Device migration after endoluminal abdominal aortic aneurysm repair: Analysis of 113 cases with a minimum follow-up period of 2 years

AbstractPurpose: Device migration (DM) has been shown to cause late failure after endoluminal abdominal aortic aneurysm (AAA) repair. To establish the incidence rate and the predictive factors of distal migration of the proximal portion of the endograft, computed tomographic (CT) scans performed at different time intervals during follow-up examination of 113 patients were reviewed. Patients and Methods: Between April 1997 and March 1999, 148 patients underwent endoluminal AAA repair with a modular endograft with infrarenal fixation (Medtronic-AVE AneuRx, Santa Rosa, Calif) at our unit. CT scans performed at 1, 6, and 12 months after surgery and yearly thereafter were prospectively stored in a computer imaging database. Patient demographics, risk factors, operative details, and follow-up events were prospectively collected. No patients were lost to follow-up examination. Twelve patients died within 2 years of surgery, four patients underwent immediate conversion to open repair, and adequate CT measurements were not feasible in 19 cases, which left 113 patients available for a minimum 2-year assessment and 418 CT scan results reviewed. Two vascular surgeons, blinded to patient identity and history with tested interobserver agreement (κ = 0.64), separately reviewed axial reconstructions of CT scans. DM was defined as changes of 10 mm or more in the distance between the lower renal artery and the first visible portion of the endograft at follow-up examination. Ten possible independent predictors of DM were analyzed with multivariate Cox proportional hazards regression model. Results: One AAA rupture, which was successfully treated, occurred at a mean follow-up period of 28 months (range, 24 to 46 months). Seventeen patients (15%) showed DM. Eight patients (47%) with DM underwent reintervention: a proximal cuff was positioned in six patients and late conversion to open repair was performed in two patients. Of the 10 variables analyzed with Cox proportional hazards regression model, AAA neck enlargement of more than 10% after endoluminal repair (hazard ratio, 7.3; confidence interval, 1.8 to 29.2; P =.004) and preoperative AAA diameter of 55 mm or more (hazard ratio, 4.5; confidence interval, 1.2 to 16.7; P =.02) were positive independent predictors of DM. The probability of DM at 36 months was 27% according to life table analysis. Conclusion: DM occurred in a significant portion of our patients, yet aggressive follow-up examination and a high reintervention rate prevented aneurysm-related death. According to our data, dilatation of the infrarenal aortic neck is an important factor that contributes to the distal migration of stent grafts, and patients with large aneurysms are at high risk for DM. (J Vasc Surg 2002;35:229-35.

A Critical Role for Perivascular Cells in Amplifying Vascular Leakage Induced by Dengue Virus Non-Structural Protein 1

ABSTRACT Dengue is the most prevalent arthropod-borne viral disease affecting humans, with severe dengue typified by potentially fatal microvascular leakage and hypovolemic shock. Blood vessels of the microvasculature are composed of a tubular structure of endothelial cells ensheathed by perivascular cells (pericytes). Pericytes support endothelial cell barrier formation and maintenance through paracrine and contact-mediated signaling and are critical to microvascular integrity. Pericyte dysfunction has been linked to vascular leakage in noncommunicable pathologies such as diabetic retinopathy but has never been linked to infection-related vascular leakage. Dengue vascular leakage has been shown to result in part from the direct action of the secreted dengue virus (DENV) nonstructural protein NS1 on endothelial cells. Using primary human vascular cells, we show here that NS1 also causes pericyte dysfunction and that NS1-induced endothelial hyperpermeability is more pronounced in the presence of pericytes. Notably, NS1 specifically disrupted the ability of pericytes to support endothelial cell function in a three-dimensional (3D) microvascular assay, with no effect on pericyte viability or physiology. These effects are mediated at least in part through contact-independent paracrine signals involved in endothelial barrier maintenance by pericytes. We therefore identify a role for pericytes in amplifying NS1-induced microvascular hyperpermeability in severe dengue and thus show that pericytes can play a critical role in the etiology of an infectious vascular leakage syndrome. These findings open new avenues of research for the development of drugs and diagnostic assays for combating infection-induced vascular leakage, such as severe dengue. IMPORTANCE The World Health Organization considers dengue one of the top 10 global public health problems. There is no specific antiviral therapy to treat dengue virus and no way of predicting which patients will develop potentially fatal severe dengue, typified by vascular leakage and circulatory shock. We show here that perivascular cells (pericytes) amplify the vascular leakage-inducing effects of the dengue viral protein NS1 through contact-independent signaling to endothelial cells. While pericytes are known to contribute to noncommunicable vascular leakage, this is the first time these cells have been implicated in the vascular effects of an infectious disease. Our findings could pave the way for new therapies and diagnostics to combat dengue and potentially other infectious vascular leakage syndromes

