126 research outputs found

    The Rascal meta-programming language - a lab for software analysis, transformation, generation & visualization

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    National audienceThis paper summarizes the goals and features of a do- main specific programming language called Rascal. On the one hand it is designed to facilitate software research -- research about software in general. On the other hand Rascal is applied to specific software portfolios as well, as a means to improve them and as a means to learn to understand them. Specifically, Rascal is used create tools that analyze, transform, generate or visualize source code of software products. Such tools are motivated by the need to im- prove quality of existing software or the need to lower its cost-of-ownership. More generally such tools are cre- ated to build laboratory experiments that observe and measure quality, or try and improve software quality, etc. In this paper we provide an overview of Rascal as a "domain specific language for meta programming". We first explain its goals and then its features. We end by highlighting some example applications in the area of software analysis and transformation

    Coarse-grained simulation of transmembrane peptides in the gel phase

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    We use Dissipative Particle Dynamics simulations, combined with parallel tempering and umbrella sampling, to investigate the potential of mean force between model transmembrane peptides in the various phases of a lipid bilayer, including the low-temperature gel phase. The observed oscillations in the effective interaction between peptides are consistent with the different structures of the surrounding lipid phases

    Assessment of the appropriateness of cardiovascular preventive medication in older people: using the RAND/UCLA Appropriateness Method

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    Background In clinical practice and science, there is debate for which older adults the benefits of cardiovascular preventive medications (CPM) still outweigh the risks in older age. Therefore, we aimed to assess how various clinical characteristics influence the judgement of appropriateness of CPM in older adults. Method We assessed the appropriateness of CPM for adults >= 75 years with regard to clinical characteristics (cardiovascular variables, complexity of health problems, age, side effects and life expectancy) using the RAND/ University of California at Los Angeles Appropriateness Method. A multidisciplinary panel, including 11 medical professionals and 3 older representatives of the target population, received an up-to-date overview of the literature. Using 9-point Likert scales (1 = extremely inappropriate; 9 = extremely appropriate), they assessed the appropriateness of starting and stopping cholesterol lowering medication, antihypertensives and platelet aggregation inhibitors, for various theoretical clinical scenarios. There were two rating rounds, with one face-to-face discussion in between. The overall appropriateness judgments were based on the median panel ratings of the second round and level of disagreement. Results The panelists emphasized the importance of the individual context of the patient for appropriateness of CPM. They judged that in general, a history of atherosclerotic cardiovascular disease strongly adds to the appropriateness of CPM, while increasing complexity of health problems, presence of hindering or severe side effects, and life expectancy Pathophysiology, epidemiology and therapy of agein

    Glycogenosis type II (acid maltase deficiency)

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    Glycogen storage disease type II (GSD II/glycogenosis type II/Pompe's disease/acid maltase deficiency) is caused by the deficiency of lysosomal α-glucosidase resulting in lysosomal accumulation of glycogen. The disease is inherited as an autosomal recessive trait and is clinically heterogeneous. Early and late onset phenotypes are distinguished. Insight in the molecular nature of the lysosomal α-glucosidase deficiency and the underlying genetic defect has increased significantly during the past decade. This minireview on GSD II was written at the occasion of The International Symposium on Glycolytic and Mitochondrial Defects in Muscle and Nerve, held in Osaka, Japan, July 1994. It is an update of current literature, but also includes original data from the collaborating authors on mutations occurring in the lysosomal α-glucosidase gene and on prenatal diagnosis by chorionic villus sampling. The genotype–phenotype correlation and the prospects for therapy are addressed

    High Sustained Antibody Titers in Patients with Classic Infantile Pompe Disease Following Immunomodulation at Start of Enzyme Replacement Therapy

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    Objective: To evaluate whether immunomodulation at start of enzyme replacement therapy induces immune tolerance to recombinant human acid alpha-glucosidase (rhGAA) in patients with classic infantile Pompe disease. Study design: Three patients (1 cross reactive immunologic material negative, 2 cross reactive immunologic material positive) were treated with 4 weekly doses of rituximab, weekly methotrexate, and monthly intravenous immunoglobulin and enzyme replacement therapy at 40 mg/kg/week. Antibody titers were measured using enzyme-linked immunosorbent assay. Neutralizing effects on rhGAA activity and cellular uptake were determined and combined with pharmacokinetic analysis. Clinical efficacy was evaluated by (ventilator-free) survival, reduction in left ventricular mass index, and improvement of motor function. Results: Immunomodulation induced B cell depletion that was accompanied by absence of antibody formation in all 3 patients. Upon cessation of rituximab treatment, all 3 patients showed B cell recovery, which was accompanied by formation of very high sustained antibody titers in 2 patients. Neutralizing effects on infused rhGAA were low to mild/moderate. All patients were alive at study end, learned to walk, and showed (near) normalization of left ventricular mass index. Conclusions: Immunomodulation as recommended in the literature prevented formation of rhGAA antibodies only during B cell depletion but failed to induce immune tolerance in 2 out of 3 patients

