To assess in vivo effects of antioxidants on vascular cell adhesion molecule (VCAM)-1 expression, circulating soluble VCAM-1 and intraerythrocytic reduced glutathione (GSH) and GSH disulphide (GSSG) concentrations were evaluated in non-insulin-dependent diabetic patients without complications (9 men, 6 women, 48 +/- 6 years old) before and after 1 month of either oral N-acetyl-L-cysteine (1.200 mg/day) or placebo treatments, given in randomized, cross-over, double-blind fashion. Ten healthy subjects (7 men, 3 women, 52 +/- 4 years old) served as control subjects. Baseline plasma VCAM-1 concentrations were higher (p = 0.007) in non-insulin-dependent diabetic patients (707.9 +/- 52.5 ng/ml) than in control subjects (627.3 +/- 84.6 ng/ml). Intraerythrocytic GSSG content was higher (non-insulin dependent diabetic patients: 0.618 +/- 0.185 micromol/g Hb; control subjects: 0.352 +/- 0.04 micromol/g Hb, p = 0.0002), whereas intraerythrocytic GSH concentrations were lower (p = 0.001) in non-insulin dependent diabetic patients (6.0 +/- 0.7 micromol/g Hb) than in control subjects (7.1 +/- 0.5 micromol/g Hb). The mean GSH:GSSG ratio was also lower (p = 0.0001) in the first (10.9 +/- 4.5) than in the second group (20.2 +/- 1.4). Circulating VCAM-1 and intraerythrocytic GSH concentrations were negatively correlated in non-insulin diabetic patients (r = 0.605, p = 0.01). Treatment with N-acetyl-L-cysteine decreased plasma VCAM-1 (p = 0.01) and intraerythrocytic GSSG (p = 0.006) but increased GSH concentrations (p = 0.04) and the GSH:GSSG ratio (p = 0.004) in non-insulin dependent diabetic patients. Our data indicate that the vascular endothelium is activated in non-insulin dependent diabetes. Antioxidant treatment counterbalanced such endothelial activation. Thus, antioxidant agents might protect against oxidant-related upregulation of endothelial adhesion molecules and slow down the progression of vascular damage in non-insulin dependent diabetes.

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We studied the predictive value of the PaO2/FiO2 ratio for classifying COVID-19-positive patients who will develop severe clinical outcomes. One hundred fifty patients were recruited and categorized into two distinct populations (“A” and “B”), according to the indications given by the World Health Organization. Patients belonging the population “A” presented with mild disease not requiring oxygen support, whereas population “B” presented with a severe disease needing oxygen support. The AUC curve of PaO2/FiO2 in the discovery cohort was 0.838 (95% CI 0.771–0.908). The optimal cut-off value for distinguishing population “A” from the “B” one, calculated by Youden’s index, with sensitivity of 71.79% and specificity 85.25%, LR+4.866, LR−0.339, was < 274 mmHg. The AUC in the validation cohort of 170 patients overlapped the previous one, i.e., 0.826 (95% CI 0.760–0.891). PaO2/FiO2 ratio < 274 mmHg was a good predictive index test to forecast the development of a severe respiratory failure in SARS-CoV-2-infected patients. Moreover, our work highlights that PaO2/FiO2 ratio, compared to inflammatory scores (hs-CRP, NLR, PLR and LDH) indicated to be useful in clinical managements, results to be the most reliable parameter to identify patients who require closer respiratory monitoring and more aggressive supportive therapies. Clinical trial registration: Prognostic Score in COVID-19, prot. NCT04780373 https://clinicaltrials.gov/ct2/show/NCT04780373 (retrospectively registered).

Although hyperinsulinaemia is an independent risk factor for the development of atherosclerotic lesions [1], mechanisms underlying the atherogenetic actions of insulin are largely unclear. Recent studies have shown that insulin exerts various endothelial effects, such as an increase of endothelin-1 and nitric oxide production [2]. These findings are of particular relevance and suggest insulin might also exert other endothelial effects which, in turn, could trigger and maintain the atherogenetic process.In this context, vascular cell adhesion molecule(VCAM)-1 is an endothelial adhesin whose up regulation is the most important initiating event in atheroma formation [3]. In spite of this, whether or not insulin might influence VCAM-1 expression by the human vascular endothelium is notknown. Diabetologia (1999) Methods. Human vascular endothelial cells derived from umbilical cord veins were incubated with either insulin (from 10 ±6 to 10 ±9 mol/l) or tumour necrosis factor-a (5 ng/ml) for 6 to 24 h. Plasma soluble vascular cell adhesion molecule-1 concentrations were evaluated in 12 non-insulin-dependent diabetic patients (8 men, 4 women, mean age 47.1 ± 7.7 years) and 12 healthy volunteers matched for age, sex and weight (7 men, 5 women, mean age 42.2 ± 7.2 years) before and after a 2-h euglycaemic hyperinsulinaemic clamp. Results. Transcriptional activities of nuclear factor-kB luciferase and vascular adhesion molecule-1 luciferase statistically significantly increased after incubation with tumour necrosis factor-a. By contrast, a slight increment of nuclear factor-kB luciferase (mean: 1.8 ± 0.3 fold) but not of vascular cell adhesion molecule-1 luciferase transcriptional activities were detected in cells stimulated with insulin. Soluble vascular cell adhesion molecule-1 concentrations in cell supernatants increased after tumour necrosis factor-a but not insulin stimulation. In vivo, baseline plasma soluble vascular cell adhesion molecule-1 concentrations were higher (p = 0.03) in non-insulin-dependent patients (708.7 ± 97.4 mg/l) than controls (632.1 ± 65.2 mg/l) but were not related to fasting insulin concentrations and did not change during insulin infusion. Conclusion/interpretation. The increased concentrations of circulating soluble vascular cell adhesion molecule-1 indicates that the vascular endothelium is activated in non-insulin dependent diabetic patients. Our in vitro and in vivo findings show that vascular cell adhesion molecule-1 activation cannot be due to hyperinsulinaemia. [Diabetologia (1999