Vascular Damage (vascular + damage)

Distribution by Scientific Domains
Distribution within Medical Sciences

Selected Abstracts

Insulin resistance and endothelial dysfunction: the road map to cardiovascular diseases

Eugenio Cersosimo
Abstract Cardiovascular disease affects approximately 60% of the adult population over the age of 65 and represents the number one cause of death in the United States. Coronary atherosclerosis is responsible for the vast majority of the cardiovascular events, and a number of cardiovascular risk factors have been identified. In recent years, it has become clear that insulin resistance and endothelial dysfunction play a central role in the pathogenesis of atherosclerosis. Much evidence supports the presence of insulin resistance as the fundamental pathophysiologic disturbance responsible for the cluster of metabolic and cardiovascular disorders, known collectively as the metabolic syndrome. Endothelial dysfunction is an important component of the metabolic or insulin resistance syndrome and this is demonstrated by inadequate vasodilation and/or paradoxical vasoconstriction in coronary and peripheral arteries in response to stimuli that release nitric oxide (NO). Deficiency of endothelial-derived NO is believed to be the primary defect that links insulin resistance and endothelial dysfunction. NO deficiency results from decreased synthesis and/or release, in combination with exaggerated consumption in tissues by high levels of reactive oxygen (ROS) and nitrogen (RNS) species, which are produced by cellular disturbances in glucose and lipid metabolism. Endothelial dysfunction contributes to impaired insulin action, by altering the transcapillary passage of insulin to target tissues. Reduced expansion of the capillary network, with attenuation of microcirculatory blood flow to metabolically active tissues, contributes to the impairment of insulin-stimulated glucose and lipid metabolism. This establishes a reverberating negative feedback cycle in which progressive endothelial dysfunction and disturbances in glucose and lipid metabolism develop secondary to the insulin resistance. Vascular damage, which results from lipid deposition and oxidative stress to the vessel wall, triggers an inflammatory reaction, and the release of chemoattractants and cytokines worsens the insulin resistance and endothelial dysfunction. From the clinical standpoint, much experimental evidence supports the concept that therapies that improve insulin resistance and endothelial dysfunction reduce cardiovascular morbidity and mortality. Moreover, interventional strategies that reduce insulin resistance ameliorate endothelial dysfunction, while interventions that improve tissue sensitivity to insulin enhance vascular endothelial function. There is general agreement that aggressive therapy aimed simultaneously at improving insulin-mediated glucose/lipid metabolism and endothelial dysfunction represents an important strategy in preventing/delaying the appearance of atherosclerosis. Interventions that 1 correct carbohydrate and lipid metabolism, 2 improve insulin resistance, 3 reduce blood pressure and restore vascular reactivity, and 4 attenuate procoagulant and inflammatory responses in adults with a high risk of developing cardiovascular disease reduce cardiovascular morbidity and mortality. Whether these benefits hold when the same prevention strategies are applied to younger, high-risk individuals remains to be determined. Copyright 2006 John Wiley & Sons, Ltd. [source]

Hyperthermia in utero due to maternal influenza is an environmental risk factor for schizophrenia

Marshall J. Edwards
ABSTRACT A hypothesis is presented that the association between maternal influenza and other causes of fever during the second trimester of pregnancy and the subsequent development of schizophrenia in the child is due to the damage caused by hyperthermia to the developing amygdalohippocampal complex and associated structures in the fetal brain. Hyperthermia is a known cause of congenital defects of the central nervous system and other organs after sufficiently severe exposures during early organogenesis. The pathogenic mechanisms include death of actively dividing neuroblasts, disruption of cell migration and arborization and vascular damage. In experimental studies, hyperthermia during later stages of central nervous system development also caused damage to the developing brainstem that was associated with functional defects. This damage usually results in hypoplasia of the parts undergoing active development at the time of exposure. Recent studies have shown no evidence of direct invasion of the fetus by the influenza virus. Factors that might interact with hyperthermia include familial liability to schizophrenia, season of birth, maternal nutrition, severe stress and medications used to alleviate the symptoms of fevers. The time of the development of the fetal amygdalohippocampal complex and the changes found in its structure and associated areas of the brain are compatible with the known effects of hyperthermia. [source]

Cells meeting our immunophenotypic criteria of endothelial cells are large platelets

CYTOMETRY, Issue 2 2007
Michiel H. Strijbos
Abstract Background Circulating endothelial cells (CEC) are shed from damaged vasculature, making them a rational choice to serve as surrogate marker for vascular damage. Currently, various techniques and CEC definitions are in use, and their standardization and validation is needed. A flow cytometric single platform assay defining CEC as forward light scatter (FSC)low-to-intermedate, sideward light scatter (SSC)low, CD45,, CD31++ and CD146+ is a promising approach to enumerate CEC because of its simplicity (Mancuso et al., Blood 2001;97:3658,3661). Here, we set out to confirm the endothelial nature of these cells. Methods We isolated cells with a FSClow-to-intermediate, SSClow, CD31++, CD45dim immunophenotype (termed "cells meeting our immunophenotypic criteria for endothelial cells" [CMOIC]) from healthy donors to study the expression of endothelium-associated markers using several techniques. Special attention was paid to reagents identifying the endothelial cell-specific marker CD146. We compared antigen expression patterns of CMOIC with those of the HUVEC endothelial cell line and lymphocytes. Electron microscopy was used to detect the presence of endothelial cell-specific Weibel,Palade bodies in the sorted cells. Results CD146 expression was negative on CMOIC for all tested CD146 mAbs, but positive on HUVEC cells and a minor subset of T lymphocytes. Using flow cytometry, we found no expression of any endothelium-associated marker except for CD31 and CD34. HUVEC cells were positive for all endothelial markers except for CD34. Evaluation of CMOIC morphology showed a homogenous population of cells with a highly irregular nucleus-like structure and positive endothelial immunohistochemistry. CMOIC contained neither nuclei nor DNA. Electron microscopy revealed the absence of a nucleus, the absence of endothelial specific Weibel,Palade bodies, and revealed CMOIC to be large platelets. Conclusion The vast majority of cells with the immunophenotype FSClow-to-intermediate, SSClow, CD45,, CD31++ do not express CD146 and are large platelets rather than endothelial cells. 2007 Clinical Cytometry Society. [source]