    Do we AGREE on the targets of antihypertensive drug treatment in older adults: a systematic review of guidelines on primary prevention of cardiovascular diseases

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    Abstract Background translation of the available evidence concerning primary cardiovascular prevention into clinical guidance for the heterogeneous population of older adults is challenging. With this review, we aimed to give an overview of the thresholds and targets of antihypertensive drug therapy for older adults in currently used guidelines on primary cardiovascular prevention. Secondly, we evaluated the relationship between the advised targets and guideline characteristics, including guideline quality. Methods we systematically searched PubMed, Embase, Emcare and five guideline databases. We selected guidelines with (i) numerical thresholds for the initiation or target values of antihypertensive drug therapy in context of primary prevention (January 2008–July 2020) and (ii) specific advice concerning antihypertensive drug therapy in older adults. We extracted the recommendations and appraised the quality of included guidelines with the AGREE II instrument. Results thirty-four guidelines provided recommendations concerning antihypertensive drug therapy in older adults. Twenty advised a higher target of systolic blood pressure (SBP) for octogenarians in comparison with the general population and three advised a lower target. Over half of the guidelines (n = 18) recommended to target a SBP <150 mmHg in the oldest old, while four endorsed targets of SBP lower than 130 or 120 mmHg. Although many guidelines acknowledged frailty, only three gave specific thresholds and targets. Guideline characteristics, including methodological quality, were not related with the recommended targets. Conclusion the ongoing debate concerning targets of antihypertensive treatment in older adults, is reflected in an inconsistency of recommendations across guidelines. Recommended targets are largely set on chronological rather than biological age.Public Health and primary careGeriatrics in primary car

    Generalized glycogen storage and cardiomegaly in a knockout mouse model of Pompe disease

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    Glycogen storage disease type II (GSDII; Pompe disease), caused by inherited deficiency of acid alpha-glucosidase, is a lysosomal disorder affecting heart and skeletal muscles. A mouse model of this disease was obtained by targeted disruption of the murine acid alpha-glucosidase gene (Gaa) in embryonic stem cells. Homozygous knockout mice (Gaa -/-) lack Gaa mRNA and have a virtually complete acid alpha-glucosidase deficiency. Glycogen-containing lysosomes are detected soon after birth in liver, heart and skeletal muscle cells. By 13 weeks of age, large focal deposits of glycogen have formed. Vacuolar spaces stain positive for acid phosphatase as a sign of lysosomal pathology. Both male and female knockout mice are fertile and can be intercrossed to produce progeny. The first born knockout mice are at present 9 months old. Overt clinical symptoms are still absent, but the heart is typically enlarged and the electrocardiogram is abnormal. The mouse model will help greatly to understand the pathogenic mechanism of GSDII and is a valuable instrument to explore the efficacy of different therapeutic interventions

    Mucopolysaccharidosis type VI phenotypes-genotypes and antibody response to galsulfase

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    Background: Mucopolysaccharidosis type VI (Maroteaux-Lamy syndrome; MPS VI) is an autosomal recessive lysosomal storage disorder in which deficiency of N-acetylgalactosamine 4-sulfatase (arylsulfatase B; ARSB) leads to the storage of glycosaminoglycans (GAGs) in connective tissue. The genotype-phenotype correlation has been addressed in several publications but the picture is not complete. Since 2007, enzyme-replacement therapy (ERT) has been available for patients with MPS VI in the Netherlands. The purpose of our study was to learn more about the genotype-phenotype correlations in MPS VI and the antibody response to ERT with galsulfase (recombinant human arylsulfatase B). Methods. We identified ARSB mutations in 12 patients and used site-directed mutagenesis to study their effect. Antibody levels to galsulfase were measured using ELISA and a semi-quantitative immunoprecipitation method. We assessed the in vitro inhibitory effect of antibodies on galsulfase uptake and their effect on clinical outcome. Results: Five patients had a rapidly progressive phenotype and seven a slowly progressive phenotype. In total 9 pathogenic mutations were identified including 4 novel mutations (N301K, V332G, A237D, and c.1142 + 2 T > C) together composing 8 pathogenic genotypes. Most mutations appeared not to affect the synthesis of ARSB (66 kD precursor), but to hamper its maturation (43 kD ARSB). Disease severity was correlated with urinary GAG excretion. All patients developed antibodies to galsulfase within 26 weeks of treatment. It was demonstrated that these antibodies can inhibit the uptake of galsulfase in vitro. Conclusions: The clinical phenotypes and the observed defects in the biosynthesis of ARSB show that some of the mutations that we identified are clearly more severe than others. Patients receiving galsulfase as enzyme-replacement therapy can develop antibodies towards the therapeutic protein. Though most titers are modest, they can exceed a level at which they potentially affect the clinical outcome of enzyme-replacement therapy
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