110 research outputs found

    Genetic research in a public-private research consortium: prospects for indirect use of Elige breeding germplasm in academic research

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    The creation of a publicÂżprivate research partnership between plant breeding industry and academia can be beneficial for all parties involved. Academic partners benefit from the material contributions by industry and a practically relevant research focus, while industry benefits from increased insights and methodology tailored to a relevant set of data. However, plant breeding industry is highly competitive and there are obvious limits to the data and material partners are willing and able to share. This will usually include current and historic released cultivated materials, but will very often not include the elite germplasm used in-house to create new cultivars. Especially for crops where hybrid cultivars dominate the market, parental lines of hybrid cultivars are considered core assets that are never provided to outside parties. However, this limitation often does not apply to DNA or genetic fingerprints of these parental lines. We developed a procedure to take advantage of elite breeding materials for the creation of new promising research populations, through indirect selection of parents. The procedure starts with the identification of a number of traits for further study based on the presence of marker-trait associations and a priori knowledge within the participating companies about promising traits for quality improvement. Next, regression-based multi-QTL models are fitted to hybrid cultivar data to identify QTLs. Fingerprint data of parental lines of a limited number of specific hybrids are then used to predict parental phenotypes using the multi-QTL model fitted on hybrid data. The specific hybrids spanned the whole of the sensory space adequately. Finally, a choice of parental lines is made based on the QTL model predictions and new promising line combinations are identified. Breeding industry is then asked to create and provide progeny of these line combinations for further research. This approach will be illustrated with a case study in tomato

    A tissue-specific knockout reveals that Gata1 is not essential for Sertoli cell function in the mouse

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    The transcription factor Gata1 is essential for the development of erythroid cells. Consequently, Gata1 null mutants die in utero due to severe anaemia. Outside the haematopoietic system, Gata1 is only expressed in the Sertoli cells of the testis. To elucidate the function of Gata1 in the testis, we made a Sertoli cell-specific knockout of the Gata1 gene in the mouse. We deleted a normally functioning 'floxed' Gata1 gene in pre-Sertoli cells in vivo through the expression of Cre from a transgene driven by the Desert Hedgehog promoter. Surprisingly, Gata1 null testes developed to be morphologically normal, spermatogenesis was not obviously affected and expression levels of putative Gata1 target genes, and other Gata factors, were not altered. We conclude that expression of Gata1 in Sertoli cells is not essential for testis development or spermatogenesis in the mouse

    Residual N-acetyl-α-glucosaminidase activity in fibroblasts correlates with disease severity in patients with mucopolysaccharidosis type IIIB

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    Background: Mucopolysaccharidosis type IIIB (MPS IIIB) is a rare genetic disorder in which the deficiency of the lysosomal enzyme N-acetyl-α-glucosaminidase (NAGLU) results in the accumulation of heparan sulfate (HS), leading to progressive neurocognitive deterioration. In MPS IIIB a wide spectrum of disease severity is seen. Due to a large allelic heterogeneity, establishing genotype-phenotype correlations is difficult. However, reliable prediction of the natural course of the disease is needed, in particular for the assessment of the efficacy of potential therapies. Methods: To identify markers that correlate with disease severity, all Dutch patients diagnosed with MPS IIIB were characterised as either rapid (RP; classical, severe phenotype) or slow progressors (SP; non-classical, less severe phenotype), based on clinical data. NAGLU activity and HS levels were measured in patients’ fibroblasts after culturing at different temperatures. Results: A small, though significant difference in NAGLU activity was measured between RP and SP patients after culturing at 37 °C (p < 0.01). Culturing at 30 °C resulted in more pronounced and significantly higher NAGLU activity levels in SP patients (p < 0.001) with a NAGLU activity of 0.58 nmol.mg-1.hr-1 calculated to be the optimal cut-off value to distinguish between the groups (sensitivity and specificity 100 %). A lower capacity of patients’ fibroblasts to increase NAGLU activity at 30 °C could significantly predict for the loss of several disease specific functions. Conclusion: NAGLU activity in fibroblasts cultured at 30 °C can be used to discriminate between RP and SP MPS IIIB patients and the capacity of cells to increase NAGLU activity at lower temperatures correlates with disease symptoms

