Disappearance of Spontaneous Echographic Contrast after Balloon Mitral Valvuloplasty: An Indicator of Sustained Hemodynamic Improvement

In three patients undergoing mitral balloon valvuloplasty for mitral stenosis transesophageal echocardiography was performed before, immediately after, and 6 months after the procedure. In the one patient with persistent hemodynamically favorable result, the spontaneous echocardiographic contrast, which was seen in all three preoperatively, did not recur; in the other two patients the phenomenon was observed again after 6 months. We conclude that the disappearance of spontaneous echocardiographic contrast might be a functional morphological measure of sustained hemodynamic improvement after balloon mitral valvuloplasty. Copyrigh

Branonium

We study the bound states of brane/antibrane systems by examining the motion of a probe antibrane moving in the background fields of N source branes. The classical system resembles the point-particle central force problem, and the orbits can be solved by quadrature. Generically the antibrane has orbits which are not closed on themselves. An important special case occurs for some Dp-branes moving in three transverse dimensions, in which case the orbits may be obtained in closed form, giving the standard conic sections but with a nonstandard time evolution along the orbit. Somewhat surprisingly, in this case the resulting elliptical orbits are exact solutions, and do not simply apply in the limit of asymptotically-large separation or non-relativistic velocities. The orbits eventually decay through the radiation of massless modes into the bulk and onto the branes, and we estimate this decay time. Applications of these orbits to cosmology are discussed in a companion paper.Comment: 34 pages, LaTeX, 4 figures, uses JHEP

Brane-Antibrane Inflation in Orbifold and Orientifold Models

We analyse the cosmological implications of brane-antibrane systems in string-theoretic orbifold and orientifold models. In a class of realistic models, consistency conditions require branes and antibranes to be stuck at different fixed points, and so their mutual attraction generates a potential for one of the radii of the underlying torus or the 4D string dilaton. Assuming that all other moduli have been fixed by string effects, we find that this potential leads naturally to a period of cosmic inflation with the radion or dilaton field as the inflaton. The slow-roll conditions are satisfied more generically than if the branes were free to move within the space. The appearance of tachyon fields at certain points in moduli space indicates the onset of phase transitions to different non-BPS brane systems, providing ways of ending inflation and reheating the corresponding observable brane universe. In each case we find relations between the inflationary parameters and the string scale to get the correct spectrum of density perturbations. In some examples the small numbers required as inputs are no smaller than 0.01, and are the same small quantities which are required to explain the gauge hierarchy.Comment: 30 pages, 2 figures. Substantial changes on version 1. New cosmological scenarios proposed including the dilaton as the inflaton. Main conclusions unchange

Luminal narrowing after percutaneous transluminal coronary angioplasty. A study of clinical, procedural, and lesional factors related to longterm angiographic outcome

Background. The renarrowing process after successful percutaneous transluminal coronary angioplasty (PTCA) is now believed to be caused by a response-to-injury vessel wall reaction. The magnitude of this process can be assessed by the change in minimal lumen diameter (MLD) at follow-up angiography. The aim of the present study was to find independent patient-related, lesion-related, and procedure-related risk factors for this luminal narrowing process. A model that accurately predicts the amount of luminal narrowing could be an aid in patient or lesion selection for the procedure, and it could improve assessment of medium-term (6 months) prognosis. Modification or control of the identified risk factors could reduce overall restenosis rates, and it could assist in the selection of patients at risk for a large loss in lumen diameter. This population could then constitute the target population for pharmacological intervention studies. Methods and Results. Quantitative angiography was performed on 666 successfully dilated lesions at angioplasty and at 6-month follow-up. Multivaria

Usefulness of quantitative and qualitative angiographic lesion morphology, and clinical characteristics in predicting major adverse cardiac events during and after native coronary balloon angioplasty

Major, adverse cardiac events (death, myocardial infarction, bypass surgery and reintervention) occur in 4 to 7% of all patients undergoing coronary balloon angioplasty. Prospectively collected clinical data, and angiographic quantitative and qualitative lesion morphologic assessment and procedural factors were examined to determine whether the occurrence of these events could be predicted. Of 1,442 patients undergoing balloon angioplasty for native primary coronary disease in 2 European multicenter trials, 69 had major, adverse cardiac procedural or in-hospital complications after ≥1 balloon inflation and were randomly matched with patients who completed an uncomplicated in-hospital course after successful angioplasty. No quantitative angiographic variable was associated with major adverse cardiac events in univariate and multivariate analyses. Univariate analysis showed that major adverse cardiac events were associated with the following preprocedural variables: (1) unstable angina (odds ratio [OR] 3.11; p 45 ° (OR 2.34; p 45 ° (OR 2.87; p 45 ° (OR 2.54; p < 0.006) were independent predictors of major adverse cardiac events

Directional atherectomy for treatment of restenosis within coronary stents: clinical, angiographic and histologic results

Abstract OBJECTIVES: The safety and long-term results of directional coronary atherectomy in stented coronary arteries were determined. In addition, tissue studies were performed to characterize the development of restenosis. METHODS: Directional coronary atherectomy was performed in restenosed stents in nine patients (10 procedures) 82 to 1,179 days after stenting. The tissue was assessed for histologic features of restenosis, smooth muscle cell phenotype, markers of cell proliferation and cell density. A control (no stenting) group consisted of 13 patients treated with directional coronary atherectomy for restenosis 14 to 597 days after coronary angioplasty, directional coronary atherectomy or laser intervention. RESULTS: Directional coronary atherectomy procedures within the stent were technically successful with results similar to those of the initial stenting procedure (2.31 +/- 0.38 vs. 2.44 +/- 0.35 mm). Of five patients with angiographic follow-up, three had restenosis requiring reintervention (surgery in two and repeat atherectomy followed by laser angioplasty in one). Intimal hyperplasia was identified in 80% of specimens after stenting and in 77% after coronary angioplasty or atherectomy. In three patients with stenting, 70% to 76% of the intimal cells showed morphologic features of a contractile phenotype by electron microscopy 47 to 185 days after coronary intervention. Evidence of ongoing proliferation (proliferating cell nuclear antigen antibody studies) was absent in all specimens studied. Although wide individual variability was present in the maximal cell density of the intimal hyperplasia, there was a trend toward a reduction in cell density over time. CONCLUSIONS: Although atherectomy is feasible for the treatment of restenosis in stented coronary arteries and initial results are excellent, recurrence of restenosis is common. Intimal hyperplasia is a nonspecific response to injury regardless of the device used and accounts for about 80% of cases of restenosis. Smooth muscle cell proliferation and phenotypic modulation toward a contractile phenotype are early events and largely completed by the time of clinical presentation of restenosis. Restenotic lesions may be predominantly cellular, matrix or a combination at a particular time after a coronary procedure

Stenting of venous bypass grafts: A new treatment modality for patients who are poor candidates for reintervention

Abstract During a 2-year period, 136 self-expanding Wall-stents were implanted in saphenous vein bypass grafts in 69 patients with end-stage coronary artery disease. All patients had severe symptoms and the majority were poor candidates for either repeat surgery or conventional bypass coronary angioplasty because of unfavorable native anatomy, impaired left ventricular function, or a high-risk bypass lesion anatomy for coronary angioplasty. All procedures were technically successful without major complications and a need for emergency bypass surgery. However, during the hospital stay acute thrombotic complications occurred in seven patients (10%) resulting in one death and acute myocardial infarction in five patients and necessitating emergency repeat PTCA in two patients and repeat CABG in four. Twenty-three patients had serious hemorrhagic complications directly related to the rigorous anticoagulation schedule. Two patients died of fatal cerebral bleeding. During follow-up, another five patients died accounting for a total mortality rate of 12%. At late angiographic follow-up (4.9 ± 3.4 months, n = 53), 25 patients (47%) had a restenosis (≥50% DS) within or immediately adjacent to the stent, necessitating reintervention in 19 patients (PTCA, n = 12; repeat CABG, n = 7). In the group without stent-related restenosis (n = 28), 15 patients had progression of disease in either the native or bypass vessels leading to recurrence of major anginal symptoms within 1 to 24 months. Ten of these patients required further intervention (stent, n = 6; PTCA, n = 3; repeat CABG, n = 1). Stenting in saphenous coronary bypass grafts can be performed safely with excellent immediate angiographic and clinical results. Early occlusion, late restenosis, and bleeding complications associated with the aggressive anticoagulant treatment remain significant limitations. Reintervention as a result of restenosis or progression of disease in other lesions is common. Stenting of diseased bypass grafts in symptomatic patients with end-stage coronary artery disease (who are at high risk for conventional angioplasty or surgical reintervention) may be useful as palliative therapy

