Where and when to inject low molecular weight heparin in hemodiafiltration? : a cross over randomised trial

Background and Objective : Low molecular weight heparins (LMWHs) are small enough to pass large pore dialysis membranes. Removal of LMWH if injected before the start of the session is possible during high-flux dialysis and hemodiafiltration. The aim of this study was to determine the optimal mode (place and time) of tinzaparin administration during postdilution hemodiafiltration. Study Design, Setting, Patients : In 13 chronic hemodiafiltration patients, 3 approaches of injection were compared in a randomised cross over trial: i) before the start of the session at the inlet blood line filled with rinsing solution (IN0), ii) 5 min after the start at the inlet line filled with blood (IN5) and iii) before the start of the session at the outlet blood line (OUT0). Anti-Xa activity, thrombin generation, visual clotting score and reduction ratios of urea and beta2microglobulin were measured. Results : Anti-Xa activity was lower with IN0 compared with IN5 and OUT0, and also more thrombin generation was observed with IN0. No differences were observed in visual clotting scores and no clinically relevant differences were observed in solute reduction ratio. An anti-Xa of 0.3 IU/mL was discriminative for thrombin generation. Anti-Xa levels below 0.3 IU/mL at the end of the session were associated with worse clotting scores and lower reduction ratio of urea and beta2microglobulin. Conclusions : Injection of tinzaparin at the inlet line before the start of postdilution hemodiafiltration is associated with loss of anticoagulant activity and can therefore not be recommended. Additionally, we found that an anti-Xa above 0.3 IU/mL at the end of the session is associated with less clotting and higher dialysis adequacy

Magnetic resonance imaging for forensic age estimation in living children and young adults : a systematic review

Background The use of magnetic resonance imaging (MRI) in forensic age estimation has been explored extensively during the past decade. Objective To synthesize the available MRI data for forensic age estimation in living children and young adults, and to provide a comprehensive overview that can guide age estimation practice and future research. Materials and Methods MEDLINE, Embase and Web of Science were searched. Additionally, cited and citing articles and study registers were searched. Two authors independently selected articles, conducted data extraction, and assessed risk of bias. Study populations including living subjects up to 30 years were considered. Results Fifty-five studies were included in qualitative analysis and 33 in quantitative analysis. Most studies suffered from bias, including relatively small European (Caucasian) populations, varying MR-approaches and varying staging techniques. Therefore, pooling of the age distribution data was not appropriate. Reproducibility of staging was remarkably lower in clavicles than in any other anatomical structure. Age estimation performance was in line with the gold standard, which uses radiographs, with mean absolute errors ranging from 0.85 to 2.0 years. The proportion of correctly classified minors ranged from 65% to 91%. Multi-factorial age estimation performed better than based on a single anatomical site. Conclusion More multi-factorial age estimation studies are necessary, together with studies testing if the MRI data can safely be pooled. The current review results can guide future studies, help medical professionals to decide on the preferred approach for specific cases, and help judicial professionals to interpret the evidential value of age estimation results

Efficient CRISPR-mediated base editing in Agrobacterium spp.

Agrobacterium spp. are important plant pathogens that are the causative agents of crown gall or hairy root disease. Their unique infection strategy depends on the delivery of part of their DNA to plant cells. Thanks to this capacity, these phytopathogens became a powerful and indispensable tool for plant genetic engineering and agricultural biotechnology. Although Agrobacterium spp. are standard tools for plant molecular biologists, current laboratory strains have remained unchanged for decades and functional gene analysis of Agrobacterium has been hampered by time-consuming mutation strategies. Here, we developed clustered regularly inter-spaced short palindromic repeats (CRISPR)-mediated base editing to enable the efficient introduction of targeted point mutations into the genomes of both Agrobacterium tumefaciens and Agro-bacterium rhizogenes. As an example, we generated EHA105 strains with loss-of-function mutations in recA, which were fully functional for maize (Zea mays) transformation and confirmed the importance of RolB and RolC for hairy root development by A. rhizogenes K599. Our method is highly effective in 9 of 10 colonies after transformation, with edits in at least 80% of the cells. The genomes of EHA105 and K599 were resequenced, and genome-wide off-target analysis was applied to investigate the edited strains after curing of the base editor plasmid. The off-targets present were characteristic of Cas9-independent off-targeting and point to TC motifs as activity hotspots of the cytidine deaminase used. We anticipate that CRISPR-mediated base editing is the start of "engineering the engineer," leading to improved Agrobacterium strains for more efficient plant transformation and gene editing

