. PMID:17717143
Ellard, L; Djaiani, G
Patients presenting with vascular emergencies including acute aortic syndrome, ruptured thoracic or abdominal aortic aneurysms, thoracic aortic trauma and acute lower limb ischaemia have a high risk of peri-operative morbidity and mortality. Although anatomical suitability is not universal, endovascular surgery may improve mortality and the results of ongoing randomised controlled trials are awaited. Permissive hypotension pre-operatively should be the standard of care with the systolic blood pressure kept to 50-100 mmHg as long as consciousness is maintained. The benefit of local anaesthesia over general anaesthesia is not definitive and this decision should be tailored for a given patient and circumstance. Cerebrospinal fluid drainage for prevention of paraplegia is often impractical in the emergency setting and is not backed by strong evidence; however, it should be considered postoperatively if symptoms develop. We discuss the pertinent anaesthetic issues when a patient presents with a vascular emergency and the impact that endovascular repair has on anaesthetic management. Anaesthesia © 2012 The Association of Anaesthetists of Great Britain and Ireland.
Nolly, H; Damiani, M T; Miatello, R
The vascular wall itself, through a complex interplay of endocrine, neurocrine and autoparacrine mechanisms, plays an active role in vascular homeostasis. The endothelial cell senses humoral and hemodynamic changes and responds by secreting a variety of metabolically active substances that act locally causing either vasodilatation or vasoconstriction. Kallikrein (KK) and the mRNA for KK are present in arteries and veins. Vascular KK releases kinins from kininogen which circulate in plasma and is also present in vascular tissue. Vascular-derived kinins induce vasodilatation through the release of endothelial compounds (prostacyclin, EDRFs and cytochrome P-450). Disturbance in the delicate balance between vasodilators and vasoconstrictors may play a role in the development of hypertension. Vascular kallikrein (VKK) was significantly (P < 0.05) elevated after 2 weeks of development of renovascular and mineralocorticoid hypertension, and blood pressure was only slightly elevated. However, VKK decreased in both experimental models when blood pressure was increased. It is possible that the increase in VKK in the early stages resulted in increased local vasodilatory activity, thus counteracting the rise in blood pressure. As hypertension developed, KK was significantly decreased in arteries. The decrease in arterial KK during established hypertension is most likely secondary to high blood pressure. When the endothelium is damaged by high blood pressure, diabetes, excessive LDL cholesterol or cigarette smoking, a net imbalance favoring vasoconstriction, proliferation and migration of cells and increased lipid deposition predisposes to specific vascular diseases. Converting enzyme inhibitors (CEI) blunt the proliferative response of vascular smooth muscle cells after endothelial injury. The cardiovascular protective effects of CEI are mediated in part by the antihypertrophic, antihyperplastic and antithrombotic effects of kinins. The vascular kallikrein-kinin system has a
Scarpella, Enrico; Helariutta, Ykä
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.
Gorelick, Philip B.; Counts, Scott E.; Nyenhuis, David
Vascular contributions to cognitive impairment are receiving heightened attention as potentially modifiable factors for dementias of later life. These factors have now been linked not only to vascular cognitive disorders but also Alzheimer’s disease. In this chapter we review 3 related topics that address vascular contributions to cognitive impairment: 1. vascular pathogenesis and mechanisms; 2. neuropsychological and neuroimaging phenotypic manifestations of cerebrovascular disease; and 3. prospects for prevention of cognitive impairment of later life based on cardiovascular and stroke risk modification.1 PMID:26704177
Elomaa, Laura; Yang, Yunzhi Peter
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.
Hingorani, Anil P; Ascher, Enrico; Marks, Natalie; Shiferson, Alexander; Puggioni, Alessandra; Tran, Victor; Patel, Nirav; Jacob, Theresa
In an attempt to identify the fellows' concerns about the future of the field of vascular surgery, we conducted a survey consisting of 22 questions at an annual national meeting in March from 2004 to 2007. In order to obtain accurate data, all surveys were kept anonymous. The fellows were asked (1) what type of practice they anticipated they would be in, (2) what the new training paradigm for fellows should be, (3) to assess their expectation of the needed manpower with respect to the demand for vascular surgeons, (4) what were major threats to the future of vascular surgery, (5) whether they had heard of and were in favor of the American Board of Vascular Surgery (ABVS), (6) who should be able to obtain vascular privileges, and (7) about their interest in an association for vascular surgical trainees. Of 273 attendees, 219 (80%) completed the survey. Males made up 87% of those surveyed, and 60% were between the ages of 31 and 35 years. Second-year fellows made up 82% of those surveyed. Those expecting to join a private, academic, or mixed practice made up 35%, 28%, and 20% of the respondents, respectively, with 71% anticipating entering a 100% vascular practice. Forty percent felt that 5 years of general surgery with 2 years of vascular surgery should be the training paradigm, while 45% suggested 3 and 3 years, respectively. A majority, 79%, felt that future demand would exceed the available manpower, while 17% suggested that manpower would meet demand. The major challenges to the future of vascular surgery were felt to be competition from cardiology (82%) or radiology (30%) and lack of an independent board (29%). Seventeen percent were not aware of the ABVS, and only 2% were against it; 71% suggested that vascular privileges be restricted to board-certified vascular surgeons. Seventy-six percent were interested in forming an association for vascular trainees to address the issues of the future job market (67%), endovascular training during fellowship (56
Vascular endothelium plays a key role in blood pressure regulation. Recently, it has been shown that a 5% increase of plasma sodium concentration (sodium excess) stiffens endothelial cells by about 25%, leading to cellular dysfunction. Surface measurements demonstrated that the endothelial glycocalyx (eGC), an anionic biopolymer, deteriorates when sodium is elevated. In view of these results, a two-barrier model for sodium exiting the circulation across the endothelium is suggested. The first sodium barrier is the eGC which selectively buffers sodium ions with its negatively charged prote-oglycans.The second sodium barrier is the endothelial plasma membrane which contains sodium channels. Sodium excess, in the presence of aldosterone, leads to eGC break-down and, in parallel, to an up-regulation of plasma membrane sodium channels. The following hypothesis is postulated: Sodium excess increases vascular sodium permeability. Under such con-ditions (e.g. high-sodium diet), day-by-day ingested sodium, instead of being readily buffered by the eGC and then rapidly excreted by the kidneys, is distributed in the whole body before being finally excreted. Gradually, the sodium overload damages the organism. PMID:22471931
Blaisdell, F William
As the result of the insistence of the Surgeon General during the United States Civil War, there was extensive documentation of injuries to major blood vessels and their resulting complications. The specific treatment of vascular injuries during the Civil War was ligation of the injured vessel or amputation. This was before there was any knowledge of the cause and prevention of infection. Overall, the results were dismal, with a mortality rate of nearly 60% for the more than 1000 soldiers treated by arterial ligation. The most important contribution of these medical reports was to define how the injuries should be diagnosed and managed. Many of the principles that developed as the result of this post-war review are as valid today as they were then. Unfortunately, it seems that many of these lessons have had to be relearned by the surgeons who have participated in each of our subsequent military conflicts.
Strokes in the distribution of the posterior circulation may present with vertigo, imbalance, and nystagmus. Although the vertigo due to a posterior circulation stroke is usually associated with other neurologic symptoms or signs, small infarcts involving the cerebellum or brainstem can develop vertigo without other localizing symptoms. Approximately 11% of the patients with an isolated cerebellar infarction present with isolated vertigo, nystagmus, and postural unsteadiness mimicking acute peripheral vestibular disorders. The head impulse test can differentiate acute isolated vertigo associated with cerebellar strokes (particularly within the territory of the posterior inferior cerebellar artery) from more benign disorders involving the inner ear. Acute audiovestibular loss may herald impending infarction in the territory of anterior inferior cerebellar artery. Appropriate bedside evaluation is superior to MRIs for detecting central vascular vertigo syndromes. This article reviews the keys to diagnosis of acute isolated vertigo syndrome due to posterior circulation strokes involving the brainstem and cerebellum. PMID:25328871
Vanholder, R; Ringoir, S
Indwelling central venous catheters were consecutively used as access for acute and chronic hemodialysis, emergency treatment of pulmonary fluid overload, intoxication and electrolyte disturbances, plasmapheresis, and semiacute continuous dialysis strategies, such as continuous arteriovenous hemofiltration (CAVH). Modification in catheter structure also made it possible to use this access for long-term treatment (e.g., surgically insertable catheters [Hickman], soft large-bore catheters for blind insertion). We discuss the remaining open questions in this field: Which is the insertion site of preference (i.e., subclavian, femoral, or deep jugular)? Should we prefer stiff or soft catheters? Should soft catheters be positioned surgically or is blind insertion by nonsurgeons as adequate? Is it necessary to couple catheter insertion to adjuvant techniques, such as echographic guidance, to reduce complications? Is the currently used polymer structure of the catheters acceptable? Should catheter dialysis be used with single or double vascular access?
Fischer, M Dominik
Las mutaciones en un gran número de genes provocan degeneración de la retina y ceguera sin que exista actualmente cura alguna. En las últimas décadas, la terapia génica para enfermedades de la retina ha evolucionado y se ha convertido en un nuevo y prometedor paradigma terapéutico para estas enfermedades poco comunes. Este artículo refleja las ideas y los conceptos que parten de la ciencia básica hacia la aplicabilidad de la terapia génica en el ámbito clínico. Se describen los avances y las reflexiones actuales sobre la eficacia de los ensayos clínicos en la actualidad y se discuten los posibles obstáculos y soluciones de cara al futuro de la terapia génica para enfermedades de la retina. © 2017 S. Karger AG, Basel.
Polvani, G L; Guarino, A; Pompilio, G; Parolari, A; Piccolo, G; Sala, A; Biglioli, P
We define as Banking of the tissues all the procedures that include the finding, preparation, conservation and distribution of the homograft. The vascular homografts are taken and put into a solution of transportation at +4 degrees C and kept at this temperature till their arrival at the Bank. The following step is the dissection of the homograft which will have to be performed as quickly as possible at most 24 hours after the taking in conditions of maximum sterility. At the Italian Homograft Bank at Centro Cardiologico, the vascular homografts are kept at +4 degrees C for 96 hours on average with antibiotics. After a phase of sterilization at +4 degrees C the tissue is frozen according to a homogeneous and controlled thermic decrease and stored at -150 degrees C/-180 degrees C in fumes of liquid nitrogen till the moment of their employment allowing a long term conservation. The aim of all these procedures of cryopreservation is to keep the structural and functional integrity of cells and tissues. The thermic decrease of the tissues must occur so that to avoid all the damages of the cellular vitality and functionality and especially of the tissue structure in toto. In order to limitate these events some cryoprotector agents are employed because they reduce the concentration of the solutes, the cellular dehydration, the formation of micro-macro crystals. Another step to establish if the homograft is proper is the study of bacteriological and viral aspects. The viral screenings are performed on the donor's blood and the bacteriological tests are performed on the tissue and on the liquids. For each phase of the banking a series of information about the donor and about the tissues are recorded and filed both on paper and database so that to grant always a right conduct of the material.
In this article, the author describes the format of the Con Test, an Australian television game show which followed the same general rules and game play as the UK show PokerFace. At the end of each round a contestant needs to decide whether or not he or she should fold. A contestant needs to know how likely it is that he or she is in last place.…
Potisek, Maja; Ključevšek, Tomaž; Leskovar, Boštjan
A well-functioning vascular access is essential for successful haemodialysis in patients with end-stage kidney failure. Sometimes, when we have exploited all conventional ways of vascular access salvage, we have to find a unique solution to preserve it.
Laws, E R
Vascular complication of transsphenoidal surgery can lead to mortality and serious morbidity. In a series of 3,061 transsphenoidal operations for pituitary disease, 24 such complications were encountered, seven of which were fatal. The anatomic substrate for such complications is discussed, along with technical aspects of surgery and other methods for the avoidance of vascular complications.
Mead, A W
Vascularization of the spectacle or brille of the reptile was demonstrated by biomicroscopy, histology, fluorescein (in vivo), and Microfil silicone rubber (in situ) injections. This unusual vascularity provides new evidence for reassessment of the origin and development of this structure, and a useful tool with which to do so.
Indes, Jeffrey E; Gates, Lindsay; Mitchell, Erica L; Muhs, Bart E
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.
Isaac Newton, among others, observed that 'we see so far because we are standing upon the shoulders of giants'. In vascular surgery most of the giants have been European, and this is a heritage which we as Europeans can take pride in and build upon if we chose to do so. As in other areas of life, commitment is essential in order to influence the future. For vascular surgeons in Europe this means active participation in the European scientific societies for vascular surgery and in the UEMS. The main value of the EBSQ.VASC assessments to date has been to expose the uneven standards of training in vascular surgery within the European Union. Only if action follows to address these inequalities will the tactics of the European Board of Vascular Surgery be vindicated.
Echeverri, Darío; Montes, Félix R.; Cabrera, Mariana; Galán, Angélica; Prieto, Angélica
Caffeine is the most widely consumed stimulating substance in the world. It is found in coffee, tea, soft drinks, chocolate, and many medications. Caffeine is a xanthine with various effects and mechanisms of action in vascular tissue. In endothelial cells, it increases intracellular calcium stimulating the production of nitric oxide through the expression of the endothelial nitric oxide synthase enzyme. Nitric oxide is diffused to the vascular smooth muscle cell to produce vasodilation. In vascular smooth muscle cells its effect is predominantly a competitive inhibition of phosphodiesterase, producing an accumulation of cAMP and vasodilation. In addition, it blocks the adenosine receptors present in the vascular tissue to produce vasoconstriction. In this paper the main mechanisms of action of caffeine on the vascular tissue are described, in which it is shown that caffeine has some cardiovascular properties and effects which could be considered beneficial. PMID:21188209
Arcidiacono, T; Paloschi, V; Rainone, F; Terranegra, A; Dogliotti, E; Aloia, A; Soldati, L; Vezzoli, G
Chronic kidney disease (CKD) is characterized by phosphate retention and reduced synthesis of 1.25(OH)2-vitamin D stimulating parathyroid hyperplasia. These changes cause a complex osteopathy, defined as renal osteodystrophy, and vascular calcification. Renal osteodystrophy increases the risk of fracture and causes deformities and disability. Vascular calcification occurs in a large proportion of hemodialysis patients and is a marker of arteriopathy. Calcifying arteriopathy induces arterial stiffness and contributes to the high cardiovascular mortality and morbidity among CKD patients. Vascular calcification results from a process of local bone formation induced by osteoblast-like cells developing in the vascular wall from resident cells. Osteoblast differentiation of resident vascular cells may be mediated by metabolic factors and may be induced by high concentrations of phosphate. Therefore, phosphate retention appears as the most detrimental factor affecting arteries in CKD patients. There is no specific therapy to revert soft tissue calcification, but calcification must be prevented in the early stages of CKD.
Alvarez-Sabín, Jose; Román, Gustavo C
Cognitive decline after stroke is more common than stroke recurrence. Stroke doubles the risk of dementia and is a major contributor to vascular cognitive impairment and vascular dementia. Neuropathological studies in most cases of dementia in the elderly reveal a large load of vascular ischemic brain lesions mixed with a lesser contribution of neurodegenerative lesions of Alzheimer disease. Nonetheless, few pharmacological studies have addressed vascular cognitive impairment and vascular dementia after stroke. Citicoline has demonstrated neuroprotective effects in acute stroke and has been shown to improve cognition in patients with chronic cerebrovascular disease and in some patients with Alzheimer disease. A recent trial lasting 6 months in patients with first-ever ischemic stroke showed that citicoline prevented cognitive decline after stroke with significant improvement of temporal orientation, attention, and executive function. Experimentally, citicoline exhibits neuroprotective effects and enhances neural repair. Citicoline appears to be a safe and promising alternative to improve stroke recovery and could be indicated in patients with vascular cognitive impairment, vascular dementia, and Alzheimer disease with significant cerebrovascular disease.
Gallieni, Maurizio; Pittiruti, Mauro; Biffi, Roberto
Adequate vascular access is of paramount importance in oncology patients. It is important in the initial phase of surgical treatment or chemotherapy, as well as in the chronic management of advanced cancer and in the palliative care setting. We present an overview of the available vascular access devices and of the most relevant issues regarding insertion and management of vascular access. Particular emphasis is given to the use of ultrasound guidance as the preferred technique of insertion, which has dramatically decreased insertion-related complications. Vascular access management has considerably improved after the publication of effective guidelines for the appropriate nursing of the vascular device, which has reduced the risk of late complications, such as catheter-related bloodstream infection. However, many areas of clinical practice are still lacking an evidence-based background, such as the choice of the most appropriate vascular access device in each clinical situation, as well as prevention and treatment of thrombosis. We suggest an approach to the choice of the most appropriate vascular access device for the oncology patient, based on the literature available to date.
Vizcarra, Joaquin A.; Lang, Anthony E.; Sethi, Kapil D; Espay, Alberto J.
Progressive ambulatory impairment and abnormal white matter signal on neuroimaging come together under the diagnostic umbrella of vascular parkinsonism. A critical appraisal of the literature, however, suggests that (1) no abnormal structural imaging pattern is specific to vascular parkinsonism; (2) there is poor correlation between brain magnetic resonance imaging hyperintensities and microangiopathic brain disease and parkinsonism from available clinicopathologic data; (3) pure parkinsonism from vascular injury (“definite” vascular parkinsonism) consistently results from ischemic or hemorrhagic strokes involving the substantia nigra and/or nigrostriatal pathway but sparing the striatum itself, the cortex, and the intervening white matter; and (4) many cases reported as vascular parkinsonism may represent pseudovascular parkinsonism (e.g., Parkinson disease or another neurodegenerative parkinsonism such as progressive supranuclear palsy with non-specific neuroimaging signal abnormalities), vascular pseudoparkinsonism (e.g., akinetic mutism due to bilateral mesial frontal strokes or apathetic depression from bilateral striatal lacunar strokes), or pseudovascular pseudoparkinsonism (e.g., higher-level gait disorders, including normal pressure hydrocephalus with transependimal exudate). These syndromic designations are preferable over vascular parkinsonism until pathology or validated biomarkers confirm the underlying nature and relevance of the leukoaraiosis. PMID:25997420
Carter, Thomas; O'Neill, Stephen; Johns, Neil; Brady, Richard R W
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.
Kroeger, K; Luther, B
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.
Wani, Mohd Lateef; Ahangar, Ab Gani; Ganie, Farooq Ahmad; Wani, Shadab Nabi; Wani, Nasir-ud-din
Abstract Vascular injury presents a great challenge to the emergency resident because these injuries require urgent intervention to prevent loss of life or limb. Sometimes serious vascular injury presents with only subtle or occult signs or symptoms. The patient may present weeks or months after initial injury with symptoms of vascular insufficiency, embolization, pseudoaneurysm, arteriovenous fistula etc. Although the majority of vascular injuries are caused by penetrating trauma from gunshot wounds, stabbing or blast injury, the possibility of vascular injury needs to be considered in patients presenting with displaced long bone fractures, crush injury, prolonged immobilization in a fixed position by tight casts or bandages and various invasive procedures. iatrogenic vascular injuries constitute about 10% of cases in most series; however the incidence is an increasing trend because more endovascular procedures such as angioplasty and cardiac catheterization are being performed routinely. Civilian trauma is more frequently seen in young males. However, it can occur at any age due to road accidents, firearms, bomb blasts and diagnostic procedures. Most of the time, civilian trauma causes less tissue damage. There is an epidemic of vascular injuries in Kashmir valley because of problems in law and order in the past two decades. This review deals with the topic in detail. PMID:24350103
Konior, Anna; Schramm, Agata; Czesnikiewicz-Guzik, Marta
Abstract Significance: Reactive oxygen species (ROS) play a critical role in vascular disease. While there are many possible sources of ROS, nicotinamide adenine dinucleotide phosphate (NADPH) oxidases play a central role. They are a source of “kindling radicals,” which affect other enzymes, such as nitric oxide synthase endothelial nitric oxide synthase or xanthine oxidase. This is important, as risk factors for atherosclerosis (hypertension, diabetes, hypercholesterolemia, and smoking) regulate the expression and activity of NADPH oxidases in the vessel wall. Recent Advances: There are seven isoforms in mammals: Nox1, Nox2, Nox3, Nox4, Nox5, Duox1 and Duox2. Nox1, Nox2, Nox4, and Nox5 are expressed in endothelium, vascular smooth muscle cells, fibroblasts, or perivascular adipocytes. Other homologues have not been found or are expressed at very low levels; their roles have not been established. Nox1/Nox2 promote the development of endothelial dysfunction, hypertension, and inflammation. Nox4 may have a role in protecting the vasculature during stress; however, when its activity is increased, it may be detrimental. Calcium-dependent Nox5 has been implicated in oxidative damage in human atherosclerosis. Critical Issues: NADPH oxidase-derived ROS play a role in vascular pathology as well as in the maintenance of normal physiological vascular function. We also discuss recently elucidated mechanisms such as the role of NADPH oxidases in vascular protection, vascular inflammation, pulmonary hypertension, tumor angiogenesis, and central nervous system regulation of vascular function and hypertension. Future Directions: Understanding the role of individual oxidases and interactions between homologues in vascular disease is critical for efficient pharmacological regulation of vascular NADPH oxidases in both the laboratory and clinical practice. Antioxid. Redox Signal. 20, 2794–2814. PMID:24180474
Leopold, Jane A.
Vascular calcification is highly prevalent and, when present, is associated with major adverse cardiovascular events. Vascular smooth muscle cells play an integral role in mediating vessel calcification by undergoing differentiation to osteoblast-like cells and generating matrix vesicles that serve as a nidus for calcium-phosphate deposition in the vessel wall. Once believed to be a passive process, it is now recognized that vascular calcification is a complex and highly regulated process that involves activation of cellular signaling pathways, circulating inhibitors of calcification, genetic factors, and hormones. This review will examine several of the key mechanisms linking vascular smooth muscle cells to vessel calcification that may be targeted to reduce vessel wall mineralization and, thereby, reduce cardiovascular risk. PMID:25435520
Tascini, Guido; Passerini, Giorgio; Puliti, Paolo; Zingaretti, Primo
The analysis of morphological and structural modifications of the retina vascular network is an interesting investigation method in the study of diabetes and hypertension. Normally this analysis is carried out by qualitative evaluations, according to standardized criteria, though medical research attaches great importance to quantitative analysis of vessel color, shape and dimensions. The paper describes a system which automatically segments and recognizes the ocular fundus circulation and micro circulation network, and extracts a set of features related to morphometric aspects of vessels. For this class of images the classical segmentation methods seem weak. We propose a computer vision system in which segmentation and recognition phases are strictly connected. The system is hierarchically organized in four modules. Firstly the Image Enhancement Module (IEM) operates a set of custom image enhancements to remove blur and to prepare data for subsequent segmentation and recognition processes. Secondly the Papilla Border Analysis Module (PBAM) automatically recognizes number, position and local diameter of blood vessels departing from optical papilla. Then the Vessel Tracking Module (VTM) analyses vessels comparing the results of body and edge tracking and detects branches and crossings. Finally the Feature Extraction Module evaluates PBAM and VTM output data and extracts some numerical indexes. Used algorithms appear to be robust and have been successfully tested on various ocular fundus images.
Ghosh, Dilip; Scheepens, Arjan
Dietary patterns are widely recognised as contributors to cardiovascular and cerebrovascular disease. Endothelial function, the elastic properties of large arteries and the magnitude and timing of wave reflections are important determinants of cardiovascular performance. Several epidemiological studies suggest that the regular consumption of foods and beverages rich in flavonoids is associated with a reduction in the risk of several pathological conditions ranging from hypertension to coronary heart disease, stroke and dementia. The impairment of endothelial function is directly related to ageing and an association between decreased cerebral perfusion and dementia has been shown to exist. Cerebral blood flow (CBF) must be maintained to ensure a constant delivery of oxygen and glucose as well as the removal of waste products. Increasing blood flow is one potential way for improving brain function and the prospect for increasing CBF with dietary polyphenols is extremely promising. The major polyphenols shown to have some of these effects in humans are primarily from cocoa, wine, grape seed, berries, tea, tomatoes (polyphenolics and nonpolyphenolics), soy and pomegranate. There has been a significant paradigm shift in polyphenol research during the last decade. This review summarises our current knowledge in this area and points the way for the development of new types of functional foods targeted to brain health through improving vascular health.
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.
Ocular vascular diseases such as diabetic retinopathy, retinal vein occlusion, and age-related macular degeneration, whose population increases along with aging, have become leading causes of severe visual disturbance. Macular edema and serous retinal detachment are associated with abnormal vascular leakage and tractional retinal detachment, and neovascular glaucoma is caused by retinal neovascularization. Such ocular vascular diseases are caused by vascular cell aging and vascular damage associated with lifestyle-related diseases including diabetes mellitus, hypertension, hyperlipidemia, and obesity. In the present study, we investigated molecular mechanisms in such vascular deficiencies using vascular cell biology methodology, and we propose novel strategies for the treatment of such vascular diseases. Along with aging, oxidative stress and physical stress, such as mechanical stretch, continuously and directly insult vascular cells. Such stress induces apoptosis by intracellular signaling through stress kinases in cultured retinal vascular cells. Inhibition of such stress kinases could be an effective treatment to protect the vascular cells against age-related damage. In a retinal vascular developmental model, pericyte loss causes pathology mimicking macular edema and proliferative diabetic retinopathy. Angiopoietin 1 (Ang 1) secreted by pericytes suppresses oxidative stress-induced intracellular signaling through stress kinases linked to cell apoptosis and normalizes such retinal pathology. This suggests that the paracrine action of Ang 1 in the pericytes is necessary to sustain normal retinal vasculature, and that Ang 1-triggered intracellular signaling is useful for the treatment of vascular cell pathology associated with pericyte loss. In diabetic retinopathy and retinal vein occlusion, retinal vessels regress along with retinal vascular cell apoptosis, and the retina becomes ischemic followed by pathological retinal neovascularization. VEGF has been
Siribumrungwong, Boonying; Tomtitchong, Prakitpunthu; Kanpirom, Kitti
Preoperative vascular mapping increase rate of successful hemodialysis vascular access operation. Several studies recommend using this procedure routinely. But some studies recommend using this procedure in selected patients. So this study aims to determine the impacts of preoperative vascular mapping in unfavorable-examined patients. 55 patients were studied retrospectively from August 2006 to October 2009. Before April 2008, the operative plans were based on physical examination (group 1). After April 2008, the surgeon did preoperative vascular mapping prior to the operation in unfavorable-examined patients (group 2). The results were compared. There were high maturation rates in favorable-examined patients. In unfavorable-examined patients, preoperative vascular mapping can identified nonpalpable favorable vein which successful maturation of 18.75%. Complementary duplex scan decrease rate of unsuccessful operation significantly (p = 0.037) but does not increase maturation rate. Careful physical examination is important part before operation. Preoperative vascular mapping has benefit only in patients with unfavorable-examined patients. It finds some nonpalpable favorable vein and decrease unsuccessful exploration.
Tin, N.T.; Ty, N.D.; Hung, L.T.
The Nam Con Son basin is the largest oil and gas bearing basin in Vietnam, and has a number of producing fields. The history of studies in the basin can be divided into four periods: Pre-1975, 1976-1980, 1981-1989, and 1990-present. A number of oil companies have carried out geological and geophysical studies and conducted drilling activities in the basin. These include ONGC, Enterprise Oil, BP, Shell, Petro-Canada, IPL, Lasmo, etc. Pre-Tertiary formations comprise quartz diorites, granodiorites, and metamorphic rocks of Mesozoic age. Cenozoic rocks include those of the Cau Formation (Oligocene and older), Dua Formation (lower Miocene), Thong-Mang Cau Formation (middle Miocene), Nam Con Son Formation (upper Miocene) and Bien Dong Formation (Pliocene-Quaternary). The basement is composed of pre-Cenozoic formations. Three fault systems are evident in the basin: north-south fault system, northeast-southwest fault system, and east-west fault system. Four tectonic zones can also be distinguished: western differentiated zone, northern differentiated zone, Dua-Natuna high zone, and eastern trough zone.
Ravi, Swathi; Chaikof, Elliot L
Cardiovascular disease is the leading cause of mortality in the USA. The limited availability of healthy autologous vessels for bypass grafting procedures has led to the fabrication of prosthetic vascular conduits. While synthetic polymers have been extensively studied as substitutes in vascular engineering, they fall short of meeting the biological challenges at the blood-material interface. Various tissue engineering strategies have emerged to address these flaws and increase long-term patency of vascular grafts. Vascular cell seeding of scaffolds and the design of bioactive polymers for in situ arterial regeneration have yielded promising results. This article describes the advances made in biomaterials design to generate suitable materials that not only match the mechanical properties of native vasculature, but also promote cell growth, facilitate extracellular matrix production and inhibit thrombogenicity.
Ravi, Swathi; Chaikof, Elliot L
Cardiovascular disease is the leading cause of mortality in the USA. The limited availability of healthy autologous vessels for bypass grafting procedures has led to the fabrication of prosthetic vascular conduits. While synthetic polymers have been extensively studied as substitutes in vascular engineering, they fall short of meeting the biological challenges at the blood–material interface. Various tissue engineering strategies have emerged to address these flaws and increase long-term patency of vascular grafts. Vascular cell seeding of scaffolds and the design of bioactive polymers for in situ arterial regeneration have yielded promising results. This article describes the advances made in biomaterials design to generate suitable materials that not only match the mechanical properties of native vasculature, but also promote cell growth, facilitate extracellular matrix production and inhibit thrombogenicity. PMID:20017698
Pantelias, Konstantinos; Grapsa, Eirini
The number of patients with chronic kidney disease requiring renal replacement therapy has increased worldwide. The most common replacement therapy is hemodialysis (HD). Vascular access (VA) has a key role for successful treatment. Despite the advances that have taken place in the field of the HD procedure, few things have changed with regards to VA in recent years. Arteriovenous fistula (AVF), polytetrafluoroethylene graft and the cuffed double lumen silicone catheter are the most common used for VA. In the long term, a number of complications may present and more than one VA is needed during the HD life. The most common complications for all of VA types are thrombosis, bleeding and infection, the most common cause of morbidity in these patients. It has been estimated that VA dysfunction is responsible for 20% of all hospitalizations. The annual cost of placing and looking after dialysis VA in the United States exceeds 1 billion dollars per year. A good functional access is also vital in order to deliver adequate HD therapy. It seems that the native AVF that Brescia and Cimino described in 1966 still remains the first choice for VA. The native forearm AVFs have the longest survival and require the fewest interventions. For this reason, the forearm AVF is the first choice, followed by the upper-arm AVF, the arteriovenous graft and the cuffed central venous catheter is the final choice. In conclusion, VA remains the most important issue for patients on HD and despite the technical improvements, a number of problems and complications have to be resolved. PMID:24175244
Cachofeiro, Victoria; Miana, Maria; de Las Heras, Natalia; Martín-Fernández, Beatriz; Ballesteros, Sandra; Fernández-Tresguerres, Jesús; Lahera, Vicente
Aldosterone can act in different tissues exerting physiological and pathological effects. At the vascular level, aldosterone affects endothelial function since administration of aldosterone impaired endothelium-dependent relaxations. In addition, the administration of mineralocorticoid receptor antagonists ameliorate relaxation to acetylcholine in models of both hypertension and atherosclerosis and in patients with heart failure. A reduction in nitric oxide levels seems to be the main mechanism underlying this effect due to a reduction in its production as well as an increase in its degradation by reactive oxygen species. Aldosterone is a pro-inflammatory factor that can participate in the vascular inflammatory process associated with different pathologies including hypertension through activation of the NFkappaB system, which mediates the vascular production of different cytokines. This mineralocorticoid also participates in the vascular remodeling observed in hypertensive rats since the administration of eplerenone improved the media-to-lumen ratio in these animals. This effect seems to be due to an increase in extracellular matrix. In summary, aldosterone through mineralocorticoid receptors can participate in the vascular damage associated with different pathologies including hypertension through its prooxidant, pro-inflammatory and profibrotic effects that triggered endothelial dysfunction, an inflammatory process and vascular remodeling.
Shroff, Rukshana C; Shanahan, Catherine M
Vascular calcification is an active, cell-mediated process that results from an imbalance between the promoters and inhibitors of mineralization. The process of vascular calcification shares many similarities with that of skeletal mineralization. However, while skeletal mineralization is a regulated process induced by complex, well-timed developmental cues, vascular calcification is a pathological process, occurring in response to dysregulated/inappropriate environmental cues. Damage inducing agents present in the uremic milieu such as a mineral imbalance, induce vascular smooth muscle cell (VSMC) apoptosis, and vesicle release resulting in mineral nucleation and the deposition of hydroxyapatite. Under normal conditions, inhibitors of soft-tissue mineralization such as matrix gamma-carboxyglutamic acid protein are expressed locally within the vessel wall while others such as fetuin-A are present in the circulation. Down-regulation or perturbation of these proteins leads to a phenotypic transformation of VSMC into osteo/chondrocytic-like cells that have the capacity to modulate the mineralization process. Many aspects of the mechanisms underlying vascular calcification have been defined through in vitro studies and molecular biological techniques; however, there are still unanswered questions, particularly with respect to the relationship between bone and vascular calcification, processes that appear to be inversely related. A better understanding of the complex mechanisms regulating tissue calcification may have therapeutic potential in reducing the cardiovascular disease-associated morbidity and mortality in patients with renal disease.
Islam, J; Laing, G L; Oosthuizen, G V; Clarke, D L; Robbs, J V
The management of cervicomediastinal vascular trauma is challenging. We report on our experience with the condition in a newly established vascular trauma service unit, and compare the outcomes to those reported in our parent vascular surgery department. The details of patients with cervicomediastinal vascular injuries from January 2012 to June 2014 were retrieved for analysis from a prospective database. Ninety-three patients were identified, 84 of whom were male (90%), with an average age of 29 years. Most were penetrating injuries (89%), and 87% of these were due to stab wounds. There were 107 vascular injuries, 88 cervical and 19 mediastinal. Of these, 87 were arterial and 20 venous injuries. The most common arterial injury involved the subclavian artery (24%), followed by the common carotid artery (22%). Management was multimodal, and included conservative (8%), stenting and embolisation (8%), referral to a higher centre (8%), vascular repair (64%) and ligation (12%). Nineteen per cent required median sternotomy or thoracotomy. Eight patients died postoperatively (9%). Seven of them presented in extremis and died within 24 hours, and one died after a week from associated abdominal injuries. Postoperative complications were 9%. There was no incidence of a stroke or limb loss despite ligation of the arteries, including ligation of four internal carotids. The development of endovascular techniques would allow for noninvasive management of a significant number of patients. Open surgery is still necessary, and associated with significant morbidity. Comparable results were reported in our newly established vascular trauma service unit to those obtained in our parent vascular surgery department in Durban.
Kurz, A F
Cerebrovascular disease (CVD) and dementia frequently coexist in elderly patients. The question of whether the CVD causes the dementia depends on how 'dementia' is defined. Traditional definitions specified that dementia involved a decline in intellectual ability as a core feature. However, revised definitions have since stipulated two key elements: 1) a global rather than focal neurobehavioural deficit and 2) impairment in activities of daily living (ADL). When applied to CVD, these latter concepts of dementia raise difficulty: Focal cerebrovascular lesions in the cortex generate location-specific neurobehavioural deficits that are part of the dementia syndrome, but, even in combination, do not represent a global intellectual decline. Most cerebrovascular lesions are associated with physical symptoms that make it difficult to evaluate whether cognitive impairments have an independent impact on ADL. The majority of neurobehavioural symptoms in CVD are caused by small-vessel-type subcortical lesions and are dissimilar to those seen in Alzheimer's disease. There are several pathogenetic mechanisms, however, by which large-vessel or small-vessel CVD can cause global cognitive and intellectual impairments, allowing a diagnosis of vascular dementia (VaD): An accumulation of ischaemic lesions in the cortex may produce global intellectual impairment, particularly if they affect important areas of the brain. Single small infarcts, or haemorrhages in strategic subcortical locations, may interfere with specific circuits connecting the prefrontal cortex to the basal ganglia, or with nonspecific thalamocortical projections. This may generate combinations of executive dysfunction, personality change or apathy, which are associated with hypoperfusion and hypometabolism predominantly in frontal cortical areas. Extensive white matter lesions probably affect cognitive function through a loss of axons, producing a functional disconnection of the cortex. This can manifest as
Rohit, Manoj Kumar; Sinha, Alok Kumar; Kamana, Naveen Krishna
Background Transcatheter closure of various congenital and acquired vascular malformations with Amplatzer Vascular plugs I and II has been established. Here we present our experience with device closure. Materials and methods Between October 2006 and August 2012, nine (three males and six females) patients aged between 11 months and 62 years (mean age 19 years) underwent percutaneous device closure with AVP I and II vascular plugs for congenital and acquired arteriovenous malformation and cardiac diverticulum are presented here. Results One case of coronary cameral fistula, four cases of pulmonary arteriovenous fistula, one case of large major aortopulmonary collaterals (in tetralogy of Fallot closed before intracardiac repair), one case of congenital cardiac diverticulum, one case of fistula between external carotid artery and internal jugular vein and one case of iatrogenic carotid jugular fistula were successfully closed with AVP I and II plugs. Overall in nine cases, 16 AVP I and II plugs were deployed to occlude feeding vessels and one cardiac diverticulum. The technical success rate was 100%. No major complications were observed. Conclusion Amplatzer vascular plugs can be used successfully for closure of various congenital and acquired vascular malformations with good result. PMID:24206877
Riera-Kinkel, Carlos; Argüero-Sánchez, Rubén; Foyo-Niembro, Enrique; Castellanos, Emilio; Bravo-Ontiveros, Patricia; García-Hernández, Julio
Introducción: el objetivo de este trabajo fue identificar si la interacción de los métodos de revascularización miocárdica incrementa el área vascular funcional. Métodos: se realizó un estudio con un diseño factorial de 4x3 en 11 grupos, de cinco ratas por grupo, diez muestras por rata, evaluado a 45 días del posoperatorio, con las diferentes combinaciones quirúrgicas. La magnitud de la interacción fue evaluada tanto por inmunoexpresión del factor vascular de crecimiento derivado del endotelio, factor de crecimiento de fibroblastos y receptor de tirosina, para permitir la actividad del factor vascular de crecimiento derivado del endotelio, factor de crecimiento de fibroblastos y trombina (Flk-1), así como de la medición del área vascular; ambas medidas fueron realizadas por morfometría computarizada. Resultados: se identificó un incremento de la expresión inmunohistoquímica y del área vascular en proporción directa con la interacción; se puede afirmar (ANOVA p < 0.0001), que con la interacción de todas las maniobras se logra el efecto máximo. Conclusiones: se demuestra que la revascularización miocárdica indirecta tiene un peso especifico dentro de la revascularización miocárdica integral con un impacto real en el costo-beneficio y el costo-efectividad.
Naito, Yuji; Shinoka, Toshiharu; Duncan, Daniel; Hibino, Narutoshi; Solomon, Daniel; Cleary, Muriel; Rathore, Animesh; Fein, Corey; Church, Spencer; Breuer, Christopher
The application of tissue engineering technology to cardiovascular surgery holds great promise for improving outcomes in patients with cardiovascular diseases. Currently used synthetic vascular grafts have several limitations including thrombogenicity, increased risk of infection, and lack of growth potential. We have completed the first clinical trial evaluating the feasibility of using tissue engineered vascular grafts (TEVG) created by seeding autologous bone marrow-derived mononuclear cells (BM-MNC) onto biodegradable tubular scaffolds. Despite an excellent safety profile, data from the clinical trial suggest that the primary graft related complication of the TEVG is stenosis, affecting approximately 16% of grafts within the first seven years after implantation. Continued investigation into the cellular and molecular mechanisms underlying vascular neotissue formation will improve our basic understanding and provide insights that will enable the rationale design of second generation TEVG. Published by Elsevier B.V.
Fyodorov, Svyatoslav N.; Kopayeva, V. G.; Andreev, J. B.; Ponomarev, Gelii V.; Stranadko, Eugeny P.; Suchin, H. M.
Vascular effect of PDT has been studied in patients with corneal vascularized leucomas (10 patients) and in patients with corneal neovascularized transplant (3 patients). For vascularized leucomas the method of photodynamic therapy consisted of the local injection of dimegin (deiteroporphyrin derivative) into the space of the newly-formed vessels under operating microscope (opton) with the microneedle (diameter 200 microns) and corneal irradiation by the operating microscope light. For corneal neovascularized transplant the injection of photogem (hematoporphyrin derivative) intravenously were made with subsequent irradiation by light of dye laser (5 hours after the injection) with light density of 150 mW/cm2 for 15 minutes. In all the cases at the time of irradiation the aggregated blood flow was appeared, followed by blood flow stasis. In postoperative period the vessels disintegrated into separate fragments which disappeared completely after 10 - 15 days. Taking into account the data of light microscopy, the disappearance of the vessels took place as a result of the vascular endothelium lisis along the vascular walls. Neovascularized cornea and newly-formed vessels in tumor stroms have much in common. The vessel alterations study presented in this paper, may serve to specify the mechanism of photodynamic destruction of neovascularized stroma of tumor.
Kandasamy, Devasenathipathy; Gamanagatti, Shivanand; Gupta, Arun Kumar
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.
Fernández Alonso, L
In spite of the numerous advances made over the last two decades, the treatment of congenital vascular malformations continues to be one of the greatest enigmas facing modern medicine. There are no clear criteria concerning the indications to be followed, and even less concerning the most appropriate therapeutic procedures for each type of lesion. The results of a strictly surgical approach are discouraging and today it is accepted that congenital vascular malformations should be attended to and treated by multidisciplinary units, combining the efforts of all the specialists involved in its treatment. This paper reviews the general principles of surgical treatment of congenital vascular malformations, without losing sight of the fact that the traditional role of isolated surgery in the treatment of congenital vascular malformations has been replaced by a multidisciplinary approach to this type of lesions, making it possible to integrate embolization, sclerotherapy and surgery to improve the results. The combination of these techniques reduces the risk and complications that existed when they were applied in an isolated form. Thus, surgical treatment should not be considered as an independent tool of treatment but as a therapeutic weapon integrated in the ensemble of measures directed at improving the quality of life of the patient with a congenital vascular malformation.
Yunta, Eduardo Rodríguez
En la investigación con animales existen cuestionamientos éticos tanto en el uso como modelos de enfermedades humanas y requisito previo para ensayos en humanos como en la introducción de modificaciones genéticas. Algunos de estos cuestionamientos son: no representar exactamente la condición humana como modelos, realizar pruebas de toxicidad con grave daño para los animales, alterar su naturaleza mediante modificaciones genéticas, riesgos de la introducción de organismos genéticamente modificados. El uso de animales en investigación para beneficio humano, impone al ser humano la responsabilidad moral de respetarlo, no haciéndoles sufrir innecesariamente, al estar trabajando con seres vivientes y sentientes. PMID:23338641
Chemically induced vascular toxicity during embryonic development can result in a wide range of adverse prenatal outcomes. We used information from genetic mouse models linked to phenotypic outcomes and a vascular toxicity knowledge base to construct an embryonic vascular disrupt...
Chemically induced vascular toxicity during embryonic development can result in a wide range of adverse prenatal outcomes. We used information from genetic mouse models linked to phenotypic outcomes and a vascular toxicity knowledge base to construct an embryonic vascular disrupt...
Edwards, Malia M; Lefebvre, Olivier
The mechanisms controlling vascular development, both normal and pathological, are not yet fully understood. Many diseases, including cancer and diabetic retinopathy, involve abnormal blood vessel formation. Therefore, increasing knowledge of these mechanisms may help develop novel therapeutic targets. The identification of novel proteins or cells involved in this process would be particularly useful. The retina is an ideal model for studying vascular development because it is easy to access, particularly in rodents where this process occurs post-natally. Recent studies have suggested potential roles for laminin chains in vascular development of the retina. This review will provide an overview of these studies, demonstrating the importance of further research into the involvement of laminins in retinal blood vessel formation.
Changes in pulpal vessels in experimentally induced acute and chronic pulpitis in dog tooth were investigated using corrosive resin casts and scanning electron microscopic examination. Following a cavity preparation without water spray, increased permeability of blood vessels occurred in the primary stage of acute pulpitis. This was evidenced by the extravasation of resin from the vessel. This phenomenon was found initially in the venular network as well as in the capillary network located under the dentin. The morphological change was minimal in the vascular network underneath the cavity. This is in contrast to an expanded and tortuous vascular network representing an ulceration which was found around an abscess in chronic pulpitis. Furthermore, formation of vascular loops and AVAlc close to the inflamed region may represent a protective change in the pulp against inflammation.
Lovett, Michael; Lee, Kyongbum; Edwards, Aurelie
Tissue engineering is currently limited by the inability to adequately vascularize tissues in vitro or in vivo. Issues of nutrient perfusion and mass transport limitations, especially oxygen diffusion, restrict construct development to smaller than clinically relevant dimensions and limit the ability for in vivo integration. There is much interest in the field as researchers have undertaken a variety of approaches to vascularization, including material functionalization, scaffold design, microfabrication, bioreactor development, endothelial cell seeding, modular assembly, and in vivo systems. Efforts to model and measure oxygen diffusion and consumption within these engineered tissues have sought to quantitatively assess and improve these design strategies. This review assesses the current state of the field by outlining the prevailing approaches taken toward producing vascularized tissues and highlighting their strengths and weaknesses. PMID:19496677
Nicita-Mauro, V; Maltese, G; Nicita-Mauro, C; Basile, G
Advancing age is associated with changes in structure and function of different segments of the vascular system and is the dominant risk factor for cardiovascular diseases. The oxidative stress represents a key event of vascular aging, mainly characterized by endothelium dysfunction and reduced arterial elasticity. Age-related changes include intimal and medial thickening, arterial calcification, increased deposition of matrix substances, thus leading to a reduced compliance and increased wall stiffness, that significantly contributes to an increase in systolic blood pressure. Frail elderly patients, because of their complex clinical presentations and needs, require a special approach: the comprehensive geriatric assessment, a multidimensional process intended to determine medical, psychosocial and functional capabilities and problems in order to develop a plan for treatment and continued care. All physicians, and geriatricians in particular, must, therefore, educate their patients to healthy lifestyle to prevent or delay vascular aging, cardiovascular diseases, and to maintain a good quality of life and increase life expectancy.
Miller, L W; Wesp, A; Jennison, S H; Graham, M A; Martin, T W; McBride, L R; Pennington, D G; Peigh, P
Antibody medicated (vascular) rejection has recently been described in heart transplantation. We report our experience with vascular rejection in a series of 62 patients who did not receive perioperative lymphocyte antibody therapy. Sixty-five rejections were reported, of which 58 (89%) were pure cellular; five (8%) had both cellular and vascular components, and two (3%) had only vascular rejection. Vascular rejection was very common in patients in whom hemodynamic compromise developed, and hemodynamic compromise was significantly more common in vascular than cellular rejection. Treatment for vascular rejection included plasmapheresis, intravenous methylprednisolone, and cyclophosphamide. Only one death occurred in this series, and that occurred in a patient with vascular rejection where the diagnosis and initiation of therapy were delayed. The role of vascular rejection in patients with hemodynamic compromise is discussed.
Mavrogenis, Andreas F; Panagopoulos, George N; Kokkalis, Zinon T; Koulouvaris, Panayiotis; Megaloikonomos, Panayiotis D; Igoumenou, Vasilios; Mantas, George; Moulakakis, Konstantinos G; Sfyroeras, George S; Lazaris, Andreas; Soucacos, Panayotis N
Vascular injury in orthopedic trauma is challenging. The risk to life and limb can be high, and clinical signs initially can be subtle. Recognition and management should be a critical skill for every orthopedic surgeon. There are 5 types of vascular injury: intimal injury (flaps, disruptions, or subintimal/intramural hematomas), complete wall defects with pseudoaneurysms or hemorrhage, complete transections with hemorrhage or occlusion, arteriovenous fistulas, and spasm. Intimal defects and subintimal hematomas with possible secondary occlusion are most commonly associated with blunt trauma, whereas wall defects, complete transections, and arteriovenous fistulas usually occur with penetrating trauma. Spasm can occur after either blunt or penetrating trauma to an extremity and is more common in young patients. Clinical presentation of vascular injury may not be straightforward. Physical examination can be misleading or initially unimpressive; a normal pulse examination may be present in 5% to 15% of patients with vascular injury. Detection and treatment of vascular injuries should take place within the context of the overall resuscitation of the patient according to the established principles of the Advanced Trauma Life Support (ATLS) protocols. Advances in the field, made mostly during times of war, have made limb salvage the rule rather than the exception. Teamwork, familiarity with the often subtle signs of vascular injuries, a high index of suspicion, effective communication, appropriate use of imaging modalities, sound knowledge of relevant technique, and sequence of surgical repairs are among the essential factors that will lead to a successful outcome. This article provides a comprehensive literature review on a subject that generates significant controversy and confusion among clinicians involved in the care of trauma patients. [Orthopedics. 2016; 39(4):249-259.].
Lee, Timmy; Mokrzycki, Michele; Moist, Louise; Maya, Ivan; Vazquez, Miguel; Lok, Charmaine
Vascular access dysfunction is one of the leading causes of morbidity and mortality among end-stage renal disease patients 1,2. Vascular access dysfunction exists in all 3 types of available accesses: arteriovenous fistulas, arteriovenous grafts, and tunneled catheters. In order to improve clinical research and outcomes in hemodialysis access dysfunction, the development of a multidisciplinary network of collaborative investigators with various areas of expertise, and common standards for terminology and classification in all vascular access types is required. The North American Vascular Access Consortium (NAVAC) is a newly formed multidisciplinary and multicenter network of experts in the area of hemodialysis vascular access, who include nephrologists and interventional nephrologists from the United States and Canada with: (1) a primary clinical and research focus in hemodialysis vascular access dysfunction, (2) national and internationally recognized experts in vascular access, and (3) a history of productivity measured by peer-reviewed publications and funding among members of this consortium. The consortium’s mission is to improve the quality and efficiency in vascular access research, and impact the research in the area of hemodialysis vascular access by conducting observational studies and randomized controlled trials. The purpose of the consortium’s initial manuscript is to provide working and standard vascular access definitions relating to (1) epidemiology, (2) vascular access function, (3) vascular access patency, and (4) complications in vascular accesses relating to each of the vascular access types. PMID:21906166
Dew, Lindsey; MacNeil, Sheila; Chong, Chuh Khiun
All tissue-engineered substitutes (with the exception of cornea and cartilage) require a vascular network to provide the nutrient and oxygen supply needed for their survival in vivo. Unfortunately the process of vascular ingrowth into an engineered tissue can take weeks to occur naturally and during this time the tissues become starved of essential nutrients, leading to tissue death. This review initially gives a brief overview of the processes and factors involved in the formation of new vasculature. It then summarizes the different approaches that are being applied or developed to overcome the issue of slow neovascularization in a range of tissue-engineered substitutes. Some potential future strategies are then discussed.
