Arterial healing following primary PCI using the Absorb everolimus-eluting bioresorbable vascular scaffold (Absorb BVS) versus the durable polymer everolimus-eluting metallic stent (XIENCE) in patients with acute ST-elevation myocardial infarction: rationale and design of the randomised TROFI II study

AIMS The Absorb bioresorbable vascular scaffold (Absorb BVS) provides similar clinical outcomes compared with a durable polymer-based everolimus-eluting metallic stent (EES) in stable coronary artery disease patients. ST-elevation myocardial infarction (STEMI) lesions have been associated with delayed arterial healing and impaired stent-related outcomes. The purpose of the present study is to compare directly the arterial healing response, angiographic efficacy and clinical outcomes between the Absorb BVS and metallic EES. METHODS AND RESULTS A total of 191 patients with acute STEMI were randomly allocated to treatment with the Absorb BVS or a metallic EES 1:1. The primary endpoint is the neointimal healing (NIH) score, which is calculated based on a score taking into consideration the presence of uncovered and malapposed stent struts, intraluminal filling defects and excessive neointimal proliferation, as detected by optical frequency domain imaging (OFDI) six months after the index procedure. The study will provide 90% power to show non-inferiority of the Absorb BVS compared with the EES. CONCLUSIONS This will be the first randomised study investigating the arterial healing response following implantation of the Absorb BVS compared with the EES. The healing response assessed by a novel NIH score in conjunction with results on angiographic efficacy parameters and device-oriented events will elucidate disease-specific applications of bioresorbable scaffolds.

Idiopathic multifocal choroiditis/punctate inner choroidopathy with acute photoreceptor loss or dysfunction out of proportion to clinically visible lesions.

PURPOSE To report acute/subacute vision loss and paracentral scotomata in patients with idiopathic multifocal choroiditis/punctate inner choroidopathy due to large zones of acute photoreceptor attenuation surrounding the chorioretinal lesions. METHODS Multimodal imaging case series. RESULTS Six women and 2 men were included (mean age, 31.5 ± 5.8 years). Vision ranged from 20/20-1 to hand motion (mean, 20/364). Spectral domain optical coherence tomography demonstrated extensive attenuation of the external limiting membrane, ellipsoid and interdigitation zones, adjacent to the visible multifocal choroiditis/punctate inner choroidopathy lesions. The corresponding areas were hyperautofluorescent on fundus autofluorescence and were associated with corresponding visual field defects. Full-field electroretinogram (available in three cases) showed markedly decreased cone/rod response, and multifocal electroretinogram revealed reduced amplitudes and increased implicit times in two cases. Three patients received no treatment, the remaining were treated with oral corticosteroids (n = 4), oral acyclovir/valacyclovir (n = 2), intravitreal/posterior subtenon triamcinolone acetate (n = 3), and anti-vascular endothelial growth factor (n = 2). Visual recovery occurred in only three cases of whom two were treated. Varying morphological recovery was found in six cases, associated with decrease in hyperautofluorescence on fundus autofluorescence. CONCLUSION Multifocal choroiditis/punctate inner choroidopathy can present with transient or permanent central photoreceptor attenuation/loss. This presentation is likely a variant of multifocal choroiditis/punctate inner choroidopathy with chorioretinal atrophy. Associated changes are best evaluated using multimodal imaging.

Fibrinogen deficiency reduces vascular accumulation of apolipoprotein(a) and development of atherosclerosis in apolipoprotein(a) transgenic mice

To test directly whether fibrin(ogen) is a key binding site for apolipoprotein(a) [apo(a)] in vessel walls, apo(a) transgenic mice and fibrinogen knockout mice were crossed to generate fibrin(ogen)-deficient apo(a) transgenic mice and control mice. In the vessel wall of apo(a) transgenic mice, fibrin(ogen) deposition was found to be essentially colocalized with focal apo(a) deposition and fatty-streak type atherosclerotic lesions. Fibrinogen deficiency in apo(a) transgenic mice decreased the average accumulation of apo(a) in vessel walls by 78% and the average lesion (fatty streak type) development by 81%. Fibrinogen deficiency in wild-type mice did not significantly reduce lesion development. Our results suggest that fibrin(ogen) provides one of the major sites to which apo(a) binds to the vessel wall and participates in the generation of atherosclerosis.

