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Outcomes of Saphenous Vein Graft Intervention With and Without Embolic Protection Device: A Comprehensive Review and Meta-AnalysisPaul, Timir, Bhatheja, Samit, Panchal, Hemang, Zheng, Shimin, Banerjee, Subhash, Raso, Sunil V., Guzman, Luis, Beohar, Nirat, Zhao, David, Mehran, Roxana, Mukherjee, Debabrata 01 December 2017 (has links)
Background: Current guidelines give a class I recommendation to use of embolic protection devices (EPD) for saphenous vein graft (SVG) intervention; however, studies have shown conflicting results. The objective of this meta-analysis is to compare all-cause mortality, major adverse cardiovascular events, myocardial infarction (MI), or target vessel revascularization in SVG intervention with and without EPD.
Methods and Results: Literature was searched through October 2016. Eight studies (n=52 893) comparing SVG intervention performed with EPD (n=11 506) and without EPD (n=41 387) were included. There was no significant difference in all-cause mortality (odds ratio [OR], 0.79; confidence interval [CI], 0.55–1.12; P=0.19), major adverse cardiovascular events (OR, 0.73, CI, 0.51–1.05; P=0.09), target vessel revascularization (OR, 1.0; CI, 0.95–1.05; P=0.94), periprocedural MI (OR, 1.12; CI, 0.65–1.90, P=0.69), and late MI (OR, 0.80; CI, 0.52–1.23; P=0.30) between the 2 groups. Sensitivity analysis excluding CathPCI Registry study showed no difference in periprocedural MI, late MI, and target vessel revascularization; however, it favored EPD use in all-cause mortality and major adverse cardiovascular events. Further sensitivity analysis including only observational studies revealed no difference in all-cause mortality, major adverse cardiovascular events, target vessel revascularization, and late MI. Additional analysis after excluding CathPCI Registry study revealed no difference in outcomes.
Conclusions: This study including 52 893 patients suggests no apparent benefit in routine use of EPD during SVG intervention in the contemporary real-world practice. Further randomized clinical trials are needed in current era to evaluate long-term outcomes in routine use of EPD, and meanwhile, current guideline recommendations on EPD use should be revisited.
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Generation and characteriztion of regulatory dendritic cells for the amelioration of acute graft versus host diseaseScroggins, Sabrina Marie 01 December 2013 (has links)
Despite Human Leukocyte Antigen (HLA) matching and use of immunosuppressive drugs, graft-versus-host disease (GVHD) following hematopoietic stem cell transplant (HSCT) is prevalent and often fatal. Additionally, older HSCT recipients experience increased morbidity and mortality. Prophylactic treatment with age-matched syngeneic (recipient strain-derived) cultured regulatory DC (DCreg) has been shown to decrease GVHD-associated mortality in young bone marrow transplanted (BMT) mice. The purpose of this study was to investigate: 1) the potential to generate DCreg from older mice and their subsequent ability to ameliorate GVHD in older BMT mice, 2) the mechanism(s) by which DCreg mitigate GVHD in vivo, 3) the ability of DCreg-treated BMT mice to respond to infectious pathogens, and 4) whether DCreg can be generated under clinically relevant conditions from healthy donor and HSCT recipient PBMCs.
To evaluate the efficacy of DCreg treatment in older mice, complete MHC-mismatched BMT mice were treated with DCreg (hereafter referred to as DCreg-treated BMT mice). Although DCreg treatment ameliorated GVHD in older BMT mice, these mice had increased morbidity and decreased survival compared to their young counterparts.
Following transfer into BMT mice, older DCreg failed to increase inhibitory molecule (PD-L1 and PIR B) expression while significantly upregulating co-stimulatory molecule (CD40 and CD80) expression, conversely young DCreg upregulated inhibitory molecules as well as co-stimulatory molecules. These phenotypic differences between young and older DCreg in vivo provide a potential mechanism for modestly increased morbidity and mortality in older DCreg-treated BMT mice relative to their young counterparts. Indeed, BMT mice treated with DCreg deficient in PD-L1 or PIR B had significantly reduced overall survival, thus both molecules are required for optimal GVHD mitigation.