Interactions between microvascular and macrovascular disease in diabetes: pathophysiology and therapeutic implications

Andrew J. Krentz
Convention partitions the complications of diabetes into two main subtypes. First are the diabetes-specific microvascular complications of retinopathy, nephropathy and neuropathy; second are the atherothrombotic macrovascular complications that account for the majority of premature deaths. Pathological interactions between microvascular and macrovascular complications, for example, nephropathy and macrovascular disease, are common. Similar mechanisms and shared risk factors drive the development and progression of both small and large vessel disease. This concept has therapeutic implications. Mounting evidence points to the need for multifactorial strategies to prevent vascular complications in subjects with diabetes and/or the metabolic syndrome. We advocate a combined therapeutic approach that addresses small and large vessel disease. Preferential use should be made of drug regimens that (i) maximize vascular protection, (ii) reduce the risk of iatrogenic vascular damage and (iii) minimize the increasing problem of polypharmacy. [source]

,Lipoproteins, glycoxidation and diabetic angiopathy'

Alicia J. Jenkins
Abstract The chronic vascular complications of diabetes (nephropathy, retinopathy and accelerated atherosclerosis) are a major cause of morbidity and premature mortality. In spite of the more widespread availability of intensive diabetes management, approximately one in three people with diabetes develop aggressive complications and over 70% die of atherosclerosis-related diseases. Genetic and acquired factors are likely to be contributory. Potential mediators of vascular damage may include the interrelated processes of lipoprotein abnormalities, glycation, oxidation and endothelial dysfunction. Lipoprotein abnormalities encompass alterations in lipid concentrations, lipoprotein composition and subclass distribution and lipoprotein-related enzymes. Nonenzymatic glycation and oxidative damage to lipoproteins, other proteins and to vascular structures may also be deleterious. As atherosclerosis is a chronic condition commencing in youth, and because clinical events may be silent in diabetes, surrogate measures of vascular disease are important for early identification of diabetic patients with or at high risk of vascular damage, and for monitoring efficacy of interventions. The increasing array of biochemical assays for markers and mediators of vascular damage, noninvasive measures of vascular health, and therapeutic options should enable a reduction in the excessive personal and economic burden of vascular disease in type 1 and type 2 diabetes. Copyright 2004 John Wiley & Sons, Ltd. [source]

Brachial-ankle pulse wave velocity measured automatically by oscillometric method is elevated in diabetic patients with incipient nephropathy

H. Yokoyama
Abstract Aims To examine whether brachial-ankle pulse wave velocity (baPWV), a possible early marker of atherosclerotic vascular damage, is associated with albuminuria in patients with Type 2 diabetes. Methods BaPWV was measured by automatic oscillometric method in 346 Type 2 diabetic patients with normoalbuminuria (a mean level of three times measurements of albumin-to-creatinine (ACR) < 30 g/mg creatinine; n = 200), incipient nephropathy (a mean level of ACR , 30 and < 300 g/mg creatinine; n = 119), and clinical nephropathy (a mean level of ACR , 300 g/mg creatinine; n = 27), and without peripheral vascular disease. Results BaPWV (cm/s) was significantly higher in patients with incipient nephropathy (1722 382) and clinical nephropathy (1763 322) than in patients with normoalbuminuria (1559 343, P < 0.0001, respectively). By univariate analysis it correlated significantly with age (r = 0.44, P < 0.0001), systolic blood pressure (r = 0.55, P < 0.0001), diastolic blood pressure (r = 0.42, P < 0.0001), albuminuria (r = 0.24, P < 0.0001) and HbA1C (r = 0.11, P < 0.05). Albuminuria revealed an independent significant association with baPWV (P < 0.01) after adjustment for age, sex, smoking, BMI, HbA1C, hyperlipidemia, and hypertension. Multiple regression analysis showed age, diastolic blood pressure and albuminuria were independently associated with baPWV (adjusted R2 = 0.42, P < 0.0001). Conclusions The results might indicate a possible link between the pathogenesis of atherosclerosis and diabetic nephropathy. Future studies are needed to clarify the usefulness and its predictable value. [source]

Neuropathological evidence for ischemia in the white matter of the dorsolateral prefrontal cortex in late-life depression

Alan J. Thomas
Abstract Background Signal hyperintensities on magnetic resonance imaging in late-life depression are associated with treatment resistance and poor outcome. These lesions are probably vascular in origin and proposed sites for vascular damage include the dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC). Methods We therefore examined white matter in these areas for microvascular disease and evidence of ischemia using intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1). We obtained postmortem tissue from elderly depressed (n,=,20) and control (n,=,20) subjects and blindly rated microvascular disease and ICAM-1 and VCAM-1 amount using quantitative image analysis in sections of the DLPFC, ACC and occipital cortex (OC; control area). Results We found a significant increase in ICAM-1 in the deep white matter of the DLPFC in the depressed group (p,=,0.01) and a trend towards an increase for VCAM-1 (p,=,0.10). In the gyral white matter there was a trend towards significance for both molecules (p,=,0.07 and 0.10). No differences were found in the ACC or OC or for microvascular disease in any area. Conclusions These findings are consistent with white matter ischemia in the DLPFC and lend support to the ,vascular depression' hypothesis. They implicate the DLPFC as an important site in the pathogenesis of late-life depression and have major implications for the understanding and management of late-life depression and raise the possibility of novel treatments being introduced in the future. Copyright 2002 John Wiley & Sons, Ltd. [source]