Epicatechin-induced conformational changes in β-lactoglobulin B monitored by FT-IR spectroscopy

ABSTRACT: The interaction between whey carrier protein β-lactoglobulin B and (-)-epicatechin, a major dietary flavonoid with a wide range of health-promoting biological activities, was investigated by Fourier transform infrared spectroscopy in physiological conditions. Amide I spectra of epicatechin - β-lactoglobulin complexes, in D(2)O buffer solutions, pD= 6.8, at molar ratios from 0.5:1 to 15:1, were measured by using a cell device specifically created. Changes in secondary structure elements at increasing epicatechin concentrations were quantified. Two different trends were observed for the intensities of β-sheet, random coil, and side chain contributions. At molar ratios ≤2 the β-exposed strand contributions (1625 cm(−1)) increased at the expence of the β-antiparallel sheet band (1637 cm(−1)). At molar ratios >2 the intensities of both β structures slightly decreased. The same behaviour was observed for the side chain contributions (band around 1610 ÷ 1620 cm(−1)). In addition, a conformational transition to a slightly opened structure, followed by aggregate formation at the highest molar ratios, were revealed. The results suggest that binding of epicatechin to β-lactoglobulin in physiological conditions occurs at the surface of the protein molecule, resulting in protein dissociation at molar ratios ≤2 with minor changes in secondary structure. This finding provides further evidence for the possibility of successful use of the protein as a carrier of flavonoids, epicatechin included

Appropriateness of learning curve for carotid artery stenting: An analysis of periprocedural complications

ObjectivesCerebral embolism is the first cause of neurologic complications of carotid artery stenting (CAS). A large debate has been raised to identify the caseload necessary for an appropriate learning curve before systematic use of CAS. This study examined (1) the timing of periprocedural complications during CAS and how these complications vary over time to identify factors that contribute to neurologic morbidity and (2) a sufficient number of procedures for adequate training.MethodsDuring 2001 to 2006, 627 CAS procedures with cerebral protection devices (CPD) were performed in a single vascular surgery center by a team including a vascular surgeon and an interventional radiologist. These represented 38% of a total of 1598 carotid revascularizations performed in the same interval. CAS procedures were divided into two groups according to time interval: the first period, 2001 to 2003, included 195 CAS procedures, and the second period, 2004 to 2006, included 432 CAS procedures. During each CAS procedure, five major steps were considered: phase 1, or the catheterization phase, included the passage of the aortic arch, catheterization of the target vessel, and introduction of a guiding catheter or sheath. Phase 2, or the crossing stenosis phase, included the placement of a CPD. Phase 3, or the stent ballooning phase, included predilation (when indicated), stent implantation, postdilation, and recovery of the protection system. Phase 4, or the early postinterventional phase, included the first 24 hours after leaving the catheterization table. Phase 5, or the late postinterventional phase, included the interval from the first postoperative day to 30 days.ResultsAt 30 days, 10 major strokes (2 of which were fatal) and 1 cardiac death occurred, for an overall major stroke/death rate of 1.75%. Furthermore, 18 minor strokes (2.9%) were recorded. By analyzing the occurrence of major strokes according to the three intraprocedural phases, four occurred in phase 1 and six in phase 3. All strokes but one were ischemic; six were ipsilateral, three were contralateral, and one was posterior. Minor strokes occurred prevalently after the procedure (11 in phase 4, 5 in phase 5, and 1 for phases 1 and 3). Comparing the first with the second interval of the study period, the 30-day major stroke and death rate decreased from 3.1% to 0.9% (P = .047), and the 30-day any stroke and death rate decreased from 8.2% to 2.7% (P = .005). According to multivariate analysis, study interval (hazard ratio, 3.68; 95% confidence interval, 1.49-9.01; P = .005) and age (hazard ratio, 1.06; 95% confidence interval, 1.00-1.12; P = .05) were significant predictors of stroke.ConclusionsA large proportion of major strokes (4/10) from CAS cannot be prevented by using CPD, because these strokes occur during catheterization (phase 1). This finding, together with the significant decrease in the overall stroke/death rate between the first and the last interval of the study period, enhances the importance of an appropriate learning curve that involves a caseload larger than that generally accepted for credentialing. The noticeable number of postprocedural cerebral embolizations leading to minor strokes and occurring in the early and late postinterventional phases (16/18) is likely due to factors less strictly related to the learning-curve effect, such as stent design and medical therapy. Moreover, expertise in selecting material and design of the stents according to different vessel morphology, in association with correct medical treatment, may be useful in reducing the number of minor strokes that occur in the later postinterventional phases of CAS

