907 resultados para Aorte--Calcification


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AIM: To evaluate the pulp and periodontal healing of laterally luxated permanent teeth. MATERIAL AND METHODS: Patients presenting with lateral luxation of permanent teeth during 2001-2002 were enrolled in this clinical study. Laterally luxated teeth were repositioned and splinted with a TTS/composite resin splint for 4 weeks. Immediate (prophylactic) root-canal treatment was performed in severely luxated teeth with radiographically closed apices. All patients received tetracycline for 10 days. Re-examinations were performed after 1, 2, 3, 6, 12 and 48 months. RESULTS: All 47 laterally luxated permanent teeth that could be followed over the entire study period survived. In 10 teeth (21.3%), a prophylactic root-canal treatment was performed within 2 weeks following injury. The remaining 37 teeth showed the following characteristics at the 4-year re-examination: 19 teeth (51.4%) had pulp survival (no clinical or radiographic signs or symptoms), nine teeth (24.3%) presented with pulp canal calcification, and pulp necrosis was seen in another nine teeth (24.3%), within the first year after trauma. None of the teeth with a radiographically open apex at the time of lateral luxation showed complications. External root resorption was only seen in one tooth. CONCLUSIONS: Laterally luxated permanent teeth with incomplete root formation have a good prognosis, with all teeth surviving in this study. The most frequent complication was pulp necrosis that was only seen in teeth with closed apices.

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Accelerated vascular calcification is a severe complication of chronic kidney disease contributing to high morbidity and mortality in patients undergoing renal replacement therapy. Sodium thiosulfate is increasingly used for the treatment of soft tissue calcifications in calciphylaxis. Therefore, we determined whether it also prevents development of vascular calcifications in chronic kidney disease. We found that uremic rats treated by thiosulfate had no histological evidence of calcification in the aortic wall whereas almost three-fourths of untreated uremic rats showed aortic calcification. Urinary calcium excretion was elevated and the calcium content of aortic, heart, and renal tissue was significantly reduced in the thiosulfate-treated compared to non-treated animals. Sodium thiosulfate treatment transiently lowered plasma ionized calcium and induced metabolic acidosis. It also lowered bone strength in the treated animals compared to their normal controls. Hence, sodium thiosulfate prevented vascular calcifications in uremic rats, likely by enhancing acid- and/or chelation-induced urinary calcium loss. The negative impact on rat bone integrity necessitates a careful risk-benefit analysis before sodium thiosulfate can be used in individual human patients.

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This research focused on the to modification of the surface structure of titanium implants with nanostructured morphology of TiO2 nanotubes and studied the interaction of nanotubes with osteoblast cells to understand the parameters that affect the cell growth. The electrical, mechanical, and structural properties of TiO2 nanotubes were characterized to establish a better understanding on the properties of such nanoscale morphological structures. To achieve the objectives of this research work I transformed the titanium and its alloys, either in bulk sheet form, bulk machined form, or thin film deposited on another substrate into a surface of titania nanotubes using a low cost and environmentally friendly process. The process requires only a simple electrolyte, low cost electrode, and a DC power supply. With this simple approach of scalable nanofabrication, a typical result is nanotubes that are each approximately 100nm in diameter and have a wall thickness of about 20nm. By changing the fabrication parameters, independent nanotubes can be fabricated with open volume between them. Titanium in this form is termed onedimensional since electron transport is narrowly confined along the length of the nanotube. My Ph.D. accomplishments have successfully shown that osteoblast cells, the cells that are the precursors to bone, have a strong tendency to attach to the inside and outside of the titanium nanotubes onto which they are grown using their filopodia – cell’s foot used for locomotion – anchored to titanium nanotubes. In fact it was shown that the cell prefers to find many anchoring sites. These sites are critical for cell locomotion during the first several weeks of maturity and upon calcification as a strongly anchored bone cell. In addition I have shown that such a surface has a greater cell density than a smooth titanium surface. My work also developed a process that uses a focused and controllably rastered ion beam as a nano-scalpel to cut away sections of the osteoblast cells to probe the attachment beneath the main cell body. Ultimately the more rapid growth of osteoblasts, coupled with a stronger cell-surface interface, could provide cost reduction, shorter rehabilitation, and fewer follow-on surgeries due to implant loosening.