How to use laparoscopic surgical instruments safely

Eiji Higashihara
The development of laparoscopic surgery has been accompanied by a rapid increase in the number of laparoscopic surgical procedures carried out in the field of urology. In 2002 laparoscopic nephrectomy was approved for coverage under Japanese national health insurance, and in 2003 there were over 1000 registered cases in which this procedure was carried out. This suggests that laparoscopic nephrectomy, a procedure formerly conducted at only a few institutions, is now spreading to hospitals across Japan. Laparoscopic surgery involves the use of specialized instruments within a restricted field of vision, and risky surgical techniques can potentially result in visceral or vascular damage. In order to promote the use of safe laparoscopic surgery procedures, the Japanese Urological Association and the Japanese Society of Endourology and Extracorporeal Shock Wave Lithotripsy (ESWL) have inaugurated a certification program for urologic laparoscopy. This program not only encourages development in this field of surgery and provides technical certification to ensure appropriate levels of expertise, but also reviews methods for the correct use of instruments such as trocars and hemostats. The purpose of this video is to present correct methods for the use of a variety of laparoscopic instruments, in order to increase the safety of this procedure. The video has been designed to be useful not only for practitioners who are just beginning laparoscopy, but also for those who already have extensive laparoscopic experience. The video discusses five laparoscopic instruments (trocar, electric surgical devices, ultrasonic surgery devices, clips and clip appliers and endo-staplers), and demonstrates their correct use. In addition, animal models are used to illustrate the potential complications that can be associated with some methods of use. [source]

Homocysteine Level and Cognitive Function in Patients with Arterial Disease: The Second Manifestations of ARTerial Disease Study

Fleur van A. Raamt MD
OBJECTIVES: To assess the relationship between total plasma homocysteine (tHcy) level and cognitive function in patients with manifest arterial disease. DESIGN: Cross-sectional. SETTING: Patients with symptomatic cerebrovascular disease, cardiovascular disease, peripheral arterial disease, or abdominal aortic aneurysm included in the Second Manifestations of ARTerial disease study, a single-center, longitudinal study with an extensive screening program at baseline. PARTICIPANTS: Three hundred forty-five consecutively included patients, mean age 59. MEASUREMENTS: The patients underwent an extensive neuropsychological test. The cognitive domains assessed were memory, executive function, attention, and visuoperception and construction. Each raw score was transformed into standardized z-scores, and a sum score for global cognitive function was determined. Risk factors and vascular damage were measured in detail. RESULTS: Linear regression showed that elevated levels of tHcy were related to lower global cognitive function (,=,0.065, 95% confidence interval (CI)=,0.116 to ,0.013) and, more specifically, lower performance on memory (,=,0.078, 95% CI=,0.155 to ,0.002), attention (,=,0.079, 95% CI=,0.163 to ,0.005), and visuoperception and construction (,=,0.125, 95% CI=,0.236 to ,0.014) per standard deviation increase in tHcy (SD=6.4 mol/L), after adjustment for age, sex, educational level, extent of atherosclerosis, and location of vascular disease. Silent cerebral infarcts did not influence this relationship. CONCLUSION: A relationship was found between tHcy levels and cognitive function that was independent of extent and location of arterial disease. The results suggest that vascular mechanisms are not responsible for the relationship between tHcy and cognitive function. [source]

The Amplatzer Duct Occluder II: A New Device for Percutaneous Ductus Arteriosus Closure

Objective: Study the new Amplatzer Duct Occluder II (ADO II). Limitations were encountered with the preexisting devices in nonconical ducts, large ducts, or in small infants. These include failure, residual shunts, protrusion, migration, and vascular damage. Methods: Between June 2008 and March 2009, 20 consecutive patients were enrolled. In cases where different devices were applicable, we favored the use of the ADO II to maximize our experience with this device and prove its superiority. No coils were required in these 20 patients. Results: There were 15 females and 5 males (median age 2 years). ADO II group (n = 16): Immediate complete closure in 75% of the patients, rising to 93.7% at 24 hours. A residual shunt persisted at 3 months in one child. Aortic narrowing from device protrusion was noted in two type E ducts, without any significant gradient, however. ADO I group (n = 4): In two adolescents and in one adult patient, the duct was successfully closed. In a 2-year-old patient with a 6.6 mm type B duct, the ADO I totally obstructed the aortic flow and was retrieved before releasing. The child was sent for surgery. Conclusion: Even though we did not compare the ADO II to other devices, we feel that it has the capacity to substitute most of the coils, and some of the original ADO I indications. Arterial access was sufficient in most patients, but venous delivery is advised in small infants with large or long ducts, to avoid aortic protrusion and residual shunts. [source]

Inhibitory effect of sulfobutyl ether ,-cyclodextrin on DY-9760e-induced cellular damage: In vitro and in vivo studies

