28 research outputs found

    De novo mutations in SMCHD1 cause Bosma arhinia microphthalmia syndrome and abrogate nasal development

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    Bosma arhinia microphthalmia syndrome (BAMS) is an extremely rare and striking condition characterized by complete absence of the nose with or without ocular defects. We report here that missense mutations in the epigenetic regulator SMCHD1 mapping to the extended ATPase domain of the encoded protein cause BAMS in all 14 cases studied. All mutations were de novo where parental DNA was available. Biochemical tests and in vivo assays in Xenopus laevis embryos suggest that these mutations may behave as gain-of-function alleles. This finding is in contrast to the loss-of-function mutations in SMCHD1 that have been associated with facioscapulohumeral muscular dystrophy (FSHD) type 2. Our results establish SMCHD1 as a key player in nasal development and provide biochemical insight into its enzymatic function that may be exploited for development of therapeutics for FSHD

    Association of Variants in the SPTLC1 Gene With Juvenile Amyotrophic Lateral Sclerosis

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    Importance: Juvenile amyotrophic lateral sclerosis (ALS) is a rare form of ALS characterized by age of symptom onset less than 25 years and a variable presentation.Objective: To identify the genetic variants associated with juvenile ALS.Design, Setting, and Participants: In this multicenter family-based genetic study, trio whole-exome sequencing was performed to identify the disease-associated gene in a case series of unrelated patients diagnosed with juvenile ALS and severe growth retardation. The patients and their family members were enrolled at academic hospitals and a government research facility between March 1, 2016, and March 13, 2020, and were observed until October 1, 2020. Whole-exome sequencing was also performed in a series of patients with juvenile ALS. A total of 66 patients with juvenile ALS and 6258 adult patients with ALS participated in the study. Patients were selected for the study based on their diagnosis, and all eligible participants were enrolled in the study. None of the participants had a family history of neurological disorders, suggesting de novo variants as the underlying genetic mechanism.Main Outcomes and Measures: De novo variants present only in the index case and not in unaffected family members.Results: Trio whole-exome sequencing was performed in 3 patients diagnosed with juvenile ALS and their parents. An additional 63 patients with juvenile ALS and 6258 adult patients with ALS were subsequently screened for variants in the SPTLC1 gene. De novo variants in SPTLC1 (p.Ala20Ser in 2 patients and p.Ser331Tyr in 1 patient) were identified in 3 unrelated patients diagnosed with juvenile ALS and failure to thrive. A fourth variant (p.Leu39del) was identified in a patient with juvenile ALS where parental DNA was unavailable. Variants in this gene have been previously shown to be associated with autosomal-dominant hereditary sensory autonomic neuropathy, type 1A, by disrupting an essential enzyme complex in the sphingolipid synthesis pathway.Conclusions and Relevance: These data broaden the phenotype associated with SPTLC1 and suggest that patients presenting with juvenile ALS should be screened for variants in this gene.</p

    Best practices in literacy instruction

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    Libro dirigido a profesores en activo o en formación en el área de la alfabetización. Estructurado en cinco partes presenta los últimos estudios sobre el aprendizaje y la enseñanza de la escritura y la lectura, y los aplica de forma práctica desarrollando diferentes estrategias de ayuda para los alumnos, al mismo tiempo que ofrece recomendaciones para orientar la toma de decisiones institucional en la materia. Trata además aspectos como la evaluación, motivación, integración de diferentes tipos de textos y recursos multimedia, la alfabetización de adolescentes y el trabajo con estudiantes de inglés como lengua extranjera.SCBiblioteca de Educación del Ministerio de Educación, Cultura y Deporte; Calle San Agustín, 5 - 3 planta; 28014 Madrid; Tel. +34917748000; [email protected]

    Stromal gene expression defines poor-prognosis subtypes in colorectal cancer

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    Recent molecular classifications of colorectal cancer (CRC) based on global gene expression profiles have defined subtypes displaying resistance to therapy and poor prognosis. Upon evaluation of these classification systems, we discovered that their predictive power arises from genes expressed by stromal cells rather than epithelial tumor cells. Bioinformatic and immunohistochemical analyses identify stromal markers that associate robustly with disease relapse across the various classifications. Functional studies indicate that cancer-associated fibroblasts (CAFs) increase the frequency of tumor-initiating cells, an effect that is dramatically enhanced by transforming growth factor (TGF)-β signaling. Likewise, we find that all poor-prognosis CRC subtypes share a gene program induced by TGF-β in tumor stromal cells. Using patient-derived tumor organoids and xenografts, we show that the use of TGF-β signaling inhibitors to block the cross-talk between cancer cells and the microenvironment halts disease progressio

    Normobaric Hyperoxia is Associated with Increased Cerebral Excitotoxicity After Severe Traumatic Brain Injury.

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    BACKGROUND: Normobaric oxygen therapy is frequently applied in neurocritical care, however, whether supplemental FiO2 has beneficial cerebral effects is still controversial. We examined in patients with severe traumatic brain injury (TBI) the effect of incremental FiO2 on cerebral excitotoxicity, quantified by cerebral microdialysis (CMD) glutamate. METHODS: This was a retrospective analysis of a database of severe TBI patients monitored with CMD and brain tissue oxygen (PbtO2). The relationship of FiO2-categorized into four separate ranges (&lt;40, 41-60, 61-80, and &gt;80 %)-with CMD glutamate was examined using ANOVA with Tukey's post hoc test. RESULTS: A total of 1,130 CMD samples from 36 patients-monitored for a median of 4 days-were examined. After adjusting for brain (PbtO2, intracranial pressure, cerebral perfusion pressure, lactate/pyruvate ratio, Marshall CT score) and systemic (PaCO2, PaO2, hemoglobin, APACHE score) covariates, high FiO2 was associated with a progressive increase in CMD glutamate [8.8 (95 % confidence interval 7.4-10.2) µmol/L at FiO2 &lt; 40 % vs. 12.8 (10.9-14.7) µmol/L at 41-60 % FiO2, 19.3 (15.6-23) µmol/L at 61-80 % FiO2, and 22.6 (16.7-28.5) µmol/L at FiO2 &gt; 80 %; multivariate-adjusted p &lt; 0.05]. The threshold of FiO2-related increase in CMD glutamate was lower for samples with normal versus low PbtO2 &lt; 20 mmHg (FiO2 &gt; 40 % vs. FiO2 &gt; 60 %). Hyperoxia (PaO2 &gt; 150 mmHg) was also associated with increased CMD glutamate (adjusted p &lt; 0.001). CONCLUSIONS: Incremental normobaric FiO2 levels were associated with increased cerebral excitotoxicity in patients with severe TBI, independent from PbtO2 and other important cerebral and systemic determinants. These data suggest that supra-normal oxygen may aggravate secondary brain damage after severe TBI
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