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.
Enjolras, Odile; Soupre, Véronique; Picard, Arnaud
All superficial vascular abnormalities are not angiomas even though this term continues - incorrectly - to be used. Because the suffix "oma" implies a tumor, it is necessary to differentiate true vascular tumors, such as infantile hemangioma, from vascular malformations. From a hemodynamic perspective, there are two types of vascular malformations: slow- and fast-flow. In addition to the functioning of the impaired or severely damaged vessels, we discuss slow-flow capillary, venous, or lymphatic malformations and rapid flow arterial and arteriovenous malformations. All combinations are possible. There are several types of childhood vascular tumors with different courses and different prognoses. Infantile hemangioma is by far the most frequent (8 to 10 children/100). The diverse other vascular tumors in children are sufficiently rare that they are described as orphan diseases. Since the end of the last century, a simple endothelial marker, GLUT-1, is available. This immunophenotype is present in all cases of infantile hemangioma at every stage and is negative in other tumors. Kasabach-Merritt syndrome and its accompanying severe thrombocytopenia never complicate childhood hemangioma, contrary to what has been said for nearly 60 years. When it is present, the tumor is either a tufted angioma or kaposiform hemangioendothelioma, and the GLUT1 marker can distinguish them from infantile hemangioma if the histologic diagnosis is uncertain (GLUT 1 is negative in both the latter cases). There are a wide variety of rare vascular tumors; many of them are benign, isolated, or limited; some are locally aggressive and recur after excision. A small number are low-grade malignant lesions with a risk of multivessel expansion, metastasis, and sometimes a fatal outcome. Major progress has been made in the imaging of these vascular abnormalities. Magnetic resonance imaging (MRI) in particular has revolutionized the non-invasive and especially the non-irradiating exploration of many of
Converting a traditional intravenous (IV) team to a vascular resource team improves patient outcomes by empowering nurses to implement an evidence-based practice model of care. This model encourages staff nurses to learn comprehensive vascular care through education and training regarding access devices and IV therapy. Vascular resource nurses teach bedside nurses regarding best practice care for patients with complex vascular needs. This allows bedside nurses to become confident and competent in their vascular skills and knowledge. These improvements can lead to decreased catheter-related bloodstream infection rates and increased patient satisfaction scores. This article identifies best practices implemented in establishing and maintaining an effective vascular resource team.
Psaila, B; Lyden, D; Roberts, I
Dynamic interactions between hematopoietic cells and their specialized bone marrow microenvironments, namely the vascular and osteoblastic 'niches', regulate hematopoiesis. The vascular niche is conducive for thrombopoiesis and megakaryocytes may, in turn, regulate the vascular niche, especially in supporting vascular and hematopoietic regeneration following irradiation or chemotherapy. A role for platelets in tumor growth and metastasis is well established and, more recently, the vascular niche has also been implicated as an area for preferential homing and engraftment of malignant cells. This article aims to provide an overview of the dynamic interactions between cellular and molecular components of the bone marrow vascular niche and the potential role of megakaryocytes in bone marrow malignancy.
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
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.
Cloutier, Nathalie; Paré, Alexandre; Farndale, Richard W; Schumacher, H Ralph; Nigrovic, Peter A; Lacroix, Steve; Boilard, Eric
Platelets survey blood vessels, searching for endothelial damage and preventing loss of vascular integrity. However, there are circumstances where vascular permeability increases, suggesting that platelets sometimes fail to fulfill their expected function. Human inflammatory arthritis is associated with tissue edema attributed to enhanced permeability of the synovial microvasculature. Murine studies have suggested that such vascular leak facilitates entry of autoantibodies and may thereby promote joint inflammation. Whereas platelets typically help to promote microvascular integrity, we examined the role of platelets in synovial vascular permeability in murine experimental arthritis. Using an in vivo model of autoimmune arthritis, we confirmed the presence of endothelial gaps in inflamed synovium. Surprisingly, permeability in the inflamed joints was abrogated if the platelets were absent. This effect was mediated by platelet serotonin accumulated via the serotonin transporter and could be antagonized using serotonin-specific reuptake inhibitor antidepressants. As opposed to the conventional role of platelets to microvascular leakage, this demonstration that platelets are capable of amplifying and maintaining permeability adds to the rapidly growing list of unexpected functions for platelets.
Recent phylogenetic research indicates that vascular plants evolved from bryophyte-like ancestors and that this involved extensive modifications to the life cycle. These conclusions are supported by a range of systematic data, including gene sequences, as well as evidence from comparative morphology and the fossil record. Within vascular plants, there is compelling evidence for two major clades, which have been termed lycophytes (clubmosses) and euphyllophytes (seed plants, ferns, horsetails). The implications of recent phylogenetic work are discussed with reference to life cycle evolution and the interpretation of stratigraphic inconsistencies in the early fossil record of land plants. Life cycles are shown to have passed through an isomorphic phase in the early stages of vascular plant evolution. Thus, the gametophyte generation of all living vascular plants is the product of massive morphological reduction. Phylogenetic research corroborates earlier suggestions of a major representational bias in the early fossil record. Mega-fossils document a sequence of appearance of groups that is at odds with that predicted by cladogram topology. It is argued here that the pattern of appearance and diversification of plant megafossils owes more to changing geological conditions than to rapid biological diversification. PMID:10905613
Kim, D. ); Orron, D.E. )
This reference addresses the entire clinical approach to the vascular system from the diagnosis of pathology to surgery or interventional radiological management. All diagnostic imaging modalities currently available are included with specific information on how to interpret various results. It features discussions of the latest therapeutic techniques, including laser angioplasty, intravascular stents, and transluminal embolization.
Cabrera, J; Redondo, P
Traditional sclerotherapy with liquid sclerosants has been used for many years in the treatment of venous, lymphatic and low flow vascular malformations; it is efficient only with those vascular malformations of reduced size as a pre or post-operational complement. The use of liquid sclerosants has the limitations of their dilution and progressive inactivation in a great haematic volume, the irregular distribution of the sclerosant on the endothelium, the handling of the sclerosant once injected and its imperceptibility to the echo-Doppler. In their turn, both ethanol and sodium morrhuate - the most habitually employed sclerosants - produce important secondary effects. On the contrary, the use of sclerosants, specifically polidocanol in microfoam form, significantly improves the procedure, since the microfoam displaces the blood instead of mixing and diluting itself in it, thus facilitating an homogeneous distribution of the sclerosant over the endothelial surface. Finally, the echogenicity of the microbubbles, which makes them directly visible, together with their manageable consistency, means that it can be distributed more easily throughout the treated area. We comment on our experience with 50 patients with venous or low flow vascular malformations, treated with this new form of sclerosant. Similarly, the use of OK-432 (picibanil) - as the recommended sclerosant treatment in lymphatic vascular, especially macrocystic, malformations - is reviewed and its protocol given.
Jose, Matthew D; Marshall, Mark R; Read, Gail; Lioufas, Nicole; Ling, Jon; Snelling, Paul; Polkinghorne, Kevan R
Bleeding from dialysis vascular access (arteriovenous fistulas, arteriovenous grafts, and vascular catheters) is uncommon. Death from these bleeds is rare and likely to be under-reported, with incident rates of fewer than 1 episode for every 1,000 patient-years on dialysis, meaning that dialysis units may experience this catastrophic event only once a decade. There is an opportunity to learn from (and therefore prevent) these bleeding deaths. We reviewed all reported episodes of death due to vascular access bleeding in Australia and New Zealand over a 14-year period together with individual dialysis units' root cause analyses on each event. In this perspective, we provide a clinically useful summary of the evidence and knowledge gained from these rare events. Our conclusion is that death due to dialysis vascular access hemorrhage is an uncommon, catastrophic, but potentially preventable event if the right policies and procedures are put in place. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.
Kazaure, Hadiza S; Chandra, Venita; Mell, Matthew W
Existing literature on unplanned reoperation (UR) after vascular surgery is limited. The frequency of 30-day UR and its association with other adverse outcomes was analyzed. Patients who underwent vascular procedures in the American College of Surgeons National Surgical Quality Improvement Program (2012) were abstracted. UR, captured by a distinct variable now available in the data set, and its association with complications, readmissions, mortality, and failure to rescue (FTR) were analyzed using bivariate and multivariate methods. Among 35,106 patients, 3545 URs were performed on 2874 patients. The overall UR rate was 10.1%. Among patients who underwent URs, approximately 80.4%, 15.8%, and 3.8% had one, two, and three or more reoperations, respectively; 39.4% of URs occurred after initial discharge. Median time to UR was 7 days but varied by procedure. Procedures with the highest UR rates were embolectomy (18.2%), abdominal bypass (14.4%), and open procedures for peripheral vascular disease (13.8%). Common indications for UR were hemorrhage, graft failure or infection, thromboembolic events, and wound complications. Patients with URs had higher rates of subsequent complications (49.9% vs 19.9%; P < .001), readmission (41.8% vs 7.0%; P < .001), and mortality (8.0% vs 2.5%; P < .001) than those not undergoing URs. FTR was more likely among patients who had a UR (13.6% vs 9.3%; P < .001); this varied within procedure groups. After multivariate adjustment, UR was independently associated with mortality in an incremental fashion (for one UR: adjusted odds ratio, 2.0; 95% confidence interval, 1.7-2.5; for two or more URs: adjusted odds ratio, 3.1; 95% confidence interval, 2.2-4.2). URs within 30 days are frequent among patients undergoing vascular surgery and are associated with worse outcomes, including mortality and FTR. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.
Grishman, E; Venkataseshan, V S
Three groups of kidney specimens from patients with systemic lupus erythematosus (SLE) were examined for histologic evidence of vascular lesions in small arteries and arterioles. Group 1 consisted of 24 autopsy kidneys from patients who died before the advent of steroid therapy, and Group 2, of 26 more recent autopsy specimens from patients treated with steroids and/or immunosuppressive drugs. Group 3 comprised 276 renal biopsies. Group 1 showed characteristic subendothelial eosinophilic deposits in small arteries and arterioles of 8 cases; Group 2 showed similar lesions in 5 specimens, while 3 others revealed evidence of resorption of deposits. Deposits were characterized by clumping and were delimited toward the media by a thick basement membrane. Only one case showed necrotizing arteritis resembling polyarteritis nodosa. Group 3 presented vascular deposits in 19 cases and thrombotic microangiopathy in 2. Electron microscopic appearance of some of the deposits is described. Immunofluorescence microscopy showed a mixture of IgG, IgA, and IgM in 7 cases, a finding that was not seen in a group of non-lupus patients with various vascular lesions. Vascular deposits are generally rare in systemic lupus erythematosus, although in autopsies widely scattered involvement of arteries and arterioles was seen in nearly 1/3 of the cases. The deposits were more common in male patients. The evolution of the lesions could be followed through various stages to eventual sclerosis, particularly in patients treated with steroids or immunosuppressants. Some deposits appeared to resolve after treatment. Patients with vascular deposits had more severe glomerular disease and a more serious clinical course. Thrombotic microangiopathy appears to be a secondary phenomenon whose pathogenesis is unknown.
Stannard, Adam; Brohi, Karim; Tai, Nigel
Surgeons working within the United Kingdom's National Health Service have an established history of clinical innovation, research, and development in the field of vascular surgery but lack a unified trauma system to deliver optimal care for patients with vascular injury. The low incidence of vascular trauma, combined with lack of regional trauma systems, works against optimal delivery of care to the polytrauma patient. Providing care, robust data capture, and opportunities for training and education in vascular injury lag behind other elective domains of vascular practice. The challenge is to define ideal care pathways, referral networks, and standards of practice and to integrate the care of such patients. In 2010, a trauma system for London was introduced; it has provided vascular surgeons with a unique opportunity to study and advance the care of patients with vascular injury. This article discusses developing trauma network issues, particularly the organization and evolution of vascular trauma services in the United Kingdom.
Sun, Guoming; Gerecht, Sharon
Vascular diseases are a major threat to human health nowadays. While current treatments can cure some vascular diseases, their beneficial effects are only temporary; vascular regeneration holds the promise of permanent, effective treatments for many vascular diseases. Stem cells and endothelial progenitor cells can differentiate into vascular lineages and therefore have the potential to repair vascular systems. However, engineering appropriate microenvironments that will allow cell maturation and delivery remains the major challenge to the successful implementation of this treatment. This review introduces the cells that are being studied for vascular differentiation and regeneration; we then consider recent approaches to engineering microenvironments, including proper signaling cues and biodegradable scaffolds that will guide the development of these cells into vessels suitable for cell-based vascular therapy.
Zhen, Panpan; Zhao, Qian; Hou, Dandan; Liu, Teng; Jiang, Dongqiao; Duan, Jinhong; Lu, Lingqiao; Wang, Wen
Hyperhomocysteinemia (HHcy) is a well-known independent risk factor for vascular diseases in the general population. This study was to explore the effect of genistein (GST), a natural bioactive compound derived from legumes, on HHcy-induced vascular endothelial impairment in ovariectomized rats in vivo. Thirty-two adult female Wistar rats were assigned randomly into four groups (n = 8): (a) Con: control; (b) Met: 2.5% methionine diet; (c) OVX + Met: ovariectomy + 2.5% methionine diet; (d) OVX + Met + GST: ovariectomy + 2.5% methionine diet + supplementation with genistein. After 12 wk of different treatment, the rats' blood, toracic aortas and liver samples were collected for analysis. Results showed that high-methionine diet induced both elevation of plasma Hcy and endothelial dysfunction, and ovariectomy deteriorated these injuries. Significant improvement of both functional and morphological changes of vascular endothelium was observed in OVX + Met + GST group; meanwhile the plasma Hcy levels decreased remarkably. There were significant elevations of plasma ET-1 and liver MDA levels in ovariectomized HHcy rats, and supplementation with genistein could attenuate these changes. These results implied that genistein could lower the elevated Hcy levels, and prevent the development of endothelial impairment in ovariectomized HHcy rats. This finding may shed a novel light on the anti-atherogenic activities of genistein in HHcy patients.
Bruno, Rosa Maria; Ghiadoni, Lorenzo
In this issue of Diabetologia, a meta-analysis performed by Montero and co-authors (Diabetologia doi 10.1007/s00125-013-2974-1 ) demonstrates a significant impairment of vascular smooth muscle (VSM) function in type 2 diabetic patients. Endothelial function and VSM function between type 2 diabetic and healthy individuals were associated, especially in the microcirculation, confirming the hypothesis that unresponsiveness of VSM cells to NO may amplify the consequences of reduced NO availability. This study suggests a novel interpretation for endothelial dysfunction in diabetic patients, indicating VSM cells as key players. Causative mechanisms of VSM dysfunction, which seems to be a feature of the vascular phenotype of type 2 diabetes mellitus, are largely unexplored in humans. Future studies should also address the crucial issue of the prognostic significance of VSM dysfunction in diabetic patients, and possibly in other conditions characterised by high cardiovascular risk.
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vascular clamp. 870.4450 Section 870.4450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Surgical Devices § 870.4450 Vascular clamp. (a) Identification. A vascular...
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vascular clip. 870.3250 Section 870.3250 Food and... CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3250 Vascular clip. (a) Identification. A vascular clip is an implanted extravascular device designed to occlude, by compression, blood flow in...
... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Vascular clip. 870.3250 Section 870.3250 Food and... CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3250 Vascular clip. (a) Identification. A vascular clip is an implanted extravascular device designed to occlude, by compression, blood flow in...
Abou Ali, Adham N.; Salem, Karim M.; Alarcon, Louis H.; Bauza, Graciela; Pikoulis, Emmanuel; Chaer, Rabih A.; Avgerinos, Efthymios D.
Experience with temporary intravascular shunts (TIVS) for vessel injury comes from the military sector and while the indications might be clear in geographically isolated and under resourced war zones, this may be an uncommon scenario in civilian trauma. Data supporting TIVS use in civilian trauma have been extrapolated from the military literature where it demonstrated improved life and limb salvage. Few non-comparative studies from the civilian literature have also revealed similar favorable outcomes. Still, TIVS placement in civilian vascular injuries is uncommon and by some debatable given the absence of clear indications for placement, the potential for TIVS-related complications, the widespread resources for immediate and definitive vascular repair, and the need for curtailing costs and optimizing resources. This article reviews the current evidence and the role of TIVS in contemporary civilian trauma management. PMID:28775985
Iorio, F; Frantellizzi, V; Drudi, Francesco M; Maghella, F; Liberatore, M
Polysplenism and accessory spleen are congenital, usually asymptomatic anomalies. A rare case of polysplenism with ectopic spleen in pelvis of a 67-year-old, Caucasian female is reported here. A transvaginal ultrasound found a soft well-defined homogeneous and vascularized mass in the left pelvis. Patient underwent MRI evaluation and contrast-CT abdominal scan: images with parenchymal aspect, similar to spleen were obtained. Abdominal scintigraphy with 99mTc-albumin nanocolloid was performed and pelvic region was studied with planar scans and SPECT. The results showed the presence of an uptake area of the radiopharmaceutical in the pelvis, while the spleen was normally visualized. These findings confirmed the presence of an accessory spleen with an artery originated from the aorta and a vein that joined with the superior mesenteric vein. To our knowledge, in the literature, there is just only one case of a true ectopic, locally vascularized spleen in the pelvis.
Yu, Haixiang; Littlewood, Trevor; Bennett, Martin
The mammalian serine/threonine Akt kinases comprise three closely related isoforms: Akt1, Akt2 and Akt3. Akt activation has been implicated in both normal and disease processes, including in development and metabolism, as well as cancer and cardiovascular disease. Although Akt signalling has been identified as a promising therapeutic target in cancer, its role in cardiovascular disease is less clear. Importantly, accumulating evidence suggests that the three Akt isoforms exhibit distinct tissue expression profiles, localise to different subcellular compartments, and have unique modes of activation. Consistent with in vitro findings, genetic studies in mice show distinct effects of individual Akt isoforms on the pathophysiology of cardiovascular disease. This review summarises recent studies of individual Akt isoforms in atherosclerosis, vascular remodelling and aneurysm formation, to provide a comprehensive overview of Akt function in vascular disease. PMID:25929188
Smith, Frederick; Rous, Peyton
A mounting gradient of permeability exists along the capillaries of frog muscle. In chicken muscle on the other hand none has been demonstrated; but the close-knit vascularization is arranged in duplicate in such manner that the blood runs in opposite directions through the capillaries of nearly adjacent fibres. In a flight muscle of the pigeon there exists in addition to this artifice what appears to be a special collecting system of venous capillaries. In the mammalian diaphragm indications of such a system are also to be found, and a gradient of capillary permeability like that in the other skeletal muscles is probably present. These vascular conditions are briefly considered in terms of function. PMID:19869836
Trune, Dennis R.; Nguyen-Huynh, Anh
The inner ear vasculature is responsible for maintenance of the blood-labyrinth barrier, transport of systemic hormones for ion homeostasis, and supplying nutrients for metabolic functions. Unfortunately, these blood vessels also expose the ear to circulating inflammatory factors resulting from systemic diseases. Thus, while the inner ear blood vessels are critical for normal function, they also are facilitating pathologic mechanisms that result in hearing and vestibular dysfunction. In spite of these numerous critical roles of inner ear vasculature, little is known of its normal homeostatic functions and how these are compromised in disease. The objective of this review is to discuss the current concepts of vascular biology, how blood vessels naturally respond to circulating inflammatory factors, and how such mechanisms of vascular pathophysiology may cause hearing loss. PMID:25346568
Sun, Yan; Tang, Chao-Shu; DU, Jun-Bao; Jin, Hong-Fang
To review the vasorelaxant effects of hydrogen sulfide (H(2)S) in arterial rings in the cardiovascular system under both physiological and pathophysiological conditions and the possible mechanisms involved. The data in this review were obtained from Medline and Pubmed sources from 1997 to 2011 using the search terms "hydrogen sulfide" and "vascular relaxation". Articles describing the role of hydrogen sulfide in the regulation of vascular activity and its vasorelaxant effects were selected. H(2)S plays an important role in the regulation of cardiovascular tone. The vasomodulatory effects of H(2)S depend on factors including concentration, species and tissue type. The H(2)S donor, sodium hydrosulfide (NaHS), causes vasorelaxation of rat isolated aortic rings in a dose-dependent manner. This effect was more pronounced than that observed in pulmonary arterial rings. The expression of K(ATP) channel proteins and mRNA in the aortic rings was increased compared with pulmonary artery rings. H(2)S is involved in the pathogenesis of a variety of cardiovascular diseases. Downregulation of the endogenous H(2)S pathway is an important factor in the pathogenesis of cardiovascular diseases. The vasorelaxant effects of H(2)S have been shown to be mediated by activation of K(ATP) channels in vascular smooth muscle cells and via the induction of acidification due to activation of the Cl(-)/HCO(3)(-) exchanger. It is speculated that the mechanisms underlying the vasoconstrictive function of H(2)S in the aortic rings involves decreased NO production and inhibition of cAMP accumulation. H(2)S is an important endogenous gasotransmitter in the cardiovascular system and acts as a modulator of vascular tone in the homeostatic regulation of blood pressure.
Mitchell, Richard N; Libby, Peter
As therapeutic strategies to prevent acute rejection progressively improve, transplant vasculopathy (TV) constitutes the single most important limitation for long-term functioning of solid organ allografts. In TV, allograft arteries characteristically develop severe, diffuse intimal hyperplastic lesions that eventually compromise luminal flow and cause ischemic graft failure. Traditional immunosuppressive strategies that check acute allograft rejection do not prevent TV; indeed 50% of transplant recipients will have significant disease within five years of organ transplantation, and 90% will have significant TV a decade after their surgery. TV can involve the entire length of the transplanted arterial bed, including penetrating intraorgan arterioles. Indeed, the luminal narrowing of such penetrating vessels may be the most functionally significant because arterioles represent the major contributors to tissue vascular resistance. Because of the diffuseness of TV involvement in the allograft vascular bed, the only currently definitive therapy requires re-transplantation. Nevertheless, as we better understand the pathogenesis and critical mediators of these lesions, pharmacological advances can be anticipated. Other articles in this thematic review series focus on the specifics of the inciting injury, the cytokines and chemokines that drive TV development, and the nature of the recruited cells in TV lesions, as well as the pathogenic similarities between TV and other vascular lesions such as atherosclerosis. This review focuses on the mechanisms of vascular wall remodeling in TV, including the intimal accumulation of smooth muscle-like cells and associated extracellular matrix, medial smooth muscle cell degeneration, and adventitial fibrosis. A brief overview highlights the aneurysmal changes that can accrue when vessel wall inflammation has a cytokine profile distinct from the typical proinflammatory interferon-gamma-dominated milieu.
Roman, Beth L.; Pekkan, Kerem
A plethora of biochemical signals provides spatial and temporal cues that carefully orchestrate the complex process of vertebrate embryonic development. The embryonic vasculature develops not only in the context of these biochemical cues, but also in the context of the biomechanical forces imparted by blood flow. In the mature vasculature, different blood flow regimes induce distinct genetic programs, and significant progress has been made toward understanding how these forces are perceived by endothelial cells and transduced into biochemical signals. However, it cannot be assumed that paradigms that govern the mature vasculature are pertinent to the developing embryonic vasculature. The embryonic vasculature can respond to the mechanical forces of blood flow, and these responses are critical in vascular remodeling, certain aspects of sprouting angiogenesis, and maintenance of arterial-venous identity. Here, we review data regarding mechanistic aspects of endothelial cell mechanotransduction, with a focus on the response to shear stress, and elaborate upon the multifarious effects of shear stress on the embryonic vasculature. In addition, we discuss emerging predictive vascular growth models and highlight the prospect of combining signaling pathway information with computational modeling. We assert that correlation of precise measurements of hemodynamic parameters with effects on endothelial cell gene expression and cell behavior is required for fully understanding how blood flow-induced loading governs normal vascular development and shapes congenital cardiovascular abnormalities. PMID:22744845
Bissonnette, Julien; Durand, François; de Raucourt, Emmanuelle; Ceccaldi, Pierre-François; Plessier, Aurélie; Valla, Dominique; Rautou, Pierre-Emmanuel
Vascular disorders of the liver frequently affect women of childbearing age. Pregnancy and the postpartum are prothrombotic states. Pregnancy seems to be a trigger for Budd–Chiari syndrome in patients with an underlying prothrombotic disorder. Whether pregnancy is a risk factor for other vascular liver disorders is unknown. In women with a known vascular liver disorder and a desire for pregnancy, stabilisation of the liver disease, including the use of a portal decompressive procedure when indicated, should be reached prior to conception. The presence of esophageal varices should be screened and adequate prophylaxis of bleeding applied in a manner similar to what is recommended for patients with cirrhosis. Most women likely benefit from anticoagulation during pregnancy and the postpartum. Labor and delivery are best managed by a multidisciplinary team with experience in this situation. Assisted vaginal delivery is the preferred mode of delivery. Although the risk of miscarriage and premature birth is heightened, current management of these diseases makes it very likely to see the birth of a live baby when pregnancy reaches 20 weeks of gestation. PMID:25941432
Baylie, R.L.; Brayden, J.E.
Transient receptor potential channels, of the vanilloid subtype (TRPV), act as sensory mediators, being activated by endogenous ligands, heat, mechanical and osmotic stress. Within the vasculature, TRPV channels are expressed in smooth muscle cells, endothelial cells, as well as in peri-vascular nerves. Their varied distribution and polymodal activation properties make them ideally suited to a role in modulating vascular function, perceiving and responding to local environmental changes. In endothelial cells, TRPV1 is activated by endocannabinoids, TRPV3 by dietary agonists, and TRPV4 by shear stress, epoxyeicosatrienoic acids (EETs), and downstream of Gq-coupled receptor activation. Upon activation, these channels contribute to vasodilation via nitric oxide (NO), prostacyclin (PGI2), and intermediate/small conductance potassium channel (IKCa/SKCa) dependent pathways. In smooth muscle, TRPV4 is activated by endothelial derived EETs, leading to large conductance potassium channel (BKCa) activation and smooth muscle hyperpolarization. Conversely, smooth muscle TRPV2 channels contribute to global calcium entry and may aid constriction. TRPV1 and TRPV4 are expressed in sensory nerves and can cause vasodilation through CGRP and substance P release as well as mediating vascular function via the baroreceptor reflex (TRPV1) or via increasing sympathetic outflow during osmotic stress (TRPV4). Thus, TRPV channels play important roles in the regulation of normal and pathological cellular function in the vasculature. PMID:21062421
Brouillard, Pascal; Vikkula, Miikka
Vascular malformations are localized defects of vascular development. They usually affect a limited number of vessels in a restricted area of the body. Although most malformations are sporadic, inheritance is observed, enabling genetic analysis. Usually, sporadic forms present with a single lesion whereas multiple lesions are observed in familial cases. The last decade has seen unraveling of several causative genes and beginning of elucidation of the pathophysiological pathways involved in the inherited forms. In parallel, definition of the clinical phenotypes has improved and disorders such as Parkes-Weber syndrome (PKWS), first thought to be sporadic, is now known to be part of a more common inheritable phenotype. In addition, the concept of double-hit mechanism that we proposed earlier to explain the incomplete penetrance, variable expressivity and multifocality of lesions in inherited venous anomalies is now becoming confirmed, as some somatic mutations have been identified in venous, glomuvenous and cerebral cavernous malformations. It is thus tempting to suggest that familial forms of vascular malformations follow paradominant inheritance and that sporadic forms, the etiopathogenic causes of which are still unelucidated, are caused by somatic mutations in the same genes.
Endothelium is a site of metabolic activity and has a major reservoir of multipotent stem cells. It plays a vital role in the vascular physiological, pathophysiological and reparative processes. Endothelial functions are significantly altered following hypovolemic shock due to ischemia of the endothelial cells and by reperfusion due to resuscitation with fluids. Activation of endothelial cells leads to release of vasoactive substances (nitric oxide, endothelin, platelet activating factor, prostacyclin, mitochondrial N-formyl peptide), mediators of inflammation (tumor necrosis factor α, interleukins, interferons) and thrombosis. Endothelial cell apoptosis is induced following hypovolemic shock due to deprivation of oxygen required by endothelial cell mitochondria; this lack of oxygen initiates an increase in mitochondrial reactive oxygen species (ROS) and release of apoptogenic proteins. The glycocalyx structure of endothelium is compromised which causes an impairment of the protective endothelial barrier resulting in increased permeability and leakage of fluids in to the tissue causing edema. Growth factors such as angiopoetins and vascular endothelial growth factors also contribute towards pathophysiology of hypovolemic shock. Endothelium is extremely active with numerous functions, understanding these functions will provide novel targets to design therapeutic agents for the acute management of hypovolemic shock. Hypovolemic shock also occurs in conditions such as dengue shock syndrome and Ebola hemorrhagic fever, defining the role of endothelium in the pathophysiology of these conditions will provide greater insight regarding the functions of endothelial cells in vascular regulation.
Pavlović, Aleksandra; Pavlović, Dragan; Aleksić, Vuk; Sternić, Nadezda
Vascular dementia (VaD) is the second most frequent dementia after Alzheimer's disease, and is diagnosed during lifetime in 20% of demented patients. Five-year 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 forVaD are identical to stroke risk factors, and there are significant possibilities for the prevention of vascular cognitive decline. Cognitive decline develops acutely or step-by-step 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 Ila recommendation at the level of evidence A, while memantine may be useful in patients with mixed VaD and Alzheimer's disease dementia.
Farooq, Muhammad U; Min, Jiangyong; Goshgarian, Christopher; Gorelick, Philip B
Vascular cognitive impairment (VCI) is the second most common type of dementia after Alzheimer's disease (AD). Stroke and cardiovascular risk factors have been linked to both AD and VCI and potentially can affect cognitive function in mid and later life. Various pharmacological agents, including donepezil, galantamine, and memantine, approved for the treatment of AD have shown modest cognitive benefits in patients with vascular dementia (VaD). However, their functional and global benefits have been inconsistent. Donepezil has shown some cognitive benefit in patients with VaD only, and galantamine has shown some benefit in mixed dementia (AD/VaD). The benefits of other drugs such as rivastigmine, memantine, nimodipine, and piracetam are not clear. Some other supplements and herbal therapies, such as citicoline, actovegin, huperzine A, and vinpocetine, have also been studied in patients with VaD, but their beneficial effects are not well established. Non-drug therapies and lifestyle modifications such as diet, exercise, and vascular risk factor control are important in the management of VCI and should not be ignored. However, there is a need for more robust clinical trials focusing on executive function and other cognitive measures and incorporation of newer imaging modalities to provide additional evidence about the utility of these strategies in patients with VCI.
Tarbell, John M.; Simon, Scott I.; Curry, Fitz-Roy E.
Mammals are endowed with a complex set of mechanisms that sense mechanical forces imparted by blood flow to endothelial cells (ECs), smooth muscle cells, and circulating blood cells to elicit biochemical responses through a process referred to as mechanotransduction. These biochemical responses are critical for a host of other responses, including regulation of blood pressure, control of vascular permeability for maintaining adequate perfusion of tissues, and control of leukocyte recruitment during immunosurveillance and inflammation. This review focuses on the role of the endothelial surface proteoglycan/glycoprotein layer—the glycocalyx (GCX)—that lines all blood vessel walls and is an agent in mechanotransduction and the modulation of blood cell interactions with the EC surface. We first discuss the biochemical composition and ultrastructure of the GCX, highlighting recent developments that reveal gaps in our understanding of the relationship between composition and spatial organization. We then consider the roles of the GCX in mechanotransduction and in vascular permeability control and review the prominent interaction of plasma borne sphingosine-1 phosphate (S1P), which has been shown to regulate both the composition of the GCX and the endothelial junctions. Finally, we consider the association of GCX degradation with inflammation and vascular disease and end with a final section on future research directions. PMID:24905872
Fingerhut, Abe; Leppäniemi, Ari K; Androulakis, George A; Archodovassilis, F; Bouillon, Bertil; Cavina, Enrico; Chaloner, Eddie; Chiarugi, Massimo; Davidovic, Lazar; Delgado-Millan, Miguel Angel; Goris, Jan; Gunnlaugsson, Gunnar H; Jover, Jose Maria; Konstandoulakis, Manoussos M; Kurtoglu, Mehmet; Lepäntalo, Mauri; Llort-Pont, Carme; Meneu-Diaz, Juan Carlos; Moreno-Gonzales, Enrique; Navarro-Soto, Salvador; Panoussis, P; Ryan, James M; Salenius, Juha P; Seccia, Massimo; Takolander, Rabbe; Taviloglu, Korhan; Tiesenhausen, Kurt; Torfason, Bjarni; Uranüs, Selman
The rich and diverse heritage of the management of vascular injuries in the 45 independent European countries prevents the authors from revealing a uniform picture of the European experience, but some trends are clearly emerging. In countries with a low incidence of penetrating trauma and increasing use of interventional vascular procedures, the proportion of iatrogenic vascular trauma exceeds 40% of all vascular injuries, whereas on other parts of the continent, armed conflicts are still a major cause of vascular trauma. National vascular registries, mostly in the Scandinavian countries, produce useful, nationwide data about vascular trauma and its management but suffer still from inadequate data collection. Despite a relatively low incidence of vascular trauma in most European countries, the results are satisfactory, probably in most cases because of active and early management by surgeons on call, whether with vascular training or not, treating all kinds of vascular surgical emergencies. In some countries, attempts at developing a trauma and emergency surgical specialty, including expertise in the management of vascular injuries, are on their way.
The chemical diversity of estrogen and progestogen components of oral contraceptive (OC) products, their use alone or in combination, and the diversity of treatment regimens and doses account for the majority of contradictions in the immense literature on vascular and metabolic side effects of these hormones. OCs are exclusively composed of synthetic hormones. All OCs impose metabolic modifications on the organism and especially on the hepatic parenchyma due to delayed hepatic degradation. Certain factors increase the risk of vascular accidents associated with OC use: metabolic changes affecting coagulation, lipids, glucides, and arterial hypertension, immunologic phenomena, smoking, and obesity. As a whole, OCs affect coagulation by elevating factors 7 and 10, decreasing antithrombin iii (in high doses), and decreasing plasma fibrinolytic activity. synthetic estrogens cause an elevation of HDL cholesterol, a slight elevation of phospholipids, and a dose-dependent elevation of triglycerides and their VLDL fraction. As a group, progestogens tend to decrease the HDL fraction of cholesterol. Norethindrone is incapable of opposing the hypertriglyceridemic action of synthtic estrogens, while norgestrel partially opposes it. Lipid modifications provoked by combined OCs are a function of the nature and dosage of the components. Among hemodynamic modifications, synthetic estrogens cause elevations in renin substrate, plasma renin activity, angiotensin 2 and aldosterone. Synthetic progestogens may have various effects depending on type and dose, but they do not appear sufficient to cause hypertension unless other factors linked to individual predispositions are present. Microdoses of progestogens alone do not affect the renin-angiotensin-aldosterone system. Studies have also been conducted on the effect of OCs on cardiac function and on the vascular walls. Prospective studies suggest a relative risk of 3 for venous thromboembolic accidents among OC users, while
Ritt, Martin; Harazny, Joanna M; Schmidt, Stephanie; Raff, Ulrike; Ott, Christian; Michelson, Georg; Schmieder, Roland E
Haemoglobin is a potential nitric oxide (NO) scavenger. Haemoglobin is associated with blood viscosity and the red blood cell free layer width of microvessels that impact on shear stress in the microcirculation. We hypothesized that haemoglobin modulates retinal vascular function. In 139 nondiabetic male patients with haemoglobin levels within the normal range, the vasodilatatory response of retinal capillary blood flow (RCF) to flicker light exposure and the vasoconstrictor response of RCF to infusion of NO synthase inhibitor N-monomethyl-L-arginine (L-NMMA) were assessed. The latter, because of the selective nature of L-NMMA, reflects a parameter of basal NO activity of retinal vasculature. Examinations of retinal parameters were performed noninvasively and in vivo using scanning laser Doppler flowmetry. Patients with haemoglobin greater or equal the median revealed reduced increase of RCF to flicker light exposure (2.83 ± 12 vs. 9.52 ± 14 (%), P adjusted = 0.002), and greater decrease of RCF to L-NMMA infusion (-7.35 ± 13 vs. -0.92 ± 14 (%), P adjusted = 0.008), compared with patients with haemoglobin below the median. Haemoglobin was negatively related to the percentage change of RCF to flicker light exposure (r = -0.249, P = 0.004) and to L-NMMA infusion (r = -0.201, P = 0.018). In multiple linear regression analysis haemoglobin was an independent determinant of the percentage change of RCF to flicker light exposure (model 1: ß = -0.278, P = 0.003 and model 2: ß = -0.283, P = 0.002) and to L-NMMA infusion (model 1: ß = -0.256, P = 0.005 and model 2: ß = -0.269, P = 0.004). Haemoglobin emerged as an independent determinant of vascular function in the human retinal vascular bed.
Vascular anomalies, divided into vascular tumors and vascular malformations, are localized defects of angiogenesis. Hemangiomas appear soon after birth, grow quickly, and then spontaneously, but slowly, disappear. In contrast, vascular malformations are congenital defects of vascular development that grow proportionately with the child. Most vascular anomalies are considered non-hereditary. However, due to detailed analysis inherited forms have been observed, which has led to identify mutations in three genes causing familial vascular malformations: in the angiopoietin receptor TIE2 in mucocutaneous venous malformations (VMCM), in glomulin in glomuvenous malformations (GVM) and in RASA1 in the newly recognized phenotype capillary malformation-arteriovenous malformation (CM-AVM). Identification of the causative genes has permitted more precise diagnosis and differential diagnosis, evaluation of phenotypic variability among patients with a proven mutation, study of used treatments in more homogeneous patient groups, and elucidation of the etiopathogenic mechanisms behind vascular malformations. Further studies are needed to unravel the role of genetic variations in the various vascular malformations and to unravel the precise molecular mechanisms that lead to development of these vascular lesions. This should provide development of new-targeted therapies.
Haynes, Andrew; Linden, Matthew D; Chasland, Lauren C; Nosaka, Kazunori; Maiorana, Andrew J; Dawson, Ellen Adele; Dembo, Lawrence; Naylor, Louise H; Green, Daniel J
Evidence-based guidelines recommend exercise therapy for patients with chronic heart failure (CHF). Such patients have increased atherothrombotic risk. Exercise can transiently increase platelet activation and reactivity and decrease vascular function in healthy participants, although data in CHF is scant. Eccentric (ECC) cycling is a novel exercise modality which may be particularly suited to patients with CHF, but the acute impacts of ECC on platelet and vascular function are currently unknown. Our null hypothesis was that ECC and concentric (CON) cycling, performed at matched external workloads, would not induce changes in platelet or vascular function in patients with CHF. Eleven patients with heart failure with reduced ejection fraction (HFrEF) took part in discrete bouts of ECC and CON cycling. Before and immediately after exercise, vascular function was assessed by measuring diameter and flow mediated dilation (FMD) of the brachial artery. Platelet function was measured by the flow cytometric determination of glycoprotein IIb/IIIa activation and granule exocytosis in the presence and absence of platelet agonists. ECC increased baseline artery diameter (pre: 4.0±0.8mm vs post: 4.2±0.7mm, P=0.04) and decreased FMD%. When changes in baseline artery diameter were accounted for the decrease in FMD post-ECC was no longer significant. No changes were apparent after CON. Neither ECC nor CON resulted in changes to any platelet function measures (all P>0.05). These results suggest both ECC and CON cycling at a moderate intensity and short duration can be performed by patients with HFrEF, without detrimental impacts on vascular or platelet function.
Mikael, Luana de Rezende; Paiva, Anelise Machado Gomes de; Gomes, Marco Mota; Sousa, Ana Luiza Lima; Jardim, Paulo César Brandão Veiga; Vitorino, Priscila Valverde de Oliveira; Euzébio, Maicon Borges; Sousa, Wátila de Moura; Barroso, Weimar Kunz Sebba
Cardiovascular diseases (CVD) account annually for almost one third of all deaths worldwide. Among the CVD, systemic arterial hypertension (SAH) is related to more than half of those outcomes. Type 2 diabetes mellitus is an independent risk factor for SAH because it causes functional and structural damage to the arterial wall, leading to stiffness. Several studies have related oxidative stress, production of free radicals, and neuroendocrine and genetic changes to the physiopathogenesis of vascular aging. Indirect ways to analyze that aging process have been widely studied, pulse wave velocity (PWV) being considered gold standard to assess arterial stiffness, because there is large epidemiological evidence of its predictive value for cardiovascular events, and it requires little technical knowledge to be performed. A pulse wave is generated during each cardiac contraction and travels along the arterial bed until finding peripheral resistance or any bifurcation point, determining the appearance of a reflected wave. In young individuals, arteries tend to be more elastic, therefore, the reflected wave occurs later in the cardiac cycle, reaching the heart during diastole. In older individuals, however, the reflected wave occurs earlier, reaching the heart during systole. Because PWV is an important biomarker of vascular damage, highly valuable in determining the patient's global cardiovascular risk, we chose to review the articles on vascular aging in the context of cardiovascular risk factors and the tools available to the early identification of that damage. Resumo As doenças cardiovasculares são anualmente responsáveis por quase um terço do total de mortes no mundo. Dentre elas, a hipertensão arterial sistêmica (HAS) está relacionada com mais da metade desses desfechos. O diabetes mellitus tipo 2 é visto com um fator de risco independente para HAS por causar lesões funcionais e estruturais na parede arterial, ocasionando-lhe enrijecimento. Diversos estudos
Xu, Mingming; Liu, Lin; Song, Chenfang; Chen, Wei; Gui, Shuyan
This study aimed to investigate whether ghrelin ameliorated vascular calcification (VC) through improving autophagy. VC model was induced by nicotine plus vitamin D3 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.
Holding, David R; Springer, Patricia S
Vascular development is a fundamental component of leaf morphogenesis, and the mechanisms that control vascular patterning are poorly understood. We report here the identification of an enhancer trap line, Vascular Prepattern (VPP), that acts as a marker for early vascular development. GUS reporter gene expression in VPP was detected in provascular cells from the earliest stages of primary midvein formation in leaf primordia and subsequently coincided with the early specification of higher order veins. GUS expression in VPP also marks the quiescent center cells of the root apical meristem at all stages of root development. VPP provides a marker for early vascular development and will be a useful tool for studying vascular patterning.
Acosta, B; Guachalla, G; Martínez, C; Felce, S; Ledezma, G
The acute vascular compression of the duodenum is a well-recognized clinical entity, characterized by recurrent vomiting, abdominal distention, weight loss, post prandial distress. The cause of compression is considered to be effect produced as a result of the angle formed by the superior mesenteric vessels and sometimes by one of its first two branches, and vertebrae and paravertebral muscles, when the angle between superior mesenteric vessels and the aorta it's lower than 18 degrees we can saw this syndrome. The duodenojejunostomy is the best treatment, as well as in our patient.
Ikeda, Koji; Nakagawa, Yusuke; Matsubara, Hiroaki
Analysis of animal models is indispensable to elucidate the molecular mechanism in vascular calcification (VC) as well as to develop new therapies for VC. Various gene-modified mice that show VC have been reported, and considerable progress has been made through the analyses of these animals. Mice of which bone-calcification regulatory factors were modified are the representative animal models for VC, indicating that these factors certainly regulate VC as well as bone-calcification. Inducible VC in wild-type animals is also an important research tool for developing preventive and therapeutic approach for VC.
Esdaile, J.; Hawkins, D.; Gold, P.; Freedman, S. O.; Duguid, W. P.
Review of four cases of relapsing polychondritis (RP) seen at one hospital in the 12-year period 1963 to 1974 revealed that one patient had aortic insufficiency with large artery involvement, two others had involvement of medium and large arteries and the fourth may have had mucocutaneous vasculitis. Valvular disease has occurred in 9% of all cases of RP reported in the literature and, if vasculitis beyong the aortic root is included, 25% of cases of RP manifested inflammatory vascular disease. The frequency of pseudotumour of the orbit and cochlear-labyrinthine dysfunction is also high and may be a manifestation of vasculitis. PMID:870159
Ahanger, Abdul Gani; Wani, Mohd Lateef; Lone, Reyaz Ahmad; Singh, Shyam; Hussain, Zahur; Mir, Ishtiyak A; Irshad, Ifat; Ashraf, Hakeem Zubair; Dar, Abdul Majeed; Lone, Ghulam Nabi; Bhat, Mohammad Akbar; Sharma, Mukand Lal
Missile vascular injuries have reached an epidemic proportion in Kashmir valley since the eruption of militancy. The present study was undertaken to analyze the mode, pattern, presentation, and management of missile vascular injuries. A retrospective study of patients with missile vascular injury from January 1990 to October 2008 was undertaken. Five hundred eighty patients with missile vascular injury were studied. All patients with vascular injury due to causes other than missiles were excluded from the study. Most of the patients were treated by interpositional saphenous vein graft or end-to-end anastomosis. The most common complication was wound infection (22.7%) followed by graft occlusion (3.8%). The amputation rate was 3.3% and was higher in patients with a delay of >6 hours to revascularization and associated fractures. Missile vascular injury requires prompt resuscitation and revascularization. Preoperative angiography is seldom necessary. Doppler study may sometimes be needed to aid in the diagnosis.
Uryga, Anna; Gray, Kelly; Bennett, Martin
DNA damage affecting both genomic and mitochondrial DNA is present in a variety of both inherited and acquired vascular diseases. Multiple cell types show persistent DNA damage and a range of lesions. In turn, DNA damage activates a variety of DNA repair mechanisms, many of which are activated in vascular disease. Such DNA repair mechanisms either stall the cell cycle to allow repair to occur or trigger apoptosis or cell senescence to prevent propagation of damaged DNA. Recent evidence has indicated that DNA damage occurs early, is progressive, and is sufficient to impair function of cells composing the vascular wall. The consequences of persistent genomic and mitochondrial DNA damage, including inflammation, cell senescence, and apoptosis, are present in vascular disease. DNA damage can thus directly cause vascular disease, opening up new possibilities for both prevention and treatment. We review the evidence for and the causes, types, and consequences of DNA damage in vascular disease.
Endothelial cells exert an enormous influence on blood vessels throughout the circulation, but their impact is particularly pronounced in the brain. New concepts have emerged recently regarding the role of this cell type and mechanisms that contribute to endothelial dysfunction and vascular disease. Activation of the renin-angiotensin system plays a prominent role in producing these abnormalities. Both oxidative stress and local inflammation are key mechanisms that underlie vascular disease of diverse etiology. Endogenous mechanisms of vascular protection are also present, including antioxidants, anti-inflammatory molecules, and peroxisome proliferator-activated receptor-γ. Despite their clear importance, studies of mechanisms that underlie cerebrovascular disease continue to lag behind studies of vascular biology in general. Identification of endogenous molecules and pathways that protect the vasculature may result in targeted approaches to prevent or slow the progression of vascular disease that causes stroke and contributes to the vascular component of dementia and Alzheimer's disease. PMID:21335467
Hélénon, O; Correas, J M; Eiss, D; Khairoune, A; Merran, S
Peripheral vascular disorders of the kidney involve the intrarenal branches of the renal vascular tree. It include occlusive (infarction and cortical necrosis) and non-occlusive vascular lesions (acquired arteriovenous fistulas, arteriovenous malformation, false aneurysms and microaneurysms). Initial diagnosis relies on color Doppler US and CT angiography. Angiography plays a therapeutic role. MR imaging provides useful diagnostic information on perfusion disorders especially in patients with renal insufficiency.
Mercer, Ronald W; Schwartz, Matthew C; Stephany, Joshua; Donnelly, Lane F; Franciosi, James P; Epelman, Monica
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.
Stieghorst, Michael F.; Crummy, Andrew B.; Lieberman, Robert P.; Turnipseed, William D.; Detmer, Donald E.; Berkoff, Herbert A.
Digital subtraction angiography (DSA) has considerable utility in the evaluation of peripheral vascular disease. It is useful in screening selected patients for vascular disease and its relative ease of performance and good patient tolerance make it ideal for serial examinations of post operative patients. When used in conjunction with intra arterial injections, the technique may show "run-off" vessels which were not demonstrated by standard angiography. This paper presents our experience using DSA to image peripheral vascular problems.
Yeates, A.; Enzmann, D.
Six patients with angiographically cryptic vascular malformations involving the brainstem were examined with computed tomography (CT). The clinical and CT findings of cryptic vascular malformations of the brainstem are described and distinguished from those of brainstem glioma and multiple sclerosis. Calcification within a brainstem lesion that displays relatively little mass effect and shows little contrast enhancement, particularly when associated with a long history of waxing and waning brainstem symptoms, should suggest a vascular malformation.
Okkels, Fridolin; Jacobsen, Jens Christian Brings
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 we present a simple two-dimensional model in which, as an alternative approach, the tissue is modeled as a porous medium with intervening sharply defined flow channels. Based on simple, physiologically realistic assumptions, flow-channel structure adapts so as to reach a configuration in which all parts of the tissue are supplied. A set of model parameters uniquely determine the model dynamics, and we have identified the region of the best-performing model parameters (a global optimum). This region is surrounded in parameter space by less optimal model parameter values, and this separation is characterized by steep gradients in the related fitness landscape. Hence it appears that the optimal set of parameters tends to localize close to critical transition zones. Consequently, while the optimal solution is stable for modest parameter perturbations, larger perturbations may cause a profound and permanent shift in systems characteristics. We suggest that the system is driven toward a critical state as a consequence of the ongoing parameter optimization, mimicking an evolutionary pressure on the system. PMID:23060814
Rockwell, Fulton E; Holbrook, N Michele; Stroock, Abraham D
Current models of leaf hydration employ an Ohm's law analogy of the leaf as an ideal capacitor, neglecting the resistance to flow between cells, or treat the leaf as a plane sheet with a source of water at fixed potential filling the mid-plane, neglecting the discrete placement of veins as well as their resistance. We develop a model of leaf hydration that considers the average conductance of the vascular network to a representative areole (region bounded by the vascular network), and represent the volume of tissue within the areole as a poroelastic composite of cells and air spaces. Solutions to the 3D flow problem are found by numerical simulation, and these results are then compared to 1D models with exact solutions for a range of leaf geometries, based on a survey of temperate woody plants. We then show that the hydration times given by these solutions are well approximated by a sum of the ideal capacitor and plane sheet times, representing the time for transport through the vasculature and tissue respectively. We then develop scaling factors relating this approximate solution to the 3D model, and examine the dependence of these scaling factors on leaf geometry. Finally, we apply a similar strategy to reduce the dimensions of the steady state problem, in the context of peristomatal transpiration, and consider the relation of transpirational gradients to equilibrium leaf water potential measurements. © 2013 Published by Elsevier Ltd. All rights reserved.
