160 research outputs found

    A Model of Methotrexate Encephalopathy: Neurotransmitter and Pathologic Abnormalities

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    Methotrexate may cause seizures, dementia, and leukoencephalopathy when given in toxic doses to children with leukemia or solid tumors. Even in therapeutic doses, treatment with this drug is associated with an increased incidence of seizures in children with leukemia. To study mechanisms of injury, juvenile rats were given multiple intraventricular injections of methotrexate and the brains were analyzed for histopathology and biogenic amine metabolites of dopamine and serotonin. Disruption of monoamine metabolism has been proposed as a cause of brain dysfunction from this chemotherapy. Multiple injections (1 or 2 mg/kg) produced convulsions in an increasingly larger percentage of animals at higher cumulative doses, and five doses produced the neuropathological changes seen in human leukoencephalopathy. A single dose reduced the concentration of brain metabolites of dopamine, but not serotonin, six hours later. The effect was less pronounced after five doses. This rodent model should be useful for studying the metabolic basis of methotrexate encephalopathy. (J Child Neurol 1986;1:351-357)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67332/2/10.1177_088307388600100406.pd

    3D Scene Reconstruction by Stereo Methods for Analysis and Visualization of Sports Scenes

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    The 3D reconstruction of image and video scenes by stereo analysis is an important topic in computer vision research. In this talk, we first present some principles of stereo algorithms and recent developments. We then demonstrate two applications of stereo reconstruction for the analysis and visualization of human movement: (a) We employ depth maps derived from sport scenes for novel view synthesis, and (b) we show how stereo processing can be used for expressive visualization of human motion in a comic-like style

    Renal insufficiency as a predictor of cardiovascular outcomes and mortality in elderly individuals

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    AbstractObjectivesThis study was designed to evaluate the relationship between elevated creatinine levels and cardiovascular events.BackgroundEnd-stage renal disease is associated with high cardiovascular morbidity and mortality. The association of mild to moderate renal insufficiency with cardiovascular outcomes remains unclear.MethodsWe analyzed data from the Cardiovascular Health Study, a prospective population-based study of subjects, aged >65 years, who had a serum creatinine measured at baseline (n = 5,808) and were followed for a median of 7.3 years. Proportional hazards models were used to examine the association of creatinine to all-cause mortality and incident cardiovascular mortality and morbidity. Renal insufficiency was defined as a creatinine level ≥1.5 mg/dl in men or ≥1.3 mg/dl in women.ResultsAn elevated creatinine level was present in 648 (11.2%) participants. Subjects with elevated creatinine had higher overall (76.7 vs. 29.5/1,000 years, p < 0.001) and cardiovascular (35.8 vs. 13.0/1,000 years, p < 0.001) mortality than those with normal creatinine levels. They were more likely to develop cardiovascular disease (54.0 vs. 31.8/1,000 years, p < 0.001), stroke (21.1 vs. 11.9/1,000 years, p < 0.001), congestive heart failure (38.7 vs. 17/1,000 years, p < 0.001), and symptomatic peripheral vascular disease (10.6 vs. 3.5/1,000 years, p < 0.001). After adjusting for cardiovascular risk factors and subclinical disease measures, elevated creatinine remained a significant predictor of all-cause and cardiovascular mortality, total cardiovascular disease (CVD), claudication, and congestive heart failure (CHF). A linear increase in risk was observed with increasing creatinine.ConclusionsElevated creatinine levels are common in older adults and are associated with increased risk of mortality, CVD, and CHF. The increased risk is apparent early in renal disease

    Determinants of completion of advance directives: a cross-sectional comparison of 649 outpatients from private practices versus 2158 outpatients from a university clinic