    Reaction mechanisms in the 6Li+59Co system

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    The reactions induced by the weakly bound 6Li projectile interacting with the intermediate mass target 59Co were investigated. Light charged particles singles and α\alpha-dd coincidence measurements were performed at the near barrier energies E_lab = 17.4, 21.5, 25.5 and 29.6 MeV. The main contributions of the different competing mechanisms are discussed. A statistical model analysis, Continuum-Discretized Coupled-Channels calculations and two-body kinematics were used as tools to provide information to disentangle the main components of these mechanisms. A significant contribution of the direct breakup was observed through the difference between the experimental sequential breakup cross section and the CDCC prediction for the non-capture breakup cross section.Comment: 30 pages, 8 figure

    Short-term prognosis of breakthrough venous thromboembolism in anticoagulated patients

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    Background: Evidence for guideline recommendations for the treatment of venous thromboembolism (VTE) during anticoagulant therapy is scarce. We aimed to observe and to describe the management of VTE occurring during anticoagulant therapy. Methods: This prospective multi-center, observational study included patients with objectively confirmed VTE during anticoagulant therapy (breakthrough event), with a follow-up of 3 months, after the breakthrough event. Results: We registered 121 patients with a breakthrough event, with a mean age of 56 years (range, 19 to 90); 61 were male (50%). Fifty-eight patients (48%) had an active malignancy. At the time of the breakthrough event, 57 patients (47%) were treated with a vitamin K antagonist (VKA), 53 patients (44%) with low-molecular-weight heparin (LMWH) and 11 patients (9%) with direct oral anticoagulants, unfractionated heparin, or VKA plu

    A study on prevalence and determinants of ototoxicity during treatment of childhood cancer (SOUND): protocol for a prospective study

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    Background: Some children with central nervous system (CNS) and solid tumors are at risk to develop ototoxicity during treatment. Up to now, several risk factors have been identified that may contribute to ototoxicity, such as platinum derivates, cranial irradiation, and brain surgery. Comedication, like antibiotics and diuretics, is known to enhance ototoxicity, but their independent influence has not been investigated in childhood cancer patients. Recommendations for hearing loss screening are missing or vary highly across treatment protocols. Additionally, adherence to existing screening guidelines is not always optimal. Currently, knowledge is lacking on the prevalence of ototoxicity. Objective: The aim of the Study on Prevalence and Determinants of Ototoxicity During Treatment of Childhood Cancer (SOUND) is to determine the feasibility of audiological testing and to determine the prevalence and determinants of ototoxicity during treatment for childhood cancer in a national cohort of patients with solid and CNS tumors.Methods: The SOUND study is a prospective cohort study in the national childhood cancer center in the Netherlands. The study aims to include all children aged 0 to 19 years with a newly diagnosed CNS or solid tumor. Part of these patients will get audiological examination as part of their standard of care (stratum 1). Patients in which audiological examination is not the standard of care will be invited for inclusion in stratum 2. Age-dependent audiological assessments will be pursued before the start of treatment and within 3 months after the end of treatment. Apart from hearing loss, we will investigate the feasibility to screen patients for tinnitus and vertigo prevalence after cancer treatment. This study will also determine the independent contribution of antibiotics and diuretics on ototoxicity. Results: This study was approved by the Medical Research Ethics Committee Utrecht (Identifier 20-417/M). Currently, we are in the process of recruitment for this study. Conclusions: The SOUND study will raise awareness about the presence of ototoxicity during the treatment of children with CNS or solid tumors. It will give insight into the prevalence and independent clinical and cotreatment-related determinants of ototoxicity. This is important for the identification of future high-risk patients. Thereby, the study will provide a basis for the selection of patients who will benefit from innovative otoprotective intervention trials during childhood cancer treatment that are currently being prepared.Analysis and Stochastic

