Association of neutrophil chemiluminescence with microbicidal activity

Neutrophil function and cardiopulmonary bypass in humans. The effects of glucose and non-glucose containing bypass pump priming fluids

Defective polymorphonuclear neutrophil function during cardiopulmonary bypass (CPB) has been implicated as a cause of postoperative infection following open-heart surgery. Neutrophil function is known to be impaired in poorly controlled diabetics with elevations of blood glucose concentrations of the order which occur frequently during CPB when glucose containing priming fluids are used. Neutrophil function, as measured by bactericidal assay, and neutrophil and whole blood luminol dependent chemiluminescence, was studied in two groups of 1 2 patients undergoing coronary artery bypass graft surgery. Patients received either a glucose or non-glucose containing bypass pump-priming fluid. Postoperatively neutrophil luminol-dependent chemiluminescence was significantly increased in both groups (glucose prime groups p < 0.01, non-glucose prime group p < 0.01). Whole blood chemiluminescence was increased significantly intra and postoperatively in the glucose prime group ( p < 0.02, p < 0.02 respectively) but the increase was not significant in the non-glucose prime group. Bactericidal activity remained unchanged during and after surgery in both groups (mean bactericidal index intraoperatively 96.4 glucose group, 96.2 non-glucose group; postoperatively 99.7 glucose group, 99.7 non-glucose group). These data suggest that glucose containing bypass priming fluids do not modulate significantly the function of circulating neutrophils after CPB. Neutrophil function was not decreased after surgery, and other factors may be responsible for the reported higher incidence of bacterial infection after CPB.

Ultraweak photon emission as a non-invasive health assessment: a systematic review

We conducted a systematic review (SR) of the peer reviewed scientific literature on ultraweak photon emissions (UPE) from humans. The question was: Can ultraweak photon emissions from humans be used as a non-invasive health assessment? A systematic search was conducted across eight relevant databases: PubMed/MEDLINE, BIOSIS, CINAHL, PSYCHINFO, All of Cochrane EBM databases, GIDEON, DoD Biomedical Research, and clinicaltrials.gov from database inception to October 2011. Of the 1315 studies captured by the search strategy, 56 met the inclusion criteria, out of which 1 was a RCT, 27 were CCT, and 28 were observational and descriptive studies. There were no systematic reviews/meta-analyses that fit the inclusion criteria. In this report, the authors provide an assessment of the quality of the RCT included; describe the characteristics of all the included studies, the outcomes assessed, and the effectiveness of photon emission as a potential health assessment tool. This report demonstrates that the peer reviewed literature on UPE and human UPE measurement in particular is surprisingly large. Most of the human UPE literature is of good to high quality based on our systematic evaluation. However, an evaluation tool for systematically evaluating this type of "bio-evaluation" methodology is not currently available and would be worth developing. Publications in the peer reviewed literature over the last 50 years demonstrate that the use of "off-the-shelf" technologies and well described methodologies for the detection of human photon emissions are being used on a regular basis in medical and research settings. The overall quality of this literature is good and the use of this approach for determining inflammatory and oxidative states of patients indicate the growing use and value of this approach as both a medical and research tool.

Effects of bovine colostrum, foal serum immunoglobulin concentration and intravenous plasma transfusion on chemiluminescence response of foal neutrophils

The effects of bovine colostrum, absorption of equine colostral immunoglobulins and age on phagocytic and serum opsonizing activity of nine clinically healthy foals were examined. Cells and serum were collected prior to suckling and at 7, 14 and 28 days of age. Seven foals had serum IgG concentrations greater than 600 mg/dl whereas two foals had less than 350 mg of IgG/dl. Phagocytic and serum opsonic activity of eight clinically ill foals with less than 400 mg of IgG/dl of serum were also examined before and after plasma transfusion. Phagocytic and serum opsonizing activities were evaluated by an assay for chemiluminescence (CL) after addition of opsonized streptococci. Results showed that bovine colostrum stimulated CL of foal neutrophils. Preliminary characterization of opsonins in bovine colostrum by ammonium sulphate fractionating and heat inactivation indicated that opsonins generating CL were mainly associated with immunoglobulin G. Chemiluminescence generated by foal neutrophils varied with age with foal neutrophils collected at day 14 producing more CL than adult neutrophils (P less than 0.05). Foal serum opsonizing activity was similar to adult opsonizing activity if serum IgG concentrations were greater than 600 mg/dl but it was less if IgG concentration was less than 350 mg/dl (P less than 0.05). Chemiluminescence generated by foal and adult neutrophils was higher when post-transfusion foal serum was used as the source of opsonin than when pre-transfusion foal serum was used (P less than 0.05). When adult serum was the opsonin, chemiluminescence of foal neutrophils collected before and after plasma transfusion did not differ. The increase in CL following plasma transfusion was probably due to an increase in serum opsonizing activity.

Relationship between Transportation Stress and Polymorphonuclear Cell Functions of Bottlenose Dolphins, Tursiops truncatus

Dolphins in a captive environment are exposed to various kinds of stresses. Handling and transportation are stressful events for terrestrial mammals, and such stress may affect immune system function and increase susceptibility to infectious diseases. The same phenomenon could occur in dolphins, however, few studies have reported this in dolphins. The objective of this study was to evaluate the relationship between stress and polymorphonuclear (PMN) cell function of dolphins during transportation. Four bottlenose dolphins (Tursiops truncatus) were transported for 6 hr by truck. Serum cortisol levels, leukograms, phagocytosis, and superoxide production of PMN cells were evaluated during handling and transportation compared to resting values. The mean serum cortisol level was significantly increased during handling and transportation (p<0.05) when compared with the resting values. White blood cell (WBC) counts, eosinophil counts, phagocytosis, and superoxide production of PMN cells during handling and transportation stages decreased significantly in comparison with the resting stage (p<0.05). The concentration of serum cortisol was significantly correlated with the results of the WBC counts, eosinophil counts, superoxide production, and phagocytosis (p<0.01, p<0.05, p<0.05, and p<0.001, respectively). The present results indicate that handling and transportation are stressful events for dolphins and could affect their PMN cell functions, thereby leading to the impairment of the immune system.

Neutrophil function in neonates born to gestational diabetic mothers

OBJECTIVE

To examine neutrophil functional activity in the cord blood of term neonates born to gestational diabetic mothers, in association with the type of diabetes and the development of neonatal hypoglycemia.

METHODS

Neutrophil chemotaxis, random motility, and chemiluminescence was evaluated in the cord blood of 30 healthy term neonates: 12 were born to gestational diabetic mothers who received no-insulin (GDM-NI), eight to gestational diabetic mothers who received insulin (GDM), and 10 to mothers without diabetes (neonatal controls). In addition, the neutrophil functional activity in the peripheral venous blood of 10 healthy adults was analyzed.

RESULTS

Neutrophil functional activity in the cord blood of the neonates with and without maternal gestational diabetes was significantly lower than that in adults. As compared to neonatal controls, neonates born to both groups of GDM had decreased chemotaxis, random motility, and chemiluminescence (GDM-NI: 52.8+/-2.1 microm, p<0.001, 42.1+/-4.4 microm, p<0.001, and 140.1+/-6.9 counts per minute (cpm) x 10(3), p<0.01, respectively, and GDM: 53.0+/-1.9 microm, p<0.01, 41.8+/-4.0 microm, p<0.001, and 143.0+/-6.8 cpm x 10(3), p<0.01, respectively). Unlike controls, a tight correlation was identified between the tested neutrophil parameters in the cord blood of neonates born to diabetic mothers (r=0.70 to 0.91). The prevalence of hypoglycemia after birth was almost equal (50.0 to 41.7%) in the two groups of neonates born to diabetic mothers. There were differences in the neutrophil functional activity in the cord blood of the neonates with and without hypoglycemia.

CONCLUSION

Maternal gestational diabetes leads to impairment of cord blood neutrophil motility and postphagocytic bactericidal capacity independently from the insulin requirements for the maintenance of normoglycemia during pregnancy.

Effect of Intramammary Injection of RbIL-8 on Milk Levels of Somatic Cell Count, Chemiluminescence Activity and Shedding Patterns of Total Bacteria and S. aureus in Holstein Cows with Naturally Infected-subclinical Mastitis

Summary The effect of intramammary injection of recombinant bovine interleukin-8 (rbIL-8, 1 mg/10 ml of saline) on quarter milk levels of somatic cell count (SCC), chemiluminescence (CL) activity and counts of total bacteria and Staphylococcus aureus (S. aureus) was investigated, using 10 Holstein cows with an early stage or a late stage of subclinical mastitis naturally infected with S. aureus. In the late-stage group, milk SCC and CL activity had significant rises with maximum levels at 6 h, following maintained high levels thereafter post-cytokine injection. The counts in milk total bacteria and S. aureus were insignificantly decreased, being increased back on day 7 post-cytokine injection. Thus, the cytokine was inefficient for the late-stage subclinical mastitis. However, in the early-stage group milk SCC and CL activity declined to under pre-injection levels on day 7 after marked and significant rises at 6 h and day 1 post-cytokine injection. The milk total bacterial count decreased significantly on days 0.25 and 2. Furthermore, the milk S. aureus count was decreased significantly on days 1, 2, 3 and 7 by the cytokine injection. These results suggest that the rbIL-8 has a potential as a therapeutic agent of the subclinical mastitis of dairy cows, if the cytokine is applied at an initial stage of infection.