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PURPOSE: We report the clinical, morphological, and ultrastructural findings of 13 consecutively explanted opacified Hydroview(R) (hydrogel) intraocular lenses (IOLs). Our purpose was to provide a comprehensive account on the possible factors involved in late postoperative opacification of these IOLs. PATIENTS AND METHODS: Thirteen consecutive opacified hydrogel IOLs (Hydroview H 60 M, Bausch ; Lomb) were explanted due to the significant visual impairment they caused. The IOLs underwent macroscopical examination, transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and electrophoresis for protein detection. Three unused control Hydroview IOLs served for comparison. RESULTS: Macroscopical examination showed a diffuse or localized grey-whitish opacification within the IOL optic. TEM confirmed the presence of lesions inside the optic in all the explanted IOLs and revealed 3 patterns of deep deposits: a) diffuse, thick, granular, electron-dense ones; b) small, thin, lattice-like ones, with prominent electron-lucent areas; and c) elongated electron-dense formations surrounded by electron-lucent halos. SEM showed surface deposits on four IOLs. EDS revealed oxygen and carbon in all IOLs and documented calcium, phosphorus, silicon and/or iron in the deposits. Two of the patients with iron in their IOLs had eye surgery prior to their phacoemulsification. Iron correlated well with the second TEM pattern of deep lesions, whereas calcium with the third TEM pattern. No protein bands were detected on electrophoresis. Control lenses did not show any ultrastructural or chemical abnormality. CONCLUSIONS: The present study supports the presence of chemical alterations inside the polymer of the optic in late postoperative opacification of Hydroview IOLs. This opacification does not follow a unique pathway but may present under different ultrastructular patterns depending on the responsible factors. Mechanical stress during surgery may initiate a sequence of events where ions such as calcium, phosphorus, silicon, and/or iron, participate in a biochemical cascade that leads to gradual alteration of the polymer network. Intraocular inflammation due to previous operation may be a factor inducing opacification through increase of iron-binding capacity in the aqueous humour. Calcification accounts only partially for the opacification noted in this type of IOL.

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Two technical solutions using single or dual shot offer different advantages and disadvantages for dual energy subtraction. The principles of these are explained and the main clinical applications with results are demonstrated. Elimination of overlaying bone and proof or exclusion of calcification are the primary aims of energy subtraction chest radiography, offering unique information in different clinical situations.

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The indications for screening and TSH threshold levels for treatment of subclinical hypothyroidism have remained a clinical controversy for over 20 years. Subclinical thyroid dysfunction is a common finding in the growing population of older adults, occurring in 10–15% among those age 65 and older, and may contribute to multiple common problems of older age, including cardiovascular disease, muscular impairment, mood problems, and cognitive dysfunction (1). In 2004, both the U.S. Preventive Services Task Force (2) and a clinical consensus group of experts (3) concluded that the existing evidence about the association between subclinical hypothyroidism and cardiovascular risks, primarily cross-sectional or case-control studies (4), was insufficient. For example, a frequently cited analysis from the Rotterdam study found a cross-sectional association between subclinical hypothyroidism and atherosclerosis, as measured by abdominal aortic calcification (odds ratio, 1.7; 95% confidence interval [CI], 1.1–2.6) and prevalent myocardial infarction (MI) (odds ratio, 2.3; 95% CI, 1.3–4.0) (5). Conversely, the prospective part of this study included only 16 incident MIs; the hazard ratio (HR) for subclinical hypothyroidism was 2.50, with broad 95% CIs (0.70–9.10). Potential mechanisms for the associations with cardiovascular diseases among adults with subclinical hypothyroidism include elevated cholesterol levels, inflammatory markers, raised homocysteine, increased oxidative stress, insulin resistance, increased systemic vascular resistance, arterial stiffness, altered endothelial function, and activation of thrombosis and hypercoagulability that have all been reported to be associated with subclinical hypothyroidism (1, 6).

