477 research outputs found

    In vitro analysis, an accurate tool to estimate dry matter digestibility in rabbits. Intra- and inter- laboratory variability

    Full text link
    [EN] The aim of the present study was to determine the intra- and inter-laboratory variability of an enzymatic system of in vitro analysis for estimating dry matter (DM) digestibility in rabbits and validating the predicted nutritive value of 4 complete diets and 4 raw materials during three different periods of time. Chemical composition, DM digestibility and digestible energy (diets only) were known. In vitro DM digestibility (DMdinv) of all samples was determined by 4 laboratories (triplicate analysis) at different times with an interval of one month between analyses. DMdinv variability and chemical parameters were measured in terms of repeatability (SR: intra-series variability within each laboratory), reproducibility (SL: intra-series variability among laboratories) and reliability (SF: variability through time within each laboratory). Both the laboratory and sample affected DMdinv values (P<0.001). The period of time also had a significant effect (P=0.002) on mean DMdinv values (67.4, 66.8 and 67.0% for the 1st, 2nd and 3rd month, respectively). Significant laboratory x sample, time x laboratory and time x sample interaction effects were also observed. Repeatability, reproducibility and reliability values for the diets were better than those obtained for the raw materials (by 2.0, 1.9 and 2.4 times, respectively). Repeatability values were also better than the values obtained for reproducibility and reliability (by 2.2 and 3.6 times, respectively). Repeatability and reproducibility values were consistently worse for raw materials than for complete diets (by 1.5, 4, 2.9 and 1.3, 4.3, 2.8 times for SR and SL in period 1, period 2 and period 3, respectively), and were also worse in period 1 with respect to the other two periods (by 2.1 and 2.2 times for SR and SL, respectively). Finally, the in vitro method always showed better coefficients of variation of repeatability (CVR) and reproducibility (CVL) than those of the chemical parameters frequently used as predictors of dietary energy value (acid detergent fibre and crude fibre) (1.73 vs. 2.41 and 3.88 for CVR and 3.24 vs. 3.70 and 5.17 for CVL, respectively). In conclusion, the proposed in vitro methodology showed adequate repeatability and reproducibility, being suitable for predictive purposes.This research was supported by ERAFE project CE-FAIR (3-CT96-1651)Carabaño, R.; Nicodemus, N.; García, J.; Xiccato, G.; Trocino, A.; Pascual Amorós, JJ.; Falcão-E-Cunha, L.... (2008). In vitro analysis, an accurate tool to estimate dry matter digestibility in rabbits. Intra- and inter- laboratory variability. World Rabbit Science. 16(4). doi:10.4995/wrs.2008.614SWORD16

    Toward Good Read-Across Practice (GRAP) guidance.

    Get PDF
    Grouping of substances and utilizing read-across of data within those groups represents an important data gap filling technique for chemical safety assessments. Categories/analogue groups are typically developed based on structural similarity and, increasingly often, also on mechanistic (biological) similarity. While read-across can play a key role in complying with legislations such as the European REACH regulation, the lack of consensus regarding the extent and type of evidence necessary to support it often hampers its successful application and acceptance by regulatory authorities. Despite a potentially broad user community, expertise is still concentrated across a handful of organizations and individuals. In order to facilitate the effective use of read-across, this document aims to summarize the state-of-the-art, summarizes insights learned from reviewing ECHA published decisions as far as the relative successes/pitfalls surrounding read-across under REACH and compile the relevant activities and guidance documents. Special emphasis is given to the available existing tools and approaches, an analysis of ECHA's published final decisions associated with all levels of compliance checks and testing proposals, the consideration and expression of uncertainty, the use of biological support data and the impact of the ECHA Read-Across Assessment Framework (RAAF) published in 2015

    Syngeneic transplantation in aplastic anemia: pre-transplant conditioning and peripheral blood are associated with improved engraftment: an observational study on behalf of the Severe Aplastic Anemia and Pediatric Diseases Working Parties of the European Group for Blood and Marrow Transplantation

    Full text link
    Aplastic anemia is usually treated with immunosuppression or allogeneic transplant, depending on patient and disease characteristics. Syngeneic transplant offers a rare treatment opportunity with minimal transplant-related mortality, and offers an insight into disease mechanisms. We present here a retrospective analysis of all syngeneic transplants for aplastic anemia reported to the European Group for Blood and Marrow Transplantation. Between 1976 and 2009, 88 patients received 113 transplants. Most transplants (n=85) were preceded by a conditioning regimen, 22 of these including anti-thymocyte globulin. About half of transplants with data available (39 of 86) were followed by posttransplant immunosuppression. Graft source was bone marrow in the majority of cases (n=77). Transplant practice changed over time with more transplants with conditioning and anti-thymocyte globulin as well as peripheral blood stem cells performed in later years. Ten year overall survival was 93% with 5 transplant-related deaths. Graft failure occurred in 32% of transplants. Risk of graft failure was significantly increased in transplants without conditioning, and with bone marrow as graft source. Lack of posttransplant immunosuppression also showed a trend towards increased risk of graft failure, while anti-thymocyte globulin did not have an influence. In summary, syngeneic transplant is associated with a significant risk of graft failure when no conditioning is given, but has an excellent long-term outcome. Furthermore, our comparatively large series enables us to recommend the use of pre-transplant conditioning rather than not and possibly to prefer peripheral blood as a stem cell source

    An observational efficacy and safety analysis of the treatment of acute invasive aspergillosis using voriconazole