Voelkel, Norbert; Taraseviciene-Stewart, Laima
We propose that an endogenous maintenance program controls lung cell turnover, apoptosis, and tissue repair, and that emphysema is a manifestation of the breakdown of the lung structure maintenance program. Emphysema can be induced experimentally in rats by three methods: blockade of vascular endothelial growth factor receptors using SU5416, a small molecule-tyrosine kinase inhibitor; methylprednisolone, which activates matrix metalloproteinase-9 and decreases Akt phosphorylation; and antibodies directed against endothelial cells (autoimmune emphysema). SU5416-induced emphysema is associated with lung induction of cytochrome P450 and oxidant stress, and a superoxide dismutase mimetic or N-acetylcysteine prevents this form of emphysema. A broad-spectrum metalloproteinase inhibitor prevents methylprednisolone-induced emphysema and, finally, autoimmune emphysema is associated with increased lung tissue metalloproteinase-9 expression and alveolar septal cell apoptosis. Athymic rats, which lack CD4+ T cells, are protected against autoimmune emphysema, whereas adoptive transfer of CD4+ T cells causes autoimmune emphysema in naive adult rats. It appears that vascular endothelial growth factor and signaling via its receptors plays a central role in the lung structural maintenance program, and oxidative stress, proteolysis, and apoptosis may coincide in the moment of lung cell destruction. Interestingly, the methylprednisolone model illustrates that inflammation is not necessary for the development of emphysema.
Shimoda, Larissa A; Laurie, Steven S.
Pulmonary hypertension is a complex, progressive condition arising from a variety of genetic and pathogenic causes. Patients present with a spectrum of histologic and pathophysiological features, likely reflecting the diversity in underlying pathogenesis. It is widely recognized that structural alterations in the vascular wall contribute to all forms of pulmonary hypertension. Features characteristic of the remodeled vasculature in patients with pulmonary hypertension include increased stiffening of the elastic proximal pulmonary arteries, thickening of the intimal and/or medial layer of muscular arteries, development of vaso-occlusive lesions and the appearance of cells expressing smooth muscle specific markers in normally non-muscular small diameter vessels, resulting from proliferation and migration of pulmonary arterial smooth muscle cells and cellular trans-differentiation. The development of several animal models of pulmonary hypertension has provided the means to explore the mechanistic underpinnings of pulmonary vascular remodeling, although none of the experimental models currently used entirely replicates the pulmonary arterial hypertension observed in patients. Herein, we provide an overview of the histological abnormalities observed in humans with pulmonary hypertension and in preclinical models and discuss insights gained regarding several key signaling pathways contributing to the remodeling process. In particular, we will focus on the roles of ion homeostasis, endothelin-1, serotonin, bone morphogenetic proteins, Rho kinase and hypoxia-inducible factor 1 in pulmonary arterial smooth muscle and endothelial cells, highlighting areas of cross-talk between these pathways and potentials for therapeutic targeting. PMID:23334338
Farb, Melissa G.; Gokce, Noyan
Obesity has emerged as one of the most critical health care problems globally that is associated with the development of insulin resistance, type 2 diabetes mellitus, metabolic dysfunction and cardiovascular disease. Central adiposity with intra-abdominal deposition of visceral fat, in particular, has been closely linked to cardiometabolic consequences of obesity. Increasing epidemiological, clinical and experimental data suggest that both adipose tissue quantity and perturbations in its quality termed “adiposopathy” contribute to mechanisms of cardiometabolic disease. The current review discusses regional differences in adipose tissue characteristics and highlights profound abnormalities in vascular endothelial function and angiogenesis that are manifest within the visceral adipose tissue milieu of obese individuals. Clinical data demonstrate up-regulation of pro-inflammatory and pro-atherosclerotic mediators in dysfunctional adipose tissue that may support pathological vascular changes not only locally in fat but also in multiple organ systems, including coronary and peripheral circulations, potentially contributing to mechanisms of obesity-related cardiovascular disease. PMID:25781557
Page, C.; Rose, M.; Yacoub, M.; Pigott, R.
The antigenic status of vascular endothelium from different sites of the normal adult and fetal human cardiovascular system was investigated. Tissues included aorta (n = 9), pulmonary artery (n = 8), coronary artery (n = 6), ventricle/atrium (n = greater than 10), lymph node (n = 2), fetal whole heart (n = 3), and umbilical cord (n = 7). Frozen sections were studied using monoclonal antibodies recognizing endothelial markers (EN4, vWf, Pal-E, and 44G4), vascular adhesion molecules (ICAM-1, ELAM, VCAM, and PECAM), the monocyte/endothelial marker (OKM5), and major histocompatibility complex (MHC) molecules (class I and class II). Results demonstrate that capillary endothelium is phenotypically different from endothelial cells (EC) lining large vessels. Capillary EC strongly express MHC classes I and II, ICAM, and OKM5, which are variably weak to undetectable on large vessels. In contrast, the large vessels strongly express vWf and appear to constitutively express ELAM-1. This suggests that the capillary EC may be more efficient at antigen presentation or more susceptible to immune attack in vivo. Interestingly, normal coronary arteries, unlike all other large vessels, express MHC class II and VCAM molecules. Future studies should concentrate on comparative functional studies between capillary, coronary, and large vessel EC. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 PMID:1519671
Reekers, Jim A.; Mueller-Huelsbeck, Stefan; Libicher, Martin; Atar, Eli; Trentmann, Jens; Goffette, Pierre; Borggrefe, Jan; Zelenak, Kamil; Hooijboer, Pieter; Belli, Anna-Maria
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 <0.5% of patients. Postdeployment bleeding occurred in 6.4%, and most these (51.5%) could be managed with light manual compression. During follow-up, other device-related complications were reported in 1.3%: seven false aneurysms, three hematoma >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.
Osako, Mariana Kiomy; Nakagami, Hironori; Koibuchi, Nobutaka; Shimizu, Hideo; Nakagami, Futoshi; Koriyama, Hiroshi; Shimamura, Munehisa; Miyake, Takashi; Rakugi, Hiromi; Morishita, Ryuichi
Arterial calcification and osteoporosis are associated in postmenopausal women. RANK (the receptor activator of nuclear factor kappaB), RANKL (RANK ligand), and osteoprotegerin are key proteins in bone metabolism and have been found at the site of aortic calcification. The role of these proteins in vasculature, as well as the contribution of estrogen to vascular calcification, is poorly understood. To clarify the mechanism of RANKL system to vascular calcification in the context of estrogen deficiency. RANKL induced the calcification inducer bone morphogenetic protein-2 by human aortic endothelial cells (HAECs) and decreased the calcification inhibitor matrix Gla protein (MGP) in human aortic smooth muscle cells (HASMCs), as quantified by real-time PCR and Western blot analysis. RANKL also induced bone-related gene mRNA expression and calcium deposition (Alizarin red staining) followed by the osteogenic differentiation of HASMCs. Estrogen inhibited RANKL signaling in HAECs and HASMCs mainly through estrogen receptor alpha. Apolipoprotein E-deficient mice fed with Western high-fat diet for 3 months presented atherosclerotic calcification (Oil red and Alizarin red staining) and osteoporosis (microcomputed tomographic analysis) after ovariectomy and increased expression of RANKL, RANK, and osteopontin in atherosclerotic lesion, as detected by in situ hybridization. Estrogen replacement inhibited osteoporosis and the bone morphogenetic protein osteogenic pathway in aorta by decreasing phosphorylation of smad-1/5/8 and increasing MGP mRNA expression. RANKL contributes to vascular calcification by regulating bone morphogenetic protein-2 and MGP expression, as well as bone-related proteins, and is counteracted by estrogen in a receptor-dependent manner.
Georgakarakos, Efstratios; Bitza, Christina; Papanas, Nikolaos; Matsagkas, Miltiadis; Lazarides, Miltos K
Although peripheral arterial disease is prevalent in the primary care setting, insufficient vascular education among nurses and physicians coupled with certain economic constraints undermines treatment efficacy. Moreover, the burden of advanced venous pathology such as posthrombotic syndrome, venous ulcers, and lymphedema remains suboptimally treated. This article advocates the development of a vascular nursing specialty as a means to improving vascular care especially nowadays, when health care providers dictate comprehensive and cost-effective nursing practice and patient management. It also presents the first attempt to organize a Vascular Nursing Educational Session in Greece.
Vargas, Maria Isabel; Barnaure, Isabelle; Gariani, Joanna; Boto, José; Pellaton, Alain; Dietemann, Jean-Louis; Kulcsar, Zsolt
The various imaging techniques used to depict vascular lesions of the spinal cord are described in this article with particular emphasis on magnetic resonance imaging (MRI), vascular sequences, and advantages of high-field MRI. Technical vascular protocols are discussed in computed tomography, MRI, and conventional angiography. The diverse magnetic resonance angiography protocols are presented as well as their findings, specificities, and pitfalls. A review of the vascular anatomy and the most common pathologies analyzed by magnetic resonance angiography and conventional angiography is described.
Yue, Yong; Yao, Yong-jie; Sun, Xi-qing; Wu, Xing-yu
Weightlessness is inavoidable during spaceflight. It brings profound physiological effects on human body. Vascular remodeling is one of the important changes of cardiovascular system caused by weightlessness or simulated weightlessness. The paper summarized the studies on the effects of weightlessness or weightlessness simulation on vascular remodeling in recent years. The emergence and development of the concept of vascular remodeling were briefly reviewed. The advances of study on vascular remodeling in recent years was briefly discussed with the points focused on the effects of weightlessness or weightlessness simulation on cardiovascular remodeling and its mechanism. It is proposed that cardiovascular remodeling might be important in studying the causes of orthostatic intolerance after spaceflight.
PULMONARY HYPERTENSION , *PULMONARY BLOOD CIRCULATION, BLOOD CIRCULATION, LUNG, PATHOLOGY, VASCULAR DISEASES, ARTERIES, OBSTRUCTION(PHYSIOLOGY...EMBOLISM, HISTOLOGY, DOGS, LABORATORY ANIMALS, BLOOD PRESSURE , EXPERIMENTAL DATA, PHYSIOLOGY.
Knight, Darryl; Gillies, Elizabeth; Mequanint, Kibret
With the growing need for coronary revascularizations globally, several strategies to restore blood flow to the heart have been explored. Bypassing the atherosclerotic coronary arteries with autologous grafts, synthetic prostheses and tissue-engineered vascular grafts continue to be evaluated in search of a readily available vascular graft with clinically acceptable outcomes. The development of such a vascular graft including tissue engineering approaches both in situ and in vitro is herein reviewed, facilitating a detailed comparison on the role of seeded cells in vascular graft patency.
Manuel-Rimbau, E; Lozano, P; Gómez, A; Bethencourt, A; Gómez, F T
The increase in vascular complications after cardiac catheterizations is rising due to the increase in the total number of these procedures. The purpose of this report is to determine the incidence of this complication and to identify the variables which are related to the presence of vascular complications which required surgical repair. Retrospective review of the 3,723 cardiac catheterizations made by the interventional cardiology department during a period between June 1992 to August 1996. Thirty two vascular complications were detected (0.9%), which required surgical reparation. There was no statistical difference in age, sex, presence of vascular risk factors, cardiac indication for catheterization and vascular approach between those patients who had a vascular complication and those who did not. The presence of obesity [RR: 2.5, IC 95% (1.2-5)], use of catheter sheath, superior or equal to 8F [RR: 0.3, IC 95% (0.14-0.62)] and use of systemic anticoagulation [RR: 4.8, IC 95% (2.1-10.8)], increase the risk of vascular complications. Two patients died (6.2%) due to cardiac complications and there were minor complications in 23% after surgical repair. Vascular complications after cardiac catheterization continue to be a significant problem. There are several variables which influence the presentation of vascular complications. Continued surveillance of cardiac catheterization complications is necessary to minimize problems and improve results.
Thottappillil, Neelima; Nair, Prabha D
An ideal vascular substitute, especially in <6 mm diameter applications, is a major clinical essentiality in blood vessel replacement surgery. Blood vessels are structurally complex and functionally dynamic tissue, with minimal regeneration potential. These have composite extracellular matrix (ECM) and arrangement. The interplay between ECM components and tissue specific cells gives blood vessels their specialized functional attributes. The core of vascular tissue engineering and regeneration relies on the challenges in creating vascular conduits that match native vessels and adequately regenerate in vivo. Out of numerous vascular regeneration concerns, the relevance of ECM emphasizes much attention toward appropriate choice of scaffold material and further scaffold development strategies. The review is intended to be focused on the various approaches of scaffold materials currently in use in vascular regeneration and current state of the art. Scaffold of choice in vascular tissue engineering ranges from natural to synthetic, decellularized, and even scaffold free approach. The applicability of tubular scaffold for in vivo vascular regeneration is under active investigation. A patent conduit with an ample endothelial luminal layer that can regenerate in vivo remains an unanswered query in the field of small diameter vascular tissue engineering. Besides, scaffolds developed for vascular regeneration, should aim at providing functional substitutes for use in a regenerative approach from the laboratory bench to patient bedside. PMID:25632236
Harris, Kenneth A.; Provan, John L.
Objective To outline the distribution of vascular surgeons in Canada and to determine the present and future human resource needs in vascular surgery practice in Canada. Design Voluntary questionnaires sent to all members of the Canadian Society for Vascular Surgery (CSVS), the administrators of hospitals in Canada with more than 100 beds, and interrogation of the membership database of the CSVS. Main outcome measures The perceived present and future needs for fulltime and part-time vascular surgeons, determined by a variety of methods. Participants One hundred and forty active members of the CSVS and administrators of 120 hospitals. Main results From the CSVS members 62 responses were received from those residing in Canada, revealing 47 fulltime vascular (more than 75% of the practice) surgeons working with 0 to 5 colleagues (mean 1.8 [SD 1.3]). Fifteen responding surgeons combined the practice of vascular surgery with another specialty. Perceived immediate needs were 24 surgeons, with 42 required in 4.8 (1.8) years. Of 120 hospitals offering vascular surgery services, 90 stated that they met the needs of their community; however, additional immediate manpower requirements totalled 27 surgeons. Hospital administrators predicted a need of 55 additional vascular surgeons in a mean of 5.5 (4.6) years. Over 85% of hospitals stated that they had the resources to support the currently practising surgeons and their immediately required additions. Conclusions Prediction of the need for additional vascular surgeons should be based on an estimated retirement age of 65 years, with an adjustment for the increasing percentage of the Canadian population reaching the age of 60 years. All methodologies used in this study predict the need for additional human resources in vascular surgery. The need for continued training of new vascular surgeons is apparent, but the optimal number of trainees per year is less clear. PMID:9492746
Assar, Mariam El; Angulo, Javier
Abstract Diabetes and the ageing process independently increase the risk for cardiovascular disease (CVD). Since incidence of diabetes increases as people get older, the diabetic older adults represent the largest population of diabetic subjects. This group of patients would potentially be threatened by the development of CVD related to both ageing and diabetes. The relationship between CVD, ageing and diabetes is explained by the negative impact of these conditions on vascular function. Functional and clinical evidence supports the role of vascular inflammation induced by the ageing process and by diabetes in vascular impairment and CVD. Inflammatory mechanisms in both aged and diabetic vasculature include pro‐inflammatory cytokines, vascular hyperactivation of nuclear factor‐кB, increased expression of cyclooxygenase and inducible nitric oxide synthase, imbalanced expression of pro/anti‐inflammatory microRNAs, and dysfunctional stress‐response systems (sirtuins, Nrf2). In contrast, there are scarce data regarding the interaction of these mechanisms when ageing and diabetes co‐exist and its impact on vascular function. Older diabetic animals and humans display higher vascular impairment and CVD risk than those either aged or diabetic, suggesting that chronic low‐grade inflammation in ageing creates a vascular environment favouring the mechanisms of vascular damage driven by diabetes. Further research is needed to determine the specific inflammatory mechanisms responsible for exacerbated vascular impairment in older diabetic subjects in order to design effective therapeutic interventions to minimize the impact of vascular inflammation. This would help to prevent or delay CVD and the specific clinical manifestations (cognitive decline, frailty and disability) promoted by diabetes‐induced vascular impairment in the elderly. PMID:26435167
Assar, Mariam El; Angulo, Javier; Rodríguez-Mañas, Leocadio
Diabetes and the ageing process independently increase the risk for cardiovascular disease (CVD). Since incidence of diabetes increases as people get older, the diabetic older adults represent the largest population of diabetic subjects. This group of patients would potentially be threatened by the development of CVD related to both ageing and diabetes. The relationship between CVD, ageing and diabetes is explained by the negative impact of these conditions on vascular function. Functional and clinical evidence supports the role of vascular inflammation induced by the ageing process and by diabetes in vascular impairment and CVD. Inflammatory mechanisms in both aged and diabetic vasculature include pro-inflammatory cytokines, vascular hyperactivation of nuclear factor-кB, increased expression of cyclooxygenase and inducible nitric oxide synthase, imbalanced expression of pro/anti-inflammatory microRNAs, and dysfunctional stress-response systems (sirtuins, Nrf2). In contrast, there are scarce data regarding the interaction of these mechanisms when ageing and diabetes co-exist and its impact on vascular function. Older diabetic animals and humans display higher vascular impairment and CVD risk than those either aged or diabetic, suggesting that chronic low-grade inflammation in ageing creates a vascular environment favouring the mechanisms of vascular damage driven by diabetes. Further research is needed to determine the specific inflammatory mechanisms responsible for exacerbated vascular impairment in older diabetic subjects in order to design effective therapeutic interventions to minimize the impact of vascular inflammation. This would help to prevent or delay CVD and the specific clinical manifestations (cognitive decline, frailty and disability) promoted by diabetes-induced vascular impairment in the elderly. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.
The history of the Red List of Japanese vascular plants is briefly reviewed for editing and research. Especially on the results of recent monitoring, the present status of information and conservation activities on the endangered plants in Japan is discussed and the dynamics of the Japanese flora are taken up, in relation to basic research on plant biodiversity on the Japanese Archipelago. The figures of endangered plants are not very variable during the past quarter of a century, but we can surmise that the conservation of threatened species in Japan has been promoted to some extent. Based on the results of such a study, proposals are made to contribute to the sustainable use of plant biodiversity on the Japanese Archipelago under a global conspectus. PMID:18941303
Finielz, P; Chuet, C; Gendoo, Z; Guiserix, J
The high proportion of diabetic patients is partly responsible for the high frequency of chronic renal failure in Reunion. The confection and maintenance of an arterio-venous fistule is a major problem in those patients. We report herein our experience with temporary vascular access by internal jugular vein catherization with subcutaneous tunnelization using silastic catheters. The mean duration of utilisation of these accesses is 107 days for diabetic patients and 98 days for nondiabetic patients. The major complication observed is sepsis (18.36%). Diabetes mellitus which represent a traditional risk factor does not seem to be responsible here, the climatic and hygienic conditions prevailing in this part of the world could be a contributing factor. Nevertheless, we find the utilisation of these catheters a suitable solution during the waiting period because it is an easy operation, of the good quality of the material used and the comfort brought to the patient.
Vascular radiology of the liver has increased in scope and function in recent years due mainly to the application of new techniques. It is now possible to examine not only the inferior vena cava and the portal venous system, but also the hepatic veins and the coeliac axis and superior mesenteric artery. Hepatic vein occlusion, portal vein patency and collateral veins, as well as space-occupying lesions, can now be diagnosed with a fair degree of accuracy. These techniques have also helped in the understanding of the altered haemodynamics of portal hypertension and can be used for treatment by intra-arterial perfusion of chemotherapeutic substances. ImagesFig. 1Fig. 2Fig. 3Fig. 4Fig. 5Fig. 6Fig. 7Fig. 8Fig. 9Fig. 10Fig. 11Fig. 12Fig. 13Fig. 14 PMID:5460928
Tasker, Robert C.
Protecting the brain in vulnerable infants undergoing surgery is a central aspect of perioperative care. Understanding the link between blood flow, oxygen delivery and oxygen consumption leads to a more informed approach to bedside care. In some cases, we need to consider how high can we let the partial pressure of carbon dioxide go before we have concerns about risk of increased cerebral blood volume and change in intracranial hydrodynamics? Alternatively, in almost all such cases, we have to address the question of how low can we let the blood pressure drop before we should be concerned about brain perfusion? This review, provides a basic understanding of brain bioenergetics, hemodynamics, hydrodynamics, autoregulation and vascular homeostasis to changes in blood gases that is fundamental to our thinking about bedside care and monitoring. PMID:24331089
Magliulo, Giuseppe; Iannella, Giannicola; Valente, Michele; Greco, Antonio; Appiani, Mario Ciniglio
Objectives Discussion of a rare case of angioleiomyoma involving the geniculate ganglion and the intratemporal facial nerve segment and its surgical treatment. Design Case report. Setting Presence of an expansive lesion englobing the geniculate ganglion without any lesion to the cerebellopontine angle. Participants A 45-year-old man with a grade III facial paralysis according to the House-Brackmann scale of evaluation. Main Outcomes Measure Surgical pathology, radiologic appearance, histological features, and postoperative facial function. Results Removal of the entire lesion was achieved, preserving the anatomic integrity of the nerve; no nerve graft was necessary. Postoperative histology and immunohistochemical studies revealed features indicative of solid vascular leiomyoma. Conclusion Angioleiomyoma should be considered in the differential diagnosis of geniculate ganglion lesions. Optimal postoperative facial function is possible only by preserving the anatomical and functional integrity of the facial nerve. PMID:23943721
Magliulo, Giuseppe; Iannella, Giannicola; Valente, Michele; Greco, Antonio; Ciniglio Appiani, Mario
Objectives Discussion of a rare case of angioleiomyoma involving the geniculate ganglion and the intratemporal facial nerve segment and its surgical treatment. Design Case report. Setting Presence of an expansive lesion englobing the geniculate ganglion without any lesion to the cerebellopontine angle. Participants A 45-year-old man with a grade III facial paralysis according to the House-Brackmann scale of evaluation. Main Outcomes Measure Surgical pathology, radiologic appearance, histological features, and postoperative facial function. Results Removal of the entire lesion was achieved, preserving the anatomic integrity of the nerve; no nerve graft was necessary. Postoperative histology and immunohistochemical studies revealed features indicative of solid vascular leiomyoma. Conclusion Angioleiomyoma should be considered in the differential diagnosis of geniculate ganglion lesions. Optimal postoperative facial function is possible only by preserving the anatomical and functional integrity of the facial nerve.
Ratz, Paul H
Vascular smooth muscle (VSM; see Table 1 for a list of abbreviations) is a heterogeneous biomaterial comprised of cells and extracellular matrix. By surrounding tubes of endothelial cells, VSM forms a regulated network, the vasculature, through which oxygenated blood supplies specialized organs, permitting the development of large multicellular organisms. VSM cells, the engine of the vasculature, house a set of regulated nanomotors that permit rapid stress-development, sustained stress-maintenance and vessel constriction. Viscoelastic materials within, surrounding and attached to VSM cells, comprised largely of polymeric proteins with complex mechanical characteristics, assist the engine with countering loads imposed by the heart pump, and with control of relengthening after constriction. The complexity of this smart material can be reduced by classical mechanical studies combined with circuit modeling using spring and dashpot elements. Evaluation of the mechanical characteristics of VSM requires a more complete understanding of the mechanics and regulation of its biochemical parts, and ultimately, an understanding of how these parts work together to form the machinery of the vascular tree. Current molecular studies provide detailed mechanical data about single polymeric molecules, revealing viscoelasticity and plasticity at the protein domain level, the unique biological slip-catch bond, and a regulated two-step actomyosin power stroke. At the tissue level, new insight into acutely dynamic stress-strain behavior reveals smooth muscle to exhibit adaptive plasticity. At its core, physiology aims to describe the complex interactions of molecular systems, clarifying structure-function relationships and regulation of biological machines. The intent of this review is to provide a comprehensive presentation of one biomachine, VSM.
Supp, D M; Supp, A P; Bell, S M; Boyce, S T
Cultured skin substitutes have been used as adjunctive therapies in the treatment of burns and chronic wounds, but they are limited by lack of a vascular plexus. This deficiency leads to greater time for vascularization compared with native skin autografts and contributes to graft failure. Genetic modification of cultured skin substitutes to enhance vascularization could hypothetically lead to improved wound healing. To address this hypothesis, human keratinocytes were genetically modified by transduction with a replication incompetent retrovirus to overexpress vascular endothelial growth factor, a specific and potent mitogen for endothelial cells. Cultured skin substitutes consisting of collagen-glycosaminoglycan substrates inoculated with human fibroblasts and either vascular endothelial growth factor-modified or control keratinocytes were prepared, and were cultured in vitro for 21 d. Northern blot analysis demonstrated enhanced expression of vascular endothelial growth factor mRNA in genetically modified keratinocytes and in cultured skin substitutes prepared with modified cells. Furthermore, the vascular endothelial growth factor-modified cultured skin substitutes secreted greatly elevated levels of vascular endothelial growth factor protein throughout the entire culture period. The bioactivity of vascular endothelial growth factor protein secreted by the genetically modified cultured skin substitutes was demonstrated using a microvascular endothelial cell growth assay. Vascular endothelial growth factor-modified and control cultured skin substitutes were grafted to full-thickness wounds on athymic mice, and elevated vascular endothelial growth factor mRNA expression was detected in the modified grafts for at least 2 wk after surgery. Vascular endothelial growth factor-modified grafts exhibited increased numbers of dermal blood vessels and decreased time to vascularization compared with controls. These results indicate that genetic modification of
... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Vascular clip. 870.3250 Section 870.3250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3250 Vascular clip. (a) Identification. A...
... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Vascular clip. 870.3250 Section 870.3250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3250 Vascular clip. (a) Identification. A...
... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Vascular clip. 870.3250 Section 870.3250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3250 Vascular clip. (a) Identification. A...
Tisherman, Samuel A
Major blood vessels are in proximity to other vital structures in the neck and base of skull. Infections and tumors of the head and neck can invade vascular structures. Vascular injuries can lead to massive hemorrhage, cerebral ischemia, or stroke. Emergency and definitive management can be challenging. Copyright © 2016 Elsevier Inc. All rights reserved.
Bhat, Vikas; Olmer, Merissa; Joshi, Shweta; Durden, Donald L; Cramer, Thomas J; Barnes, Richard Fw; Ball, Scott T; Hughes, Tudor H; Silva, Mauricio; Luck, James V; Moore, Randy E; Mosnier, Laurent O; von Drygalski, Annette
Hemophilic arthropathy is a debilitating condition that can develop as a consequence of frequent joint bleeding despite adequate clotting factor replacement. The mechanisms leading to repeated spontaneous bleeding are unknown. We investigated synovial, vascular, stromal, and cartilage changes in response to a single induced hemarthrosis in the FVIII-deficient mouse. We found soft-tissue hyperproliferation with marked induction of neoangiogenesis and evolving abnormal vascular architecture. While soft-tissue changes were rapidly reversible, abnormal vascularity persisted for months and, surprisingly, was also seen in uninjured joints. Vascular changes in FVIII-deficient mice involved pronounced remodeling with expression of α-Smooth Muscle Actin (SMA), Endoglin (CD105), and vascular endothelial growth factor, as well as alterations of joint perfusion as determined by in vivo imaging. Vascular architecture changes and pronounced expression of α-SMA appeared unique to hemophilia, as these were not found in joint tissue obtained from mouse models of rheumatoid arthritis and osteoarthritis and from patients with the same conditions. Evidence that vascular changes in hemophilia were significantly associated with bleeding and joint deterioration was obtained prospectively by dynamic in vivo imaging with musculoskeletal ultrasound and power Doppler of 156 joints (elbows, knees, and ankles) in a cohort of 26 patients with hemophilia at baseline and during painful episodes. These observations support the hypothesis that vascular remodeling contributes significantly to bleed propagation and development of hemophilic arthropathy. Based on these findings, the development of molecular targets for angiogenesis inhibition may be considered in this disease.
Bennett, J.P.; Wetmore, C.M.
The geographic relationships among taxonomic groups are important to study to determine patterns of biodiversity and whether or not associations occur between large groups, e.g., birds and vascular plants. This study was undertaken to determine relationships between higher plants and lower plants, specifically vascular plant and lichen floras in nine national parks of the Great Lakes region. No significant relationship was found between vascular plant floras and lichen floras in this area, which spans 1200 km longitudinally, or between an additional 19 areas from North America that were less than 1000 km(2) in area. For areas larger than 1000 km(2), however, a significant positive relationship existed for 33 areas that span one to approximately 150 million km(2). The ratio of numbers of vascular plants to lichens appeared to average just over 6 across the 33 areas. In the Great Lakes parks, between 28-30% of either the vascular plant or lichen species were singletons (occurring in only one park), but the parks that contained the most singletons were not congruent: Isle Royale had the most singleton lichens, while Indiana Dunes had the most vascular plant singletons. Fewer lichen species (2%) than vascular plants (4%) occurred in all nine parks. Latitude appeared to explain some of the variation between the two groups: vascular plants decreased with increasing latitude, while lichens increased.
Shanmugam, P Mahesh; Ramanjulu, Rajesh
Vascular tumors of the retina and choroid can be seen occasionally. In the following article, the key clinical and diagnostic features of the major retinal and choroidal vascular tumors, their systemic associations, and the literature pertaining to the most currently available treatment strategies are reviewed. PMID:25827544
Shanmugam, P Mahesh; Ramanjulu, Rajesh
Vascular tumors of the retina and choroid can be seen occasionally. In the following article, the key clinical and diagnostic features of the major retinal and choroidal vascular tumors, their systemic associations, and the literature pertaining to the most currently available treatment strategies are reviewed.
Alexander, W. C.; Hutchins, P. M.; Kimzey, S. L.
The ionic and cellular feedback relationships operating to effect the vascular decompensatory modifications were examined to reveal procedures for implementing protective measures guarding against vascular collapse when returning from a weightless environment to that of the earth's gravity. The surgical procedures for preparing the rat cremaster, and the fixation methods are described. Abstracts of publications resulting from this research are included.
Farrelly, James S; Stitelman, David H
Obtaining reliable enteral and vascular access constitutes a significant fraction of a pediatric surgeon׳s job. Multiple approaches are available. Given the complicated nature of this patient population multiple complications can also occur. This article discusses the various techniques and potential complications associated with short- and long-term enteral and vascular access. Copyright © 2016 Elsevier Inc. All rights reserved.
Allison, Nathan D; Anderson, Christopher M; Shah, Shinil K; Lally, Kevin P; Hayes-Jordan, Andrea; Tsao, Kuo-Jen; Andrassy, Richard J; Cox, Charles S
Pediatric truncal vascular injuries occur infrequently and have a reported mortality rate of 30% to 50%. This report examines the demographics, mechanisms of injury, associated trauma, and outcome of patients presenting for the past 10 years at a single institution with truncal vascular injuries. A retrospective review (1997-2006) of a pediatric trauma registry at a single institution was undertaken. Seventy-five truncal vascular injuries occurred in 57 patients (age, 12 +/- 3 years); the injury mechanisms were penetrating in 37%. Concomitant injuries occurred with 76%, 62%, and 43% of abdominal, thoracic, and neck vascular injuries, respectively. Nonvascular complications occurred more frequently in patients with abdominal vascular injuries who were hemodynamically unstable on presentation. All patients with thoracic vascular injuries presenting with hemodynamic instability died. In patients with neck vascular injuries, 1 of 2 patients who were hemodynamically unstable died, compared to 1 of 12 patients who died in those who presented hemodynamically stable. Overall survival was 75%. Survival and complications of pediatric truncal vascular injury are related to hemodynamic status at the time of presentation. Associated injuries are higher with trauma involving the abdomen.
Nakagami, Hironori; Osako, Mariana K; Morishita, Ryuichi
Vascular calcification is recently considered as one of the major complications and an independent risk factor of cardiovascular diseases. Although vascular calcification was commonly regarded as a passive process of mineral adsorption or precipitation, it tends to be an active process associated with the expression of growth factors, matrix proteins, and other bone-related proteins. There are 2 main types of vascular calcification. Intimal calcification is found in atherosclerotic plaques and is associated with the vascular events such as myocardial infarction. Medial calcification is usually associated with age and chronic kidney disease patients, which leads to increased vascular stiffness and reduced vascular compliance. Interestingly, our vascular calcification model using ApoE deficient mice showed intima calcification at sites of atherosclerotic plaques under high fat diet with ovariectomy. Thus, lipid metabolism is one of the therapeutic targets to prevent intima calcification of aorta. Previously we reported that ezetimibe significantly prevented atherosclerosis through lipid-lowering effects in ApoE-deficient mice. Based on these findings, we speculate that ezetimibe might prevent aortic intima calcification, which may give us the benefits to decrease vascular events.
Allison, Nathan D.; Anderson, Christopher M.; Shah, Shinil K.; Lally, Kevin P.; Hayes-Jordan, Andrea; Tsao, Kuo-Jen; Andrassy, Richard J.; Cox, Charles S.
Background Pediatric truncal vascular injuries occur infrequently and have a reported mortality rate of 30% to 50%. This report examines the demographics, mechanisms of injury, associated trauma, and outcome of patients presenting for the past 10 years at a single institution with truncal vascular injuries. Methods A retrospective review (1997-2006) of a pediatric trauma registry at a single institution was undertaken. Results Seventy-five truncal vascular injuries occurred in 57 patients (age, 12 ± 3 years); the injury mechanisms were penetrating in 37%. Concomitant injuries occurred with 76%, 62%, and 43% of abdominal, thoracic, and neck vascular injuries, respectively. Nonvascular complications occurred more frequently in patients with abdominal vascular injuries who were hemodynamically unstable on presentation. All patients with thoracic vascular injuries presenting with hemodynamic instability died. In patients with neck vascular injuries, 1 of 2 patients who were hemodynamically unstable died, compared to 1 of 12 patients who died in those who presented hemodynamically stable. Overall survival was 75%. Conclusions Survival and complications of pediatric truncal vascular injury are related to hemodynamic status at the time of presentation. Associated injuries are higher with trauma involving the abdomen. PMID:19853755
Hasegawa, Tomoka; Yamamoto, Tomomaya; Hongo, Hiromi; Tsuboi, Kanako; Amizuka, Norio
Klotho deficient (kl/kl) mice exhibit Möncheberg's vascular calcification in the tunica media due to hyperphosphatemia and hypercalcemia by mediating the disrupted signaling of FGF23/klotho axis. Recent studies have hypothesized the mechanism of medial vascular calcification : Vascular smooth muscle cells acquired excessive intake of phosphate ions undergo a phenotypic differentiation into osteoblasts and induce biological calcification in the tunica media. It is useful to clarify the underlying cellular mechanism of vascular calcification for the development of the treatment and preventive medicine. This review will introduce the histological and ultrastructual findings on medial vascular calcification in kl/kl mice.
Rey, Sergio; Semenza, Gregg L.
The vascular system delivers oxygen and nutrients to every cell in the vertebrate organism. Hypoxia-inducible factor 1 (HIF-1) is a master regulator of hypoxic/ischaemic vascular responses, driving transcriptional activation of hundreds of genes involved in vascular reactivity, angiogenesis, arteriogenesis, and the mobilization and homing of bone marrow-derived angiogenic cells. This review will focus on the pivotal role of HIF-1 in vascular homeostasis, the involvement of HIF-1 in vascular diseases, and recent advances in targeting HIF-1 for therapy in preclinical models. PMID:20164116
Khamassi, Jamel; Bierwisch, Claas; Pelz, Peter
Progress has been made in developing manufacturing technologies which enable the fabrication of artificial vascular networks for tissue cultivation. However, those networks are rudimentary designed with respect to their geometry. This restricts long-term biological functionality of vascular cells which depends on geometry-related fluid mechanical stimuli and the avoidance of vessel occlusion. In the present work, a bioinspired geometry optimization for branchings in artificial vascular networks has been conducted. The analysis could be simplified by exploiting self-similarity properties of the system. Design rules in the form of two geometrical parameters, i.e., the branching angle and the radius ratio of the daughter branches, are derived using the wall shear stress as command variable. The numerical values of these parameters are within the range of experimental observations. Those design rules are not only beneficial for tissue engineering applications. Moreover, they can be used as indicators for diagnoses of vascular diseases or for the layout of vascular grafts.
Teague, Heather L; Ahlman, Mark A; Alavi, Abass; Wagner, Denisa D; Lichtman, Andrew H; Nahrendorf, Matthias; Swirski, Filip K; Nestle, Frank; Gelfand, Joel M; Kaplan, Mariana J; Grinspoon, Steven; Ridker, Paul M; Newby, David E; Tawakol, Ahmed; Fayad, Zahi A; Mehta, Nehal N
Inflammation is a critical factor in early atherosclerosis and its progression to myocardial infarction. The search for valid surrogate markers of arterial vascular inflammation led to the increasing use of positron emission tomography/computed tomography. Indeed, vascular inflammation is associated with future risk for myocardial infarction and can be modulated with short-term therapies, such as statins, that mitigate cardiovascular risk. However, to better understand vascular inflammation and its mechanisms, a panel was recently convened of world experts in immunology, human translational research, and positron emission tomographic vascular imaging. This contemporary review first strives to understand the diverse roles of immune cells implicated in atherogenesis. Next, the authors describe human chronic inflammatory disease models that can help elucidate the pathophysiology of vascular inflammation. Finally, the authors review positron emission tomography-based imaging techniques to characterize the vessel wall in vivo. Published by Elsevier Inc.
Zhang, Li; Xu, Qingbo
A series of studies has been presented in the search for proof of circulating and resident vascular progenitor cells, which can differentiate into endothelial and smooth muscle cells and pericytes in animal and human studies. In terms of pluripotent stem cells, including embryonic stem cells, iPS, and partial-iPS cells, they display a great potential for vascular lineage differentiation. Development of stem cell therapy for treatment of vascular and ischemic diseases remains a major challenging research field. At the present, there is a clear expansion of research into mechanisms of stem cell differentiation into vascular lineages that are tested in animal models. Although there are several clinical trials ongoing that primarily focus on determining the benefits of stem cell transplantation in ischemic heart or peripheral ischemic tissues, intensive investigation for translational aspects of stem cell therapy would be needed. It is a hope that stem cell therapy for vascular diseases could be developed for clinic application in the future.
Miani, S; Boneschi, M; La Penna, A; Erba, M; De Monti, M; Giordanengo, F
Acute vascular abdomen is a severe and life-threatening pathology due to arterial degeneration, leading to hemorrhage or arterial occlusion leading to ischemia. Differential diagnosis of patients with severe abdominal pain and/or shock include several vascular and traumatic diseases, the most common being rupture of abdominal aortic aneurysm (AAA), or less frequently rupture of visceral artery aneurysm. Also acute aortic dissection, iatrogenic injury and acute mesenteric ischemia may lead to acute vascular abdomen. Clinical evaluation of the haemodynamic status of the patient may be very difficult, and may require airway maintenance and ventilation with a rapid treatment of hemorrhagic shock. In the stable patient with an uncertain diagnosis, CT scan, NMR and selective angiography may be helpful in diagnosis before vascular repair. On the contrary, the unstable patient, after hemodynamic resuscitation, must be operated on expeditiously. We present our vascular algorithms, to assess timing of diagnosis and treatment of this severe acute disease.
Zhu, Dongxing; Mackenzie, Neil C. W.; Farquharson, Colin; MacRae, Vicky E.
Vascular calcification has severe clinical consequences and is considered an accurate predictor of future adverse cardiovascular events, including myocardial infarction and stroke. Previously vascular calcification was thought to be a passive process which involved the deposition of calcium and phosphate in arteries and cardiac valves. However, recent studies have shown that vascular calcification is a highly regulated, cell-mediated process similar to bone formation. In this article, we outline the current understanding of key mechanisms governing vascular calcification and highlight the clinical consequences. By understanding better the molecular pathways and genetic circuitry responsible for the pathological mineralization process novel drug targets may be identified and exploited to combat and reduce the detrimental effects of vascular calcification on human health. PMID:22888324
Nagy, Janice A.; Dvorak, Ann M.; Dvorak, Harold F.
It has been known for more than half a century that the tumor microvasculature is hyperpermeable to plasma proteins. However, the identity of the leaky vessels and the consequences of vascular hyperpermeability have received little attention. This article places tumor vascular hyperpermeability in a broader context, relating it to (1) the low-level “basal” permeability of the normal vasculature; (2) the “acute,” short-term hyperpermeability induced by vascular permeability factor/vascular endothelial growth factor (VPF/VEGF-A) and other vascular permeabilizing agents; and (3) the “chronic” hyperpermeability associated with longer-term exposure to agents such as VPF/VEGF-A that accompanies many types of pathological angiogenesis. Leakage of plasma protein-rich fluids is important because it activates the clotting system, depositing an extravascular fibrin gel provisional matrix that serves as the first step in stroma generation. PMID:22355795
Roux, Brianna M; Cheng, Ming-Huei; Brey, Eric M
Vascularization remains one of the most important challenges that must be overcome for tissue engineering to be consistently implemented for reconstruction of large volume bone defects. An extensive vascular network is needed for transport of nutrients, waste and progenitor cells required for remodelling and repair. A variety of tissue engineering strategies have been investigated in an attempt to vascularize tissues, including those applying cells, soluble factor delivery strategies, novel design and optimization of bio-active materials, vascular assembly pre-implantation and surgical techniques. However, many of these strategies face substantial barriers that must be overcome prior to their ultimate translation into clinical application. In this review recent progress in engineering vascularized bone will be presented with an emphasis on clinical feasibility. PMID:25877690
Bangalore, Sripal; Arora, Nipun; Resnic, Frederic S.
Background Vascular closure devices (VCDs) are effective at reducing the time to ambulation for patients undergoing cardiac catheterization procedures, and in reducing the risk of vascular complications in selected patient cohorts. However, the frequency and consequence of failure of VCDs is not well defined. Methods and Results From a prospective registry of consecutive patients undergoing cardiac catheterization at our center, 9823 patients who received either a collagen-plug (Angio-Seal®) based or a suture-based (Perclose®) VCD were selected for the study. VCD failure was defined as unsuccessful deployment or failure to achieve hemostasis. Major vascular complication was defined as any retroperitoneal hemorrhage, limb ischemia, or any surgical repair. Minor vascular complication was defined as any groin bleeding, hematoma (≥ 5 cm), pseudoaneurysm or arteriovenous fistula. ‘Any’ vascular complication was defined as either a major or minor vascular complication. Among the 9823 patients in the study, VCD failed in 268 (2.7%; 2.3% diagnostic vs. 3.0% PCI; P = 0.029) patients. Patients with VCD failure had significantly increased risk of any (6.7% vs. 1.4%; P < 0.0001), major (1.9% vs. 0.6%; P = 0.006) or minor (6.0% vs. 1.1%; P < 0.0001) vascular complication compared with the group with successful deployment of VCD. The increased risk of vascular complication was unchanged in a propensity score matched cohort. Conclusions In contemporary practice, VCD failure is rare but when it does fail, it is associated with significant increase in the risk of vascular complications. Patients with VCD failure should be closely monitored to prevent vascular complications. PMID:20031773
Hata, Kai W; Propper, Brandon; Rich, Norman
The management of arterial injuries has evolved from simple cauterization of the time of Ambrose Paré to the more complex repairs of today. Through history there has been much learned from combat regarding the management of vascular injuries. Starting in World War I, vascular registries have been established to further study and refine the management of these injuries. One of the most pivotal registries was the Vietnam Vascular Registry established by Dr Norman Rich. The lessons learned from these registries have been carried on to the current conflicts with the establishment of the Global War on Terror Vascular Initiative. We compare 100 lower extremity vascular injuries from the Vietnam Vascular Registry to 100 injuries in the Global War on Terror Vascular Initiative database as we continue to improve the future with lessons from our past.
Ziegler, Kenneth R; Dardik, Alan
The Vascular Research Initiatives Conference (VRIC) is an annual conference organized by the Society for Vascular Surgery (SVS). The 2011 VRIC was held in Chicago (IL, USA) to precede and coincide with the first day of the meeting of the Council on Arteriosclerosis, Thrombosis and Vascular Biology (ATVB) of the American Heart Association. The event is designed to present world class vascular research results, encourage collaboration between vascular surgeons and basic scientists in related disciplines, as well as to stimulate interest in research among aspiring academic vascular surgeons. The 2011 VRIC featured plenary sessions addressing peripheral arterial disease, vascular endothelium and thrombosis, aneurysms, and stem cells and tissue engineering. Recipients of the SVS partner grants with the National Institutes of Health K08 awardees presented their progress reports, and keynote addresses were given by Linda Graham and Frank LoGerfo.
Tucker, A.; Penney, D.G. Wayne State Univ., Detroit, MI )
Exposure of adult and neonatal rats to high altitude increases pulmonary vascular responsiveness during the exposure. A study was undertaken to determine if a short exposure of neonatal rats to either high-altitude or carbon monoxide (CO) hypoxia would cause persistent alterations in pulmonary vascular responsiveness postexposure. One-day-old male Sprague-Dawley rats were obtained as 16 litters of 10-12 pups each. At 2 days of age, 4 litters were exposed to CO (500 ppm) for 32 days, and 4 litters were exposed to ambient air (AIR) in Detroit (200 m). Another 4 litters were exposed to 3500 m altitude (ALT) in a chamber for 32 days, and 3 litters were exposed to ambient conditions in Fort Collins (CON, 1524 m). After the exposures, all rats were maintained at 1524 m. At 2, 40, 76 and 112 days postexposure, lungs were isolated and perfused with Earle's salt solution (+Ficoll, 4 g%). Pulmonary vascular responsiveness was assessed by dose responses to angiotensin II (AII, 0.025-0.40 [mu]g) and acute hypoxia (3% O[sub 2] for 3 min). AII responses were higher in ALT vs CON rats at 2 and 40 days postexposure, but no differences were noted between CO and AIR rats. Baseline pulmonary vascular resistance and pulmonary arterial pressure (in isolated lungs) were higher in ALT rats at all four ages compared to the other three groups. Both the ALT and CO rats displayed hypertrophy of the right ventricle (RV) and the left ventricle (LV) at the termination of treatment and elevated hematocrit. LV hypertrophy and polycythemia regressed with time, but RV hypertrophy remained significant in the ALT rats through 112 days postexposure. The results indicate that neonatal exposure to ALT, but no CO, causes a persistent increase in pulmonary vascular responsiveness and RV hypertrophy for at least 112 days after termination of the exposure. 40 refs., 3 figs., 2 tabs.
Casas, Meritxell; Calvet, Xavier; Vergara, Mercedes; Bella, Maria Rosa; Junquera, Félix; Martinez-Bauer, Eva; Campo, Rafael
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.
Lubberts, S; Boer, H; Altena, R; Meijer, C; van Roon, A M; Zwart, N; Oosting, S F; Kamphuisen, P W; Nuver, J; Smit, A J; Mulder, A B; Lefrandt, J D; Gietema, J A
Metastatic testicular cancer (TC) can be cured with bleomycin, etoposide and cisplatin (BEP) chemotherapy. This comes at the price of an increased cardiovascular disease risk, not only years afterwards, but also during and shortly after chemotherapy. To prevent cardiovascular events, high-risk patients should be identified. The aim of this study was to assess BEP-chemotherapy induced vascular damage and to find risk factors for early vascular events. A prospective cohort study was performed in (B)EP treated TC patients. Development of venous and arterial vascular events was assessed. Vascular damage markers (von Willebrand factor [vWF], coagulation factor VIII [FVIII], intima media thickness [IMT]) and cardiovascular risk factors were assessed before and until 1 year after chemotherapy. Before start of chemotherapy a vascular fingerprint was estimated. Presence of ≥3 risk factors was defined as high-risk vascular fingerprint: body mass index >25 kg/m(2), current smoking, blood pressure >140/90 mm Hg, total cholesterol >5.1 and/or low-density lipoprotein >2.5 mmol/L or glucose ≥7 mmol/L. Seventy-three patients were included. Eight (11%) developed vascular events (four arterial events, four pulmonary embolisms). vWF and FVIII increased during chemotherapy, especially in patients with vascular events. Sixteen patients (22%) had a high-risk vascular fingerprint before start of chemotherapy. These patients had arterial events more often (3/16 [19%] versus 1/57 [2%]; p = 0.031) and higher vWF levels and IMT. Endothelial activation and upregulation of procoagulant activity seem important mechanisms involved in early (B)EP-chemotherapy-induced vascular events. Before chemotherapy, a quarter already had cardiovascular risk factors. A vascular fingerprint could identify patients at risk for arterial events. This vascular fingerprint, when validated, can be used as a tool to select patients who may benefit from preventive strategies. Copyright © 2016 Elsevier Ltd
Chemically induced vascular toxicity during embryonic development can result in a wide range of adverse prenatal outcomes. We used information from genetic mouse models linked to phenotypic outcomes and a vascular toxicity knowledge base to construct an embryonic vascular disrupt...
Hai, Pengfei; Zhou, Yong; Liang, Jinyang; Li, Chiye; Wang, Lihong V.
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.