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BACKGROUND Little is known about the pathologic changes in the epidural space after intervertebral disk (IVD) extrusion in the dog. OBJECTIVES To analyze the pathology of the epidural inflammatory response, and to search for correlations between this process and clinical findings. METHODS Clinical data from 105 chondrodystrophic (CD) and nonchondrodystrophic (NCD) dogs with IVD extrusion were recorded. Epidural material from these dogs was examined histopathologically and immunohistochemically. Using statistical analysis, we searched for correlations between severity of epidural inflammation and various clinical and pathologic variables. RESULTS Most dogs exhibited an epidural inflammatory response, ranging from acute invasion of neutrophils to formation of chronic granulation tissue. The mononuclear inflammatory infiltrates consisted mostly of monocytes and macrophages and only few T and B cells. Surprisingly, chronic inflammatory patterns also were found in animals with an acute clinical history. Severity of the epidural inflammation correlated with degree of the epidural hemorrhage and nucleus pulposus calcification (P = .003 and .040), but not with age, chondrodystrophic phenotype, neurologic grade, back pain, pretreatment, or duration. The degree of inflammation was statistically (P = .021) inversely correlated with the ability to regain ambulation. CONCLUSION AND CLINICAL IMPORTANCE Epidural inflammation occurs in the majority of dogs with IVD extrusion and may develop long before the onset of clinical signs. Presence of calcified IVD material and hemorrhage in the epidural space may be the triggers of this lesion rather than an adaptive immune response to the nucleus pulposus as suggested in previous studies. Because epidural inflammation may affect outcome, further research is warranted.

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Check-up is a frequent motivation for patients to see their general practitioner. The challenge lies in the choice of screening tools to accomplish an efficient, individual and age-adapted approach. In this article we review evidence-based screening methods, whose efficacy has been demonstrated by randomized clinical trials, as well as their application in clinical practice. While cardiovascular check-up has a high grade of evidence for nearly all patients, counselling to lifestyle change except for smoking cessation has been proved with lower evidence. In contrast, relatively new is the fact that ultrasound to screen for an abdominal aortic aneurysm is useful among men smokers or past smokers between 65 and 75 years old.

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Purpose: To quantify the in vivo deformations of the popliteal artery during leg flexion in subjects with clinically relevant peripheral artery disease (PAD). Methods: Five patients (4 men; mean age 69 years, range 56–79) with varying calcification levels of the popliteal artery undergoing endovascular revascularization underwent 3-dimensional (3D) rotational angiography. Image acquisition was performed with the leg straight and with a flexion of 70°/20° in the knee/hip joints. The arterial centerline and the corresponding branches in both positions were segmented to create 3D reconstructions of the arterial trees. Axial deformation, twisting, and curvatures were quantified. Furthermore, the relationships between the calcification levels and the deformations were investigated. Results: An average shortening of 5.9%±2.5% and twist rate of 3.8±2.2°/cm in the popliteal artery were observed. Maximal curvatures in the straight and flexed positions were 0.12±0.04 cm−1 and 0.24±0.09 cm−1, respectively. As the severity of calcification increased, the maximal curvature in the straight position increased from 0.08 to 0.17 cm−1, while an increase from 0.17 to 0.39 cm−1 was observed for the flexed position. Axial elongations and arterial twisting were not affected by the calcification levels. Conclusion: The popliteal artery of patients with symptomatic PAD is exposed to significant deformations during flexion of the knee joint. The severity of calcification directly affects curvature, but not arterial length or twisting angles. This pilot study also showed the ability of rotational angiography to quantify the 3D deformations of the popliteal artery in patients with various levels of calcification.

