71 research outputs found

    Adenoviral gene transfer of angiostatic ATF-BPTI inhibits tumour growth

    Get PDF
    BACKGROUND: The outgrowth of new vessels – angiogenesis – in the tumour mass is considered to be a limiting factor of tumour growth. To inhibit the matrix lysis that is part of the tumour angiogenesis, we employed the chimeric protein mhATF-BPTI, composed of the receptor binding part of the urokinase (ATF) linked to an inhibitor of plasmin (BPTI). METHODS: For delivery, recombinant adenovirus encoding the transgene of interest was injected intravenously or locally into the tumour. The anti tumour effect of this compound was compared to that of human endostatin and of mhATF alone in two different rat bronchial carcinomas growing either as subcutaneous implants or as metastases. RESULTS: Significant inhibition of the tumour growth and decrease of the number of lung metastasis was achieved when the concentration of mhATF-BPTI at the tumour site was above 400 of ng / g tissue. This concentration could be achieved via production by the liver, only if permissive to the recombinant adenovirus. When the tumour cells could be transduced, local delivery of the vector was enough to obtain a response. In the case of metastasis, the capacity of the lung tissue to concentrate the encoded protein was essential to reach the required therapeutic levels. Further, endostatin or mhATF could not reproduce the effects of mhATF-BPTI, at similar concentrations (mhATF) and even at 10-fold higher concentration (endostatin). CONCLUSION: The ATF-BPTI was shown to inhibit tumour growth of different rat lung tumours when critical concentration was reached. In these tumour models, endostatin or ATF induce almost no tumour response

    Strengths and limitations of period estimation methods for circadian data

    Get PDF
    A key step in the analysis of circadian data is to make an accurate estimate of the underlying period. There are many different techniques and algorithms for determining period, all with different assumptions and with differing levels of complexity. Choosing which algorithm, which implementation and which measures of accuracy to use can offer many pitfalls, especially for the non-expert. We have developed the BioDare system, an online service allowing data-sharing (including public dissemination), data-processing and analysis. Circadian experiments are the main focus of BioDare hence performing period analysis is a major feature of the system. Six methods have been incorporated into BioDare: Enright and Lomb-Scargle periodograms, FFT-NLLS, mFourfit, MESA and Spectrum Resampling. Here we review those six techniques, explain the principles behind each algorithm and evaluate their performance. In order to quantify the methods' accuracy, we examine the algorithms against artificial mathematical test signals and model-generated mRNA data. Our re-implementation of each method in Java allows meaningful comparisons of the computational complexity and computing time associated with each algorithm. Finally, we provide guidelines on which algorithms are most appropriate for which data types, and recommendations on experimental design to extract optimal data for analysis

    Temporal regularity of the environment drives time perception

    Get PDF
    It’s reasonable to assume that a regularly paced sequence should be perceived as regular, but here we show that perceived regularity depends on the context in which the sequence is embedded. We presented one group of participants with perceptually regularly paced sequences, and another group of participants with mostly irregularly paced sequences (75% irregular, 25% regular). The timing of the final stimulus in each sequence could be varied. In one experiment, we asked whether the last stimulus was regular or not. We found that participants exposed to an irregular environment frequently reported perfectly regularly paced stimuli to be irregular. In a second experiment, we asked participants to judge whether the final stimulus was presented before or after a flash. In this way, we were able to determine distortions in temporal perception as changes in the timing necessary for the sound and the flash to be perceived synchronous. We found that within a regular context, the perceived timing of deviant last stimuli changed so that the relative anisochrony appeared to be perceptually decreased. In the irregular context, the perceived timing of irregular stimuli following a regular sequence was not affected. These observations suggest that humans use temporal expectations to evaluate the regularity of sequences and that expectations are combined with sensory stimuli to adapt perceived timing to follow the statistics of the environment. Expectations can be seen as a-priori probabilities on which perceived timing of stimuli depend

    Calcium orthophosphate-based biocomposites and hybrid biomaterials

    Full text link

    Allogeneic stem cell transplantation in X-linked lymphoproliferative disease: two cases in one family and review of the literature

    No full text
    Summary:X-linked lymphoproliferative disease (XLP) is a rare immunodeficiency caused by mutations in the signaling lymphocyte activating molecule-associated protein/SH2D1A gene and characterized by a dysregulated immune response to Epstein-Barr virus and other pathogens. The clinical presentation is heterogeneous and includes fulminant infectious mononucleosis, lymphoma, hypogammaglobulinemia and aplastic anemia. XLP is associated with a high morbidity and overall outcome is poor. At present, allogeneic stem cell transplantation (alloSCT) is the only curative treatment. XLP patients may be recognized in various stages of disease and even when symptoms are not yet evident. We here present two related XLP patients in different stages of disease that were both treated successfully with alloSCT using a matched unrelated donor. In addition, we have reviewed all reported cases of alloSCTs in XLP patients. Based on these results and in order to improve the final outcome, we conclude that alloSCT should be recommended in both symptomatic and asymptomatic XLP patients.Bone Marrow Transplantation advance online publication, 23 May 2005; doi:10.1038/sj.bmt.170501

    Comparison of blood services and clinical transfusion practices in Zimbabwe and the Netherlands: What are the key lessons?

    Get PDF
    IntroductionTracking blood safety status of member states by World Health Organisation is now a routine activity through Global Database for Blood Safety. To understand further the differences between high income and low-income countries a detailed review may be warranted. In this review, the blood services of Netherlands and Zimbabwe were compared.MethodologyA study visit to Netherlands was undertaken and the key findings from this visit were compared with equivalent data from Zimbabwe. Key thematic points were summarised from the review of the reports as well as the outcomes from key observations and informant discussions. Lessons learnt and recommendations were drawn for each thematic area considered.Key FindingsThe difference in geographical land sizes (Zimbabwe 10 times larger) and population demographics (Zimbabwe predominately youths) poses different challenges to Netherlands and Zimbabwe. The organisation and management structures of the Services are similar and both rely on 100% voluntary non-remunerated blood donors. Despite the high transfusion transmission infections (TTI) rates in the general population in Zimbabwe the testing technology is low as compared to Netherlands. However, Zimbabwe through other strategies has managed to maintain low TTI prevalence in donated blood. There are comparable efforts in blood process, testing and distribution activities. The support services such as haemovigilance, research and development activities are greatly comparable though the outputs magnitude will differ depending of the level of investment.ConclusionOur findings seems to suggest that despite the differing income status of countries, given the proper strategies blood services in low resources settings can make comparable achievement
    corecore