9 research outputs found

    Epilepsy Caused by an Abnormal Alternative Splicing with Dosage Effect of the SV2A Gene in a Chicken Model

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    Photosensitive reflex epilepsy is caused by the combination of an individual's enhanced sensitivity with relevant light stimuli, such as stroboscopic lights or video games. This is the most common reflex epilepsy in humans; it is characterized by the photoparoxysmal response, which is an abnormal electroencephalographic reaction, and seizures triggered by intermittent light stimulation. Here, by using genetic mapping, sequencing and functional analyses, we report that a mutation in the acceptor site of the second intron of SV2A (the gene encoding synaptic vesicle glycoprotein 2A) is causing photosensitive reflex epilepsy in a unique vertebrate model, the Fepi chicken strain, a spontaneous model where the neurological disorder is inherited as an autosomal recessive mutation. This mutation causes an aberrant splicing event and significantly reduces the level of SV2A mRNA in homozygous carriers. Levetiracetam, a second generation antiepileptic drug, is known to bind SV2A, and SV2A knock-out mice develop seizures soon after birth and usually die within three weeks. The Fepi chicken survives to adulthood and responds to levetiracetam, suggesting that the low-level expression of SV2A in these animals is sufficient to allow survival, but does not protect against seizures. Thus, the Fepi chicken model shows that the role of the SV2A pathway in the brain is conserved between birds and mammals, in spite of a large phylogenetic distance. The Fepi model appears particularly useful for further studies of physiopathology of reflex epilepsy, in comparison with induced models of epilepsy in rodents. Consequently, SV2A is a very attractive candidate gene for analysis in the context of both mono- and polygenic generalized epilepsies in humans

    Secondary rhinoplasty in the bilateral cleft.

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    Secondary rhinoplasty in bilateral clefts is very complex due to its specific pathological anatomical characteristics. In this article, the general and specific characteristics of the nose of the bilateral clefts are described and careful preoperative assessment is emphasized. We discuss the timing of the operation considering growth inhibition and psychological aspects and a systematic rational surgical approach, dividing the operative procedure into: septal surgery, tip surgery, osseocartilaginous vault surgery, maxillary augmentation, and alar base reallocation. We report results of a retrospective study to evaluate the postoperative care with a custom-made vestibulum device to prevent stenosis of the vestibulum caused by scar tissue retraction in the postoperative perio

    Differences in Cartilage-Forming Capacity of Expanded Human Chondrocytes From Ear and Nose and Their Gene Expression Profiles

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    The aim of this study was to evaluate the potential of culture-expanded human auricular and nasoseptal chondrocytes as cell source for regeneration of stable cartilage and to analyze the differences in gene expression profile of expanded chondrocytes from these specific locations. Auricular chondrocytes in monolayer proliferated less and more slowly (two passages took 26.7 +/- 2.1 days and were reached in 4.37 +/- 0.30 population doublings) than nasoseptal chondrocytes (19.3 +/- 2.5 days: 5.45 +/- 0.20 population doublings). However, auricular chondrocytes produced larger pellets with more cartilage-like matrix than nasoseptal chondrocytes (2.2 +/- 0.71 vs. 1.7 +/- 0.13 mm in diameter after 35 days of culture). Although the matrix formed by auricular and nasoseptal chondrocytes contained collagen X, it did not mineralize in an in vitro model or after in vivo subcutaneous implantation. A DNA microarray study on expanded auricular and nasoseptal chondrocytes from the same donors revealed 1,090 differentially expressed genes. No difference was observed in the expression of known markers of chondrogenic capacity (e.g., collagen II, FGFR3, BMP2, and ALK1). The most striking differences were that the auricular chondrocytes had a higher expression of anabolic growth factors BMP5 and IGF1, while matrix-degrading enzymes MMP13 and ADAMTS5 were higher expressed in nasoseptal chondrocytes. This might offer a possible explanation for the observed higher matrix production by auricular chondrocytes. Moreover, chondrocytes isolated from auricular or nasoseptal cartilage had specific gene expression profiles even after expansion. These differently expressed genes were not restricted to known characterization of donor site subtype (e.g., elastic), but were also related to developmental processes

    GWAS meta-analysis of over 29,000 people with epilepsy identifies 26 risk loci and subtype-specific genetic architecture

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