MR and CT imaging of pulmonary valved conduits in children and adolescents: normal appearance and complications.

BACKGROUND: The Contegra® is a conduit made from the bovine jugular vein and then interposed between the right ventricle and the pulmonary artery. It is used for cardiac malformations in the reconstruction of right ventricular outflow tract. OBJECTIVE: To describe both normal and pathological appearances of the Contegra® in radiological imaging, to describe imaging of complications and to define the role of CT and MRI in postoperative follow-up. MATERIALS AND METHODS: Forty-three examinations of 24 patients (17 boys and 7 girls; mean age: 10.8 years old) with Contegra® conduits were reviewed. Anatomical description and measurements of the conduits were performed. Pathological items examined included stenosis, dilatation, plicature or twist, thrombus or vegetations, calcifications and valvular regurgitation. Findings were correlated to the echographic gradient through the conduit when available. RESULTS: CT and MR work-up showed Contegra® stenosis (n = 12), dilatation (n = 9) and plicature or twist (n = 7). CT displayed thrombus or vegetations in the Contegra® in three clinically infected patients. Calcifications of the conduit were present at CT in 12 patients and valvular regurgitation in three patients. The comparison between CT and/or MR results showed a good correlation between the echographic gradient and the presence of stenosis in the Contegra®. CONCLUSION: CT and MR bring additional information about permeability and postoperative anatomy especially when echocardiography is inconclusive. Both techniques depict the normal appearance of the conduit, and allow comparison and precise evaluation of changes in the postoperative follow-up

Morphological and physiological species-dependent characteristics of the rodent Grueneberg ganglion.

In the mouse, the Grueneberg ganglion (GG) is an olfactory subsystem implicated both in chemo- and thermo-sensing. It is specifically involved in the recognition of volatile danger cues such as alarm pheromones and structurally-related predator scents. No evidence for these GG sensory functions has been reported yet in other rodent species. In this study, we used a combination of histological and physiological techniques to verify the presence of a GG and investigate its function in the rat, hamster, and gerbil comparing with the mouse. By scanning electron microscopy (SEM) and transmitted electron microscopy (TEM), we found isolated or groups of large GG cells of different shapes that in spite of their gross anatomical similarities, display important structural differences between species. We performed a comparative and morphological study focusing on the conserved olfactory features of these cells. We found fine ciliary processes, mostly wrapped in ensheating glial cells, in variable number of clusters deeply invaginated in the neuronal soma. Interestingly, the glial wrapping, the amount of microtubules and their distribution in the ciliary processes were different between rodents. Using immunohistochemistry, we were able to detect the expression of known GG proteins, such as the membrane guanylyl cyclase G and the cyclic nucleotide-gated channel A3. Both the expression and the subcellular localization of these signaling proteins were found to be species-dependent. Calcium imaging experiments on acute tissue slice preparations from rodent GG demonstrated that the chemo- and thermo-evoked neuronal responses were different between species. Thus, GG neurons from mice and rats displayed both chemo- and thermo-sensing, while hamsters and gerbils showed profound differences in their sensitivities. We suggest that the integrative comparison between the structural morphologies, the sensory properties, and the ethological contexts supports species-dependent GG features prompted by the environmental pressure

Persistent left superior vena cava in cardiac congenital surgery.

Persistent left superior vena cava (LSVC) is a relatively frequent finding in congenital cardiac malformation. The scope of the study was to analyze the timing of diagnosis of persistent LSVC, the timing of diagnosis of associated anomalies of the coronary sinus, and the global impact on morbidity and mortality of persistent LSVC in children with congenital heart disease after cardiac surgery. Retrospective analysis of a cohort of children after cardiac surgery on bypass for congenital heart disease. Three hundred seventy-one patients were included in the study, and their median age was 2.75 years (IQR 0.65-6.63). Forty-seven children had persistent LSVC (12.7 %), and persistent LSVC was identified on echocardiography before surgery in 39 patients (83 %). In three patients (6.4 %) with persistent LSVC, significant inflow obstruction of the left ventricle developed after surgery leading to low output syndrome or secondary pulmonary hypertension. In eight patients (17 %), persistent LSVC was associated with a partially or completely unroofed coronary sinus and in two cases (4 %) with coronary sinus ostial atresia. Duration of mechanical ventilation was significantly shorter in the control group (1.2 vs. 3.0 days, p = 0.04), whereas length of stay in intensive care did not differ. Mortality was also significantly lower in the control group (2.5 vs. 10.6 %, p = 0.004). The results of study show that persistent LSVC in association with congenital cardiac malformation increases the risk of mortality in children with cardiac surgery on cardiopulmonary bypass. Recognition of a persistent LSVC and its associated anomalies is mandatory to avoid complications during or after cardiac surgery

Realizations of the Lie superalgebra q(2) and applications

The Lie superalgebra q(2) and its class of irreducible representations V_p of dimension 2p (p being a positive integer) are considered. The action of the q(2) generators on a basis of V_p is given explicitly, and from here two realizations of q(2) are determined. The q(2) generators are realized as differential operators in one variable x, and the basis vectors of V_p as 2-arrays of polynomials in x. Following such realizations, it is observed that the Hamiltonian of certain physical models can be written in terms of the q(2) generators. In particular, the models given here as an example are the sphaleron model, the Moszkowski model and the Jaynes-Cummings model. For each of these, it is shown how the q(2) realization of the Hamiltonian is helpful in determining the spectrum.Comment: LaTeX file, 15 pages. (further references added, minor changes in section 5

Long-term outcome of congenital aortic valve stenosis: predictors of reintervention.