Yukihiko Nagase
Abstract The effects of water-soluble ,-cyclodextrin derivatives (,-CyDs), such as 2-hydroxypropyl-,-cyclodextrin (HP-,-CyD) and sulfobutyl ether ,-cyclodextrin (SBE7-,-CyD) on cytotoxicity of DY-9760e (3-[2-[4-(3-chloro-2-methylphenyl)-1-piperazinyl]ethyl]-5,6-dimethoxy-1-(4-imidazolylmethyl)-1H -indazole dihydrochloride 3.5 hydrate) toward human umbilical vein endothelial cells (HUVECs) in vitro and vascular damage of the auricular vein of rabbits by DY-9760e in vivo were investigated. The spectroscopic study revealed that of the four ,-CyDs SBE7-,-CyD forms the most stable inclusion complex in phosphate-buffered saline, probably because of a synergetic effect of hydrophobic and electrostatic interactions. ,-CyDs inhibited DY-9760e-induced cell death toward HUVECs in an order of G2 -,-CyD,<,,-CyD,<,HP-,-CyD,<,SBE7-,-CyD, which was consistent with the order of the magnitude of stability constants. When the DY-9760e solution was infused into the auricular vein of rabbits for 24 h, SBE7-,-CyD suppressed a DY-9760e-induced irritation such as thrombus, desquamation of the endothelium vasculitis, and perivasculitis. The present data indicated that SBE7-,-CyD formed an inclusion complex with DY-9760e in a buffer solution and possessed the protective effect on DY-9760e-induced cytotoxicity toward HUVECs and vascular damage in rabbits. These results suggested potential use of SBE7-,-CyD as a parenteral carrier for DY-9760e. 2003 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 92:2466,2474, 2003 [source]


M.K. Sigrist
SUMMARY Dietary management of hyperphosphatemia and hyperparathyroidism have long been important elements in the clinical management of CKD stage 4 and 5 for the prevention of mineral bone disease. The rationale for phosphate lowering has been further justified, given the accumulating data to support the association of phosphate with vascular damage, in this population who are at high risk of cardiovascular (CV) death. Phosphate is a novel CV risk factor in both CKD and in the general population, and a growing body of literature suggests that high normal serum phosphate may be a risk factor for progression of CKD. Few studies have examined hard outcomes after phosphate lowering. Nonetheless, given the balance of data both in cell, animal and human studies, the use of phosphate lowering strategies at earlier stages of CKD, perhaps even prior to serum phosphate level rising, may well be justified. This review will discuss the complications associated with higher serum phosphate, the potential benefits of early phosphate intervention, practical considerations of low phosphate diets and novel strategies for evaluating these strategies in clinical practice. [source]

Alcohol-Induced Endothelial Changes Are Associated With Oxidative Stress and Are Rapidly Reversed After Withdrawal

ALCOHOLISM, Issue 10 2005
Giorgio Soardo
Abstract: Background: Although heavy alcohol drinkers are at an increased risk of developing cardiovascular events, moderate alcohol intake is associated with reduced incidence of cardiovascular death. This paradox might reflect a dose-related effect of different alcohol intakes on endothelial function and this, in turn, might depend on changes in oxidative stress Methods: We tested the effects of alcohol withdrawal in heavy alcohol consumers and compared the plasma levels of endothelin-1, nitric oxide, plasminogen activator inhibitor-1, von Willebrand factor, malondialdehyde, and intracellular glutathione with those of alcoholics that did not modify their alcohol intake and teetotalers. In human endothelial cells that had been cultured for 2 weeks in the presence of different concentrations of ethanol, we assessed the same parameters after withdrawal of ethanol exposure Results: Alcohol increased the levels of endothelin-1, nitric oxide, and plasminogen activator inhibitor-1 and decreased the levels of von Willebrand factor both in vivo and in vitro. These changes were dose dependent, rapidly reversed after withdrawal of exposure, and associated with the presence of increased oxidative stress as indicated by increased levels of both malondialdehyde and intracellular glutathione. Blockade of oxidative stress by incubation of endothelial cells in the presence of oxidants' scavengers prevented the alcohol-induced functional modifications of the endothelium Conclusions: Alcohol affects endothelial function with an effect that is mediated by an activated oxidative stress and is rapidly reversed after withdrawal. Dose-related endothelial responses to different alcohol intakes might translate in either vascular protection or vascular damage. [source]

Axonal Neuropathy Associated With Cold Agglutinins: A Vasculitic-Ischaemic Neuropathy

G Bezzi
Cold agglutinin (CA) disease is an autoimmune hemolytic process characterized by chronic anemia, hemoglobinuria, cold induced rash, and acrocyanosis of exposed body parts. Although few cases of peripheral neuropathies have been observed in patients with CA, the mechanism of peripheral nervous system involvement is still uncertain. However, similar to other neuropathies due to IgM paraproteinaemia, such as anti-myelin associated glycoprotein, or anti-acidic glycolipid sulphate-3-glucuronyl paragloboside, the direct effect of the antibody on nerve constituents is considered the pathogenetic mechanism causing the demyelinating neuropathy. We report a patient with CA and sensorimotor peripheral neuropathy with electrophysiological and histological findings of a severe acute axonal neuropathy. Pathological findings show vascular damage in the nerve, suggesting a major role for ischaemic/vasculitic pathogenetic mechanism of the peripheral neuropathy in CA. [source]

Histologic evaluation of skin damage after overlapping and nonoverlapping flashlamp pumped pulsed dye laser pulses: A study on normal human skin as a model for port wine stains

Petra H.L. Koster MD
Abstract Background and Objective In the treatment of port wine stains (PWS) with the flashlamp pumped pulsed dye laser (FPPDL), no consensus exists about overlapping of pulses. The advantage of overlapping pulses is homogeneous lightening of the PWS; the risk is redundant tissue damage. The aim of this study was to determine the histopathologic effect on human skin of pulsed dye laser pulses with various degrees of overlap, with normal human skin as a model for PWS. Study Design/Materials and Methods Eighteen healthy white volunteers were irradiated with pulsed dye laser pulses with increasing radiant exposure and with different degrees of overlap. Biopsy samples were taken and histologically analysed. Results Overlapping of pulses on normal human skin enhances depth of vascular damage with approximately 30%. Adjacent pulses also show this effect. We found no histologic signs of serious damage to epidermis or dermal connective tissue by using radiant exposure levels of 6,8 J/cm2, regardless of pulse application. Conclusions Reasoning that the mechanism of tissue injury is comparable for normal and PWS skin, we conclude that it is safe to treat PWS with overlapping FPPDL pulses to achieve homogeneous lightening. Lasers Surg. Med. 28:176,181, 2001. 2001 Wiley-Liss, Inc. [source]