Vascular tumors in livers with targeted inactivation of the von Hippel–Lindau tumor suppressor

von Hippel–Lindau (VHL) disease is a pleomorphic familial tumor syndrome that is characterized by the development of highly vascularized tumors. Homozygous disruption of the VHL gene in mice results in embryonic lethality. To investigate VHL function in the adult we have generated a conditional VHL null allele (2-lox allele) and null allele (1-lox allele) by Cre-mediated recombination in embryonic stem cells. We show here that mice heterozygous for the 1-lox allele develop cavernous hemangiomas of the liver, a rare manifestation of the human disease. Histologically these tumors were associated with hepatocellular steatosis and focal proliferations of small vessels. To study the cellular origin of these lesions we inactivated VHL tissue-specifically in hepatocytes. Deletion of VHL in the liver resulted in severe steatosis, many blood-filled vascular cavities, and foci of increased vascularization within the hepatic parenchyma. These histopathological changes were similar to those seen in livers from mice heterozygous for the 1-lox allele. Hypoxia-inducible mRNAs encoding vascular endothelial growth factor, glucose transporter 1, and erythropoietin were up-regulated. We thus provide evidence that targeted inactivation of mouse VHL can model clinical features of the human disease and underline the importance of the VHL gene product in the regulation of hypoxia-responsive genes in vivo.

Induction of cyclooxygenase-2 by Epstein–Barr virus latent membrane protein 1 is involved in vascular endothelial growth factor production in nasopharyngeal carcinoma cells

Cyclooxygenase-2 (COX-2) is an inducible form of COX and is overexpressed in diverse tumors, raising the possibility of a role for COX-2 in carcinogenesis. In addition, COX-2 contributes to angiogenesis. The Epstein–Barr virus (EBV) oncoprotein, latent membrane protein 1 (LMP1), is detected in at least 70% of nasopharyngeal carcinoma (NPC) and all EBV-infected preinvasive nasopharyngeal lesions. We found that in specimens of LMP1-positive NPC, COX-2 is frequently expressed, whereas LMP1-negative NPC rarely express the enzyme. We next found that expression of LMP1 in EBV-negative nasopharyngeal epithelial cells induced COX-2 expression. Coexpression of IκBα(S32A/S36A), which is not phosphorylated and prevents NF-κB activation, with LMP1 showed that NF-κB is essential for induction of COX-2 by LMP1. We also demonstrate that NF-κB is involved in LMP1-induced cox-2 promoter activity with the use of reporter assays. Two major regions of LMP1, designated CTAR1 and CTAR2, are signal-transducing domains of LMP1. Constructs expressing either CTAR1 or CTAR2 induce COX-2 but to a lesser extent than wild-type LMP1, consistent with the ability of both regions to activate NF-κB. Furthermore, we demonstrate that LMP1-induced COX-2 is functional because LMP1 increased production of prostaglandin E2 in a COX-2-dependent manner. Finally, we demonstrate that LMP1 increased production of vascular endothelial growth factor (VEGF). Treatment of LMP1-expressing cells with the COX-2-specific inhibitor (NS-398) dramatically decreased production of VEGF, suggesting that LMP1-induced VEGF production is mediated, at least in part, by COX-2. These results suggest that COX-2 induction by LMP1 may play a role in angiogenesis in NPC.

Identification of vascular endothelial genes differentially responsive to fluid mechanical stimuli: cyclooxygenase-2, manganese superoxide dismutase, and endothelial cell nitric oxide synthase are selectively up-regulated by steady laminar shear stress.

Early atherosclerotic lesions develop in a topographical pattern that strongly suggests involvement of hemodynamic forces in their pathogenesis. We hypothesized that certain endothelial genes, which exhibit differential responsiveness to distinct fluid mechanical stimuli, may participate in the atherogenic process by modulating, on a local level within the arterial wall, the effects of systemic risk factors. A differential display strategy using cultured human endothelial cells has identified two genes, manganese superoxide dismutase and cyclooxygenase-2, that exhibit selective and sustained up-regulation by steady laminar shear stress (LSS). Turbulent shear stress, a nonlaminar fluid mechanical stimulus, does not induce these genes. The endothelial form of nitric oxide synthase also demonstrates a similar LSS-selective pattern of induction. Thus, three genes with potential atheroprotective (antioxidant, antithrombotic, and antiadhesive) activities manifest a differential response to distinct fluid mechanical stimuli, providing a possible mechanistic link between endothelial gene expression and early events in atherogenesis. The activities of these and other LSS-responsive genes may have important implications for the pathogenesis and prevention of atherosclerosis.