Mercado-Pagán, Ángel E.; Stahl, Alexander M.; Shanjani, Yaser; Yang, Yunzhi
Vascularization of large bone grafts is one of the main challenges of bone tissue engineering (BTE), and has held back the clinical translation of engineered bone constructs for two decades so far. The ultimate goal of vascularized BTE constructs is to provide a bone environment rich in functional vascular networks to achieve efficient osseointegration and accelerate restoration of function after implantation. To attain both structural and vascular integration of the grafts, a large number of biomaterials, cells, and biological cues have been evaluated. This review will present biological considerations for bone function restoration, contemporary approaches for clinical salvage of large bone defects and their limitations, state-of-the-art research on the development of vascularized bone constructs, and perspectives on evaluating and implementing novel BTE grafts in clinical practice. Success will depend on achieving full graft integration at multiple hierarchical levels, both between the individual graft components as well as between the implanted constructs and their surrounding host tissues. The paradigm of vascularized tissue constructs could not only revolutionize the progress of bone tissue engineering, but could also be readily applied to other fields in regenerative medicine for the development of new innovative vascularized tissue designs. PMID:25616591
Baeten, J T; Lilly, B
The Notch signaling pathway is a highly conserved pathway involved in cell fate determination in embryonic development and also functions in the regulation of physiological processes in several systems. It plays an especially important role in vascular development and physiology by influencing angiogenesis, vessel patterning, arterial/venous specification, and vascular smooth muscle biology. Aberrant or dysregulated Notch signaling is the cause of or a contributing factor to many vascular disorders, including inherited vascular diseases, such as cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, associated with degeneration of the smooth muscle layer in cerebral arteries. Like most signaling pathways, the Notch signaling axis is influenced by complex interactions with mediators of other signaling pathways. This complexity is also compounded by different members of the Notch family having both overlapping and unique functions. Thus, it is vital to fully understand the roles and interactions of each Notch family member in order to effectively and specifically target their exact contributions to vascular disease. In this chapter, we will review the Notch signaling pathway in vascular smooth muscle cells as it relates to vascular development and human disease.
Numerous studies have indicated an increased risk of vascular disease among migraineurs. Alterations in endothelial and arterial function, which predispose to atherosclerosis and cardiovascular diseases, have been suggested as an important link between migraine and vascular disease. However, the available evidence is inconsistent. We aimed to review and summarize the published evidence about the peripheral vascular dysfunction of migraineurs. We systematically searched in BIOSIS, the Cochrane database, Embase, Google scholar, ISI Web of Science, and Medline to identify articles, published up to April 2013, evaluating the endothelial and arterial function of migraineurs. Several lines of evidence for vascular dysfunction were reported in migraineurs. Findings regarding endothelial function are particularly controversial since studies variously indicated the presence of endothelial dysfunction in migraineurs, the absence of any difference in endothelial function between migraineurs and non-migraineurs, and even an enhanced endothelial function in migraineurs. Reports on arterial function are more consistent and suggest that functional properties of large arteries are altered in migraineurs. Peripheral vascular function, particularly arterial function, is a promising non-invasive indicator of the vascular health of subjects with migraine. However, further targeted research is needed to understand whether altered arterial function explains the increased risk of vascular disease among patients with migraine. PMID:24083826
Wang, Mi; Wang, Mei; Gan, Liang-Ying; Li, Si-Jun; Hong, Nan; Zhang, Meng
The objective was to investigate the status of vascular calcification, and to explore factors influencing vascular calcification in maintenance hemodialysis patients. Vascular calcification was quantitatively evaluated using radiographic films of the abdomen, pelvis and hands. Plasma fetuin-A and other parameters related to calcification were examined. 33/50 cases of vascular calcification were identified by radiographic film. Calcifications of the abdominal aorta and peripheral muscular arteries were seen in 90.9 and 36.4%. Patients with moderate to severe calcification were older, more likely to be male, had lower diastolic blood pressure and fetuin-A levels, and a higher incidence of diabetes than those with mild calcification. Logistic regression analysis showed that diabetes and plasma fetuin-A were independent risk factors for vascular calcification. Vascular calcification was present in a large proportion of maintenance hemodialysis patients, most frequently in the abdominal aorta. Diabetes and plasma fetuin-A levels were independent risk factors for vascular calcification in maintenance hemodialysis patients. (c) 2009 S. Karger AG, Basel.
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.
Siddique, Muhammad Khalid; Majeed, Shahid; Irfan, Muhammad; Ahmad, Nisar
To describe the different presentation, diagnostic evaluation, management and outcome of complications of missed vascular injuries. A case series. Combined Military Hospital, Rawalpindi and Combined Military Hospital, Kharian Cantt, from June 2009 to June 2012. All the patients with vascular injuries missed at the time of causative trauma who reported during this study period were included. Patients presented with acute vascular injuries and iatrogenic aneurysm at the vascular anastomosis site were excluded. All cases were evaluated with either CT or conventional angiography and managed with various open vascular surgical techniques and their results were assessed. Twenty eight patients with missed vascular injury underwent various vascular repairs. Age of patients ranged from 16 to 78 years (mean = 33.7 ± 15.4 years). Male to female ratio was 6:1. Twelve (42.8%) patients presented with pseudoaneurysm alone, 10 (35.7%) with traumatic arteriovenous fistulae, 4 (14.3%) with post-traumatic thrombosis and occlusion and 2 (7.1%) with pseudoaneurysm and hemorrhage. Penetrating injuries were the commonest cause in 19 (67.8%). The time interval between injury and presentation in hospital ranged from 2 to 1300 weeks (mean 228 weeks). Lower limb vessels were affected in 20 (71.4%), the upper limb in 5 (17.8%) and neck vessels in 3 (10.7%). Superficial femoral artery was the most frequently involved artery in 9 (32.1%) cases. Interposition reverse autogenous saphenous vein graft was most common type of repair in all types of missed vascular injuries. One (3.5%) patient had amputation after secondary hemorrhage. Low velocity penetrating trauma was the common cause of missed vascular injury. Pseudoaneurysm was the most common presentation.
Yasunari, K; Kohno, M; Yokokawa, K; Horio, T; Kano, H; Takeda, T
The modulation of dopamine DA1 receptors of cultured rat renal arterial smooth muscle cells by phorbol ester, glucocorticoid and sodium chloride was studied. The extent of [3H]Sch-23390 binding to phorbol ester-treated cell was increased without any change in the dissociation constant (Kd). At a concentration of 10 nmol/l, the synthetic glucocorticoid dexamethasone increased maximum receptor binding (Bmax) but had no effect on the Kd. 100 mmol/l sodium chloride did not change Bmax, but increased the Kd for DA1 receptor. The production of cAMP in response to DA1 receptor stimulation was enhanced without any change of the adenylate cyclase activity. The glucocorticoid effect on DA1 of arterial smooth muscle cells became apparent after hours of incubation in the presence of the steroid and was significantly inhibited by cycloheximide (10 micrograms/ml) and by the glucocorticoid receptor antagonist RU-38486, indicating that the effect required protein synthesis through glucocorticoid receptors. Treatment of cells with 1 mumol/l dexamethasone for 24 h increased basal and DA1-stimulated adenylate cyclase activity. Basal adenylate cyclase was decreased by sodium chloride in a dose-dependent manner. These results suggest differential control of DA1 receptors on vascular smooth muscle cells by protein kinase C, glucocorticoid or sodium chloride.
Schiele, Thomas M; Krötz, Florian; Klauss, Volker
Restenosis is the limiting entity following coronary angioplasty. It is associated with significant morbidity, mortality and cost, and thus represents a major clinical and economical problem. Despite technical improvements, restenosis after conventional balloon angioplasty occurs in 30 - 60% of cases. Coronary stenting was able to reduce the incidence by approximately 30%; nevertheless, some 250,000 patients experience in-stent restenotic lesions/year worldwide. In-stent restenosis has been recognised as very difficult to manage, with a repeat restenosis rate of 50%, regardless of the angioplasty device used. So far, only vascular brachytherapy has convincingly reduced the incidence of repeat in-stent restenosis (by 50%) and thus, has emerged as the gold standard of therapy. The introduction of drug-eluting stents has shown a great deal of promise for the treatment of both de novo and restenotic lesions, with reported restenosis rates of < 10%, and benefit for virtually all patient subsets at a higher risk of restenosis. This review outlines the pathophysiology, epidemiology and predictors of the restenosis process, and places emphasis on the various treatment options for its prevention and therapy.
Gibbons, Christopher P
Neurological problems are common in patients undergoing haemodialysis. Over 60% of patients will suffer from symptoms of underlying polyneuropathy due to uraemia or diabetes. Others will have subclinical disease demonstrable by nerve conduction studies. Nerve injury following haemodialysis access surgery is underreported. However, sensory nerve lesions are probably common after most vascular access procedures but are rarely debilitating. Nerve compression syndromes such as carpal tunnel and ulnar compression syndromes are common, especially in patients who have been on dialysis for some years and at least some of these are related to or exacerbated by the access. Recognition is essential as they are eminently treatable by decompression surgery. Tourniquet use appears to be safe for carpal tunnel or ulnar nerve decompression surgery. Ischaemic monomelic neuropathy (IMN) is rare but follows a period of ischaemia during or as a result of access surgery, most commonly to construct a brachial arteriovenous fistula or graft. It is characterised by intense pain, out of proportion to any ischaemia, involves all of the upper limb nerves and may progress to involve the motor nerves eventually resulting in a useless clawed hand. It requires prompt treatment of any residual ischaemia after access creation, if necessary by access ligation, as in the established syndrome, like the even rarer complication of reflex sympathetic dystrophy, it is very difficult to offer any useful treatment other than symptomatic relief and physiotherapy.
Cascaval, Radu C; D'Apice, Ciro; D'Arienzo, Maria Pia; Manzo, Rosanna
The development of mathematical models for studying phenomena observed in vascular networks is very useful for its potential applications in medicine and physiology. Detailed 3D studies of flow in the arterial system based on the Navier-Stokes equations require high computational power, hence reduced models are often used, both for the constitutive laws and the spatial domain. In order to capture the major features of the phenomena under study, such as variations in arterial pressure and flow velocity, the resulting PDE models on networks require appropriate junction and boundary conditions. Instead of considering an entire network, we simulate portions of the latter and use inflow and outflow conditions which realistically mimic the behavior of the network that has not been included in the spatial domain. The resulting PDEs are solved numerically using a discontinuous Galerkin scheme for the spatial and Adam-Bashforth method for the temporal discretization. The aim is to study the effect of truncation to the flow in the root edge of a fractal network, the effect of adding or subtracting an edge to a given network, and optimal control strategies on a network in the event of a blockage or unblockage of an edge or of an entire subtree.
Leavitt, M B
Twenty-one families were observed in a 3-month study to assess family coping with major vascular surgery and recovery. Analysis of family measures data (the Family APGAR, the Family Inventory of Resource for Management, and the Family Crisis Oriented Personal Evaluation Scales) was combined with grounded theory method to assess family responses over time and recovery outcomes. Containment emerged as the major conceptual category of the grounded theory. Containment refers to a constellation of constructed meanings for events and behavioral responses used by families to regulate the impact of the surgical crisis and reduce family disruption. This "contained" coping pattern was manifested in families' avoidant behaviors and narrow definitions of the problem: that is, they defined their situation in terms of the surgical repair as cure rather than palliative intervention for a chronic, progressive disease. Situational factors such as the insidious development of the illness and the primary focus of care providers in the hospital on surgical care (allowing families' narrow definitions of their situation to remain unchallenged) also contributed to containment. Containment resulted in poor risk factor management as a major recovery outcome. Isolation and family conflict were evident throughout the recovery period. Concerns generated by continued evidence of morbidity during recovery contributed to a developing awareness of underlying disease, and diminishing containment when this growing awareness was openly shared within the family. Significant findings of the family measures analysis were compared with the grounded theory of the qualitative data. Each corroborated the other in key dimensions.
Boughner, Derek R.; Dunmore-Buyze, Joy; Heenatigala, Dino; Lohmann, Tara; Ellis, Chris G.
Cell membrane remnants represent a probable nucleation site for calcium deposition in bioprosthetic heart valves. Calcification is a primary failure mode of both bovine pericardial and porcine aortic heterograft bioprosthesis but the nonuniform pattern of calcium distribution within the tissue remains unexplained. Searching for a likely cellular source, we considered the possibility of a previously overlooked small blood vessel network. Using a videomicroscopy technique, we examined 5 matched pairs of porcine aortic and pulmonary valves and 14 samples from 6 bovine pericardia. Tissue was placed on a Leitz Metallux microscope and transilluminated with a 75 watt mercury lamp. Video images were obtained using a silicon intensified target camera equipped with a 431 nm interference filter to maximize contrast of red cells trapped in a capillary microvasculature. Video images were recorded for analysis on a Silicon Graphics Image Analysis work station equipped with a video frame grabber. For porcine valves, the technique demonstrated a vascular bed in the central spongiosa at cusp bases with vessel sizes from 6-80 micrometers . Bovine pericardium differed with a more uniform distribution of 7-100 micrometers vessels residing centrally. Thus, small blood vessel endothelial cells provide a potential explanation patterns of bioprosthetic calcification.
Yang, Chun; Du, Yi-Kuan; Wu, Jian-Bin; Wang, Jun; Luan, Ping; Yang, Qin-Lao; Yuan, Lin
The anatomical basis for the concept of acupuncture points/meridians in traditional Chinese medicine (TCM) has not been resolved. This paper reviews the fascia research progress and the relationship among acupuncture points/meridians, primo vascular system (PVS), and fascia. Fascia is as a covering, with common origins of layers of the fascial system despite diverse names for individual parts. Fascia assists gliding and fluid flow and holds memory and is highly innervated. Fascia is intimately involved with nourishment of all cells of the body, including those of disease and cancer. The human body's fascia network may be the physical substrate represented by the meridians of TCM. The PVS is a newly found circulatory system; recent increased interest has led to new research and new discoveries in the anatomical and functional aspects of the PVS. The fasciology theory provides new insights into the physiological effects of acupuncture needling on basic cellular mechanisms including connective tissue mechanotransduction and regeneration. This view represents a theoretical basis and means for applying modern biomedical research to examining TCM principles and therapies, and it favors a holistic approach to diagnosis and treatment.
Yang, Chun; Du, Yi-kuan; Wu, Jian-bin; Wang, Jun; Luan, Ping; Yang, Qin-lao; Yuan, Lin
The anatomical basis for the concept of acupuncture points/meridians in traditional Chinese medicine (TCM) has not been resolved. This paper reviews the fascia research progress and the relationship among acupuncture points/meridians, primo vascular system (PVS), and fascia. Fascia is as a covering, with common origins of layers of the fascial system despite diverse names for individual parts. Fascia assists gliding and fluid flow and holds memory and is highly innervated. Fascia is intimately involved with nourishment of all cells of the body, including those of disease and cancer. The human body's fascia network may be the physical substrate represented by the meridians of TCM. The PVS is a newly found circulatory system; recent increased interest has led to new research and new discoveries in the anatomical and functional aspects of the PVS. The fasciology theory provides new insights into the physiological effects of acupuncture needling on basic cellular mechanisms including connective tissue mechanotransduction and regeneration. This view represents a theoretical basis and means for applying modern biomedical research to examining TCM principles and therapies, and it favors a holistic approach to diagnosis and treatment. PMID:26379741
Dooley, D M
Fifty per cent of patients diagnosed as having multiple sclerosis, primary lateral sclerosis, or hereditary spinocerebellar disorders were observed to have enduring favorable changes in neurological function during the 15 to 27 months they have been followed. The patients who were the least severely disabled were benefitted the most by the stimulation and made the most rapid progress. For example, the patient having only an ataxic or a spastic gait typically was observed to improve faster than the patient having both an ataxic and a spastic gait. The long term effect of electrostimulation of the spinal cord on these patients is unknown. The purpose of the stimulation is to attempt to obtain an improvement in neurological function so that the patient may experience a better life style. It is not thought that the electrical current has any effect on the basic disease process. Electrostimulation over the posterior spinal roots and spinal cord, although not new, has not been used extensively for the treatment of patients with arterial disease. The patients who have responded the most dramatically to electrostimulation are those with vasospastic disorders. A larger percentage of patients showed a greater response to implanted stimulation than to transcutaneous stimulation. Electrostimulation of the nervous system is not designed to replace standard therapeutic measures of treatment of patients with vascular disease, but to supplement them.
Seals, Douglas R; Walker, Ashley E; Pierce, Gary L; Lesniewski, Lisa A
Age is the major risk factor for cardiovascular diseases (CVD) and this is attributable in part to stiffening of large elastic arteries and development of vascular endothelial dysfunction (e.g. impaired endothelium-dependent dilatation, EDD). In contrast, regular aerobic exercise is associated with reduced risk of CVD. Endurance exercise-trained middle-aged/older adults demonstrate lower large elastic artery stiffness and greater EDD than their sedentary peers. With daily brisk walking, previously sedentary middle-aged/older adults show reduced stiffness and improved EDD. The mechanisms underlying the effects of regular aerobic exercise on large elastic artery stiffness with ageing are largely unknown, but are likely to include changes to the composition of the arterial wall. Enhanced EDD in older adults who exercise is mediated by increased nitric oxide (NO) bioavailability associated with reduced oxidative stress. Arteries from old rodents that perform regular aerobic exercise demonstrate increased expression and activity of endothelial NO synthase, reduced oxidative damage associated with reduced expression and activity of the oxidant enzyme NADPH oxidase, and increased activity of the antioxidant enzyme superoxide dismutase. Aerobic exercise also may protect arteries with ageing by increasing resistance to the effects of other CVD risk factors like LDL-cholesterol. Habitual aerobic exercise is an effective strategy to combat arterial ageing. PMID:19723776
Osol, George; Mandala, Maurizio
Sufficient uteroplacental blood flow is essential for normal pregnancy outcome and is accomplished by the coordinated growth and remodeling of the entire uterine circulation, as well as the creation of a new fetal vascular organ: the placenta. The process of remodeling involves a number of cellular processes, including hyperplasia and hypertrophy, rearrangement of existing elements, and changes in extracellular matrix. In this review, we provide information on uterine blood flow increases during pregnancy, the influence of placentation type on the distribution of uterine vascular resistance, consideration of the patterns, nature, and extent of maternal uterine vascular remodeling during pregnancy, and what is known about the underlying cellular mechanisms. PMID:19196652
Romeo, U.; Rocchetti, F.; Gaimari, G.; Tenore, G.; Palaia, G.; Lo Giudice, G.
Vascular malformations are a very heterogeneous group of circulatory system's diseases that can involve different kind of vessels: arterial, venous or lymphatic ones. Many treatments, such as conventional surgery, embolization, steroid therapy and laser therapy, are available for vascular lesions. The laser approach relies more therapeutic techniques: the transmucosal thermophotocoagulation, intralesional photocoagulation, the excisional biopsy. Today laser is demonstrated to be the gold standard technique to treat vascular lesions that allows a safe and efficient treatment and a lower post-operative healing time. The only disadvantage is the risk of carbonization that could be avoided by using the multiple-spot single pulsed wave technique.
Heller, G; Savolainen, H; Widmer, M K; Makaloski, V; Menth, M; Schmidli, J
Since the first use of vacuum-assisted therapy (V.A.C.) in wound care, the indications of this therapy have rapidly expanded. Vascular surgery presents many types of problematic wounds. In the current cost conscious atmosphere, there is a great demand for simple and effective therapies. The V.A.C. system has a lot of potential in the management of vascular wounds. In this article we present indications for vacuum-assisted therapy in vascular surgery: chronic leg ulcers, mesh skin graft, wound care after fasciotomy for compartment syndrome, problematic inguinal wound, false aneurysms, diabetic foot gangrene and amputations with marginal circulations.
Children with vascular malformations are best managed with a multidisciplinary team of specialists. Interventional radiology may deliver primary treatment such as staged sclerotherapy and embolization for malformations that are poor candidates for primary surgical resection or play a supportive role such as preoperative or intraoperative embolization. A thorough understanding of vascular morphology and flow dynamics is imperative to choosing the best treatment tool and technique. In this review, the author discusses the selection of techniques and tools used to treat vascular malformations based on their angiographic morphology. PMID:25045335
Martin-Vaquero, Paula; Moore, Sarah A; Wolk, Kendra E; Oglesbee, Michael J
An 11-year-old castrated male domestic medium hair cat was presented with neurological signs consistent with a right thalamocortical lesion. Computed tomography (CT) images revealed a heterogeneously, hyperattenuating, poorly contrast enhancing intra-axial mass within the right lateral ventricle. The histological diagnosis at post-mortem examination was vascular hamartoma with hemorrhage and necrosis. This is the first report of a vascular hamartoma affecting the thalamocortex in a geriatric cat. Also, this is the first time that CT images of a feline cerebral vascular hamartoma have been reported. PMID:21277244
Dubey, Indu Bhushan; Sharma, Anuj; Singh, Ajay Kumar; Mohanty, Debajyoti
A 30-year-old man presented to the Department of Surgery with a painful groin swelling on right side. Exploration revealed a reddish-blue hemangiomatous mass in the scrotum extending through inguinal canal into the retroperitoneum. On further dissection swelling was found to be originating from right external iliac vein. The swelling was excised after ligating all vascular connections. The histopathological examination of excised mass confirmed the diagnosis of venous variety of vascular malformation. This is the first reported case of vascular malformation arising from retroperitoneum and extending into inguinoscrotal region, presenting as incarcerated inguinal hernia.
Jono, Shuichi; Shioi, Atsushi; Ikari, Yuji; Nishizawa, Yoshiki
Vascular calcification is often encountered in advanced atherosclerotic lesions and is a common consequence of aging. Calcification of the coronary arteries has been positively correlated with coronary atherosclerotic plaque burden, increased risk of myocardial infarction, and plaque instability. Chronic kidney disease (CKD) patients have two to five times more coronary artery calcification than healthy age-matched individuals. Vascular calcification is a strong prognostic marker of cardiovascular disease mortality in CKD patients. Vascular calcification has long been considered to be a passive, degenerative, and end-stage process of atherosclerosis and inflammation. However, recent evidence indicates that bone matrix proteins such as osteopontin, matrix Gla protein (MGP), and osteocalcin are expressed in calcified atherosclerotic lesions, and that calcium-regulating hormones such as vitamin D3 and parathyroid hormone-related protein regulate vascular calcification in in vitro vascular calcification models based on cultured aortic smooth muscle cells. These findings suggest that vascular calcification is an actively regulated process similar to osteogenesis, and that bone-associated proteins may be involved in the development of vascular calcification. The pathogenesis of vascular calcification in CKD is not well understood and is almost multifactorial. In CKD patients, several studies have found associations of both traditional risk factors, such as hypertension, hyperlipidemia, and diabetes, and uremic-specific risk factors with vascular calcification. Most patients with progressive CKD develop hyperphosphatemia. An elevated phosphate level is an important risk factor for the development of calcification and cardiovascular mortality in CKD patients. Thus, it is hypothesized that an important regulator of vascular calcification is the level of inorganic phosphate. In order to test this hypothesis, we characterized the response of human smooth muscle cell (HSMC
Zanow, J; Settmacher, U
Prosthetic arteriovenous grafts have an inferior patency rate and greater morbidity than those with autogenous vessels and are therefore considered as secondary or tertiary vascular access for hemodialysis in patients with fatigued or unsuitable superficial arm veins. Prior access planning in accordance of patient characteristics, careful operative procedure and appropriate revision of complications can ensure long-term functioning of a vascular access using a large variety of possible prosthetic conduits. Arteriovenous grafts remain essential in vascular access surgery and their role may be increasing with higher comorbidities of patients and should be preferred to tunnelled cuffed catheters. This article reviews the indications, alternative configurations and characteristics of arteriovenous grafts.
Sharma, Parikshit S; Padala, Santosh K; Gunda, Sampath; Koneru, Jayanthi N; Ellenbogen, Kenneth A
Vascular access related complications are the most common complications from catheter based EP procedures and have been reported to occur in 1-13% of cases. We prospectively assessed vascular complications in a large series of consecutive patients undergoing catheter based electrophysiologic (EP) procedures with ultrasound (US) guided vascular access versus conventional access. Consecutive patients undergoing catheter ablation procedures at VCU medical center were included. US guided access was obtained in all cases starting June 2015 (US group) while modified Seldinger technique without US guidance (non-US group) was used in cases prior to this date. All vascular complications were recorded for a 30-day period after the procedure. A total of 689 patients underwent 720 procedures. Ablations for ventricular tachyarrhythmias (ventricular tachycardia: VT, premature ventricular contractions: PVCs) accounted for 89 (12%) cases; atrial fibrillation (AF) ablations accounted for 328 procedures (46%) and other catheter based procedures accounted for 42% of cases. A significantly higher incidence of complications was noted in the non-US group compared with the US group (19 [5.3%] vs. 4 [1.1%], respectively, P = 0.002). Major complications were also higher among the non-US group (9 [2.5%] vs. 2 [0.6%], P = 0.03). Increasing age (P = 0.04) and non-US guided vascular access (P = 0.002) were associated with a higher risk of vascular access complications. In a large series of patients undergoing catheter based EP procedures for cardiac arrhythmias, US guided vascular access was associated with a significantly decreased 30-day risk of vascular complications. © 2016 Wiley Periodicals, Inc.
Hoeger, P H; Colmenero, I
Vascular anomalies can be subdivided into vascular tumours and vascular malformations (VMs). While most VMs are present at birth and do not exhibit significant postnatal growth, vascular tumours are characterized by their dynamics of growth and (sometimes) spontaneous regression. This review focuses on benign vascular tumours other than infantile haemangiomas (IHs), namely pyogenic granuloma, eruptive pseudoangiomatosis, glomangioma, rapidly involuting and noninvoluting congenital haemangioma, verrucous haemangioma and spindle cell haemangioma. While some of them bear clinical resemblance to IH, they can be separated by age of appearance, growth characteristics and/or negative staining for glucose transporter 1. Separation of these tumours from IH is necessary because their outcome and therapeutic options are different. Semimalignant and malignant vascular tumours will be addressed in a separate review.
Stowe, G C; Zakov, Z N; Albert, D M; Smith, T R; Sang, D N; Craft, J L
The occurrence of vascular basophilia in ocular tumors has been a selective histologic feature of retinoblastomas. We recently observed a metastatic oat-cell carcinoma to the choroid which also demonstrated such a vascular hematoxyphilia. Histologic review of a variety of ocular and orbital metastatic carcinomas failed to yield a similar basophilic pattern. Examination of 100 consecutive retinoblastomas for vascular basophilia revealed an incidence of 6.0%. Similar material was not seen in any of 125 melanomas, including 10 with areas of necrosis. Histochemical studies showed the basophilic material to be DNA, and electron microscopy revealed the nuclear debris of pyknotic tumor cells to be continuous with identical material surrounding the adjacent blood vessels. The pathogenesis of vascular deposition of DNA in these two ocular tumors remains unclear. This finding most likely represents a form of tumor activity requiring comparatively healthy blood vessels to adequately precipitate liberated nucleic acids being filtered from the necrotic and degenerating tumor tissue.
Teo, Siew T; Yung, Yun C; Herr, Deron R; Chun, Jerold
Lysophosphatidic acid (LPA) is a small signaling lipid that is capable of stimulating a plethora of different cellular responses through the activation of its family of cognate G protein-coupled receptors. LPA mediates a wide range of biological effects in many tissue types that have been recently reviewed; however, its effects on vasculature development and function have received comparatively less examination. In this review, literature on the actions of LPA in three main aspects of vascular development (vasculogenesis, angiogenesis, and vascular maturation) is discussed. In addition, evidence for the roles of LPA signaling in the formation of secondary vascular structures, such as the blood brain barrier, is considered, consistent with significant roles for LPA signaling in vascular development, function, and disease.
Blackburn, Michael R
In this issue of Blood, Riegel and colleagues demonstrate that inflammatory stimuli induce the expression of the P2Y6 receptor on the vascular endothelium where it serves to enhance systemic inflammatory responses.
Liu, Juan; Zheng, Huaiyuan; Poh, Patrina S. P.; Machens, Hans-Günther; Schilling, Arndt F.
Hydrogels are commonly used biomaterials for tissue engineering. With their high-water content, good biocompatibility and biodegradability they resemble the natural extracellular environment and have been widely used as scaffolds for 3D cell culture and studies of cell biology. The possible size of such hydrogel constructs with embedded cells is limited by the cellular demand for oxygen and nutrients. For the fabrication of large and complex tissue constructs, vascular structures become necessary within the hydrogels to supply the encapsulated cells. In this review, we discuss the types of hydrogels that are currently used for the fabrication of constructs with embedded vascular networks, the key properties of hydrogels needed for this purpose and current techniques to engineer perfusable vascular structures into these hydrogels. We then discuss directions for future research aimed at engineering of vascularized tissue for implantation. PMID:26184185
Liu, Juan; Zheng, Huaiyuan; Poh, Patrina S P; Machens, Hans-Günther; Schilling, Arndt F
Hydrogels are commonly used biomaterials for tissue engineering. With their high-water content, good biocompatibility and biodegradability they resemble the natural extracellular environment and have been widely used as scaffolds for 3D cell culture and studies of cell biology. The possible size of such hydrogel constructs with embedded cells is limited by the cellular demand for oxygen and nutrients. For the fabrication of large and complex tissue constructs, vascular structures become necessary within the hydrogels to supply the encapsulated cells. In this review, we discuss the types of hydrogels that are currently used for the fabrication of constructs with embedded vascular networks, the key properties of hydrogels needed for this purpose and current techniques to engineer perfusable vascular structures into these hydrogels. We then discuss directions for future research aimed at engineering of vascularized tissue for implantation.
Ibrahim, Muhammad; Richardson, Michael K
A major limitation to culturing tissues and organs is the lack of a functional vascular network in vitro. The zebrafish possess many useful properties which makes it a promising model for such studies. Unfortunately, methods of culturing endothelial cells from this species are not well characterised. Here, we tried two methods (embryoid body culture and organ explants from transgenic zebrafish kdrl:GFP embryos) to develop in vitro vascular networks. In the kdrl:GFP line, endothelial cells expresses green fluorescent protein, which allows to track the vascular development in live cultures. We found that embryoid bodies showed significantly longer and wider branches of connected endothelial cells when grown in a microfluidic system than in static culture. Similarly, sprouting of kdrl:GFP(+) cells from the tissue explants was observed in a 3D hydrogel matrix. This study is a step towards the development of zebrafish vascular networks in vitro.
Gold, G; Kövari, E
Vascular dementia due to multiple large strokes (multi-infarct dementia) is a well known entity. However, new clinicopathologic and neuroimaging data have highlighted the common occurrence of small vessel and microscopic vascular pathology in aging brains and recognized that vascular dementia due to small lesions is probably the most common form. In such cases, cortical microinfarcts are the strongest correlate of global cognitive function followed by basal ganglia and thalamic lacunes. Demyelination is only weekly associated with cognition and this relation is no longer significant after adjustement for the presence of lacunes. Awareness of the importance of small vascular lesions in brain aging, can improve diagnostic accuracy and help identify new targets, that could lead to novel therapeutic approaches in old age dementia.
Tresley, Jonathan; Bhatia, Shivank; Kably, Issam; Poozhikunnath Mohan, Prasoon; Salsamendi, Jason; Narayanan, Govindarajan
The Amplatzer Vascular Plug (AVP) is a cylindrical plug made of self-expanding nitinol wire mesh with precise delivery control, which can be used for a variety of vascular pathologies. An AVP is an ideal vascular occlusion device particularly in high-flow vessels, where there is high risk of migration and systemic embolization with traditional occlusion devices. We performed 28 embolizations using the AVP from 2009 to 2014 and achieved complete occlusion without complications. PMID:27413276
Harkin, D W; Beard, J D; Shearman, C P; Wyatt, M G
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.
Kao, Race L.; Tsao-Wu, George; Magovern, George J.
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.
AWARD NUMBER: W81XWH-14-1-0112 TITLE: Hemorrhage Control for Major Traumatic Vascular Injuries PRINCIPAL INVESTIGATOR: John B. Holcomb, M.D...shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number...TITLE AND SUBTITLE Hemorrhage Control for Major Traumatic Vascular Injuries 5a. CONTRACT NUMBER W81XWH-14-1-0112 5b. GRANT NUMBER 5c. PROGRAM
Schwartz, R S; van der Giessen, W J; Holmes, D R
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.
Kang, Hyun-Seung; Wang, Kyu-Chang
Various approaches have been attempted in translational moyamoya disease research. One promising material for modeling and treating this disease is vascular progenitor cells, which can be acquired and expanded from patient peripheral blood. These cells may provide a novel experimental model and enable us to obtain insights regarding moyamoya disease pathogenesis. We briefly present the recent accomplishments in regard to the studies of vascular progenitor cells in moyamoya disease. PMID:26180610
Okada, Yosuke; Mori, Hiroko; Tanaka, Yoshiya; Hashimoto, Osamu
High-frequency severe atherosclerosis/calcinosis is observed in aging, diabetes mellitus and chronic dialysis, which leads to cardiovascular events. Recent progress in basic research has revealed certain similarities between processes of bone calcification and calcifications of vascular tissues which contribute to several cardiovascular diseases. These findings extend the link between bone remodeling and vascular calcification, opening perspectives toward novel therapeutic strategies, however, current evidence is not conclusive and further research is necessary to confirm these actions in the clinical setting.
Dronov, O I; Zemskov, S V; Bakunets, P P
Basing on analysis of own material (84 patients) and data of literature there was established, that vascular invasion by pancreatic tumors constitutes the main obstacle for conduction of the patients' radical treatment. Early diagnosis permits radical resectability of the patients, what constitutes the only one effective method of treatment. In vascular invasion by tumor a surgeon experience and professional preparation determines possibility of the extended operation performance with intervention on affected main vessel, enhancing the treatment radicalism.
Ştefănescu, A; Sas, T; Bătăiosu, C
Clinical study on a group of 48 patients over 3 months: 27 patients were recruited from ophtalmology and 21 recruited from cardiology, 25 % of these patients coming for routine check. Patients were investigated by ophthalmic, cardiologic examination, imaging and laboratory tests. The study demonstrated the need for interdisciplinary consultation for patients with vascular complaints in carotid territory and a close correlation between the vascular pathology and ophthalmology at this level.
hypothesis is that minimally invasive, device-driven and expert-led NCTH control techniques improve survival compared to traditional open vascular surgery...observational study to test the hypothesis that less-invasive device-driven and expert-led hemorrhage control techniques are associated with...invasive, device- driven and expert-led NCTH control techniques improve survival compared to traditional open vascular surgery. In addition to UTHealth
MacRae, Jennifer M; Oliver, Matthew; Clark, Edward; Dipchand, Christine; Hiremath, Swapnil; Kappel, Joanne; Kiaii, Mercedeh; Lok, Charmaine; Luscombe, Rick; Miller, Lisa M; Moist, Louise
When making decisions regarding vascular access creation, the clinician and vascular access team must evaluate each patient individually with consideration of life expectancy, timelines for dialysis start, risks and benefits of access creation, referral wait times, as well as the risk for access complications. The role of the multidisciplinary team in facilitating access choice is reviewed, as well as the clinical evaluation of the patient.
MacRae, Jennifer M.; Oliver, Matthew; Clark, Edward; Dipchand, Christine; Hiremath, Swapnil; Kappel, Joanne; Kiaii, Mercedeh; Lok, Charmaine; Luscombe, Rick; Miller, Lisa M.; Moist, Louise
When making decisions regarding vascular access creation, the clinician and vascular access team must evaluate each patient individually with consideration of life expectancy, timelines for dialysis start, risks and benefits of access creation, referral wait times, as well as the risk for access complications. The role of the multidisciplinary team in facilitating access choice is reviewed, as well as the clinical evaluation of the patient. PMID:28270917
Pongratz, J; Reeps, C; Eckstein, H-H
Arterial and venous vascular injuries are known but rare complications of severe multiple traumatised patients but are meanwhile more frequently induced iatrogenically. However there are only few reports about incidence, causes, surgical techniques and prognosis of these vascular emergencies. We have therefore analysed the causes, type of therapy, localisation of injury, primary dis-ease, morbidity and mortality of all vascular emergencies in patients without preexisting vascular disease. 2.9 % of all vascular repairs in our unit had to be performed for cases of iatrogenic (87 %) and non-iatrogenic (13 %) vascular complications. The overall mortality and major complication rate of these intrahospital iatrogenically aquired lesions were 4.8 % and 5 %, respectively, which are clearly below those of extrahospital vascular injuries. Thereby the observed increase of iatrogenic vascular injuries seems to be due to the increase in complex and even catheter-based techniques in modern therapy. The iliacofemoral region was affected in 45 % of the cases, in 50 % complex reconstructions and specific surgical skills were needed for the repair. This article on the incidence of and reasons for vascular iatrogenic lesions shows the importance of a planned management for the prognosis of these injuries.
Kalaria, Raj N.; Akinyemi, Rufus; Ihara, Masafumi
The global burden of ischaemic strokes is almost 4-fold greater than haemorrhagic strokes. Current evidence suggests that 25–30% of ischaemic stroke survivors develop immediate or delayed vascular cognitive impairment (VCI) or vascular dementia (VaD). Dementia after stroke injury may encompass all types of cognitive disorders. States of cognitive dysfunction before the index stroke are described under the umbrella of pre-stroke dementia, which may entail vascular changes as well as insidious neurodegenerative processes. Risk factors for cognitive impairment and dementia after stroke are multifactorial including older age, family history, genetic variants, low educational status, vascular comorbidities, prior transient ischaemic attack or recurrent stroke and depressive illness. Neuroimaging determinants of dementia after stroke comprise silent brain infarcts, white matter changes, lacunar infarcts and medial temporal lobe atrophy. Until recently, the neuropathology of dementia after stroke was poorly defined. Most of post-stroke dementia is consistent with VaD involving multiple substrates. Microinfarction, microvascular changes related to blood–brain barrier damage, focal neuronal atrophy and low burden of co-existing neurodegenerative pathology appear key substrates of dementia after stroke injury. The elucidation of mechanisms of dementia after stroke injury will enable establishment of effective strategy for symptomatic relief and prevention. Controlling vascular disease risk factors is essential to reduce the burden of cognitive dysfunction after stroke. This article is part of a Special Issue entitled: Vascular Contributions to Cognitive Impairment and Dementia edited by M. Paul Murphy, Roderick A. Corriveau and Donna M. Wilcock. PMID:26806700
Knopman, David S.; Roberts, Rosebud
Cerebrovascular disease plays an important role in cognitive disorders in the elderly. Cerebrovascular disease and Alzheimer’s disease interact on several levels, one important level being the overlap in risk factors. The major vascular risk factors such as diabetes and impaired glycemic control, hypertension, obesity and hyper- or dyslipidemia have been associated both with Alzheimer’s disease and vascular dementia. The purpose of this review is to consider the context in which vascular dementia is diagnosed, place the pathophysiological consequences of cerebrovascular disease on cognition in the context of clinical and pathological Alzheimer’s disease, and then to consider the evidence for the role of major vascular risk factors in late-life cognitive impairment, changes in brain imaging and neuropathological changes. Midlife diabetes mellitus, hypertension and obesity are established risk factors for clinically defined Alzheimer’s disease as well as vascular dementia. The basis for these relationships could either be that the risk factors lead to microvascular brain disease, promote Alzheimer pathology or both. The associations of late-life onset diabetes mellitus, hypertension and obesity with cognitive impairment are either attenuated or reversed. The role of vascular risk factors in midlife should be the focus of public health efforts to reduce the burden of late-life cognitive impairment. PMID:20182020
Imaging of patients with vascular tumors and malformations has been sufficiently refined to answer pertinent questions when making treatment decisions in this challenging subgroup of pediatric patients. The imaging modalities at hand include conventional radiography, Doppler ultrasound, and magnetic resonance imaging with time-resolved, contrast-material enhanced magnetic resonance angiography. This review article will focus on the characteristic imaging features of some focal and diffuse vascular lesions, which have been classified by their clinical history and physical exam, and further labeled as a vascular tumor or slow-flow versus high-flow vascular malformation based on the updated classification system proposed by the International Society for the Study of Vascular Anomalies. The recent advances in knowledge regarding the biology of these vascular anomalies have led to increased awareness of the current nomenclature. Moreover, with better understanding of the imaging features, the radiologist has become a key player in the multidisciplinary approach offered at various institutions where appropriate treatment algorithms and interventional strategies are put together. This is crucial in avoiding misdiagnosis and improper management. PMID:25045332
Acute vascular emergencies can arise from direct traumatic injury to the vessel or be spontaneous (non-traumatic). The vascular injuries can also be divided into two categories: arteial injury and venous injury. Most of them are life-treatening emergencies, sice they may cause an important ipovolemic shock or severe ischemia in their end organ and require prompt diagnosis and treatment. In the different clinical scenarios, the correct diagnostic approach to vascular injuries isn’t firmly established and advantages of one imaging technique over the other are not obvious. Ultrasound (US) is an easy accessible, safe and non-invasive diagnostic modality but Computed Tomography (CT) with multiphasic imaging study is an accurate modality to evaluate the abdominal vascular injuries therefore can be considered the primary imaging modality in vascular emergencies. The aim of this review article is to illustrate the different imaging options for the diagnosis of abdominal vascular emergencies, including traumatic and non traumatic vessel injuries, focusing of US and CT modalities. PMID:23902665
Genovese, Eugenio Annibale; Fonio, Paolo; Floridi, Chiara; Macchi, Monica; Maccaferri, Anna; Ianora, Antonio Amato Stabile; Cagini, Lucio; Carrafiello, Gianpaolo
Acute vascular emergencies can arise from direct traumatic injury to the vessel or be spontaneous (non-traumatic).The vascular injuries can also be divided into two categories: arteial injury and venous injury.Most of them are life-treatening emergencies, sice they may cause an important ipovolemic shock or severe ischemia in their end organ and require prompt diagnosis and treatment.In the different clinical scenarios, the correct diagnostic approach to vascular injuries isn't firmly established and advantages of one imaging technique over the other are not obvious.Ultrasound (US) is an easy accessible, safe and non-invasive diagnostic modality but Computed Tomography (CT) with multiphasic imaging study is an accurate modality to evaluate the abdominal vascular injuries therefore can be considered the primary imaging modality in vascular emergencies.The aim of this review article is to illustrate the different imaging options for the diagnosis of abdominal vascular emergencies, including traumatic and non traumatic vessel injuries, focusing of US and CT modalities.
The control of force production in vascular smooth muscle is critical to the normal regulation of blood flow and pressure, and altered regulation is common to diseases such as hypertension, heart failure, and ischemia. A great deal has been learned about imbalances in vasoconstrictor and vasodilator signals, e.g., angiotensin, endothelin, norepinephrine, and nitric oxide, that regulate vascular tone in normal and disease contexts. In contrast there has been limited study of how the phenotypic state of the vascular smooth muscle cell may influence the contractile response to these signaling pathways dependent upon the developmental, tissue-specific (vascular bed) or disease context. Smooth, skeletal, and cardiac muscle lineages are traditionally classified into fast or slow sublineages based on rates of contraction and relaxation, recognizing that this simple dichotomy vastly underrepresents muscle phenotypic diversity. A great deal has been learned about developmental specification of the striated muscle sublineages and their phenotypic interconversions in the mature animal under the control of mechanical load, neural input, and hormones. In contrast there has been relatively limited study of smooth muscle contractile phenotypic diversity. This is surprising given the number of diseases in which smooth muscle contractile dysfunction plays a key role. This review focuses on smooth muscle contractile phenotypic diversity in the vascular system, how it is generated, and how it may determine vascular function in developmental and disease contexts. PMID:20736412
Hoerstrup, S P; Zünd, G; Sodian, R; Schnell, A M; Grünenfelder, J; Turina, M I
Previous tissue engineering approaches to create small caliber vascular grafts have been limited by the structural and mechanical immaturity of the constructs. This study uses a novel in vitro pulse duplicator system providing a 'biomimetic' environment during tissue formation to yield more mature, implantable vascular grafts. Vascular grafts (I.D. 0.5 cm) were fabricated from novel bioabsorbable polymers (polyglycolic-acid/poly-4-hydroxybutyrate) and sequentially seeded with ovine vascular myofibroblasts and endothelial cells. After 4 days static culture, the grafts (n=24) were grown in vitro in a pulse duplicator system (bioreactor) for 4, 7, 14, 21, and 28 days. Controls (n=24) were grown in static culture conditions. Analysis of the neo-tissue included histology, scanning electron microscopy (SEM), and biochemical assays (DNA for cell content, 5-hydroxyproline for collagen). Mechanical testing was performed measuring the burst pressure and the suture retention strength. Histology showed viable, dense tissue in all samples. SEM demonstrated confluent smooth inner surfaces of the grafts exposed to pulsatile flow after 14 days. Biochemical analysis revealed a continuous increase of cell mass and collagen to 21 days compared to significantly lower values in the static controls. The mechanical properties of the pulsed vascular grafts comprised supra-physiological burst strength and suture retention strength appropriate for surgical implantation. This study demonstrates the feasibility of tissue engineering of viable, surgically implantable small caliber vascular grafts and the important effect of a 'biomimetic' in vitro environment on tissue maturation and extracellular matrix formation.
Ferro, Carlo; Rossi, Umberto G. Bovio, Giulio; Petrocelli, Francesco; Seitun, Sara
The purpose of this communication is to describe our preliminary experience with the AMPLATZER Vascular Plug 4 (AVP 4) in peripheral vascular embolization. The AVP 4 was used for peripheral vascular embolization in five patients with renal pseudoaneurysm (n = 2), postsurgical peritoneal bleeding (n = 1), posttraumatic gluteal hemorrhage (n = 1), and intercostal pseudoaneurysm (n = 1). Occlusion time was recorded. Patients were followed up clinically and by imaging for 1 month after the procedure. All treated vessels or vascular abnormalities were successfully occluded within 3 min for low-flow circulation and over 8 min for high-flow circulation. At 1-month follow-up, all patients were symptom-free. All deployed devices remained in the original locations and desirable configurations. In conclusion, the AVP 4 seems to be safe and effective for occluding peripheral vessels and vascular abnormalities. Because of its compatibility with 0.038-in. catheters, it can be deployed through a diagnostic catheter following angiography without exchanging a sheath or guiding catheter. Compared with the previous generation of vascular plugs, the AVP 4 allows for faster procedure times and decreased exposure to radiation.
Chiu, Yu-Chieh; Cheng, Ming-Huei; Uriel, Shiri; Brey, Eric M
Loss of adipose tissue can occur due to congenital and acquired lipoatrophies, trauma, tumor resection, and chronic disease. Clinically, it is difficult to regenerate or reconstruct adipose tissue. The extensive microvsacular network present in adipose, and the sensitivity of adipocytes to hypoxia, hinder the success of typical tissue transfer procedures. Materials that promote the formation of vascularized adipose tissue may offer alternatives to current clinical treatment options. A number of synthetic and natural biomaterials common in tissue engineering have been investigated as scaffolds for adipose regeneration. While these materials have shown some promise they do not account for the unique extracellular microenvironment of adipose. Adipose derived hydrogels more closely approximate the physical and chemical microenvironment of adipose tissue, promote preadipocyte differentiation and vessel assembly in vitro, and stimulate vascularized adipose formation in vivo. The combination of these materials with techniques that promote rapid and stable vascularization could lead to new techniques for engineering stable, vascularized adipose tissue for clinical application. In this review we discuss materials used for adipose tissue engineering and strategies for vascularization of these scaffolds. Materials that promote formation of vascularized adipose tissue have the potential to serve as alternatives or supplements to existing treatment options, for adipose defects or deficiencies resulting from chronic disease, lipoatrophies, trauma, and tumor resection. Copyright © 2009 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.
Humphrey, Shannon; Carruthers, Jean D.A.; Carruthers, Alastair
The popularity of soft tissue fillers is, in part, due to their favorable side-effect profile. However, serious complications can occur. The authors describe their extensive clinical experience with soft-tissue augmentation and the rare complication of vascular compromise, which can lead to necrosis and scarring. Over a 10-year period between January 2003 and January 2013, the authors observed a total of 12 cases of vascular compromise. Eight patients in their clinical practice showed evidence of vascular compromise out of a total of 14,355 filler injections (0.05%). In addition, four patients treated with an experimental particulate filler had vascular complications. All cases were examined for filler type, location of complication, risk factors, treatment, and outcomes. Although treatment plans differed for each patient in their series, all cases of vascular compromise resolved fully. The authors believe that an office-based protocol for both immediate and ongoing care—including a thorough individualized assessment and treatment plan for each patient—is critical to timely and effective resolution of side effects. They propose key recommendations for the prevention and management of vascular compromise to improve patient outcomes and reduce the risk of permanent complications. PMID:25276276
Im, Seung Hyuk; Jung, Youngmee; Kim, Soo Hyun
Because of the increasing incidence of coronary artery disease, the importance of cardiovascular stents has continuously increased as a treatment of this disease. Biodegradable scaffolds fabricated from polymers and metals have emerged as promising materials for vascular stents because of their biodegradability. Although such stent framework materials have shown good clinical efficacy, it is difficult to decide whether polymers or metals are better vascular scaffolds because their properties are different. Therefore, there are still obstacles in the development of biodegradable vascular scaffolds in terms of improving clinical efficacy. This review analyzes the pros and cons of current stent materials with respect to five key factors for next-generation stent and discusses methods of improvement. Furthermore, we discuss biodegradable electronic stents with electrical conductivity, which has been considered unimportant until now, and highlight electrical conductivity as a key factor in the development of next-generation stents. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Kim, Bradford J; Valsangkar, Nakul P; Liang, Tiffany W; Murphy, Michael P; Zimmers, Teresa A; Bell, Teresa M; Davies, Mark G; Koniaris, Leonidas G
Changing training paradigms in vascular surgery have been introduced to reduce overall training time. Herein, we sought to examine how shortened training for vascular surgeons may have influenced overall divisional academic productivity. Faculty from the top 55 surgery departments were identified according to National Institutes of Health (NIH) funding. Academic metrics of 315 vascular surgery, 1,132 general surgery, and 2,403 other surgical specialties faculty were examined using institutional Web sites, Scopus, and NIH Research Portfolio Online Reporting Tools from September 1, 2014, to January 31, 2015. Individual-level and aggregate numbers of publications, citations, and NIH funding were determined. The mean size of the vascular divisions was 5 faculty. There was no correlation between department size and academic productivity of individual faculty members (R(2) = 0.68, P = 0.2). Overall percentage of vascular surgery faculty with current or former NIH funding was 20%, of which 10.8% had major NIH grants (R01/U01/P01). Vascular surgery faculty associated with integrated vascular training programs demonstrated significantly greater academic productivity. Publications and citations were higher for vascular surgery faculty from institutions with both integrated and traditional training programs (48 of 1,051) compared to those from programs with integrated training alone (37 of 485) or traditional fellowships alone (26 of 439; P < 0.05). In this retrospective examination, academic productivity was improved within vascular surgery divisions with integrated training programs or both program types. These data suggest that the earlier specialization of integrated residencies in addition to increasing dedicated vascular training time may actually help promote research within the field of vascular surgery. Copyright © 2016 Elsevier Inc. All rights reserved.