Vascular pathology in dermatomyositis and anatomic relations to myopathology

MUSCLE AND NERVE, Issue 1 2010
Alan Pestronk MD
Abstract The causes of perifascicular myofiber atrophy and capillary pathology in dermatomyositis are incompletely understood. We studied 11 dermatomyositis muscles by histochemistry, immunohistochemistry, and ultrastructure. We found that endomysial capillaries within regions of perifascicular atrophy are not entirely lost, but they have reduced size, endothelial loss, C5b9 complement deposits, and relatively preserved connective tissue molecules and pericytes. In all muscles, the perimysium varies regionally. Some areas contain intermediate-sized vessels. Others are avascular. In dermatomyositis, vascular perimysium contains abnormal vessel fragments, perivascular inflammation, and increased PECAM-1. Perifascicular myofiber atrophy and capillary pathology are concentrated near the avascular perimysium. We conclude that both perimysial intermediate-sized vessels and endomysial capillaries within regions of perifascicular myofiber atrophy are abnormal in dermatomyositis. Capillary damage and myofiber atrophy are concentrated in regions distant from intermediate-sized perimysial vessels. Chronic immune vascular damage and insufficiency in dermatomyositis may cause ischemia, myofiber atrophy, and capillary damage in "watershed" regions of muscle near the avascular perimysium. Muscle Nerve, 2010 [source]

Familial amyloidotic polyneuropathy (ATTR Val30Met) with widespread cerebral amyloid angiopathy and lethal cerebral hemorrhage

Naomi Sakashita
We report an autopsy case of familial amyloidotic polyneuropathy (FAP) with cerebral hemorrhage. A 38-year-old woman with a typical FAP pedigree started developing severe diarrhea and sensori-motor polyneuropathy at the age of 28 years; autonomic nervous system, heart and renal dysfunction manifested themselves in the following years. Genetic analysis revealed a single amino acid substitution at codon 30 of transthyretin (ATTR Val30Met). Ten years after her initial symptoms, the patient died of a sudden convulsive attack and respiratory failure. Autopsy revealed lethal cerebral hemorrhages and uremic lungs. Histochemical and immunohistochemical analyses revealed TTR-derived amyloid protein in every tissue examined, particularly in glomeruli and peripheral vessels. Severe meningo-cerebrovascular amyloidosis was also detected. Because uremia causes oxidative damage to the vascular system and amyloid formation is closely associated with oxidative stress, it is possible that uremic endothelial damage facilitated an unusual cerebral amyloid deposition. In typical FAP (ATTR Val30Met), cerebral amyloid angiopathy does not usually have clinical manifestations. However, cerebral amyloid angiopathy should be considered to explain FAP symptoms when some risk factors such as uremic vascular damage are accompanying features. [source]

Antivascular Tumor Eradication by Hypericin-mediated Photodynamic Therapy,

Bin Chen
ABSTRACT Photodynamic therapy (PDT) with hypericin has been shown to inhibit tumor growth in different tumor models, and tumor vascular damage was suggested to be mainly responsible for the antitumoral effect. Here, we demonstrate tumor vascular damage and its consequence on local tumor control after hypericin-mediated PDT by using both short and long drug,light intervals. Radiation-induced fibrosarcoma-1 tumors were exposed to laser light at either 0.5 or 6 h after a 5 mg/kg dose of hypericin. Tumor perfusion was monitored by fluorescein dye,exclusion assay and by Hoechst 33342 staining of functional blood vessels. Significant reduction in tumor perfusion was found immediately after both PDT treatments. A complete arrest of vascular perfusion was detected by 15 h after the 0.5 h-interval PDT, whereas well-perfused areas could still be found at this time in tumors after the 6 h-interval PDT. A histological study confirmed that primary vascular damage was involved in both PDT treatments. Tumor cells appeared intact shortly after light treatment, degenerated at later hours and became extensively pycnotic at 24 h after the 0.5 h-interval PDT. PDT under this condition led to complete tumor cure. In contrast, significant numbers of viable tumor cells, especially at the tumor periphery, were found histologically at 24 h after the 6 h-interval PDT. No tumor cure was obtained when PDT was performed at this time. Our results strongly suggest that targeting the tumor vasculature by applying short drug,light interval PDT with hypericin might be a promising way to eradicate solid tumors. [source]

006 Efficacy of photochemotherapy and UVA-1 therapy in patients with morphea or lichen sclerosus

K. Ghoreschi
Morphea and lichen sclerosus are inflammatory skin diseases of unknown aetiology. Morphea can be subdivided into plaque morphea, linear morphea and disabling or generalized morphea. In most patients morphea leads to superficial or deep sclerosis of the skin. The characteristic features of lichen sclerosus which often affects the genital area are edema of upper dermis, inflammatory infiltration and hyalinisation to the dermis at advanced stages. Patients with morphea or lichen sclerosus suffer especially from scar formation and morphea may lead to severe disfigurement, contractures and reduction of quality of life. Skin sclerosis seems to be the result of vascular damage, T cell activation and altered connective tissue production. Various therapies have been reported for lichen sclerosus and morphea. Whereas the topical use of ultrapotent corticosteroids is well established for genital lichen sclerosus, immunosuppressive agents are normally not successful in resolving extragenital skin sclerosis. In a retrospective study we confirmed the efficacy of phototherapy in more than 50 patients with morphea. Fourty treatments with 30 J/cm2 UVA-1 or PUVA-bath photochemotherapy resulted in a significant improvement, reduced skin thickness, as determined by high frequency ultrasound and reconstitution of functional mobility of the skin and even the underlying fasciae. In lichen sclerosus phototherapy was successful only in some patients. Thus for lichen sclerosus the use of topical corticosteroids is the first choice therapy, while phototherapy using either PUVA-bath or medium dose UVA-1 are the most effective treatments for morphea. [source]

