1,721,304 research outputs found
Spielmeyer-Vogts sjukdom - dess fortskridande tunga handikapp- problematik
Full text linkSpielmeyer-Vogts sjukdom är en fortskridande, recessivt ärftlig hjärnsjukdom som i Sverige förekommer hos 5 per miljon invånare. Drygt 40 personer med sjukdomen är kända. lncidensen är 3 per 100 000 födda. Sjukdomen debuterar strax före skolåldern med synnedsättning ledande till blindhet, följt av mental tillbakagång, förlust av talförmåga, epilepsi och störd rörelseförmåga. Flertalet avlider mellan 20 och 30 års ålder.För att belysa den psykosociala situationen för dessa personer och deras familjer utformades en enkät som besvarades av vårdnadshavare till 21 ungdomar och unga vuxna. De funktionshinder som upplevdes som mest belastande var kommunikationssvårigheter (förlusten av talförmågan), följt av rörelsehinder och epilepsi. Som svårast för familjen angavs "att aldrig känna sig fri", samt att inte få uppleva ostörd sömn. Socialt betungande var brist på fritidsaktiviteter, sjukhusvistelser samt sökandet efter praktisk hjälp och samordningen av insatser runt den sjuke.Synpunkter på pedagogiskt, praktiskt, socialt och psykologiskt stöd ges av Spielmeyer- Vogt konsulenter med lång erfarenhet av sjukdome
Faster ciguatoxin extraction methods for toxicity screening
No full textAbstract Ciguatera poisoning (CP) is a severe global public health problem caused by the consumption of seafood products contaminated with ciguatoxins (CTXs). The growing demand for seafood products requires high-throughput testing for CTX-susceptible seafood, however complex extraction and slow cleanup methods inhibit this goal. Herein, several methods for extracting CTXs from fish tissue were established and compared; these methods are sensitive, specific, and valid while achieving higher sample extraction throughput than currently established protocols. The trial fish material was generated from multiple species, with different physical conditions (wet and freeze-dried tissue), and naturally contaminated with various CTXs (i.e., CTX-1B, CTX-3C, and C-CTX-1), thus ensuring these methods are robust and broadly applicable. The extraction methods used were based on mechanical maceration with acetone or methanol or enzymatic digestion followed by acetone and ethyl acetate extraction. Crude extracts were investigated for CTX-like toxicity using an in vitro mouse neuroblastoma (N2a) cell-based assay (CBA). Among the three methods, there was no significant difference in toxin estimates (p = 0.219, two-way ANOVA), indicating their interchangeability. For speed (> 16 samples/day), accuracy (100%), and CTX analog retention confirmation by liquid chromatography-tandem mass spectrometry (LC‒MS/MS), the preferred extraction methods were both methanol and enzyme-based. All extraction methods post hoc confirmation of CTX analogs successfully met international seafood market-based CTX contaminant guidance. These methods can drastically increase global CTX screening capabilities and subsequently relieve sample processing bottlenecks, inhibiting environmental and human health-based CTX analysis
Fish Extract Fractionation by Solid Phase Extraction: Investigating Co-Occurring Ciguatoxins by LC-MS/MS and N2a-Bioassay
No full textCiguatoxins (CTXs) are neurotoxic marine biotoxins capable of contaminating marine organisms. Approximately 30 CTX analogues have been described; however, only a few have been documented in ciguatera poisoning (CP) outbreaks. Detecting CTXs from complex matrices at CP-relevant concentrations (<1 µg per kg seafood tissue) is analytically challenging. Analytical standards for CTXs are rare. Even after multi-step sample preparation (including liquid–liquid partition, defatting, and solid-phase extraction (SPE)), extracts can contain undesirable co-eluting matrix components. These limitations can exacerbate discrepancies between results obtained by LC-MS/MS and the N2a-bioassay, which are two common CTX detection methods. Herein, a rapid and simple fractionation method, based on normal phase SPE (silica), is demonstrated. Target CTXs were eluted using solvent mixtures of ascending polarity, passed through the column, and separated into eight fractions. To challenge the method, extracts with eleven naturally incurred CTX analogues among different structural CTX groups (e.g., CTX3C, CTX4A, and C-CTX group) were used. The most complex tissue matrix tested (viscera) was improved the most for extract purity and CTX detection, enhancing the correlation between LC-MS/MS and N2a-bioassay results. This workflow represents an advancement for characterizing CTXs in seafood products and CP outbreaks, irrespective of the responsible CTX analogue and where standards are lacking
