79 research outputs found

    Serial Observations and Mutational Analysis of an Adoptee with Family History of Hypertrophic Cardiomyopathy

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    Hypertrophic cardiomyopathy (HCM) is an inherited cardiac disease with an autosomal dominant mode of transmission. Comprehensive genetic screening of several genes frequently found mutated in HCM is recommended for first-degree relatives of HCM patients. Genetic testing provides the means to identify those at risk of developing HCM and to institute measures to prevent sudden cardiac death (SCD). Here, we present an adoptee whose natural mother and maternal relatives were known be afflicted with HCM and SCD. The proband was followed closely from age 6 to 17 years, revealing a natural history of the progression of clinical findings associated with HCM. Genetic testing of the proband and her natural mother, who is affected by HCM, revealed that they were heterozygous for both the R719Q and T1513S variants in the cardiac beta-myosin heavy chain (MYH7) gene. The proband's ominous family history indicates that the combination of the R719Q and T1513S variants in cis may be a “malignant” variant that imparts a poor prognosis in terms of the disease progression and SCD risk

    Creation of a novel algorithm to identify patients with Becker and Duchenne muscular dystrophy within an administrative database and application of the algorithm to assess cardiovascular morbidity

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    BACKGROUND: Outcome analyses in large administrative databases are ideal for rare diseases such as Becker and Duchenne muscular dystrophy. Unfortunately, Becker and Duchenne do not yet have specific International Classification of Disease-9/-10 codes. We hypothesised that an algorithm could accurately identify these patients within administrative data and improve assessment of cardiovascular morbidity. METHODS: Hospital discharges (n=13,189) for patients with muscular dystrophy classified by International Classification of Disease-9 code: 359.1 were identified from the Pediatric Health Information System database. An identification algorithm was created and then validated at three institutions. Multi-variable generalised linear mixed-effects models were used to estimate the associations of length of stay, hospitalisation cost, and 14-day readmission with age, encounter severity, and respiratory disease accounting for clustering within the hospital. RESULTS: The identification algorithm improved identification of patients with Becker and Duchenne from 55% (code 359.1 alone) to 77%. On bi-variate analysis, left ventricular dysfunction and arrhythmia were associated with increased cost of hospitalisation, length of stay, and mortality (p<0.001). After adjustment, Becker and Duchenne patients with left ventricular dysfunction and arrhythmia had increased length of stay with rate ratio 1.4 and 1.2 (p<0.001 and p=0.004) and increased cost of hospitalization with rate ratio 1.4 and 1.4 (both p<0.001). CONCLUSIONS: Our algorithm accurately identifies patients with Becker and Duchenne and can be used for future analysis of administrative data. Our analysis demonstrates the significant effects of cardiovascular disease on length of stay and hospitalisation cost in patients with Becker and Duchenne. Better recognition of the contribution of cardiovascular disease during hospitalisation with earlier more intensive evaluation and therapy may help improve outcomes in this patient population

    A criança asmática: Relação e terreno alérgico.

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    Relata-se o caso clínico de uma criança com asma alérgica. Efectua-se uma abordagem compreensiva através do modelo multidimensional de somatização proposto por Sami-Ali.ABSTRACT: Clinical report on a case study of a child with a psychosomatic disorder: bronquial asthma. The main focus of this paper is on an approach based on the Sami-Ali's somatization multidimensional model.info:eu-repo/semantics/publishedVersio

    Dynamic susceptibility contrast MRI with localized arterial input functions

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    Compared to gold-standard measurements of cerebral perfusion with positron emission tomography (PET) using H2[15O] tracers, measurements with dynamic susceptibility contrast (DSC) MR are more accessible, less expensive and less invasive. However, existing methods for analyzing and interpreting data from DSC MR have characteristic disadvantages that include sensitivity to incorrectly modeled delay and dispersion in a single, global arterial input function (AIF). We describe a model of tissue microcirculation derived from tracer kinetics which estimates for each voxel a unique, localized AIF (LAIF). Parameters of the model were estimated using Bayesian probability theory and Markov-chain Monte Carlo, circumventing difficulties arising from numerical deconvolution. Applying the new method to imaging studies from a cohort of fourteen patients with chronic, atherosclerotic, occlusive disease showed strong correlations between perfusion measured by DSC MR with LAIF and perfusion measured by quantitative PET with H2[15O]. Regression to PET measurements enabled conversion of DSC MR to a physiological scale. Regression analysis for LAIF gave estimates of a scaling factor for quantitation which described perfusion accurately in patients with substantial variability in hemodynamic impairment

    Loss-of-function mutations in the X-linked biglycan gene cause a severe syndromic form of thoracic aortic aneurysms and dissections.

