Initial Use of Endothelial Progenitor Cells Capturing Stents in Paediatric Congenital Heart Disease

INTRODUCTION: Stenosis, mediated by neointimal hyperplasia and thrombosis, is a major limiting factor in successful stent implantation. The introduction of a stent, coated in its endoluminal surface by antihuman CD34 antibodies with endothelial progenitor cell-capturing properties, opens the possibility of promoting a rapid and normal functioning coverage by endothelium and thus avoids both an excessive cell proliferation within stent and the need for long-term dual antiplatelet therapy. These stents, developed for adult coronary artery disease, have not yet been implanted in children or in those with congenital heart disease. OBJECTIVE AND METHODS: In this paper, we describe the implantation of Genous® stents in three children with cyanotic congenital heart disease and obstructed systemic-to-pulmonary shunts. We describe the use of this stent and address its potential feasibility in paediatric congenital heart disease. RESULTS: To maintain the patency of two modified Blalock-Taussig shunts and one ductus arteriosus, four Genous® stents were implanted in three infants with cyanotic heart disease. All procedures were immediately successful, with resolution of stenosis and improvement in transcutaneous oxygen saturation from 66% ± 3.6% to 92% ± 2.6%. In the follow-up, one stent had no occlusion; however, the remaining two had partial occlusion after 5 and 5.5 months, which were successfully managed with balloon dilatation preceding elective definitive surgical correction. CONCLUSION: In our preliminary experience, we demonstrated that Genous® stent implantation was feasible in infants with complex congenital heart disease. Additional studies with larger samples and longer follow-up are required to confirm the potential benefits of this technology in this clinical setting.info:eu-repo/semantics/publishedVersio

A Papillary Fibroelastoma of the Tricuspid Valve

Primary cardiac tumours are rare in children. Of these, papillary fibroelastomas are unusual but benign, usually being found in adults. There are only sporadic cases reported in children. We diagnosed such a papillary fibroelastoma involving the tricuspid valve in an asymptomatic child during a routine cardiac investigation

Ecocardiografia de Speckle Tracking do Ventrículo Direito: uma Nova Ferramenta para a Tomada de Decisão após a Reparação Cirúrgica da Tetralogia de Fallot?

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Uncommon Multicystic Lesion of the Interventricular Septum in a 7-Year-Old Boy: Unusual Presentation of an Intracardiac Teratoma

Intracardiac teratomas are very rare primary cardiac tumors; only a few cases have been reported. We present the case of a 7-year-old boy who early in life showed pulmonary stenosis and needed percutaneous and surgical procedures, including sectioning of the right ventricular bands and reconstruction of the right ventricular outflow tract. At the age of 7 years the patient received a diagnosis of a multilobular cystic mass in the right ventricle adherent to the interventricular septum, which was not present at birth. Successful surgical resection was performed. Histologic examination revealed a mature teratoma. We emphasize the differential diagnosis of teratomas in cystic lesions of the interventricular septum

Exercise-Induced Intraventricular Obstruction in a Child with Near Syncope and Chest Pain During Exercise

We report the case of a 10-year-old girl with two episodes of light-headedness and chest pain during exercise. She had an unremarkable clinical record, physical examination, ECG, and echocardiogram. Noninvasive ischemia tests were positive, but coronary angiography was normal. Exercise stress echocardiogram revealed an exercise-induced intra-left-ventricular obstruction with a peak gradient of 78 mmHg and replicated her symptoms. After starting beta-blocker therapy her clinical status improved and no residual obstruction was detected. The authors review this unsuspected clinical condition, seldom reported in the adult population and, to our knowledge, never before in a child

Percutaneous Treatment of Pulmonary Atresia with Intact Ventricular Septum: Pulmonary Valve Perforation Using Radiofrequency Energy and Arterial Duct Stenting

A atrésia pulmonar com septo interventricular intacto (AtrP-SI) é uma cardiopatia congénita rara e de prognóstico reservado. Apresenta grande variabilidade anatómica, com diversos graus de hipoplasia do ventrículo direito (VD) o que condiciona a abordagem terapêutica. Idealmente, o objectivo é a reconstituição de uma circulação de tipo biventricular. Para o efeito, dispomos de técnicas cirúrgicas e percutâneas. A perfuração da válvula pulmonar com energia de radiofrequência (RF) é um método válido para doentes com atresia de tipo membranoso, VD sem hipoplasia marcada (bipartido ou tripartido) e circulação coronária não dependente do VD. Por vezes, há necessidade de suplementar a circulação pulmonar implantando um stent no canal arterial. Desta forma é possível tratar alguns doentes com técnicas exclusivamente percutâneas. Relatamos o primeiro caso conhecido em Portugal de um recém-nascido com AtrP-SI submetido a perfuração com radiofrequência e, num segundo tempo, implantação de stent no canal arterial

