Osteocalcin-expressing endothelial progenitor cells and serum osteocalcin forms are independent biomarkers of coronary atherosclerotic disease severity in male and female patients.

PURPOSE: Osteocalcin (OC), an osteoblast-derived regulator of metabolic processes, and circulating early endothelial progenitor cells (EPC, CD34 - /CD133 + /KDR +) expressing OC (OC +) are potential candidates linking bone metabolism and the vasculature and might be involved in vascular atherosclerotic calcification. This study aimed at assessing the association of circulating levels of different OC forms and of EPCs count with disease severity in patients with documented coronary atherosclerosis (CAD). METHODS: Patients (n = 59) undergoing coronary angiography were divided, according to stenosis severity, into (1) early coronary atherosclerosis (ECA) (n = 22), and (2) late coronary atherosclerosis (LCA) (n = 37). Total OC (TOC), carboxylated OC (cOC), undercarboxylated OC (unOC) were quantified by ELISA. EPC OC + count was assessed by flow cytometry. RESULTS: EPC OC + counts showed significant differences between ECA and LCA groups. unOC and unOC/TOC ratio were inversely correlated with EPC OC + count. A significant decrease in TOC and unOC plasma levels was associated with higher cardiovascular risk factors (CVRFs) number. EPC OC + count was correlated with LDL-C, total cholesterol, and triglycerides, with a greater significance in the LCA group. No association between the different forms of circulating OC (TOC, ucOC, cOC) and severity of CAD was found. CONCLUSION: This study showed a significant association between EPCs (CD34 - /CD133 + /KDR + /OC +), CAD severity and CVRFs, suggesting an active role for EPC OC + in the development of CAD. An inverse correlation between TOC, ucOC, and number of CVRFs was observed, suggesting that OC, regardless of its carboxylation status, may be developed as a further cardiovascular risk biomarker.

Kidney transplantation decreases the level and procoagulant activity of circulating microparticles.

Microparticles (MP) are important players in cardiovascular disorders. Renal transplantation significantly improves the survival of hemodialyzed patients, in part because cardiovascular disease (CVD) progression is lessened. We hypothesized that the beneficial effect of renal transplantation on cardiovascular outcome might involve decreased levels of circulating MP. We evaluated the kinetics of MP subpopulations and their procoagulant activity (MP-PCA) in 52 patients before and 3, 6, 9 and 12 months after graft with reference to 50 healthy controls and we evaluated the impact of cardiovascular complications. During the follow-up, the increased levels of MP observed before graft were significantly decreased and reached normal values with different kinetics according to their cellular origin whereas MP-PCA remained significantly higher than in controls. From multivariate analysis, the levels of MP were negatively correlated with renal function. At 12 months, the decrease in MP and MP-PCA was more pronounced in patients without history of CVD than those with. In conclusion, we demonstrated that renal graft is associated with decreased levels of MP levels and MP-PCA, even more pronounced so in patients without history of CVD. Therefore, we suggest that MP lowering could be involved in the vascular dysfunction improvements reported after transplantation.

Impact of immunosuppressive treatment on endothelial biomarkers after kidney transplantation.

Endothelial dysfunction occurs in hemodialysis and kidney-transplanted patients and can be enhanced by immunosuppressive therapy. Circulating endothelial cells (CEC), endothelial microparticles (EMP) and sVCAM-1 provide information on endothelium activation and damage. We compared the impact of two immunosuppressive regimens (CsA/Aza vs. Tac/MMF) on the kinetics of CEC, EMP and sVCAM-1 levels in 52 patients, both before graft and 3, 6, 9 and 12 months after graft, in reference to 50 healthy controls. CEC, EMP and sVCAM-1 levels were significantly decreased 1 year after transplantation (M12) as compared to pretransplant values. At M12, CEC and sVCAM-1 levels were significantly higher than those of controls whereas EMP reached normal values. Nine months postgraft, lower CEC and normalized EMP levels were found in patients receiving cyclosporine microemulsion/ azathioprine (CsA/Aza) when compared to patients treated with tacrolimus/ mycophenolate mofetil (Tac/MMF). Multivariate analysis evidenced positive correlations between CEC and history of cardiovascular diseases and between EMP and cytomegalovirus infection at M12. In conclusion, our combined analysis of endothelial injury markers confirms the favorable impact of renal transplantation on endothelium, and show that CEC levels discriminate treatment-associated endothelial toxicity. These results enlighten the potential of these noninvasive blood biomarkers in indexing vascular injury and optimize therapeutic options.

CD146-based immunomagnetic enrichment followed by multiparameter flow cytometry: a new approach to counting circulating endothelial cells.

