33 research outputs found

    Size-correlated division of labour and spatial distribution of workers in the driver ant, Dorylus molestus

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    Driver ants ( Dorylus spp.) show a high degree of worker polymorphism. Previous reports suggest that large Dorylus workers are specialised for defensive tasks. In this study, we first quantitatively tested whether there is a size-correlated division of defensive labour among workers. Second, we determined whether the spatial distribution of workers outside the nest can be predicted based on such size-specific differences in task allocation. We show that the division of defensive behaviour among different-sized workers is not strict. However, there is a significant correlation between worker size and the tendency to carry out defensive tasks. First, workers of larger size were more likely than smaller workers to participate in colony defence. Second, larger workers were more frequent near the nest containing the reproducing individuals and the brood. Finally, large workers were more common in open sections of the trail than in covered sections, which are likely to be less exposed to predators

    Xenotransplantation for CNS repair : immunological barriers and strategies to overcome them

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    Neural transplantation holds promise for focal CNS repair. Owing to the shortage of human donor material, which is derived from aborted embryos, and ethical concerns over its use, animal donor tissue is now considered an appropriate alternative. In the USA, individuals suffering from Parkinson's disease, Huntington's disease, focal epilepsy or stroke have already received neural grafts from pig embryos. However, in animal models, neural tissue transplanted between species is usually promptly rejected, even when implanted in the brain. Some of the immunological mechanisms that underlie neural xenograft rejection have recently been elucidated, but others remain to be determined and controlled before individuals with neurological disorders can benefit from xenotransplantation

    Activated porcine embryonic brain endothelial cells induce a proliferative human T-lymphocyte response

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    Transplantation of allogeneic embryonic neural tissue is a potential treatment for patients with Parkinson's and Huntington's diseases. The supply of human donor tissue is limited, and alternatives such as the use of animal (e.g., porcine) donor tissue are currently being evaluated. Before porcine grafts can be used clinically, strategies to prevent neural xenograft rejection must be developed. Knowledge on how human T lymphocytes recognize porcine embryonic neural tissue would facilitate the development of such strategies. To investigate the ability of porcine embryonic brain microvascular endothelial cells (PBMEC) to stimulate human T-cell proliferation, PBMEC were immuno-magnetically isolated and cocultured with purified human CD4 or CD8 single-positive T cells. PBMEC had a cobblestone-like growth pattern and expressed the endothelial cell markers CD31 and CD106. PBMEC stimulated with the supernatant of phytohemagglutinin-activated porcine peripheral blood mononuclear cells or porcine IFN-gamma, but not nonstimulated PBMEC, induced proliferation of both CD8 and CD4 T cells as assessed by [H-3]thymidine incorporation. Flow cytometric analyses showed that the degree of CD8 and CD4 T cell proliferation correlated with the expression levels of class I and 11 major histocompatibility complex (MHC) antigens, respectively. PBMEC expressed a CTLA-4/Fc-reactive molecule, most likely CD86, suggesting that these cells are able to deliver a costimulatory signal to the T cells. Human TNF-alpha, but not human IFN-gamma, induced class I, but not class II, MHC expression on PBMEC. Within a neural graft or the regional lymph nodes, PBMEC might stimulate human T cells via the direct pathway, and should therefore be removed from the donor tissue prior to transplantation

    Patient-reported outcomes, health-related quality of life, and acute medication use in patients with a ≥ 75% response to eptinezumab: subgroup pooled analysis of the PROMISE trials

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    Background: PROMISE-1 and PROMISE-2 evaluated the preventive efficacy, tolerability, and safety of eptinezumab, a calcitonin gene-related peptide–targeted monoclonal antibody, in adults with episodic (EM) and chronic migraine (CM), finding significant reductions in migraine frequency. This post hoc analysis compared patient-reported outcomes (PROs), health-related quality of life (HRQoL) and acute medication use in patients with a ≥ 75% migraine responder rate (MRR) after treatment with eptinezumab to patients with a ≥ 50– < 75% MRR. Methods: PROMISE-1 and PROMISE-2 were phase 3, randomized, double-blind, placebo-controlled studies. This analysis included patients from both studies treated with eptinezumab 100 mg or 300 mg who experienced ≥ 75% and ≥ 50–< 75% MRR over Weeks 1–12 (wks1–12). In both studies, HRQoL was measured by the 36-item Short-Form Health Survey (SF-36) and acute medication usage. PROMISE-2 also included the 6-item Headache Impact Test (HIT-6), patient-identified most bothersome symptom (PI-MBS), and Patient Global Impression of Change (PGIC). Results: In PROMISE-1, a total of 115/443 (26.0%; 100 mg, n = 49, 300 mg, n = 66) and 120/443 (27.0%; 100 mg, n = 61, 300 mg, n = 59) eptinezumab-treated patients achieved ≥ 75% and ≥ 50–< 75% MRR over wks1–12, respectively. In PROMISE-2, a total of 211/706 (30.0%; 100 mg, n = 95; 300 mg, n = 116) and 209/706 (29.6%; 100 mg, n = 110, 300 mg, n = 99) eptinezumab-treated patients achieved ≥ 75% and ≥ 50–< 75% MRR over wks1–12, respectively. EM and CM patients with ≥ 75% and ≥ 50–< 75% MRR over wks1–12 showed reduced use of acute headache medication and increased HRQoL to normative levels across SF-36 domains of bodily pain, social functioning, and physical functioning. In CM patients with ≥ 75% and ≥ 50–< 75% MRR over wks1–12, the mean change in HIT-6 total score with eptinezumab (pooled) was − 11.7 and − 7.6, respectively. “Very much” or “much” improvement responses were reported in 41.8% and 16.5% on PI-MBS and 36.2% and 20.0% on PGIC in ≥ 75% and ≥ 50–< 75% MRR, respectively. Conclusion: Eptinezumab treatment induced a ≥ 75% MRR over wks1–12 in the majority of patients. This patient subgroup reported substantial improvements in PROs associated with headache-related life impact and HRQoL, and reductions in acute headache medication use, which were more marked than those in the ≥ 50–< 75% responders. This study supports the clinical meaningfulness of ≥ 75% MRR for patients with either EM or CM. Trial registration: ClinicalTrials.gov identifiers: NCT02559895 (PROMISE-1), NCT02974153 (PROMISE-2)
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