ARCHAEOLOGICAL GEOPHYSICS IN PORTUGAL – SOME SURVEY EXAMPLES

The first attempts to apply geophysical methods to archaeological sites in Portugal date from the mid-sixties of the last century. Since then, geophysical methods have been used more and more frequently to help on archaeological site recognition, delineating buried structures, and help on excavating strategies. The first geophysical methods used in Portugal were geoelectrical methods followed by magnetic methods; today those two methods are still used; however, georadar and electrical resistivity tomography have also been used on a routine basis whenever the local conditions allow their use. Four archaeological sites will be described as examples on the use of geophysical methods in Archaeology. Two of them are from roman times (the Roman Villa of Tourega, in central Portugal and the Roman town of Troia, in the west coast of Portugal), one is from Neolithic times (a burial mound in central Portugal); the last one is a recent archaeological site (eighteenth century) and has to do with the location of a crypt known to exist in the garden of the Portuguese Legislature in Lisbon. Only electrical resistivity tomography and georadar were used. The sites were chosen because in all of them there were already previously excavated areas or there were plans for future excavation. When choosing those sites the idea was to be able to compare the interpretations of the geophysical data with the results of the excavations

A Rare but Real Necessity: Case Report of Coronary Artery Stenting in an Infant

Percutaneous coronary intervention (PCI) is an extremely common and well-established procedure in adults which is rarely performed in children. We present a case of a successful left main coronary artery stenting in a small infant with a congenital coronary artery anomaly. We highlight the technical challenges of performing a PCI in a small patient, the risks of antithrombotic prophylaxis in this age group, and the importance of the combined work of the adult and pediatric interventional cardiologist.info:eu-repo/semantics/publishedVersio

Dynamical mean field modelling and estimation of neuronal oscillations

Oscillations in neural activity are a ubiquitous phenomenon in the brain. They span multiple timescales and correlate with a myriad of physiological and pathological conditions. Given their intrinsic dynamical nature, mathematical and computational modelling tools have proven to be indispensible in order to interpret and formalize the mechanisms through which these oscillations arise. In this Thesis, I developed a new methodological framework that allows the assimilation of experimental data into biophysically plausible models of neural oscillations. Motivated by the fast oscillatory activity (30 ~ 130 Hz) at the onset of focal epileptic seizures, I started by investigating, via means of bifurcation analyses, whether such fast oscillations can be plausibly described by conductance-based neural mass models. Neural mass models have enjoyed success in describing several forms of epileptiform activity (e.g. spike-and-wave seizures and interictal spikes), but I found that, in order to generate such fast oscillations, the parameters of this family of models would have to depart significantly from biophysical plausibility. These results motivated the exploration of full mean-field models of spiking neurons to characterise this type of dynamics. I hence proposed a variant of a mean-field neural population model based on the Fokker-Planck equation of conductance-based, stochastic, leaky integrate-and-fire neurons. This modelling approach was chosen for its capacity to describe arbitrary network configurations and predict firing rates, trans-membrane currents and local field potentials. I introduced a new numerical scheme that makes the computational cost of integrating the ensuing partial differential equations scale linearly with the number of nodes of the networks. These advances are crucial for the practical implementation of model inversion schemes. I then built upon the literature of Dynamic Causal Modelling to develop a Bayesian model inversion algorithm applicable to dynamical systems in limit cycle regimes. I applied the scheme to the mean-field models described above, using experimental data recordings of carbachol-induced gamma oscillations, in the CA1 region of mice hippocampal slice preparations. The estimated model was able to make accurate predictions about independent data features; namely inter-spike-interval distributions. Also, the inverted models were qualitatively compatible with the observation that excitatory pyramidal cells and inhibitory interneurons play equally important roles in the dynamics of these oscillations (as opposed to interneuron-dominated gamma oscillations). I also explored the applicability of this inversion scheme to neural mass models of electroencephalographically recorded spike-and-wave seizures in humans. In conclusion, the work presented in this thesis provides significant new contributions to model based analyses of neuronal oscillatory data, and helps to bridge single-neuron measurements to network-level interactions