Wang, Meili; Fu, Yi; Gao, Cheng; Jia, Yiting; Huang, Yaqian; Liu, Limei; Wang, Xian; Wang, Wengong; Kong, Wei
Aging-related vascular dysfunction contributes to cardiovascular morbidity and mortality. Cartilage oligomeric matrix protein (COMP), a vascular extracellular matrix protein, has been described as a negative regulatory factor for the vascular aging-related processes including atherosclerosis and vascular calcification. However, whether COMP is implicated in the process of vascular aging remains unclear. Here, we identified a novel function of COMP in preventing vascular aging and vascular smooth muscle cells (VSMCs) senescence. Firstly, vascular COMP expression was decreased in three different senescence-accelerated mouse models and was also declining with age. COMP(-/-) mice displayed elevated senescence-associated markers expression, including p53, p21 and p16, in the aortas compared with their wild type (WT) littermates. In accordance, COMP deficiency induced aging-related vascular dysfunction as evidenced by the significantly reduced phenylephrine-induced contraction and increased vascular stiffness as evaluated by pulse wave velocity. The aortic wall of COMP(-/-) mice was susceptible to senescence by displaying senescence-associated β-galactosidase (SA β-gal) activity induced by periadventitial application of CaCl2 to the abdominal aorta. In vitro, COMP knockdown by small interfering (si) RNA led to the elevation of p53, p21 and p16 as well as SA β-gal activity in VSMCs after H2O2 stimulation. VSMCs isolated from COMP(-/-) mice showed elevated senescence-associated markers expression and supplement of COMP adenovirus to COMP-deficient VSMCs greatly rescued cellular senescence. Taken together, these findings revealed the essential role of COMP in retarding the development of vascular aging and VSMC senescence. Copyright © 2016 Elsevier Inc. All rights reserved.
Background Tocopherols have biphasic, proangiogenic and antiangiogenic therapeutic effects. The objective of this clinical trial was to clarify tocopherol's placental angiogenic potential in late pregnant ewes following oral supplementation. Methods Eighteen pregnant ewes during late gestation were selected for this study. Ewes were given oral supplementation of 500 mg of alpha-tocopherol (aT; N = 6) or 1000 mg of gamma-tocopherol (gT; N = 7) or placebo (CON; N = 5) once daily from 107 to 137 days post breeding. Serum was obtained at weekly intervals and tissue samples were obtained at the end of supplementation to: 1) evaluate tocopherol concentrations in serum, uterus and placentome; 2) evaluate relative mRNA expressions of Vascular Endothelial Growth Factor (VEGF), Placental Growth Factor (PlGF), endothelial Nitric Oxide Synthase (eNOS) and Hypoxia Inducible Factors (HIF) in uterus, caruncle and cotyledon; 3) analyze the morphometry of the placental vascular network. Results Supplementation of aT or gT resulted in increased concentrations in serum, placentome and uterus compared to control (P < 0.05). In aT group, mRNA expressions of PlGF, eNOS and HIF-1α in cotyledon were greater than the CON group. In gT group, mRNA expressions of VEGF, eNOS, HIF-1 alpha and HIF-2 alpha in caruncle and uterus, and HIF-1α in cotyledon, were greater than the CON group. Morphometry analysis revealed increased angiogenesis in the supplemented groups. Conclusion Daily oral supplementation of aT or gT increased angiogenesis in the placental vascular network in pregnant ewes during late gestation. Increase in placental angiogenesis may provide nutrients required for the development and growth of fetus during late pregnancy. PMID:20624307
Baghi, Iraj; Herfatkar, Mohammad Rasool; Shokrgozar, Leila; Poor-Rasuli, Zahra; Aghajani, Fatemeh
Trauma is the third leading cause of death. In this regard, vascular injury plays a leading role in of morbidity and mortality rates. The present study aimed to assess the prevalence of vascular injuries and results of vascular reconstruction at a referral hospital in northern Iran. A retrospective observational study assessed 88 consecutive patients with vascular injury admitted to Poursina Hospital, Rasht in northern Iran, from October 2007 to October 2009. All study information was collected retrospectively from hospital charts. Most of the affected patients (87/88) were male with a mean age of 29.12 ± 11.20 years. The mechanism of injury in 39.8% was blunt trauma and penetrating trauma in the rest. Of the 53 injured by penetrating trauma (60.2%), the most common cause was stabbing (94.3%). The most common cause of blunt trauma was road traffic accidents (93.1%). The most common mechanism for vascular injuries in upper extremities was penetrating trauma (86.0%) and in lower extremities was blunt trauma (60.0%). Fasciotomy was performed in 16 patients (18.2%) mostly in the lower extremities. Major amputation was required in 10% of the patients. In upper extremities, the most common type of revascularization was end to end anastomosis, followed by inter-position graft. The most common type of reconstruction in the lower extremity was bypass graft. All patients who underwent major amputation were admitted to the center with a delay of more than 6 hours after injury. Major vascular injuries in our center occurred in young men, frequently because of stab wounds. Popliteal injuries mostly caused by motor vehicle accidents was the second most common arterial injury, followed by combined ulnar and radial injuries. Vascular reconstruction in the first hours after trauma may prevent many unnecessary and preventable amputation procedures.
Khan, Mohammad Iqbal; Khan, Najam; Abbasi, Shafquat Ali; Baqai, Mohammad Tariq; ur Rehman, Bashir; Wayne, Abdul
Vascular trauma is a common life threatening injury leading to serious consequences if not timely and efficiently managed. We evaluated early surgical interventions aimed at revascularization and thus salvaging limb/organ in life threatening vascular injuries. Aims of our study were to evaluate the outcome of available diagnostic modalities, earliest possible surgical intervention and rate of related complications with particular reference to our existing situation. Emergency diagnostic workup based mainly on clinical evaluations and required laboratory and imaging parameters leading to revascularisation was performed in 48 patients in Combined Military Hospital (CMH) Muzaffarabad and Islamic Medical College Hospitals between June 1997 and December 2001. Data was collected on pre-designed computerized proforma's which were completed by the treating surgeon and data was entered and analyzed accordingly. Out of the total 48 patients who sustained major vascular injuries during this period, 14 (29.2%) were having injury to upper limb vessels, 26 (54.2%) patients had injury to the lower limb vessels, 6 (12.5%) patients reported with injury to abdominal vessels. One (2%) patient had injury to common carotid artery, while an other patient to thoracic aorta respectively (2%). Penetrating trauma caused 38 (79%) and blunt trauma caused 10 (21%) major vascular injuries. Out of 48 patients, 41 (85.4%) patients were successful managed by vascular reconstruction without any residual disability. Speedy diagnostic work up and early revascularization yields favourable outcome in vast majority of patients requiring vascular repair. Selections of surgical technique including use of autologous vein graft or artificial vascular graft can save many limbs. In order to achieve good results the time lapse between injury and revascularisation should be less than 6 hours.
Glebova, Natalia O; Bronsert, Michael; Hammermeister, Karl E; Nehler, Mark R; Gibula, Douglas R; Malas, Mahmoud B; Black, James H; Henderson, William G
Postoperative readmissions are frequent in vascular surgery patients, but it is not clear which factors are the main drivers of readmissions. Specifically, the relative contributions of patient comorbidities vs those of operative factors and postoperative complications are unknown. We sought to study the multiple potential drivers of readmission and to create a model for predicting the risk of readmission in vascular patients. The 2012-2013 American College of Surgeons National Surgical Quality Improvement Program data set was queried for unplanned readmissions in 86,238 vascular patients. Multivariable forward selection logistic regression analysis was used to model the relative contributions of patient comorbidities, operative factors, and postoperative complications for readmission. The unplanned readmission rate was 9.3%. The preoperative model based on patient demographics and comorbidities predicted readmission risk with a low C index of .67; the top five predictors of readmission were American Society of Anesthesiologists class, preoperative open wound, inpatient operation, dialysis dependence, and diabetes mellitus. The postoperative model using operative factors and postoperative complications predicted readmission risk better (C index, .78); postoperative complications were the most significant predictor of readmission, overpowering patient comorbidities. Importantly, postoperative complications identified before discharge from the hospital were not a strong predictor of readmission as the model using predischarge postoperative complications had a similar C index to our preoperative model (.68). However, the inclusion of complications identified after discharge from the hospital appreciably improved the predictive power of the model (C index, .78). The top five predictors of readmission in the final model based on patient comorbidities and postoperative complications were postdischarge deep space infection, superficial surgical site infection, pneumonia
Steppan, Jochen; Sikka, Gautam; Jandu, Simran; Barodka, Viachaslau; Halushka, Marc K.; Flavahan, Nicholas A.; Belkin, Alexey M.; Nyhan, Daniel; Butlin, Mark; Avolio, Alberto; Berkowitz, Dan E.; Santhanam, Lakshmi
Background Vascular aging is closely associated with increased vascular stiffness. It has recently been demonstrated that decreased nitric oxide (NO)‐induced S‐nitrosylation of tissue transglutaminase (TG2) contributes to age‐related vascular stiffness. In the current study, we tested the hypothesis that exercise restores NO signaling and attenuates vascular stiffness by decreasing TG2 activity and cross‐linking in an aging rat model. Methods and Results Rats were subjected to 12 weeks of moderate aerobic exercise. Aging was associated with diminished phosphorylated endothelial nitric oxide synthase and phosphorylated vasodilator‐stimulated phosphoprotein abundance, suggesting reduced NO signaling. TG2 cross‐linking activity was significantly increased in old animals, whereas TG2 abundance remained unchanged. These alterations were attenuated in the exercise cohort. Simultaneous measurement of blood pressure and pulse wave velocity (PWV) demonstrated increased aortic stiffness in old rats, compared to young, at all values of mean arterial pressure (MAP). The PWV‐MAP correlation in the old sedentary and old exercise cohorts was similar. Tensile testing of the vessels showed increased stiffness of the aorta in the old phenotype with a modest restoration of mechanical properties toward the young phenotype with exercise. Conclusions Increased vascular stiffness during aging is associated with decreased TG2 S‐nitrosylation, increased TG2 cross‐linking activity, and increased vascular stiffness likely the result of decreased NO bioavailability. In this study, a brief period of moderate aerobic exercise enhanced NO signaling, attenuated TG cross‐linking activity, and reduced ex vivo tensile properties, but failed to reverse functional vascular stiffness in vivo, as measured by PWV. PMID:24721796
Kida, Yujiro; Goligorsky, Michael S
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.
Richter, Gresham T.; Friedman, Adva B.
Vascular anomalies are a heterogeneous group of congenital blood vessel disorders more typically referred to as birthmarks. Subcategorized into vascular tumors and malformations, each anomaly is characterized by specific morphology, pathophysiology, clinical behavior, and management approach. Hemangiomas are the most common vascular tumor. Lymphatic, capillary, venous, and arteriovenous malformations make up the majority of vascular malformations. This paper reviews current theory and practice in the etiology, diagnosis, and treatment of these more common vascular anomalies. PMID:22611412
Jee, Haemi; Park, Jaehyun; Oh, Jae-Gun; Lee, Yoon-Hee; Shin, Kyung-A; Kim, Young-Joo
The aim of this study was to observe the changes in endothelial and inflammatory markers in middle-aged male runners with exercise-induced hypertension (EIH) at baseline and at 100-km, 200-km, and 308-km checkpoints during a prolonged endurance ultramarathon. Among a total of 62 ultramarathon volunteers, 8 with systolic blood pressure higher than 210 mm Hg and 8 with normal systolic blood pressure were selected for this study. The subjects were designated to EIH and control (CON) groups. Blood was collected for the analysis of soluble vascular cell adhesion molecule-1, soluble E-selectin, leukocytes, creatine kinase, and high-sensitivity C-reactive protein. Soluble vascular cell adhesion molecule-1 showed a significantly greater increase in the EIH group than in the CON group at 100 km and 200 km. Soluble E-selectin also showed a significantly greater increase in the EIH group than in the CON group at 100 km. Leukocytes significantly increased in the EIH group than in the CON group at 308 km. Creatine kinase and high-sensitivity C-reactive protein showed no group differences. Leukocytes, creatine kinase, and high-sensitivity C-reactive protein showed delayed-onset increases in both groups. Increased exercise intensity may stimulate greater endothelial responses independent of the inflammatory markers in EIH. The loss of a protective effect may be greater in those with EIH than in CONs. Acknowledging and prescribing proper exercise intensity may be critical in preventing possible vascular-related complications in runners with EIH.
Vascular graft is a widely-used medical device for the treatment of vascular diseases such as atherosclerosis and aneurysm as well as for the use of vascular access and pediatric shunt, which are major causes of mortality and morbidity in this world. Dysfunction of vascular grafts often occurs, particularly for grafts with diameter less than 6mm, and is associated with the design of graft materials. Mechanical strength, compliance, permeability, endothelialization and availability are issues of most concern for vascular graft materials. To address these issues, we have designed a biodegradable, compliant graft made of hybrid multilayer by combining an intimal equivalent, electrospun heparin-impregnated poly-epsilon-caprolactone nanofibers, with a medial equivalent, a crosslinked collagen-chitosan-based gel scaffold. The intimal equivalent is designed to build mechanical strength and stability suitable for in vivo grafting and to prevent thrombosis. The medial equivalent is designed to serve as a scaffold for the activity of the smooth muscle cells important for vascular healing and regeneration. Our results have shown that genipin is a biocompatible crosslinker to enhance the mechanical properties of collagen-chitosan based scaffolds, and the degradation time and the activity of smooth muscle cells in the scaffold can be modulated by the crosslinking degree. For vascular grafting and regeneration in vivo, an important design parameter of the hybrid multilayer is the interface adhesion between the intimal and medial equivalents. With diametrically opposite affinities to water, delamination of the two layers occurs. Physical or chemical modification techniques were thus used to enhance the adhesion. Microscopic examination and graft-relevant functional characterizations have been performed to evaluate these techniques. Results from characterization of microstructure and functional properties, including burst strength, compliance, water permeability and suture
Sevostyanova, V. V. Khodyrevskaya, Y. I.; Glushkova, T. V.; Antonova, L. V.; Kudryavtseva, Y. A.; Barbarash, O. L.; Barbarash, L. S.
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.
Many of the cardiovascular parameters or incidences of coronary artery diseases display circadian variations. These day/night time variances may be attributable to the diurnal change in vascular contractility. However, the molecular mechanism of the vascular clock system which generates the circadian variation of vascular contractility has remained largely unknown. Recently we found the existence of the intrinsic circadian rhythm in vascular contractility. A clock gene Rorα in vascular smooth muscle cells (VSMC) provokes the diurnal oscillatory change in the expression of Rho-associated kinase 2 (ROCK2), which induces the time-of-day-dependent variation in the agonist-induced phosphorylation of myosin light chain (MLC) and myofilament Ca(2+) sensitization. In this review, we introduce our recent findings with reference to the molecular basis of the biological clock system and the current literature concerning cardiovascular chronobiology.
Many of the cardiovascular parameters or incidences of coronary artery diseases display circadian variations. These day/night time variances may be attributable to the diurnal change in vascular contractility. However, the molecular mechanism of the vascular clock system which generates the circadian variation of vascular contractility has remained largely unknown. Recently we found the existence of the intrinsic circadian rhythm in vascular contractility. A clock gene Rorα in vascular smooth muscle cells (VSMC) provokes the diurnal oscillatory change in the expression of Rho-associated kinase 2 (ROCK2), which induces the time-of-day-dependent variation in the agonist-induced phosphorylation of myosin light chain (MLC) and myofilament Ca2+ sensitization. In this review, we introduce our recent findings with reference to the molecular basis of the biological clock system and the current literature concerning cardiovascular chronobiology. PMID:26935878
Sevostyanova, V. V.; Khodyrevskaya, Y. I.; Glushkova, T. V.; Antonova, L. V.; Kudryavtseva, Y. A.; Barbarash, O. L.; Barbarash, L. S.
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.
Rich, N M
The 25th Annual (Silver Anniversary) Vascular Surgery Seminar and Meeting of the Society for Military Vascular Surgery was held in the Jay P. Sanford Auditorium at the F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences (USUHS), 4-6 December 1997. This highly successful exchange included active duty military surgeons, military surgeons in the reserves, retired military officers continuing second careers in civilian vascular surgery, distinguished visiting professors from the United States and abroad, International Guest Scholars, USUHS Faculty as well as colleagues and friends. The emphasis continued to be directed to ensuring that military vascular surgery remains current, recognizing the rich heritage of contributions to vascular surgery in general that have come from surgeons serving on battlefields around the world, particularly in this 20th century.
Liu, Yue; Chen, Ke-Ji
With the arrival of the era of global population aging, we strive for healthy aging and a healthy senior life rather than simple prolongation of the physical age. For the past 50 years, cardiovascular diseases (CVD) have been the most common cause of death among the elderly people globally. In China, there has been an exponential increase in the incidence of heart disease and stroke in the elderly population. Atherosclerosis is the pathological change in the coronary artery disease, stroke, and peripheral vascular disease. Despite the significant benefit demonstrated, control of classic risk factors alone, such as lifestyle change or drug therapy, was shown to have limitations in reducing the incidence of cardiovascular events. Vascular aging has been shown to be an important independent predictor of CVD events. Interventions targeting vascular aging have emerged as a new paradigm in conjunction with control of risk factors for the prevention of CVD. Vascular aging and atherosclerosis are two distinct pathological changes and difficult to distinguish clinically. Recent research with Chinese medicine (CM) has shown encouraging observations, linking the clinical benefit of delaying vascular aging and treating atherosclerosis. These results demonstrate great potential of CM in the prevention and treatment of CVD.
Horiuchi, Masahiro; Okita, Koichi
It is established that regular aerobic training improves vascular function, for example, endothelium-dependent vasodilatation and arterial stiffness or compliance and thereby constitutes a preventative measure against cardiovascular disease. In contrast, high-intensity resistance training impairs vascular function, while the influence of moderate-intensity resistance training on vascular function is still controversial. However, aerobic training is insufficient to inhibit loss in muscular strength with advancing age; thus, resistance training is recommended to prevent sarcopenia. Recently, several lines of study have provided compelling data showing that exercise and training with blood flow restriction (BFR) leads to muscle hypertrophy and strength increase. As such, BFR training might be a novel means of overcoming the contradiction between aerobic and high-intensity resistance training. Although it is not enough evidence to obtain consensus about impact of BFR training on vascular function, available evidences suggested that BFR training did not change coagulation factors and arterial compliance though with inconsistence results in endothelial function. This paper is a review of the literature on the impact of BFR exercise and training on vascular function, such as endothelial function, arterial compliance, or other potential factors in comparison with those of aerobic and resistance training.
Miyashima, Shunsuke; Sebastian, Jose; Lee, Ji-Young; Helariutta, Yka
The plant vascular system, composed of xylem and phloem, evolved to connect plant organs and transport various molecules between them. During the post-embryonic growth, these conductive tissues constitutively form from cells that are derived from a lateral meristem, commonly called procambium and cambium. Procambium/cambium contains pluripotent stem cells and provides a microenvironment that maintains the stem cell population. Because vascular plants continue to form new tissues and organs throughout their life cycle, the formation and maintenance of stem cells are crucial for plant growth and development. In this decade, there has been considerable progress in understanding the molecular control of the organization and maintenance of stem cells in vascular plants. Noticeable advance has been made in elucidating the role of transcription factors and major plant hormones in stem cell maintenance and vascular tissue differentiation. These studies suggest the shared regulatory mechanisms among various types of plant stem cell pools. In this review, we focus on two aspects of stem cell function in the vascular cambium, cell proliferation and cell differentiation.
Huo, Yunlong; Kassab, Ghassan S
A fundamental physics-based derivation of intraspecific scaling laws of vascular trees has not been previously realized. Here, we provide such a theoretical derivation for the volume-diameter and flow-length scaling laws of intraspecific vascular trees. In conjunction with the minimum energy hypothesis, this formulation also results in diameter-length, flow-diameter and flow-volume scaling laws. The intraspecific scaling predicts the volume-diameter power relation with a theoretical exponent of 3, which is validated by the experimental measurements for the three major coronary arterial trees in swine (where a least-squares fit of these measurements has exponents of 2.96, 3 and 2.98 for the left anterior descending artery, left circumflex artery and right coronary artery trees, respectively). This scaling law as well as others agrees very well with the measured morphometric data of vascular trees in various other organs and species. This study is fundamental to the understanding of morphological and haemodynamic features in a biological vascular tree and has implications for vascular disease.
Miyashima, Shunsuke; Sebastian, Jose; Lee, Ji-Young; Helariutta, Yka
The plant vascular system, composed of xylem and phloem, evolved to connect plant organs and transport various molecules between them. During the post-embryonic growth, these conductive tissues constitutively form from cells that are derived from a lateral meristem, commonly called procambium and cambium. Procambium/cambium contains pluripotent stem cells and provides a microenvironment that maintains the stem cell population. Because vascular plants continue to form new tissues and organs throughout their life cycle, the formation and maintenance of stem cells are crucial for plant growth and development. In this decade, there has been considerable progress in understanding the molecular control of the organization and maintenance of stem cells in vascular plants. Noticeable advance has been made in elucidating the role of transcription factors and major plant hormones in stem cell maintenance and vascular tissue differentiation. These studies suggest the shared regulatory mechanisms among various types of plant stem cell pools. In this review, we focus on two aspects of stem cell function in the vascular cambium, cell proliferation and cell differentiation. PMID:23169537
Gupta, Anirban Sen
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.
Nagata, K; Kondoh, Y; Atchison, R; Sato, M; Satoh, Y; Watahiki, Y; Hirata, Y; Yokoyama, E
Vascular and metabolic reserve were analyzed in probable Alzheimer's disease (AD) and vascular dementia (VaD). Cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral metabolic rate of oxygen (CMRO(2)), and oxygen extraction fraction (OEF) were measured quantitatively with positron emission tomography (PET). Vascular reactivity (VR) was also calculated by comparing the CBF during 5% CO(2) inhalation with the CBF during normal breathing. Vascular transit time (VTT) that was calculated as a ratio of CBV/CBF and VR reflect vasodilating capacity of the small resistance vessels, whereas OEF designates metabolic (oxygen-extraction) reserve in threatening brain ischemia. Significant increase in OEF was seen in the parieto-temporal cortex and both VTT and VR were preserved in AD patients. By constrast, there was no significant increase in OEF whereas VTT was prolonged and VR was markedly depressed in VaD patients. The increase of OEF and preserved VTT and VR seen in AD patients indicate the possible participation of vascular factors in the pathogenesis of AD perhaps at the capillary level.
Batista, Philip; Abai, Babak; Salvatore, Dawn; DiMuzio, Paul
As vascular surgery training paradigms evolve, one measure of success is operative experience. This study assessed the initial operative experience of those graduating from new integrated programs (0+5) vs those from the traditional programs (5+2). National operative case log data supplied by the Accreditation Council for Graduate Medical Education was compiled for vascular surgical residents graduating between 2010 and 2013. Mean case numbers for the 0+5 residents were compared with those for the 5+2 residents (experience from their general surgery residency plus vascular fellowship) for total vascular operations, open vascular operations, endovascular procedures, and total operative experience. The 5+2 trainees performed significantly more procedures than the 0+5 trainees (mean, 1605 vs 1015); however, they performed 12% less vascular procedures (mean, 758 vs 851). No significant differences in total number of open vascular operations (mean, 404 vs 411) or specific open operations for cerebral vascular disease, aneurysm, peripheral obstruction, and access were found. The increase in vascular procedures logged by 0+5 trainees was realized by a 24% increase in endovascular procedures, mainly involving diagnostic arteriography, caval filter placement, and balloon angioplasty. No significant differences were seen in endovascular aneurysm repair (mean, 63 vs 60) and stent placement (mean, 59 vs 60). This report summarizes the first data available for the 0+5 trainee operative experience. Compared with the traditional 5+2 trainees, the 0+5 trainees have (1) equivalent open vascular training and (2) overall superior endovascular training, although this was accounted via an increase in minor procedures. The overall operative experience remains greater for the 5+2 trainees secondary to 2 extra years of training. Further longitudinal studies will be needed to fully characterize the effect of the new 0+5 training paradigm. Published by Elsevier Inc.
Koyama, Teruhide; Ochoa-Callejero, Laura; Sakurai, Takayuki; Kamiyoshi, Akiko; Ichikawa-Shindo, Yuka; Iinuma, Nobuyoshi; Arai, Takuma; Yoshizawa, Takahiro; Iesato, Yasuhiro; Lei, Yang; Uetake, Ryuichi; Okimura, Ayano; Yamauchi, Akihiro; Tanaka, Megumu; Igarashi, Kyoko; Toriyama, Yuichi; Kawate, Hisaka; Adams, Ralf H; Kawakami, Hayato; Mochizuki, Naoki; Martínez, Alfredo; Shindo, Takayuki
Revealing the mechanisms underlying the functional integrity of the vascular system could make available novel therapeutic approaches. We previously showed that knocking out the widely expressed peptide adrenomedullin (AM) or receptor activity-modifying protein 2 (RAMP2), an AM-receptor accessory protein, causes vascular abnormalities and is embryonically lethal. Our aim was to investigate the function of the vascular AM-RAMP2 system directly. We generated endothelial cell-specific RAMP2 and AM knockout mice (E-RAMP2(-/-) and E-AM(-/-)). Most E-RAMP2(-/-) mice died perinatally. In surviving adults, vasculitis occurred spontaneously. With aging, E-RAMP2(-/-) mice showed severe organ fibrosis with marked oxidative stress and accelerated vascular senescence. Later, liver cirrhosis, cardiac fibrosis, and hydronephrosis developed. We next used a line of drug-inducible E-RAMP2(-/-) mice (DI-E-RAMP2(-/-)) to induce RAMP2 deletion in adults, which enabled us to analyze the initial causes of the aforementioned vascular and organ damage. Early after the induction, pronounced edema with enhanced vascular leakage occurred. In vitro analysis revealed the vascular leakage to be caused by actin disarrangement and detachment of endothelial cells. We found that the AM-RAMP2 system regulates the Rac1-GTP/RhoA-GTP ratio and cortical actin formation and that a defect in this system causes the disruption of actin formation, leading to vascular and organ damage at the chronic stage after the gene deletion. Our findings show that the AM-RAMP2 system is a key determinant of vascular integrity and homeostasis from prenatal stages through adulthood. Furthermore, our models demonstrate how endothelial cells regulate vascular integrity and how their dysregulation leads to organ damage.
The Instituto Nacional de Enfermedades Neoplásicas was established by the government of Peru as an institution for the treatment of cancer patients in 1939; it has existed under different names until the current title was adopted in 1952. Between 1980 and 1987, attendance increased by 70% and a new and larger facility came into use at the beginning of 1988. This institution has national responsibility for cancer prevention, detection, treatment, education, and research and is currently organizing satellite treatment centers in other parts of the country. More than 80% of the medical staff has been trained in the institute's residency program, the majority of whom received additional postgraduate training in the United States and Europe; 90% of the medical staff hold academic appointments in medical schools. In 1952 the Institute became the first hospital in Peru with a formal postgraduate training system for various medical disciplines, including surgical oncology and medical oncology. So far we have trained about 500 surgical oncologists who are working in all parts of Peru. The Maes-Heller Institute for Cancer Research forms part of the National Cancer Institute complex. Research will be directed mainly toward new diagnostic and therapeutic approaches, multidisciplinary tumor therapy, and large-scale cancer screening. The Institute focuses on early detection and prevention of cancer and is active in breast self-examination education and antismoking campaigns. It enjoys community support evidenced in the women's organization, Adainen, involved in fundraising; 460 women volunteers give at least 4 hr service per week to the Institute. The Institute has grown from 9,000 patients seen per year in its early days to 215,000 attendances in 1986.
Sallam, Tamer; Cheng, Henry; Demer, Linda L.; Tintut, Yin
Vascular calcification is a common feature of chronic kidney disease, cardiovascular disease, and aging. Such abnormal calcium deposition occurs in medial and/or intimal layers of blood vessels as well as in cardiac valves. Once considered a passive and inconsequential finding, the presence of calcium deposits in the vasculature is widely accepted as a predictor of increased morbidity and mortality. Recognition of the importance of vascular calcification in health is driving research into mechanisms that govern its development, progression, and regression. Diverse, but highly interconnected factors, have been implicated, including disturbances in lipid metabolism, oxidative stress, inflammatory cytokines, and mineral and hormonal balances, which can lead to formation of osteoblast-like cells in the artery wall. A tight balance of procalcific and anticalcific regulators dictates the extent of disease. In this review, we focus on the main regulatory circuits modulating vascular cell calcification. PMID:23269436
Salazar, Gloria M M; Walker, T Gregory
With the technical advances and the increasing availability of sophisticated imaging equipment, techniques, and protocols, and with continually evolving transcatheter endovascular therapies, minimally invasive imaging and treatment options are being routinely used for the clinical management of trauma patients. Thus, the primary treatment algorithm for managing acute vascular trauma now increasingly involves the interventional radiologist or other endovascular specialist. Endovascular techniques represent an attractive option for both stabilizing and definitively treating patients who have sustained significant trauma, with resultant vascular injury. Endovascular treatment frequently offers the benefit of a focused definitive therapy, even in the presence of massive hemorrhage that allows for preservation of major vessels or injured solid organs and serves as an alternative to an open surgical intervention. This article presents an overview of various endovascular techniques that can be used for trauma patients presenting with vascular injuries.
Paiva, L. R.; Ferreira, S. C.; Martins, M. L.
Cancer therapy requires anticancer agents capable of efficient and uniform systemic delivery. One promising route to their development is nanotechnology. Here, a previous model for cancer chemotherapy based on a nanosized drug carrier (Paiva et al., 2011) is extended by including tissue vasculature and a three-dimensional growth. We study through computer simulations the therapy against tumors demanding either large or small nutrient supplies growing under different levels of tissue vascularization. Our results indicate that highly vascularized tumors demand more aggressive therapies (larger injected doses administrated at short intervals) than poorly vascularized ones. Furthermore, nanoparticle endocytic rate by tumor cells, not its selectivity, is the major factor that determines the therapeutic success. Finally, our finds indicate that therapies combining cytotoxic agents with antiangiogenic drugs that reduce the abnormal tumor vasculature, instead of angiogenic drugs that normalize it, can lead to successful treatments using feasible endocytic rates and administration intervals.
Magness, Ronald R.
Maternal alcohol consumption during pregnancy is a significant field of scientific exploration primarily because of its negative effects on the developing fetus, which is specifically defined as fetal alcohol spectrum disorders. Though the effects on the mother are less explored compared with those on the fetus, alcohol produces multiple effects on the maternal vascular system. Alcohol has major effects on systemic hemodynamic variables, endocrine axes, and paracrine factors regulating vascular resistance, as well as vascular reactivity. Alcohol is also reported to have significant effects on the reproductive vasculature including alterations in blood flow, vessel remodeling, and angiogenesis. Data presented in this review will illustrate the importance of the maternal vasculature in the pathogenesis of fetal alcohol spectrum disorders and that more studies are warranted in this field. PMID:22730388
Knutsson, Karl Anders; De Benedetto, Umberto; Querques, Giuseppe; Del Turco, Claudia; Bandello, Francesco; Lattanzio, Rosangela
Primitive retinal vascular abnormalities are benign conditions of the retinal circulation that comprise vascular tumors and telangiectasias. The principal vascular tumors of the retina include retinal capillary hemangioma, cavernous hemangioma of the retina, racemose hemangiomatosis of the retina and retinal vasoproliferative tumor, while primary retinal telangiectasias include Coats' disease, Leber's miliary aneurysms and idiopathic juxtafoveal telangiectasias. In most cases, these alterations result in significant visual impairment due to exudation determined by the structural abnormalities of the retinal vasculature. The aim of this review is to assess the different clinical and diagnostic features of the single pathological entities and to discuss the available treatment modalities including the onset of intravitreal antivascular endothelial growth factor therapy. Copyright © 2012 S. Karger AG, Basel.
Bhalla, A; Singh, R; Sachdev, A; D'Cruz, S; Duseja, A
Over the last decade, various studies have been reported to evaluate the circadian pattern of cardiovascular and cerebro-vascular diseases. The data from Indian population is lacking. We undertook this prospective observational study to evaluate the circadian variation in disorders like cerebro-vascular accidents and transient ischemic attacks. Total of 146 patients (events) were studied. Only 10 patients had TIA's. 55% had hemorrhage and 45% had infarction. The 24 hours period was divided into 6 equal portions of 4 hours each. The maximum events were seen between 4 am to 8 am and 12 noon to 4 pm (23.28%) each. Minimum events were seen between 12 midnight to 4 am 14/146 - 9.58%). The circadian variation in occurrence of cerebro-vascular disorders was present with two equal peaks.
Lee, B C; Herzberg, L; Zimmerman, R D; Deck, M D
Fifteen vascular malformations, including six supratentorial arteriovenous malformations (AVMs), three venous malformations, and six brainstem vascular malformations, were examined on 0.5 T magnetic resonance (MR) and GE 9800 and 8800 computed tomographic (CT) scanners. All the malformations were shown by MR, and the arterial and venous drainage of AVMs was precisely delineated. Hematoma was always differentiated from calcification by MR signal characteristics. Increased signal in the brain parenchyma was often seen adjacent to AVMs. The signal of blood within venous malformations altered with spin-echo techniques using various repetition times and was distinguished from rapidly flowing blood in AVMs that lacked signal in all imaging sequences. Brainstem malformations were seldom demonstrated by angiography. Hemorrhage was common and was invariably associated with multiple areas of absent signal that may have represented abnormal vessels. These appearances are distinct from those of intrinsic tumors and are probably pathognomonic of brainstem vascular malformations.
The long-term survival and quality of life of patients on hemodialysis (HD) is dependant on the adequacy of dialysis via an appropriately placed vascular access. The optimal vascular access is unquestionably the autologous arteriovenous fistula (AVF), with the most common method being the conventional radio-cephalic fistula at the wrist. Recent clinical practice guidelines recommend the creation of native fistula or synthetic graft before the start of chronic HD therapy to prevent the need for complication-prone dialysis catheters. This could also have a beneficial effect on the rapidity of worsening kidney failure. A multidisciplinary approach (nephrologists, surgeons, radiologists and nurses) should improve the HD outcome by promoting the use of AVF. An important additional component of this program is the Doppler ultrasound for preoperative vascular mapping. Such an approach may be realized without unsuccessful surgical explorations, with a minimal early failure rate and a high maturation, even in patients with diabetes mellitus.
Marulanda, Juliana; Alqarni, Saleh; Murshed, Monzur
Mineralization of bone and tooth extracellular matrix (ECM) is a physiologic process, while soft tissue mineralization, also known as ectopic mineralization (calcification), is a pathologic condition. Vascular calcification is common in aging and also in a number of genetic and metabolic disorders. The calcific deposits in arteries complicate the prognosis and increase the morbidity in diseases such as atherosclerosis, diabetes and chronic kidney disease (CKD). To completely understand the pathophysiology of these lifethreatening diseases, it is critical to elucidate the molecular mechanisms underlying vascular calcification. Unveiling these mechanisms will eventually identify new therapeutic targets and also improve the management of the associated complications. In the current review, we discussed the common determinants of ECM mineralization, the mechanism of vascular calcification associated with several human diseases and outlined the most common therapeutic approaches to prevent its progression.
Shelling, Michael L; Federman, Daniel G; Prodanovich, Srdjan; Kirsner, Robert S
Psoriasis is an immune disease most commonly recognized for its skin and joint manifestations. These produce significant physical, social, and psychological distress in affected patients and resultant reductions in their quality of life. As expected, these concerns are vital in providing symptomatic improvement and in selecting an individualized therapy. Yet, the approach in management of these patients is likely to change given the growing body of evidence linking psoriasis and vascular disease. Stemming from an anecdotally described relationship, the association between psoriasis and vascular disease has become a focus of current research to further elucidate the pathophysiology underlying and connecting these two diseases. This article includes a review of the classical cardiovascular risk factors, the atherothrombotic markers, and the environmental stressors associated with psoriasis, as well as a critical review of the observed vascular diseases, the proposed mechanism of atherosclerosis, and the benefits of treatment of psoriasis.
Postnov, D D; Postnov, D E; Marsh, D J; Holstein-Rathlou, N-H; Sosnovtseva, O V
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 to learn about processes not directly amenable to experimentation. We demonstrate that: (i) the nearest nephrons are synchronized in-phase due to a vascular propagated electrical coupling, (ii) the next few branching levels display a formation of phase-shifted patterns due to hemodynamic coupling and mode elimination, and (iii) distantly located areas show asynchronous behavior or, if all nephrons and branches are perfectly identical, an infinitely long transient behavior. These results contribute to the understanding of mechanisms responsible for the highly dynamic and limited synchronization observed among groups of nephrons despite of the fairly strong interaction between the individual units.
Karavias, D; Korovessis, P; Filos, K S; Siamplis, D; Petrocheilos, J; Androulakis, J
Seventeen patients, aged 11-67 years (mean, 32.6), with major vascular injuries associated with traumatic orthopaedic injuries, were treated operatively in the authors' institution over a 4-year period. The most common mechanism of trauma was a high-energy injury (70.8%), and the rate of open injuries was 88.2%; 64.9% of the injuries were located in the lower extremities. The treatment protocol consisted of aggressive resuscitation; Doppler imaging and, when necessary, angiography; stable bone fixation with subsequent vascular repair; and extended wound debridement. The vascular repair for arterial lacerations consisted of (a) end-to-end anastomosis (47.2%); (b) interpositional homologous vein graft (23.6%); (c) vascular decompression through fracture distraction in one patient (5.9%); (d) xenograft interposition (in one patient; 5.9%); (e) venous repair (in three patients; 17.7%); and (f) embolectomy (in all patients). Three vascular reoperations (17.7%) were necessary because of rupture of the anastomosis. The authors' preferred bone stabilization method was external fixation, which was used in 47.2% of cases. Amputation was performed in three cases (17.7%) as a salvage operation. Although six patients (35.4%) were admitted with delayed shock (mean duration, 73.6 +/- 27.8 min), this led to a lethal outcome due to shock lung in only one patient. Another patient developed massive lung embolism 3 months postoperatively and died. The authors believe that this well-organized approach, based on a specific treatment protocol, for patients with severe orthopaedic trauma and concomitant vascular injury, not only improves outcome but gives good to excellent functional results in the majority of patients.
Arribas, Silvia M; Hinek, Aleksander; González, M Carmen
Blood vessels are dynamic structures composed of cells and extracellular matrix (ECM), which are in continuous cross-talk with each other. Thus, cellular changes in phenotype or in proliferation/death rate affect ECM synthesis. In turn, ECM elements not only provide the structural framework for vascular cells, but they also modulate cellular function through specific receptors. These ECM-cell interactions, together with neurotransmitters, hormones and the mechanical forces imposed by the heart, modulate the structural organization of the vascular wall. It is not surprising that pathological states related to alterations in the nervous, humoral or haemodynamic environment-such as hypertension-are associated with vascular wall remodeling, which, in the end, is deleterious for cardiovascular function. However, the question remains whether these structural alterations are simply a consequence of the disease or if there are early cellular or ECM alterations-determined either genetically or by environmental factors-that can predispose to vascular remodeling independent of hypertension. Elastic fibres might be key elements in the pathophysiology of hypertensive vascular remodeling. In addition to the well known effects of hypertension on elastic fibre fatigue and accelerated degradation, leading to loss of arterial wall resilience, recent investigations have highlighted new roles for individual components of elastic fibres and their degradation products. These elements can act as signal transducers and regulate cellular proliferation, migration, phenotype, and ECM degradation. In this paper, we review current knowledge regarding components of elastic fibres and discuss their possible pathomechanistic associations with vascular structural abnormalities and with hypertension development or progression.
Patel, Chandrakant R; Lane, John R; Spector, Michael L; Smith, Philip C
The purpose of this series is to describe the prenatal echocardiographic findings of vascular rings. The 3-vessel and trachea view consists of the axial view of the upper mediastinum. The normal left aortic arch appears as a V-shaped confluence of the ductus arteriosus and aortic arch, with the trachea situated posterior and to the right. No vessel should encircle the trachea. The diagnoses of vascular rings were made prenatally and were confirmed in all patients postnatally. Six fetuses had diagnoses of vascular rings. The mean gestational age at diagnosis was 23.3 weeks (range, 18-31 weeks). The indications for fetal echocardiography were family history of congenital heart disease, echogenic focus in the left ventricle, and abnormal 4-chamber view. There were 2 fetuses with a double aortic arch; 3 fetuses with a right aortic arch, an aberrant left subclavian artery, and a left ductus arteriosus; and 1 with a right circumflex aortic arch with a left ductus arteriosus and an aberrant left subclavian artery. Two fetuses had associated structural cardiac defects, 1 with an unbalanced atrioventricular septal defect and trisomy 21 and the other with a double-outlet right ventricle, pulmonary atresia, and multiple other congenital anomalies. Vascular rings can be accurately diagnosed prenatally with recognition of a vascular structure that courses around the trachea and absence of the usual V-shaped relationship of the aortic and ductal arches. The color Doppler findings and the presence of a ductus arteriosus aid in identifying various components of the vascular ring.
Heme oxygenase-1 (HO-1) metabolizes heme to generate carbon monoxide (CO), biliverdin, and iron. Biliverdin is subsequently metabolized to bilirubin by biliverdin reductase. HO-1 has recently emerged as a promising therapeutic target in the treatment of vascular disease. Pharmacological induction or gene transfer of HO-1 ameliorates vascular dysfunction in animal models of atherosclerosis, post-angioplasty restenosis, vein graft stenosis, thrombosis, myocardial infarction, and hypertension, while inhibition of HO-1 activity or gene deletion exacerbates these disorders. The vasoprotection afforded by HO-1 is largely attributable to its end products: CO and the bile pigments, biliverdin and bilirubin. These end products exert potent anti-inflammatory, antioxidant, anti-apoptotic, and anti-thrombotic actions. In addition, CO and bile pigments act to preserve vascular homeostasis at sites of arterial injury by influencing the proliferation, migration, and adhesion of vascular smooth muscle cells, endothelial cells, endothelial progenitor cells, or leukocytes. Several strategies are currently being developed to target HO-1 in vascular disease. Pharmacological induction of HO-1 by heme derivatives, dietary antioxidants, or currently available drugs, is a promising near-term approach, while HO-1 gene delivery is a long-term therapeutic goal. Direct administration of CO via inhalation or through the use of CO-releasing molecules and/or CO-sensitizing agents provides an attractive alternative approach in targeting HO-1. Furthermore, delivery of bile pigments, either alone or in combination with CO, presents another avenue for protecting against vascular disease. Since HO-1 and its products are potentially toxic, a major challenge will be to devise clinically effective therapeutic modalities that target HO-1 without causing any adverse effects.
Beck, Thomas; Godenschwager, Christian; Bauer, Miriam; Bernhardt, Dominik; Dillmann, Rüdiger
Automatic examination of medical images becomes increasingly important due to the rising amount of data. Therefore automated methods are required which combine anatomical knowledge and robust segmentation to examine the structure of interest. We propose a statistical model of the vascular tree based on vascular landmarks and unbranched vessel sections. An undirected graph provides anatomical topology, semantics, existing landmarks and attached vessel sections. The atlas was built using semi-automatically generated geometric models of various body regions ranging from carotid arteries to the lower legs. Geometric models contain vessel centerlines as well as orthogonal cross-sections in equidistant intervals with the vessel contour having the form of a polygon path. The geometric vascular model is supplemented by anatomical landmarks which are not necessarily related to the vascular system. These anatomical landmarks define point correspondences which are used for registration with a Thin-Plate-Spline interpolation. After the registration process, the models were merged to form the statistical model which can be mapped to unseen images based on a subset of anatomical landmarks. This approach provides probability distributions for the location of landmarks, vessel-specific geometric properties including shape, expected radii and branching points and vascular topology. The applications of this statistical model include model-based extraction of the vascular tree which greatly benefits from vessel-specific geometry description and variation ranges. Furthermore, the statistical model can be applied as a basis for computer aided diagnosis systems as indicator for pathologically deformed vessels and the interaction with the geometric model is significantly more user friendly for physicians through anatomical names.
Schindler, Ehrenfried; Schears, Gregory J; Hall, Stuart R; Yamamoto, Tomohiro
In pediatric patients vascular access is often more difficult than in adults because of the smaller size of the vessels and the inability of the patient to cooperate without deep sedation or general anesthesia. Therefore Ultrasound has already become an invaluable tool for vascular access, but the full potential of ultrasound has yet to be fully realized. Improvements in image quality and a better understanding of optimal insertion techniques continue to help clinicians safely and efficiently place catheters with fewer complications. The probes used for the vascular access are mainly linear and convex type. Higher- frequency ultrasound provides a vivid image; however, the signals are remarkably attenuated. Therefore, the choice of the probe with appropriate frequency is essential. As blood vessels are relatively easily identified with ultrasound, ultrasound-guided vascular access does not require as sharp images as ultrasound-guided nerve block. For pediatric vascular access, the linear probe with 5-15 MHz, 2-5 cm depth is ideal and adequate for almost all cases. Ultrasound-guided vascular access has two main approaches: 'long-axis' or 'in-plane approach' and 'short-axis' or 'transverse approach'. The long-axis approach visualizes the vessel along the insertion pathway and is commonly used to monitor the entire approach of the needle into the vessel. The short-axis approach is easier to show the positional relationship and depth of target vessels, but it is much harder to follow the needle tip within the tissues. The use of 'real-time' ultrasound has been shown to increase first insertion success, reduce access time, have a higher overall success, and reduce arterial puncture. As the technology continues to improve the use of ultrasound will become as ubiquitous as the lines themselves. © 2012 Blackwell Publishing Ltd.
Parsons-Wingerter, Patricia A.; Vickerman, Mary B.; Keith, Patricia A.
VESsel GENeration (VESGEN) Analysis is an automated software that maps and quantifies effects of vascular regulators on vascular morphology by analyzing important vessel parameters. Quantification parameters include vessel diameter, length, branch points, density, and fractal dimension. For vascular trees, measurements are reported as dependent functions of vessel branching generation. VESGEN maps and quantifies vascular morphological events according to fractal-based vascular branching generation. It also relies on careful imaging of branching and networked vascular form. It was developed as a plug-in for ImageJ (National Institutes of Health, USA). VESGEN uses image-processing concepts of 8-neighbor pixel connectivity, skeleton, and distance map to analyze 2D, black-and-white (binary) images of vascular trees, networks, and tree-network composites. VESGEN maps typically 5 to 12 (or more) generations of vascular branching, starting from a single parent vessel. These generations are tracked and measured for critical vascular parameters that include vessel diameter, length, density and number, and tortuosity per branching generation. The effects of vascular therapeutics and regulators on vascular morphology and branching tested in human clinical or laboratory animal experimental studies are quantified by comparing vascular parameters with control groups. VESGEN provides a user interface to both guide and allow control over the users vascular analysis process. An option is provided to select a morphological tissue type of vascular trees, network or tree-network composites, which determines the general collections of algorithms, intermediate images, and output images and measurements that will be produced.
Yasunari, K; Kohno, M; Yoshikawa, J
Hyperglycemia is an important causative factor in the development of micro- and macrovascular complications in diabetes. It activates polyol pathway and protein kinase C, which result in the increase in insulin resistance and oxidative stress in vascular tissues, leading to the accelerated atherosclerosis. Increased hematocrit and blood viscosity are observed in diabetes, which contribute to an increased risk of thrombosis and accelerated vasculopathy. Blood glucose control as well as blood pressure control are important in the prevention of diabetic vascular complications as evidenced by large-scale interventional studies.
Pic Gomis, L; Gomis, R
The authors relate their experience concerning the vascularized iliac crest flap. In the first chapter, they detail the anatomic vascularized osteocutaneous iliac crest. Blood supply arises from the deep and superficial circonflexe iliac artery. Many anastomoses connect the two systems. In the second chapter, they detail the operative technique of free and pedicule hone iliac crest flap. Composite cutaneous bone flaps are also detailed. In the third chapter, they detail informations about treatment of distal radius bone defects with associated skeen flap if necessary.
Distribution and structural networks permeate virtually all life, from the cellular to the organismic level. They have allowed organisms to grow in size and complexity by ensuring efficient distribution of nutrients and structural support. Given their importance, these vascular and structural webs have been under strong evolutionary selection and their form frequently reflects important aspects of their function. We discuss the design principles behind the evolution of the architecture and topology of vascular and structural networks and present some examples (leaf venation, arterial vasculature of the neocortex and others) that elucidate them.
Nicholson, Anthony A.
It's been 30 years since an endovascular technique to control traumatic hemorrhage was first described. Despite major technical advances in both diagnostic and therapeutic technology, and a great deal of experience since then, endovascular techniques are rarely considered as part of frontline management for vascular trauma. This review considers the literature and calls for better planning and implementation of diagnostic and image=guided therapeutic facilities. Endovascular techniques should be an essential part of vascular trauma management along with endovascular specialists, partners in trauma teams.
Pattanaik, Debendra; Brown, Monica; Postlethwaite, Arnold E
Systemic sclerosis (SSc) is an acquired multiorgan connective tissue disease with variable mortality and morbidity dictated by clinical subset type. The etiology of the basic disease and pathogenesis of the systemic autoimmunity, fibrosis, and fibroproliferative vasculopathy are unknown and debated. In this review, the spectrum of vascular abnormalities and the options currently available to treat the vascular manifestations of SSc are discussed. Also discussed is how the hallmark pathologies (ie, how autoimmunity, vasculopathy, and fibrosis of the disease) might be effected and interconnected with modulatory input from lysophospholipids, sphingosine 1-phosphate, and lysophosphatidic acid. PMID:22096374
Church, Joseph T; Jarboe, Marcus D
Vascular access procedures are an important and frequent component of the day-to-day practice of the pediatric surgeon. Most access procedures can be performed percutaneously via Seldinger or modified Seldinger technique and are aided by technology, such as ultrasound and fluoroscopy. Complications, such as infection, do occur, and the pediatric surgeon should be able to diagnose and treat these when they arise. The indications, techniques, and complications of vascular access are covered in this article. Copyright Â© 2016 Elsevier Inc. All rights reserved.
