Hedegaardskaarup8878

BACKGROUND The development of Whole-Exome sequencing (WES) and Whole-Genome sequencing (WGS) for clinical purpose allows now to identify multiple pathogenic variants in a patient with a rare disease. Even when a single causative gene was initially suspected. We present here the case of an 8-year-old patient, with global developmental delay and dysmorphic features, with possibly pathogenic variant in 3 distinct genes. METHODS Trio based exome sequencing was performed thanks to IntegraGen SA (Evry, France), on Illumina HiSeq4000 (Illumina, San Diego, California). Sanger sequencing was performed to confirm variants found. RESULTS WES showed the presence of three possibly deleterious variants KMT2A c.9068delA;p.Gln3023Argfs*3 de novo, PAX3 c.530C>G ;p.Ala177Gly de novo and DLG3 c.127delG;p.Asp43Metfs*22 hemizygous inherited from the mother. KMT2A pathogenic variants are involved in Wiedemann-Steiner syndrome, and PAX3 is the gene responsible for Waardenburg syndrome. DLG3 variants have been described in a non-syndromic X-related intellectual disability. CONCLUSIONS Considering the dysmorphic features and intellectual disability presented by this patient, these three variants were therefore imputed as pathogenic and their association responsible for his phenotype. Dual molecular diagnoses were already found by WES in several cohorts (Yang et al. Posey et al., Rossi & al.) with an average of diagnostic yield of 7%. This case demonstrates and reminds us of the importance of analyzing exomes rigorously and exhaustively because it can explain in some cases ( less then 10%) superimposed traits or blended phenotypes. This article is protected by copyright. learn more All rights reserved.RATIONALE Laser ablation combined with mass spectrometry forms a promising tool for chemical depth profiling of solids. At irradiations near the ablation threshold, high depth resolutions are achieved. However, at these conditions, a large fraction of ablated species is neutral and therefore invisible to the instrument. To compensate for this effect, an additional ionization step can be introduced. METHODS Double pulse laser ablation is frequently used in material sciences to produce shallow craters. We apply double pulse UV fs-Laser Ablation Ionization Mass Spectrometry to investigate the depth profiling performance. The first pulse energy is set to gentle ablation conditions, whereas the second pulse is applied at a delay and a pulse energy promoting highest possible ion yield. RESULTS The experiments are performed on a Cr/Ni multi-layered standard. For a mean ablation rate of ~3 nm/pulse (~72 nJ/pulse), a delay of ~73 ps provided optimal results. By further increasing the energy of the second pulse (5-30% higher with respect to the first pulse) an enhancement of ~10 times the single pulse intensity was achieved. These conditions resulted in mean depth resolutions of ~37 and ~30 nm for the Cr and Ni layers, respectively. CONCLUSIONS It is demonstrated on the thin film standard that the double pulse excitation scheme substantially enhances the chemical depth profiling resolution of LIMS with respect to the single pulse scheme. The post-ionization allows for extraordinarily low ablation rates and for quantitative and stoichiometric analysis of nm thick films/coatings. This article is protected by copyright. All rights reserved.Cow's milk allergy (CMA) may present with IgE-mediated or non-IgE mediated symptoms (1). In the Netherlands, non-IgE mediated CMA in infants is more common (3.5%) than IgE-mediated CMA (1%) (2,3,4). For many years it has been a matter of debate which challenge is best for the diagnosis of food allergy home reintroductions (HR), supervised open food challenges (OFC) or double-blind, placebo-controlled food challenges (DBPCFC) (5,6). This article is protected by copyright. All rights reserved.RATIONALE There has been increased interest in the measurement of δ15 N values in amino acids to gain simultaneous insight into both trophic relationships and the composition of biogeochemical sources utilized by producers at the base of the foodweb. A new combustion reactor design in gas chromatography combustion isotope ratio mass spectrometry equipment has brought to light variable outcomes in performance, highlighting the need for better information about best practices for new systems. METHODS Precision for δ15 N values in amino acids using the single combined oxidation-reduction reactor is improved across a sequence of analyses if the reactor is oxidized for a substantial period (2 h) and subsequently maintained throughout the sequence with 12-17 s seed oxidation prior to each run during gas chromatography-combustion isotope ratio mass spectrometry. A five point calibration curve using amino acids with a range of δ15 N values from -2.4‰ to +61.5‰ was used in combination with a 13-15 amino acid mixture to consistently normalize measurements to internationally calibrated reference materials. RESULTS Combining this oxidation method with normalization techniques using both internal and external standards provided a reliable throughput of ~25 samples per week. It allowed for a reproducible level of precision of less then ±0.5‰, n=10 within a derivatized standard mixture across each sequence and an average sample precision of ±0.27‰ n=3, which is lower than the analytical precision typically associated with δ15 N values for amino acid analysis ( less then ±1‰). CONCLUSIONS A few practical considerations regarding oxidation and conditioning of the combustion reactor allow for increased sequence capacity with the single combined oxidation-reduction reactor. These considerations combined with normalization techniques result in a higher throughput and reduced analytical error during the measurement of δ15 N values in amino acids. This article is protected by copyright. All rights reserved.Glioblastoma multiform (GBM), a lethal brain tumor developing in the white matter of the adult brain, contains a small population of GBM stem cells (GSCs), which potentially cause chemotherapeutic resistance and tumor recurrence. However, the mechanisms underlying the pathogenesis and maintenance of GSCs remain largely unknown. A recent study reported that incorporation of ribosomes and ribosomal proteins into somatic cells promoted lineage trans-differentiation toward multipotency. This study aimed to investigate the mechanism underlying stemness acquisition in GBM cells by focusing on 40S ribosomal protein S6 (RPS6). RPS6 was significantly upregulated in high-grade glioma and localized at perivascular, perinecrotic, and border niches in GBM tissues. siRNA-mediated RPS6 knockdown significantly suppressed the characteristics of GSCs, including their tumorsphere potential and GSC marker expression; STAT3 was downregulated in GBM cells. RPS6 overexpression enhanced the tumorsphere potential of GSCs and these effects were attenuated by STAT3 inhibitor (AG490).