Quasi-degeneracies in a 2-spin system : symmetry aspects and a perturbational approach to tunnel splitting

«Erworben im Rahmen der Schweizer Nationallizenzen (http://www.nationallizenzen.ch)»A large number of energy levels in different invariant subspaces of the anisotropic XY-model are quasi-degenerate in a wide parameter range, i.e., their spacing is much smaller than the mean level spacing of the system. These quasi-degeneracies can be interpreted in two ways: (i) as tunnel splitting, (ii) as weak level splitting related to a parametric point of exact degeneracy. Starting from the second interpretation we calculate the tunnel splitting by use of perturbative methods

Somatic development long after the Fontan operation: Factors influencing catch-up growth

ObjectiveAs mortality and morbidity after the Fontan operation has improved, long-term outcome, including developmental aspects, have become more important. To understand the long-term effects of this operation, we followed somatic development for up to 15 years.MethodsWe evaluated 90 patients who underwent the Fontan operation between 1984 and 2004 (mean follow-up, 11.8 ± 4.2 years). The modified Fontan operations were atriopulmonary anastomosis (n = 19) and total cavopulmonary connection (n = 71). Mean age at the time of surgical intervention was 5.5 ± 4.8 years. Weight, height, and body mass index were evaluated preoperatively and postoperatively and given as percentiles on a normal growth curve.ResultsPostoperative weight, height, and body mass index reached the 47.2 ± 35.6, 37.9 ± 30.4, and 41.6 ± 31.2 percentiles, which were significantly better than preoperative values (the 21.6 ± 25.9, 25.9 ± 25.7, and 20.0 ± 25.1 percentiles). Although neither early surgical intervention nor anatomic features affected postoperative growth, early Fontan completion demonstrated better somatic development in subgroups of tricuspid atresia. Prior bidirectional Glenn shunting provided better weight gain before the Fontan operation. Prior atrioseptectomy, central shunt, and pulmonary artery reconstruction were associated with impaired somatic development. Reoperation and catheter-based intervention improved somatic development.ConclusionsLong-term catch-up growth can be observed in patients after the Fontan operation. Early volume-unloading procedures might lead to better somatic growth. Prior atrioseptectomy, central shunt, and pulmonary artery reconstruction are associated with impaired weight and height gain, implying that the severity of the underlying diseases affects postoperative somatic development

Removal of temporary pacemaker after cardiac surgery in infants: A harmless procedure?

External pacemakers (PM) via temporary epicardial leads are routinely applied to infants and children during heart surgery, which usually, after an uneventful post surgical course, can be removed without complications. We report about two infants with complex congenital heart defects after cardiac surgery (arterial switch and Mustard operation for Transposition of the great arteries). Intraoperative these patients received temporary epicardial PM wires. Thirteen and 18 days post surgery, respectively, the PM wires were removed under electrocardiogram (ECG) monitoring. The patients showed acute ECG changes in terms of significant ST elevation during and after removing their pacing wires. Clinically, patients were stable and subsequent echocardiographic examination showed no evidence of myocardial dysfunction or pericardial effusion. In the course of time, patients showed no signs of arrhythmia or abnormal ECG changes. The decision to place temporary pacing wires during the cardiac surgery in patients with congenital heart defects should be considered carefully and their removal should occur under ECG monitoring as soon as the situation of the patient allows. It should be taken into consideration that a complication like this case may be related to delayed removal of temporary PM’s leads. © 2012 - IOS Press and the authors

Intrapericardial migration of dislodged sternal struts as late complication of open pectus excavatum repairs

<p>Abstract</p> <p>We present a case of sternal steel strut dislodgement and migration in a patient undergoing Ravitch repair for pectus excavatum (PE) 37 years ago. Broken struts perforated the right ventricle and right ventricular outflow tract (RVOT) and additionally migrated into the left upper lobar bronchus.</p> <p>Dislodged sternal struts represent rare complications after surgical repair of patients suffering from pectus excavatum. Reviewing the literature, only five cases of intrapericardial migration of dislodged sternal struts or wires have been reported so far.</p> <p>In our case, the first strut was removed from the airways through a left antero-lateral thoracotomy. Using cardiopulmonary bypass, a second strut was removed via ventriculotomy. These life-threatening sequelae underscore the importance of postoperative follow-up and early removal of osteosynthetic materials used in open PE repair. Accurate preoperative localization of migrated materials and availability of CPB support are crucial for successful surgical removal.</p> <p>Introduction</p> <p>The migration of dislodged sternal steel struts or wires into the pericardium and cardiac cavities is a rare but life-threatening complication of open pectus excavatum (PE) repair <abbrgrp><abbr bid="B1">1</abbr></abbrgrp>. Removal of these materials poses a challenge for cardiothoracic surgeons. Herein, the authors report a case of migration of dislodged steel struts through the right ventricle and right ventricular outflow tract (RVOT) into the left upper lobar bronchus in a patient who underwent Ravitch repair 37 years ago.</p

Iron Status and Analysis of Efficacy and Safety of Ferric Carboxymaltose Treatment in Patients with Inflammatory Bowel Disease

Background and Aims:We analyzed iron deficiency and the therapeutic response following intravenous ferric carboxymaltose in a large single-center inflammatory bowel disease (IBD) cohort. Methods: 250 IBD patients were retrospectively analyzed for iron deficiency and iron deficiency anemia. A subgroup was analyzed regarding efficacy and side effects of iron supplementation with ferric carboxymaltose. Results: In the cohort (n = 250), 54.4% of the patients had serum iron levels 60 mu g/dl, 61.6% had ferritin >100 ng/ml, and 90.7% reached Hb >12/13 g/dl at follow-up (p < 0.0001 for all parameters vs. pretreatment values). The most frequent adverse event was a transient increase of liver enzymes with male gender as risk factor (p = 0.008, OR 8.62, 95% CI 1.74-41.66). Conclusions: Iron deficiency and anemia are frequent in IBD patients. Treatment with ferric carboxymaltose is efficious, safe and well tolerated in iron-deficient IBD patients. Copyright (C) 2011 S. Karger AG, Base

Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference