Green Tea Polyphenols Rescue of Brain Defects Induced by Overexpression of DYRK1A

Individuals with partial HSA21 trisomies and mice with partial MMU16 trisomies containing an extra copy of the DYRK1A gene present various alterations in brain morphogenesis. They present also learning impairments modeling those encountered in Down syndrome. Previous MRI and histological analyses of a transgenic mice generated using a human YAC construct that contains five genes including DYRK1A reveal that DYRK1A is involved, during development, in the control of brain volume and cell density of specific brain regions. Gene dosage correction induces a rescue of the brain volume alterations. DYRK1A is also involved in the control of synaptic plasticity and memory consolidation. Increased gene dosage results in brain morphogenesis defects, low BDNF levels and mnemonic deficits in these mice. Epigallocatechin gallate (EGCG) — a member of a natural polyphenols family, found in great amount in green tea leaves — is a specific and safe DYRK1A inhibitor. We maintained control and transgenic mice overexpressing DYRK1A on two different polyphenol-based diets, from gestation to adulthood. The major features of the transgenic phenotype were rescued in these mice

Structure properties and relaxor characteristics of the phases transformation in BaTi0.5(Fe0.33Mo0.17)O3 perovskite ceramic

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Dihydropteridine reductase deficiency in a large consanguineous tunisian family: Clinical, biochemical, and neuropathologic findings

We report the case of a large consanguineous Tunisian family of seven siblings suffering from dihydropteridine reductase deficiency with either typical clinical, biochemical, or autopsy findings. Two cousins also were reported to have the same symptoms. This metabolic disorder is characterized by severe microcephaly, psychomotor regression, and progressive basal ganglia calcifications. Dihydropteridine reductase assay on samples collected from the two brothers still alive did not show measurable activity. The sister and four brothers died between the ages of 3 years and 7 years. A neuropathology study done on the sister showed diffuse demyelination throughout the white matter and spongy vacuolation in the subthalamic nuclei, the superior cerebellar peduncles and the tegmentum tracts of the brain stem. The anterointernal part of the putamen was completely necrotic with nearly total nerve cell loss. Abnormal vascular proliferation and calcification of the walls of small, medium, and large arteries and veins, as well as diffusely scattered pericapillary and isolated calcospherites, were seen in this necrotic region. We think that folate deficiency may be involved in the pathogenesis of the basal ganglia calcification