256 research outputs found
Analytical method for the determination of trichlorobenzenes in marine biota (poster)
Trichlorobenzenes (TCBs) were intensively used in the last decades as essential components of dielectric fluids, intermediates in chemical synthesis, solvents, coolants, lubricants, heat-transfer medium; insecticide, additive in polyester dyeing and components of termite-control preparations (1, 2). Due to their widespread occurrence in the various environmental compartments they have been classified by OSPARCOM (Oslo and Paris Commissions) (3) as chemicals for priority action and have been proposed by the Marine Chemistry Working Group (MCWG) as chemical parameters in the Water Framework Directive (4). Based on their octanol-water partitioning coefficients (log Kow = 4.02-4.49) (5) and bioconcentration factors in fish (ranging from 182 to 3200, depending on the lipid content) (6), these chemicals are expected to bioaccumulate in aquatic organisms.Against their potential significance in the marine environment there is relatively little information available concerning the actual concentration levels and distribution of trichlorobenzenes in marine organisms (7, 8).The aim of this work was to develop an analytical method appropriate for the determination of TCBs in marine biota.The analytical method consists of saponification of the fish tissue with methanolic potassium hydroxide, liquid-liquid extraction of the solution with pentane, clean up of the concentrated extract on alumina column and analysis of the extract with gas chromatograph equipped with electron capture detector (ECD). The method proved to be appropriate for the detection of concentration levels typical of the organic contaminants in biota (7) (~1 ng /g wet weight of tissue). The relative standard deviation of the analysis of 1,3,5-, 1,2,4- and 1,2,3-trichlorobenzene was 8, 6 and 18% (n=4) respectively. Higher recoveries of the analytes were obtained with spiked fish samples than with standard solutions (88, 96 and 78 instead of 53, 50 and 32% of 1,3,5-, 1,2,4- and 1,2,3-trichlorobenzene respectively). One plausible explanation of the difference is that the proteins and glycerides of the fish tissue compete effectively with trichlorobenzenes for the base and their presence decrease their decomposition rate
Coronary flow velocity reserve after percutaneous interventions is predictive of periprocedural outcome
BACKGROUND: Because heterogeneous results have been reported, we assessed coronary flow velocity changes in individuals who underwent percutaneous transluminal coronary angioplasty (PTCA) and examined their impact on clinical outcome. METHODS AND RESULTS: As part of the Doppler Endpoints Balloon Angioplasty Trial Europe (DEBATE) II study, 379 patients underwent Doppler flow-guided angioplasty. All patients were evaluated according to their coronary flow velocity reserve (CFVR) results (> or =2.5 or < 2.5) at the end of the procedure. A CFVR < 2.5 after angioplasty was associated with an elevated baseline blood flow velocity in both the target artery and reference artery. CFVR before PTCA and CFVR in the reference artery were independent predictors of an optimal CFVR after balloon angioplasty (CFVR before PTCA: odds ratio [OR], 2.26; 95% confidence interval [CI], 1.57 to 3.24; CFVR in reference artery: OR, 1.90; 95% CI, 1.21 to 2.98; both P<0.001) and stent implantation (before PTCA: OR, 2.54; 95% CI, 1.47 to 4.36; reference artery: OR, 1.97; 95% CI, 1.07 to 3.87; both P<0.05). A low CFVR at the end of the procedure was an independent p
Uncomplicated moderate coronary artery dissections after balloon angioplasty: good outcome without stenting
OBJECTIVE: To study the relation between moderate coronary dissections, coronary flow velocity reserve (CFVR), and long term outcome. METHODS: 523 patients undergoing balloon angioplasty and sequential intracoronary Doppler measurements were examined as part of the DEBATE II trial (Doppler endpoints balloon angioplasty trial Europe). After successful balloon angioplasty, patients were randomised to stenting or no further treatment. Dissections were graded at the core laboratory by two observers and divided into four categories: none, mild (type A-B), moderate (type C), severe (types D to F). Patients with severe dissections (n = 128) or without available reference vessel CFVR (n = 139) were excluded. The remaining 256 patients were divided into two groups according