Chemiluminescence Activity Of Neutrophils Research Articles

Investigating the Response of Human Neutrophils to Hydrophilic and Hydrophobic Micro-Rough Titanium Surfaces.

Various treatments have been used to change both the topography and chemistry of titanium surfaces, aiming to enhance tissue response and reduce healing times of endosseous implants. Most studies to date focused on bone healing around dental implants occurring later during the healing cascade. However, the impact of the initial inflammatory response in the surgical wound site on the success and healing time of dental implants is crucial for implant integration and success, yet it is still poorly understood. The purpose of this study was to investigate the effect of titanium surface hydrophilicity on the response of human neutrophils by monitoring oxygen radical production, which was measured as chemiluminescence activity. Materials and Methods: Neutrophils were isolated from human donors’ blood buffy coats using the double sucrose gradient method. Neutrophils were exposed to both hydrophilic and hydrophobic titanium surfaces with identical topographies in the presence and absence of human serum. This resulted in six experimental groups including two different implant surfaces, with and without exposure to human serum, and two control groups including an active control with cells alone and a passive control with no cells. Two samples from each group were fixed and analyzed by SEM. Comparisons between surface treatments for differences in chemiluminescence values were performed using analysis of variance ANOVA. Results and Conclusion: In the absence of exposure to serum, there was no significant difference noted between the reaction of neutrophils to hydrophilic and hydrophobic surfaces. However, there was a significant reduction in the mean and active chemiluminescence activity of neutrophils to serum-coated hydrophilic titanium surfaces than to serum-coated hydrophobic titanium surfaces. This suggests that surface hydrophilicity promotes enhanced adsorption of serum proteins, which leads to decreased provocation of initial immune cells and reduction of local oxygen radical production during wound healing. This can help explain the faster osseointegration demonstrated by hydrophilic titanium implants.

Effect of physical exercise on cortisol concentration and neutrophil oxygen metabolism in peripheral blood of horses

Abstract The aim of the study was to evaluate the effect of regular physical exercise on cortisol concentration and oxygen-dependent bactericidal activity of neutrophils in peripheral blood in recreational and competitive sport horses (racehorses - Ra, trotters - T, jumping horses - J, driving horses - D). The study was conducted on 55 clinically healthy horses. Blood samples were collected from the external jugular vein three times: before exercise, immediately after exercise, and after 30-min rest. Blood samples were subjected to haematological examination, cortisol concentration was determined by radioimmunoassay (RIA) and neutrophil oxygen metabolism of neutrophils was determined using a chemiluminescence method. The analysis showed that cortisol concentration was significantly higher (P<0.05) post-exercise only in the blood of sport horses. This finding, along with a significant correlation (P<0.00005) with the heart and respiratory rates, suggests that the magnitude of cortisol secretion is associated with the intensity and duration of exercise. The relatively small post-exercise increase in cortisol concentration during different exercises of horses resulted in a transient increase of chemiluminescence activity of neutrophils, mainly in D (P<0.00001) and J horses (P<0.01). In the studied groups analysis of the correlation between cortisol concentration and other parameters showed significant correlation only in the case of the CL total in T (P<0.02) and D horses (P<0.004). It is therefore apparent that in a limited concentration, this hormone may stimulate the activity of these cells, although the effect of other neurohormonal factors cannot be excluded. This result confirms that regular and moderate training loads have a beneficial effect on the immunological status of horses.

CHARACTERISTICS NONSPECIFIC ELEMENT IMMUNITY IN PATIENTS WITH CHRONIC ATROPHIC GASTRITIS

Background: Investigate characteristics non-specific immunity in the blood in patients with chronic gastritis and chronic atrophic gastric. Materials and methods: The study involved 200 patients aged 25 to 65 who were in randomly into 3 groups. The first group included 100 healthy subjects in the second group – 85 patients with moderate atrophic gastritis, gastric body, the third group – 25 patients with severe atrophic gastritis of the body of the stomach. The study was conducted with the approval of the Ethics Committee FGBNU “Institute of Medical Problems of the North” (Acting Director – MD, professor Kasparov E.V.). Each participant signed an informed consent form for examination, according to the Declaration of Helsinki of the World Medical Association, which regulates conduct research. Diagnosis of atrophic gastritis performed by determining the pepsinogen-1, 2-pepsinogen and H. pylori antibodies in serum and morphological study of the gastric mucosa. Evaluation of non-specific immunity was conducted by studying the chemiluminescent activity of neutrophils (De sole p.et al.; 1983). Statistical analysis was performed using the application package Statistica 7.0 (StatSoft, USA). Results: violation of spontaneous and induced functional activity of neutrophils observed in all groups of patients with chronic gastritis, while in patients with chronic superficial gastritis revealed a reduction in both spontaneous and induced chemiluminescence activity of neutrophils. On the other side of the milestones of patients with chronic atrophic gastritis there is an increase of the functional activity of neutrophils expressed significantly more severe atrophic changes in the gastric mucosa. Considering that the main function of neutrophil granulocytes – phagocytosis of bacterial agents, modified own cells, their increased activity can be attributed to an infectious process in the gastric mucosa and harsh destruction of cells of the stomach due to atrophic changes. Conclusion: thus, with an increase in infectious load or atrophic changes in the mucosa of the stomach does not exclude the exhaustion of reserve capacity of phagocytes, their modification, thus the transformation of precancerous condition in cancer.

Maintenance and down-regulation of primed neutrophil chemiluminescence activity in human whole blood.