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BACKGROUND The effectiveness and durability of endovascular revascularization therapies for chronic critical limb ischemia (CLI) are challenged by the extensive burden of infrapopliteal arterial disease and lesion-related characteristics (e.g., severe calcification, chronic total occlusions), which frequently result in poor clinical outcomes. While infrapopliteal vessel patency directly affects pain relief and wound healing, sustained patency and extravascular care both contribute to the ultimate "patient-centric" outcomes of functional limb preservation, mobility and quality of life (QoL). METHODS/DESIGN IN.PACT DEEP is a 2:1 randomized controlled trial designed to assess the efficacy and safety of infrapopliteal arterial revascularization between the IN.PACT Amphirion™ paclitaxel drug-eluting balloon (IA-DEB) and standard balloon angioplasty (PTA) in patients with Rutherford Class 4-5-6 CLI. DISCUSSION This multicenter trial has enrolled 358 patients at 13 European centers with independent angiographic core lab adjudication of the primary efficacy endpoint of target lesion late luminal loss (LLL) and clinically driven target lesion revascularization (TLR) in major amputation-free surviving patients through 12-months. An independent wound core lab will evaluate all ischemic wounds to assess the extent of healing and time to healing at 1, 6, and 12 months. A QoL questionnaire including a pain scale will assess changes from baseline scores through 12 months. A Clinical Events Committee and Data Safety Monitoring Board will adjudicate the composite primary safety endpoints of all-cause death, major amputation, and clinically driven TLR at 6 months and other trial endpoints and supervise patient safety throughout the study. All patients will be followed for 5 years. A literature review is presented of the current status of endovascular treatment of CLI with drug-eluting balloon and standard PTA. The rationale and design of the IN.PACT DEEP Trial are discussed. IN.PACT DEEP is a milestone, prospective, randomized, robust, independent core lab-adjudicated CLI trial that will evaluate the role of a new infrapopliteal revascularization technology, the IA-DEB, compared to PTA. It will assess the overall impact on infrapopliteal artery patency, limb salvage, wound healing, pain control, QoL, and patient mobility. The 1-year results of the adjudicated co-primary and secondary endpoints will be available in 2014. TRIAL REGISTRATION NCT00941733

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OBJECTIVES To assess the literature on carotid calcifications defined from panoramic radiographs (PMX) and concurrent diagnosis of stroke and periodontitis. MATERIALS AND METHODS A literature search screening for publications using search terms such as PMX and carotid calcification, stroke and periodontitis was performed in November 2012. RESULTS A total of 189 articles were retrieved, among which 30 were included in the review. The sensitivity for PMX findings of carotid calcifications (CC) compared to a diagnosis by Doppler sonography varied between 31.1-100%. The specificity for PMX findings of carotid calcifications compared to a diagnosis by Doppler sonography varied between 21.4-87.5%. Individuals with CC findings from PMX have more periodontitis and risk for stroke. CONCLUSIONS There is a shortage of well-designed studies in older dentate individuals assessing the associations between periodontitis and radiographic evidence of CC and in relation to stroke or other cardiovascular diseases. STATEMENT OF CLINICAL RELEVANCE: Carotid calcifications are prevalent in patients with periodontitis and such individuals may have an increased risk for stroke. The absence of signs of carotid calcification on panoramic radiographs is indicative of no calcification of carotid arteries.

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Transcatheter aortic valve implantation (TAVI) is a novel therapy, which has transformed the management of inoperable patients presenting with symptomatic severe aortic stenosis (AS). It is also a proven and less invasive alternative therapeutic option for high-risk symptomatic patients presenting with severe AS who are otherwise eligible for surgical aortic valve replacement. Patient age is not strictly a limitation for TAVI but since this procedure is currently restricted to high-risk and inoperable patients, it follows that most patients selected for TAVI are at an advanced age. Patient frailty and co-morbidities need to be assessed and a clinical judgment made on whether the patient will gain a measureable improvement in their quality of life. Risk stratification has assumed a central role in selecting suitable patients and surgical risk algorithms have proven helpful in this regard. However, limitations exist with these risk models, which must be understood in the context of TAVI. When making final treatment decisions, it is essential that a collaborative multidisciplinary "heart team" be involved and this is stressed in the most recent guidelines of the European Society of Cardiology. Choosing the best procedure is contingent upon anatomical feasibility, and multimodality imaging has emerged as an integral component of the pre-interventional screening process in this regard. The transfemoral route is now considered the default approach although vascular complications remain a concern. A minimal vessel diameter of 6 mm is required for currently commercial available vascular introducer sheaths. Several alternative access routes are available to choose from when confronted with difficult iliofemoral anatomy such as severe peripheral vascular disease or diffuse circumferential vessel calcification. The degree of aortic valve leaflet and annular calcification also needs to be assessed as the latter is a risk factor for post-procedural paravalvular aortic regurgitation. The ultimate goal of patient selection is to achieve the highest procedural success rate while minimizing complications and to choose patients most likely to derive tangible benefit from this procedure.