BACKGROUND: Circulating endothelial cells (CECs) have emerged as non-invasive biomarkers of vascular dysfunction. The most widely used method for their detection is CD146-based immunomagnetic separation (IMS). Although this approach has provided consensus values in both normal and pathologic situations, it remains tedious and requires a trained operator. OBJECTIVES: Our objective was to evaluate a new hybrid assay for CEC measurement using a combination of pre-enrichment of CD146+ circulating cells and multiparametric flow cytometry measurement (FCM). PATIENTS AND METHODS: CECs were determined in peripheral blood from 20 healthy volunteers, 12 patients undergoing coronary angioplasty, and 30 renal transplant recipients, and blood spiked with cultured endothelial cells. CD146+ cells were isolated using CD146-coated magnetic nanoparticles and labeled using CD45-fluorescein isothiocyanate and CD146-PE or isotype control antibody and propidium iodide before FCM. The same samples were also processed using CD146-based immunomagnetic separation as the reference method. RESULTS: The hybrid assay detected CECs, identified as CD45(dim)/CD146(bright)/propidium iodide(+), with high size-related scatter characteristics, and clearly discriminated these from CD45(bright)/CD146(dim) activated T lymphocytes. The method demonstrated both high recovery efficiency and good reproducibility. Both IMS and the hybrid assay similarly identified increased CEC levels in patients undergoing coronary angioplasty and renal transplantation, when compared to healthy controls. In patients, CEC values from these two methods were of the same order of magnitude and highly correlated. Bland-Altman analysis revealed poor statistical agreement between methods, flerrofluid-FCM providing higher values than IMS. CONCLUSION: This new hybrid FCM assay constitutes an accurate alternative to visual counting of CECs following CD146-based IMS.

Comparative study of flotation techniques for the treatment of liquid effluents.

This work aimed to study the performance of three different induced air flotation units (flotation column, flotation tank and centrifugal flotation in hydrocyclone) for the treatment of a synthetic dairy effluent. Under continuous operation, it was possible to achieve removal efficiencies of milky material in suspension up to 90%, both for the flotation column and the flotation tank units. Using the centrifugal flotation unit in hydrocyclone, it was possible to decrease up to 45% of all suspended material in the effluent, with a clarified flow rate approximately three times greater than those found for the previous flotation units. In the centrifugal flotation unit, better results were obtained for air flow rate-feed flow rate ratios (Q(air)/Q(L)) greater than 0.15, and for underflow-overflow ratios (Qu/Qo) lower than 1.0.

Recovery of Bacillus sphaericus 2362 spores from growth medium by flocculation/sedimentation.

Bacillus sphaericus 2362 spore sedimentation was evaluated through batch settling experiments, using tannin as the flocculating agent. The flocculation was demonstrated to be efficient up to the tannin concentration of 150 ppm. The floc diameter averaged 208 micro m, and its density was found to be 1.09 g/mL. The sedimentation process using tannin as a flocculating agent is promising, and a spore concentrate was obtained without loss of biological activity, presenting a LC(50) equal to 0.22 ppm. The result indicates that the larvicide activity is appropriate for controlling populations of Culex quinquefasciatus.

Flotation techniques for oily water treatment.

The aim of this work is to develop alternative techniques for the treatment of waters heavily contaminated by oil. Furthermore, the treatment system should achieve high removal efficiencies even under unfavorable conditions, when oil is finely dispersed in the water phase and oil droplet sizes range from 5-30 mm and concentrations are between 100 and 300 mg l(-1). The first experiments were carried out in an induced air flotation system where a flotation column performance was evaluated in batch and continuous operation. The second system investigated in this work focused on the association of centrifugal separation in a hydrocyclone and the flotation operation. The considered system is characterized by the association of these two processes, resulting the set-up in a compact unit (centrifugal flotation system). The bubbles generation and the droplet-bubble contact are performed through a gas-liquid ejector, while the separation of the phase rich in oil (froth phase) is promoted by a hydrocyclone. In both systems, it was possible to reduce the chemical demand of oxygen by more than 85% and the oil concentration of an emulsion containing droplets with sizes between 10 and 20 mm, using Polyacrilamide as destabilizing agent.

Influence of the flocculating agent in sedimentation and performance of a non flocculent strain of Zymomonas mobilis in the ethanol production process.

The influence of the flocculating agent was studied in the performance (measured by microbial growth and ethanol production) of a non flocculent strain of Zymomonas mobilis, as well as the potentiality of the sedimentation process in the separation of the biomass from the fermentation broth. Among the flocculating agents studied, it was verified that both tannin and the polyelectrolyte yielded good results with regard to cellular performance. However, with regard to sedimentation tannin is more adequate to be used in processes involving Zymomonas mobilis.