74 research outputs found

    Self-complementary AAV Virus (scAAV) Safe and Long-term Gene Transfer in the Trabecular Meshwork of Living Rats and Monkeys

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    AAV vectors produce stable transgene expression and elicit low immune response in many tissues. AAVs have been the vectors of choice for gene therapy for the eye, in particular the retina. scAAVs are modified AAVs that bypass the required second-strand DNA synthesis to achieve transcription of the transgene. The goal was to investigate the ability of AAV vectors to induce long-term, safe delivery of transgenes to the trabecular meshwork of living animals

    B cell depletion therapy ameliorates autoimmune disease through ablation of IL-6–producing B cells

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    B cells have paradoxical roles in autoimmunity, exerting both pathogenic and protective effects. Pathogenesis may be antibody independent, as B cell depletion therapy (BCDT) leads to amelioration of disease irrespective of autoantibody ablation. However, the mechanisms of pathogenesis are poorly understood. We demonstrate that BCDT alleviates central nervous system autoimmunity through ablation of IL-6–secreting pathogenic B cells. B cells from mice with experimental autoimmune encephalomyelitis (EAE) secreted elevated levels of IL-6 compared with B cells from naive controls, and mice with a B cell–specific IL-6 deficiency showed less severe disease than mice with wild-type B cells. Moreover, BCDT ameliorated EAE only in mice with IL-6–sufficient B cells. This mechanism of pathogenesis may also operate in multiple sclerosis (MS) because B cells from MS patients produced more IL-6 than B cells from healthy controls, and this abnormality was normalized with B cell reconstitution after Rituximab treatment. This suggests that BCDT improved disease progression, at least partly, by eliminating IL-6–producing B cells in MS patients. Taking these data together, we conclude that IL-6 secretion is a major mechanism of B cell–driven pathogenesis in T cell–mediated autoimmune disease such as EAE and MS

    Anti-cancer drug validation: the contribution of tissue engineered models

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    Abstract Drug toxicity frequently goes concealed until clinical trials stage, which is the most challenging, dangerous and expensive stage of drug development. Both the cultures of cancer cells in traditional 2D assays and animal studies have limitations that cannot ever be unraveled by improvements in drug-testing protocols. A new generation of bioengineered tumors is now emerging in response to these limitations, with potential to transform drug screening by providing predictive models of tumors within their tissue context, for studies of drug safety and efficacy. Considering the NCI60, a panel of 60 cancer cell lines representative of 9 different cancer types: leukemia, lung, colorectal, central nervous system (CNS), melanoma, ovarian, renal, prostate and breast, we propose to review current Bstate of art^ on the 9 cancer types specifically addressing the 3D tissue models that have been developed and used in drug discovery processes as an alternative to complement their studyThis article is a result of the project FROnTHERA (NORTE-01-0145-FEDER-000023), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This article was also supported by the EU Framework Programme for Research and Innovation HORIZON 2020 (H2020) under grant agreement n° 668983 — FoReCaST. FCT distinction attributed to Joaquim M. Oliveira (IF/00423/2012) and Vitor M. Correlo (IF/01214/2014) under the Investigator FCT program is also greatly acknowledged.info:eu-repo/semantics/publishedVersio

    Melanoma Spheroids Grown Under Neural Crest Cell Conditions Are Highly Plastic Migratory/Invasive Tumor Cells Endowed with Immunomodulator Function

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    International audienceBACKGROUND: The aggressiveness of melanoma tumors is likely to rely on their well-recognized heterogeneity and plasticity. Melanoma comprises multi-subpopulations of cancer cells some of which may possess stem cell-like properties. Although useful, the sphere-formation assay to identify stem cell-like or tumor initiating cell subpopulations in melanoma has been challenged, and it is unclear if this model can predict a functional phenotype associated with aggressive tumor cells. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed the molecular and functional phenotypes of melanoma spheroids formed in neural crest cell medium. Whether from metastatic or advanced primary tumors, spheroid cells expressed melanoma-associated markers. They displayed higher capacity to differentiate along mesenchymal lineages and enhanced expression of SOX2, NANOG, KLF4, and/or OCT4 transcription factors, but not enhanced self-renewal or tumorigenicity when compared to their adherent counterparts. Gene expression profiling attributed a neural crest cell signature to these spheroids and indicated that a migratory/invasive and immune-function modulating program could be associated with these cells. In vitro assays confirmed that spheroids display enhanced migratory/invasive capacities. In immune activation assays, spheroid cells elicited a poorer allogenic response from immune cells and inhibited mitogen-dependent T cells activation and proliferation more efficiently than their adherent counterparts. Our findings reveal a novel immune-modulator function of melanoma spheroids and suggest specific roles for spheroids in invasion and in evasion of antitumor immunity. CONCLUSION/SIGNIFICANCE: The association of a more plastic, invasive and evasive, thus a more aggressive tumor phenotype with melanoma spheroids reveals a previously unrecognized aspect of tumor cells expanded as spheroid cultures. While of limited efficiency for melanoma initiating cell identification, our melanoma spheroid model predicted aggressive phenotype and suggested that aggressiveness and heterogeneity of melanoma tumors can be supported by subpopulations other than cancer stem cells. Therefore, it could be constructive to investigate melanoma aggressiveness, relevant to patients and clinical transferability

