19 research outputs found

    Retinal safety of intravitreal rtPA in healthy rats and under excitotoxic conditions.

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    Intravitreal recombinant tissue plasminogen activator (rtPA) is used off-label for the surgical management of submacular hemorrhage, a severe complication of neovascular age-related macular degeneration. rtPA is approved for coronary and cerebral thrombolysis. However, in ischemic stroke rtPA is known to increase excitotoxic neural cell death by interacting with the N-methyl-D-aspartate (NMDA) receptor. We therefore investigated the retinal toxicity of rtPA in healthy rats and in a model of NMDA-induced retinal excitotoxicity. First, rtPA at three different doses (2.16 µg/5 µl, 0.54 µg/5 µl, and 0.27 µg/5 µl) or vehicle (NaCl 0.9%) was injected intravitreally in healthy rat eyes. Electroretinograms (ERGs) were performed at 24 h or 7 days. Annexin V-fluorescein isothiocyanate (FITC)-labeled apoptotic retinal ganglion cells (RGCs) were counted on flatmounted retinas at 24 h or 7 days. Next, NMDA + vehicle or NMDA + rtPA (0.27 µg/5 µl) was injected intravitreally to generate excitotoxic conditions. Apoptotic annexin V-FITC-labeled RGCs and surviving Brn3a-labeled RGCs were quantified on flatmounted retinas and radial sections, 18 h after treatment. In healthy rat eyes, the number of apoptotic RGCs was statistically significantly increased 24 h after the administration of rtPA at the highest dose (2.16 µg/5 µl; p = 0.0250) but not at the lower doses of 0.54 and 0.27 µg/5 µl (p = 0.36 and p = 0.20), compared to vehicle. At day 7, there was no difference in the apoptotic RGC count between the rtPA- and vehicle-injected eyes (p = 0.70, p = 0.52, p = 0.11). ERG amplitudes and implicit times were not modified at 24 h or 7 days after injection of any tested rtPA doses, compared to the baseline. Intravitreal administration of NMDA induced RGC death, but under these excitotoxic conditions, coadministration of rtPA did not increase the number of dead RGCs (p = 0.70). Similarly, the number of surviving RGCs on the flatmounted retinas and retinal sections did not differ between the eyes injected with NMDA + vehicle and NMDA + rtPA (p = 0.59 and p = 0.67). At low clinical equivalent doses corresponding to 25 µg/0.1 ml in humans, intravitreal rtPA is not toxic for healthy rat retinas and does not enhance NMDA-induced excitotoxicity. Vitreal equivalent doses ≥200 µg/0.1 ml should be avoided in patients, due to potential RGC toxicity

    Qualification of tumour mutational burden by targeted next-generation sequencing as a biomarker in hepatocellular carcinoma

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    Background & Aims: Tumour mutational burden (TMB) predicts improved response and survival to immunotherapy. In this pilot study, we optimized targeted next-generation sequencing (tNGS) to estimate TMB in hepatocellular carcinoma (HCC). Methods: We sequenced 48 non-paired samples (21 fresh-frozen [FF] and 27 paraffin-embedded [FFPE]), among which 11 FFPE samples were pretreated with uracil-DNA glycosylase (UDG). Thirty samples satisfied post-sequencing quality control. High/low TMB was defined by median number of mutations/Mb (Mut/Mb), across different minimum allele frequency (MAF) thresholds ( 650.05, 650.1 and 650.2). Results: Eligible patients (n\ua0=\ua029) were cirrhotic (84%) with TNM stage I-II HCC (75%). FFPE samples had higher TMB (median 958.39 vs 2.51 Mut/Mb, P\ua0\ua0T transitions at CpG sites (median 60.3% vs 9.1%, P\ua0=.002) compared to FF. UDG-treated samples had lower TMB (median 4019.92 vs 353 Mut/Mb, P\ua0=.041) and deamination counts (median 6393.5 vs 328.5, P\ua0=.041) vs untreated FFPE. At 0.2 MAF threshold with UDG treatment, median TMB was 5.48 (range 1.68-16.07) and did not correlate with salient pathologic features of HCC, including survival. Conclusion: While tNGS on fresh HCC samples appears to be the optimal source of tumour DNA, the low median TMB values observed may limit the role of TMB as a predictor of response to immunotherapy in HCC

    Structural characterization and mechanical properties of dextrin-graft-poly(butyl acrylate-co-styrene) copolymers

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    Dextrin/starch-graft-poly(butyl acrylate-co-styrene) copolymers have been synthesized by radical graft copolymerization and their structure and mechanical properties are reported. High molecular weight grafted chains formation is favored, leading to a low degree of substitution of starch hydroxyl groups. Wide-Angle-X-ray Scattering (WAXS) analysis indicates that all materials are amorphous and Transmission Electron Microscopy (TEM) investigations reveal a two-phase morphology. This is further confirmed by the presence of two glass transitions, one related to the starch/dextrin macromolecules and sensitive to water content, and one assigned to the grafted polymers that is composition dependent. Water uptake is controlled by dextrin/starch content but diffusivity increases with the butyl acrylate ratio. The mechanical behavior is dependent on monomer ratio, and water content. Increasing butyl acrylate ratio improves the ductility of the sample while materials become brittle as soon as styrene ratio is predominant in the grafted chains. While no effect of molecular weight of starch substrate on structure and thermal behavior is evidenced, dextrin-based materials are slightly more ductile than starchbased ones. The interest of using dextrin instead of starch is further highlighted by a lower viscosity of the reactive medium, together with an improved processability, as structural materials can be obtained over a wider range of composition than with native starch

    Applicability of routine targeted next-generation sequencing to estimate Tumor Mutational Burden (TMB) in patients treated with immune checkpoint inhibitor therapy.

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    It remains unclear whether targeted next-generation sequencing (tNGS) conveys a reliable estimate of tumor mutational burden (TMB). We sequenced 79 archival samples of immune checkpoint inhibitors (ICPIs) recipients (57% lung cancer, 43% melanoma) using Ion Ampliseq Cancer Hotspot Panel. Employing multiple cutoff values, we verified that TMB by tNGS did not correlate with response or survival following ICPI. We found enrichment of ATM mutations in ICPI-refractory tumors (P=0.01) to correlate with worse survival (4.2 vs. 10 mo, P=0.03). Limited-coverage tNGS delivers an imprecise estimate of patients' TMB but may aid identification of candidate somatic variants of predictive/prognostic significance

    New liberalism, new language? The use of collectivist concepts in the budget speeches of 1893–95 and 1906–14

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    The article considers the Budget Speeches of Asquith and Lloyd George during the period of the Liberal social reforms of 1906–14. It examines how these Budget speeches conceptualised the debate surrounding these reforms and discusses the extent to which this conceptualisation can be seen as reflecting the discursive character of a New Liberalism. The focus is on key collectivist concepts—“the state”, “the community”, “the people” and “the nation”. These were concepts which were very far from being the preserve of the Liberals but it is argued they were unpacked and used in ways that constituted a different conceptual terrain from that which had characterised previous Liberal budget speeches. The article considers the frequency of their usage but, more importantly, their collocation and rhetorical context and argues that these do indeed suggest that in important respects these budgets displayed a rhetorical character reflective of the ideology of New Liberalism
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