Matrilysin is expressed by lipid-laden macrophages at sites of potential rupture in atherosclerotic lesions and localizes to areas of versican deposition, a proteoglycan substrate for the enzyme.

Certain matrix metalloproteinases (MMP) are expressed within the fibrous areas surrounding acellular lipid cores of atherosclerotic plaques, suggesting that these proteinases degrade matrix proteins within these areas and weaken the structural integrity of the lesion. We report that matrilysin and macrophage metalloelastase, two broad-acting MMPs, were expressed in human atherosclerotic lesions in carotid endarterectomy samples (n = 18) but were not expressed in normal arteries (n = 7). In situ hybridization and immunohistochemistry revealed prominent expression of matrilysin in cells confined to the border between acellular lipid cores and overlying fibrous areas, a distribution distinct from other MMPs found in similar lesions. Metalloelastase was expressed in these same border areas. Matrilysin was present in lipid-laden macrophages, identified by staining with anti-CD-68 antibody. Furthermore, endarterectomy tissue in organ culture released matrilysin. Staining for versican demonstrated that this vascular proteoglycan was present at sites of matrilysin expression. Biochemical studies showed that matrilysin degraded versican much more efficiently than other MMPs present in atherosclerotic lesions. Our findings suggest that matrilysin, specifically expressed in atherosclerotic lesions, could cleave structural proteoglycans and other matrix components, potentially leading to separation of caps and shoulders from lipid cores.

Vascular variant of prion protein cerebral amyloidosis with tau-positive neurofibrillary tangles: the phenotype of the stop codon 145 mutation in PRNP.

Deposition of PrP amyloid in cerebral vessels in conjunction with neurofibrillary lesions is the neuropathologic hallmark of the dementia associated with a stop mutation at codon 145 of PRNP, the gene encoding the prion protein (PrP). In this disorder, the vascular amyloid in tissue sections and the approximately 7.5-kDa fragment extracted from amyloid are labeled by antibodies to epitopes located in the PrP sequence including amino acids 90-147. Amyloid-laden vessels are also labeled by antibodies against the C terminus, suggesting that PrP from the normal allele is involved in the pathologic process. Abundant neurofibrillary lesions are present in the cerebral gray matter. They are composed of paired helical filaments, are labeled with antibodies that recognize multiple phosphorylation sites in tau protein, and are similar to those observed in Alzheimer disease. A PrP cerebral amyloid angiopathy has not been reported in diseases caused by PRNP mutations or in human transmissible spongiform encephalopathies; we propose to name this phenotype PrP cerebral amyloid angiopathy (PrP-CAA).

Investigating the Role of cAMP-Signaling in the Regulation of Vascular Endothelial Cell Adaptive Responses to Fluid Shear Stress

The circulating blood exerts a force on the vascular endothelium, termed fluid shear stress (FSS), which directly impacts numerous vascular endothelial cell (VEC) functions. For example, high rates of linear and undisturbed (i.e. laminar) blood flow maintains a protective and quiescent VEC phenotype. Meanwhile, deviations in blood flow, which can occur at vascular branchpoints and large curvatures, create areas of low, and/or oscillatory FSS, and promote a pro-inflammatory, pro-thrombotic and hyperpermeable phenotype. Indeed, it is known that these areas are prone to the development of atherosclerotic lesions. Herein, we show that cyclic nucleotide phosphodiesterase (PDE) 4D (PDE4D) activity is increased by FSS in human arterial endothelial cells (HAECs) and that this activation regulates the activity of cAMP-effector protein, Exchange Protein-activated by cAMP-1 (EPAC1), in these cells. Importantly, we also show that these events directly and critically impact HAEC responses to FSS, especially when FSS levels are low. Both morphological events induced by FSS, as measured by changes in cell alignment and elongation in the direction of FSS, and the expression of critical FSS-regulated genes, including Krüppel-like factor 2 (KLF2), endothelial nitric oxide synthase (eNOS) and thrombomodlin (TM), are mediated by EPAC1/PDE4D signaling. At a mechanistic level, we show that EPAC1/PDE4D acts through the vascular endothelial-cadherin (VECAD)/ platelet-cell adhesion molecule-1 (PECAM1)/vascular endothelial growth factor receptor 2 (VEGFR2) mechanosensor to activate downstream signaling though Akt. Given the critical role of PDE4D in mediating these effects, we also investigated the impact of various patterns of FSS on the expression of individual PDE genes in HAECs. Notably, PDE2A was significantly upregulated in response to high, laminar FSS, while PDE3A was upregulated under low, oscillatory FSS conditions only. These data may provide novel therapeutic targets to limit FSS-dependent endothelial cell dysfunction (ECD) and atherosclerotic development.