OBJECTIVES: To evaluate long-term outcome of initial aortic valve intervention in a paediatric population with congenital aortic stenosis, and to determine risk factors associated with reintervention. PATIENTS AND METHODS: From 1985 to 2009, 77 patients with congenital aortic stenosis and a mean age of 5.8±5.6 years at diagnosis were followed up in our institution for 14.8±9.1 years. RESULTS: First intervention was successful with 86% of patients having a residual peak aortic gradient 1 regurgitation increased by 7%. Long-term survival after the first procedure was excellent, with 91% survival at 25 years. At a mean interval of 7.6±5.3 years, 30 patients required a reintervention (39%), mainly because of a recurrent aortic stenosis. Freedom from reintervention was 97, 89, 75, 53, and 42% at 1, 10, 15, 20, and 25 years, respectively. Predictors of reintervention were residual peak aortic gradient (p=0.0001), aortic regurgitation post-intervention >1 (p=0.02), prior balloon aortic valvuloplasty (p=0.04), and increased left ventricular posterior wall thickness (p=0.1). CONCLUSIONS: Aortic valve intervention is a safe and effective procedure for congenital aortic stenosis with excellent survival results. However, rate of reintervention is high and influenced by increased left ventricular posterior wall thickness pre-intervention, prior balloon valvuloplasty, higher residual peak systolic valve gradient, and more than mild regurgitation post-intervention. The study highlights that long-term follow-up is recommended for these patients

The Morphology of N=6 Chern-Simons Theory

We tabulate various properties of the language of N=6 Chern-Simons Theory, in the sense of Polyakov. Specifically we enumerate and compute character formulas for all syllables of up to four letters, i.e. all irreducible representations of OSp(6|4) built from up to four fundamental fields of the ABJM theory. We also present all tensor product decompositions for up to four singletons and list the (cyclically invariant) four-letter words, which correspond to single-trace operators of length four. As an application of these results we use the two-loop dilatation operator to compute the leading correction to the Hagedorn temperature of the weakly-coupled planar ABJM theory on R \times S^2.Comment: 41 pages, 1 figure; v2: minor correction

Improvement in perioperative care in pediatric cardiac surgery by shifting the primary focus of treatment from cardiac output to perfusion pressure: Are beta stimulants still needed?

An important aspect of perioperative care in pediatric cardiac surgery is maintenance of optimal hemodynamic status using vasoactive/inotropic agents. Conventionally, this has focused on maintenance of cardiac output rather than perfusion pressure. However, this approach has been abandoned in our center in favor of one focusing primarily on perfusion pressure, which is presented here and compared to the conventional approach. A retrospective study. Regional center for congenital heart disease. University Hospital of Lausanne, Switzerland. All patients with Aristotle risk score ≥8 that underwent surgery from 1996 to 2012 were included. Patients operated between 1996 and 2005 (Group 1: 206 patients) were treated according to the conventional approach. Patients operated between 2006 and 2012 (Group 2: 217 patients) were treated according to our new approach. All patients had undergone surgery for correction or palliation of congenital cardiac defects. Mortality, duration of ventilation and inotropic treatment, use of ECMO, and complications of poor peripheral perfusion (need for hemofiltration, laparotomy for enterocolitis, amputation). The two groups were similar in age and complexity. Mortality was lower in group 2 (7.3% in group 1 vs 1.4% in group 2, P < .005). Ventilation times (hours) and number of days on inotropic/vasoactive treatment (all agents), expressed as median and interquartile range [Q1-Q3] were shorter in group 2: 69 [24-163] hours in group 1 vs 35 [22-120] hours in group 2 (P < .01) for ventilation, and 9 [3-5] days in group 1 vs 7 [2-5] days in group 2 (P < .05) for inotropic/vasoactive agents. There were no differences in ECMO usage or complications of peripheral perfusion. Results in pediatric cardiac surgery may be improved by shifting the primary focus of perioperative care from cardiac output to perfusion pressure

Geosciences Roadmap for Research Infrastructures 2025–2028 by the Swiss Geosciences Community

This community roadmap presents an integrative approach including the most urgent infrastructure requests for the future development of geosciences in Switzerland. It recommends to strengthen the multidisciplinary nature of the geosciences by putting all activities under the roof of the Integrated Swiss Geosciences supported by four specific research infrastructure pillars. The roadmap represents the view of the Swiss scientific community in the field of geosciences and is a formal element of the process to elaborate the Swiss Roadmap for Research Infrastructures 2023. This bottom-up contribution to the identification and selection of important national and international research infrastructures has been coordinated by the Swiss Academy of Sciences (SCNAT) on a mandate by the State Secretariat for Education, Research and Innovation (SERI).ISSN:2297-1564ISSN:2297-157