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OBJECTIVES This study reports a series of pitfalls, premature failures and explantations of the third-generation Freedom SOLO (FS) bovine pericardial stentless valve. METHODS A total of 149 patients underwent aortic valve replacement using the FS. Follow-up was 100% complete with an average observation time of 5.5 ± 2.3 years (maximum 8.7 years) and a total of 825 patient-years. Following intraoperative documentation, all explanted valve prostheses underwent histological examination. RESULTS Freedom from structural valve deterioration (SVD) at 5, 6, 7, 8 and 9 years was 92, 88, 80, 70 and 62%, respectively. Fourteen prostheses required explantation due to valve-independent dysfunction (n = 5; i.e. thrombus formation, oversizing, aortic dilatation, endocarditis and suture dehiscence) or valve-dependent failure (acute leaflet tears, n = 4 and severe stenosis, n = 5). Thus, freedom from explantation at 5, 6, 7, 8 and 9 years was 95, 94, 91, 81 and 72%, respectively. An acute vertical tear along the non-coronary/right coronary commissure to the base occurred at a mean of 6.0 years (range 4.3-7.3 years) and affected size 25 and 27 prostheses exclusively. Four FS required explantation after a mean of 7.5 years (range 7.0-8.3 years) due to severe functional stenosis and gross calcification that included the entire aortic root. CONCLUSIONS The FS stentless valve is safe to implant and shows satisfying mid-term results in our single institution experience. Freedom from SVD and explantation decreased markedly after only 6-7 years, so that patients with FS require close observation and follow-up. Exact sizing, symmetric positioning and observing patient limitations are crucial for optimal outcome.

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Postmortem investigation is increasingly supported by Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). This led to the idea to implement a noninvasive or minimally invasive autopsy technique. Therefore, a minimally invasive angiography technique becomes necessary, in order to support the vascular cross section diagnostic. Preliminary experiments investigating different contrast agents for CT and MRI and their postmortem applicability have been performed using an ex-vivo porcine coronary model. MSCT and MRI angiography was performed in the porcine model. Three human corpses were investigated using minimally invasive MSCT angiography. Via the right femoral artery a plastic tube was advanced into the aortic arch. Using a flow adjustable pump the radiopaque contrast agent meglumine-ioxithalamate was injected. Subsequent MSCT scanning provided an excellent anatomic visualization of the human arterial system including intracranial and coronary arteries. Vascular pathologies such as calcification, stenosis and injury were detected. Limitations of the introduced approach are cases of major vessel injury and cases that show an advanced stage of decay.

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The rapid further development of computed tomography (CT) and magnetic resonance imaging (MRI) induced the idea to use these techniques for postmortem documentation of forensic findings. Until now, only a few institutes of forensic medicine have acquired experience in postmortem cross-sectional imaging. Protocols, image interpretation and visualization have to be adapted to the postmortem conditions. Especially, postmortem alterations, such as putrefaction and livores, different temperature of the corpse and the loss of the circulation are a challenge for the imaging process and interpretation. Advantages of postmortem imaging are the higher exposure and resolution available in CT when there is no concern for biologic effects of ionizing radiation, and the lack of cardiac motion artifacts during scanning. CT and MRI may become useful tools for postmortem documentation in forensic medicine. In Bern, 80 human corpses underwent postmortem imaging by CT and MRI prior to traditional autopsy until the month of August 2003. Here, we describe the imaging appearance of postmortem alterations--internal livores, putrefaction, postmortem clotting--and distinguish them from the forensic findings of the heart, such as calcification, endocarditis, myocardial infarction, myocardial scarring, injury and other morphological alterations.