Macrophage Depletion Suppresses Cardiac Allograft Vasculopathy in Mice

W. H. Kitchens
Cardiac allograft vasculopathy (CAV) is a major source of late posttransplant mortality. Although numerous cell types are implicated in the pathogenesis of CAV, it is unclear which cells actually induce the vascular damage that results in intimal proliferation. Because macrophages are abundant in CAV lesions and are capable of producing growth factors implicated in neointimal proliferation, they are leading end-effector candidates. Macrophages were depleted in a murine heterotopic cardiac transplant system known to develop fulminant CAV lesions. C57BL/6 hearts were transplanted into (C57BL/6 BALB/c)F1 recipients, which then received anti-macrophage therapy with intraperitoneal carrageenan or i.v. gadolinium. Intraperitoneal carrageenan treatment depleted macrophages by 30,80% with minimal effects upon T, B or NK cells as confirmed by flow cytometry and NK cytotoxicity assays. Carrageenan treatment led to a 70% reduction in the development of CAV, as compared to mock-treated controls (p = 0.01), which correlated with the degree of macrophage depletion. Inhibition of macrophage phagocytosis alone with gadolinium failed to prevent CAV. Macrophages may represent the end-effector cells in a final common pathway towards CAV independent of T-cell or B-cell alloreactivity and exert their injurious effects through mechanisms related to cytokine/growth factor production rather than phagocytosis. [source]

Circulating endothelial microparticles as a marker of cerebrovascular disease,

Keun-Hwa Jung MD
Objective Circulating endothelial microparticles (EMPs) have been reported to reflect vascular damage. Detailed profiling of these blood endothelial markers may adumbrate the pathogenesis of stroke or enable determination of the risk for stroke. We investigated EMP profiles in patients at risk for cerebrovascular disease. Methods We prospectively examined 348 consecutive patients: 73 patients with acute stroke and 275 patients with vascular risk factors but no stroke events. We quantified various types of EMPs by flow cytometry using CD31, CD42b, annexin V (AV), and CD62E antibodies in the peripheral blood of patients. This method allowed fractionation of CD31+/CD42b,, CD31+/AV+, and CD62E+ EMPs. Clinical and laboratory factors associated with EMPs were assessed. Results Recent ischemic episodes were found to be more strongly associated with greater CD62E+ EMP levels than with levels of other phenotypes. Increased National Institutes of Health Stroke Scale scores and infarct volumes in acute stroke patients were significantly associated with greater CD62E+ EMP levels. In the risk factor group, patients with extracranial arterial stenosis had greater CD62E+ EMP levels, whereas those with intracranial arterial stenosis had greater CD31+/CD42b, and CD31+/AV+ EMP levels. The ratio of CD62E+ to CD31+/CD42b, or CD31+/AV+ EMP level significantly discriminated extracranial and intracranial arterial stenosis. Interpretation Circulating EMP phenotypic profiles reflect distinct phenotypes of cerebrovascular disease and are markers of vascular pathology and an increased risk for ischemic stroke. Ann Neurol 2009;66:191,199 [source]

Vascular biology and vasculitis

APMIS, Issue 2009
The inflammation of blood vessel walls that is associated with autoimmune disorders characterized by anti-neutrophil cytoplasm antibodies (ANCA) represents dysregulation of normal physiological processes, whereby neutrophils recruited to the vessel wall by cytokine-activated endothelium show destructive behaviours that initiate damage with endothelial apoptosis and denudation. Anti-endothelial cell antibodies may also help to focus and escalate injury. Understanding the molecular mechanisms underlying the interplay between ANCA, aberrant neutrophil behaviour and vascular damage will allow development of more focused therapies. [source]

Involvement of the renin,angiotensin system in the development of vascular damage in a rat model of arthritis: Effect of angiotensin receptor blockers

Takeo Sakuta
Objective To explore the involvement of the renin,angiotensin system (RAS) in the development of vascular damage in adjuvant-induced arthritis (AIA) in rats. Methods Angiotensin II (Ang II; 0.25 or 1.0 mg/kg/day) was infused in control rats and rats with AIA for 21 days, and the impact of systemic inflammation on Ang II,induced hypertension, endothelial dysfunction, and vascular hypertrophy was evaluated. Expression of angiotensin II type 1 receptor (AT1R) and angiotensin-converting enzyme (ACE) in the aortas of rats with AIA were examined by real-time polymerase chain reaction (PCR) and Western blot analyses. Losartan (3 mg/kg/day) or irbesartan (5 mg/kg/day), both of which are AT1R blockers, was administered orally to rats with AIA for 21 days. In situ superoxide production in aortas was assessed according to the fluorogenic oxidation of dihydroethidium to ethidium. The expression and activity of NAD(P)H oxidases in aortas were examined by real-time PCR analysis and lucigenin chemiluminescence assay. Endothelial function in rats with AIA treated in vivo or ex vivo with AT1R blockers was also determined. Results The Ang II,induced hypertensive response, endothelial dysfunction, and vascular hypertrophy were exacerbated in rats with AIA. Expression of AT1R and ACE was increased in the aortas of rats with AIA. Both losartan and irbesartan decreased the levels of superoxide and the expression and activity NAD(P)H oxidases in the aortas of rats with AIA. The endothelial dysfunction in AIA was improved by the in vivo or ex vivo treatment with AT1R blockers. Conclusion The locally activated RAS is involved in the increased vascular oxidative stress and endothelial dysfunction in AIA. Our findings have important implications for clinical approaches to the reduction of cardiovascular risk in patients with rheumatoid arthritis. [source]