Evasion of cellular ocular defenses by contact lens isolates of Serratia marcescens

PURPOSE

Contact lens contamination by Serratia marcescens can lead to the development of microbial keratitis and contact lens-induced acute red eye, particularly during overnight contact lens wear. The aim of this study was to investigate the interaction of S. marcescens with polymorphonuclear leukocytes (PMNs), which occur in closed-eye tears.

METHODS

The respiratory burst of PMNs, when incubated with S. marcescens, was measured using chemiluminescence. Phagocytosis of planktonic and biofilm-grown bacteria by PMNs was also determined.

RESULTS

Some strains of S. marcescens did not induce a respiratory burst from PMNs and resisted phagocytosis regardless of opsonization. Phagocytic resistance and growth in the presence of PMNs was markedly increased when bacteria were grown as a biofilm on a contact lens.

CONCLUSIONS

The ability of S. marcescens to resist phagocytosis and grow to high levels in the presence of PMNs, particularly when grown as a biofilm on contact lenses, may be a mechanism by which this bacterium can survive the ocular host defense system, grow, and cause keratitis or other adverse responses.

Relationships between tissue contaminants and defense-related characteristics of oysters (Crassostrea virginica) from five Florida bays

Evidence linking bivalve defense responses with pollutant exposure is increasing. Contaminant effects on immune or defense responses could influence the ability of an organism to resist infectious disease. This study explored relationships between xenobiotic chemicals accumulated in oyster (Crassostrea virginica) tissue and various measures of putative oyster internal defense activities and physiological condition. Defense-related and physiological measurements were made on individual oysters collected from 22 sites at five Florida bays and pooled oyster tissue from each site was analyzed for polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), metals and certain pesticides. Chemical concentrations, physiological condition, and hemocyte and hemolymph characteristics varied across bays and among sites within a bay. Within-bay comparisons showed that sites with high oyster defense-related activities often had accompanying high tissue concentrations of one or more classes of xenobiotic chemicals. Correlation analysis performed across bays demonstrated significant positive relationships between most defense-related characteristics and at least one contaminant, including various PAH, PCB and trace metal analytes. In combination with other recent studies, these results strengthen the hypothesis that certain xenobiotic chemicals may be associated with elevated oyster hemocyte activities, even though the ultimate influence on disease resistance remains unknown.

Glucocorticosteroids and in vitro effects on chemiluminescence of isolated bovine blood granulocytes

The effects of glucocorticosteroids on respiratory burst of bovine granulocytes were studied in vitro by means of (1) chemiluminescence (luminol-dependent, phorbol 12-myristate 13-acetate (PMA)-stimulated), (2) a cell-free chemiluminescence assay, and (3) a myeloperoxidase assay. Significant effects on cellular chemiluminescence were only observed at the highest, not obtainable in vivo, concentration for all drugs except betamethasone. Prednisolone induced inhibition at therapeutic doses. Also, flumethasone and dexamethasone induced significant inhibition at lower concentrations. In the cell-free assay, all glucocorticosteroids, except betamethasone, inhibited chemiluminescence at high concentrations. None of the glucocorticosteroids tested affected myeloperoxidase activity. The results indicated that the drugs do not affect NADPH-oxidase activity. The adverse effects may be due to scavenging of free oxygen radicals, or to interference with the interaction between luminol and the myeloperoxidase-H2O2-halide system. It can be concluded that most glucocorticosteroids show no adverse effects on the respiratory burst of bovine granulocytes in vitro at therapeutical concentrations.