Bedside monitoring of anticoagulation in chronic haemodialysis patients treated with tinzaparin

Background. During haemodialysis, anticoagulants are required to prevent clotting in the extracorporeal circuit. Low-molecular weight heparins (LMWH) are frequently used because of the ease of a single injection at the start of dialysis. Disadvantages of LMWH include the lack of a reliable bedside assay for measuring their anticoagulant effect. Methods. We investigated a bedside test for LMWH activity. The relationship between anti-Xa (chromogenic assay) and Hemonox point-of-care assay was evaluated in 21 dialysis patients (12 men and 9 women) with a median age of 71 years, receiving tinzaparin at the start of a haemodiafiltration session. Results. At the start, before tinzaparin administration, median (interquartile ranges) of Hemonox values were 74 (67–82) s. Thirty minutes after tinzaparin administration, Hemonox values were increased to 496 (360–736) s, followed by a decrease to 149 (135–301) s after 120 min, 102 (97–144) s after 180 min and 92 (83–100) s after 240 min. Corresponding anti-Xa activities were 0 (0–0), 1.12 (0.9–1.29), 0.74 (0.57–0.96), 0.47 (0.31–0.7) and 0.31(0.16–0.49) IU/mL. Hemonox values showed an exponential relation to anti-Xa levels. Interchangeability of tests was shown by Bland–Altman plot. Conclusion. Point-of-care Hemonox test is a valuable bedside method for monitoring anti-Xa activity in dialysis patients anticoagulated with tinzaparin

The use of magnetic resonance imaging in forensic age estimation of living children and subadults systematically reviewed

Purpose: To systematically review the use of MRI in forensic age estimation of living children and subadults. To provide a comprehensive overview that can guide age estimation practice and future research. Search methods: The following databases were searched: MEDLINE, Embase and Web of Science. Additionally, reference lists of included articles, citing articles and study registers were searched. No restrictions were made based on the country of publication, language or publication date. Selection criteria: Two review authors independently selected articles based on titles and abstracts. Study populations including living subjects up to 30 years were considered. MRI of any field strength studying the development of anatomical structures related to age were included. Studies with unclear or doubtful outcome were excluded. Cross-sectional observational studies, pilot studies, cohort studies and case reports were included. Review articles and pilot studies of other references were excluded. After achieving a consensus regarding the selection of articles, the full text papers were independently evaluated for eligibility by two reviewers. Data extraction and analysis: The authors independently developed study characteristics tables and data extraction tables for the included articles. A risk of bias assessment tool was developed, based on the EPOC overview and QUADAS-2. Authors were contacted for further details and data if these were unclear, missing or in a format unsuitable for analysis. Results: After deduplication, 391 records were screened based on title and abstract, rendering 84 eligible articles. Citation tracking rendered 16 additional articles. After full-text screening, 55 studies were included in qualitative analysis and 33 in quantitative analysis. Most studies included European (Caucasian) populations. Only regarding hand/wrist were African, Asian and Latin American populations studied too. However, studies were highly biased by their study populations and MR-sequences varied widely, as did staging techniques. Therefore, pooling of the age distribution data was not appropriate. Still, the studies suggested that combining third molars, the left hand/wrist and the knee would have the strongest potential to estimate age accurately in females. In males, combining third molars, the proximal humerus and the knee might be ideal. Age estimation performance was in line with the gold standard, which uses radiographs, with mean absolute errors ranging from 0.85 to 2.0 years. The proportion of correctly classified minors ranged from 65% to 91%.status: publishe

