Down syndrome (DS) is the most frequent chromosomal disorder. It is caused by the triplication of human chromosome 21, leading to increased dosage of a variety of genes including APP (Amyloid Precursor Protein). Mainly for this reason, individuals with DS are at high risk to develop Alzheimer's disease (AD). Extensive literature identified various morphological and molecular abnormalities in the endo-lysosomal pathway both in DS and AD. Most studies in this field investigated the causative role of APP (Amyloid Precursor Protein) in endo-lysosomal dysfunctions, thus linking phenotypes observed in DS and AD. In DS context, several lines of evidence and emerging hypotheses suggest that other molecular players and pathways may be implicated in these complex phenotypes. In this review, we outline the normal functioning of endosomal trafficking and summarize the research on endo-lysosomal dysfunction in DS in light of AD findings. We emphasize the role of genes of chromosome 21 implicated in endocytosis to explain endosomal abnormalities and set the limitations and perspectives of models used to explore endo-lysosomal dysfunction in DS and find new biomarkers. The review highlights the complexity of endo-lysosomal dysfunction in DS and suggests directions for future research in the field. © 2020 Elsevier B.V. All rights reserved.People who have Down syndrome are at significantly elevated risk of developing early onset Alzheimer's disease that causes dementia (AD-DS). Here we review recent progress in modeling the development of AD-DS in mouse models. These studies provide insight into mechanisms underlying Alzheimer's disease and generate new clinical research questions. In addition, they suggest potential new targets for disease prevention therapies. © 2020 Elsevier B.V. All rights reserved.Down syndrome (DS), caused by trisomy of chromosome 21 (Hsa21), results in a spectrum of phenotypes including learning and memory deficits, motor dysfunction and social constrains. The regions on Hsa21 are conserved with their synteny on mouse chromosome 10, 16 and 17. To date, a wide range of mouse models has been developed to determine genotype-phenotype relationships and identity of the causative dosage-sensitive genes. However, the comparison of behavioral results is not obvious due to the lack of consistency in the genetics background, housing conditions and behavioral protocols used. There is a growing need to standardize some of the classical behavioral test, include automated behavioral phenotyping and sophisticated analysis techniques and move through ethologically inspired tests. Here we present an overview of the status of behavioral phenotyping of DS murine models and the limitations and possibilities to improve their characterization to address genotype-phenotype relationships for understanding the pathophysiology of DS. © 2020 Elsevier B.V. All rights reserved.The presence of an extra copy of human chromosome 21 (Hsa21) leads to a constellation of phenotypic manifestations in Down syndrome (DS), including prominent effects on the brain and immune system. Intensive efforts to unravel the molecular mechanisms underlying these phenotypes may help developing effective therapies, both in DS and in the general population. Here we review recent progress in genetic and epigenetic analysis of trisomy 21 (Ts21). New mouse models of DS based on syntenic conservation of segments of the mouse and human chromosomes are starting to clarify the contributions of chromosomal subregions and orthologous genes to specific phenotypes in DS. The expression of genes on Hsa21 is regulated by epigenetic mechanisms, and with recent findings of highly recurrent gene-specific changes in DNA methylation patterns in brain and immune system cells with Ts21, the epigenomics of DS has become an active research area. Here we highlight the value of combining human studies with mouse models for defining DS critical genes and understanding the trans-acting effects of a simple chromosomal aneuploidy on genome-wide epigenetic patterning. These genetic and epigenetic studies are starting to uncover fundamental biological mechanisms, leading to insights that may soon become therapeutically relevant. © 2020 Elsevier B.V. All rights reserved.BACKGROUND Investigations of myelin oligodendrocyte glycoprotein (MOG) antibodies are usually focused on demyelinating syndromes, but the entire spectrum of MOG antibody-associated syndromes in children is unknown. In this study, we aimed to determine the frequency and distribution of paediatric demyelinating and encephalitic syndromes with MOG antibodies, their response to treatment, and the phenotypes associated with poor prognosis. METHODS In this prospective observational study, children with demyelinating syndromes and with encephalitis other than acute disseminated encephalomyelitis (ADEM) recruited from 40 secondary and tertiary centres in Spain were investigated for MOG antibodies. All MOG antibody-positive cases were included in our study, which assessed syndromes, treatment and response to treatment (ie, number of relapses), outcomes (measured with the modified Rankin scale [mRS]), and phenotypes associated with poor prognosis. We used Fisher's exact and Wilcoxon rank sum tests to analyse clinical fLEX.  https://www.selleckchem.com/products/PLX-4032.html  Chronic hepatitis B virus (HBV) infection follows a dynamic and variable course. At different stages in the disease, hepatitis flares might occur, which can be challenging to predict and manage. Flares are believed to be primarily immune-mediated and might mark transitions to inactive disease or clearance of infection, but in certain scenarios they might also lead to hepatic decompensation or death. As such, understanding of the clinical significance of flares in different patient populations and different scenarios is important for optimal management. In this Review, we summarise what is known about flares in different stages of chronic HBV infection; describe flares in the context of the natural history of chronic infection; summarise the immunological mechanisms underlying flares, and describe flares in different clinical scenarios. Each section reviews existing knowledge and highlights key unanswered questions that need to be addressed to improve the understanding of flares, hopefully providing insights into their pathogenesis that can be used to improve current clinical management and ideally to further develop new curative therapeutic approaches for HBV infection.