    Potential immunological consequences of pharmacological suppression of gastric acid production in patients with multiple sclerosis

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    Corticosteroids are standard treatment for patients with multiple sclerosis experiencing acute relapse. Because dyspeptic pain is a common side effect of this intervention, patients can be given a histamine receptor-2 antagonist, proton pump inhibitor or antacid to prevent or ameliorate this disturbance. Additionally, patients with multiple sclerosis may be taking these medications independent of corticosteroid treatment. Interventions for gastric disturbances can influence the activation state of the immune system, a principal mediator of pathology in multiple sclerosis. Although histamine release promotes inflammation, activation of the histamine receptor-2 can suppress a proinflammatory immune response, and blocking histamine receptor-2 with an antagonist could shift the balance more towards immune stimulation. Studies utilizing an animal model of multiple sclerosis indicate that histamine receptor-2 antagonists potentially augment disease activity in patients with multiple sclerosis. In contrast, proton pump inhibitors appear to favor immune suppression, but have not been studied in models of multiple sclerosis. Antacids, histamine receptor-2 antagonists and proton pump inhibitors also could alter the intestinal microflora, which may indirectly lead to immune stimulation. Additionally, elevated gastric pH can promote the vitamin B12 deficiency that patients with multiple sclerosis are at risk of developing. Here, we review possible roles of gastric acid inhibitors on immunopathogenic mechanisms associated with multiple sclerosis

    Inhalational versus Intravenous Induction of Anesthesia in Children with a High Risk of Perioperative Respiratory Adverse Events

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    BACKGROUND: Limited evidence suggests that children have a lower incidence of perioperative respiratory adverse events when intravenous propofol is used compared with inhalational sevoflurane for the anesthesia induction. Limiting these events can improve recovery time as well as decreasing surgery waitlists and healthcare costs. This single center open-label randomized controlled trial assessed the impact of the anesthesia induction technique on the occurrence of perioperative respiratory adverse events in children at high risk of those events. METHODS: Children (N = 300; 0 to 8 yr) with at least two clinically relevant risk factors for perioperative respiratory adverse events and deemed suitable for either technique of anesthesia induction were recruited and randomized to either intravenous propofol or inhalational sevoflurane. The primary outcome was the difference in the rate of occurrence of perioperative respiratory adverse events between children receiving intravenous induction and those receiving inhalation induction of anesthesia. RESULTS: Children receiving intravenous propofol were significantly less likely to experience perioperative respiratory adverse events compared with those who received inhalational sevoflurane after adjusting for age, sex, American Society of Anesthesiologists physical status and weight (perioperative respiratory adverse event: 39/149 [26%] vs. 64/149 [43%], relative risk [RR]: 1.7, 95% CI: 1.2 to 2.3, P = 0.002, respiratory adverse events at induction: 16/149 [11%] vs. 47/149 [32%], RR: 3.06, 95% CI: 1.8 to 5.2, P < 0.001). CONCLUSIONS: Where clinically appropriate, anesthesiologists should consider using an intravenous propofol induction technique in children who are at high risk of experiencing perioperative respiratory adverse events. VISUAL ABSTRACT: An online visual overview is available for this article at http://links.lww.com/ALN/B725

    Deep or awake removal of laryngeal mask airway in children at risk of respiratory adverse events undergoing tonsillectomy—a randomised controlled trial