A murine H1N1 influenza (IAV) infection model was used to assess the donor immune system's capacity to respond to relevant antigens other than those responsible for GVHD. Surprisingly, sub-lethally IAV-infected DCreg-treated BMT mice began to die after d. +21 and all were deceased by d. +25. Virus-specific CD8+ T cell and antibody (Ab) responses were undetectable following primary infection. Interestingly, following a prime-boost infection strategy, DCreg-treated BMT mice survived lethal IAV challenge with no signs of morbidity and had demonstrable IAV-specific Ab and CD8+ T cell responses. Thus a prime-boost IAV infection strategy establishes a protective immune response in the DCreg-treated BMT mice and underscores the potential role vaccination may play in establishing immune competence in DCreg-treated BMT mice.
We investigated whether human DCreg can be generated under clinically relevant conditions: 1) following peripheral blood mononuclear cell (PBMC) cryopreservation, 2) in bovine serum-free media, and 3) from older individuals and HSCT recipients. DCreg were generated from healthy donor and HSCT patient PBMCs isolated from young (old) and older (> 50 years old) individuals by culturing cells in X-vivo serum-free.
Human DCreg generated from both young and older healthy donor PBMCs had comparable numbers, surface molecule phenotype, cytokine production, and able to induce Treg. Cryopreserved and fresh PBMCs generated DCreg with similar phenotypes and cytokine production. DCreg generated from HSCT recipients maintained low co-stimulatory molecule and high inhibitory molecule expression as well as immunosuppressive cytokine production. These studies confirm DCreg can be generated under clinically relevant conditions.
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Efeito do substituto ósseo particulado associado ou não ao MTA na citotoxicidade, resposta tecidual e reparo ósseo em defeitos críticos em calvária de ratos /Machado, Thiago. January 2019 (has links)
Orientador: Wirley Gonçalves Assunção / Resumo: A utilização de biomateriais que visam devolver o volume ósseo perdido após a perda dentária tem se expandido. O osso é um tecido conjuntivo altamente especializado, possuindo dinâmica aposicional onde o equilíbrio entre neoformação e reabsorção envolve a interação de fatores endócrinos, parácrinos e autócrinos. Diversas associações de materiais diversos e substitutos ósseos têm sido estudadas, porém, o MTA (Agregado Trióxido Mineral) ainda carece de informações acerca da sua utilização como substituto ósseo ou em associação com demais substitutos. Assim, o objetivo deste estudo foi avaliar a influência da presença do MTA Angelus Branco® nas proprorções de 5%, 10% e 15% em associação com substituto ósseo de Hidroxiapatita e β- Tricálcio Fosfato na citotoxicidade, resposta tecidual e reparo ósseo, em defeito crítico em calvária de ratos. Para tanto, utilizou-se cultura celular da SAOS-2 para avaliação citológica e ensaio MTT do contato direto e eluentes. Também foram utilizados 112 ratos machos Wistar distribuídos em 7 grupos e avaliados em 2 tempos (7 e 28 dias). Após eutanasiados foram submetidos à microtomografia e por coloração de hematoxilina e eosina para análise histológica e histomorfométrica. A análise da homocedasticidade foi realizada pelo teste Shapiro-Wilk, para distinção dos dados paramétricos e não paramétricos. Para análise dos dados paramétricos, foi realizada análise de variância One-Way (ANOVA One-Way) e realizado o pós-teste de Tukey para os parâmetros micr... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The use of biomaterials that aim to return lost bone volume after tooth loss has expanded. Bone is a highly specialized connective tissue with appositional dynamics where the balance between neoformation and resorption involves the interaction of endocrine, paracrine and autocrine factors. Several associations of different materials and bone substitutes have been studied. However, the MTA (Mineral Trioxide Aggregate) still lacks information about its use as bone substitute or in association with other substitutes. Thus, the aim of this study was to evaluate the influence of presence of MTA Angelus Branco® in the 5%, 10% and 15% proportions in association with Hydroxyapatite and β-Tricalcium Phosphate bone substitute in cytotoxicity, tissue response and bone repair in critical defect in rat calvaria. For this, SAOS-2 cell culture was used for cytological evaluation and MTT assay of direct contact and eluents. We also used 112 male Wistar rats distributed into 7 groups and evaluated at 2 distinct times (7 and 28 days). After euthanasia, the specimens were submitted to microtomography and hematoxylin and eosin staining for histological and histomorphometric analysis. The analysis of homoscedasticity was performed by the Shapiro-Wilk test for distinction of parametric and non-parametric data. For analysis of parametric data, one-way analysis of variance (One-Way ANOVA) was performed and Tukey's post-test was performed for the microtomographic parameters and for the cytotoxicity t... (Complete abstract click electronic access below) / Mestre
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The Lived Experience of In-Center Hemodialysis Patients Receiving Treatment in DeKalb County, GeorgiaCooper, Stacey Deniese 01 January 2017 (has links)
Chronic kidney disease (CKD) is preventable and reversible in the early stages with upstream strategies; however, the number of individuals diagnosed with end-stage renal disease (ESRD) is increasing annually. Although researchers have documented the physiological and psychological stressors associated with hemodialysis (HD), little is known about the effects of in-center HD on the recipients in DeKalb County, Georgia. This study described the experiences of 10 African American HD patients who dialyze in DeKalb County. Using a phenomenological approach, the interviews were transcribed and then analyzed for significant quotes and recurrent themes relevant to receiving HD in DeKalb County. The health belief model was used to identify the perceptions and susceptibilities that formed the lived experiences of the participants. Results showed that 70% of the patients had been diagnosed with hypertension and/or diabetes and that 50% had never heard of ESRD prior to diagnosis. All 10 patients reported never knowing that hypertension and/or diabetes was a major cause of ESRD. The study sought to find common themes related to the perceived threat of ESRD by the participants. This study can be used to implement positive social change by instituting upstream strategies to decrease the prevalence of ESRD or slow the progression of CKD in this population, heightening awareness of this disease in minority communities, and implementing a sustainable health behavior plan to decrease the prevalence of the disease.