Professionalisering van lerarenopleiders via praktijkonderzoek

Professionalisering en onderzoekende houding van lerarenopleiders zijn belangrijke thema’s in (inter)nationaal beleid en onderzoek. Het voorgestelde project speelt hierop in via de opzet van een professionaliseringstraject rond praktijkonderzoek voor leraren. De laatste jaren wordt in literatuur en beleid op nationaal en internationaal vlak steeds meer aandacht gegeven aan de professionalisering van de lerarenopleider (Campbell et al, 2013). Zo is er de Europese oproep tot een verhoogde aandacht voor de professionaliteit van de lerarenopleider (European Commission, 2010) en verwijst Nederlands onderzoek naar het gebrek aan overeenstemming over de rol van ‘onderzoeker’ van de lerarenopleider (Lunenberg et al, 2013). Maar ook in Vlaanderen staat dit hoog op de agenda (beleidsevaluatie lerarenopleiding, 2013). Ook nam VELOV in 2012 in het ontwikkelingsprofiel Vlaamse lerarenopleider uitdrukkelijk de rubriek ‘lerarenopleider als innovator & onderzoeker’ op. Op de conferentie worden de eerste voorlopige bevindingen gepresenteerd

Professionalisering van lerarenopleiders via praktijkonderzoek

De laatste jaren wordt in de literatuur en het beleid op nationaal en internationaal vlak veel aandacht besteed aan de professionalisering van de lerarenopleider (Campbell et al, 2013). Dit wordt zowel in Nederland als in Vlaanderen o.a. benadrukt door ‘de lerarenopleider als onderzoeker’ expliciet op te nemen in respectievelijk de beroepsstandaard voor lerarenopleiders (VELON, 2012) en het Vlaams ontwikkelingsprofiel voor lerarenopleiders (VELOV, 2012). Uit verschillende studies blijkt dat praktijkonderzoek een grote rol kan spelen in de professionalisering van leraren en lerarenopleiders (Cochran-Smith & Lytle, 2009; Maes, Clarebout, et al, 2012). Hieronder verstaan we het onderzoeken van de eigen onderwijspraktijk met als hoofddoel de uitkomsten van dat onderzoek te gebruiken om de eigen onderwijspraktijk te verbeteren (Lunenberg et al., 2009). Praktijkonderzoek staat dan in functie van het ontwikkelen van een onderzoekende houding. Om deze onderzoekende houding van lerarenopleiders te versterken, ontwikkelen en organiseren de Arteveldehogeschool, Universiteit Gent en Het Perspectief een professionaliseringstraject. Hierbij leren lerarenopleiders van het expertisenetwerk Associatie Universiteit Gent in samenwerking met collega’s praktijkonderzoek uitvoeren. Het project is evidence-based opgezet. Gedurende de loop van het project wordt namelijk onderzoeksmatig in kaart gebracht wat de effecten en randvoorwaarden zijn voor het stimuleren van onderzoeksvaardigheden van lerarenopleiders om zo professionalisering te ondersteunen

Modulation of the DA1 pathway in maize shows that translatability of information from Arabidopsis to crops is complex

Modern agriculture is struggling to meet the increasing food, silage and raw material demands due to the rapid growth of population and climate change. In Arabidopsis, DA1 and DAR1 are proteases that negatively regulate cell proliferation and control organ size. DA1 and DAR1 are activated by ubiquitination catalyzed by the E3 ligase BIG BROTHER (BB). Here, we characterized the DA1, DAR1 and BB gene families in maize and analyzed whether perturbation of these genes regulates organ size similar to what was observed in Arabidopsis. We generated da1_dar1a_dar1b triple CRISPR maize mutants and bb1_bb2 double mutants. Detailed phenotypic analysis showed that the size of leaf, stem, cob, and seed was not consistently enlarged in these mutants. Also overexpression of a dominant-negative DA1R333K allele, resembling the da1-1 allele of Arabidopsis which has larger leaves and seeds, did not alter the maize phenotype. The mild negative effects on plant height of the DA1R333K_bb1_bb2 mutant indicate that the genes in the DA1 pathway may control organ size in maize, albeit less obvious than in Arabidopsis