to the presence (group A, n = 45) or absence (group B, n = 211) of moderate dissection. RESULTS: Following balloon angioplasty, there was no difference in CFVR between the two groups. At 12 months follow up, a higher rate of major adverse cardiac events was observed overall in group A than in group B (10 (22%) v 23 (11%), p = 0.041). However, the risk of major adverse events was similar in the subgroups receiving balloon angioplasty (group A, 6 (19%) v group B, 16 (16%), NS). Among group A patients, the adverse events risk was greater in those randomised to stenting (odds ratios 6.603 v 1.197, p = 0.046), whereas there was no difference in risk if the group was analysed according to whether the CFVR was /= 2.5 after balloon angioplasty. CONCLUSIONS: Moderate dissections left untreated result in no increased risk of major adverse cardiac events. Additional stenting does not improve the long term outcome
Regional actorness and interregional relations:ASEAN, the EU and Mercosur
The European Union (EU) has a long tradition of interregional dialogue mechanisms with other regional organisations and is using these relations to project its own model of institutionalised actorness. This is partly motivated by the emerging actorness of the EU itself, which benefits from fostering capable regional counterparts in other parts of the world. This article advances the argument that actorness, which we conceptualise in terms of institutions, recognition and identity, is a relational concept, dependent on context and perception. Taking the Association of Southeast Asian Nations (ASEAN) and the Common Market of the South (Mercosur) and their relations with the EU as case studies, this article demonstrates that the actorness capabilities of all three organisations have been enhanced as result of ASEAN-EU and Mercosur-EU relations. However, there are clear limits to the development of the three components of regional actorness and to the interregional relations themselves. These limits stem both from the type of interregionalism at play and from the different regional models the actors incorporate. While there is evidence of institutional enhancement in ASEAN and Mercosur, these formal changes have been grafted on top of firmly entrenched normative underpinnings. Within the regional organisations, interactions with the EU generate centrifugal forces concerning the model to pursue, thus limiting their institutional cohesion and capacity. In addition, group-to-group relations have reinforced ASEAN and Mercosur identities in contrast to the EU. The formation of such differences has narrowed the scope of EU interregionalism despite the initial success of improved regional actorness
FUS Transgenic Rats Develop the Phenotypes of Amyotrophic Lateral Sclerosis and Frontotemporal Lobar Degeneration
Fused in Sarcoma (FUS) proteinopathy is a feature of frontotemporal lobar dementia (FTLD), and mutation of the fus gene segregates with FTLD and amyotrophic lateral sclerosis (ALS). To study the consequences of mutation in the fus gene, we created transgenic rats expressing the human fus gene with or without mutation. Overexpression of a mutant (R521C substitution), but not normal, human FUS induced progressive paralysis resembling ALS. Mutant FUS transgenic rats developed progressive paralysis secondary to degeneration of motor axons and displayed a substantial loss of neurons in the cortex and hippocampus. This neuronal loss was accompanied by ubiquitin aggregation and glial reaction. While transgenic rats that overexpressed the wild-type human FUS were asymptomatic at young ages, they showed a deficit in spatial learning and memory and a significant loss of cortical and hippocampal neurons at advanced ages. These results suggest that mutant FUS is more toxic to neurons than normal FUS and that increased expression of normal FUS is sufficient to induce neuron death. Our FUS transgenic rats reproduced some phenotypes of ALS and FTLD and will provide a useful model for mechanistic studies of FUS–related diseases
Distinct tau prion strains propagate in cells and mice and define different tauopathies