Intravenous immunoglobulin and salicylate differentially modulate pathogenic processes leading to vascular damage in a model of Kawasaki disease

Andrew C. Lau
Objective Kawasaki disease (KD) is a multisystem vasculitis affecting children and is characterized by immune activation in the acute stage of disease. Systemic inflammation eventually subsides, although coronary arteritis persists, resulting in aneurysm formation. KD is the leading cause of acquired heart disease among children in North America. Accepted treatment guidelines include high-dose intravenous immunoglobulin (IVIG) and aspirin in the acute phase. Although this therapy is effective, the cellular and molecular mechanisms involved are not clear. The aim of this study was to examine the effect of IVIG and salicylate at each stage of disease development. Methods Using a murine model of KD, we established and validated several in vitro techniques to reflect 3 key steps involved in disease pathogenesis, as follows: thymidine incorporation to evaluate T cell activation, enzyme-linked immunosorbent assay to measure tumor necrosis factor , (TNF,) production, and real-time polymerase chain reaction to examine TNF,-mediated expression of matrix metalloproteinase 9 (MMP-9). Results At therapeutic concentrations, IVIG, but not salicylate, effectively reduced the immune response leading to TNF, expression. Unexpectedly, pharmacologic doses of salicylate were not able to inhibit TNF, production and in fact enhanced its production. Neither drug directly regulated MMP-9 expression but did so only indirectly via modulating TNF,. TNF, activity was a prerequisite for local expression of MMP-9 at the coronary artery. Conclusion Therapeutic concentrations of IVIG and salicylate differentially modulate the expression of TNF, and its downstream effects. Further dissection of the biologic effects of aspirin in acute KD is necessary for the rational design of therapy. [source]

Improved endothelial function after endothelin receptor blockade in patients with systemic sclerosis

Carmine Cardillo
Objective Impaired endothelium-dependent vasodilator function may contribute to vascular damage in patients with systemic sclerosis (SSc). This study was undertaken to investigate whether increased activity of the endothelin 1 (ET-1) system plays a role in the occurrence of endothelial dysfunction in patients with SSc. Methods In 12 patients with SSc (6 with diffuse cutaneous SSc [dcSSc] and 6 with limited cutaneous SSc [lcSSc]), forearm blood flow responses to graded doses of acetylcholine (ACh) and sodium nitroprusside (SNP) given intraarterially were assessed by plethysmography, during infusion of saline and following selective blockade of ETA receptors with BQ-123 (10 nmoles/minute). Results During saline infusion, the vasodilator response to ACh was blunted in patients with SSc as compared with that in healthy controls (P < 0.001), whereas the response to SNP was not different between groups (P = 0.27). The vasodilator effect of ETA receptor antagonism was higher in patients than in controls (P < 0.001), indicating enhanced ET-1,mediated vasoconstriction in SSc. In patients, ETA receptor blockade resulted in a potentiation of the vasodilator response to ACh (P < 0.001 versus saline), but did not affect the response to SNP (P = 0.31). Notably, both the vasodilator effect of ETA receptor antagonism and the improvement in the responsiveness to ACh following BQ-123 infusion were higher in patients with dcSSc than in those with lcSSc (P < 0.01). Conclusion ET-1,dependent vasoconstrictor tone is increased predominantly in the subgroup of SSc patients with dcSSc, in whom acute blockade of ETA receptors was able to improve impaired endothelium-dependent vasodilator function. Our results suggest novel vasculoprotective effects of ETA receptor antagonism and support further exploration of strategies that target the ET-1 pathway in SSc. [source]

Effector CD8+ T cells in systemic sclerosis patients produce abnormally high levels of interleukin-13 associated with increased skin fibrosis

Patrizia Fuschiotti
Objective T lymphocytes play an important role in systemic sclerosis (SSc), a connective tissue disease characterized by inflammation, fibrosis, and vascular damage. While their precise role and antigen specificity are unclear, T cell,derived cytokines likely contribute to the induction of fibrosis. The aim of this study was to establish the role of cytokine dysregulation by T cells in the pathogenesis of SSc. Methods To identify relationships between a specific cytokine, T cell subset, and the disease course, we studied a large cohort of patients with diffuse cutaneous SSc (dcSSc) or limited cutaneous SSc (lcSSc). Using Luminex analysis and intracellular cytokine staining, we analyzed the intrinsic ability of CD4+ and CD8+ T cell subsets to produce cytokines following in vitro activation. Results High levels of the profibrotic type 2 cytokine interleukin-13 (IL-13) were produced following activation of peripheral blood effector CD8+ T cells from SSc patients as compared with normal controls or with patients with rheumatoid arthritis. In contrast, CD4+ T cells showed a lower and more variable level of IL-13 production. This abnormality correlated with the extent of fibrosis and was more pronounced in dcSSc patients than in lcSSc patients. Conclusion Dysregulated IL-13 production by effector CD8+ T cells is important in the pathogenesis of SSc and is critical in the predisposition to more severe forms of cutaneous disease. Our study is the first to identify a specific T cell phenotype that correlates with disease severity in SSc and can be used as a marker of immune dysfunction in SSc and as a novel therapeutic target. [source]

Impairment of endothelial cell differentiation from bone marrow,derived mesenchymal stem cells: New insight into the pathogenesis of systemic sclerosis