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    Objectives To compare outpatients from private practices and outpatients from a university clinic regarding the determinants of completion of advance directives (AD) in order to generalise results of studies from one setting to the other. Five determinants of completion of AD were studied: familiarity with AD, source of information about AD, prior experiences with own life-threatening diseases or family members in need of care and motives in favour and against completion of AD.Design Observational cross-sectional study.Setting Private practices and a university clinic in Germany in 2012.Participants 649 outpatients from private practices and 2158 outpatients from 10 departments of a university clinic.Outcome measures Completion of AD, familiarity with AD, sources of information about AD (consultation), prior experiences (with own life-threatening disease and family members in need of care), motives in favour of or against completion of AD, sociodemographic data.Results Determinants of completion of AD did not differ between outpatients from private practices versus university clinic outpatients. Prior experience with severe disease led to a significantly higher rate of completion of AD (33%/36% with vs 24%/24% without prior experience). Participants with completion of AD had more often received legal than medical consultation before completion, but participants without completion of AD are rather aiming for medical consultation. The motives in favour of or against completion of AD indicated inconsistent patterns.Conclusions Determinants of completion of AD are comparable in outpatients from private practices and outpatients from a university clinic. Generalisations from university clinic samples towards a broader context thus seem to be legitimate. Only one-third of patients with prior experience with own life-threatening diseases or family members in need of care had completed an AD as expression of their autonomous volition. The participants’ motives for or against completion of AD indicate that ADs are considered a kind of ‘negative autonomy’ as instruments to prevent particular forms of therapy. Interactive, repeated and situation-based AD discussions might reach a higher percentage of patients and concurrently enable personal volitions and thereby strengthen individual ‘positive autonomy’.</p

    Coloration in supraparticles assembled from polyhedral metal-organic framework particles

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    Supraparticles are spherical colloidal crystals prepared by confined self-assembly processes. A particularly appealing property of these microscale structures is the structural color arising from interference of light with their building blocks. Here, we assemble supraparticles with high structural order that exhibit coloration from uniform, polyhedral metal-organic framework (MOF) particles. We analyse the structural coloration as a function of the size of these anisotropic building blocks and their internal structure. We attribute the angle-dependent coloration of the MOF supraparticles to the presence of ordered, onion-like layers at the outermost regions. Surprisingly, even though different shapes of the MOF particles have different propensities to form these onion layers, all supraparticle dispersions show well-visible macroscopic coloration, indicating that local ordering is sufficient to generate interference effects

    Clinical characterization of a family with a mutation in the uromodulin (Tamm-Horsfall glycoprotein) gene

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    Clinical characterization of a family with a mutation in the uromodulin (Tamm-Horsfall glycoprotein) gene.BackgroundWe have recently identified a mutation in the uromodulin gene in a large family affected with hyperuricemia, gout, and renal failure. The purpose of this investigation is to provide a comprehensive characterization of the clinical findings of this syndrome in family members who had a mutation in the uromodulin gene.MethodsAn extended family suffering from hyperuricemia and gout was identified by a local practitioner. After consent was obtained, patients provided a directed clinical history and blood and urine specimens for chemical and genetic testing. All family members were tested for the presence of uromodulin gene mutations by direct DNA sequence analysis. The clinical and biochemical characteristics of family members carrying the affected mutation were then investigated.ResultsThirty-nine family members were found to have an exon 5 uromodulin gene mutation (g.1966 1922 del), and 29 unaffected family members were identified. The cardinal clinical features in individuals with the uromodulin mutation included hyperuricemia, decreased fractional excretion of uric acid, and chronic interstitial renal disease leading to end-stage renal disease (ESRD) in the fifth through seventh decade. Women did not always develop hyperuricemia or gout, but still developed progressive chronic renal failure.ConclusionMutation of the uromodulin gene resulted in hyperuricemia, reduced fractional excretion of uric acid, and renal failure. Genetic testing will be required to definitively identify individuals suffering from this condition. We are interested in studying other families that may suffer from this condition and would appreciate any such referrals

    Period-doubling bifurcation in strongly anisotropic Bianchi I quantum cosmology

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    We solve the Wheeler-DeWitt equation for the minisuperspace of a cosmological model of Bianchi type I with a minimally coupled massive scalar field ϕ\phi as source by generalizing the calculation of Lukash and Schmidt [1]. Contrarily to other approaches we allow strong anisotropy. Combining analytical and numerical methods, we apply an adiabatic approximation for ϕ\phi, and as new feature we find a period-doubling bifurcation. This bifurcation takes place near the cosmological quantum boundary, i.e., the boundary of the quasiclassical region with oscillating ψ\psi-function where the WKB-approximation is good. The numerical calculations suggest that such a notion of a ``cosmological quantum boundary'' is well-defined, because sharply beyond that boundary, the WKB-approximation is no more applicable at all. This result confirms the adequateness of the introduction of a cosmological quantum boundary in quantum cosmology.Comment: Latest update of the paper at http://www.physik.fu-berlin.de/~mbach/publics.html#

    Uromodulin concentrations are not associated with incident CKD among persons with coronary artery disease