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Role of neck angulation and endograft oversizing in folding and its impact on device fixation strengthLin, Kathleen Kei 01 May 2012 (has links)
Objective: To assess neck angulation and endograft oversizing as factors contributing to folding. Endograft folding will then be assessed on its role in endograft fixation strength. Methods: Bench top flow loop experiments were performed with barbless Gore Excluder endovascular grafts (EVG) that were deployed into silicone aorta-AAA models with neck angles of 0, 30, and 60. A total of five oversizings were tested: -7%, 2%, 12%, 24%, and 38% with N= 3 for each oversizing at each neck angle for a total of 45 experiments. Photographs of the stent apex to apex distances were taken for the entire circumference of the device for a total of 8 photos per experiment. Measurements of the apex to apex distance were taken for the top three stent layers and variance for each stent layer was calculated. Variances for all three stent layers were summed to represent the folding metric. The silicone model was then removed from the flow loop and placed on the uniaxial extension tester to for pull out testing to assess impact on attachment strength. Results: Neck angle and oversizing increases folding risk at oversizing ≥12% for 0° and 30° neck angles, and ≥ 2% oversizing for a 60° neck angle. Folding metric comparison between 0° vs. 30° and 0° vs. 60° across all oversizings had statistical significance (Mann-Whitney U, p
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Achievement of Transplantation Tolerance: Novel Approaches and Mechanistic InsightsPidala, Joseph 17 March 2014 (has links)
Current immune suppressive strategies fail to induce donor-recipient immune tolerance after allogeneic hematopoietic cell transplantation. Accordingly, patients suffer morbidity and mortality from graft vs. host disease (GVHD) and prolonged immune suppressive therapy. Biologic insight into transplantation tolerance is needed, and translation of such insight to novel clinical strategies may improve clinical outcomes. We report original investigation at seminal phases of this process including initial prophylactic immune suppression, onset of acute graft vs. host disease, and ultimate immune suppression discontinuation: In a controlled randomized clinical trial, we demonstrate that sirolimus-based immune suppression reduces risk for acute GVHD, ameliorates the severity of subsequent chronic GVHD, and supports reconstitution of functional regulatory T cells. Study of tissue-infiltrating CD4+ T cell subsets in acute GVHD target organs supports a pathogenic role for Th17 cells. Finally, we demonstrate that peripheral blood transcriptional biomarkers provide mechanistic insight into human transplantation tolerance. These data signal progress, and suggest rational translational efforts to achieve transplantation tolerance.
