ABSTRACT
A patient suffering from juvenile myoclonic epilepsy experienced myoclonic jerks, fairly regularly, while playing chess. The myoclonus appeared particularly when he had to plan his strategy, to choose between two solutions or while raising the arm to move a chess figure. Video-EEG-polygraphy was performed, with back averaging of the myoclonus registered during a chess match and during neuropsychological testing with Kohs cubes. The EEG spike wave complexes were localised in the fronto-central region. [Published with video sequences].
Subject(s)
Electroencephalography , Epilepsies, Myoclonic/diagnosis , Epilepsy, Reflex/diagnosis , Play and Playthings , Signal Processing, Computer-Assisted , Video Recording , Adult , Anticonvulsants/therapeutic use , Attention/drug effects , Attention/physiology , Electroencephalography/drug effects , Electromyography/drug effects , Epilepsies, Myoclonic/drug therapy , Epilepsies, Myoclonic/physiopathology , Epilepsy, Reflex/drug therapy , Epilepsy, Reflex/physiopathology , Evoked Potentials/drug effects , Evoked Potentials/physiology , Frontal Lobe/drug effects , Frontal Lobe/physiopathology , Games, Experimental , Humans , Male , Neuropsychological Tests , Problem Solving/drug effects , Problem Solving/physiology , Psychomotor Performance/drug effects , Psychomotor Performance/physiology , Valproic Acid/therapeutic useABSTRACT
X inactivation in female mammals is controlled by a key locus on the X chromosome, the X-inactivation center (Xic). The Xic controls the initiation and propagation of inactivation in cis. It also ensures that the correct number of X chromosomes undergo inactivation (counting) and determines which X chromosome becomes inactivated (choice). The Xist gene maps to the Xic region and is essential for the initiation of X inactivation in cis. Regulatory elements of X inactivation have been proposed to lie 3' to Xist. One such element, lying 15 kb downstream of Xist, is the DXPas34 locus, which was first identified as a result of its hypermethylation on the active X chromosome and the correlation of its methylation level with allelism at the X-controlling element (Xce), a locus known to affect choice. In this study, we have tested the potential function of the DXPas34 locus in Xist regulation and X-inactivation initiation by deleting it in the context of large Xist-containing yeast artificial chromosome transgenes. Deletion of DXPas34 eliminates both Xist expression and antisense transcription present in this region in undifferentiated ES cells. It also leads to nonrandom inactivation of the deleted transgene upon differentiation. DXPas34 thus appears to be a critical regulator of Xist activity and X inactivation. The expression pattern of DXPas34 during early embryonic development, which we report here, further suggests that it could be implicated in the regulation of imprinted Xist expression.
Subject(s)
Gene Expression Regulation , RNA, Untranslated , Regulatory Sequences, Nucleic Acid , Transcription Factors/genetics , X Chromosome , Animals , Cell Differentiation , Cell Line , Chromosomes, Artificial, Yeast , CpG Islands , Embryonic and Fetal Development , Female , In Situ Hybridization, Fluorescence , Male , Mice , Microsatellite Repeats , RNA, Long Noncoding , Reverse Transcriptase Polymerase Chain Reaction , Transcription, Genetic , TransgenesABSTRACT
The overall organization of the X-inactivation center (XIC/Xic) candidate region seems poorly conserved between human and mouse. The orientation of a region containing the X-inactive-specific transcript (Xist/ XIST) gene and three genes located 3' of Xist/XIST has been shown to be inverted between the two species, although the actual extent of this rearrangement is unknown. We have cloned and mapped the mouse homolog of the human XPCT (X-linked PEST-containing transporter) gene, which encodes a putative transmembrane transporter. Human XPCT is located about 200 kb outside of the XIC candidate region and 600 kb 5' of or telomeric to the XIST gene. The mouse Xpct gene, which lies approximately 300 kb 5' of and centromeric to Xist, displays 85% identity at the nucleotide level with the human gene, and the overall protein structure is conserved. The transcriptional orientation of mouse Xpct with respect to Xist is the opposite of that in human. Consequently, the evolution of the region between human and mouse appears to be highly complex, with structural rearrangements involving a region of up to 600 kb or more around the Xist gene.
Subject(s)
Carrier Proteins/genetics , Evolution, Molecular , Gene Rearrangement , Membrane Proteins/genetics , Membrane Transport Proteins , Monocarboxylic Acid Transporters , X Chromosome , Amino Acid Sequence , Animals , Blotting, Northern , Chromosome Mapping , Cloning, Molecular , DNA, Complementary , Humans , Mice , Molecular Sequence Data , Restriction Mapping , Sequence Alignment , Sequence Homology, Amino Acid , SymportersABSTRACT
In order to assess the relative sensitivity and specificity of Katzman's short orientation memory concentration test (OMCT), 89 non demented patients and 44 patients affected by vascular or degenerative dementia were consecutively evaluated by three different mental status tests. The OMCT appeared equivalent to the Mini Mental State Examination in identifying dementia. Optimum sensitivity and specificity, respectively 88% and 94%, were achieved by a 10/11 cut-off score, giving a 11% false positive rate. Among patients with Alzheimer's disease, the OMCT score was correlated with mean values of a simple reaction time. It was also correlated with the Wechsler global MQ and the orientation, logical memory and paired associates items of the scale. There was no relationship between the OMCT score and the coloured Progressive Matrices IQ. The OMCT was reliable when given at 1 month interval. Serial evaluations did not show any significant practice effect.
