Opening and closure of intraventricular neuroendoscopic procedures in infants under 1 year of age: institutional technique, case series and review of the literature

Purpose: Intraventricular neuroendoscopic techniques, particularly third ventriculostomy, are employed increasingly in the management of infantile hydrocephalus. However, surgical access to the ventricular cavities is associated with a risk of post-operative cerebrospinal fluid (CSF) leak. Here, we describe a structured, multi-layered approach to wound opening and closure which aims to maximise the natural tissue barriers against CSF leakage. We present a series of patients undergoing this technique and subsequently review the literature regarding opening and closure techniques in paediatric intraventricular neuroendoscopic procedures. Methods: We performed a retrospective case series analysis of patients under 1 year of age who underwent intraventricular neuroendoscopic procedures in a single institution over a 5-year period. Patients were identified from an institutional operative database, and operation notes and clinical records were subsequently reviewed. Results: 28 patients fulfilled the inclusion criteria for this study. The mean age at operation was 9 weeks. 27 patients underwent endoscopic third ventriculostomy whilst 1 underwent endoscopic septostomy, and all patients underwent our structured, multi-layered opening and closure technique. Follow-up ranged from 4 months to 5 years. There were no cases of post-operative CSF leak, infection or wound breakdown. 12 patients remained shunt-free at the last follow-up, with the remaining 16 requiring shunt insertion for progressive hydrocephalus at a mean of 24 days post-operatively. Conclusion: Various methods aiming to prevent post-operative CSF leak have been reported in the literature. We propose that our institutional technique may be of benefit in minimising this risk in infants undergoing endoscopic third ventriculostomy and similar intraventricular neuroendoscopic procedures

The landscape of inherited and de novo copy number variants in a plasmodium falciparum genetic cross

<p>Abstract</p> <p>Background</p> <p>Copy number is a major source of genome variation with important evolutionary implications. Consequently, it is essential to determine copy number variant (CNV) behavior, distributions and frequencies across genomes to understand their origins in both evolutionary and generational time frames. We use comparative genomic hybridization (CGH) microarray and the resolution provided by a segregating population of cloned progeny lines of the malaria parasite, <it>Plasmodium falciparum</it>, to identify and analyze the inheritance of 170 genome-wide CNVs.</p> <p>Results</p> <p>We describe CNVs in progeny clones derived from both Mendelian (i.e. inherited) and non-Mendelian mechanisms. Forty-five CNVs were present in the parent lines and segregated in the progeny population. Furthermore, extensive variation that did not conform to strict Mendelian inheritance patterns was observed. 124 CNVs were called in one or more progeny but in neither parent: we observed CNVs in more than one progeny clone that were not identified in either parent, located more frequently in the telomeric-subtelomeric regions of chromosomes and singleton <it>de novo </it>CNVs distributed evenly throughout the genome. Linkage analysis of CNVs revealed dynamic copy number fluctuations and suggested mechanisms that could have generated them. Five of 12 previously identified expression quantitative trait loci (eQTL) hotspots coincide with CNVs, demonstrating the potential for broad influence of CNV on the transcriptional program and phenotypic variation.</p> <p>Conclusions</p> <p>CNVs are a significant source of segregating and <it>de novo </it>genome variation involving hundreds of genes. Examination of progeny genome segments provides a framework to assess the extent and possible origins of CNVs. This segregating genetic system reveals the breadth, distribution and dynamics of CNVs in a surprisingly plastic parasite genome, providing a new perspective on the sources of diversity in parasite populations.</p

Automatic generation of Bond Graph models of process plants

This paper presents an application for the automatic generation of Bond Graph models. The basis for this automated creation is a modified plant model in the XML-format according to the IEC PAS 62424 (CAEX). The application developed in the programming language C, extracts and converts the information which is, then, stored in a model file meeting the requirements and structure of the modelling/simulation-language Dymola. Bond Graphs are used as the modelling technique since they do not distinguish between different energy domains and, therefore, combine several advantages against other modelling techniques. The developed application can be used for multiple purposes such as simulations, visualizations and other specific tasks that might emerge during the planning and operation process of plants and other engineering systems. © 2008 IEEE

Myocardial Regeneration via Progenitor Cell-Derived Exosomes

In the past 20 years, a variety of cell products has been evaluated in terms of their capacity to treat patients with acute myocardial infarction and chronic heart failure. Despite initial enthusiasm, therapeutic efficacy has overall been disappointing, and clinical application is costly and complex. Recently, a subset of small extracellular vesicles (EVs), commonly referred to as “exosomes,” was shown to confer cardioprotective and regenerative signals at a magnitude similar to that of their donor cells. The conceptual advantage is that they may be produced in industrial quantities and stored at the point-of-care for off-the-shelf application, ideally without eliciting a relevant recipient immune response or other adverse effects associated with viable cells. The body of evidence on beneficial exosome-mediated effects in animal models of heart diseases is rapidly growing. However, there is significant heterogeneity in terms of exosome source cells, isolation process, therapeutic dosage, and delivery mode. This review summarizes the current state of research on exosomes as experimental therapy of heart diseases and seeks to identify roadblocks that need to be overcome prior to clinical application

Formation of chromium containing impurities in (La,Sr)MnO3_{3} solid-oxide-fuel-cell cathodes under stack operating conditions and its effect on performance

In this study, we present an investigation of the chromium-related electrical performance degradation of anode-supported SOFCs with a LSM/YSZ composite cathode. A traditional ferritic interconnect steel with high chromium content is established as the primary chromium source and chromium poisoning of the cathode is carried out at relevant SOFC operating conditions. The prolonged influence of the gaseous chromium species on the cell performance and cathode microstructure under constant current conditions was examined quantitatively. Physical deposition of chromium(III) compounds (mainly spinel-type (Cr,Mn)3O4 phases) was observed at the electrochemically active region adjacent to the electrolyte only under realistic constant current conditions. The microstructural degradation associated with the formation of secondary phases correlated directly with the performance degradation, the effective chromium partial pressure and the current density. Furthermore, the influence of the presence of a number of protecting layers on the interconnect steel was evaluated with regard to the cathode poisoning. It was shown that chromium-induced degradation was reduced drastically when an additional manganese reservoir layer and a Cr getter layer were applied