Deltaic and Coastal Sediments as Recorders of Mediterranean Regional Climate and Human Impact Over the Past Three Millennia

This work was financially supported by the MISTRALS/PaleoMex program and by the Project of Strategic Interest NextData PNR 2011–2013 (www. nextdataproject.it). Lionel Savignan is thanked for his participation in the biomarker analysis. Radiocarbon datings for core KESC9-14 have been funded by Institut Carnot Ifremer-EDROME (grant A0811101). We also thank the Holocene North-Atlantic Gyres and Mediterranean Overturning dynamic through Climate Changes (HAMOC) project for financial support. The biomarker data presented here are available in the supporting information.Peer reviewedPublisher PD

Porcine Organotypic Epicardial Slice Protocol: A Tool for the Study of Epicardium in Cardiovascular Research

The epicardium has recently gained interest in the cardiovascular field due to its capacity to support heart regeneration after ischemic injury. Models to study the epicardium of large animals in vitro are limited and mainly based on epicardial cell isolation/differentiation from stem cells, followed by 2D cells culture. In this method paper, we describe the procedure to obtain and culture 3D organotypic heart slices presenting an intact epicardium, as a novel model to study the epicardial physiology and activation. Epicardial slices are obtained from porcine hearts using a high-precision vibratome and retain a healthy epicardial layer embedded in its native extracellular environment and connected with other cardiac cells (cardiomyocytes, fibroblasts, vascular cells etc.). Epicardial slices can be cultured for 72 h, providing an ideal model for studying the epicardium physiology or perform pharmacological interventions/gene therapy approaches. We also report on methods to assesses the viability and composition of the epicardial slices, and evaluate their architecture in 3D through tissue decoloration. Finally, we present a potential application for a nanomaterial-based gene transfer method for tracking of epicardial cells within the slice. Crucially, given the similarity in morphology and physiology of porcine heart with its human counterpart, our system provides a platform for translational research while providing a clinically relevant and ethical alternative to the use of small animals in this type of research

Um novo ecossistema: florestas urbanas construídas pelo Estado e pelos ativistas

Historicamente, a expansão das cidades resultou na substituição da paisagem natural pela urbana, tendo como consequência a degradação ambiental por meio das mudanças na cobertura do solo, nos sistemas hidrológicos, nos ciclos biogeoquímicos, no clima e na biodiversidade, tornando as cidades especialmente vulneráveis às mudanças climáticas. A reversão desses processos é uma medida que visa a promoção da qualidade de vida nas cidades, na qual a arborização possui um papel fundamental por fornecer uma série de serviços ecossistêmicos valiosos para a promoção da biodiversidade, saúde e bem-estar social. Sendo direito de todos um meio ambiente equilibrado, saudável, de uso comum e essencial à qualidade de vida, o verde urbano é assunto interdisciplinar e de responsabilidade comum e generalizada. Cabe ao poder público a regularização, criação e manutenção dos plantios, promovendo o plantio de árvores a distâncias predeterminadas de acordo com o porte de cada espécie. Porém, os movimentos ativistas se desenvolveram no vácuo da morosidade do poder público seguindo, em geral, o método de adensamento de árvores pautado pelo conceito de sucessão ecológica. Ao promover a restauração dos serviços ecossistêmicos, as duas iniciativas de plantio arbóreo tendem a trazer grandes benefícios às grandes cidades, como São Paulo. Porém, a complexidade da paisagem urbana exige uma avaliação sistêmica dos plantios para definir a sua adequação espacial e otimizar os seus benefícios. O plantio das florestas urbanas não deve ter como objetivo recriar as condições naturais pré-urbanização, mas sim, desenvolver áreas verdes integradas à malha urbana que garantam um ambiente saudável e equilibrado, preservando as interações sociais. Ao visualizar o meio urbano como um ecossistema completo, é possível estabelecer critérios que otimizem os benefícios da arborização urbana. Estes critérios devem ser baseados em conhecimento técnico e científico, levando em conta necessidades sociais, para que o melhor método seja escolhido, caso a caso.Historically, the expansion of cities resulted in the replacement of natural landscape by urban environments, resulting in environmental degradation through changes in soil cover, hydrological systems, biogeochemical cycles, biodiversity, making cities particularly vulnerable to climate changes. Environmental restoration in cities is a measure to promote life quality, and urban forests play a key role in restoring the quality of the urban environment. They provide valuable ecosystem services for maintaining biodiversity, ensuring human health, and social well-being. As everyone has the right to live in a balanced, healthy and common use environment essential to suppor quality of life, urban green areas are an interdisciplinary issue of collective concern. It is the responsibility of the government to regulate, plant and manage urban trees in order to standardize urban afforestation by planting trees at predetermined distances according to the size of each species. However, the vacuum in the greening process left by the State is being filled by activists who, in general, use a different protocol that aims at higher tree density based on the notion of ecological succession. By promoting the restoration of ecosystem services, both initiatives tend to bring significant benefits to large cities such as São Paulo. However, the complexity of the urban landscape requires a systemic evaluation of tree planting to define spatial adequacy and optimize benefits. The planting of urban forests should not aim to recreate pre-urban natural conditions, but rather to develop green areas integrated to the urban network that guarantee a healthy and balanced environment while preserving social interactions. By perceiving the urban environment as a complete ecosystem, it is possible to establish criteria that optimize the benefits of urban afforestation. These criteria should be based on technical and scientific knowledge, and take into account social needs, so that the best method is chosen on a case-by-case basis