    Presence of Epstein-Barr virus latency type III at the single cell level in post- transplantation lymphoproliferative disorders and AIDS related lymphomas

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    AIMS: To investigate the expression pattern of Epstein-Barr virus (EBV) latent genes at the single cell level in post-transplantation lymphoproliferative disorders and acquired immunodefiency syndrome (AIDS) related lymphomas, in relation to cellular morphology. METHODS: Nine post-transplantation lymphoproliferative disorders and three AIDS related lymphomas were subjected to immunohistochemistry using monoclonal antibodies specific for EBV nuclear antigen 1 (EBNA1) (2H4), EBNA2 (PE2 and the new rat anti-EBNA2 monoclonal antibodies 1E6, R3, and 3E9), and LMP1 (CS1-4 and S12). Double staining was performed combining R3 or 3E9 with S12. RESULTS: R3 and 3E9 anti-EBNA2 monoclonal antibodies were more sensitive than PE2, enabling the detection of more EBNA2 positive lymphoma cells. Both in post-transplantation lymphoproliferative disorders and AIDS related lymphomas, different expression patterns were detected at the single cell level. Smaller neoplastic cells were positive for EBNA2 but negative for LMP1. Larger and more blastic neoplastic cells, sometimes resembling Reed-Sternberg cells, were LMP1 positive but EBNA2 negative (EBV latency type II). Morphologically intermediate neoplastic cells coexpressing EBNA2 and LMP1 (EBV latency type III), were detected using R3 and 3E9, and formed a considerable part of the neoplastic population in four of nine post-transplantation lymphoproliferative disorders and two of three AIDS related lymphomas. All samples contained a subpopulation of small tumour cells positive exclusively for Epstein-Barr early RNA and EBNA1. The relation between cellular morphology and EBV expression patterns in this study was less pronounced in AIDS related lymphomas than in post-transplantation lymphoproliferative disorders, because the AIDS related lymphomas were less polymorphic than the post-transplantation lymphoproliferative disorders. CONCLUSIONS: In post-transplantation lymphoproliferative disorders and AIDS related lymphomas, EBV latency type III can be detected by immunohistochemistry in a subpopulation of tumour cells using sensitive monoclonal antibodies R3 and 3E9. Our data suggest that EBV infected tumour cells in these lymphomas undergo gradual changes in the expression of EBV latent genes, and that these changes are associated with changes in cellular morphology

    Prevalence, risk factors, and long-term outcomes of cerebral ischemia in hospitalized COVID-19 patients - study rationale and protocol of the CORONIS study: a multicentre prospective cohort study

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    Background: COVID-19 is often complicated by thrombo-embolic events including ischemic stroke. The underlying mechanisms of COVID-19-associated ischemic stroke, the incidence and risk factors of silent cerebral ischemia, and the long-term functional outcome in these patients are currently unknown. Patients and methods: CORONavirus and Ischemic Stroke (CORONIS) is a multicentre prospective cohort study investigating the prevalence, risk factors and long-term incidence of (silent) cerebral ischemia, and the long-term functional outcome among patients with COVID-19. We aim to include 200 adult patients hospitalized with COVID-19 without symptomatic ischemic stroke to investigate the prevalence of silent cerebral ischemia compared with 60 (matched) controls with MRI. In addition, we will identify potential risk factors and/or causes of cerebral ischemia in COVID-19 patients with (n = 70) or without symptomatic stroke (n = 200) by means of blood sampling, cardiac workup and brain MRI. We will measure functional outcome and cognitive function after 3 and 12 months with standardized questionnaires in all patients with COVID-19. Finally, the long-term incidence of (new) silent cerebral ischemia in patients with COVID-19 will be assessed with follow up MRI (n = 120). The CORONIS study is designed to add further insight into the prevalence, long-term incidence and risk factors of cerebral ischemia, and the long-term functional outcome in hospitalized adult patients with COVID-19.Clinical epidemiolog
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