Runx2 and Vascular Calcification

Thesis (Ph.D.)--University of Washington, 2016-06

Association between in-utero exposure to diesel exhaust and N-acetyl-cysteine supplementation in hyperlipidemic pregnant mice and development of atherosclerosis at multiple vascular sites in the offspring

Thesis (Master's)--University of Washington, 2016-06

Higher-level language deficits resulting from left primary cerebellar lesions

Background: Contemporary neuropsychological studies suggest that cerebellar lesions may impact upon higher-level cognitive functioning via mechanisms of crossed cerebello-cerebral diaschisis. Accordingly, right cerebellar lesions have been previously associated with linguistic impairments such as reduced word fluency and agrammatic output. Recently, however, neuroimaging investigations have also identified ipsilateral cerebral hypoperfusion as a consequence of cerebellar lesions, implicating a potential role for the left cerebellum in the mediation of language processes. Aims: The purpose of this research was to investigate the effects of left cerebellar lesions of vascular origin, on general as well as high-level language skills. Methods & Procedures: Linguistic profiles were compiled for five individuals with left primary cerebellar lesions utilising a comprehensive language test battery. Individual scores relevant to each subtest were compared to a group of non-neurologically impaired controls. The criterion for anomalous performance was established as greater than or equal to 1.5 SD below the mean of the control group. Outcomes & Results: The findings of this research suggest that higher-level language deficits may result from left primary cerebellar lesions. All participants demonstrated deficits on measures of word fluency, sentence construction within a set context, producing word definitions, and producing multiple definitions for the same word. Deficits were also noted for several participants on measures of understanding figurative language, forming word associations, identifying and correcting semantic absurdities, and producing synonyms and antonyms. Conclusions: The results presented challenge the notion of a lateralised linguistic cerebellum, supporting a potential role for the left as well as right cerebellar hemispheres in the regulation of language processes, presumably via cerebellar-basal ganglia/thalamo-cortical pathways.

Direct evidence for endothelial vascular endothelial growth factor receptor-1 function in nitric oxide-mediated angiogenesis

Vascular endothelial growth factor-A (VEGF) is critical for angiogenesis but fails to induce neovascularization in ischemic tissue lesions in mice lacking endothelial nitric oxide synthase (eNOS). VEGF receptor-2 (VEGFR-2) is critical for angiogenesis, although little is known about the precise role of endothelial VEGFR-1 and its downstream effectors in this process. Here we have used a chimeric receptor approach in which the extracellular domain of the epidermal growth factor receptor was substituted for that of VEGFR-1 (EGLT) or VEGFR-2 (EGDR) and transduced into primary cultures of human umbilical vein endothelial cells (HUVECs) using a retroviral system. Activation of HUVECs expressing EGLT or EGDR induced rapid phosphorylation of eNOS at Ser1177, release of NO, and formation of capillary networks, similar to VEGF. Activation of eNOS by VEGFR-1 was dependent on Tyr794 and was mediated via phosphatidylinositol 3-kinase, whereas VEGFR-2 Tyr951 was involved in eNOS activation via phospholipase Cgamma1. Consistent with these findings, the VEGFR-1-specific ligand placenta growth factor-1 activated phosphatidylinositol 3-kinase and VEGF-E, which is selective for VEGFR-2-activated phospholipase Cgamma1. Both VEGFR-1 and VEGFR-2 signal pathways converged on Akt, as dominant-negative Akt inhibited the NO release and in vitro tube formation induced following activation of EGLT and EGDR. The identification Tyr794 of VEGFR-1 as a key residue in this process provides direct evidence of endothelial VEGFR-1 in NO-driven in vitro angiogenesis. These studies provide new sites of modulation in VEGF-mediated vascular morphogenesis and highlight new therapeutic targets for management of vascular diseases.