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Radiation curing and grafting of charge transfer complexesZilic, Elvis, University of Western Sydney, College of Health and Science, School of Natural Sciences January 2008 (has links)
Charge transfer (CT) complexes have been used in a number of radiation polymerisation processes including grafting and curing. The complexes studied include donor (D) monomers like vinyl ethers and vinyl acetate (VA) with acceptor (A) monomers such as maleic anhydride (MA). Both UV and EB have been utilised as radiation sources. The complexes are directly grafted to these substrates in the presence of radiation. The complexes yield novel copolymers when radiation cured with concurrent grafting improving the properties of the finished product. The term cure grafting has been proposed for this concurrent grafting process. Studies in basic photografting work to complement the cure grafting have been proposed. The role of solvent in grafting is discussed, particularly the effect of aromatics in photografting to naturally occurring trunk polymers like wool and cellulose. The effect of the double bond molar ratio (DBMR) of the DA components in grafting is examined. The ultraviolet (UV) conditions for gel formation during photografting, hence the importance of homopolymer yields in these processes is reported. A plausible mechanism to explain the results from this photografting work is proposed. The significance of these photografting studies in the related field of curing, especially in UV and ionising radiation (EB) systems, is discussed. EB curing and cure grafting of charge transfer (CT) monomer complexes is investigated. The EB results are compared with UV curing and cure grafting of the same complexes. The work has been extended to include EB/UV curing and cure grafting of thiolene systems. The significance of these results in the potential commercial application of these complexes is discussed. Variables affecting the UV/EB curing and cure grafting of thiolenes on cellulose have been studied. These include effect of varying the type of olefin, increasing the functionality of the thiol, use of acrylate monomers and oligomers in hybrid systems, altering the surface structure of the cellulose and finally the role of air in these processes particularly with EB. Photopolymerisation of the thiol-enes in bulk has also been investigated. The thesis content is based on the published work of 14 research papers over the course of the project. / Doctor of Philosophy (PhD)
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A study of vein graft haemodynamics using computational fluid dynamics techniques.Jackson, Mark John, Clinical School - St Vincent's Hospital, Faculty of Medicine, UNSW January 2007 (has links)
Atherosclerosis, the leading cause of mortality in Western societies, affects large elastic arteries, causing focal deposition of proliferative inflammatory and lipid-laden cells within the artery. Several risk factors have been causally implicated in the ???reaction to injury??? hypothesis first described by Ross in 1969. The ???injury??? sustained by endothelial cells may be either mechanical or chemical. Environmental factors have a role in the production of chemical agents that are injurious to the endothelium. Mechanical stresses such as wall tensile stress are proportional to systemic blood pressure and pulse pressure. Essentially, these systemic pressures are fairly evenly distributed throughout the circulation. However, atherosclerotic lesions characteristically occur at focal sites within the human vasculature; at or near bifurcations, within the ostia of branch arteries and at regions of marked or complex curvature, where local haemodynamic abnormalities occur. The most discussed haemodynamic factor seems to be low or highly oscillating wall shear stress which exists on the outer wall of bifurcations and on the inner aspect of curving vessels. The magnitude of these haemodynamic forces may not be great but the subtleties of their variable spatial distribution may help to explain the multifocal distribution of atherosclerotic plaques. With the altered haemodynamics there is endothelial injury and phenotypic changes in the endothelium result, which in turn lead to endothelial cell dysfunction. These haemodynamic variables are difficult to measure directly in vivo. In this work a novel model is developed utilising human autologous vein bypass grafts as a surrogate vessel for the observation of pathological structural changes in response to altered haemodynamics. The influence of haemodynamic factors (such as wall shear stress) in the remodeling of the vein graft wall and the pathogenesis of Myointimal Hyperplasia (MIH) and resultant wall thickening in femoral bypass grafts is analysed. The haemodynamic determinants of MIH (which have been established in many animal models) are similar to those implicated in atherosclerosis. The accelerated responses of the vein (Intimal hyperplasia develops much more rapidly than atherosclerotic lesions in native vessels) make it an ideal model to expediently examine the hypothesised relationships prospectively in an in vivo setting. Furthermore, the utilisation of in vivo data acquired from non-invasive diagnostic methods (such as Magnetic Resonance Angiography (MRA) and Duplex ultrasound) combined with the application of state-of-the-art Computational Fluid Dynamic (CFD) techniques makes the model essentially non-invasive. The following hypotheses are examined: 1) regions of Low shear and High tensile stress should develop disproportionately greater wall thickening, 2) regions of greater oscillatory blood flow should develop greater wall thickening, and 3) regions of lower wall shear should undergo inward (or negative) remodelling and result in a reduction in vessel calibre. The conclusions reached are that abnormal haemodynamic forces, namely low Time-averaged Wall Shear Stress, are associated with subsequent wall thickening. These positive findings have great relevance to the understanding of vein graft MIH and atherosclerosis. It was also evident that with non-invasive data and CFD techniques, some of the important haemodynamic factors are realistically quantifiable (albeit indirectly). The detection of parameters known to be causal in the development of graft intimal hyperplasia or other vascular pathology may improve ability to predict clinical problems. From a surgical perspective this might be employed to facilitate selection of at-risk grafts for more focused postoperative surveillance and reintervention. On a broader stage the utilisation of such analyses may be useful in predicting individuals at greater risk of developing atherosclerotic deposits, disease progression, and the likelihood of clinical events such as heart attack, stroke and threat of limb loss.