Identical Ciguatoxin-3C group profiles in Lutjanus bohar from the Pacific and Indian Oceans - indicating the need to re-evaluate geographical CTX classifications
No full textCiguatoxins (CTXs) are a group of marine biotoxins, consisting of over 30 different congeners that can contaminate marine food webs. Generally, the molecular structures among the known congeners are variable by geographical region (i.e., ocean basin) and vector species. Limited information is available regarding the CTX profiles among or within CTX vector species and their capture regions. Within this study, an in-depth investigation based on a semi-targeted LC-MS/MS approach was conducted to investigate 52 tissue samples from a single species Lutjanus bohar (Lutjanidae), a common CTX vector, sourced from two distinct regions (Indian Ocean and Pacific Ocean). All samples revealed the presence of a complex CTX contaminant profile, with samples containing several congeners of the CTX3C-group (2,3,51-trihydroxyCTX3C, 2,3,-dihydroxyCTX3C, 2-hydroxyCTX3C, M-seco-CTX3C, 51-hydroxyCTX3C, CTX3C, and respective 49-epimers in most cases). All samples were previously found to possess a CTX-like toxicity within an in vitro cytotoxicity assay (N2a-bioassay), demonstrating the relevance of CTX3C-group congeners with regard to ciguatera poisoning. Individual samples contained an indistinguishable toxin profile within the species and among the distinct oceanic capture regions. These findings imply either a species-specific CTX metabolism or the emergence of an interoceanic CTX toxin profile. The inter-regional CTX profile demonstrated here provides further evidence that classifying CTX congeners based on ocean basins may be imprecise.</jats:p
Lipoyl dehydrogenase activity of erythrocytes in Spielmeyer-Vogt-Batten's disease
No full textUsing the method for the determination of the lipoyl dehydrogenase activity in intact erythrocytes described by Seet and Lee (1975), it was demonstrated that in patients with Spielmeyer-Vogt-Batten's disease, this activity was around the lower limit of normal. In these patients, the enzymatic activity is significantly reduced to such an extent that it may affect the function and metabolism of the erythrocytes.</p
Lipoyl dehydrogenase activity of erythrocytes in Spielmeyer-Vogt-Batten's disease
No full textUsing the method for the determination of the lipoyl dehydrogenase activity in intact erythrocytes described by Seet and Lee (1975), it was demonstrated that in patients with Spielmeyer-Vogt-Batten's disease, this activity was around the lower limit of normal. In these patients, the enzymatic activity is significantly reduced to such an extent that it may affect the function and metabolism of the erythrocytes.</p
Extraction and LC-MS/MS Analysis of Ciguatoxins: A Semi-Targeted Approach Designed for Fish of Unknown Origin
No full textCiguatoxins (CTXs) are polyether marine biotoxins that can cause ciguatera poisoning (CP) after the consumption of fish or invertebrates containing sub ppb levels; concentrations that present a challenge for current extraction and analysis methods. Here, a newly developed and (partly) validated single-day extraction protocol is presented. First, the fish sample is broken-down by enzymatic digestion, followed by extraction and extract clean-up by defatting and two solid-phase extractions. Final extracts were investigated using two different CTX-analysis methods; an in vitro cytotoxicity assay (N2a-assay) and by LC-MS/MS. Validation was performed for both fillet and freeze-dried samples of snapper, parrotfish, and grouper spiked with CTX1B, 52-epi-54-deoxyCTX1B, 54-deoxyCTX1B, and CTX3C. Based on recovery rates (35–88%) and matrix effects (66–116%) determined by LC-MS/MS, the enzyme protocol is applicable to various matrices. The protocol was applied to naturally contaminated fish tissue (Lutjanus bohar) obtained during a CP incident in Germany. Several potential CTX congeners were identified by a two-tier LC-MS/MS approach (screening of sodium adducts, high-resolution or low-resolution confirmation via ammonium adducts). Inclusion of >30 known CTX congeners into the LC-MS/MS methods and single-day sample preparation make the method suitable for analysis of ciguatera suspect samples at sub ppb levels also with undisclosed CTX profiles
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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