Harmonizing neuropsychological assessment for mild neurocognitive disorders in Europe

INTRODUCTION Harmonized neuropsychological assessment for neurocognitive disorders, an international priority for valid and reliable diagnostic procedures, has been achieved only in specific countries or research contexts. METHODS To harmonize the assessment of mild cognitive impairment in Europe, a workshop (Geneva, May 2018) convened stakeholders, methodologists, academic, and non-academic clinicians and experts from European, US, and Australian harmonization initiatives. RESULTS With formal presentations and thematic working-groups we defined a standard battery consistent with the U.S. Uniform DataSet, version 3, and homogeneous methodology to obtain consistent normative data across tests and languages. Adaptations consist of including two tests specific to typical Alzheimer's disease and behavioral variant frontotemporal dementia. The methodology for harmonized normative data includes consensus definition of cognitively normal controls, classification of confounding factors (age, sex, and education), and calculation of minimum sample sizes. DISCUSSION This expert consensus allows harmonizing the diagnosis of neurocognitive disorders across European countries and possibly beyond

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Acquired uniparental isodisomy and other somatic "second-hits" explain why glomuvenous malformations are multifocal

The goal of this thesis project was to unravel pathophysiological mechanisms playing a role in the development of glomuvenous malformations (GVMs). This work focused particularly on mechanisms involved in their multifocal and localized nature, and the involvement of somatic 'second-hit' mutations occurring in the glomulin gene. RNA in situ hybridization, performed in our laboratory, allowed us to determine the beginning of glomulin expression during embryonic development. Glomulin was first detected at embryonic day E10.5 in the cardiac outflow tract. Later, its expression was restricted to vascular smooth muscle cells, with a limited expression in the perichondrium (McIntyre et al, 2004). This likely suggested that the dysfunction, causing GVMs, resides in vascular smooth muscle cells. However, tissue heterogeneity had to be considered. One somatic 'second-hit' mutation had been identified in a resected GVM by our group (Brouillard et al, 2002), allowing us to hypothesize that GVMs are caused by the association of an inherited and a somatic 'second-hit' mutations. This could also explain the phenotypic variability observed within patients of a same family, existence of healthy carriers and apparition of new lesions in time. We collected 19 resected GVMs and identified somatic 'second-hit' mutations in 12 of them, the majority being somatic acquired uniparental isodisomies of the whole chromosome 1 short arm. Another part of this thesis project aimed to identify glomulin-interacting partners and putative signaling pathway(s) in which glomulin could be involved (Annex 1). By using yeast two-hybrid experiments and glomulin as a bait two aliquots of human cardiac cDNA library were screened. However, we did not find validated glomulin-interacting partners.Le but de cette thèse était de découvrir les mécanismes pathophysiologiques impliqués dans le développement des malformations glomuveineuses. Ce travail ciblait les mécanismes pouvant expliquer la nature multifocale et localisée des malformations glomuveineuses, et, tout particulièrement, l'implication des mutations somatiques, dites «second-hit», survenant dans le gène de la glomuline. A l'aide d'expériences d'hybridisation in situ sur l'ARN, nous avons pu déterminer que l'expression de la glomuline commence dès le 10,5ème jour embryonnaire dans les vaisseaux sortant du cœur. Par après, son expression est restreinte aux cellules musculaires lisses vasculaires, mais aussi dans le périchondre (McIntyre et al, 2004). Cela suggère que la dysfonction causant les malformations glomuveineuses réside dans les cellules musculaires lisses vasculaires. Cependant, l'hétérogénéité tissulaire doit aussi être prise en compte. Une mutation somatique, dite «second-hit», a été identifiée par notre groupe dans une malformation glomuveineuse réséquée (Brouillard et al, 2002). Cela nous a permis d'émettre l'hypothèse suivante: les malformations glomuveineuses sont causées par l'association d'une mutation héréditaire et d'une mutation somatique, dite 'second-hit'. Cela peut aussi expliquer les variations du phénotype observées chez les patients d'une même famille, l'existence de porteurs sains et l'apparition de nouvelles lésions au cours du temps. Nous avons collecté 19 malformations glomuveineuses réséquées, et pour 12 d'entre elles, une mutation somatique, dite «second-hit»', a été identifiée. La majorité de ces mutations sont des isodisomies uniparentales acquises impliquant l’entièreté du bras court du chromosome 1. Une autre partie de cette thèse concernait l'identification des partenaires d'interaction de la glomuline et la (les) voie(s) de signalisation potentielle(s) dans laquelle (lesquelles) la glomuline pouvait être impliquée (Annexe 1). En utilisant la méthode du double hybride dans la levure et la glomuline comme appât, deux échantillons d'une bibliothèque d'ADNc ont été criblés. Cependant, nous n'avons pas trouvé des partenaires d'interactions valables pour la glomuline.(SBIM 3) -- UCL, 201

Assessment of the importance of the carbonate pump in surface waters of the Bay of Biscay

Marine carbon research in the past decade has been mainly devoted to the understanding and quantification of processes controlling the fluxes of organic matter in the ocean. Little attention has been paid until now to the particulate inorganic carbon whose net fluxes to the sediments are comparable to those of the organic matter. There remains still a large uncertainty in the production and the fate of biogenic calcium carbonate in the oceanic carbon cycle. In the framework of the Belgian global change programme, we have developed a project devoted to the study of the inorganic carbon cycle in the Bay of Biscay where coccolithophorid blooms occur frequently. The study focuses on processes associated with the oceanic production and dissolution of calcium carbonate, by combining field investigations, laboratory experiments and modelling efforts. The rate of primary production and of calcification by phytoplankton is evaluated by 14C incubation experiments during a coccolithophorid bloom-forming period in the area of investigation. The relative production of organic matter and calcium carbonate in the photic zone along a transect from the continental shelf across the slope to deep waters will be presented. A tentative mass balance of the carbon fluxes for this area will be constructed. These preliminary results confirm the importance that the calcium carbonate pump may play in open ocean