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Activation and effector function of unconventional acute rejection pathways studied in a hepatocellular allograft modelHorne, Phillip Howard, January 2007 (has links)
Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 283-321).
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Evaluation of a Laser Doppler System for Myocardial Perfusion MonitoringFors, Carina January 2007 (has links)
<p>Coronary artery bypass graft (CABG) surgery is a common treatment for patients with coronary artery disease. A potential complication of CABG is myocardial ischemia or infarction. In this thesis, a method - based on laser Doppler flowmetry (LDF) - for detection of intra- and postoperative ischemia by myocardial perfusion monitoring is evaluated.</p><p>LDF is sensitive to motion artifacts. In previous studies, a method for reduction of motion artifacts when measuring on the beating heart has been developed. By using the ECG as a reference, the perfusion signal is measured in intervals during the cardiac cycle where the cardiac motion is at a minimum, thus minimizing the artifacts in the perfusion signal.</p><p>The aim of this thesis was to investigate the possibilities to use the ECG-triggered laser Doppler system for continuous monitoring of myocardial perfusion in humans during and after CABG surgery. Two studies were performed. In the first study, changes in myocardial perfusion during CABG surgery were investigated (n = 13), while the second study focused on postoperative measurements (n = 13). In addition, an ECG-triggering method was implemented and evaluated.</p><p>It was found that the large variations in myocardial perfusion during CABG surgery could be monitored with the ECG-triggered laser Doppler system. Furthermore, a perfusion signal of good quality could be registered postoperatively from the closed chest in ten out of thirteen patients. In eight out of ten patients, a proper signal was obtained also the following morning, i.e., about 20 hours after probe insertion. The results show that respiration and blood pressure can have an influence on the perfusion signal.</p><p>In conclusion, the results indicate that the method is able to detect fluctuations in myocardial perfusion under favourable circumstances. However, high heart rate, abnormal cardiac motion, improper probe attachment and limitations in the ECG-triggering method may result in variations in the perfusion signal that are not related to tissue perfusion.</p> / <p>Varje år utförs omkring 4500 kranskärlsoperationer i Sverige. En allvarlig komplikation som kan uppstå efter operationen är otillräcklig blodförsörjning till hjärtmuskeln. Den här licentiatavhandlingen handlar om utveckling och utvärdering av en metod, baserad på laserdopplerteknik, för att kunna upptäcka nedsatt blodperfusion i hjärtmuskeln på ett tidigt stadium.</p><p>Laserdopplertekniken är känslig för rörelsestörningar. I tidigare studier har en metod för reducering av rörelsestörningar vid mätning på slående hjärta tagits fram. Med EKG:t som referens mäts blodperfusionen i de faser under hjärtcykeln då hjärtats rörelse är som minst, vilket minskar bidraget av rörelsestörningar i blodperfusionssignalen.</p><p>I den här avhandlingen undersöks om metoden kan användas för kontinuerlig övervakning av hjärtmuskelns blodperfusion på patienter under och efter hjärtoperationer. Två studier har genomförts: en där hjärtmuskelns perfusion mättes i olika faser under kranskärlsoperationer och en där mätproben lades in i hjärtmuskeln under operationen och mätningar gjordes under det första dygnet efter operationen.</p><p>Det visade sig vara möjligt att följa förändringar i hjärtmuskelns blodperfusion under operation. Det var även möjligt att registrera en perfusionssignal av god kvalitet efter operationen då bröstkorgen var stängd. Hos åtta av tio patienter erhölls en bra signal även morgonen efter operationen, dvs. ca 20 timmar efter att proben lades in. Resultaten visar också att andning och blodtryck kan ha en påverkan på blodperfusionssignalen.</p><p>Slutsatsen av arbetet är att det går att se variationer i hjärtmuskelns blodperfusion med EKG-triggad laserdoppler under vissa förutsättningar. Signalen är dock i många fall svårtolkad på grund av att t ex hög hjärtfrekvens, onormal hjärtväggsrörelse eller ändrad probposition sannolikt kan ge variationer i perfusionssignalen som inte är relaterade till blodflödesförändringar.</p> / Report code: LIU-TEK-LIC-2007:35.
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