Deltaic and Coastal Sediments as Recorders of Mediterranean Regional Climate and Human Impact Over the Past Three Millennia

International audienc

Lunar Gravitational-Wave Antenna

Monitoring of vibrational eigenmodes of an elastic body excited by gravitational waves was one of the first concepts proposed for the detection of gravitational waves. At laboratory scale, these experiments became known as resonant-bar detectors first developed by Joseph Weber in the 1960s. Due to the dimensions of these bars, the targeted signal frequencies were in the kHz range. Weber also pointed out that monitoring of vibrations of Earth or Moon could reveal gravitational waves in the mHz band. His Lunar Surface Gravimeter experiment deployed on the Moon by the Apollo 17 crew had a technical failure rendering the data useless. In this article, we revisit the idea and propose a Lunar Gravitational-Wave Antenna (LGWA). We find that LGWA could become an important partner observatory for joint observations with the space-borne, laser-interferometric detector LISA, and at the same time contribute an independent science case due to LGWA's unique features. Technical challenges need to be overcome for the deployment of the experiment, and development of inertial vibration sensor technology lays out a future path for this exciting detector concept.Comment: 29 pages, 17 figure

Comparative Analysis of Prothrombin Complex Concentrate and Fresh Frozen Plasma in Coronary Surgery

BackgroundRecent studies suggested that prothrombin complex concentrate (PCC) might be more effective than fresh frozen plasma (FFP) to reduce red blood cell (RBC) transfusion requirement after cardiac surgery.MethodsThis is a comparative analysis of 416 patients who received FFP postoperatively and 119 patients who received PCC with or without FFP after isolated coronary artery bypass grafting (CABG).ResultsMixed-effects regression analyses adjusted for multiple covariates and participating centres showed that PCC significantly decreased RBC transfusion (67.2% vs. 87.5%, adjusted OR 0.319, 95%CI 0.136–0.752) and platelet transfusion requirements (11.8% vs. 45.2%, adjusted OR 0.238, 95%CI 0.097–0.566) compared with FFP. The PCC cohort received a mean of 2.7 ± 3.7 (median, 2.0, IQR 4) units of RBC and the FFP cohort received a mean of 4.9 ± 6.3 (median, 3.0, IQR 4) units of RBC (adjusted coefficient, −1.926, 95%CI −3.357–0.494). The use of PCC increased the risk of KDIGO (Kidney Disease: Improving Global Outcomes) acute kidney injury (41.4% vs. 28.2%, adjusted OR 2.300, 1.203–4.400), but not of KDIGO acute kidney injury stage 3 (6.0% vs. 8.0%, OR 0.850, 95%CI 0.258–2.796) when compared with the FFP cohort.ConclusionsThese results suggest that the use of PCC compared with FFP may reduce the need of blood transfusion after CABG.</p