P. Cipriani
Objective Systemic sclerosis (SSc) is a disorder characterized by vascular damage and fibrosis of the skin and internal organs. Despite marked tissue hypoxia, there is no evidence of compensatory angiogenesis. The ability of mesenchymal stem cells (MSCs) to differentiate into endothelial cells was recently demonstrated. The aim of this study was to determine whether impaired differentiation of MSCs into endothelial cells in SSc might contribute to disease pathogenesis by decreasing endothelial repair. Methods MSCs obtained from 7 SSc patients and 15 healthy controls were characterized. The number of colony-forming unit,fibroblastoid colonies was determined. After culture in endothelial-specific medium, the endothelial-like MSC (EL-MSC) phenotype was assessed according to the surface expression of vascular endothelial growth factor receptors (VEGFRs). Senescence, chemoinvasion, and capillary morphogenesis studies were also performed. Results MSCs from SSc patients displayed the same phenotype and clonogenic activity as those from controls. In SSc MSCs, a decreased percentage of VEGFR-2+, CXCR4+, VEGFR-2+/CXCR4+ cells and early senescence was detected. After culturing, SSc EL-MSCs showed increased expression of VEGFR-1, VEGFR-2, and CXCR4, did not express CD31 or annexin V, and showed significantly decreased migration after specific stimuli. Moreover, the addition of VEGF and stromal cell,derived factor 1 to cultured SSc EL-MSCs increased their angiogenic potential less than that in controls. Conclusion Our data strongly suggest that endothelial repair may be affected in SSc. The possibility that endothelial progenitor cells could be used to increase vessel growth in chronic ischemic tissues may open up new avenues in the treatment of vascular damage caused by SSc. [source]

Brain damage in pigs produced by impact with a nonpenetrating captive bolt pistol

Objective To assess the effect of impact with a nonpene-trating captive bolt pistol in pigs by studying the resulting traumatic brain injury (TBI) and to compare the pathological changes with those found previously in the brains of sheep using a similar experimental paradigm. Procedure The unrestrained heads of six, anaesthetised, 7- to 8-week-old, Large White pigs were impacted in the temporal region with a nonpenetrating captive bolt pistol. Four hours postimpact, brains were perfusion-fixed with 4% paraformaldehyde. Coronal sections from six levels along the brain were cut and stained with haematoxylin and eosin and immunohistochemically for amyloid precursor protein, a sensitive marker of axonal injury (AI) in the brain after trauma. Results TBI in pigs was characterised only by very mild AI, whereas AI in sheep after captive bolt impact to the same head region was much more severe and widely distributed and often associated with vascular damage such as contusions, subarachnoid and intraparenchymal haemorrhage. Conclusions TBI in pigs was much less severe than in sheep after non-penetrating mechanical impact of similar magnitude, confirming the importance of interspecies differences in determining an appropriate physical method of euthanasia. [source]

Elastosis perforans serpiginosa-like pseudoxanthoma elasticum in a child with severe Moya Moya disease

S. Meyer
Summary A 2-year-old girl with Moya Moya disease who had relapsing cerebrovascular strokes presented with loose skin folds, ,chicken' skin appearance and perforating elastosis serpiginosa-like lesions in the genitocrural region. Histologically, calcified material perforating the epidermis and adjacent short curled and mineralized elastic fibres suggested a variant of pseudoxanthoma elasticum (PXE). As PXE is known to be caused by various mutations in the transmembrane transporter ABCC6 gene, we hypothesized that a novel ABCC6 mutation may underlie this unique combination of PXE and elastopathic vascular damage. Therefore, the complete ABCC6 coding region of the patient and her parents was screened for genetic alterations. No bona fide disease-causing mutation of ABCC6 could be found in the child and in her parents. However, two novel allelic amino acid substitutions (Arg1273Lys and Glu1293Lys; exon 27) were found in the girl and her father, localized in close proximity to the region that codes for the functionally critical second nucleotide-binding fold of ABCC6. Although a causal involvement of these amino acid substitutions could not be proven based on this study, both heterozygote substitutions may possibly have interacted with other undetected recessive maternal ABCC6 changes in the child. To the best of our knowledge, this is the first report of an association between early-onset PXE and severe Moya Moya syndrome possibly related to ABCC6 changes. [source]

Kallikrein inhibitors limit kinin B2 antagonist-induced progression of oedematous to haemorrhagic pancreatitis in rats

T Griesbacher
Background and purpose: Exocrine hyperstimulation with caerulein is an established model for oedematous acute pancreatitis. Prevention of oedema formation by bradykinin B2 receptor antagonists induces a progression to a haemorrhagic course in this model. We have investigated whether increased kallikrein activity in the pancreas is responsible for vascular damage and whether this could be prevented by selective kallikrein inhibitors. Experimental approach: Caerulein was infused i.v. and vascular damage was assessed by histological evaluation and determination of haemoglobin accumulation in the tissue. In addition, oedema formation, tissue and plasma kallikrein (PK) activities and the endogenous kallikrein inhibitors ,1 -antitrypsin (,1 -AT) and ,2 -macroglobulin (,2 -M) were measured. Key results: Haemorrhagic lesions induced by icatibant in caerulein-induced pancreatitis were associated with a reduction in ,1 -AT and ,2 -M in the pancreas and a concomitant augmentation of tissue kallikrein (TK) activity. The TK inhibitor VA999024 (previously FE999024), or its combination with the PK inhibitor VA999026 (previously FE999026), inhibited oedema formation to the same extent but did not induce vascular damage. Furthermore, VA999024 inhibited TK activity. When icatibant was combined with VA999024 and VA999026, progression from oedematous to haemorrhagic pancreatitis was abolished. Conclusions and implications: Reduced oedema formation by B2 antagonists prevented influx of endogenous kallikrein inhibitors and led to an excessive activity of kallikrein in the pancreas leading to vascular damage. This can be prevented by a combined inhibition of both tissue-type and plasma-type kallikrein. Kallikrein inhibitors thus should be further evaluated for their therapeutic potential in preventing haemorrhagic lesions in acute pancreatitis. British Journal of Pharmacology (2008) 155, 865,874; doi:10.1038/bjp.2008.321; published online 11 August 2008 [source]