Prion-like propagation of tau aggregation might underlie the stereotyped progression of neurodegenerative tauopathies. True prions stably maintain unique conformations (“strains”) in vivo that link structure to patterns of pathology. We now find that tau meets this criterion. Stably expressed tau repeat domain indefinitely propagates distinct amyloid conformations in a clonal fashion in culture. Reintroduction of tau from these lines into naive cells reestablishes identical clones. We produced two strains in vitro that induce distinct pathologies in vivo as determined by successive inoculations into three generations of transgenic mice. Immunopurified tau from these mice recreates the original strains in culture. We used the cell system to isolate tau strains from 29 patients with 5 different tauopathies, finding that different diseases are associated with different sets of strains. Tau thus demonstrates essential characteristics of a prion. This might explain the phenotypic diversity of tauopathies and could enable more effective diagnosis and therapy
The genetics and neuropathology of frontotemporal lobar degeneration
Frontotemporal lobar degeneration (FTLD) is a heterogeneous group of disorders characterized by disturbances of behavior and personality and different types of language impairment with or without concomitant features of motor neuron disease or parkinsonism. FTLD is characterized by atrophy of the frontal and anterior temporal brain lobes. Detailed neuropathological studies have elicited proteinopathies defined by inclusions of hyperphosphorylated microtubule-associated protein tau, TAR DNA-binding protein TDP-43, fused-in-sarcoma or yet unidentified proteins in affected brain regions. Rather than the type of proteinopathy, the site of neurodegeneration correlates relatively well with the clinical presentation of FTLD. Molecular genetic studies identified five disease genes, of which the gene encoding the tau protein (MAPT), the growth factor precursor gene granulin (GRN), and C9orf72 with unknown function are most frequently mutated. Rare mutations were also identified in the genes encoding valosin-containing protein (VCP) and charged multivesicular body protein 2B (CHMP2B). These genes are good markers to distinguish underlying neuropathological phenotypes. Due to the complex landscape of FTLD diseases, combined characterization of clinical, imaging, biological and genetic biomarkers is essential to establish a detailed diagnosis. Although major progress has been made in FTLD research in recent years, further studies are needed to completely map out and correlate the clinical, pathological and genetic entities, and to understand the underlying disease mechanisms. In this review, we summarize the current state of the rapidly progressing field of genetic, neuropathological and clinical research of this intriguing condition
FUS and TARDBP but Not SOD1 Interact in Genetic Models of Amyotrophic Lateral Sclerosis
Mutations in the SOD1 and TARDBP genes have been commonly identified in Amyotrophic Lateral Sclerosis (ALS). Recently, mutations in the Fused in sarcoma gene (FUS) were identified in familial (FALS) ALS cases and sporadic (SALS) patients. Similarly to TDP-43 (coded by TARDBP gene), FUS is an RNA binding protein. Using the zebrafish (Danio rerio), we examined the consequences of expressing human wild-type (WT) FUS and three ALS–related mutations, as well as their interactions with TARDBP and SOD1. Knockdown of zebrafish Fus yielded a motor phenotype that could be rescued upon co-expression of wild-type human FUS. In contrast, the two most frequent ALS–related FUS mutations, R521H and R521C, unlike S57Δ, failed to rescue the knockdown phenotype, indicating loss of function. The R521H mutation caused a toxic gain of function when expressed alone, similar to the phenotype observed upon knockdown of zebrafish Fus. This phenotype was not aggravated by co-expression of both mutant human TARDBP (G348C) and FUS (R521H) or by knockdown of both zebrafish Tardbp and Fus, consistent with a common pathogenic mechanism. We also observed that WT FUS rescued the Tardbp knockdown phenotype, but not vice versa, suggesting that TARDBP acts upstream of FUS in this pathway. In addition we observed that WT SOD1 failed to rescue the phenotype observed upon overexpression of mutant TARDBP or FUS or upon knockdown of Tardbp or Fus; similarly, WT TARDBP or FUS also failed to rescue the phenotype induced by mutant SOD1 (G93A). Finally, overexpression of mutant SOD1 exacerbated the motor phenotype caused by overexpression of mutant FUS. Together our results indicate that TARDBP and FUS act in a pathogenic pathway that is independent of SOD1
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