Molecular Genetics of Hereditary Vascular Malformations

Vascular anomalies are divided into vascular tumours (mainly infantile haemangiomas) and vascular malformations. Vascular malformations are subdivided following the type of vessel affected: venous, capillary, arteriovenous and lymphatic. In addition to the pure forms, combined lesions are frequently encountered. Most of these malformations are sporadic, i.e. there is no family history, but familial cases, transmitted as an autosomal dominant or recessive trait, exist. During the last 10 years, the identification of disease-causing genes implicated in the familial forms have resulted in a better classification of vascular anomalies, which has helped in assessment of treatment efficacy. These data have also unravelled the physiological role of the identified proteins during human vascular development

Glomulin is predominantly expressed in vascular smooth muscle cells in the embryonic and adult mouse.

Mutations in the glomulin gene result in dominantly inherited vascular lesions of the skin known as glomuvenous malformations (GVMs). These lesions are histologically distinguished by their distended vein-like channels containing characteristic 'glomus cells', which appear to be incompletely or improperly differentiated vascular smooth muscle cells (VSMCs). The function of glomulin is currently unknown. We studied glomulin expression during murine development (E9.5 days post-coitum until adulthood) by non-radioactive in situ hybridization. Glomulin was first detected at E10.5 dpc in cardiac outflow tracts. Later, it showed strong expression in VSMCs as well as a limited expression in the perichondrium. At E11.5-14.5 dpc glomulin RNA was most abundant in the walls of the large vessels. At E16.5 dpc expression was also detectable in smaller arteries and veins. The high expression of glomulin in murine vasculature suggests an important role for glomulin in blood vessel development and/or maintenance, which is supported by the vascular phenotype seen in GVM patients with mutations in this gene

Synthesis and Characterization of Stable Monodisperse Silica Nanoparticle Sols for in Vitro Cytotoxicity Testing

For the investigation of the interaction of nanoparticles with biomolecules, cells, organs, and animal models there is a need for well-characterized nanoparticle suspensions. In this paper we report the preparation of monodisperse dense amorphous silica nanoparticles (SNP) suspended in physiological media that are sterile and sufficiently stable against aggregation. SNP sols with various particle sizes (2-335 nm) were prepared via base-catalyzed hydrolysis and polymerization of tetraethyl orthosilicate under sterile conditions using either ammonia (Stober process (1) ) or lysine catalyst (Lys-Sil process (2) ). The series was complemented with commercial silica sols (Ludox). Silica nanoparticle suspensions were purified by dialysis and dispersed without using any dispersing agent into cell culture media (Dulbecco's Modified Eagle's medium) containing antibiotics. Particle sizes were determined by dynamic light scattering. SNP morphology, surface area, and porosity were characterized using electron microscopy and nitrogen adsorption. The SNP sols in cell culture medium were stable for several days. The catalytic activity of the SNP in the conversion of hydrogen peroxide into hydroxyl radicals was investigated using electron paramagnetic resonance. The catalytic activity per square meter of exposed silica surface area was found to be independent of particle size and preparation method. Using this unique series of nanoparticle suspensions, the relationship between cytotoxicity and particle size was investigated using human endothelial and mouse monocyte-macrophage cells. The cytotoxicity of the SNP was strongly dependent on particle size and cell type. This unique methodology and the collection of well-characterized SNP will be useful for further in vitro studies exploring the physicochemical determinants of nanoparticle toxicity.status: publishe

Synthesis and Characterization of Stable Monodisperse Silica Nanoparticle Sols for in Vitro Cytotoxicity Testing.

For the investigation of the interaction of nanoparticles with biomolecules, cells, organs, and animal models there is a need for well-characterized nanoparticle suspensions. In this paper we report the preparation of monodisperse dense amorphous silica nanoparticles (SNP) suspended in physiological media that are sterile and sufficiently stable against aggregation. SNP sols with various particle sizes (2-335 nm) were prepared via base-catalyzed hydrolysis and polymerization of tetraethyl orthosilicate under sterile conditions using either ammonia (Stober process (1) ) or lysine catalyst (Lys-Sil process (2) ). The series was complemented with commercial silica sols (Ludox). Silica nanoparticle suspensions were purified by dialysis and dispersed without using any dispersing agent into cell culture media (Dulbecco's Modified Eagle's medium) containing antibiotics. Particle sizes were determined by dynamic light scattering. SNP morphology, surface area, and porosity were characterized using electron microscopy and nitrogen adsorption. The SNP sols in cell culture medium were stable for several days. The catalytic activity of the SNP in the conversion of hydrogen peroxide into hydroxyl radicals was investigated using electron paramagnetic resonance. The catalytic activity per square meter of exposed silica surface area was found to be independent of particle size and preparation method. Using this unique series of nanoparticle suspensions, the relationship between cytotoxicity and particle size was investigated using human endothelial and mouse monocyte-macrophage cells. The cytotoxicity of the SNP was strongly dependent on particle size and cell type. This unique methodology and the collection of well-characterized SNP will be useful for further in vitro studies exploring the physicochemical determinants of nanoparticle toxicity