Widespread occurrence of non-canonical transcription termination by human RNA polymerase III

Human RNA polymerase (Pol) III-transcribed genes are thought to share a simple termination signal constituted by four or more consecutive thymidine residues in the coding DNA strand, just downstream of the RNA 3′-end sequence. We found that a large set of human tRNA genes (tDNAs) do not display any T≥4 stretch within 50 bp of 3′-flanking region. In vitro analysis of tDNAs with a distanced T≥4 revealed the existence of non-canonical terminators resembling degenerate T≥5 elements, which ensure significant termination but at the same time allow for the production of Pol III read-through pre-tRNAs with unusually long 3′ trailers. A panel of such non-canonical signals was found to direct transcription termination of unusual Pol III-synthesized viral pre-miRNA transcripts in gammaherpesvirus 68-infected cells. Genome-wide location analysis revealed that human Pol III tends to trespass into the 3′-flanking regions of tDNAs, as expected from extensive terminator read-through. The widespread occurrence of partial termination suggests that the Pol III primary transcriptome in mammals is unexpectedly enriched in 3′-trailer sequences with the potential to contribute novel functional ncRNA

Widespread occurrence of non-canonical transcription termination by human RNA polymerase III

Human RNA polymerase (Pol) III-transcribed genes are thought to share a simple termination signal constituted by four or more consecutive thymidine residues in the coding DNA strand, just downstream of the RNA 3′-end sequence. We found that a large set of human tRNA genes (tDNAs) do not display any T≥4 stretch within 50 bp of 3′-flanking region. In vitro analysis of tDNAs with a distanced T≥4 revealed the existence of non-canonical terminators resembling degenerate T≥5 elements, which ensure significant termination but at the same time allow for the production of Pol III read-through pre-tRNAs with unusually long 3′ trailers. A panel of such non-canonical signals was found to direct transcription termination of unusual Pol III-synthesized viral pre-miRNA transcripts in gammaherpesvirus 68-infected cells. Genome-wide location analysis revealed that human Pol III tends to trespass into the 3′-flanking regions of tDNAs, as expected from extensive terminator read-through. The widespread occurrence of partial termination suggests that the Pol III primary transcriptome in mammals is unexpectedly enriched in 3′-trailer sequences with the potential to contribute novel functional ncRNAs

Computer Assisted Training of Attention and Concentration with Healty Children

Ziel der Untersuchungen war es, ein im klinischen Einsatz bei Erwachsenen mit Hirnschädigungen entwickeltes computergestütztes Aufmerksamkeitstraining (System RehaCom) für den Einsatz in der Behandlung von Kindern zu erproben. Dabei wurde das Verfahren an normalgesunden Kindern verschiedener Altersgruppen evaluiert. Die gewonnenen Erfahrungen sollen helfen, die Trainingsverfahren für hirngeschädigte Kinder zu erschließen und anzupassen. In bezug auf erhobene Leistungsparameter des Trainings (erreichtes Leistungsniveau) unterscheiden sich die Altersgruppen signifikant im Verlauf. Schulkinder profitieren im Vergleich zu Kindergartenkindern in höherem Maße von dem Training. Implikationen für Veränderungen des Trainingsprogramms werden diskutiert. Weitere Leistungsparameter (Reaktionszeiten, Fehler) geben Hinweise auf die Schwierigkeitsstruktur des Programms. Fragebogenerhebungen zur Motivation vor und während des Trainings, Aufgabenverständlichkeit, Bedienerfreundlichkeit sowie bezüglich der Kindgerechtheit der verwendeten Bilder ergaben, daß eine Aufrechterhaltung der Motivation etwa durch ein leistungsadaptives Trainieren positiv beeinflusst wird: die Kinder sollten nicht durch zu leichte Aufgaben demotiviert und durch zu schwere Aufgaben frustriert werden. Insgesamt war die Akzeptanz gegenüber dem computergestützten kognitiven Training gut. Die Anwesenheit eines Therapeuten während des Trainings ist bei Kindern unter sechs Jahren unbedingt erforderlich.(DIPF/Orig.)The intention of this study was to analyze in how far a computer assisted training for brain damaged adults can be used for the practice with children. Healthy children of different ages were trained with this attention and concentration programme. The results should help to adapt the training programme for the use in brain damaged children. Age-groups differed significantly in level of performance. Data showed that in comparison to Kindergarten-children, first-grade children showed a higher benefit from the training. Implications for modifications of the training-programme are discussed. Other parameter of performance (reactiontime, errors) in relation to school age provide clues to the distribution of structure of difficulty in the programmes. A questionnaire assessing motivation before and during the training, intelligibility of the task, feasibility of the computer and adequacy of the test in children showed that sustained motivation can be achieved provided the training is used in an adaptive way. Thereby demotivating with too easy tasks as well as frustration caused by difficult tasks can be avoided. In general, there was good acceptance of the computerised cognitive training. The presence of a therapist during every training session proved to be necessary in children under the age of 6 years.(DIPF/Orig.

Functional retrograde amnesia: A multiple case study

Fujiwara E, Brand M, Kracht L, et al. Functional retrograde amnesia: A multiple case study. Cortex. 2008;44(1):29-45.Functional retrograde amnesia (RA) is a rare pathology and has been rarely studied in detail across different patients. We extensively examined five functional RA patients and compared their neuropsychological profile including anterograde and retrograde memory performance, executive functions, emotional processing, and formally assessed psychiatric symptoms. Across patients, neuropsychological deficits beyond RA were most consistently seen in executive functions and attention suggesting that these dysfunctions contribute to the remote memory deficit. In a majority of the patients, problems in social cognition and emotional behaviour were reflected in Theory of Mind deficits and accompanying psychiatric symptoms. Aberrances in a measure of social desirability were detected, pointing to repressive tendencies in three out of the five patients. Future studies of functional RA patients may investigate more specifically which frontal-lobe associated (dys-) functions contribute to the memory retrieval deficit. Moreover, studying more closely the interaction between social cognition, repressive personality style and memory inhibition in this disease seems worthwhile pursuing. (c) 2007 Elsevier Masson Srl. All rights reserved