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    <p>Abstract</p> <p>Background</p> <p>A common variant of the UMOD gene was linked with prevalent chronic kidney disease (CKD) in large, genomics consortia. One community-based study found that urine concentrations of the uromodulin protein forecast risk of incident CKD. This study within persons with known coronary artery disease (CAD) evaluated whether uromodulin concentrations could distinguish CKD risk.</p> <p>Methods</p> <p>In the Heart and Soul Study, the UMOD snp (12917707) was genotyped in 879 individuals with baseline creatinine clearance (CrCl) measured from a 24-hour urine collection. Uromodulin protein was measured from stored urine specimens among a subset of 120 participants, balanced by genotype. Incident CKD cases (N = 102) were defined by an initial CrCl > 70 ml/min and a 5-year follow-up CrCl <60 ml/min; controls (N = 94) were matched on age, sex, and race.</p> <p>Results</p> <p>Among 527 self-described White participants with DNA, 373 (71%) were homozygous for the dominant allele (G/G), 133 (25%) were heterozygous (G/T) and only 21 (4%) were homozygous for the minor allele (T/T). The T/T genotype had an approximately 11 ml/min higher CrCl than the other 2 groups, but this difference did not reach statistical significance (p = 0.20). The T/T genotype had significantly lower uromodulin levels than the common G/G genotype, and the G/T genotype had intermediate levels. However, uromodulin concentrations were similar between cases and controls (44 vs. 48 mg/dL, p = 0.88).</p> <p>Conclusions</p> <p>This study among a cohort of persons with established CAD found no association between urine uromodulin and incident CKD, although UMOD genotype was associated with urine uromodulin concentrations.</p

    Anti-TNF drives regulatory T cell expansion by paradoxically promoting membrane TNF-TNF-RII binding in rheumatoid arthritis

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    The interplay between inflammatory and regulatory pathways orchestrates an effective immune response that provides protection from pathogens while limiting injury to host tissue. Tumor necrosis factor (TNF) is a pivotal inflammatory cytokine, but there is conflicting evidence as to whether it boosts or inhibits regulatory T cells (T reg cells). In this study, we show that the therapeutic anti-TNF antibody adalimumab, but not the soluble TNF receptor etanercept, paradoxically promoted the interaction between monocytes and T reg cells isolated from patients with rheumatoid arthritis (RA). Adalimumab bound to monocyte membrane TNF from RA patients and unexpectedly enhanced its expression and its binding to TNF-RII expressed on T reg cells. As a consequence, adalimumab expanded functional Foxp3(+) T reg cells equipped to suppress Th17 cells through an IL-2/STAT5-dependent mechanism. Our data not only highlight the beneficial effect of membrane TNF on T reg cell numbers during chronic inflammation, but in addition reveal how a therapeutic antibody that is thought to act by simply blocking its target can enhance the regulatory properties of this proinflammatory cytokine

    An intermediate-effect size variant in UMOD confers risk for chronic kidney disease

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    The kidney-specific gene UMOD encodes for uromodulin, the most abundant protein excreted in normal urine. Rare large-effect variants in UMOD cause autosomal dominant tubulointerstitial kidney disease (ADTKD), while common low-impact variants strongly associate with kidney function and the risk of chronic kidney disease (CKD) in the general population. It is unknown whether intermediate-effect variants in UMOD contribute to CKD. Here, candidate intermediate-effect UMOD variants were identified using large-population and ADTKD cohorts. Biological and phenotypical effects were investigated using cell models, in silico simulations, patient samples, and international databases and biobanks. Eight UMOD missense variants reported in ADTKD are present in the Genome Aggregation Database (gnomAD), with minor allele frequency (MAF) ranging from 10(−5) to 10(−3). Among them, the missense variant p.Thr62Pro is detected in ∼1/1,000 individuals of European ancestry, shows incomplete penetrance but a high genetic load in familial clusters of CKD, and is associated with kidney failure in the 100,000 Genomes Project (odds ratio [OR] = 3.99 [1.84 to 8.98]) and the UK Biobank (OR = 4.12 [1.32 to 12.85). Compared with canonical ADTKD mutations, the p.Thr62Pro carriers displayed reduced disease severity, with slower progression of CKD and an intermediate reduction of urinary uromodulin levels, in line with an intermediate trafficking defect in vitro and modest induction of endoplasmic reticulum (ER) stress. Identification of an intermediate-effect UMOD variant completes the spectrum of UMOD-associated kidney diseases and provides insights into the mechanisms of ADTKD and the genetic architecture of CKD
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