Atividade eletroencefalográfica de pacientes com acidente vascular cerebral na aprendizagem motora de um jogo baseado em realidade virtual

Stroke is the leading cause of long-term disability among adults and motor relearning is essential in motor sequelae recovery. Therefore, various techniques have been proposed to achieve this end, among them Virtual Reality. The aim of the study was to evaluate electroencephalographic activity of stroke patients in motor learning of a virtual reality-based game. The study included 10 patients with chronic stroke, right-hande; 5 with left brain injury (LP), mean age 48.8 years (± 4.76) and 5 with injury to the right (RP), mean age 52 years (± 10.93). Participants were evaluated for electroencephalographic (EEG) activity and performance while performing 15 repetitions of darts game in XBOX Kinect and also through the NIHSS, MMSE, Fugl-Meyer and the modified Ashworth scale. Patients underwent a trainning with 45 repetitions of virtual darts game, 12 sessions in four weeks. After training, patients underwent reassessment of EEG activity and performance in virtual game of darts (retention). Data were analyzed using ANOVA for repeated measures. According to the results, there were differences between the groups (PD and PE) in frequencies Low Alpha (p = 0.0001), High Alpha (p = 0.0001) and Beta (p = 0.0001). There was an increase in alpha activation powers and a decrease in beta in the phase retention of RP group. In LP group was observed increased alpha activation potency, but without decrease in beta activation. Considering the asymmetry score, RP group increased brain activation in the left hemisphere with the practice in the frontal areas, however, LP group had increased activation of the right hemisphere in fronto-central areas, temporal and parietal. As for performance, it was observed a decrease in absolute error in the game for RP group between assessment and retention (p = 0.015), but this difference was not observed for LP group (p = 0.135). It follows then that the right brain injury patients benefited more from darts game training in the virtual environment with respect to the motor learning process, reducing neural effort in ipsilesionais areas and errors with the practice of the task. In contrast, patients with lesions in left hemisphere decrease neural effort in contralesionais areas important for motor learning and showed no performance improvements with practice of 12 sessions of virtual dart game. Thus, the RV can be used in rehabilitation of stroke patients upper limb, but the laterality of the injury should be considered in programming the motor learning protocol.

Easy preoperative planning of deeply located brain lesions using external skin reference and 3-Dimensional surface MRI

Open skull surgery of deeply located intracerebral lesions requires precise determination of the treatment area in 3-dimensional (3-D) space. 3-D MRI can give important additional information in presurgical determination of the surgical approach to the target, taking into account highly functional brain areas and important vascular structures. The day before surgery, a grid composed of 9 tubings intersecting at 90° at 1 cm intervals and filled with a Q1SO4 solution is firmly attached to the skin of the patient’s head in the presumed region of the craniotomy. A 3-D turbo-FLASH sequence is then performed in the sagittal plane after intravenous Gd-DOTA injection on a IT Magnetom. 3-D surface reconstruction of the cortical gyri and sulci is performed. Once the gyri are identified, the 3-D program is then implemented in order to perform a color display of the cortical veins and of the tumor boundaries. The surgical access is then chosen by the surgeon, taking into account highly functional areas. Finally, the boundaries of the tumor are projected on the cortex reconstruction and on the external reference placed on the skin. The entry place for surgery as well as the size of craniotomy are drawn on the skin and the tubed grid is removed. The accuracy of this method tested in 9 patients with deeply located brain tumors or arteriovenous malformations was very satisfactory. In daily practice, this method is a valuable technique providing important clinical information in determining the shortest and safest way through the brain tissue, decreasing possible functional deficit and reducing craniotomy size in cases of difficult to access deep brain areas. Our method does not require a stereotactic frame permanently fixed to the head of the patient during surgery. © 1994 S. Karger AG, Basel.