25 research outputs found

    Osseous metaplasia in an ulcerating tubular adenoma of the colon: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Heterotopic bone is rarely found in the gastrointestinal tract. Here we report a rare case of metaplastic ossification within a benign ulcerating adenoma and review the literature concerning the aetiology.</p> <p>Case presentation</p> <p>A 63-year-old woman, who presented with a history of melaena, was found at colonoscopy to have a pedunculated ulcerating polyp. Histological examination demonstrated multiple areas of osseous metaplasia within the polyp stroma.</p> <p>Conclusion</p> <p>Heterotopic ossification in colonic adenomas is a particularly rare phenomenon, with the majority of cases occurring within malignant lesions. The suggested mechanisms for its aetiology still remain unclear.</p

    Functional Analysis of Alleged NOGGIN Mutation G92E Disproves Its Pathogenic Relevance

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    We identified an amino acid change (p.G92E) in the Bone Morphogenetic Protein antagonist NOGGIN in a 22-month-old boy who presented with a unilateral brachydactyly type B phenotype. Brachydactyly type B is a skeletal malformation that has been associated with increased Bone Morphogenetic Protein pathway activation in other patients. Previously, the amino acid change p.G92E in NOGGIN was described as causing fibrodysplasia ossificans progressiva, a rare genetic disorder characterized by limb malformations and progressive heterotopic bone formation in soft tissues that, like Brachydactyly type B, is caused by increased activation of Bone Morphogenetic Protein signaling. To determine whether G92E-NOGGIN shows impaired antagonism that could lead to increased Bone Morphogenetic Protein signaling, we performed functional assays to evaluate inhibition of BMP signaling. Interestingly, wt-NOGGIN shows different inhibition efficacies towards various Bone Morphogenetic Proteins that are known to be essential in limb development. However, comparing the biological activity of G92E-NOGGIN with wt-NOGGIN, we observed that G92E-NOGGIN inhibits activation of bone morphogenetic protein signaling with equal efficiency as wt-NOGGIN, supporting that G92E-NOGGIN does not cause pathological effects. Genetic testing of the child's parents revealed the same amino acid change in the healthy father, further supporting that p.G92E is a neutral amino acid substitution in NOGGIN. We conclude that p.G92E represents a rare polymorphism of the NOGGIN gene - causing neither brachydactyly nor fibrodysplasia ossificans progressiva. This study highlights that a given genetic variation should not be considered pathogenic unless supported by functional analyses

    Methylphenidate Normalizes Fronto-Striatal Underactivation During Interference Inhibition in Medication-Naïve Boys with Attention-Deficit Hyperactivity Disorder

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    Youth with attention deficit hyperactivity disorder (ADHD) have deficits in interference inhibition, which can be improved with the indirect catecholamine agonist methylphenidate (MPH). Functional magnetic resonance imaging was used to investigate the effects of a single dose of MPH on brain activation during interference inhibition in medication-naïve ADHD boys. Medication-naïve boys with ADHD were scanned twice, in a randomized, double-blind design, under either a single clinical dose of MPH or placebo, while performing a Simon task that measures interference inhibition and controls for the oddball effect of low-frequency appearance of incongruent trials. Brain activation was compared within patients under either drug condition. To test for potential normalization effects of MPH, brain activation in ADHD patients under either drug condition was compared with that of healthy age-matched comparison boys. During incongruent trials compared with congruent–oddball trials, boys with ADHD under placebo relative to controls showed reduced brain activation in typical areas of interference inhibition, including right inferior prefrontal cortex, left striatum and thalamus, mid-cingulate/supplementary motor area, and left superior temporal lobe. MPH relative to placebo upregulated brain activation in right inferior prefrontal and premotor cortices. Under the MPH condition, patients relative to controls no longer showed the reduced activation in right inferior prefrontal and striato-thalamic regions. Effect size comparison, furthermore, showed that these normalization effects were significant. MPH significantly normalized the fronto-striatal underfunctioning in ADHD patients relative to controls during interference inhibition, but did not affect medial frontal or temporal dysfunction. MPH therefore appears to have a region-specific upregulation effect on fronto-striatal activation

    Fibrodisplasia ossificante progressiva: relato de caso e achados radiográficos Fibrodysplasia ossificans progressiva: a case report and radiographic findings

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    A fibrodisplasia ossificante progressiva é uma doença genética rara do tecido conjuntivo, caracterizada por ossificação disseminada em tecidos moles e alterações congênitas das extremidades. Sua transmissão é autossômica dominante, com penetrância completa, mas expressão variável. O início ocorre na infância e o envolvimento progressivo axial e da região proximal dos membros leva a uma conseqüente imobilização e deformação articular. Apresentamos um caso de um paciente de 22 anos de idade, do sexo masculino, com quadro clínico característico de fibrodisplasia ossificante progressiva e discutimos os últimos avanços no diagnóstico e na fisiopatogenia desta entidade.<br>Fibrodysplasia ossificans progressiva is a rare hereditary connective tissue disease characterized by disseminated soft tissue ossification and congenital abnormality of the extremities. It is genetically inherited as a dominant trait with complete penetrance but variable expression. The onset takes place during childhood and the progressive involvement of the spine and proximal extremities leads to immobilization and articular deformity. We report a case of a 22-year-old male patient with typical symptoms of fibrodysplasia ossificans progressiva and discuss the new advances in the diagnosis and pathophysiology

    Public Policy Making Process in the United Arab Emirates

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    As “governance” gains momentum as one of the trajectories of the twenty-first century, the interest among ordinary citizens and practitioners in understanding how governments make policies is picking up speed as well. This chapter explores how policy agenda is set, formulated, and comes into law in the United Arab Emirates (UAE). Selected theoretical models of policy making and how each might explain this important activity in the UAE are also examined

    A recurrent mutation in the BMP type I receptor ACVR1 causes inherited and sporadic fibrodysplasia ossificans progressiva

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    Fibrodysplasia ossificans progressiva (FOP) is a rare autosomal dominant disorder of skeletal malformations and progressive extraskeletal ossification. We mapped FOP to chromosome 2q23-24 by linkage analysis and identified an identical heterozygous mutation (617G -> A; R206H) in the glycine-serine (GS) activation domain of ACVR1, a BMP type I receptor, in all affected individuals examined. Protein modeling predicts destabilization of the GS domain, consistent with constitutive activation of ACVR1 as the underlying cause of the ectopic chondrogenesis, osteogenesis and joint fusions seen in FOP
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