Antibodies to clustered acetylcholine receptor: expanding the phenotype.

BACKGROUND AND PURPOSE: To provide a detailed phenotypical description of seronegative patients with generalized myasthenia gravis and antibodies to clustered acetylcholine receptors (AChRs) and to assess their frequency amongst a French seronegative generalized myasthenia gravis (SNMG) population. METHODS: A French SNMG database was created and the sera from the 37 patients included in it were analysed by immunofluorescence of cell-based assays using cotransfection of AChR subunit genes together with rapsyn to densely cluster the AChRs. RESULTS: Sixteen per cent (n = 6) of the SNMG patients were found to have antibodies to clustered AChR. They presented either with early onset MG and thymic hyperplasia, late onset MG and thymic involution, or thymoma associated MG. They responded well to cholinesterase inhibitors and immunosuppressants. CONCLUSIONS: Patients with antibodies to clustered AChR account for a significant proportion of SNMG patients and resemble patients with AChR antibodies detected by standard radio-immunoprecipitation.

Assessment of Clinical Meaningfulness of Endpoints in the Generation Program by the Insights to Model Alzheimer's Progression in Real Life (iMAP) Study.

We are launching the Insights to Model Alzheimer's Progression in Real Life study in parallel with the Alzheimer Prevention Initiative Generation Program. This is a 5-year, multinational, prospective, longitudinal, non-interventional cohort study that will collect data across the spectrum of Alzheimer's disease. The primary objective is to assess the ability of the Alzheimer's Prevention Initiative Cognitive Composite Test Score and Repeatable Battery for the Assessment of Neuropsychological Status to predict clinically meaningful outcomes such as diagnosis of mild cognitive impairment or dementia due to Alzheimer's disease, and change in Clinical Dementia Rating - Global Score. This study is the first large-scale, prospective effort to establish the clinical meaningfulness of cognitive test scores that track longitudinal decline in preclinical Alzheimer's disease. This study is also expected to contribute to our understanding of the relationships among outcomes in different stages of Alzheimer's disease as well as models of individual trajectories during the course of the disease.

Identification of a new gene family specifically expressed in chicken embryonic stem cells and early embryo.

Chicken embryonic stem (CES) cells are pluripotent cells derived from chicken early blastoderm. In order to identify new genes specifically expressed in these pluripotent cells, we have used a gene trap strategy and cloned a novel gene family called cENS for chicken Embryonic Normal Stem cell gene. The cENS genes expression decreases after induction of CES cells differentiation in culture and is restricted in vivo to the very early embryo. We have characterized three different cENS genes. One, cENS-1, is composed of an open reading frame inserted between two terminal direct repeats which are the common point of the cENS genes. cENS-1 encodes a protein identical to cERNI, a recently described protein. cENS-2 is a truncated form of cENS-1. cENS-3 presents two adjacent open reading frames coding respectively for env and pol related proteins. The presence of conserved direct repeats, of retrovirus related genes and the absence of introns argue in favor of a retroviral origin of the cENS genes. In the cENS we identified a promoter region whose activity is strong in CES cells and decreases after induced differentiation showing a highly specific transcriptional activity specific of undifferentiated chicken embryonic stem cells.