Vascular calcification (VC), is a common complication in patients with chronic kidney disease and increases mortality. Although oxidative stress is involved in the onset and progression of this disorder, the specific role of some main redox regulators such as catalase, the main scavenger of H2O2, remains unclear. In the present study, epigastric arteries of kidney transplant recipients, an in vivo model of VC and an in vitro model of VC exhibiting catalase overexpression (Cts) were analyzed. Peri-calcification areas of human epigastric arteries have increased levels of catalase and cytoplasmic rather than nuclear RUNX2. In the in vivo model, advanced aortic VC concurs with lower levels of the H2O2 scavenger, glutathione peroxidase 3 compared to controls. In an early model of calcification using vascular smooth muscle cells (VSMCs), Cts VSMCs showed the expected increase in RUNX2 total levels. However, Cts VMSC also exhibited lower percentage of the nucleus stained for RUNX2 in response to calcifying media. At this early model of VC we did not observe dysregulation of mitochondrial redox state, an increase in general redox state was observed in the cytoplasm. These in vivo and in vitro results highlight the complex role of antioxidant enzymes as catalase in the process of VC by regulation of RUNX2 location.

Current antibiograms cannot discern the particular effect of a specific antibiotic when the bacteria are incubated with a mixture of antibiotics. To prove that this task is achievable, Escherichia coli strains were treated with ciprofloxacin for 45 min, immobilized on a slide and stained with SYBR Gold. In susceptible strains, the nucleoid relative surface started to decrease near the MIC, being progressively condensed as dose increased. The shrinkage level correlated with the DNA fragmentation degree. Ciprofloxacin-resistant bacilli showed no change. Additionally, E. coli strains were incubated with ampicillin for 45 min and processed similarly. The ampicillin-susceptible strain revealed intercellular DNA fragments that increased with dose, unlike the resistant strain. Co-incubation with both antibiotics revealed that ampicillin did not modify the nucleoid condensation effect of ciprofloxacin, whereas the quinolone partially decreased the background of DNA fragments induced by ampicillin. Sixty clinical isolates, with different combinations of susceptibility-resistance to each antibiotic, were co-incubated with the EUCAST breakpoints of susceptibility of ciprofloxacin and ampicillin. The morphological assay correctly categorized all the strains for each antibiotic in 60 min, demonstrating the feasible independent evaluation of a mixture of quinolone and beta-lactam. The rapid phenotypic assay may shorten the incubation times and necessary microbial mass currently required for evaluation.