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    Background: Laryngeal mask airways (LMA) are widely used during tonsillectomies. Contrasting evidence exists regarding the timing of the removal and the risk of perioperative respiratory adverse events. We assessed whether the likelihood of perioperative respiratory adverse events is influenced by the timing of LMA removal in children with at least one risk factor for these events. Methods: Participants (n=290, 0–16 yr) were randomised to have their LMA removed either deep (in theatre by anaesthetist at end-tidal sevoflurane >1 minimum alveolar concentration) or awake (in theatre by anaesthetist or in postanaesthesia care unit by anaesthetist or trained nurse). The primary outcome was the occurrence of perioperative respiratory adverse events over the whole emergence and postanaesthesia care unit phases of anaesthesia. The secondary outcome was the occurrence of perioperative respiratory adverse events over the distinct phases of emergence and postanaesthesia care unit. Results: Data from 283 participants were analysed. Primary outcome: even though a higher occurrence of adverse events was observed in the awake group, no evidence for a difference was found [45% vs 35%, odds ratio (OR): 1.5, 95% confidence interval (CI): 0.9–2.5, P=0.09]. Secondary outcome: there was no evidence for a difference between the groups during emergence [19 (14%) deep vs 25 (18%) awake, OR: 0.74, 95%CI: 0.39–1.42, P=0.37]. However, in the postanaesthesia care unit, children with an awake rather than deep removal experienced significantly more adverse events [55 (39%) vs 37 (26%); OR: 1.85, 95%CI: 1.12–3.07, P=0.02]. Conclusion: We found no evidence for a difference in the timing of the LMA removal on the incidence of respiratory adverse events over the whole emergence and postanaesthesia care unit phases. However, in the postanaesthesia care unit solely, awake removal was associated with significantly more respiratory adverse events than deep removal. Trial registration number: ACTRN12609000387224 (www.anzctr.org.au)

    The effect of endotracheal tubes versus laryngeal mask airways on perioperative respiratory adverse events in infants: a randomised controlled trial

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    Background: Perioperative respiratory adverse events (PRAE) are the most common critical incidents in paediatric anaesthesia and occur more often in infants. Use of laryngeal mask airways (LMAs) is associated with reduced PRAE compared with endotracheal tubes in older children (>1 year). We aimed to evaluate the effect of these devices on the incidence of PRAE in infants. Methods: We did a randomised controlled trial at the Princess Margaret Hospital for Children in Perth (WA, Australia) by recruiting infants (aged 0–12 months) undergoing general (with or without regional or local) anaesthesia with anticipated fentanyl dose 1 µg/kg or lower for minor elective surgery. We excluded patients contraindicated for LMA or endotracheal tube; who had known cardiac disease or airway or thoracic malformations; who were receiving midazolam premedication; who were undergoing airway, thoracic, or abdomen surgery at the time of participation; and if the parents did not speak English. Written parental or guardian consent was obtained before enrolment. Participants were randomly assigned (1:1), by computer-generated variable block randomisation, to receive an LMA (PRO-Breathe, Well Lead Medical Co Ltd, Panyu, China) or an endotracheal tube (Microcuff, Halyard Health Inc, Atlanta, GA, USA). Sealed randomisation envelopes were used to conceal device assignment. An interim analysis was planned once half the number of infants needed (145) had been recruited. The primary outcome was incidence of PRAE, assessed in the intention-to-treat population. The institutional ethics committee at the Princess Margaret Hospital for Children granted ethical approval (1786/EP). The trial is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12610000250033). Findings: The trial began on July 8, 2010, and was ended early on May 7, 2015, after the interim analysis results met the study stopping rules. During this time, 239 infants were assessed and 181 eligible infants were randomly assigned to receive an LMA (n=85) or an endotracheal tube (n=95). Four infants were not included in the analysis (two due to cancelled procedures, one did not meet inclusion criteria, and one with missing dataset). In the intention-to-treat analysis, PRAE occurred in 50 (53%) infants in the endotracheal tube group and in 15 (18%) infants in the LMA group (risk ratio [RR] 2·94, 95% CI 1·79–4·83, p<0·0001). Laryngospasm and bronchospasm (major PRAE) were recorded in 18 (19%) infants in the endotracheal tube group and in three (4%) infants in the LMA group (RR 5·30, 95% CI 1·62–17·35, p=0·002). No deaths were reported. Interpretation In infants undergoing minor elective procedures, LMAs were associated with clinically significantly fewer PRAE and lower occurrence of major PRAE (laryngospasm and bronchospasm) than endotracheal tubes. This difference should be a consideration in airway device selection. Funding Princess Margaret Hospital Foundation, National Health and Australian Medical Research Council, Stan Perron Charitable Trust, and Callahan Estate
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