Receptor-Coupled Phosphoinositide Hydrolysis in Human Retinal Pigment Epithelium

Carbachol and histamine stimulated phosphoinositide (PPI) hydrolysis in cultured human retinal pigment epithelium (RPE), as reflected by an accumulation of 3 H-inositol phosphates in the presence of 10 m M Li + . Carbachol increased PPI hydrolysis to greater than 600% of basal with an EC 50 of 60 Μ M ; stimulation was linear up to 60 min. This activation likely occurred via the M 3 muscarinic cholinergic receptor based on the IC 50 values for 4-diphenylacetoxy- N -methylpiperidine methiodide (0.47 n M ), pirenzepine (280 n M ), and 11-[[2-[(diethylamino)methyl]-1-piperidinyl]-acetyl]-5,11-dihydro-6 H -pyrido[2,3- b ][1,4]benzodiazepin-6-one (1.4 Μ M ). Carbachol-mediated PPI hydrolysis was decreased by 80% in the absence of extracellular Ca 2+ . Histamine stimulated PPI turnover in a linear manner by 180% with an EC 50 of 20 Μ M by the H 1 histaminergic receptor. Serotonin, glutamate, norepinephrine, and dopamine were inactive. In human RPE, the resting cytoplasmic Ca 2+ concentration, as determined by fura-2 fluorescence, was 138 ± 24 n M . On the addition of carbachol, there was a 180% increase in peak intracellular Ca 2+ ; addition of histamine increased intracellular Ca 2+ by 187%. These results suggest receptor-mediated, inositol lipid hydrolysis is coupled to intracellular Ca 2+ flux in human RPE.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66430/1/j.1471-4159.1991.tb03471.x.pd

Correction to: Tocilizumab for patients with COVID-19 pneumonia. The single-arm TOCIVID-19 prospective trial (Journal of Translational Medicine, (2020), 18, 1, (405), 10.1186/s12967-020-02573-9)

Following publication of the original article [1] the authors identified that the collaborators of the TOCIVID-19 investigators, Italy were only available in the supplementary file. The original article has been updated so that the collaborators are correctly acknowledged. For clarity, all collaborators are listed in this correction article

Tocilizumab for patients with COVID-19 pneumonia. The single-arm TOCIVID-19 prospective trial

BackgroundTocilizumab blocks pro-inflammatory activity of interleukin-6 (IL-6), involved in pathogenesis of pneumonia the most frequent cause of death in COVID-19 patients.MethodsA multicenter, single-arm, hypothesis-driven trial was planned, according to a phase 2 design, to study the effect of tocilizumab on lethality rates at 14 and 30 days (co-primary endpoints, a priori expected rates being 20 and 35%, respectively). A further prospective cohort of patients, consecutively enrolled after the first cohort was accomplished, was used as a secondary validation dataset. The two cohorts were evaluated jointly in an exploratory multivariable logistic regression model to assess prognostic variables on survival.ResultsIn the primary intention-to-treat (ITT) phase 2 population, 180/301 (59.8%) subjects received tocilizumab, and 67 deaths were observed overall. Lethality rates were equal to 18.4% (97.5% CI: 13.6-24.0, P=0.52) and 22.4% (97.5% CI: 17.2-28.3, P<0.001) at 14 and 30 days, respectively. Lethality rates were lower in the validation dataset, that included 920 patients. No signal of specific drug toxicity was reported. In the exploratory multivariable logistic regression analysis, older age and lower PaO2/FiO2 ratio negatively affected survival, while the concurrent use of steroids was associated with greater survival. A statistically significant interaction was found between tocilizumab and respiratory support, suggesting that tocilizumab might be more effective in patients not requiring mechanical respiratory support at baseline.ConclusionsTocilizumab reduced lethality rate at 30 days compared with null hypothesis, without significant toxicity. Possibly, this effect could be limited to patients not requiring mechanical respiratory support at baseline.Registration EudraCT (2020-001110-38); clinicaltrials.gov (NCT04317092)