Bhende, Harish; Laud, Nanadkishore; Deore, Sandeep; Shashidhar, V
In Klippel–Trenaunay syndrome, vascular malformations are not only in skin and superficial soft tissues but also in deep tissues like muscles bones and joints. It is well documemted that these recurrent intraarticular bleeds can cause early arthritis and joint pain. Performing arthroplasty in such patients is difficult and fraught with complications. We describe such a case where navigated total knee arthroplasty was performed with success to avoid the problems of intra medullary alignment used in the presence of intra medullary vascular malformations. We also suggest certain measures when knee arthroplasty is considered in such patients. PMID:26538765
Chowdhry, Shakeel A; Spetzler, Robert F
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.
Fan, Hua; Chen, Hao-Yu; Ma, Hong-Jie; Chang, Zheng; Yin, Hai-Quan; Ng, Danny Siu-Chun; Cheung, Carol Y; Hu, Shan; Xiang, Xiang; Tang, Shi-Bo; Li, Shuang-Nong
Background: Morphological changes of the vasculature system in patients with myopia have been observed by Doppler ultrasound and fundus fluorescein angiography (FFA); however, these studies have limitations. Doppler ultrasound provides low-resolution images which are mainly obtained from visualized large vessels, and FFA is an invasive examination. Optic coherence tomography (OCT) angiography is a noninvasive, high-resolution measurement for vascular density. The purpose of this study was to investigate the change of vascular density in myopic eyes using OCT angiography. Methods: This cross-sectional study includes a total of 91 eyes from 47 participants including control, moderate, and high myopia that were evaluated by OCT angiography. Patients with myopia were recruited from the Refractive Department, Shenzhen Aier Eye Hospital, from August 5, 2015 to April 1, 2016. Emmetropic eyes were from healthy volunteers. The vascular density at macula and optic disc regions, ganglion cell complex (GCC) thickness, and retinal nerve fiber layer (RNFL) thickness were measured. Their relationships with axial length (AL) and refractive error were analyzed. One-way analysis of variance (ANOVA), Pearson's correlation, and generalized estimating equation were used for statistical analysis. Results: Both superficial and deep macular vascular density were highest in control (25.64% ± 3.76% and 37.12% ± 3.66%, respectively), then in moderate myopia (21.15% ± 5.33% and 35.35% ± 5.50%, respectively), and lowest in high myopia group (19.64% ± 3.87% and 32.81% ± 6.29%, respectively) (F = 13.74 and 4.57, respectively; both P < 0.001). Both superficial (β = −0.850 and 0.460, respectively) and deep (β = −0.766 and 0.396, respectively) macular vascular density were associated with AL and spherical equivalent (all P < 0.001). Superficial macular vascular density was associated with GCC thickness (β = 0.244, P = 0.040), independent of spherical equivalent. The vascular density in
Reslan, Ossama M.; Khalil, Raouf A.
Cardiovascular disease (CVD) is more common in men and postmenopausal women (Post-MW) than premenopausal women (Pre-MW). Despite recent advances in preventive measures, the incidence of CVD in women has shown a rise that matched the increase in the Post-MW population. The increased incidence of CVD in Post-MW has been related to the decline in estrogen levels, and hence suggested vascular benefits of endogenous estrogen. Experimental studies have identified estrogen receptor ERα, ERβ and a novel estrogen binding membrane protein GPR30 (GPER) in blood vessels of humans and experimental animals. The interaction of estrogen with vascular ERs mediates both genomic and non-genomic effects. Estrogen promotes endothelium-dependent relaxation by increasing nitric oxide, prostacyclin, and hyperpolarizing factor. Estrogen also inhibits the mechanisms of vascular smooth muscle (VSM) contraction including [Ca2+]i, protein kinase C and Rho-kinase. Additional effects of estrogen on the vascular cytoskeleton, extracellular matrix, lipid profile and the vascular inflammatory response have been reported. In addition to the experimental evidence in animal models and vascular cells, initial observational studies in women using menopausal hormonal therapy (MHT) have suggested that estrogen may protect against CVD. However, randomized clinical trials (RCTs) such as the Heart and Estrogen/progestin Replacement Study (HERS) and the Women’s Health Initiative (WHI), which examined the effects of conjugated equine estrogens (CEE) in older women with established CVD (HERS) or without overt CVD (WHI), failed to demonstrate protective vascular effects of estrogen treatment. Despite the initial set-back from the results of MHT RCTs, growing evidence now supports the ‘timing hypothesis’, which suggests that MHT could increase the risk of CVD if started late after menopause, but may produce beneficial cardiovascular effects in younger women during the perimenopausal period. The choice of
Weilert, Frank; Binmoeller, Kenneth F
The gastrointestinal tract provides a unique window to access vascular structures in the mediastinum and abdomen. The advent of interventional endoscopic ultrasound (EUS) has enabled access to these structures with standard fine-needle aspiration. EUS-guided treatment of varices has been largely reserved as rescue therapy for refractory bleeding but has theoretic advantages over conventional endoscopy-guided treatment. Data are limited and multicenter, prospective controlled trials are needed to show clinical effectiveness and safety in humans. The development of new tools designed for EUS-guided vascular therapy is needed. Copyright © 2012 Elsevier Inc. All rights reserved.
Laurie, Steven S.
In the lung, acute reductions in oxygen lead to hypoxic pulmonary vasoconstriction, whereas prolonged exposures to hypoxia result in sustained vasoconstriction, pulmonary vascular remodeling, and the development of pulmonary hypertension. Data from both human subjects and animal models implicate a role for hypoxia-inducible factors (HIFs), oxygen-sensitive transcription factors, in pulmonary vascular responses to both acute and chronic hypoxia. In this review, we discuss work from our laboratory and others supporting a role for HIF in modulating hypoxic pulmonary vasoconstriction and mediating hypoxia-induced pulmonary hypertension, identify some of the downstream targets of HIF, and assess the potential to pharmacologically target the HIF system. PMID:24336881
Tamaki, Hiromichi; Chatterjee, Soumya; Langford, Carol A
Peripheral and tissue eosinophilia can be a prominent feature of several unique rheumatologic and vascular diseases. These diseases span a wide range of clinical features, histologic findings, therapeutic approaches, and outcomes. Despite the rare nature of these entities--which makes large-scale studies challenging--knowledge has continued to grow regarding their epidemiology, pathophysiology, and management. This review compares and contrasts 5 rheumatologic and vascular conditions in which eosinophilia can be seen: eosinophilic granulomatosis with polyangiitis (Churg-Strauss), immunoglobulin G4-related disease, diffuse fasciitis with eosinophilia, eosinophilia-myalgia syndrome, and eosinophilic myositis. Copyright © 2015 Elsevier Inc. All rights reserved.
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
de Luis, Daniel A; Izaola, Olatz; de la Fuente, Beatriz; Muñoz-Calero, Paloma; Franco-Lopez, Angeles
Introducción: las enfermedades neurodegenerativas producen alteraciones en el nivel de conciencia o en los mecanismos de la deglución que con frecuencia hacen necesario un soporte nutricional especializado. Objetivo: revisar el riesgo de desnutrición, así como su tratamiento, en pacientes con enfermedad cerebral vascular, enfermedad de Parkinson, demencia y esclerosis lateral amiotrófica. Desarrollo: las enfermedades neurológicas degenerativas son una de las principales indicaciones de soporte nutricional en nuestro país. En los procesos agudos (enfermedad vascular cerebral), el correcto manejo nutricional se relaciona con una mejor evolución y con una disminución de las complicaciones. En los procesos neurodegenerativos crónicos (esclerosis lateral amiatrófica y demencia), la malnutrición es un problema importante que empeora el pronóstico de estos pacientes siendo, necesario un correcto manejo de la disfagia y sus complicaciones, así como la utilización de diferentes etapas de soporte nutricional. Una correcta valoración nutricional de estos pacientes, así como un claro esquema de intervención nutricional, es imprescindible en el seguimiento de su enfermedad. Por último, en la enfermedad de Parkinson avanzada, el soporte nutricional, como en las enfermedades neurodegenerativas anteriores, es de vital importancia, sin olvidarnos de la carga proteica y su distribución en la dieta de estos pacientes. Las sociedades científicas internacionales (American Society for Parenteral and Enteral Nutrition ASPEN) recomiendan, con un grado de evidencia B, realizar un cribaje de malnutrición a los pacientes con enfermedades neurológicas. Conclusiones: una correcta valoración nutricional, así como un adecuado soporte nutricional deben formar parte del proceso diagnóstico y terapéutico de estas enfermedades.
Kostopoulos, Vasileios K.
Since 1976, experimental and clinical studies have suggested the superiority of vascularized nerve grafts. In this study, a 27-year experience of the senior author is presented regarding vascularized nerve grafts and fascia for complex upper extremity nerve reconstruction. The factors influencing outcomes as well as a comparison with conventional nerve grafts is presented. Since 1981, 21 vascularized nerve grafts, other than vascularized ulnar nerve, were used for reconstruction of nerve injuries in the upper extremity. Indications were prolonged denervation time, failure of the previously used conventional nerve grafts, and excessive scar in the recipient site. Injury was in the hand/wrist area (n = 5), in the forearm (n = 4), in the elbow (n = 2), in the arm (n = 4), or in the plexus (n = 6). Vascularized sural (n = 9), saphenous (n = 8), superficial radial (n = 3), and peroneal (superficial and deep) nerves were used. The mean follow-up was 31.4 months. Vascularized nerve grafts for upper extremity injuries provided good to excellent sensory return in severely scarred upper extremities in patients in whom conventional nerve grafts had failed. They have also provided relief of causalgia after painful neuroma resection and motor function recovery in selective cases even for above the elbow injuries. Small diameter vascularized nerve grafts should be considered for bridging long nerve gaps in regions of excessive scar or for reconstructions where conventional nerve grafts have failed. PMID:19381727
Timur, A. A.; Driscoll, D. J.
Vascular morphogenesis is a vital process for embryonic development, normal physiologic conditions (e.g. wound healing) and pathological processes (e.g. atherosclerosis, cancer). Genetic studies of vascular anomalies have led to identification of critical genes involved in vascular morphogenesis. A susceptibility gene, VG5Q (formally named AGGF1), was cloned for Klippel-Trenaunay syndrome (KTS). AGGF1 encodes a potent angiogenic factor, and KTS-associated mutations enhance angiogenic activity of AGGF1, defining ‘increased angiogenesis’ as one molecular mechanism for the pathogenesis of KTS. Similar studies have identified other genes involved in vascular anomalies as important genes for vascular morphogenesis, including TIE2, VEGFR-3, RASA1, KRIT1, MGC4607, PDCD10, glomulin, FOXC2, NEMO, SOX18, ENG, ACVRLK1, MADH4, NDP, TIMP3, Notch3, COL3A1 and PTEN. Future studies of vascular anomaly genes will provide insights into the molecular mechanisms for vascular morphogenesis, and may lead to the development of therapeutic strategies for treating these and other angiogenesis-related diseases, including coronary artery disease and cancer. PMID:15905966
Katsiki, N; Papadopoulou, S K; Fachantidou, A I; Mikhailidis, D P
Smoking, both active and passive, is an established vascular risk factor. The present narrative review considers the effects of different forms of smoking (i.e. cannabis, cigar, pipe, smokeless tobacco and cigarette) on cardiovascular risk. Furthermore, the impact of smoking on several vascular risk factors [e.g. hypertension, diabetes mellitus (DM), dyslipidaemia and haemostasis] and on vascular diseases such as coronary heart disease (CHD), peripheral arterial disease (PAD), abdominal aortic aneurysms (AAA) and carotid arterial disease, is discussed. The adverse effects of all forms of smoking and the interactions between smoking and established vascular risk factors highlight the importance of smoking cessation in high-risk patients in terms of both primary and secondary vascular disease prevention. Healthcare providers should discourage people (especially the young) from becoming smokers, strongly encourage all vascular patients to stop smoking and support those who decide to quit by pharmaceutical and psychological interventions. In high-risk populations such as patients with CHD, DM and/or PAD, smoking cessation should always be a part of a multifactorial treatment to reduce vascular risk. Copyright © 2013 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.
Henry, Jeffrey J D; Yu, Jian; Wang, Aijun; Lee, Randall; Fang, Jun; Li, Song
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.
Wassef, Michel; Blei, Francine; Adams, Denise; Alomari, Ahmad; Baselga, Eulalia; Berenstein, Alejandro; Burrows, Patricia; Frieden, Ilona J; Garzon, Maria C; Lopez-Gutierrez, Juan-Carlos; Lord, David J E; Mitchel, Sally; Powell, Julie; Prendiville, Julie; Vikkula, Miikka
Vascular anomalies represent a spectrum of disorders from a simple "birthmark" to life- threatening entities. Incorrect nomenclature and misdiagnoses are commonly experienced by patients with these anomalies. Accurate diagnosis is crucial for appropriate evaluation and management, often requiring multidisciplinary specialists. Classification schemes provide a consistent terminology and serve as a guide for pathologists, clinicians, and researchers. One of the goals of the International Society for the Study of Vascular Anomalies (ISSVA) is to achieve a uniform classification. The last classification (1997) stratified vascular lesions into vascular malformations and proliferative vascular lesions (tumors). However, additional disease entities have since been identified that are complex and less easily classified by generic headings, such as capillary malformation, venous malformation, lymphatic malformation, etc. We hereby present the updated official ISSVA classification of vascular anomalies. The general biological scheme of the classification is retained. The section on tumors has been expanded and lists the main recognized vascular tumors, classified as benign, locally aggressive or borderline, and malignant. A list of well-defined diseases is included under each generic heading in the "Simple Vascular Malformations" section. A short definition is added for eponyms. Two new sections were created: one dealing with the malformations of individually named vessels (previously referred to as "truncular" malformations); the second groups lesions of uncertain or debated nature (tumor versus malformation). The known genetic defects underlying vascular anomalies are included in an appendix. This classification is meant to be a framework, acknowledging that it will require modification as new scientific information becomes available. Copyright © 2015 by the American Academy of Pediatrics.
Gyedu, Adam; Stewart, Barclay T; Nakua, Emmanuel; Quansah, Robert; Donkor, Peter; Mock, Charles; Hardy, Mark A; Yangni-Angate, Koffi Herve
Introduction This study aimed to describe national peripheral vascular disease (PVD) risk and health burden and vascular care capacity in Ghana. The gap between PVD burden and vascular care capacity in a low- and middle-income country (LMIC) is defined and capacity improvement priorities identified. Methods Data to estimate PVD risk factor burden were obtained from: i) World Health Organization’s Study on Global Ageing and Health (SAGE), Ghana; and ii) Institute of Health Metrics and Evaluation Global Burden of Disease database (IHME GBD). In addition, a novel nationwide assessment of vascular care capacity was performed, with 20 vascular care items assessed at 40 hospitals in Ghana. Factors contributing to specific item deficiency were also described. Results From the SAGE database, there were 4,305 respondents aged at least 50 years with data to estimate PVD risk. Out of these 57% were at moderate to high PVD risk with ≥3 risk factors, thus giving 1,654,557 persons when extrapolated nationally. Using IHME GBD data, the estimated disability-adjusted life years incurred from PVD increased 5-fold from 1990 to 2010 (1.3 to 3.2 per 100,000 persons, respectively). Vascular care capacity assessment demonstrated marked deficiencies in items for diagnosis, perioperative and vascular surgical care. Deficiencies were most often due to absence of equipment, lack of training and technology breakage. Conclusion Risk factor reduction and management as well as optimization of current resources are paramount to avoid the large burden of peripheral vascular disease falling on healthcare systems in low- and middle-income countries that are not well equipped to handle vascular surgical care, and for which rapid development of such capacity would be difficult and expensive. PMID:26560502
Descombes, E; Droz, D; Drouet, L; Grünfeld, J P; Lesavre, P
We retrospectively studied the prevalence, histologic features, clinical correlations, and long-term outcome of the intrarenal vascular lesions of lupus nephritis (LN) in a series of 169 renal biopsies performed between 1980 and 1994 in 132 patients with systemic lupus erythematosus. The most common vascular lesions were nonspecific sclerotic changes, found in 37% of the biopsies (24% if only the cases with moderate to severe changes are considered). The other common vascular lesions were "immunoglobulin microvascular casts," found in 24% of the biopsies. Vasculitis and thrombotic microangiopathy were rare lesions and were seen in only 4 (2.4%) and 1 (0.6%) cases, respectively. Isolated sclerotic vascular changes were present in biopsies from older patients with a longer duration of LN, compared with the group with no vascular lesions, and were associated with a significantly higher prevalence of hypertension. Overall, however, the long-term renal and patient survival of this group did not differ significantly from that of the patients without vascular changes. Immunoglobulin microvascular casts (IMCs) ("lupus vasculopathy") were characterized by the presence of immunoglobulin deposition within the glomerular capillaries and small arterioles. In the present study we extensively investigated the morphologic and immunologic features of this lesion. The lesions were notable for the absence of endothelial or parietal vascular lesions and of fibrin, platelets, and leukocytes, which indicates that thrombosis is not involved in the vascular obstruction. According to our data immunoglobulin precipitation in the microvasculature seems to play a central role in the pathogenesis of this lesion, which is why we propose the term "immunoglobulin microvascular casts." In general, IMCs were associated with the most severe and active forms of diffuse proliferative lupus nephritis (World Health Organization [WHO] class IV). However our data show that, in contrast to previous studies
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.
Vascular tissues, xylem and phloem, are differentiated from meristematic cells, procambium, and vascular cambium. Auxin and cytokinin have been considered essential for vascular tissue differentiation; this is supported by recent molecular and genetic analyses. Xylogenesis has long been used as a model for study of cell differentiation, and many genes involved in late stages of tracheary element formation have been characterized. A number of mutants affecting vascular differentiation and pattern formation have been isolated in Arabidopsis. Studies of some of these mutants have suggested that vascular tissue organization within the bundles and vascular pattern formation at the organ level are regulated by positional information.
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.
Marshall, Randolph S; Lazar, Ronald M
Vascular cognitive impairment has been traditionally defined by structural pathology – an accumulation of infarcts -- leading to progressive cognitive decline. Recent evidence, however, suggests that cognitive impairment may be independently mediated by hemodynamic dysfunction including global and hemispheral hypoperfusion and altered cerebral blood flow regulation. In this review we examine evidence for the contribution of hemodynamic impairment to cognitive dysfunction in the setting of large vessel disease, cardiac failure, and microvascular disease. If there is a hemodynamic component of vascular cognitive impairment, then treatments proposed to correct impaired vascular physiology may reasonably be expected to treat the cognitive dysfunction as well. PMID:21148438
Woo, Karen; Eldrup-Jorgensen, Jens; Hallett, John W; Davies, Mark G; Beck, Adam; Upchurch, Gilbert R; Weaver, Fred A; Cronenwett, Jack L
The Society for Vascular Surgery Vascular Quality Initiative (SVS VQI) is designed to improve the quality, safety, effectiveness, and cost of vascular health care. The SVS VQI is uniquely organized as a distributed network of regional quality improvement groups across the United States. The regional approach allows for the involvement of a variety of health care professionals, the pooling of available resources and expertise, and serves as a motivating factor for each participating institution. Regional quality group sizes, administrative structure, and meeting logistics vary according to geography and regional needs. This review describes the process of forming, growing, and maintaining a regional quality improvement group of the SVS VQI.
In this miniseries, we discuss the phenotype, origin, and specialized microenvironment (niche) of distinct populations of stem and progenitor cells that exhibit vascular potential. Their usefulness and effectiveness for clinical therapies are also described. We have learned a great deal about post...
Palmer, Theo D
Adult neurogenesis is mediated by immature neural precursors that divide within the residual germinal matrices of the brain. In the paper by in this issue of Neuron, the "cause and effect" of adult neurogenesis takes a major step forward with the description of a vascular signaling network that influences neuronal precursor migration and fate.
Duron, E; Hanon, Olivier
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.
Nieves, Bonnie J; D'Amore, Patricia A; Bryan, Brad A
Vascular endothelial growth factor (VEGF) is considered the master regulator of angiogenesis during growth and development, as well as in disease states such as cancer, diabetes, and macular degeneration. This review details our current understanding of VEGF signaling and discusses the benefits and unexpected side effects of promising anti-angiogenic therapeutics that are currently being used to inhibit neovacularization in tumors.
Lim, Shiang Y; Hernández, Damián; Dusting, Gregory J
The promise of stem cells to repair the heart after damage or heart attack has not been realized because most such cells are lost after transplantation. A new approach is to grow substantial viable pieces of cardiac tissue from human stem cells by cardiac tissue engineering. Such constructs must be fully vascularized and perfused to ensure the viability of clinically relevant volumes of tissue. This requires careful choice of cells, culture conditions, a biomaterial to act as scaffold, and crucial strategies for vascularization. Autologous stem cells with high plasticity, which would avoid the need for antirejection therapies after transplantation, are an attractive source of both cardiomyocytes and vascular cells. Most stem cells also have inherent paracrine activity, releasing cytoprotective factors and growth-promoting cytokines that can further stimulate tissue regeneration and neovascularization through recruitment of endogenous stem and progenitor cells. Current advances for growing vascularized and functional cardiac constructs with human stem cells are described, bringing us a step closer to the engineering of complex cardiac tissues such as pacemaker, conducting tissue, or contractile myocardial flaps ideal for transplantation. From studies in rats successful transplantation of thin constructs to the ventricle has been reported, but there remain further issues to resolve before larger human constructs will be available to test in the clinic.
Fischer, Lukas; Preis, Meir; Weisz, Anat; Koren, Belly; Lewis, Basil S; Flugelman, Moshe Y
Vascular gene therapy is the focus of multiple experimental and clinical research efforts. While several genes with therapeutic potential have been identified, the best method of gene delivery is unknown. Viral vectors have the capacity to transfer genes at high efficiency rates. Several viral-based vectors have been used in experimental vascular gene therapy for in vivo and ex vivo gene transfer. Adenoviral-based vectors are being used for the induction of angiogenesis in phase 1 and 2 clinical trials. In the present review, the characteristics of the ‘ideal’ viral vector are discussed and the major types of viral vectors used in vascular gene transfer are reviewed. Basic knowledge of the use of viral vectors for direct in vivo gene transfer (adenoviral-based vectors, etc) and for ex vivo gene transfer (retroviral-based vectors) is provided. New developments in the field of viral vectorology, such as pseudotyping of retroviral vectors and targeting of other viral vectors to a specific cell type, will enhance the more rapid transition of vascular gene therapy from the experimental arena to the clinical setting. PMID:19649233
Lin, Kai-Shun; Tsai, Chia-Ling; Tsai, Chih-Hsiangng; Sofka, Michal; Chen, Shih-Jen; Lin, Wei-Yang
Motivated by the goals of automatically extracting vessel segments and constructing retinal vascular trees with anatomical realism, this paper presents and analyses an algorithm that combines vessel segmentation and grouping of the extracted vessel segments. The proposed method aims to restore the topology of the vascular trees with anatomical realism for clinical studies and diagnosis of retinal vascular diseases, which manifest abnormalities in either venous and/or arterial vascular systems. Vessel segments are grouped using extended Kalman filter which takes into account continuities in curvature, width, and intensity changes at the bifurcation or crossover point. At a junction, the proposed method applies the minimum-cost matching algorithm to resolve the conflict in grouping due to error in tracing. The system was trained with 20 images from the DRIVE dataset, and tested using the remaining 20 images. The dataset contained a mixture of normal and pathological images. In addition, six pathological fluorescein angiogram sequences were also included in this study. The results were compared against the groundtruth images provided by a physician, achieving average success rates of 88.79% and 90.09%, respectively.
Fabris, Enrico; Kilic, Ismail Dogu; Caiazzo, Gianluca; Serdoz, Roberta; Foin, Nicolas; Sinagra, Gianfranco; Di Mario, Carlo
The mechanism of restenosis in bioresorbable vascular scaffold (BVS) may be different from that of metallic stents and it is still poorly investigated. Intravascular imaging techniques are useful tools for corroborating or excluding possible mechanisms of intra-scaffold restenosis. In these novel devices intravascular imaging should be systematically used for a better comprehension of the in-scaffold restenosis mechanism.
Rudström, H; Bergqvist, D; Ahlberg, J; Björck, M
The study aimed to estimate the incidence and causes of insurance claims (IC) after vascular surgery (VS) reported to the Swedish Medical Injury Insurance (SMII); and to validate the registration of complications in the National Vascular Registry (Swedvasc). The medical records of all IC in VS in Sweden reported to the SMII 2002-2007 were scrutinised and cross-referenced against Swedvasc. There were 193 claims after VS: varicose-veins (66), lower extremity (45), aortic (31) or carotid artery (21), access (19) or other VS (11). Frequent causes of claims were peripheral nerve injury (76), wound infection (22) and cranial nerve injury (15). More than half of the patients suffered permanent injuries, three died. As many as 55 (28%) received economic compensation (an average of 45% of all ICs in SMII). The highest frequency of compensated claims (1:650 yearly procedures) was for carotid artery surgery. Of the procedures, 187 were elective. Compared with the Swedvasc, claudication was a more common indication (28% vs. 12%). Nearly one-fifth (18%) were incorrectly registered in Swedvasc. The most common causes of insurance claims were peripheral nerve injuries and infections. Patients raising insurance claims after vascular surgery undergo acute procedures less frequently, and are correctly registered in the Swedvasc in 82% of cases. Copyright © 2011 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.
Brisset, Anne C.; Isakson, Brant E.
Abstract Cellular interaction in blood vessels is maintained by multiple communication pathways, including gap junctions. They consist of intercellular channels ensuring direct interaction between endothelial and smooth muscle cells and the synchronization of their behavior along the vascular wall. Gap-junction channels arise from the docking of two hemichannels or connexons, formed by the assembly of six connexins, and achieve direct cellular communication by allowing the transport of small metabolites, second messengers, and ions between two adjacent cells. Physiologic variations in connexin expression are observed along the vascular tree, with most common connexins being Cx37, Cx40, and Cx43. Changes in the level of expression of connexins have been correlated to the development of vascular disease, such as hypertension, atherosclerosis, or restenosis. Recent studies on connexin-deficient mice highlighted key roles of these communication pathways in the development of these pathologies and confirmed the need for targeted pharmacologic approaches for their prevention and treatment. The aim of this issue is to review the current knowledge on the implication of gap junctions in vascular function and most common cardiovascular diseases. Antioxid. Redox Signal. 11, 267–282. PMID:18834327
Chowriappa, Ashirwad; Seo, Yong; Salunke, Sarthak; Mokin, Maxim; Kan, Peter; Scott, Peter
We introduce a novel vascular skeleton extraction and decomposition technique for computer-assisted diagnosis and analysis. We start by addressing the problem of vascular decomposition as a cluster optimization problem and present a methodology for weighted convex approximations. Decomposed vessel structures are then grouped using the vessel skeleton, extracted using a Laplace-based operator. The method is validated using presegmented sections of vasculature archived for 98 aneurysms in 112 patients. We test first for vascular decomposition and next for vessel skeleton extraction. The proposed method produced promising results with an estimated 80.5% of the vessel sections correctly decomposed and 92.9% of the vessel sections having the correct number of skeletal branches, identified by a clinical radiological expert. Next, the method was validated on longitudinal study data from n = 4 subjects, where vascular skeleton extraction and decomposition was performed. Volumetric and surface area comparisons were made between expert segmented sections and the proposed approach on sections containing aneurysms. Results suggest that the method is able to detect changes in aneurysm volumes and surface areas close to that segmented by an expert.
Heimann, H; Jmor, F; Damato, B
The most common intraocular vascular tumours are choroidal haemangiomas, vasoproliferative tumours, and retinal haemangioblastomas. Rarer conditions include cavernous retinal angioma and arteriovenous malformations. Options for ablating the tumour include photodynamic therapy, argon laser photocoagulation, trans-scleral diathermy, cryotherapy, anti-angiogenic agents, plaque radiotherapy, and proton beam radiotherapy. Secondary effects are common and include retinal exudates, macular oedema, epiretinal membranes, retinal fibrosis, as well as serous and tractional retinal detachment, which are treated using standard methods (ie, intravitreal anti-angiogenic agents or steroids as well as vitreoretinal procedures, such as epiretinal membrane peeling and release of retinal traction). The detection, diagnosis, and monitoring of vascular tumours and their complications have improved considerably thanks to advances in imaging. These include spectral domain and enhanced depth imaging optical coherence tomography (SD-OCT and EDI-OCT, respectively), wide-angle photography and angiography as well as wide-angle fundus autofluorescence. Such novel imaging has provided new diagnostic clues and has profoundly influenced therapeutic strategies so that vascular tumours and secondary effects are now treated concurrently instead of sequentially, enhancing any opportunities for conserving vision and the eye. In this review, we describe how SD-OCT, EDI-OCT, autofluorescence, wide-angle photography and wide-angle angiography have facilitated the evaluation of eyes with the more common vascular tumours, that is, choroidal haemangioma, retinal vasoproliferative tumours, and retinal haemangioblastoma. PMID:23196648
Gahlaut, Nivriti; Suarez, Sandra; Uddin, Md Imam; Gordon, Andrew Y; Evans, Stephanie M; Jayagopal, Ashwath
Retinal vascular diseases, including diabetic retinopathy, neovascular age related macular degeneration, and retinal vein occlusion, are leading causes of blindness in the Western world. These diseases share several common disease mechanisms, including vascular endothelial growth factor (VEGF) signaling, hypoxia, and inflammation, which provide opportunities for common therapeutic strategies. Treatment of these diseases using laser therapy, anti-VEGF injections, and/or steroids has significantly improved clinical outcomes. However, these strategies do not address the underlying root causes of pathology, and may have deleterious side effects. Furthermore, many patients continue to progress toward legal blindness despite receiving regular therapy. Nanomedicine, the engineering of therapeutics at the 1-100 nm scale, is a promising approach for improving clinical management of retinal vascular diseases. Nanomedicine-based technologies have the potential to revolutionize the treatment of ophthalmology, through enabling sustained release of drugs over several months, reducing side effects due to specific targeting of dysfunctional cells, and interfacing with currently "undruggable" targets. We will discuss emerging nanomedicine-based applications for the treatment of complications associated with retinal vascular diseases, including angiogenesis and inflammation.
Barbacena, Pedro; Carvalho, Joana R; Franco, Claudio A
In this ESCHM 2016 conference talk report, we summarise two recently published original articles Franco et al. PLoS Biology 2015 and Franco et al. eLIFE 2016. The vascular network undergoes extensive vessel remodelling to become fully functional. Is it well established that blood flow is a main driver for vascular remodelling. It has also been proposed that vessel pruning is a central process within physiological vessel remodelling. However, despite its central function, the cellular and molecular mechanisms regulating vessel regression, and their interaction with blood flow patterns, remain largely unexplained. We investigated the cellular process governing developmental vascular remodelling in mouse and zebrafish. We established that polarised reorganization of endothelial cells is at the core of vessel regression, representing vessel anastomosis in reverse. Moreover, we established for the first time an axial polarity map for all endothelial cells together with an in silico method for the computation of the haemodynamic forces in the murine retinal vasculature. Using network-level analysis and microfluidics, we showed that endothelial non-canonical Wnt signalling regulates endothelial sensitivity to shear forces. Loss of Wnt5a/11 renders endothelial cells more sensitive to shear, resulting in axial polarisation at lower shear stress levels. Collectively our data suggest that non-canonical Wnt signalling stabilizes forming vascular networks by reducing endothelial shear sensitivity, thus keeping vessels open under low flow conditions that prevail in the primitive plexus.
Hashimoto, Takuya; Tsuneki, Masayuki; Foster, Trenton R.; Santana, Jeans M.; Bai, Hualong; Wang, Mo; Hu, Haidi; Hanisch, Jesse J.; Dardik, Alan
Vascular diseases span diverse pathology, but frequently arise from aberrant signaling attributed to specific membrane-associated molecules, particularly the Eph-ephrin family. Originally recognized as markers of embryonic vessel identity, Eph receptors and their membrane-associated ligands, ephrins, are now known to have a range of vital functions in vascular physiology. Interactions of Ephs with ephrins at cell-to-cell interfaces promote a variety of cellular responses such as repulsion, adhesion, attraction, and migration, and frequently occur during organ development, including vessel formation. Elaborate coordination of Eph- and ephrin-related signaling among different cell populations is required for proper formation of the embryonic vessel network. There is growing evidence supporting the idea that Eph and ephrin proteins also have postnatal interactions with a number of other membrane-associated signal transduction pathways, coordinating translation of environmental signals into cells. This article provides an overview of membrane-bound signaling mechanisms that define vascular identity in both the embryo and the adult, focusing on Eph- and ephrin-related signaling. We also discuss the role and clinical significance of this signaling system in normal organ development, neoplasms, and vascular pathologies. PMID:26992081
Johnson, Rebecca C; Leopold, Jane A; Loscalzo, Joseph
Once thought to result from passive precipitation of calcium and phosphate, it now appears that vascular calcification is a consequence of tightly regulated processes that culminate in organized extracellular matrix deposition by osteoblast-like cells. These cells may be derived from stem cells (circulating or within the vessel wall) or differentiation of existing cells, such as smooth muscle cells (SMCs) or pericytes. Several factors induce this transition, including bone morphogenetic proteins, oxidant stress, high phosphate levels, parathyroid hormone fragments, and vitamin D. Once the osteogenic phenotype is induced, cells gain a distinctive molecular fingerprint, marked by the transcription factor core binding factor alpha1. Alternatively, loss of inhibitors of mineralization, such as matrix gamma-carboxyglutamic acid Gla protein, fetuin, and osteopontin, also contribute to vascular calcification. The normal balance between promotion and inhibition of calcification becomes dysregulated in chronic kidney disease, diabetes mellitus, atherosclerosis, and as a consequence of aging. Once the physiological determinants of calcification are perturbed, calcification may occur at several sites in the cardiovascular system, including the intima and media of vessels and cardiac valves. Here, calcification may occur through overlapping yet distinct molecular mechanisms, each with different clinical ramifications. A variety of imaging techniques are available to visualize vascular calcification, including fluoroscopy, echocardiography, intravascular ultrasound, and electron beam computed tomography. These imaging modalities vary in sensitivity and specificity, as well as clinical application. Through greater understanding of both the mechanism and clinical consequences of vascular calcification, future therapeutic strategies may be more effectively designed and applied.
Yuan, Falei; Wang, Dong; Xu, Kang; Wang, Jixian; Zhang, Zhijun; Yang, Li; Yang, Guo-Yuan; Li, Song
The de-differentiation and proliferation of smooth muscle cells (SMCs) are widely accepted as the major contributor to vascular remodeling. However, recent studies indicate that vascular stem cells (VSCs) also play an important role, but their relative contribution remains to be elucidated. In this study, we used genetic lineage tracing approach to further investigate the contribution of SMCs and VSCs to neointimal thickening in response to endothelium denudation injury or artery ligation. In vitro and in vivo analysis of MYH11-cre/Rosa-loxP-RFP mouse artery showed that SMCs proliferated at a much slower rate than non-SMCs. Upon denudation or ligation injury, two distinct types of neointima were identified: Type-I neointimal cells mainly involved SMCs, while Type II mainly involved non-SMCs. Using Sox10-cre/Rosa-loxP-LacZ mice, we found that Sox10+ cells were one of the cell sources in neointima. In addition, lineage tracing using Tie2-cre/Rosa-LoxP-RFP showed that endothelial cells also contributed to the neointimal formation, but rarely transdifferentiated into mesenchymal lineages. These results provide a novel insight into the contribution of vascular cells to neointima formation, and have significant impact on the development of more effective therapies that target specific vascular cell types. PMID:28060852
Bordoli, Stefano J; Carsten, Christopher G; Cull, David L; Johnson, Brent L; Taylor, Spence M
Endovascular volume during vascular surgery training has increased profoundly over recent decades, providing heavy exposure to ionizing radiation. The study purpose was to examine the radiation safety training and practices of current vascular surgery trainees. An anonymous survey was distributed to all current U.S. trainees. Responses were compared according to the presence of formal radiation safety training and also the trainees' perception of their attendings' adherence to As Low As Reasonably Achievable (ALARA) strategies. The response rate was 14%. Forty-five percent had no formal radiation safety training, 74% were unaware of the radiation safety policy for pregnant females, 48% did not know their radiation safety officer's contact information, and 43% were unaware of the yearly acceptable levels of radiation exposure. Trained residents knew more basic radiation safety information, and more likely wore their dosimeter badges (P < .05). Trained residents found their radiation safety officer helpful in developing safety habits; untrained residents relied on other residents (P < .05). Trainees who felt their attendings consistently practiced ALARA strategies more likely practiced ALARA themselves (P < .05). The lack of formal radiation safety training in respondents may reflect an inadequate state of radiation safety education and practices among U.S. vascular surgery residents. Copyright © 2014 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.
Brennan, Kevin C; Beltrán-Parrazal, Luis; López-Valdés, Hector E; Theriot, Jeremy; Toga, Arthur W; Charles, Andrew C
Cortical spreading depression (CSD) is associated with significant vasodilatation and vasoconstriction, but the relationship between the cortical parenchymal and vascular phenomena remains poorly understood. We used optical intrinsic signal (OIS) imaging and electrophysiology to simultaneously examine the vascular and parenchymal changes that occur with CSD in anesthetized mice and rats. CSD was associated with a propagated multiphasic change in optical reflectance, with correlated negative DC shift in field potential. Dilatation of cortical surface arterioles propagated with a significantly greater intrinsic velocity than the parenchymal CSD wavefront measured by OIS and electrophysiology. Dilatation traveled in a circuitous pattern along individual arterioles, indicating specific vascular conduction as opposed to concentric propagation of a parenchymal signal. Arteriolar dilatation propagated into areas beyond the spread of parenchymal OIS and electrophysiological changes of CSD. Conversely, vasomotor activity could be experimentally dissociated from the parenchymal CSD wave. Frequent repetitive CSD evoked by continuous stimulation was associated with a reduced or absent arteriolar response despite preserved parenchymal OIS and electrophysiological changes. Similarly, dimethylsulfoxide at high concentrations (10%) inhibited arteriolar reactivity despite preserved parenchymal OIS and electrophysiological changes. These results suggest a mechanism, intrinsic to the vasculature, for propagation of vasodilatation associated with CSD. Distinct vascular conduction could be important for the pathogenesis of conditions that involve CSD, including migraine, stroke, and traumatic brain injury.
Novotný, K; Pádr, R; Landor, I; Sosna, A
Iatrogenic injuries to blood vessels in joint replacement surgery are rare events that occur as few per thousand. However, their sequelae are serious. The patient may either bleed to death, because vascular injury is not obvious and therefore difficult to diagnose, or lose the limb due to ischaemia. The highest risk of vascular injury is associated with repeat surgery and loosening of the acetabular component. We distinguish sharp and blunt force injuries. The former are caused by implants, sharp instruments, bone fragments or bone cement debris. The latter arise from stretching over a part of implanted material. Bleeding can be inapparent or apparent. Inapparent bleeding is difficult to diagnose and is recognized from the dynamics of blood losses. Haemodynamic instability or, in a worse case, even hypovolaemic shock may be the only signs of bleeding. Occlusion of an artery is manifested by limb ischaemia. The seriousness and progression of ischaemia depends on the rate of arterial occlusion, potential pathways for collateral circulation and the degree of atherosclerotic vascular disease. The patient with conduction anaesthesia does not feel pain and therefore the diagnosis must primarily be based on arterial pulsation in the limb and its skin colour. A pseudoaneurysm can develop due to a partially weakened vascular wall and its rupture is a life-threatening complication. Its presence is recognized as a pulsating mass in the groin. An arterio- venous fistula which arises from traumatic communication between the two vessels may lead to cardiac failure. The diagnosis is based on examination by sonography and digital subtraction angiography. The results of CT angiography and MR angiography are difficult to evaluate because of the presence of metal implants. In apparent bleeding it is sometimes difficult to locate the source. It is recommended to perform digital compression and gain access to the vessels from the extraperitoneal approach. When an expanding haematoma or
Vidi, Venkatesan D.; Matheny, Michael E.; Govindarajulu, Usha S.; Normand, Sharon-Lise T.; Robbins, Susan L.; Agarwal, Vikram V.; Bangalore, Sripal; Resnic, Frederic S.
Objectives To assess the frequency and predictors of vascular closure device (VCD) deployment failure, and its association with vascular complications of three commonly used VCDs. Background VCDs are commonly used following percutaneous coronary intervention (PCI) on the basis of studies demonstrating reduced time to ambulation, increased patient comfort, and possible reduction in vascular complications as compared to manual compression. However, limited data are available on the frequency and predictors of VCD failure, and the association of deployment failure with vascular complications. Methods From a de-identified dataset provided by Massachusetts Department of Health, 23,813 consecutive interventional coronary procedures that used either a collagen plug-based (n=18,533) or nitinol clip-based (n=2,284) or suture-based (n=2,996) VCD between 06/2005 and 12/2007 were identified. We defined VCD failure as unsuccessful deployment or failure to achieve immediate access site hemostasis. Results Among 23,813 procedures, VCD failed in 781 (3.3%) procedures (2.1% of collagen plug-based, 6.1% of suture-based, 9.5% of nitinol clip-based). Patients with VCD failure had excess risk of ‘any’ (7.7% versus 2.8%; P<0.001), major (3.3% versus 0.8%; P<0.001), or minor (5.8% versus 2.1%; P<0.001) vascular complications compared with successful VCD deployment. In a propensity-score adjusted analysis, when compared with collagen plug-based VCD (Reference OR =1.0), nitinol clip-based VCD had 2-fold increased risk (OR 2.0, 95% CI: 1.8–2.3, p<0.001) and suture-based VCD had 1.25-fold increased risk (OR 1.25, 95% CI: 1.2–1.3, p<0.001) for VCD failure. VCD failure was a significant predictor of subsequent vascular complications for both collagen plug-based VCD and nitinol clip-based VCD, but not for suture-based VCD. Conclusion VCD failure rates vary depending upon the types of VCD used and are associated with significantly higher vascular complications as compared to deployment
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
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
Varas-Díaz, Nelson; Neilands, Torsten B.; Guilamo-Ramos, Vincent; Cintrón Bou, Francheska N.
El estigma relacionado con el VIH/SIDA continúa siendo un obstáculo para la prevención primaria y secundaria del VIH. Las consecuencias para las personas que viven con la enfermedad han sido muy documentadas y continúan siendo una gran preocupación para las personas que proveen servicios de salud y para aquellas que investigan el tema. Estas consecuencias son preocupantes cuando el estigma emana de profesionales de la salud porque se puede limitar el acceso a los servicios. Uno de los principales obstáculos para la investigación del estigma relacionado con el VIH en Puerto Rico es la falta de instrumentos cuantitativos para evaluar las manifestaciones del estigma entre profesionales de la salud. El objetivo principal de este estudio fue desarrollar y probar las propiedades psicométricas de una escala sobre el estigma relacionado con el VIH/SIDA culturalmente apropiada para personas que proveen servicios de salud puertorriqueñas y desarrollar una versión corta de la escala que pudiera usarse en escenarios clínicos con tiempo limitado. El instrumento desarrollado estuvo basado en evidencia cualitativa recopilada entre profesionales y estudiantes de profesiones de la salud puertorriqueños/as (n=80) y administrado a una muestra de 421 profesionales de la salud en adiestramiento. La escala contenía 12 dimensiones del estigma relacionado con el VIH/SIDA. El análisis cuantitativo corroboró 11 de ellas, teniendo como resultado un instrumento con validez y confiabilidad satisfactoria. Estas dimensiones, a su vez, fueron subcomponentes de un factor de estigma general superior. PMID:20333258
Marsh, Donald J; Toma, Ildiko; Sosnovtseva, Olga V; Peti-Peterdi, Janos; Holstein-Rathlou, Niels-Henrik
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 synchronization. We tested this idea in tubular-vascular preparations from mice. Vascular smooth muscle cells were loaded with a fluorescent voltage-sensitive dye; fluorescence intensity was measured with confocal microscopy. Perfusion of the thick ascending limb activated TGF and depolarized afferent arteriolar smooth muscle cells. The depolarization spread to the cortical radial artery and other afferent arterioles and declined with distance from the perfused juxtaglomerular apparatus, consistent with electrotonic vascular signal propagation. With a mathematical model of two coupled nephrons, we estimated the conductance of nephron coupling by fitting simulated vessel diameters to experimental data. With this value, we simulated nephron pairs to test for synchronization. In single-nephron simulations, the frequency of the TGF oscillation varied with nephron length. Coupling nephrons of different lengths forced TGF frequencies of both pair members to converge to a common value. The myogenic oscillations also synchronized, and the synchronization between the TGF and the myogenic oscillations showed an increased stability against parameter perturbations. Electronic vascular signal propagation is a plausible mechanism for nephron synchronization. Coupling increased the stability of the various oscillations.
Popa, F; Grigorean, VT; Onose, G; Sandu, AM; Popescu, M; Burnei, G; Strambu, V; Sinescu, C
The aim of this article is to analyze the vascular dysfunctions occurring after spinal cord injury (SCI). Vascular dysfunctions are common complications of SCI. Cardiovascular disturbances are the leading causes of morbidity and mortality in both acute and chronic stages of SCI. Neuroanatomy and physiology of autonomic nervous system, sympathetic and parasympathetic, is reviewed. SCI implies disruption of descendent pathways from central centers to spinal sympathetic neurons, originating in intermediolateral nuclei of T1–L2 cord segments. Loss of supraspinal control over sympathetic nervous system results in reduced overall sympathetic activity below the level of injury and unopposed parasympathetic outflow through intact vagal nerve. SCI associates significant vascular dysfunction. Spinal shock occurs during the acute phase following SCI and it is a transitory suspension of function and reflexes below the level of the injury. Neurogenic shock, part of spinal shock, consists of severe arterial hypotension and bradycardia. Autonomic dysreflexia appears during the chronic phase, after spinal shock resolution, and it is a life–threatening syndrome of massive imbalanced reflex sympathetic discharge occurring in patients with SCI above the splanchnic sympathetic outflow (T5–T6). Arterial hypotension with orthostatic hypotension occurs in both acute and chronic phases. The etiology is multifactorial. We described a few factors influencing the orthostatic hypotension occurrence in SCI: sympathetic nervous system dysfunction, low plasma catecholamine levels, rennin–angiotensin–aldosterone activity, peripheral alpha–adrenoceptor hyperresponsiveness, impaired function of baroreceptors, hyponatremia and low plasmatic volume, cardiovascular deconditioning, morphologic changes in sympathetic neurons, plasticity within spinal circuits, and motor deficit leading to loss of skeletal muscle pumping activity. Additional associated cardiovascular concerns in SCI, such as
Unnikrishnan, Madathipat; Viswanathan, Sidharth; Balasubramaniam, K.; Muraleedharan, C.V.; Lal, Arthur Vijayan; Mohanan, P.V.; Mohanty, Meera; Kapilamoorthy, Tirur Raman
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. PMID:27748302
Kota, Sunil Kumar; Kota, Siva Krishna; Meher, Lalit Kumar; Jammula, Sruti; Panda, Sandip; Modi, Kirtikumar D.
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. PMID:23226643
Kota, Sunil Kumar; Kota, Siva Krishna; Meher, Lalit Kumar; Jammula, Sruti; Panda, Sandip; Modi, Kirtikumar D
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. 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. 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. 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.
Popa, Constantin; Popa, Florian; Grigorean, Valentin Titus; Onose, Gelu; Sandu, Aurelia Mihaela; Popescu, Mihai; Burnei, Gheorghe; Strambu, Victor; Sinescu, Crina
The aim of this article is to analyze the vascular dysfunctions occurring after spinal cord injury (SCI). Vascular dysfunctions are common complications of SCI. Cardiovascular disturbances are the leading causes of morbidity and mortality in both acute and chronic stages of SCI. Neuroanatomy and physiology of autonomic nervous system, sympathetic and parasympathetic, is reviewed. SCI implies disruption of descendent pathways from central centers to spinal sympathetic neurons, originating in intermediolateral nuclei of T1-L2 cord segments. Loss of supraspinal control over sympathetic nervous system results in reduced overall sympathetic activity below the level of injury and unopposed parasympathetic outflow through intact vagal nerve. SCI associates significant vascular dysfunction. Spinal shock occurs during the acute phase following SCI and it is a transitory suspension of function and reflexes below the level of the injury. Neurogenic shock, part of spinal shock, consists of severe arterial hypotension and bradycardia. Autonomic dysreflexia appears during the chronic phase, after spinal shock resolution, and it is a life-threatening syndrome of massive imbalanced reflex sympathetic discharge occurring in patients with SCI above the splanchnic sympathetic outflow (T5-T6). Arterial hypotension with orthostatic hypotension occurs in both acute and chronic phases. The etiology is multifactorial. We described a few factors influencing the orthostatic hypotension occurrence in SCI: sympathetic nervous system dysfunction, low plasma catecholamine levels, rennin-angiotensin-aldosterone activity, peripheral alpha-adrenoceptor hyperresponsiveness, impaired function of baroreceptors, hyponatremia and low plasmatic volume, cardiovascular deconditioning, morphologic changes in sympathetic neurons, plasticity within spinal circuits, and motor deficit leading to loss of skeletal muscle pumping activity. Additional associated cardiovascular concerns in SCI, such as deep vein
Wang, Tianmiao; Zhang, Dapeng; Da, Liu
Conventional vascular interventional surgery (VIS) is manually performed under fluoroscopic guidance, requiring lead protection for the surgeons. A remote-control vascular interventional surgery robot (VISR) which can remotely, safely and precisely perform VIS would have clear advantages. Our robot adopts a master-slave structure. The surgeon sits at the master site, sending controlling instructions to the robot fixed at the slave site, then the robot translates these instructions into catheter motion. The robotic mechanism consists of a supporting manipulator and a catheter navigator; the former adjusts the robot's spatial position, while the latter controls the translation and rotation of the catheter. A 3D vascular model is reconstructed so that the surgeon can perform surgical planning easily. In addition, the tactile force between catheter tip and blood vessel is measured, which prevents the surgeon damaging delicate vessels. In glass model and animal experiments, the surgeon remotely controlled VISR, which inserted a catheter into predefined targets, and the robotic surgery time was measured. The robot was initially tested on a transparent glass vascular model. Under robotic manipulation, the catheter can enter an arbitrary branch of the vascular model and catheter motion can meet the requirements of clinical VIS. Then robotic surgery was performed successfully in an adult dog. Surgery time to access each of the five targets, viz. renal artery, left atrium, right atrium, left ventricle and right ventricle, was measured. Compared with conventional manual surgery, robotic surgery time is a little longer. The experiments show the feasibility and safety of the VISR to facilitate navigation, position precisely and control catheters to specific regions. The VISR system offers surgeon radiation safety and minimizes surgeon-based error. (c) 2010 John Wiley & Sons, Ltd.