Priming of polymorphonuclear neutrophils (PMN) in whole blood (by tumor necrosis factor alpha and interleukin-8 for enhancement of luminol-dependent chemiluminescence induced by human complement-opsonized zymosan) was stable for 120 min. In contrast, priming of isolated PMN in plasma-free suspension for responses to opsonized zymosan, formyl-methionyl-leucyl-phenylalanine, and phorbol myristate acetate was markedly less stable. Decay of priming was not due to irreversible inactivation of the terminal CL production machinery because PMN could be reprimed by platelet-activating factor or leukotriene B4. The tumor necrosis factor-alpha-primed state of isolated PMN was stabilized by host plasma in a concentration-dependent fashion. We conclude that PMN priming results in a dynamic state that is reversible. Our findings suggest the existence of blood-borne components that may act to stabilize or modify PMN priming.

Visualization of oxidative processes at the cellular level during neutrophil-mediated cytotoxicity against a human hepatoma cell line, HCC-M.

Human neutrophil-mediated oxidative processes against a human hepatoma cell line, HCC-M, was visualized at the cellular level by using a silicon-intensified target camera and subsequently processing with a computer-assisted digital-imaging processor. Neutrophils were activated by a streptococcal preparation, OK-432. A hydroperoxide-sensitive tracer, dichlorofluorescein diacetate, was loaded in HCC-M and temporal and spatial changes of lipid peroxides in this cell after addition of stimulated neutrophils were analyzed. The luminol-dependent chemiluminescence activity of neutrophils was significantly enhanced and continued for at least 2 hr by stimulation with OK-432, and its activity was shown to be accumulated at the site where a neutrophil attached with HCC-M. The intensity of dichlorofluorescein fluorescence in HCC-M rapidly increased after adding stimulated neutrophils, and their reaction was significantly attenuated by superoxide dismutase. The number of non-viable cells was increased as the dichlorofluorescein fluorescence increase. It is suggested that oxidative stress may play an important role in neutrophil-mediated tumor-cell damage.

Enhanced Neutrophil Function in Children on Bromide Therapy

The final step in neutrophil bacterial killing is formation of a toxic halide complex. For this reason, we studied neutrophil function in children receiving bromide anticonvulsant therapy. Whole blood and serum were obtained from 7 patients with seizure disorders treated orally with triple bromide elixir to examine neutrophil function as measured by luminol enhanced chemiluminescence (CL). Serum bromide concentrations [Br-] were determined concomitantly. There was a direct correlation between [Br-] and CL activity of neutrophils (r = 0.87) with peak CL responses significantly higher than controls when [Br-] were in the therapeutic range (10-20 mM). With [Br-] above 25 mM, CL activity was reduced. Serum from patients also enhanced CL of control neutrophils with a similar relationship to measured [Br-]. To confirm that enhanced neutrophil activity was attributable to [Br-] use, [Br-] ranging from 0-50 mM were added to control neutrophils in otherwise normal physiologic conditions and the CL assay was performed. Results expressed as percent of control values were as follows: [Br-] 5 mM, 110%; 10 mM, 158%; 15 mM, 194%; 20 mM, 252%; 25 mM, 136%; 30 mM, 364%; and 50 mM, 205%. These data demonstrate that Br- enhances phagocytic and bactericidal activity of neutrophils and suggest that Br- therapy may augment host defense capabilities.

Bovine sire effects on daughters' in vitro blood neutrophil functions, lymphocyte blastogenesis, serum complement and conglutinin levels

Blood neutrophil functions, lymphocyte blastogenic responses, serum complement, and serum conglutinin activity of 98 lactating Holstein cows from two genetic lines were evaluated. The genetic lines were produced in a selection experiment that created and perpetuated genetic differences in milk production for up to seven generations. No significant differences between the two genetic lines of cows were found for neutrophil function, lymphocyte blastogenic responses, serum complement levels, or serum conglutinin levels. Significant differences between sire progeny groups within lines were found for unstimulated and mitogen-stimulated lymphocyte blastogenesis ( P<0.0001), and almost all neutrophil functions (antibody independent neutrophil cytotoxicity, antibody dependent neutrophil cytotoxicity, ingestion of bacteria, iodination, chemiluminescence, chemokinesis, and chemotaxis ( P≤0.05)). Sire progeny group differences ( P≤0.0001) within lines for serum complement and conglutinin activity were also found. Neutrophil chemiluminescence activity (positive relationship; P≤0.001), concanavalin A-stimulated lymphocyte blastogenesis (positivee relationship; P≤0.004), and serum conglutinin activity levels (negative relationship; P≤0.01) each had small but significant associations with the total milk somatic cell count. Cows seropositive for bovine leukosis virus had increased resting and mitogen-stimulated lymphocyte blastogenic activity and were associated with increased in vitro neutrophil random migration and production of superoxide anion. Estimates of genetic parameters of various immune cell functions, of serum complement and of conglutinin levels for daughters of 11 sires with 4–6 daughters in the data set were determined. In this report, genetic variation was demonstrated for nonspecific humoral and cellular immunity.

Role of PAF in ischemia-reperfusion injury in the rat stomach.

Ischemia-reperfusion induced extensive gastric mucosal injury and an increase in chemiluminescence activity of neutrophils obtained from the portal vein in hemorrhagic shock rats. CV-3988, a selective antagonist of platelet activating factor (PAF), significantly reduced the gross and histologic gastric damage, and the increase in chemiluminescence activity of neutrophils. These results suggest that PAF generated on hypoxia might stimulate oxygen radical production by neutrophils, resulting in the occurrence of gastric injury in hemorrhagic shock rats.