    Get PDF
    The purpose of this study was to evaluate efficacy and safety of voriconazole in patients with acute invasive aspergillosis (IA) in a real-life, clinical setting. This was a multicenter observational study in adult patients treated with voriconazole for invasive mycosis. The study evaluated clinical response, mortality, use of other licensed antifungal therapy (OLAT), and treatment duration. This sub-analysis evaluated treatment and outcome data specifically from adult patients with proven/probable IA, while safety data were assessed in patients with proven/probable/possible IA. Of the 141 patients enrolled, 113 were adults with proven/probable IA and six had possible IA. Voriconazole treatment duration ranged from 1 to 183 days (median, 49.5 days). Voriconazole was used exclusively in 64% (72/113) of patients and in combination/sequentially with OLAT in 36%. Overall successful treatment response was 50% (57/113 patients). Twelve percent (14/113) of patients were switched to OLAT, either because of insufficient response (four patients) or for safety reasons (10 patients). Overall and attributable (entirely or partially due to fungal infection) mortality rates were 52% (59/113) and 17%, respectively. Treatment-related adverse events were reported for 18% (22/119) of patients. This observational study confirms the results of previous clinical trials demonstrating voriconazole as an effective and safe agent for treatment of confirmed acute IA

    A phase IV, multi-centre, randomized clinical trial comparing two pertussis-containing vaccines in pregnant women in England and vaccine responses in their infants.

    Get PDF
    BACKGROUND: Pertussis vaccines containing three or five pertussis antigens are recommended in pregnancy in many countries, but no studies have compared the effect on infants' antigen-specific immunoglobulin G (IgG) concentrations. The aim of this study was to compare anti-pertussis IgG responses following primary immunization in infants of mothers vaccinated with TdaP5-IPV (low dose diphtheria toxoid, tetanus toxoid, acellular pertussis [five antigens] and inactivated polio) or TdaP3-IPV in pregnancy (three pertussis antigens). METHODS: This multi-centre phase IV randomized clinical trial was conducted in a tertiary referral centre and primary care sites in England. Women were randomized to receive TdaP5-IPV (n = 77) or TdaP3-IPV (n = 77) at 28-32 gestational weeks. A non-randomized control group of 44 women who had not received a pertussis-containing vaccine in pregnancy and their 47 infants were enrolled post-partum. RESULTS: Following infant primary immunization, there was no difference in the geometric mean concentrations (GMCs) of anti-pertussis toxin, filamentous haemagglutinin or pertactin IgG between infants born to women vaccinated with TdaP5-IPV (n = 67) or TdaP3-IPV (n = 63). However, the GMC of anti-pertussis toxin IgG was lower in infants born to TdaP5-IPV- and TdaP3-IPV-vaccinated mothers compared to infants born to unvaccinated mothers (n = 45) (geometric mean ratio 0.71 [0.56-0.90] and 0.78 [0.61-0.98], respectively); by 13 months of age, this difference was no longer observed. CONCLUSION: Blunting of anti-pertussis toxin IgG response following primary immunization occurs in infants born to women vaccinated with TdaP5-IPV and TdaP3-IPV, with no difference between maternal vaccines. The blunting effect had resolved by 13 months of age. These results may be helpful for countries considering which pertussis-containing vaccine to recommend for use in pregnancy. TRIAL REGISTRATION: ClinicalTrials.gov , NCT02145624 , registered 23 May 2014

    Peptides derived from the HIV-1 integrase promote HIV-1 infection and multi-integration of viral cDNA in LEDGF/p75-knockdown cells

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The presence of the cellular Lens Epithelium Derived Growth Factor p75 (LEDGF/p75) protein is essential for integration of the Human immunodeficiency virus type 1 (HIV-1) cDNA and for efficient virus production. In the absence of LEDGF/p75 very little integration and virus production can be detected, as was demonstrated using LEDGF/p75-knokdown cells.</p> <p>Results</p> <p>Here we show that the failure to infect LEDGF/p75-knockdown cells has another reason aside from the lack of LEDGF/p75. It is also due to inhibition of the viral integrase (IN) enzymatic activity by an early expressed viral Rev protein. The formation of an inhibitory Rev-IN complex in virus-infected cells can be disrupted by the addition of three IN-derived, cell-permeable peptides, designated INr (IN derived-Rev interacting peptides) and INS (IN derived-integrase stimulatory peptide). The results of the present work confirm previous results showing that HIV-1 fails to infect LEDGF/p75-knockdown cells. However, in the presence of INrs and INS peptides, relatively high levels of viral cDNA integration as well as productive virus infection were obtained following infection by a wild type (WT) HIV-1 of LEDGF/p75-knockdown cells.</p> <p>Conclusions</p> <p>It appears that the lack of integration observed in HIV-1 infected LEDGF/p75-knockdown cells is due mainly to the inhibitory effect of Rev following the formation of a Rev-IN complex. Disruption of this inhibitory complex leads to productive infection in those cells.</p

    Hsmar1 transposition is sensitive to the topology of the transposon donor and the target

    Get PDF
    Hsmar1 is a member of the Tc1-mariner superfamily of DNA transposons. These elements mobilize within the genome of their host by a cut-and-paste mechanism. We have exploited the in vitro reaction provided by Hsmar1 to investigate the effect of DNA supercoiling on transposon integration. We found that the topology of both the transposon and the target affect integration. Relaxed transposons have an integration defect that can be partially restored in the presence of elevated levels of negatively supercoiled target DNA. Negatively supercoiled DNA is a better target than nicked or positively supercoiled DNA, suggesting that underwinding of the DNA helix promotes target interactions. Like other Tc1-mariner elements, Hsmar1 integrates into 5′-TA dinucleotides. The direct vicinity of the target TA provides little sequence specificity for target interactions. However, transposition within a plasmid substrate was not random and some TA dinucleotides were targeted preferentially. The distribution of intramolecular target sites was not affected by DNA topology
    corecore