Scarmeas, Nikolaos; Stern, Yaakov; Mayeux, Richard; Luchsinger, Jose A.
Objectives To examine the association between the Mediterranean diet (MeDi) and Alzheimer disease (AD) in a different AD population and to investigate possible mediation by vascular pathways. Design, Setting, Patients, and Main Outcome Measures A case-control study nested within a community-based cohort in New York, NY. Adherence to the MeDi (0- to 9-point scale with higher scores indicating higher adherence) was the main predictor of AD status (194 patients with AD vs 1790 nondemented subjects) in logistic regression models that were adjusted for cohort, age, sex, ethnicity, education, apolipoprotein E genotype, caloric intake, smoking, medical comorbidity index, and body mass index (calculated as weight in kilograms divided by height in meters squared). We investigated whether there was attenuation of the association between MeDi and AD when vascular variables (stroke, diabetes mellitus, hypertension, heart disease, lipid levels) were simultaneously introduced in the models (which would constitute evidence of mediation). Results Higher adherence to the MeDi was associated with lower risk for AD (odds ratio, 0.76; 95% confidence interval, 0.67–0.87; P<.001). Compared with subjects in the lowest MeDi tertile, subjects in the middle MeDi tertile had an odds ratio of 0.47 (95% confidence interval, 0.29–0.76) and those at the highest tertile an odds ratio of 0.32 (95% confidence interval, 0.17–0.59) for AD (P for trend <.001). Introduction of the vascular variables in the model did not change the magnitude of the association. Conclusions We note once more that higher adherence to the MeDi is associated with a reduced risk for AD. The association does not seem to be mediated by vascular comorbidity. This could be the result of either other biological mechanisms (oxidative or inflammatory) being implicated or measurement error of the vascular variables. PMID:17030648
Delaying the onset of dementia by just a few years could have a major impact on the prevalence of the disease at the population level. Vascular risk factors are modifiable and may offer an important opportunity for preventive approaches. Several studies have shown that diabetes, hypertension, obesity, and smoking are associated with an increased risk of cognitive decline and dementia, but other groups have not observed such a relation. Positive associations were observed mainly in studies where risk factors were assessed in midlife, suggesting that age is an important modulator in the relation between vascular risk factors and cognition. The population attributable risk of dementia is particularly high for hypertension. Associations of vascular risk factors with cognitive decline and dementia are probably mediated largely by cerebrovascular disease, including both stroke and covert vascular brain injury, which can have additive or synergistic effects with coexisting neurodegenerative lesions. To date, randomized trials have not convincingly demonstrated that treating vascular risk factors is associated with a reduction in cognitive decline or dementia risk. Of eight randomized trials testing the effect of antihypertensive agents on dementia risk, only one was positive, and another in a subgroup of individuals with recurrent stroke. In most trials, cognition and dementia were secondary outcomes, follow-up was short and treatment was initiated at an older age. No effect on cognitive decline or dementia could be demonstrated for statins and intensive glycemic control. Future areas of investigation could include differential class effects of antihypertensive drugs on cognitive outcomes and identification of high risk individuals as target population for clinical trials initiated in midlife. Copyright © 2013. Published by Elsevier Masson SAS.
Scarmeas, Nikolaos; Stern, Yaakov; Mayeux, Richard; Luchsinger, Jose A
To examine the association between the Mediterranean diet (MeDi) and Alzheimer disease (AD) in a different AD population and to investigate possible mediation by vascular pathways. Design, Setting, Patients, and A case-control study nested within a community-based cohort in New York, NY. Adherence to the MeDi (0- to 9-point scale with higher scores indicating higher adherence) was the main predictor of AD status (194 patients with AD vs 1790 nondemented subjects) in logistic regression models that were adjusted for cohort, age, sex, ethnicity, education, apolipoprotein E genotype, caloric intake, smoking, medical comorbidity index, and body mass index (calculated as weight in kilograms divided by height in meters squared). We investigated whether there was attenuation of the association between MeDi and AD when vascular variables (stroke, diabetes mellitus, hypertension, heart disease, lipid levels) were simultaneously introduced in the models (which would constitute evidence of mediation). Higher adherence to the MeDi was associated with lower risk for AD (odds ratio, 0.76; 95% confidence interval, 0.67-0.87; P<.001). Compared with subjects in the lowest MeDi tertile, subjects in the middle MeDi tertile had an odds ratio of 0.47 (95% confidence interval, 0.29-0.76) and those at the highest tertile an odds ratio of 0.32 (95% confidence interval, 0.17-0.59) for AD (P for trend <.001). Introduction of the vascular variables in the model did not change the magnitude of the association. We note once more that higher adherence to the MeDi is associated with a reduced risk for AD. The association does not seem to be mediated by vascular comorbidity. This could be the result of either other biological mechanisms (oxidative or inflammatory) being implicated or measurement error of the vascular variables.
Hernandez-Boussard, Tina; McDonald, Kathryn; Morton, John; Dalman, Ron L; Bech, Fritz R
Background Patient safety is a national priority. Patient Safety Indicators (PSIs) monitor potential adverse events during hospital stays. Surgical specialty PSI benchmarks do not exist, which are needed to account for differences in the range of procedures performed, reasons for the procedure, and differences in patient characteristics. A comprehensive profile of adverse events in vascular surgery was created. Study Design The Nationwide Inpatient Sample was queried for 8 vascular procedures using ICD-9-CM codes from 2005–2009. Factors associated with PSI development were evaluated in univariate and multivariate analyses. Results A total of 1,412,703 patients underwent a vascular procedure and 5.2% developed a PSI. PSIs were more frequent in female, non-white patients with public payers (p<.01). Patients at mid and low volume hospitals had greater odds of developing a PSI (Odds Ratio [OR], 1.17; 95% Confidence Interval [CI], 1.10–1.23 and OR, 1.69; CI, 1.53–1.87). Amputations had highest PSI risk-adjusted rate (RAR) and carotid endarterectomy and endovascular abdominal aortic aneurysm (AAA) repair had lower RAR (p<.0001). PSI RAR increased linearly by severity of patient indication: claudicants (OR, 0.40, CI, 0.35–0.46), rest pain patients (OR, 0.78, CI 0.69–0.90), ulcer (OR: 1.20, CI: 1.07–1.34) and gangrene patients (OR:1.85, CI: 1.66–2.06). Conclusions Patient safety events in vascular surgery were high and varied by procedure, with amputations and open AAA having substantially more potential adverse events. PSIs were associated with black race, public payer, and procedure indication. It is important to note the overall higher rates of PSIs occurring in vascular patients and appropriately adjust benchmarks for this surgical specialty. PMID:22425449
Brown, Kate V; Ramasamy, Arul; Tai, Nigel; MacLeod, Judith; Midwinter, Mark; Clasper, Jon C
The extremities remain the most common sites of wounding in conflict, are associated with a significant incidence of vascular trauma, and have a high complication rate (infection, secondary amputation, and graft thrombosis). The purpose of this study was to study the complication rate after extremity vascular injury. In particular, the aim was to analyze whether this was influenced by the presence or absence of a bony injury. A prospectively maintained trauma registry was retrospectively reviewed for all UK military casualties with extremity injuries (Abbreviated Injury Score >1) December 8, 2003 to May 12, 2008. Demographics and the details of their vascular injuries, management, and outcome were documented using the trauma audit and medical notes. Thirty-four patients (34%)--37 limbs (30%)--had sustained a total of 38 vascular injuries. Twenty-eight limbs (22.6%) had an associated fracture, 9 (7.3%) did not. Twenty-nine limbs (23.4%) required immediate revascularization to preserve their limb: 16 limbs (13%) underwent an initial Damage Control procedure, and 13 limbs (10.5%) underwent Definitive Surgery. Overall, there were 25 limbs (20.2%) with complications. Twenty-two were in the 28 limbs with open fractures, 3 were in the 9 limbs without a fracture (p < 0.05). There was no significant difference in the complication rate with respect to upper versus lower limb and damage control versus definitive surgery. We have demonstrated that prognosis is worse after military vascular trauma if there is an associated fracture, probably due to higher energy transfer and greater tissue damage.
de Jong, F.J.; Schrijvers, E.M.C.; Ikram, M.K.; Koudstaal, P.J.; de Jong, P.T.V.M.; Hofman, A.; Vingerling, J.R.
Background: Retinal vessels provide a unique opportunity to study both systemic and cerebrovascular disease. Smaller retinal arteriolar calibers are strongly related to hypertension, whereas larger retinal venular calibers are more related to inflammation, cerebral hypoperfusion, and cerebrovascular disease. Whether retinal vessel calibers are related to dementia remains unclear. Methods: We investigated whether retinal arteriolar and venular calibers are associated with risk of dementia, and its subtypes Alzheimer disease (AD) and vascular dementia, in the prospective population-based Rotterdam Study. Digitized retinal images were available in 5,553 participants aged 55 years or over and dementia-free at baseline (1990–1993). Participants were re-examined in 1993–1994, 1997–1999, and 2002–2004 and were continuously monitored for development of dementia. Results: During a mean follow-up of 11.6 years, 655 participants developed dementia. AD was diagnosed in 519 and vascular dementia in 73 participants. Larger venular calibers were associated with an increased risk of dementia, in particular vascular dementia (age- and sex-adjusted hazard ratio per SD increase: 1.31; 95% confidence interval 1.06–1.64), but not AD. The association remained significant after adjustment for stroke and cardiovascular risk factors. Smaller arteriolar calibers were also associated with an increased risk of vascular dementia, yet only when adjusted for venular calibers. Conclusions: Retinal venular widening is associated with an increased risk of vascular dementia. Our findings are in line with previous observations in stroke and cerebral small-vessel disease and suggest that the association between larger retinal venular calibers and dementia may reflect cerebral hypoperfusion and subsequent ischemia. PMID:21288987
J., Binu Tharakan; Whaley, Greg; Hunter, Felicia A.; Smythe, W. Roy; Childs, Ed W.
Recent studies from our laboratory demonstrated the involvement of endothelial cell reactive oxygen species (ROS) formation and activation of apoptotic signaling in vascular hyperpermeability following hemorrhagic shock (HS). The objective of this study was to determine if (-)-deprenyl, an antioxidant with anti-apoptotic properties would attenuate HS-induced vascular hyperpermeability. In rats, HS was induced by withdrawing blood to reduce the MAP to 40 mmHg for 60 minutes followed by resuscitation for 60 minutes. To study hyperpermeability, the rats were injected with FITC-albumin (50 mg/kg) and the changes in integrated optical intensity of the mesenteric post-capillary venules were obtained intra and extra vascularly utilizing intravital microscopy. Mitochondrial ROS formation and mitochondrial transmembrane potential (ΔΨm) were studied using dihydrorhodamine 123 and JC-1 respectively. Mitochondrial release of cytochrome c was determined using ELISA and caspase-3 activity by a fluorometric assay. Parallel studies were performed in rat lung microvascular endothelial cells (RLMEC) utilizing pro-apoptotic BAK as inducer of hyperpermeability. Hemorrhagic shock induced vascular hyperpermeability, mitochondrial ROS formation, decrease in ΔΨm, release of cytochrome c and caspase-3 activation (p < 0.05). (-)-Deprenyl (0.15 mg/Kg) attenuated all these effects (p < 0.05). Similarly in RLMEC, (-)-deprenyl attenuated BAK peptide induced monolayer hyperpermeability (p < 0.05), ROS formation, decrease in ΔΨm, cytochrome c release (p < 0.05) and activation of caspase-3 (p < 0.05). The protective effects of (-)-deprenyl on vascular barrier functions may be due to its protective effects on ΔΨm thereby preventing mitochondrial release of cytochrome c and caspase-3 mediated disruption of endothelial adherens junctions. PMID:19373132
Vascular access dysfunction is a major cause of morbidity and mortality in hemodialysis patients. The most common cause of vascular access dysfunction is venous stenosis from neointimal hyperplasia within the perianastomotic region of an arteriovenous fistula and at the graft-vein anastomosis of an arteriovenous graft. There have been few, if any, effective treatments for vascular access dysfunction because of the limited understanding of the pathophysiology of venous neointimal hyperplasia formation. This review will (1) describe the histopathologic features of hemodialysis access stenosis; (2) discuss novel concepts in the pathogenesis of neointimal hyperplasia development, focusing on downstream vascular biology; (3) highlight future novel therapies for treating downstream biology; and (4) discuss future research areas to improve our understanding of downstream biology and neointimal hyperplasia development.
Summary Vascular access dysfunction is a major cause of morbidity and mortality in hemodialysis patients. The most common cause of vascular access dysfunction is venous stenosis from neointimal hyperplasia within the perianastomotic region of an arteriovenous fistula and at the graft-vein anastomosis of an arteriovenous graft. There have been few, if any, effective treatments for vascular access dysfunction because of the limited understanding of the pathophysiology of venous neointimal hyperplasia formation. This review will (1) describe the histopathologic features of hemodialysis access stenosis; (2) discuss novel concepts in the pathogenesis of neointimal hyperplasia development, focusing on downstream vascular biology; (3) highlight future novel therapies for treating downstream biology; and (4) discuss future research areas to improve our understanding of downstream biology and neointimal hyperplasia development. PMID:23990166
Khalil, Raouf A
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.
Khalil, Raouf A.
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. PMID:24099797
Raffetto, Joseph D.; Khalil, Raouf A.
Matrix metalloproteinases (MMPs) are a family of proteolytic enzymes that degrade various components of the extracellular matrix (ECM). Members of the MMP family include collagenases, gelatinases, stromelysins, matrilysins and membrane-type MMPs. ProMMPs are cleaved into active forms that promote degradation of ECM proteins. Also, recent evidence suggests direct or indirect effects of MMPs on ion channels in the endothelium and vascular smooth muscle, and on other mechanisms of vascular relaxation/contraction. Endogenous tissue inhibitors of metalloproteinases (TIMPs) reduce excessive proteolytic ECM degradation by MMPs. The balance between MMPs and TIMPs plays a major role in vascular remodeling, angiogenesis, and the uterine and systemic vasodilation during normal pregnancy. An imbalance in the MMPs/TIMPs activity ratio may underlie the pathogenesis of vascular diseases such as abdominal aortic aneurysm, varicose veins, hypertension and preeclampsia. Downregulation of MMPs using genetic manipulations of endogenous TIMPs, or synthetic pharmacological inhibitors such as BB-94 (Batimastat) and doxycycline, and Ro-28-2653, a more specific inhibitor of gelatinases and membrane type 1-MMP, could be beneficial in reducing the MMP-mediated vascular dysfunction and the progressive vessel wall damage associated with vascular disease. PMID:17678629
Ellis, Michael J; Armstrong, Derek; Dirks, Peter B
The management of large and giant arteriovenous malformations (AVMs) in patients presenting with nonhemorrhagic neurological deficits secondary to vascular steal phenomenon is challenging and controversial. In many cases, large AVMs cannot be completely excised or cured, leaving patients with residual or partially treated AVMs, the natural history of which is unknown. Additionally, large, diffuse vascular malformations with multiple, small feeders, slow flow, or so-called cerebral proliferative angiopathy represent a related but distinct clinical and angiographic entity that may require a different therapeutic approach than traditional brain AVMs. The current management of children with other conditions of chronic cerebral hypoperfusion, such as moyamoya disease, involves consideration of surgical revascularization to enhance blood flow to the compromised hemisphere. Here, the authors present the case of a young child with a large thalamic vascular malformation who presented with clinical and radiological features of vascular steal and ischemia. In an effort to augment flow to the hypoperfused brain and protect against future ischemia, the authors treated the child with unilateral pial synangiosis. At 12 months, postoperative angiography demonstrated robust neovascularization, and the child has not sustained any further ischemic events. The authors discuss concept of vascular malformation-related hypoperfusion and the utility of indirect revascularization for inoperable vascular malformations presenting with ischemic symptoms.
Luo, Jiesi; Qin, Lingfeng; Kural, Mehmet H; Schwan, Jonas; Li, Xia; Bartulos, Oscar; Cong, Xiao-Qiang; Ren, Yongming; Gui, Liqiong; Li, Guangxin; Ellis, Matthew W; Li, Peining; Kotton, Darrell N; Dardik, Alan; Pober, Jordan S; Tellides, George; Rolle, Marsha; Campbell, Stuart; Hawley, Robert J; Sachs, David H; Niklason, Laura E; Qyang, Yibing
Development of autologous tissue-engineered vascular constructs using vascular smooth muscle cells (VSMCs) derived from human induced pluripotent stem cells (iPSCs) holds great potential in treating patients with vascular disease. However, preclinical, large animal iPSC-based cellular and tissue models are required to evaluate safety and efficacy prior to clinical application. Herein, swine iPSC (siPSC) lines were established by introducing doxycycline-inducible reprogramming factors into fetal fibroblasts from a line of inbred Massachusetts General Hospital miniature swine that accept tissue and organ transplants without immunosuppression within the line. Highly enriched, functional VSMCs were derived from siPSCs based on addition of ascorbic acid and inactivation of reprogramming factor via doxycycline withdrawal. Moreover, siPSC-VSMCs seeded onto biodegradable polyglycolic acid (PGA) scaffolds readily formed vascular tissues, which were implanted subcutaneously into immunodeficient mice and showed further maturation revealed by expression of the mature VSMC marker, smooth muscle myosin heavy chain. Finally, using a robust cellular self-assembly approach, we developed 3D scaffold-free tissue rings from siPSC-VSMCs that showed comparable mechanical properties and contractile function to those developed from swine primary VSMCs. These engineered vascular constructs, prepared from doxycycline-inducible inbred siPSCs, offer new opportunities for preclinical investigation of autologous human iPSC-based vascular tissues for patient treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.
Hasnain, Mehrul; Vieweg, W Victor R
The contribution of vascular risk factors to Alzheimer-vascular spectrum dementias is increasingly being recognized. We provide an overview of recent literature on this subject. Overweight and obesity as well as underweight during midlife predict cognitive decline and dementia later in life. Hypertension during midlife is also associated with dementia later in life and the association is stronger for untreated hypertension. Calcium channel blockers, angiotensin converting enzyme inhibitors, and angiotensin-1 receptor-blockers may be particularly beneficial in diminishing the risk of dementia associated with hypertension. Studies have fairly consistently shown that type 2 diabetes is a risk factor for dementia. Episodes of hypoglycemia add to this risk. Regular physical exercise during any point in the lifespan protects against cognitive decline and dementia. Most benefit is realized with physical exercise during early and midlife. Dyslipidemia also increases the risk of dementia but the findings are less consistent. Findings on the possible benefit of lipid-lowering agents (statins) are conflicting. Earlier studies identified smoking as protective of dementia but recent better designed studies have consistently shown that smoking increases the risk of dementia. The association of vascular risk factors with dementia is more robust for vascular dementia than Alzheimer's disease. Heterogeneity of studies and lack of trials specifically designed to assess cognition as an endpoint make firm conclusions difficult. But considering the expected global burden of dementia and projected attributable risk of vascular risk factors to it, there is sufficient evidence to promote vascular risk factor reduction strategies as dementia prevention interventions.
O’Brien, Haley D.; Williams, Susan H.
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. PMID:24835249
Kurozumi, Akira; Okada, Yosuke; Nakano, Kazuhisa; Tanaka, Yoshiya
In Japan, the number of diabetes mellitus and chronic kidney disease patients is increasing yearly. Vascular calcification is prevailing in patients suffering from diabetes mellitus and/or chronic kidney disease, and carries a poor prognosis. However, the effective treatment for suppressing the progression of vascular calcification has not been established. On the other hand, treatment of osteoporosis has advanced dramatically as the details of the mechanism become clearer. Bisphosphonates, which are inhibitors of bone resorption that are widely used to treat osteoporosis, also inhibit cholesterol biosynthesis, differentiation of macrophage to foam cell, differentiation of smooth muscle cells to osteoblast-like cells in certain stimuli during calcification processes of vessels. These findings extend the link between bone remodeling and vascular calcification, opening perspectives toward novel therapeutic strategies. We herein review recent findings about effectiveness of bisphosphonates for vascular calcification with our data. Here we will review recent advances in the researches of treatment of vascular calcification and present our findings that the bisphosphonate is useful in prevention of vascular calcification.
Eguare, E; Tierney, S; Maher, R; Creamer, M; Grace, P; Cronin, C J; Burke, P
The development of regional dialysis units and the expanding indications for dialysis has led to increased demand for vascular access surgery. Consequently, the provision and maintenance of access, and the management of related complications has created a considerable burden on vascular surgical units in hospitals providing renal replacement therapy (RRT). The objectives of our study were to review our experience with a variety of vascular access modalities for haemodialysis and to quantify the associated surgical workload. We reviewed our experience in a consecutive group of dialysis patients who had access surgery for RRT in a regional hospital setting. Between January 1995 and January 2000, 69 patients entered the long-term dialysis programme in the Mid-Western region (population = 320,000). Of the 158 procedures performed, 138 (87%) were for access creation, and 20 (13%) related to access revision procedures. Twenty patients (29%) developed a total of 30 access related complications. Vascular access procedures accounted for 10% of the vascular surgical workload (1598 procedures) in the five-year period. Vascular access is an important part of the haemodialysis services and surgical expertise should be available at local level to cope with likely demand.
O'Brien, Haley D; Williams, Susan H
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.
Basile, David P
Acute kidney injury following folate administration is characterized by a vascular remodeling that is initially proliferative but subsequently results in vascular endothelial loss. Interventions directed toward promoting endothelial growth may preserve vascular structure and therefore renal function. However, angiopoietin-1 therapy in the setting of folate-induced acute kidney injury resulted in an expanded fibrotic response despite apparent preservation of the vasculature, indicating that renal repair responses are complex and vascular-directed therapies should be approached with caution.
Ge, Benjamin H.; Copelan, Alexander; Scola, Dominic; Watts, Micah M.
Vascular interventional radiology procedures are relatively safe compared with analogous surgical procedures, with overall major complication rates of less than 1%. However, major vascular injuries resulting from these procedures may lead to significant morbidity and mortality. This review will discuss the etiology, clinical presentation, diagnosis, and management of vascular complications related to percutaneous vascular interventions. Early recognition of these complications and familiarity with treatment options are essential skills for the interventional radiologist. PMID:26038619
Creager, Mark A; Hiatt, William R; Hirsch, Alan T; Olin, Jeffrey W; Jaff, Michael R; Cooke, John P; Rooke, Thom; Beckman, Joshua A; Froehlich, James B
The Society for Vascular Medicine was founded in 1989. During the subsequent 25 years, the Society has grown to approximately 500 members and has achieved international recognition while making important contributions to vascular disease education, clinical vascular medicine and biology research, and patient care. In celebration of the Society's 25th anniversary, its past and current presidents reflect on the Society's history, challenges, and achievements, and emphasize the vital role of the SVM in the discipline of vascular medicine.
underway and we have developed the surveillance program design and identified Service Members who incurred vascular injury. To date, four research nurse ...Current study staff consists of a program manager and four research nurses . The GWOT 2 Wartime Vascular Injury Study is an ongoing effort; therefore, the... Nurse , 2-4 April 2014, poster presentation o Vascular discharge education and follow-up care subsequent to wartime vascular trauma; Presented in San
Dias, Márcio-Américo; Dias, Pedro-de Souza; Martínez-Martínez, Marisol; Sena-Filho, Marcondes; de Almeida, Oslei-Paes
Vascular lesions have been classified in two broad categories, hemangiomas and malformations. Encapsulated vascular lesions have not been reported in the oral cavity, but they were described in other sites, mainly in the orbit. Herein, we present a case of an oral encapsulated vascular lesion located in the right buccal mucosa of a 69-year-old male, including histological and immunohistochemical description and a literature review. Key words:Buccal mucosa, hemangioma, vascular malformation, oral cavity. PMID:26855712
Asmussen, Sven; Salter, Michael; Prough, Donald S; Kramer, George C; Svensen, Christer; Sheffield-Moore, Melinda; Kinsky, Michael P
The primary goal of fluid therapy is to maintain fluid homeostasis. Commonly used isotonic crystalloids are only marginally effective and contribute to fluid excess syndrome. In patients with decreased cardiovascular reserve, fluid therapy alone is not sufficient to maintain end-organ perfusion. Therefore, inotropes or vasoactive drugs are used to supplement fluid infusion. Recent animal data suggest that coinfusion of adrenergic agents modulate the distribution of fluid between the vascular and extravascular/interstitial compartments after a fluid bolus. We sought to determine if this effect would translate in humans by coadministering a β-adrenergic agonist with fluid. Nine healthy volunteers (aged 21-50 years) were randomly paired and received either a continuous isoproterenol infusion (ISO: 0.05 μg/kg per minute) or 0.9% saline (control [CON]) 30min prior to a 25 mL/kg 0.9% NaCl fluid bolus. Hemodynamics, ventricular volume and function, and microcirculatory determinants (capillary filtration coefficient and oncotic pressure) were measured. Vascular and extravascular volume and fluid balance were determined. Compared with CON, ISO significantly increased heart rate (CON: 64.2 ± 4.1 beats/min vs. ISO: 97.4 ± 5.7 beats/min) and cardiac output (CON: 4.4 ± 0.7 L/min vs. ISO: 10.2 ± 0.9) before fluid bolus. Isoproterenol significantly increased urinary output (ISO: 10.86 ± 1.95 vs. control: 6.53 ± 1.45 mL/kg) and reduced extravascular volume (7.98 ± 2.0 vs. 14.15 ± 1.1mL/kg). Isoproterenol prevented an increase in capillary filtration coefficient (1.74 ± 0.4 vs. 3.21 ± 0.4 mL/min per mmHg · 10). Isoproterenol, a nonselective β-adrenergic agonist, augments vascular volume expansion and eliminates extravascular volume via enhanced diuresis, which may in part be due to enhanced endothelial barrier function.
Andrew Groover; Rachel Spicer
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...
Huttala, Outi; Vuorenpää, Hanna; Toimela, Tarja; Uotila, Jukka; Kuokkanen, Hannu; Ylikomi, Timo; Sarkanen, Jertta-Riina; Heinonen, Tuula
The formation of blood vessels is a vital process in embryonic development and in normal physiology. Current vascular modelling is mainly based on animal biology leading to species-to-species variation when extrapolating the results to humans. Although there are a few human cell based vascular models available these assays are insufficiently characterized in terms of culture conditions and developmental stage of vascular structures. Therefore, well characterized vascular models with human relevance are needed for basic research, embryotoxicity testing, development of therapeutic strategies and for tissue engineering. We have previously shown that the in vitro vascular model based on co-culture of human adipose stromal cells (hASC) and human umbilical vein endothelial cells (HUVEC) is able to induce an extensive vascular-like network with high reproducibility. In this work we developed a defined serum-free vascular stimulation medium (VSM) and performed further characterization in terms of cell identity, maturation and structure to obtain a thoroughly characterized in vitro vascular model to replace or reduce corresponding animal experiments. The results showed that the novel vascular stimulation medium induced intact and evenly distributed vascular-like network with morphology of mature vessels. Electron microscopic analysis assured the three-dimensional microstructure of the network containing lumen. Additionally, elevated expressions of the main human angiogenesis-related genes were detected. In conclusion, with the new defined medium the vascular model can be utilized as a characterized test system for chemical testing as well as in creating vascularized tissue models.
Killion, Elizabeth; Mohan, Kriti; Lee, Edward I.
Vascular tumors and malformations are unique in that affected cells exhibit disrupted angiogenesis. The current treatment options often yield suboptimal results. New insight into the genetics and molecular basis of vascular anomalies may pave the way for potential development of targeted therapy. The authors review the genetic and molecular basis of vascular anomalies and common associated syndromes. PMID:25045331
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vascular graft prosthesis. 870.3450 Section 870... prosthesis. (a) Identification. A vascular graft prosthesis is an implanted device intended to repair..., and to provide vascular access. It is commonly constructed of materials such as...
Manzur, Miguel F; Ham, Sung Wan; Elsayed, Ramsey; Abdoli, Sherwin; Simcox, Trevor; Han, Sukgu; Rowe, Vincent; Weaver, Fred A
In modern health care, vascular surgeons frequently serve as a unique resource to other surgical specialties for vascular exposure, repair, reconstruction, or control. These services occur both in planned and unplanned clinical settings. We analyzed the frequency, outcomes, and value of vascular services in this setting to other surgical specialties and the hospital. Intraoperative planned and unplanned vascular surgery operative consultations were reviewed over a 3-year period (2013-2016). Patient demographics, requesting surgical specialty, indication and type of vascular intervention, and work relative value units generated were recorded. Univariate and multivariate analysis of factors affecting a composite outcome of in-hospital and 30-day mortality or morbidity, or both, was performed. Seventy-six vascular surgery intraoperative consultations were performed, of which 56% of the consultations were unplanned. The most common unplanned consultation was for bleeding (33%). The aorta and lower extremity were the most common vascular beds requiring vascular services. The mean work relative value units generated per vascular surgery intervention was 23.8. In-hospital and 30-day mortality was 9.2%. No difference in mortality and morbidity was found between planned and unplanned consultations. Factors associated with the composite mortality/morbidity outcome were coronary artery disease (P = .002), heart failure (P = .02), total operative blood loss (P = .009), consultation for limb ischemia (P = .013), and vascular consultation for the lower extremity (P = .01). On multivariate analysis, high operative blood loss (>5000 mL) remained significant (P = .04), and coronary artery disease approached significance (P = .06). The need for vascular surgery services is frequent, involves diverse vascular beds, and occurs commonly in an unplanned setting. When requested, vascular surgery services effectively facilitate the completion of the nonvascular procedure, even
Bond, B; Gates, P E; Jackman, S R; Corless, L M; Williams, C A; Barker, A R
Acute exercise transiently improves endothelial function and protects the vasculature from the deleterious effects of a high-fat meal (HFM). We sought to identify whether this response is dependent on exercise intensity in adolescents. Twenty adolescents (10 male, 14.3 ± 0.3 yr) completed three 1-day trials: 1) rest (CON); 2) 8 × 1 min cycling at 90% peak power with 75 s recovery [high-intensity interval exercise (HIIE)]; and 3) cycling at 90% of the gas exchange threshold [moderate-intensity exercise (MIE)] 1 h before consuming a HFM (1.50 g/kg fat). Macrovascular and microvascular endothelial function was assessed before and immediately after exercise and 3 h after the HFM by flow-mediated dilation (FMD) and laser Doppler imaging [peak reactive hyperemia (PRH)]. FMD and PRH increased 1 h after HIIE [P < 0.001, effect size (ES) = 1.20 and P = 0.048, ES = 0.56] but were unchanged after MIE. FMD and PRH were attenuated 3 h after the HFM in CON (P < 0.001, ES = 1.78 and P = 0.02, ES = 0.59). FMD remained greater 3 h after the HFM in HIIE compared with MIE (P < 0.001, ES = 1.47) and CON (P < 0.001, ES = 2.54), and in MIE compared with CON (P < 0.001, ES = 1.40). Compared with CON, PRH was greater 3 h after the HFM in HIIE (P = 0.02, ES = 0.71) and MIE (P = 0.02, ES = 0.84), with no differences between HIIE and MIE (P = 0.72, ES = 0.16). Plasma triacylglycerol concentration and total antioxidant status concentration were not different between trials. We conclude that exercise intensity plays an important role in protecting the vasculature from the deleterious effects of a HFM. Performing HIIE may provide superior vascular benefits than MIE in adolescent groups.
Smith, Mark F; Ellmore, Mistrelle; Middleton, Geoff; Murgatroyd, Paul M; Gee, Thomas I
This study investigated the effects of a low to moderately intense resistance-band exercise intervention on cutaneous microvascular function in an older population. 18 sedentary healthy participants (age: 58±5) were assessed for their upper and lower-limb endothelial cutaneous vascular conductance using laser Doppler fluximetry with endothelial-dependent (80 μl acetylcholine chloride), and -independent vasodilation (80 μl sodium nitroprusside). In addition, participants underwent a range of functional assessments (cardiopulmonary fitness, strength, flexibility), and completed a perceived quality of life questionnaire. Participants were randomised into 2 groups: Exercise (EX) and Control (CON), and followed either an 8-week self-supervised home-based resistance-band intervention or maintained their habitual lifestyle. Following post-intervention assessment (n=16; EX=7, CON=9), EX improved acetylcholine-chloride-mediated endothelial-dependent vasodilation within the lower limb (cutaneous vascular conductance at 2 000 μCb; P<0.01), but without associated changes in the upper limb. Exercise, compared to CON, significantly affected sodium-nitroprusside-mediated independent vasodilation in the upper limb (P<0.01) at 2 000 μCb, but without associated changes in the lower limb. Of functional assessments, only lower limb strength and flexibility improved for EX (P<0.05). EX experienced positive changes within global measures of General Health, Bodily Pain and Energy/Fatigue (P<0.05). An 8-week home-based resistance-band exercise programme improves age-provoked microcirculatory endothelial vasodilation, but without concomitant changes in cardiopulmonary and anthropometric measures.
Casolino, V; Paraluppi, G; Manolitsi, O; Fontana, I; Antonucci, A; Tommasi, G V; Arcuri, V; Valente, U
The development in the number of patients for renal transplants has not been matched to the kidneys supplied. On this subject the authors think that this chronic deficit could be improved by making use of all the organs by using a series of technical means during bench surgery; which enable optimisation of use of kidneys with vascular abnormalities or those injured upon removal. The authors report their experience of 450 renal transplants operated between January 1981 and December 1985 and of the evolution vascular bench surgical techniques which enable use of a considerable number of kidneys which would otherwise have been discarded. Moreover, it helped the implant, shortened surgery time without prolonging hot ischemia, and did not increase the number of complications.
Ludovici, Valeria; Barthelmes, Jens; Nägele, Matthias P.; Enseleit, Frank; Ferri, Claudio; Flammer, Andreas J.; Ruschitzka, Frank; Sudano, Isabella
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
Diabetes mellitus is one of the most potent independent risk factors for the development of diabetic cerebral vascular disease (CVD). Many evidences suggested that hyperglycemia caused excess free fatty acids, the loss of endothelium-derived nitric oxide, insulin resistance, the prothrombotic state, endothelial dysfunction, the abnormal release of endothelial vasoactivators, vascular smooth muscle dysfunction, oxidative stress, and the downregulation of miRs participated in vessel generation and recovery as well as the balance of endotheliocytes. In turn, these abnormalities, mainly via phosphatidylinositol 3 kinase, mitogen-activated protein kinase, polyol, hexosamine, protein kinase C activation, and increased generation of advanced glycosylation end products pathway, play an important role in inducing diabetic CVD complication. A deeper comprehension of pathogenesis producing diabetic CVD could offer base for developing new therapeutic ways preventing diabetic CVD complications, therefore, in the paper we mainly reviewed present information about the possible pathogenesis of diabetic CVD complication. PMID:25685278
Barnes, R W
A decade ago vascular surgery "came of age" with formalization of accreditation of training programs and certification of subspecialists in the field. These events created turbulence in general surgery, with initial resistance to further subspecialization and fragmentation of the specialty. Subsequent reassessment of the trends in general surgery and its subspecialty disciplines has led to a reaffirmation of the integrity of the parent specialty. Recent proposals for reforms in resident training in general surgery and its subspecialties are currently being evaluated. Despite the current rapprochement between general and vascular surgery, many challenges remain for both disciplines. All surgeons, regardless of specialty, should broaden their respect for both "microscience," particularly molecular biology, and "macromedicine," including epidemiology, preventive medicine, and health services research.
Purdy, Ralph E.
The overall goal of the project is to characterize the effects of simulated microgravity on vascular function. Microgravity is simulated using the hindlimb unweighted (HU) rat, and the following vessels are removed from HU and paired control rats for in vitro analysis: abdominal aorta, carotid and femoral arteries, jugular and femoral veins. These vessels are cut into 3 mm long rings and mounted in tissue baths for the measurement of either isometric contraction, or relaxation of pre- contracted vessels. The isolated mesenteric vascular bed is perfused for the measurement of changes in perfusion pressure as an index of arteriolar constriction or dilation. This report presents, in addition to the statement of the overall goal of the project, a summary list of the specific hypotheses to be tested. These are followed by sections on results, conclusions, significance and plans for the next year.
Excess visceral adipose tissue is associated with increased risk of high blood pressure, lipid disorders, type 2 diabetes, and cardiovascular disease. Adipose tissue is an endocrine organ with multiple humoral and metabolic roles in regulating whole-body physiology. However, perivascular adipose tissue (PVAT) also plays a functional role in regulating the contractile state of the underlying smooth muscle cell layer. Work during the past decade has shown that this adipose-vascular coupling is achieved by production of numerous substances released from PVAT. Animal disease models have been instrumental in identifying biological and pathophysiological functions of this regulation. These studies have produced strong evidence that alterations in the paracrine control of PVAT in the regulation of arterial tone contribute to vascular dysfunction in obesity, hypertension, and cardiometabolic disease. Perivascular relaxing factors, or perhaps their putative targets, might represent exciting new targets for the prevention and treatment of cardiovascular and metabolic diseases.
This open study was designed to assess efficacy and safety of long-term therapy with cerebrolysin in 48 patients aged 59-77 years with mild and moderately severe vascular dementia. The slowdown in the progress of this condition during the 3-year treatment period was evaluated. The efficacy and safety of the drug was assessed clinically and with the use of standard scales and neuropsychological tests. The long-term therapy with cerebrolysin was shown to be safe and highly efficacious as indicated by the improvement of cognitive and motor functions both at early and late stages of the treatment regardless of the severity of the disease. It is concluded that long-term therapy with cerebrolysin slows down the progress of vascular dementia and prevent deterioration of cognitive abilities.
Katsiki, Niki; Perez-Martinez, Pablo; Mikhailidis, Dimitri P
Elevated homocysteine (Hcy) levels are predictors of cardiovascular disease (CVD). Hyperhomocysteinemia has also been associated with total and CVD mortality. However, whether Hcy is just a marker or plays a causal role in CVD remains to be elucidated. In this narrative review, we discuss the associations between Hcy and non-cardiac vascular diseases, namely stroke, peripheral artery disease (PAD), carotid artery disease, chronic kidney disease (CKD), atherosclerotic renal artery stenosis (ARAS), abdominal aortic aneurysm (AAA) and erectile dysfunction (ED). The effects of several drugs on Hcy levels are also considered. Folic acid, vitamin B6 and B12 supplementation can significantly decrease circulating Hcy concentrations but their effects on CVD risk reduction are conflicting. No current guidelines recommend the routine screening of Hcy levels in patients with non-cardiac vascular diseases. Therefore, further research is needed to elucidate the use of Hcy in the clinical practice.
Dubey, Raghvendra K.; Jackson, Edwin K.
2-Methoxyestradiol (2-ME) is a biologically active metabolite of 17β-estradiol that appears to inhibit key processes associated with cell replication in vitro; it may have potent growth-inhibitory effects on proliferating cells, including smooth muscle cells and endothelial cells and may be antiangiogenic. Because of these potential roles for 2-ME, its lack of cytotoxicity and its low estrogenic activity, we hypothesize that 2-ME could be a valuable therapeutic molecule for prevention and treatment of cardiovascular diseases. Whether 2-ME is as efficacious in vivo as it is in vitro at modulating vascular processes remains controversial. Here we discuss recent developments regarding mechanisms by which 2-ME might regulate vascular activity and angiogenesis and speculate on the therapeutic implications of these developments. PMID:19734053
Wang, Pei; Vanhoutte, Paul M; Miao, Chao-Yu
Nicotinamide phosphoribosyltransferase is the rate-limiting enzyme that catalyzes the first step in the biosynthesis of nicotinamide adenine dinucleotide from nicotinamide. This protein was originally cloned as a putative pre-B cell colony-enhancing factor and also found to be a visceral fat-derived adipokine (visfatin). As a multifunctional protein, visfatin plays an important role in immunity, metabolism, aging, inflammation, and responses to stress. Visfatin also participates in several pathophysiological processes contributing to cardio-cerebro-vascular diseases, including hypertension, atherosclerosis, ischemic heart disease, and ischemic stroke. However, whether visfatin is a friend or a foe in these diseases remains uncertain. This brief review focuses on the current understanding of the complex role of visfatin in the cardio-cerebro-vascular system under normal and pathophysiological conditions.
In order to learn more about the cause of coronary heart diseases and develop diagnostic tools, the extraction and visualization of vascular structures from volumetric scans for further analysis is an important step. By determining a geometric representation of the vasculature, the geometry can be inspected and additional quantitative data calculated and incorporated into the visualization of the vasculature. To provide a more user-friendly visualization tool, virtual environment paradigms can be utilized. This paper describes techniques for interactive rendering of large-scale vascular structures within virtual environments. This can be applied to almost any virtual environment configuration, such as CAVE-type displays. Specifically, the tools presented in this paper were tested on a Barco I-Space and a large 62x108 inch passive projection screen with a Kinect sensor for user tracking.
McGregor, Thomas B.; Patel, Premal; Sener, Alp; Chan, Gabriel
Summary Laparoscopic donor nephrectomy (LDN) is the gold standard for kidney donation. Recent literature has led to considerable debate regarding the safest route to provide vascular control during this procedure. The most common devices used for vascular control during LDN are staplers and surgical clips. Opinions regarding the safety of these devices vary, as both are prone to dysfunction. Certain clips have already been contraindicated for use on the donor artery owing to reports of catastrophic complications of falling off. Donor safety is paramount to the continued success of renal transplantation in Canada. A review of existing practice at each institution may be called for to ensure the safest standards possible are in place. An appendix to this commentary is available at canjsurg.ca. PMID:28570212
McGregor, Thomas B; Patel, Premal; Sener, Alp; Chan, Gabriel
Laparoscopic donor nephrectomy (LDN) is the gold standard for kidney donation. Recent literature has led to considerable debate regarding the safest route to provide vascular control during this procedure. The most common devices used for vascular control during LDN are staplers and surgical clips. Opinions regarding the safety of these devices vary, as both are prone to dysfunction. Certain clips have already been contraindicated for use on the donor artery owing to reports of catastrophic complications of falling off. Donor safety is paramount to the continued success of renal transplantation in Canada. A review of existing practice at each institution may be called for to ensure the safest standards possible are in place. An appendix to this commentary is available at canjsurg.ca.
Hood, Elizabeth; Simone, Eric; Wattamwar, Paritosh; Dziubla, Thomas; Muzykantov, Vladimir
Antioxidant enzymes (AOEs) catalase and superoxide dismutase (SOD) detoxify harmful reactive oxygen species, but the therapeutic utility of AOEs is hindered by inadequate delivery. AOE modification by polyethylene glycol (PEG) and encapsulation in PEG-coated liposomes increases the AOE bioavailability and enhances protective effects in animal models. Pluronic-based micelles formed with AOEs show even more potent protective effects. Furthermore, polymeric nanocarriers (PNCs) based on PEG-copolymers protect encapsulated AOEs from proteolysis and improve delivery to the target cells, such as the endothelium lining the vascular lumen. Antibodies to endothelial determinants conjugated to AOEs or AOE carriers provide targeting and intracellular delivery. Targeted liposomes, protein conjugates and magnetic nanoparticles deliver AOEs to sites of vascular oxidative stress in the cardiovascular, pulmonary and nervous systems. Further advances in nanodevices for AOE delivery will provide a basis for the translation of this approach in the clinical domain. PMID:21929460
Riedemann-Wistuba, M; Alonso-Pérez, M; Llaneza-Coto, J M
Although there are currently less invasive techniques available for the treatment of spinal injuries, open surgery is still required in many cases. Vascular injuries occurring during lumbar spine surgery, although uncommon, are of great importance due to their potential gravity. Clinical manifestations vary from an acute hemorrhagic shock that needs urgent treatment to save the patient's life, to insidious injuries or an asymptomatic evolution, and should be studied to choose the best therapeutic alternative. Four cases are reported that represent this range of possibilities and emphasize the importance of a careful surgical technique during lumbar spine interventions, and the need for high clinical suspicion, essential for the early diagnosis of these vascular complications. The current therapeutic options are also discussed. Copyright © 2014 SECOT. Published by Elsevier Espana. All rights reserved.
Basran, G.S.; Hardy, J.G.
A simple, noninvasive technique for monitoring pulmonary vascular permeability in patients in critical care units is discussed. High vascular permeability is observed in patients with clinically defined adult respiratory distress syndrome (ARDS) but not in patients with hydrostatic pulmonary edema or in patients with minor pulmonary insults who are considered to be at risk of developing ARDS. The technique has been used in the field of therapeutics and pharmacology to test the effects of the putative antipermeability agents methylprednisolone and terbutaline sulfate. There appears to be a good correlation between the acute inhibitory effect of either drug on transferrin exudation and patient prognosis. Thus, a byproduct of such drug studies may be an index of survival in patients with established ARDS.
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.
Diefenbeck, Michael; Nerlich, Andreas; Schneeberger, Stefan; Wagner, Frithjof; Hofmann, Gunther O
Composite tissue allotransplantation represents a new discipline in reconstructive surgery. Over the past 10 years, we have performed six human vascularized allogeneic knee transplantations. All of these grafts have been lost within the first 56 months. A histomorphologic assessment of the latest case resulted in the detection of diffuse concentric fibrous intimal thickening and occlusion of graft vessels. Findings are comparable with cardiac allograft vasculopathy. The lack of adequate tools for monitoring graft rejection might have allowed multiple untreated episodes of acute rejection, triggering myointimal proliferation and occlusion of graft vessels. Graft vasculopathy represents an obstacle to long-term vascularized bone and joint allograft survival, and adequate tools for monitoring need to be developed.
Cleary, Muriel A; Geiger, Erik; Grady, Conor; Best, Cameron; Naito, Yuji; Breuer, Christopher
It is the ultimate goal of tissue engineering: an autologous tissue engineered vascular graft (TEVG) that is immunologically compatible, nonthrombogenic, and can grow and remodel. Currently, native vessels are the preferred vascular conduit for procedures such as coronary artery bypass (CABG) or peripheral bypass surgery. However, in many cases these are damaged, have already been harvested, or are simply unusable. The use of synthetic conduits is severely limited in smaller diameter vessels due to increased incidence of thrombosis, infection, and graft failure. Current research has therefore energetically pursued the development of a TEVG that can incorporate into a patient's circulatory system, mimic the vasoreactivity and biomechanics of the native vasculature, and maintain long-term patency. Copyright © 2012. Published by Elsevier Ltd.
Khalil, Raouf A.
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 concert with
Khalil, Raouf A
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 Ca(2+) concentration ([Ca(2+)]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 Ca(2+)-dependent and Ca(2+)-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 [Ca(2+)]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 metalloproteinase (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
Greco, Stephanie H; Torres-Hernandez, Alejandro; Kalabin, Aleksandr; Whiteman, Clint; Rokosh, Rae; Ravirala, Sushma; Ochi, Atsuo; Gutierrez, Johana; Salyana, Muhammad Atif; Mani, Vishnu R; Nagaraj, Savitha V; Deutsch, Michael; Seifert, Lena; Daley, Donnele; Barilla, Rocky; Hundeyin, Mautin; Nikifrov, Yuriy; Tejada, Karla; Gelb, Bruce E; Katz, Steven C; Miller, George
Con A hepatitis is regarded as a T cell-mediated model of acute liver injury. Mincle is a C-type lectin receptor that is critical in the immune response to mycobacteria and fungi but does not have a well-defined role in preclinical models of non-pathogen-mediated inflammation. Because Mincle can ligate the cell death ligand SAP130, we postulated that Mincle signaling drives intrahepatic inflammation and liver injury in Con A hepatitis. Acute liver injury was assessed in the murine Con A hepatitis model using C57BL/6, Mincle(-/-), and Dectin-1(-/-) mice. The role of C/EBPβ and hypoxia-inducible factor-1α (HIF-1α) signaling was assessed using selective inhibitors. We found that Mincle was highly expressed in hepatic innate inflammatory cells and endothelial cells in both mice and humans. Furthermore, sterile Mincle ligands and Mincle signaling intermediates were increased in the murine liver in Con A hepatitis. Most significantly, Mincle deletion or blockade protected against Con A hepatitis, whereas Mincle ligation exacerbated disease. Bone marrow chimeric and adoptive transfer experiments suggested that Mincle signaling in infiltrating myeloid cells dictates disease phenotype. Conversely, signaling via other C-type lectin receptors did not alter disease course. Mechanistically, we found that Mincle blockade decreased the NF-κβ-related signaling intermediates C/EBPβ and HIF-1α, both of which are necessary in macrophage-mediated inflammatory responses. Accordingly, Mincle deletion lowered production of nitrites in Con A hepatitis and inhibition of both C/EBPβ and HIF-1α reduced the severity of liver disease. Our work implicates a novel innate immune driver of Con A hepatitis and, more broadly, suggests a potential role for Mincle in diseases governed by sterile inflammation.