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    Thoracic aortic aneurysm and dissection (TAAD) is typically inherited in an autosomal dominant manner, but rare X-linked families have been described. So far, the only known X-linked gene is FLNA, which is associated with the periventricular nodular heterotopia type of Ehlers-Danlos syndrome. However, mutations in this gene explain only a small number of X-linked TAAD families. We performed targeted resequencing of 368 candidate genes in a cohort of 11 molecularly unexplained Marfan probands. Subsequently, Sanger sequencing of BGN in 360 male and 155 female molecularly unexplained TAAD probands was performed. We found five individuals with loss-of-function mutations in BGN encoding the small leucine-rich proteoglycan biglycan. The clinical phenotype is characterized by early-onset aortic aneurysm and dissection. Other recurrent findings include hypertelorism, pectus deformity, joint hypermobility, contractures, and mild skeletal dysplasia. Fluorescent staining revealed an increase in TGF-β signaling, evidenced by an increase in nuclear pSMAD2 in the aortic wall. Our results are in line with those of prior reports demonstrating that Bgn-deficient male BALB/cA mice die from aortic rupture. In conclusion, BGN gene defects in humans cause an X-linked syndromic form of severe TAAD that is associated with preservation of elastic fibers and increased TGF-β signaling.Genet Med 19 4, 386-395

    Variants in ADRB1 and CYP2C9: Association with Response to Atenolol and Losartan in Marfan Syndrome

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    Objective: To test whether variants in ADRB1 and CYP2C9 genes identify subgroups of individuals with differential response to treatment for Marfan syndrome through analysis of data from a large, randomized trial. Study design: In a subset of 250 white, non-Hispanic participants with Marfan syndrome in a prior randomized trial of atenolol vs losartan, the common variants rs1801252 and rs1801253 in ADRB1 and rs1799853 and rs1057910 in CYP2C9 were analyzed. The primary outcome was baseline-adjusted annual rate of change in the maximum aortic root diameter z-score over 3 years, assessed using mixed effects models. Results: Among 122 atenolol-assigned participants, the 70 with rs1801253 CC genotype had greater rate of improvement in aortic root z-score compared with 52 participants with CG or GG genotypes (Time × Genotype interaction P = .005, mean annual z-score change ± SE -0.20 ± 0.03 vs -0.09 ± 0.03). Among participants with the CC genotype in both treatment arms, those assigned to atenolol had greater rate of improvement compared with the 71 of the 121 assigned to losartan (interaction P = .002; -0.20 ± 0.02 vs -0.07 ± 0.02; P < .001). There were no differences in atenolol response by rs1801252 genotype or in losartan response by CYP2C9 metabolizer status. Conclusions: In this exploratory study, ADRB1-rs1801253 was associated with atenolol response in children and young adults with Marfan syndrome. If these findings are confirmed in future studies, ADRB1 genotyping has the potential to guide therapy by identifying those who are likely to have greater therapeutic response to atenolol than losartan

    Activation of molecular hydrogen and olefins in solution by triphenylphosphine complexes of bivalent ruthenium

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    Kinetic and equilibrium studies involving solutions of dichlorotris-(triphenylphosphine)ruthenium(II) and the corresponding hydridochloro complex are described, especially reactions involving molecular hydrogen and olefins. In benzene or in dimethylacetamide (DMA) solution, the dichloro complex dissociates with loss of a triphenylphosphine molecule, [See Thesis for equation] and in DMA solution, further dissociation of chloride ion from the bisphosphine complex occurs: [See Thesis for equation]. DMA solutions of RuCl₂(PPh₃)₃ react rapidly and reversibly with molecular hydrogen at room temperature, for example, [See Thesis for equation]. This hydrogenolysis reaction does not occur in benzene solution, but the basic amide solvent promotes hydride formation by effectively stabilizing the released HCl. The relative reactivity toward H₂ of the species present in solution is as follows: RuCl(PPh₃)₂⁺ > RuCl₂(PPh₃)₂ > RuCl₂(PPh₃)₃. For the reverse reaction between hydride complex and HCl, the reactivity order of species present is RuClH(PPh₃)₂ > RuClH(PPh₃)₃. Thermodynamic and kinetic data are given for equilibria such as (3), and thermodynamic data are presented for equilibria (1) and (2). The hydride complex RuClH(PPh₃)₃ is an extremely effective catalyst for the homogeneous hydrogenation of olefins in DMA solution at 35°. Unfavorable steric and electronic factors in the olefin both play a major role in reducing the rate of hydrogenation; these effects can be correlated with the proposed reaction mechanism, which involves a predissociation of the catalyst and the formation of a σ-alkyl intermediate via a hydrido-olefin species: [See Thesis for equation]. Equilibrium constants for reaction (5) with a variety of olefins, are presented together with rate data for reaction (6). Limited studies have been carried out using the corresponding hydridobromo and hydrido-acetate complexes. The hydride complex RuClH(PPh₃)₃ > isolated as a DMA solvate, is also effective as a catalyst for the polymerization of both ethylene and butadiene in DMA solution. The kinetics of these reactions have been studied and analyzed in terms of a mechanism that involves initial formation of a σ-alkyl complex, and propagation via insertion of coordinated olefin into the Ru-carbon bond, for example, [See Thesis for equation]. The ethylene and butadiene systems show different kinetic dependences which are accounted for by the stronger complexing of the diene.Science, Faculty ofChemistry, Department ofGraduat
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