Oxidative burst measurement in patients treated with cytostatics: influence of G-CSF and role as a prognostic factor

Effect of acute isooxic hypercapnia on oxidative activity of systemic neutrophils in endotoxemic rabbits

Introduction

Whether carbon dioxide (CO₂) affects systemic oxidative phenomena under conditions of endotoxemia is not sufficiently clarified. The study aimed to assess the impact of moderate acute hypercapnia on the respiratory burst of circulating neutrophils in mechanically ventilated endotoxemic rabbits.

Material and methods

Twenty-four endotoxemic rabbits were mechanically ventilated with standard or CO₂-enriched gas mixture in order to obtain isooxic hypercapnia. At a baseline point and following 180 min of hypercapnic ventilation, luminol-dependent chemiluminescence (CL) of circulating neutrophils and serum 2-thiobarbituric acid reactive substance (TBARS) concentrations were measured. Throughout the study, leukocyte and neutrophil counts, pH status, circulatory parameters and body temperature were also assessed.

Results

Following 180 min of hypercapnic ventilation, opsonized zymosan (OZ)-stimulated neutrophils showed lower CL vs. the control group (p = 0.004). Other parameters studied were not affected.

Conclusions

Short-term isooxic hypercapnia in endotoxemic rabbits preserves circulating neutrophil count pattern and reactive oxygen species (ROS) generation, but it may reduce phagocytosis.

Distinct reconstitution of neutrophil functions after allogeneic peripheral blood stem cell transplantation

PURPOSE

The study investigated in detail neutrophil functions shortly after allogeneic peripheral blood stem cell transplantation (PBSCT).

METHODS

Different functions of neutrophils in 14 patients who received allogeneic PBSCT were investigated. The migratory capacity as well as the ability to induce oxidative burst following stimulation with either Phorbol-12-myristate-13-acetate (PMA), the chemotactic peptide N-formyl-Met-Leu-Phe (f-MLP) or opsonized Escherichia coli was analysed after engraftment (between day +30 and +40) and compared with the results obtained from healthy volunteers.

RESULTS

There are no differences in terms of the migratory capacity (P = 0.17), as well as regarding the oxidative burst after incubation with PMA (P = 0.08) or f-MLP (P = 0.06), compared with healthy men. In contrast, the capacity of neutrophils to induce oxidative burst following stimulation with E. coli is highly impaired (P = 0.0001) in patients shortly after engraftment.

CONCLUSION

The recovery of neutrophils after allogeneic PBSCT is not only influenced by the varying time of engraftment, but also represents a process that differs in distinct biological functions compared to normal granulopoieses.

Effects of Turkish pollen and propolis extracts on respiratory burst for K-562 cell lines

Bee-collected pollen and propolis are apicultural products which are composed of nutritionally valuable substances and contain considerable amounts of polyphenol substances which may act as potent antioxidants. We wanted to show if respiratory burst within a cancer cell lines could be influenced when incubated with pollen and propolis extracts or not. Pollen and propolis extracts at concentrations of 50, 25, 12.5 and 0 mg/ml were prepared by dimethyl sulfoxide (DMSO). K-562 cell cultures and mononuclear cell (MNC) cultures prepared from a peripheral blood sample to serve as control cells were incubated with extracts for 24 h. Determination of respiratory burst was carried out by intracellular dichlorofluorescein (DCFH) test by using flow-cytometric fluorescence analysis. While about 90% and 66% fluorescence was detected at zero concentrations for both K-562 and MNC cultures, fluorescence positivity decreased (between 3.8% and 11.8%) as concentrations of both propolis and pollen extracts increased for K-562 cell culture, but unchanged (between 20% and 83%) for MNC culture. It was concluded that pollen and propolis extracts inhibit respiratory burst within cancer cell lines probably by their antioxidant potentials.