984 resultados para Patent extensions


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Proof that percutaneous closure of the patent foramen ovale (PFO) is superior to medical treatment is still incomplete. Paradoxical embolism is a rare event occurring over decades rather than years. None of the 4 randomized trials published carried enough patients or was followed up for long enough to reach superiority endpoints. All data, however, point to a benefit of PFO closure. Free wall erosion (exceedingly rare) and triggering of atrial fibrillation (in about 1% of patients) are the only noteworthy complications. They are outweighed by the supposedly prevented events of paradoxical embolisms, such as stroke, transient ischemic attacks, myocardial infarctions, or other systemic embolisms. Medical treatment with perhaps the exception of lifelong oral anticoagulation provides less protection. During a 10-year follow-up of a comparative study the annual mortality was significantly lower in the patients with PFO closure (0.4%) than in those with medical treatment (1.1%, P < 0.03). PFO closure can be accomplished in less than 1 hour with immediate resumption of physical activity. It represents thus a kind of mechanical vaccination.

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Stroke is the most debilitating cardiovascular event. It has a variety of causes that may be present simultaneously. In young or otherwise healthy people a patent foramen ovale (PFO) is increasingly searched for. In stroke of the elderly atherosclerosis and atrial fibrillation are in the foreground but the PFO should not be ignored. The risk of a PFO related stroke over time is controversial and so is its prevention by PFO closure. Percutaneous PFO closure is a minimally invasive procedure which can be performed with high success and low morbidity. We review the rationale for PFO closure for secondary prevention of embolic events.

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With three recently published randomized trials on patent foramen ovale (PFO) closure, the concept of PFO closure to reduce recurrent strokes has been proven; however, PFO closure is currently only considered for secondary prevention. Given the potential devastating consequences of a PFO-related event, we advocate screening for and closure of a PFO for primary prevention in high-risk populations. Such populations include patients who are suffering from a disease that is associated with PFO (e.g., migraine) or patients with high-risk hobbies/professions (e.g., weight-lifters, frequent-flyers, and deep sea divers). Looking at young people with a remaining average life expectancy of 50 years, we have to close 2.4 PFOs to prevent one stroke. This should support a more proactive attitude toward PFO screening and closure.

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We regularize compact and non-compact Abelian Chern–Simons–Maxwell theories on a spatial lattice using the Hamiltonian formulation. We consider a doubled theory with gauge fields living on a lattice and its dual lattice. The Hilbert space of the theory is a product of local Hilbert spaces, each associated with a link and the corresponding dual link. The two electric field operators associated with the link-pair do not commute. In the non-compact case with gauge group R, each local Hilbert space is analogous to the one of a charged “particle” moving in the link-pair group space R2 in a constant “magnetic” background field. In the compact case, the link-pair group space is a torus U(1)2 threaded by k units of quantized “magnetic” flux, with k being the level of the Chern–Simons theory. The holonomies of the torus U(1)2 give rise to two self-adjoint extension parameters, which form two non-dynamical background lattice gauge fields that explicitly break the manifest gauge symmetry from U(1) to Z(k). The local Hilbert space of a link-pair then decomposes into representations of a magnetic translation group. In the pure Chern–Simons limit of a large “photon” mass, this results in a Z(k)-symmetric variant of Kitaev’s toric code, self-adjointly extended by the two non-dynamical background lattice gauge fields. Electric charges on the original lattice and on the dual lattice obey mutually anyonic statistics with the statistics angle . Non-Abelian U(k) Berry gauge fields that arise from the self-adjoint extension parameters may be interesting in the context of quantum information processing.

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BACKGROUND There is no agreement of the influence of patent ductus arteriosus (PDA) on outcomes in patients with necrotizing enterocolitis (NEC). In this study, we assessed the influence of PDA on NEC outcomes. METHODS A retrospective study of 131 infants with established NEC was performed. Outcomes (death, disease severity, need for surgery, hospitalization duration), as well as multiple clinical parameters were compared between NEC patients with no congenital heart disease (n=102) and those with isolated PDA (n=29). Univariate, multivariate and stepwise logistic regression analyses were performed. RESULTS Birth weight and gestational age were significantly lower in patients with PDA [median (95% CI): 1120 g (1009-1562 g), 28.4 wk (27.8-30.5 wk)] than in those without PDA [median (95% CI): 1580 g (1593-1905 g), 32.4 wk (31.8-33.5 wk); P<0.05]. The risk of NEC-attributable fatality was higher in NEC patients with PDA (35%) than in NEC patients without PDA (14%)[univariate odds ratio (OR)=3.3, 95% CI: 1.8-8.6, P<0.05; multivariate OR=2.4, 95% CI: 0.82-2.39, P=0.111]. Significant independent predictors for nonsurvival within the entire cohort were advanced disease severity stage III (OR=27.9, 95% CI: 7.4-105, P<0.001) and birth weight below 1100 g (OR=5.7, 95% CI: 1.7-19.4, P<0.01). CONCLUSIONS In patients with NEC, the presence of PDA is associated with an increased risk of death. However, when important differences between the two study groups are controlled, only birth weight and disease severity may independently predict mortality.