Greco, Stephanie H.; Torres-Hernandez, Alejandro; Kalabin, Aleksandr; Whiteman, Clint; Rokosh, Rae; Ravirala, Sushma; Ochi, Atsuo; Gutierrez, Johana; Salyana, Muhammad Atif; Mani, Vishnu R.; Nagaraj, Savitha V.; Deutsch, Michael; Seifert, Lena; Daley, Donnele; Barilla, Rocky; Hundeyin, Mautin; Nikifrov, Yuriy; Tejada, Karla; Gelb, Bruce E.; Katz, Steven C.; Miller, George
Concanavalin-A (Con-A) hepatitis is regarded as a T cell-mediated model of acute liver injury. Mincle is a C-type lectin receptor (CLR) that is critical in the immune response to mycobacteria and fungi, but does not have a well-defined role in pre-clinical models of non-pathogen mediated inflammation. Since Mincle can ligate the cell death ligand SAP130, we postulated that Mincle signaling drives intrahepatic inflammation and liver injury in Con-A hepatitis. Acute liver injury was assessed in the murine Con-A hepatitis model using C57BL/6, Mincle−/−, and Dectin-1−/− mice. The role of C/EBPβ and HIF-1α signaling was assessed using selective inhibitors. We found that Mincle was highly expressed in hepatic innate inflammatory cells and endothelial cells in both mice and humans. Furthermore, sterile Mincle ligands and Mincle signaling intermediates were increased in the murine liver in Con-A hepatitis. Most significantly, Mincle deletion or blockade protected against Con-A hepatitis whereas Mincle ligation exacerbated disease. Bone marrow chimeric and adoptive transfer experiments suggested that Mincle signaling in infiltrating myeloid cells dictates disease phenotype. Conversely, signaling via other CLRs did not alter disease course. Mechanistically, we found that Mincle blockade decreased the NF-κβ related signaling intermediates, C/EBPβ and HIF-1α, both of which are necessary in macrophage-mediated inflammatory responses. Accordingly, Mincle deletion lowered production of nitrites in Con-A hepatitis and inhibition of both C/EBPβ and HIF1-α reduced the severity of liver disease. Our work implicates a novel innate immune driver of Con-A hepatitis and, more broadly, suggests a potential role for Mincle in diseases governed by sterile inflammation. PMID:27559045
Weis, Sara M.; Cheresh, David A.
Although vascular endothelial growth factor (VEGF) induces angiogenesis, it also disrupts vascular barrier function in diseased tissues. Accordingly, VEGF expression in cancer and ischaemic disease has unexpected pathophysiological consequences. By uncoupling endothelial cell-cell junctions VEGF causes vascular permeability and oedema, resulting in extensive injury to ischaemic tissues after stroke or myocardial infarction. In cancer, VEGF-mediated disruption of the vascular barrier may potentiate tumour cell extravasation, leading to widespread metastatic disease. Therefore, by blocking the vascular permeability promoting effects of VEGF it may be feasible to reduce tissue injury after ischaemic disease and minimize the invasive properties of circulating tumour cells.
Cai, Yiyu; Chui, Cheekong K.; Ye, Xiuzi; Anderson, James H.; Wang, Yaoping
This paper describes a computerized simulation system for minimally invasive vascular interventions using Virtual-Reality (VR) based technology. A virtual human patient is constructed using the Visible Human Data (VHD). A knowledge-based human vascular network is developed to describe human vascular anatomy with diseased lesions for different interventional applications. A potential field method is applied to model the interaction between the blood vessels and vascular catheterization devices. A haptic interface is integrated with the computer simulation system to provide tactile sensations to the user during the simulated catheterization procedures. The system can be used for physician training and for pre-treatment planning of interventional vascular procedures.
Smith, Matthew C.P.; Li, Dean Y.; Whitehead, Kevin J.
Purpose of review The genetic basis for a variety of vascular malformation syndromes have been described, with an increasing functional understanding of the associated genes. Recent findings Genes responsible for familial vascular malformation syndromes have increasingly been shown to be involved in the control of vascular stability. Summary Genes involved in vascular stability pathways are good candidates for causing vascular malformation syndromes. Although these findings confirm the biologic importance of the involved pathways, further explanations are required to describe the focal nature of disease. PMID:20308891
Prochazka, V.; Hrbac, T.; Chmelova, J.; Skoloudik, D.; Prochazka, M.
Summary PHACE(S) syndrome is an acronym for neurocutaneous disease encompassing the expression of (P) posterior cranial fossa malformations, (H) facial haemangiomas, (A) arterial anomalies, (C) aortic coarctaion and other cardiac defects, (E) eye abnormalities and (S) for sternal malformation or stenotic arterial diseases. We report on a case of PHACE syndrome complete expression with persistent fetal vascular anomalies unusually in a 55-year-old women with large bilateral facial and neck haemangioma and posterior fossa circulation insufficiency. PMID:20584448
Husmann, Marc; Barton, Matthias
For centuries, physicians have depended on the use of written information to gain knowledge. Book printing and binding introduced by Gutenberg in the fifteenth century revolutionized and accelerated the distribution of information. Advancing medical knowledge and progress is not only linked to the scientific quality of a discovery determining it will be accepted by the peers but also by its communication and sharing of new findings with the medical community. All these factors determine whether new knowledge will advance and improve clinical practice, medical education, and ultimately, patient care, and human health. In the past decade medical publishing has witnessed a revolution with regard to the instant, online availability of published “open access” information, which can be accessed and printed from any computer connected to the internet. As an example, how language and availability of printed information may affect distribution of knowledge, we discuss the publication of the first results of balloon angioplasty in patients with peripheral vascular disease 40 years ago by Andreas Grüntzig, M.D. at the University of Zürich. Vascular Medicine, as part of Frontiers in Cardiovascular Medicine, will provide open access provided to all published content for sharing and distributing new and most up-to-date information on clinical practice and medical knowledge in vascular medicine. We anticipate that the ongoing transformation of scientific publishing through open access will further accelerate this process and make new knowledge available even faster. Immediate, unrestricted, and rapid access to the most current knowledge published will play a role in maintaining and advancing human vascular health across the globe. PMID:26664857
Haritharan, T; Islah, M; Zulfiqar, A; Thambi Dorai, C R
Isolated involvement of the clitoris by vascular malformation (VM) is very rare. Clinically, the lesion simulates female pseudohermaphroditism. A five-year-old girl presented with clitoromegaly and a clinical diagnosis of solitary VM of the clitoris was made. Magnetic resonance imaging showed characteristic features and confirmed the diagnosis and the extent of the VM. This is the first reported case of isolated involvement of the clitoris by VM to be diagnosed preoperatively.
Adams, Tessa; Wan, Elaine; Wei, Ying; Wahab, Romina; Castagna, Francesco; Wang, Gang; Emin, Memet; Russo, Cesare; Homma, Shunichi; Le Jemtel, Thierry H.
BACKGROUND: The relative risk for cardiovascular diseases in passive smokers is similar to that of active smokers despite almost a 100-fold lower dose of inhaled cigarette smoke. However, the mechanisms underlying the surprising susceptibility of the vascular tissue to the toxins in secondhand smoke (SHS) have not been directly investigated. The aim of this study was to investigate directly vascular endothelial cell function in passive smokers. METHODS: Using a minimally invasive method of endothelial biopsy, we investigated directly the vascular endothelium in 23 healthy passive smokers, 25 healthy active smokers, and 23 healthy control subjects who had never smoked and had no regular exposure to SHS. Endothelial nitric oxide synthase (eNOS) function (expression of basal eNOS and activated eNOS [phosphorylated eNOS at serine1177 (P-eNOS)]) and expression of markers of inflammation (nuclear factor-κB [NF-κB]) and oxidative stress (nitrotyrosine) were assessed in freshly harvested venous endothelial cells by quantitative immunofluorescence. RESULTS: Expression of eNOS and P-eNOS was similarly reduced and expression of NF-κB was similarly increased in passive and active smokers compared with control subjects. Expression of nitrotyrosine was greater in active smokers than control subjects and similar in passive and active smokers. Brachial artery flow-mediated dilation was similarly reduced in passive and active smokers compared with control subjects, consistent with reduced endothelial NO bioavailability. CONCLUSIONS: Secondhand smoking increases vascular endothelial inflammation and reduces active eNOS to a similar extent as active cigarette smoking, indicating direct toxic effects of SHS on the vasculature. PMID:25742439
Stott, D J; Spilg, E; Campbell, A M; Rumley, A; Mansoor, M A; Lowe, G D
Abnormalities of coagulation and fibrinolysis may play an important role in the pathogenesis of ischaemic stroke and vascular dementia. We aimed to determine whether haemostatic function is altered in acute recent-onset or chronic ischaemic cerebrovascular disease. We studied consecutive patients with ischaemic stroke (n = 74) and vascular dementia (n = 42) compared with healthy controls (n = 40) in a case-control study. The ischaemic stroke group was assessed twice, 3-10 days after the acute stroke and at 1-3 months. Fibrinogen, fibrin D-dimer (marker of fibrin turnover) and von Willebrand factor (vWF) (marker of endothelial disturbance) were elevated acutely (P < 0.0001) and in the convalescent phase after ischaemic stroke (P < 0.0001, P < 0.0001, and P < 0.01 respectively, compared with controls). Similar results were seen in the vascular dementia group. Stepwise multivariate regression analyses showed that cerebrovascular disease correlated independently with fibrinogen (P < 0.001) and fibrin D-dimer levels (P < 0.001), while vWF correlated independently with electrocardiograph evidence of ischaemic heart disease (P = 0.004). Changes between acute and convalescent phases in ischaemic stroke were slightly inconsistent. However, in the acute stage there were tendencies for fibrinogen, D-dimer and vWF to be increased, and factor VIII was significantly higher. Abnormalities of haemostasis, including increased fibrin turnover and endothelial disturbance, are found in both acute and chronic cerebral ischaemia. Many of these patients have co-existent ischaemic heart disease and this may contribute to some of these changes. Acute ischaemic stroke is associated with transient changes in haemostatic factors; however, most abnormalities persist into the convalescent phase, and are also demonstrable in subjects with vascular dementia.
de Almeida, Carlos Eduardo Saldanha
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
Morgan, Ruth A.; Keen, John A.; Walker, Brian R.; Hadoke, Patrick W. F.
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. PMID:27684374
Morgan, Ruth A; Keen, John A; Walker, Brian R; Hadoke, Patrick W F
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.
Roman, M J; Saba, P S; Pini, R; Spitzer, M; Pickering, T G; Rosen, S; Alderman, M H; Devereux, R B
Although vascular damage in the noncoronary circulation is a major cause of complications in hypertension, relatively little is known of the in vivo geometry and function of the arterial circulation in patients with uncomplicated hypertension or of their relation to left ventricular hypertrophy, a marker of enhanced risk of cardiovascular complications. Wall thickness and internal diameter of the common carotid artery and the presence of atherosclerosis within the extracranial carotid arteries were determined by ultrasound in 43 asymptomatic hypertensive patients and 43 normotensive subjects matched for sex, age, and body size. Vascular stiffness was estimated from simultaneous superimposed carotid pressure waveforms obtained with an external solid-state transducer. Left ventricular size and function were determined echocardiographically. Compared with normal subjects, hypertensive patients had greater left ventricular absolute and relative wall thicknesses, left ventricular mass, and carotid absolute and relative wall thicknesses (p < 0.005). Carotid intimal-medial thickness exceeded the 95th percentile of normal values in 28% of hypertensive patients (p < 0.01). Carotid atherosclerosis was equally prevalent within the two blood pressure groups and was associated with older age, larger left ventricular and carotid wall thicknesses, and carotid diameter. Despite similar carotid pulse pressures, vascular stiffness was significantly increased in the hypertensive patients. Among the population as a whole, significant relations existed between cardiac and vascular wall thicknesses and internal dimensions. In multivariate analyses, these relations were statistically independent of age and blood pressure. The present study documents the presence of geometric and functional changes within the common carotid artery in uncomplicated hypertension that parallel findings within the left ventricle. The potential contribution of these changes to the cardiovascular complications
J. D. Haines; C .M. Regan
This appendix provides a list of 230 vascular plant taxa that were field identified and/or collected over the period 1986-1990. Field identification was done by C.L. Simmons in 1986-87 (see Chapter 2). Subsequent taxa were field identified, collected, and verified by J.D. Haines and C.M. Regan in 1988-90. Voucher specimens were verified by taxonomists at the Rocky...
Aggarwal, Saurabh; Gross, Christine M.; Sharma, Shruti; Fineman, Jeffrey R.; Black, Stephen M.
The pathogenesis of pulmonary hypertension is a complex multifactorial process that involves the remodeling of pulmonary arteries. This remodeling process encompasses concentric medial thickening of small arterioles, neomuscularization of previously nonmuscular capillary-like vessels, and structural wall changes in larger pulmonary arteries. The pulmonary arterial muscularization is characterized by vascular smooth muscle cell (SMC) hyperplasia and hypertrophy. In addition, in uncontrolled pulmonary hypertension, the clonal expansion of apoptosis-resistant endothelial cells leads to the formation of plexiform lesions. Based upon a large number of studies in animal models, the three major stimuli that drive the vascular remodeling process are inflammation, shear stress and hypoxia. Although, the precise mechanisms by which these stimuli impair pulmonary vascular function and structure are unknown, reactive oxygen species (ROS)-mediated oxidative damage appears to play an important role. ROS are highly reactive due to their unpaired valence shell electron. Oxidative damage occurs when the production of ROS exceeds the quenching capacity of the anti-oxidant mechanisms of the cell. ROS can be produced from complexes in the cell membrane (nicotinamide adenine dinucleotide phosphate-oxidase), cellular organelles (peroxisomes and mitochondria), and in the cytoplasm (xanthine oxidase). Furthermore, low levels of tetrahydrobiopterin (BH4) and L-arginine the rate limiting co-factor and substrate for endothelial nitric oxide synthase (eNOS), can cause the uncoupling of eNOS, resulting in decreased NO production and increased ROS production. This review will focus on the ROS generation systems, scavenger antioxidants, and oxidative stress associated alterations in vascular remodeling in pulmonary hypertension. PMID:23897679
Chen, Yongmei; Hao, Qi; Kim, Helen; Su, Hua; Letarte, Michelle; Karumanchi, S. Ananth; Lawton, Michael T.; Barbaro, Nicholas M.; Yang, Guo-Yuan; Young, William L.
Objective Brain arteriovenous malformations (AVMs) are an important cause of neurological morbidity in young adults. The pathophysiology of these lesions is poorly understood. A soluble form of endoglin (sEng) has been shown to cause endothelial dysfunction and induce preeclampsia. We tested if sEng would be elevated in brain AVM tissues relative to epilepsy brain tissues, and also investigated whether sEng overexpression via gene transfer in the mouse brain would induce vascular dysplasia and associated changes in downstream signaling pathways. Methods Expression levels of sEng in surgical specimens were determined by Western blot assay and ELISA. Vascular dysplasia, levels of MMP and oxidative stress were determined by immunohistochemistry and gelatin zymography. Results Brain AVMs (n=33) had higher mean sEng levels (245 ± 175 vs 100 ± 60, % of control, P=0.04) compared with controls (n=8), as determined by Western blot. In contrast, membrane-bound Eng was not significantly different (108 ± 79 vs 100 ± 63, % of control, P=0.95). sEng gene transduction in the mouse brain induced abnormal vascular structures. It also increased matrix metalloproteinase (MMP) activity by 490 ± 30% (MMP-9), 220 ± 30% (MMP-2), and oxidants by 260 ± 20% (4-hydroxy-2-nonenal) at 2 weeks after injection, suggesting that MMPs and oxidative radicals may mediate sEng-induced pathological vascular remodeling. Interpretation The results suggest that elevated sEng may play a role in the generation of sporadic brain AVMs. Our findings may provide new targets for therapeutic intervention for patients with brain AVMs. PMID:19670444
Leblanc, Gabrielle G.; Golanov, Eugene; Awad, Issam A.; Young, William L.
Background and Purpose This review discusses recent research on the genetic, molecular, cellular, and developmental mechanisms underlying the etiology of vascular malformations of the brain (VMBs), including cerebral cavernous malformation (CCM), sporadic brain arteriovenous malformation (AVM), and the AVMs of hereditary hemorrhagic telangiectasia (HHT). Summary of Review The identification of gene mutations and genetic risk factors associated with CCM, HHT, and sporadic AVM has enabled the development of animal models for these diseases and provided new insights into their etiology. All of the genes associated with VMBs to date have known or plausible roles in angiogenesis and vascular remodeling. Recent work suggests that the angiogenic process most severely disrupted by VMB gene mutation is that of vascular stabilization, the process whereby vascular endothelial cells form capillary tubes, strengthen their intercellular junctions, and recruit smooth muscle cells to the vessel wall. In addition, there is now good evidence that in some cases CCM lesion formation involves a genetic two-hit mechanism, in which a germline mutation in one copy of a CCM gene is followed by a somatic mutation in the other copy. There is also increasing evidence that environmental second hits can produce lesions when there is a mutation to a single allele of a VMB gene. Conclusions Recent findings begin to explain how mutations in VMB genes render vessels vulnerable to rupture when challenged with other inauspicious genetic or environmental factors, and have suggested candidate therapeutics. Understanding of the cellular mechanisms of VMB formation and progression in humans has lagged behind that in animal models. New knowledge of lesion biology will spur new translational work. Several well-established clinical and genetic database efforts are already in place, and further progress will be facilitated by collaborative expansion and standardization of these. PMID:19834013
Tsimerman, Gala; Roguin, Ariel; Bachar, Anat; Melamed, Eyal; Brenner, Benjamin; Aharon, Anat
Type 2 diabetes mellitus (T2DM) is associated with increased coagulability and vascular complications. Circulating microparticles (MPs) are involved in thrombosis, inflammation, and angiogenesis. However, the role of MPs in T2DM vascular complications is unclear. We characterised the cell origin and pro-coagulant profiles of MPs obtained from 41 healthy controls and 123 T2DM patients with coronary artery disease, retinopathy and foot ulcers. The effects of MPs on endothelial cell coagulability and tube formation were evaluated. Patients with severe diabetic foot ulcers expressed the highest levels of MPs originated from platelet and endothelial cells and negatively-charged phospholipid-bearing MPs. MP coagulability, calculated from MP tissue factor (TF) and TF pathway inhibitor (TFPI) ratio, was low in healthy controls and in diabetic retinopathy patients (<0.7) but high in patients with coronary artery disease and foot ulcers (>1.8, p≥0.002). MPs of all T2DM patients induced a more than two-fold increase in endothelial cell TF (antigen and gene expression) but did not affect TFPI levels. Tube networks were longest and most stable in endothelial cells that were incubated with MPs of healthy controls, whereas no tube formation occurred in MPs of diabetic patients with coronary artery disease. MPs of diabetic retinopathy and diabetic foot ulcer patients induced branched tube networks that were unstable and collapsed over time. This study demonstrates that MP characteristics are related to the specific type of vascular complications and may serve as a bio-marker for the pro- coagulant state and vascular pathology in patients with T2DM.
Zhao, Yingzi; Vanhoutte, Paul M; Leung, Susan W S
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.
Sands, Jeffrey J; Ferrell, Lori M; Perry, Michael A
Vascular access dysfunction is the most frequent cause of hospitalization for end-stage renal disease (ESRD) patients. Our system of vascular access care and industry standards developed for historic reasons have resulted in a haphazard approach to access management. The Dialysis Outcome Quality Initiative has provided a road map for improving vascular access management. However, despite widespread acceptance, these recommendations are not routinely followed. This is largely the result of inertia coupled with systemic barriers to improving access outcomes. These barriers include lack of funded pre-ESRD care and preoperative imaging, lack of reimbursement for access monitoring, unavailable surgical and interventional suites, erosion of the real value of the composite rate, bundling of additional new services without rate adjustment, poor accountability of surgeons and hospitals, and a reimbursement system that rewards procedures and, in particular, graft and catheter placement. Currently, Center for Medicare and Medicaid Services is reevaluating the composite rate and its included bundle of services. To provide the best access care with the fewest complications while insuring multidisciplinary involvement and accountability, a realistic appraisal and realignment of incentives must be developed to insure improvement of access care in the United States.
Agrawal, Rupesh; Sherwood, Joseph; Chhablani, Jay; Ricchariya, Ashutosh; Kim, Sangho; Jones, Philip H; Balabani, Stavroula; Shima, David
Microvascular circulation plays a vital role in regulating physiological functions, such as vascular resistance, and maintaining organ health. Pathologies such as hypertension, diabetes, or hematologic diseases affect the microcirculation posing a significant risk to human health. The retinal vasculature provides a unique window for non-invasive visualisation of the human circulation in vivo and retinal vascular image analysis has been established to predict the development of both clinical and subclinical cardiovascular, metabolic, renal and retinal disease in epidemiologic studies. Blood viscosity which was otherwise thought to play a negligible role in determining blood flow based on Poiseuille's law up to the 1970s has now been shown to play an equally if not a more important role in controlling microcirculation and quantifying blood flow. Understanding the hemodynamics/rheology of the microcirculation and its changes in diseased states remains a challenging task; this is due to the particulate nature of blood, the mechanical properties of the cells (such as deformability and aggregability) and the complex architecture of the microvasculature. In our review, we have tried to postulate a possible role of red blood cell (RBC) biomechanical properties and laid down future framework for research related to hemorrheological aspects of blood in patients with retinal vascular disorders.
Cirillo, Massimo; Bilancio, Giancarlo; Cirillo, Chiara
A 64-year-old man was hospitalized in 2002 with symptoms of stupor, weakness, and renal colic. The clinical examination indicated borderline hypertension, small masses in the glutei, and polyuria. Laboratory tests evidenced high serum concentrations of creatinine, calcium, and phosphate. Imaging assessments disclosed widespread vascular calcifications, gluteal calcifications, and pelvic ectasia. Subsequent lab tests indicated suppressed serum parathyroid hormone, extremely high serum 25-hydroxy vitamin D, and normal serum 1,25-dihydroxy vitamin D. Treatment was started with intravenous infusion of saline and furosemide due to the evidence of hypercalcemia. Prednisone and omeprazole were added given the evidence of hypervitaminosis D. The treatment improved serum calcium, kidney function, and consciousness. The medical history disclosed recent treatment with exceptionally high doses of slow-release intra-muscular cholecalciferol and the recent excretion of urinary stones. The patient was discharged when it was possible to stop the intravenous treatment. The post-discharge treatment included oral hydration, furosemide, prednisone and omeprazole for approximately 6 months up to complete resolution of the hypercalcemia. The patient came back 12 years later because of microhematuria. Lab tests were normal for calcium/phosphorus homeostasis and kidney function. Imaging tests indicated only minor vascular calcifications. This is the first evidence of reversible vascular calcifications secondary to hypervitaminosis D.
Sequeira, Adrian; Naljayan, Mihran; Vachharajani, Tushar J
Dialysis vascular access management in the United States changed significantly after National Kidney Foundation-Kidney Disease Outcome Quality Initiative (NKF-KDOQI) clinical practice guidelines were first published in 1997. The Centers for Medicare and Medicaid Service adopted these guidelines and in collaboration with the End-Stage Renal Disease Networks established the Fistula First Breakthrough Initiative (FFBI) in 2003 to improve the rate of arteriovenous fistula use over arteriovenous graft and central venous catheter in the dialysis population. The implementation of guidelines and FFBI has led to a significant increase in the arteriovenous fistula use in the prevalent dialysis population. The guidelines are criticized for being opinion based and often impractical. Over the past 2 decades, the patient population undergoing dialysis has become older with complex comorbidities and challenges for creating an ideal vascular access. Advancing knowledge about access pathophysiology, improved treatment options, and improved process of care with team approach model point toward diminishing relevance of few of the existing guidelines. Moreover, several guidelines remain controversial and may be leading to clinical decisions that may be unfavorable to the patients. The review discusses the historical aspect of vascular access care in the United States and evolution of current practice standards and controversies surrounding few of these guidelines in the current time. Published by Elsevier Inc.
Brecht, Anna; Bartsch, Cornelia; Baumann, Gert; Stangl, Karl; Dschietzig, Thomas
Increased expression of endothelial adhesion molecules, high levels of the monocyte chemoattractant protein-1 (MCP-1) and enhanced VLA4 integrin/VCAM-1 and CCR-2/MCP-1 interactions are initial steps in vascular inflammation. We sought to determine whether relaxin, a potent vasodilatory and anti-fibrotic agent, mitigates these early events compromising endothelial integrity. The effect of relaxin coincubation on the TNF-α-stimulated expression of the adhesion molecules VCAM-1, ICAM-1 and E-selectin; the MCP-1 expression by human umbilical vein endothelial cells (HUVEC) and human aortic smooth muscle cells (HAoSMC); as well as on direct monocyte-endothelium cell adhesion was quantified by ELISA or adhesion assay. CCR-2 and PECAM expression on HUVEC and THP-1 monocytes was investigated by FACS analysis. Relaxin treatment suppressed significantly TNF-α-induced upregulation of VCAM-1 and PECAM, CCR-2, and MCP-1 levels and direct monocyte adhesion to HUVEC. Our findings identify relaxin as a promising inhibitory factor in early vascular inflammation. By attenuating the upregulation of VCAM-1, key adhesion molecule in early vascular inflammation, and of MCP-1, a chemokine pivotal to monocyte recruitment, relaxin decreased initial monocyte-endothelium contact. This may be of relevance for the prevention and treatment of atherosclerosis and of other pro-inflammatory states.
O'Neill, W Charles; Lomashvili, Koba A; Malluche, Hartmut H; Faugere, Marie-Claude; Riser, Bruce L
Pyrophosphate, which may be deficient in advanced renal failure, is a potent inhibitor of vascular calcification. To explore its use as a potential therapeutic, we injected exogenous pyrophosphate subcutaneously or intraperitoneally in normal rats and found that their plasma pyrophosphate concentrations peaked within 15 min. There was a single exponential decay with a half-life of 33 min. The kinetics were indistinguishable between the two routes of administration or in anephric rats. The effect of daily intraperitoneal pyrophosphate injections on uremic vascular calcification was then tested in rats fed a high-phosphate diet containing adenine for 28 days to induce uremia. Although the incidence of aortic calcification varied and was not altered by pyrophosphate, the calcium content of calcified aortas was significantly reduced by 70%. Studies were repeated in uremic rats given calcitriol to produce more consistent aortic calcification and treated with sodium pyrophosphate delivered intraperitoneally in a larger volume of glucose-containing solution to prolong plasma pyrophosphate levels. This maneuver significantly reduced both the incidence and amount of calcification. Quantitative histomorphometry of bone samples after double-labeling with calcein indicated that there was no effect of pyrophosphate on the rates of bone formation or mineralization. Thus, exogenous pyrophosphate can inhibit uremic vascular calcification without producing adverse effects on bone.
Shandalov, Yulia; Egozi, Dana; Freiman, Alina; Rosenfeld, Dekel; Levenberg, Shulamit
Abdominal wall reconstruction following extensive tissue loss is essential and can be achieved using autologous flaps. However, their use is limited due to their inadequate availability and due to post-operative donor site scarification. This work presents a step-by-step technique for fabrication of a vascularized muscle flap, to be applied in full-thickness abdominal wall defect reconstruction. Poly L-lactic acid/poly lactic-co-glycolic acid scaffolds, prepared using a salt leaching technique, were used as the supporting matrix in vitro for simultaneously seeded endothelial cells, fibroblasts and myoblasts. The cell-embedded graft was then implanted around femoral artery and vein vessels, which provided a central blood supply. Vascularization and perfusion were achieved by capillary sprouting from the main host vessel into the graft. A thick and vascularized tissue was formed within one week, and was then transferred as an autologous flap together with its main vessels, to a full-thickness abdominal wall defect. The flap remained viable after transfer and featured sufficient mechanical strength to support the abdominal viscera. Thus, this engineered muscle flap can be used as an alternative source for autologous flaps to reconstruct full-thickness abdominal wall defects.
Frances, Adiukwu; Sandra, Ofori; Lucy, Ugbomah
Over the past two decades, the term vascular cognitive impairment (VCI) has been used to refer to a spectrum of cognitive decline characterized by executive dysfunction, associated with vascular pathology. With 30% of stroke survivors showing cognitive impairments, it is regarded as the most common cause of cognitive impairment. This is a narrative review of available literature citing sources from PubMed, MEDLINE and Google Scholar. VCI has a high prevalence both before and after a stroke and is associated with great economic and caregiver burden. Despite this, there is no standardized diagnostic criteria for VCI. Hypertension has been identified as a risk factor for VCI and causes changes in cerebral vessel structure and function predisposing to lacuna infarcts and small vessel haemorrhages in the frontostriatal loop leading to executive dysfunction and other cognitive impairments. Current trials have shown promising results in the use of antihypertensive medications in the management of VCI and prevention of disease progression to vascular dementia. Prevention of VCI is necessary in light of the looming dementia pandemic. All patients with cardiovascular risk factors would therefore benefit from cognitive screening with screening instruments sensitive to executive dysfunction as well as prompt and adequate control of hypertension. PMID:27354961
Barboni, Barbara; Barbara, Barboni; Martelli, Alessandra; Alessandra, Martelli; Berardinelli, Paolo; Paolo, Berardinelli; Russo, Valentina; Valentina, Russo; Turriani, Maura; Maura, Turriani; Bernabò, Nicola; Nicola, Bernabò; Lucidi, Pia; Pia, Lucidi; Mattioli, Mauro; Mauro, Mattioli
The authors have investigated in the different classes of ovarian follicles the vascular area, the blood vessel distribution, the vascular endothelial growth factor (VEGF) mRNA expression and the VEGF secretion during equine chorionic gonadotropin (eCG) induced follicle growth in prepubertal gilts fed ad libitum or fasted. Immunohistochemistry staining of Von Willebrand factor showed that fasting caused a dramatic increase in the vascular area of medium-large tertiary follicles. The increase involved the two concentric vessel networks and the area between them that, becoming crossed by several anastomosis, modified the whole vessel architecture. Both in situ hybridization and in vitro culture experiments demonstrate that granulosa cells from medium-large follicles are engaged in a copious VEGF production upon eCG stimulation both in gilts fed ad libitum or fasted. More surprisingly, the production of VEGF becomes diffuse amongst theca cells of fasted animals thus recruiting a compartment that in condition of normal feeding regimen appears nearly quiescent. In conclusion, the data presented describe a local angiogenic process that develops in the follicle wall of growing antral follicle in case of acute severe food restriction. The mechanism, essentially confined to follicles that potentially approach ovulation, appears to assume the meaning of a local compensatory mechanism that may help maintaining adequate nutrient delivery to follicles that undergo ovulation.
Azizoglu, D Berfin; Chong, Diana C; Villasenor, Alethia; Magenheim, Judith; Barry, David M; Lee, Simon; Marty-Santos, Leilani; Fu, Stephen; Dor, Yuval; Cleaver, Ondine
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 Â© 2016 Elsevier Inc. All rights reserved.
Gilpin, Victoria; Nichols, W Kirt
Hemodialysis is a life saving treatment for Americans with end stage renal disease. In the last decade, liberal selection of patients treated by hemodialysis has resulted in patients who are substantially older, diabetics, who have higher co-morbidities including extensive atherosclerotic vascular disease. Many of these patients start hemodialysis treatments with a synthetic graft access rather than with their own native vessels. Grafts are appropriate for patients with inadequate vessels for construction of an arterio-venous (A-V) fistulas. The National Kidney Foundation published the Dialysis Outcome Quality Initiative (DOQI) guidelines in 1997, a set of evidenced based guidelines regarding the optimal management of vascular access. One important guideline had been to increase the number of patient dialyzing with Arterio-Venous (A-V) fistulas rather than A-V grafts which are prone to frequent stenosis, thrombosis, and thus are more costly and labor intensive. The prevalence of patient dialyzing with fistulas depends on several factors; timing of the referral, anatomy and adequacy of the patients vessels, type of fistula placed, fistula maturation, minimal accepted dialysis blood flow and patency of the fistula. The management of a vascular access for hemodialysis is a challenging area of practice for those who care for the hemodialysis patient population. The multidisciplinary approach to management of patients with hemodialysis access includes support, education, collaboration and ongoing communication with the multidisciplinary team, patients, and their family members.
Capozzi, Megan E.; Hammer, Sandra S.; McCollum, Gary W.; Penn, John S.
The objective of the present study was to assess the effect of elevating epoxygenated fatty acids on retinal vascular inflammation. To stimulate inflammation we utilized TNFα, a potent pro-inflammatory mediator that is elevated in the serum and vitreous of diabetic patients. In TNFα-stimulated primary human retinal microvascular endothelial cells, total levels of epoxyeicosatrienoic acids (EETs), but not epoxydocosapentaenoic acids (EDPs), were significantly decreased. Exogenous addition of 11,12-EET or 19,20-EDP when combined with 12-(3-adamantane-1-yl-ureido)-dodecanoic acid (AUDA), an inhibitor of epoxide hydrolysis, inhibited VCAM-1 and ICAM-1 expression and protein levels; conversely the diol product of 19,20-EDP hydrolysis, 19,20-DHDP, induced VCAM1 and ICAM1 expression. 11,12-EET and 19,20-EDP also inhibited leukocyte adherence to human retinal microvascular endothelial cell monolayers and leukostasis in an acute mouse model of retinal inflammation. Our results indicate that this inhibition may be mediated through an indirect effect on NFκB activation. This is the first study demonstrating a direct comparison of EET and EDP on vascular inflammatory endpoints, and we have confirmed a comparable efficacy from each isomer, suggesting a similar mechanism of action. Taken together, these data establish that epoxygenated fatty acid elevation will inhibit early pathology related to TNFα-induced inflammation in retinal vascular diseases. PMID:27966642
Lv, Yan-ling; Wu, Ze-zhi; Chen, Li-xue; Wu, Bai-xue; Chen, Lian-lian; Qin, Guang-cheng; Gui, Bei; Zhou, Ji-ying
Tetrandrine is one of the major active ingredients in Menispermaceae Stephania tetrandra S. Moore, and has specific therapeutic effects in ischemic cerebrovascular disease. Its use in vascular dementia has not been studied fully. Here, we investigated whether tetrandrine would improve behavioral and cellular impairments in a two-vessel occlusion rat model of chronic vascular dementia. Eight weeks after model establishment, rats were injected intraperitoneally with 10 or 30 mg/kg tetrandrine every other day for 4 weeks. Behavioral assessment in the Morris water maze showed that model rats had longer escape latencies in training trials, and spent less time swimming in the target quadrant in probe trials, than sham-operated rats. However, rats that had received tetrandrine showed shorter escape latencies and longer target quadrant swimming time than untreated model rats. Hematoxylin-eosin and Nissl staining revealed less neuronal necrosis and pathological damage, and more living cells, in the hippocampus of rats treated with tetrandrine than in untreated model rats. Western blot assay showed that interleukin-1β expression, and phosphorylation of the N-methyl-D-aspartate 2B receptor at tyrosine 1472, were lower in model rats that received tetrandrine than in those that did not. The present findings suggest that tetrandrine may be neuroprotective in chronic vascular dementia by reducing interleukin-1β expression, N-methyl-D-aspartate receptor 2B phosphorylation at tyrosine 1472, and neuronal necrosis. PMID:27127485
Laure-Kamionowska, Milena; Szymanska, Krystyna; Biekiesinska-Figatowska, Monika; Gierowska-Bogusz, Barbara; Michalak, Elżbieta; Klepacka, Teresa
Congenital central nervous tumours form a unique group of neoplasms. They are different from other tumour groups not only due to the onset time but also to their histopathology, anatomic location, and biologic behaviour. Congenital glioblastoma is one of the rarest types of congenital brain tumours and is uncommon in the prenatal period. We report a rare case of congenital glioblastoma detected prenatally by ultrasound examination and magnetic resonance imaging at 26 gestational weeks. Based on MRI findings and consultation of a team of specialists, pregnancy was terminated at 28 weeks. The newborn presented hydrops foetal. The child died shortly after birth due to cardiorespiratory insufficiency. At autopsy a large tumour with a spongy-like appearance was found. The tumour involved nearly the whole right cerebral hemisphere and led to marked hydrocephalus. In the histological and immunohistochemical examination, the tumour presented features of glioblastoma. Neoplastic cells were immunopositive for GFAP, S-100 protein and negative for neuronal markers. Frequent mitoses and high MIB-1 labelling index were seen in the tumour areas. The coexistence of tumour and vascular developmental anomaly was stated. The conglomerates of numerous, distended, thin-walled foetal-like blood vessels were located beside the tumour tissue, which presented disturbance in differentiation and maturation of the vascular net. Such coexistence of malignant glioma with vascular developmental anomaly is unique.
Uh, Jinsoo; Yezhuvath, Uma; Cheng, Yamei; Lu, Hanzhang
To characterize multiple patterns of vascular changes in leukoaraiosis using in vivo magnetic resonance imaging (MRI) techniques. We measured cerebral blood flow (CBF), cerebrovascular reactivity (CVR), and blood-brain-barrier (BBB) leakage in a group of 33 elderly subjects (age: 72.3 +/- 6.8 years, 17 males, 16 females). Leukoaraiosis brain regions were identified in each subject using fluid-attenuated inversion-recovery (FLAIR) MRI. Vascular parameters in the leukoaraiosis regions were compared to those in the normal-appearing white matter (NAWM) regions. Vascular changes in leukoaraiosis were also compared to structural damage as assessed by diffusion tensor imaging. CBF and CVR in leukoaraiosis regions were found to be 39.7 +/- 5.2% (P < 0.001) and 52.5 +/- 11.6% (P = 0.005), respectively, of those in NAWM. In subjects who did not have significant leukoaraiosis, CBF and CVR in regions with high risk for leukoaraiosis showed a slight reduction compared to the other white matter regions. Significant BBB leakage was also detected (P = 0.003) in leukoaraiosis and the extent of BBB leakage was positively correlated with mean diffusivity. In addition, CVR in NAWM was lower than that in white matter of subjects without significant leukoaraiosis. Leukoaraiosis was characterized by reduced CBF, CVR, and a leakage in the BBB. (c) 2010 Wiley-Liss, Inc.
Bonke, Martin; Thitamadee, Siripong; Mähönen, Ari Pekka; Hauser, Marie-Theres; Helariutta, Ykä
Vascular plants have a long-distance transport system consisting of two tissue types with elongated cell files, phloem and xylem. Phloem has two basic cell types, enucleate sieve elements and companion cells. Xylem has various lignified cell types, such as tracheary elements, the differentiation of which involves deposition of elaborate cell wall thickenings and programmed cell death. Until now, little has been known about the genetic control of phloem-xylem patterning. Here we identify the ALTERED PHLOEM DEVELOPMENT (APL) gene, which encodes a MYB coiled-coil-type transcription factor that is required for phloem identity in Arabidopsis. Phloem is established through asymmetric cell divisions and subsequent differentiation. We show that both processes are impaired by a recessive apl mutation. This is associated with the formation of cells that have xylem characteristics in the position of phloem. The APL expression profile is consistent with a key role in phloem development. Ectopic APL expression in the vascular bundle inhibits xylem development. Our studies suggest that APL has a dual role both in promoting phloem differentiation and in repressing xylem differentiation during vascular development.
Miller, Virginia M.; Duckles, Sue P.
The impact of estrogen exposure in preventing or treating cardiovascular disease is controversial. But it is clear that estrogen has important effects on vascular physiology and pathophysiology, with potential therapeutic implications. Therefore, it is the goal of this review to summarize, using an integrated approach, current knowledge of the vascular effects of estrogen, both in humans and in experimental animals. Aspects of estrogen synthesis and receptors, as well as general mechanisms of estrogenic action are reviewed with an emphasis on issues particularly relevant to the vascular system. Recent understanding of the impact of estrogen on mitochondrial function suggests that the longer lifespan of women compared to men may depend in part on the ability of estrogen to decrease production of reactive oxygen species in mitochondria. Mechanisms by which estrogen increases endothelial vasodilator function, promotes angiogenesis and modulates autonomic function are summarized. Key aspects of the relevant pathophysiology of inflammation, atherosclerosis, stroke, migraine and thrombosis are reviewed concerning current knowledge of estrogenic effects. A number of emerging concepts are addressed throughout. These include the importance of estrogenic formulation and route of administration and the impact of genetic polymorphisms, either in estrogen receptors or in enzymes responsible for estrogen metabolism, on responsiveness to hormone treatment. The importance of local metabolism of estrogenic precursors and the impact of timing for initiation of treatment and its duration are also considered. While consensus opinions are emphasized, controversial views are presented in order to stimulate future research. PMID:18579753
Easter, Renee N.; Chan, Qilin; Lai, Barry; Ritman, Erik L.; Caruso, Joseph A.; Qin, Zhenyu
Due to recent progress in analytical techniques, metallomics are evolving from detecting distinct trace metals in a defined state to monitoring the dynamic changes in the abundance and location of trace metals in vitro and in vivo. Vascular metallomics is an emerging field that studies the role of trace metals in vasculature. This review will introduce common metallomics techniques including atomic absorption spectrometry, inductively coupled plasma-atomic emission spectrometry, inductively coupled plasma-mass spectrometry and X-ray fluorescence spectrometry with a summary table to compare these techniques. Moreover, we will summarize recent research findings that have applied these techniques to human population studies in cardiovascular diseases, with a particular emphasis on the role of copper in these diseases. In order to address the issue of interdisciplinary studies between metallomics and vascular biology, we will review the progress of efforts to understand the role of copper in neovascularization. This recent progress in the metallomics field may be a powerful tool to elucidating the signaling pathways and specific biological functions of these trace metals. Finally, we summarize the evidence to support the notion that copper is a dynamic signaling molecule. As a future direction, vascular metallomics studies may lead to the identification of targets for diagnosis and therapy in cardiovascular disease. PMID:19808712
Sureda, A; Batle, J M; Ferrer, M D; Mestre-Alfaro, A; Tur, J A; Pons, A
The aim was to study the effects of scuba diving immersion on plasma antioxidant defenses, nitric oxide production, endothelin-1 and vascular endothelial growth factor levels. 9 male divers performed an immersion at 50 m depth for a total time of 35 min. Blood samples were obtained before diving at rest, immediately after diving, and 3 h after the diving session. Leukocyte counts, plasma 8oxoHG, malondialdehyde and nitrite levels significantly increased after recovery. Activities of lactate dehydrogenase, creatine kinase, catalase and superoxide significantly increased immediately after diving and these activities remained high after recovery. Plasma myeloperoxidase activity and protein levels and extracellular superoxide dismutase protein levels increased after 3 h. Endothelin-1 concentration significantly decreased after diving and after recovery. Vascular endothelial growth factor concentration significantly increased after diving when compared to pre-diving values, returning to initial values after recovery. Scuba diving at great depth activated the plasma antioxidant system against the oxidative stress induced by elevated pO₂ oxygen associated with hyperbaria. The decrease in endothelin-1 levels and the increase in nitric oxide synthesis could be factors that contribute to post-diving vasodilation. Diving increases vascular endothelial growth factor plasma levels which can contribute to the stimulation of tissue resistance to diving-derived oxidative damage.
O’Neill, W. Charles; Lomashvili, Koba A.; Malluche, Hartmut H.; Faugere, Marie-Claude; Riser, Bruce L.
Pyrophosphate, which may be deficient in advanced renal failure, is a potent inhibitor of vascular calcification. To explore its use as a potential therapeutic, we injected exogenous pyrophosphate subcutaneously or intraperitoneally in normal rats and found that their plasma pyrophosphate concentrations peaked within 15 min. There was a single exponential decay with a half-life of 33 min. The kinetics were indistinguishable between the two routes of administration or in anephric rats. The effect of daily intraperitoneal pyrophosphate injections on uremic vascular calcification was then tested in rats fed a high-phosphate diet containing adenine for 28 days to induce uremia. Although the incidence of aortic calcification varied and was not altered by pyrophosphate, the calcium content of calcified aortas was significantly reduced by 70%. Studies were repeated in uremic rats given calcitriol to produce more consistent aortic calcification and treated with sodium pyrophosphate delivered intraperitoneally in a larger volume of glucose-containing solution to prolong plasma pyrophosphate levels. This maneuver significantly reduced both the incidence and amount of calcification. Quantitative histomorphometry of bone samples after double-labeling with calcein indicated that there was no effect of pyrophosphate on the rates of bone formation or mineralization. Thus, exogenous pyrophosphate can inhibit uremic vascular calcification without producing adverse effects on bone. PMID:21124302
Frances, Adiukwu; Sandra, Ofori; Lucy, Ugbomah
Over the past two decades, the term vascular cognitive impairment (VCI) has been used to refer to a spectrum of cognitive decline characterized by executive dysfunction, associated with vascular pathology. With 30% of stroke survivors showing cognitive impairments, it is regarded as the most common cause of cognitive impairment. This is a narrative review of available literature citing sources from PubMed, MEDLINE and Google Scholar. VCI has a high prevalence both before and after a stroke and is associated with great economic and caregiver burden. Despite this, there is no standardized diagnostic criteria for VCI. Hypertension has been identified as a risk factor for VCI and causes changes in cerebral vessel structure and function predisposing to lacuna infarcts and small vessel haemorrhages in the frontostriatal loop leading to executive dysfunction and other cognitive impairments. Current trials have shown promising results in the use of antihypertensive medications in the management of VCI and prevention of disease progression to vascular dementia. Prevention of VCI is necessary in light of the looming dementia pandemic. All patients with cardiovascular risk factors would therefore benefit from cognitive screening with screening instruments sensitive to executive dysfunction as well as prompt and adequate control of hypertension.
Mikati, Abdul G; Khanna, Omaditya; Zhang, Lingjiao; Girard, Romuald; Shenkar, Robert; Guo, Xiaodong; Shah, Akash; Larsson, Henrik BW; Tan, Huan; Li, Luying; Wishnoff, Matthew S; Shi, Changbin; Christoforidis, Gregory A; Awad, Issam A
Patients with the familial form of cerebral cavernous malformations (CCMs) are haploinsufficient for the CCM1, CCM2, or CCM3 gene. Loss of corresponding CCM proteins increases RhoA kinase-mediated endothelial permeability in vitro, and in mouse brains in vivo. A prospective case-controlled observational study investigated whether the brains of human subjects with familial CCM show vascular hyperpermeability by dynamic contrast-enhanced quantitative perfusion magnetic resonance imaging, in comparison with CCM cases without familial disease, and whether lesional or brain vascular permeability correlates with CCM disease activity. Permeability in white matter far (WMF) from lesions was significantly greater in familial than in sporadic cases, but was similar in CCM lesions. Permeability in WMF increased with age in sporadic patients, but not in familial cases. Patients with more aggressive familial CCM disease had greater WMF permeability compared to those with milder disease phenotype, but similar lesion permeability. Subjects receiving statin medications for routine cardiovascular indications had a trend of lower WMF, but not lesion, permeability. This is the first demonstration of brain vascular hyperpermeability in humans with an autosomal dominant disease, as predicted mechanistically. Brain permeability, more than lesion permeability, may serve as a biomarker of CCM disease activity, and help calibrate potential drug therapy. PMID:25966944
Mikati, Abdul G; Khanna, Omaditya; Zhang, Lingjiao; Girard, Romuald; Shenkar, Robert; Guo, Xiaodong; Shah, Akash; Larsson, Henrik B W; Tan, Huan; Li, Luying; Wishnoff, Matthew S; Shi, Changbin; Christoforidis, Gregory A; Awad, Issam A
Patients with the familial form of cerebral cavernous malformations (CCMs) are haploinsufficient for the CCM1, CCM2, or CCM3 gene. Loss of corresponding CCM proteins increases RhoA kinase-mediated endothelial permeability in vitro, and in mouse brains in vivo. A prospective case-controlled observational study investigated whether the brains of human subjects with familial CCM show vascular hyperpermeability by dynamic contrast-enhanced quantitative perfusion magnetic resonance imaging, in comparison with CCM cases without familial disease, and whether lesional or brain vascular permeability correlates with CCM disease activity. Permeability in white matter far (WMF) from lesions was significantly greater in familial than in sporadic cases, but was similar in CCM lesions. Permeability in WMF increased with age in sporadic patients, but not in familial cases. Patients with more aggressive familial CCM disease had greater WMF permeability compared to those with milder disease phenotype, but similar lesion permeability. Subjects receiving statin medications for routine cardiovascular indications had a trend of lower WMF, but not lesion, permeability. This is the first demonstration of brain vascular hyperpermeability in humans with an autosomal dominant disease, as predicted mechanistically. Brain permeability, more than lesion permeability, may serve as a biomarker of CCM disease activity, and help calibrate potential drug therapy.
Dorrello, N. Valerio; Guenthart, Brandon A.; O’Neill, John D.; Kim, Jinho; Cunningham, Katherine; Chen, Ya-Wen; Biscotti, Mauer; Swayne, Theresa; Wobma, Holly M.; Huang, Sarah X. L.; Snoeck, Hans-Willem; Bacchetta, Matthew; Vunjak-Novakovic, Gordana
End-stage lung disease is the third leading cause of death worldwide, accounting for 400,000 deaths per year in the United States alone. To reduce the morbidity and mortality associated with lung disease, new therapeutic strategies aimed at promoting lung repair and increasing the number of donor lungs available for transplantation are being explored. Because of the extreme complexity of this organ, previous attempts at bioengineering functional lungs from fully decellularized or synthetic scaffolds lacking functional vasculature have been largely unsuccessful. An intact vascular network is critical not only for maintaining the blood-gas barrier and allowing for proper graft function but also for supporting the regenerative cells. We therefore developed an airway-specific approach to removing the pulmonary epithelium, while maintaining the viability and function of the vascular endothelium, using a rat model. The resulting vascularized lung grafts supported the attachment and growth of human adult pulmonary cells and stem cell–derived lung-specified epithelial cells. We propose that de-epithelialization of the lung with preservation of intact vasculature could facilitate cell therapy of pulmonary epithelium and enable bioengineering of functional lungs for transplantation. PMID:28875163
Iddings, Jennifer A.
Cerebral blood flow is controlled by two crucial processes, cerebral autoregulation (CA) and neurovascular coupling (NVC) or functional hyperemia. Whereas CA ensures constant blood flow over a wide range of systemic pressures, NVC ensures rapid spatial and temporal increases in cerebral blood flow in response to neuronal activation. The focus of this review is to discuss the cellular mechanisms by which astrocytes contribute to the regulation of vascular tone in terms of their participation in NVC and, to a lesser extent, CA. We discuss evidence for the various signaling modalities by which astrocytic activation leads to vasodilation and vasoconstriction of parenchymal arterioles. Moreover, we provide a rationale for the contribution of astrocytes to pressure-induced increases in vascular tone via the vasoconstrictor 20-HETE (a downstream metabolite of arachidonic acid). Along these lines, we highlight the importance of the transient receptor potential channel of the vanilloid family (TRPV4) as a key molecular determinant in the regulation of vascular tone in cerebral arterioles. Finally, we discuss current advances in the technical tools available to study NVC mechanisms in the brain as it relates to the participation of astrocytes. PMID:23792684