Big Corrections from a Little Higgs

We calculate the tree-level expressions for the electroweak precision observables in the SU(5)/SO(5) littlest Higgs model. The source for these corrections are the exchange of heavy gauge bosons, explicit corrections due to non-linear sigma-model dynamics and a triplet Higgs VEV. Weak isospin violating contributions are present because there is no custodial SU(2) global symmetry. The bulk of these weak isospin violating corrections arise from heavy gauge boson exchange while a smaller contribution comes from the triplet Higgs VEV. A global fit is performed to the experimental data and we find that throughout the parameter space the symmetry breaking scale is bounded by f > 4 TeV at 95% C.L. Stronger bounds on f are found for generic choices of the high energy gauge couplings. We find that even in the best case scenario one would need fine tuning of less than a percent to get a Higgs mass as light as 200 GeV.Comment: 20 pages, 5 figures included, typos fixed, comments on the effects of extra vector-like heavy fermions adde

Urban proximity while breeding is not a predictor of perfluoroalkyl substance contamination in the eggs of brown pelicans

Identifying sources of exposure to chemical stressors is difficult when both target organisms and stressors are highly mobile. While previous studies have demonstrated that populations of some organisms proximal to urban centers may display increased burdens of human-created chemicals compared to more distal populations, this relationship may not be universal when applied to organisms and stressors capable of transboundary movements. We examined eggs of brown pelicans (Pelecanus occidentalis), a nearshore seabird with daily movements ranging from local to 50 km and annual migrations ranging from year-round residency to 1500 km. Thirty-six eggs from three breeding colonies located at increasing distances to a major urban center (Charleston, South Carolina, USA) were analyzed for concentrations of per- and polyfluoroalkyl substances (PFAS). Areas of high use for each colony during the breeding season were also assessed via the tracking of adult pelicans from each colony using GPS-PTT satellite transmitters and overlapped with measures of relative urbanization via land cover data. We report potentially significant ∑PFAS concentrations in the eggs of pelicans (175.4 ± 120.1 ng/g w wt. SD), driven largely by linear perfluorooctane sulfonate (n-PFOS) (48–546 ng/g w wt.). Residues of the precursor compound perfluorooctane sulfonamide (FOSA) were also present in pelican eggs, suggesting continued exposure of local wildlife beyond implemented phaseouts of some PFAS. For most analytes, egg concentrations did not exhibit a significant spatial structure despite some differentiation in high-use areas unlike similar data for another regional apex predator, the bottlenose dolphin (Tursiops truncatus). We suggest that the partially migratory nature of brown pelicans during the non-breeding season, combined with daily ranges that may extend to 50 km from local point sources, may have homogenized exposure across individuals. Charleston likely remains a major source for PFAS in the overall region, however, given the high concentrations observed as well as known releases of PFAS in the nearshore environment

Predicting hedgehog mortality risks on British roads using habitat suitability modelling

Road vehicle collisions are likely to be an important contributory factor in the decline of the European hedgehog (Erinaceus europaeus) in Britain. Here, a collaborative roadkill dataset collected from multiple projects across Britain was used to assess when, where and why hedgehog roadkill are more likely to occur. Seasonal trends were assessed using a Generalized Additive Model. There were few casualties in winter—the hibernation season for hedgehogs—with a gradual increase from February that reached a peak in July before declining thereafter. A sequential multi-level Habitat Suitability Modelling (HSM) framework was then used to identify areas showing a high probability of hedgehog roadkill occurrence throughout the entire British road network (∼400,000 km) based on multi-scale environmental determinants. The HSM predicted that grassland and urban habitat coverage were important in predicting the probability of roadkill at a national scale. Probabilities peaked at approximately 50% urban cover at a one km scale and increased linearly with grassland cover (improved and rough grassland). Areas predicted to experience high probabilities of hedgehog roadkill occurrence were therefore in urban and suburban environments, that is, where a mix of urban and grassland habitats occur. These areas covered 9% of the total British road network. In combination with information on the frequency with which particular locations have hedgehog road casualties, the framework can help to identify priority areas for mitigation measures