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OBJECTIVE The aim of this report is to describe symptoms that can suggest the presence of a patent nasopalatine duct and to illustrate three cases. SUMMARY Patent nasopalatine ducts connecting the oral cavity with the nasal cavity are extremely rare. This malformation can be considered a developmental abnormality. Clinically, patent nasopalatine ducts appear as single or double spherical or oval apertures lateral or posterior to the incisive papilla. This type of anatomical malformation can be associated with an unclear pain sensation in the anterior maxillary region, which may be misinterpreted for example as toothache of endodontic origin. However, persisting nasopalatine ducts can also exist as an asymptomatic abnormality with no clinical sign of discomfort. Accordingly, understanding the differential diagnosis of a possible patent nasopalatine duct can prevent a general practitioner from performing unnecessary interventions, such as endodontic treatments, apical surgeries, or tooth extractions.

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Welsch (Projektbearbeiter): Darstellung der Geschehnisse des 18. März 1848 (Aufstand in Berlin und Barrikadenkämpfe gegen das Militär) aus der Sicht Friedrich Wilhelms IV. Aufruf zur Niederlegung der Barrikaden, Versprechen des Truppenrückzuges von den öffentlichen Straßen und Plätzen

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AIMS The preferred antithrombotic strategy for secondary prevention in patients with cryptogenic stroke (CS) and patent foramen ovale (PFO) is unknown. We pooled multiple observational studies and used propensity score-based methods to estimate the comparative effectiveness of oral anticoagulation (OAC) compared with antiplatelet therapy (APT). METHODS AND RESULTS Individual participant data from 12 databases of medically treated patients with CS and PFO were analysed with Cox regression models, to estimate database-specific hazard ratios (HRs) comparing OAC with APT, for both the primary composite outcome [recurrent stroke, transient ischaemic attack (TIA), or death] and stroke alone. Propensity scores were applied via inverse probability of treatment weighting to control for confounding. We synthesized database-specific HRs using random-effects meta-analysis models. This analysis included 2385 (OAC = 804 and APT = 1581) patients with 227 composite endpoints (stroke/TIA/death). The difference between OAC and APT was not statistically significant for the primary composite outcome [adjusted HR = 0.76, 95% confidence interval (CI) 0.52-1.12] or for the secondary outcome of stroke alone (adjusted HR = 0.75, 95% CI 0.44-1.27). Results were consistent in analyses applying alternative weighting schemes, with the exception that OAC had a statistically significant beneficial effect on the composite outcome in analyses standardized to the patient population who actually received APT (adjusted HR = 0.64, 95% CI 0.42-0.99). Subgroup analyses did not detect statistically significant heterogeneity of treatment effects across clinically important patient groups. CONCLUSION We did not find a statistically significant difference comparing OAC with APT; our results justify randomized trials comparing different antithrombotic approaches in these patients.

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BACKGROUND There is considerable interindividual variability in pulmonary artery pressure among high-altitude (HA) dwellers, but the underlying mechanism is not known. At low altitude, a patent foramen ovale (PFO) is present in about 25% of the general population. Its prevalence is increased in clinical conditions associated with pulmonary hypertension and arterial hypoxemia, and it is thought to aggravate these problems. METHODS We searched for a PFO (transesophageal echocardiography) in healthy HA dwellers (n = 22) and patients with chronic mountain sickness (n = 35) at 3,600 m above sea level and studied its effects (transthoracic echocardiography) on right ventricular (RV) function, pulmonary artery pressure, and vascular resistance at rest and during mild exercise (50 W), an intervention designed to further increase pulmonary artery pressure. RESULTS The prevalence of PFO (32%) was similar to that reported in low-altitude populations and was not different in participants with and without chronic mountain sickness. Its presence was associated with RV enlargement at rest and an exaggerated increase in right-ventricular-to-right-atrial pressure gradient (25 ± 7 mm Hg vs 15 ± 9 mm Hg, P < .001) and a blunted increase in fractional area change of the right ventricle (3% [-1%, 5%] vs 7% [3%, 16%], P = .008) during mild exercise. CONCLUSIONS These findings show, we believe for the first time, that although the prevalence of PFO is not increased in HA dwellers, its presence appears to facilitate pulmonary vasoconstriction and RV dysfunction during a mild physical effort frequently associated with daily activity. TRIAL REGISTRY ClinicalTrials.gov; No.: NCT01182792; URL: www.clinicaltrials.gov.