Laura Braccini | PubMed Health

PubMed2006

[ADHD and multimodal intervention].

During the year 2003, the National Register of the Attention deficit hyperactivity disorder (ADHD) has been implemented in Italy. It was commissioned by the Ministry of Health to the Istituto Superiore di Sanità, which is its leading technical and scientific body, with the aim to set up a sound database gathering detailed information on the prescription of Ritalin at the national level. The latter represents the most diffused elective drug treatment for such an early-onset neuropsychiatric syndrome. To this aim, the more prevalent theories on the pathogenesis of ADHD and the debate on therapy are reviewed and discussed. This paper is aimed at emphasizing that this kind of systematic data gathering of such a Register has not to be meant an unconditional approval of a therapeutical approach based on drug therapy only. Pharmacological therapies may or may not be included within the frame of a multimodal complex treatment plan which should also rely on psychological intervention.

Attention Deficit Disorder with Hyperactivity↗

PubMed2005

The post-transcriptional gene silencing machinery functions independently of DNA methylation to repress a LINE1-like retrotransposon in Neurospora crassa.

Post-transcriptional gene silencing (PTGS) involving small interfering RNA (siRNA)-directed degradation of RNA transcripts and transcriptional silencing via DNA methylation have each been proposed as mechanisms of genome defence against invading nucleic acids, such as transposons and viruses. Furthermore, recent data from plants indicates that many transposons are silenced via a combination of the two mechanisms, and siRNAs can direct methylation of transposon sequences. We investigated the contribution of DNA methylation and the PTGS pathway to transposon control in the filamentous fungus Neurospora crassa. We found that repression of the LINE1-like transposon, Tad, requires the Argonaute protein QDE2 and Dicer, each of which are required for transgene-induced PTGS (quelling) in N.crassa. Interestingly, unlike quelling, the RNA-dependent RNA polymerase QDE1 and the RecQ DNA helicase QDE3 were not required for Tad control, suggesting the existence of specialized silencing pathways for diverse kinds of repetitive elements. In contrast, Tad elements were not significantly methylated and the DIM2 DNA methyltransferase, responsible for all known DNA methylation in Neurospora, had no effect on Tad control. Thus, an RNAi-related transposon silencing mechanism operates during the vegetative phase of N.crassa that is independent of DNA methylation, highlighting a major difference between this organism and other methylation-proficient species.

DNA Methylation↗