A low concentration of ethanol reduces the chemiluminescence of human granulocytes and monocytes but not the tumor necrosis factor alpha production by monocytes after endotoxin stimulation

The ability of polymorphonuclear neutrophils (PMNs) and monocytes (Mphi) to produce reactive oxygen species (ROS) has been related closely to their potential in the killing of microorganisms. Ethanol has been shown to impair the generation of ROS in these phagocytes after stimulation with some immunogens and to increase the susceptibility of alcohol abusers to infectious diseases. As endotoxemia is common in alcohol abusers, we investigated the effect of ethanol (21.7 mmol/liter) on the luminol-amplified chemiluminescence of PMNs and Mphi after endotoxin stimulation and the release of tumor necrosis factor alpha (TNF-alpha) from Mphi. Further, the efficiency of ethanol to inactivate chemically generated ROS was tested. Significant stimulation of ROS release occurred at endotoxin concentrations of 1 ng/ml or higher in both PMNs and Mphi. Ethanol significantly suppressed the formation of ROS in both cell types, the decrease being more pronounced in Mphi (-73. 8%) than in PMNs (-45.7%). The correlations between endotoxin concentration and the amount of released ROS showed a dose-dependent, sigmoidal course. Concentrations of endotoxin necessary for half-maximum stimulation were nearly identical (6 to 8 ng/ml) in both PMNs and Mphi, independent of the presence of ethanol. In contrast to ROS formation, ethanol had no effect on the amount of TNF-alpha produced by endotoxin-stimulated Mphi. Ethanol was shown to be unable to decrease the levels of chemically generated ROS under physiological conditions. Therefore, ethanol cannot be assumed to be an "antioxidative" compound but rather seems to modify processes of endotoxin recognition, intracellular signal transduction, or metabolism.

Modulation of Crassostrea virginica hemocyte reactive oxygen species production by Listonella anguillarum

Luminol- and lucigenin-augmented chemiluminescence (CL) were used to evaluate the ability of Listonella (formerly Vibrio) anguillarum to stimulate the production of reactive oxygen species (ROS) by Crassostrea virginica hemocytes. Whereas heat-killed L. anguillarum stimulated hemocyte CL in the lucigenin system, viable L. anguillarum did not. Neither viable nor heat-killed bacteria stimulated hemocyte production of luminol CL. Metabolically active L. anguillarum generated ROS, as indicated by luminol and lucigenin CL. It is proposed that bacterial catalase suppressed hemocyte-derived luminol CL. L. anguillarum, which possesses the antioxidant enzyme catalase, suppressed luminol CL generated by zymosan-stimulated hemocytes. Conversely, the catalase negative bacterium Carnobacterium piscicola had no effect on hemocyte-derived luminol CL elicited by zymosan. The inability of viable L. anguillarum to stimulate hemocyte ROS production, as measured by CL, does not support the proposed role for ROS in hemocyte-mediated bactericidal activity.

Effect of transportation on lower respiratory tract contamination and peripheral blood neutrophil function

OBJECTIVE

To evaluate the effect of transportation on lower respiratory tract contamination and peripheral blood neutrophil function in horses and to compare results from transported horses with those obtained in earlier experiments from horses confined with heads elevated.

DESIGN

A prospective study.

PROCEDURE

Six horses were transported by road for 12 h. Clinical and haematological examination, transtracheal aspiration and cell function studies were conducted before and after transportation. Results obtained after transportation were compared to pre-transportation values.

RESULTS

After transportation, peripheral blood leucocyte and neutrophil numbers were increased and rectal temperatures were evaluated. Transtracheal aspirates showed an accumulation of purulent respiratory tract secretions with increased numbers of bacteria, particularly beta-haemolytic Streptococcus spp and members of the Pasteurellaceae family. Three horses also had increased numbers of bacteria from the Enterobacteriaceae family relative to corresponding samples from earlier studies. Phagocytosis by peripheral blood neutrophils was significantly reduced, while the oxidative burst activity of peripheral blood leucocytes was either unchanged or enhanced.

CLINICAL IMPLICATIONS

Bacterial contamination of the lower respiratory tract occurs as a routine consequence of transportation of horses and is likely to be an important determinant in the development of transport-associated respiratory disease. Inflammatory airway secretions and increased numbers of bacteria were rapidly cleared, without clinical evidence of significant pulmonary disease and without additional treatment, in normal horses that were allowed to lower their heads after transportation. Peripheral blood neutrophilia and a reduction in neutrophil phagocytic function were evident for at least 36 h after transportation, suggesting that horses may require a number of days to recover from the stress of transportation. As the potential role of bacteria from the Enterobacteriaceae family in the development of transport-associated respiratory disease has not been elucidated, horses which develop clinical disease following transportation should undergo thorough bacteriological investigation to ensure appropriate treatment.

Suppressive effect of bronchoalveolar lavage fluid from pigs infected with Mycoplasma hyopneumoniae on chemiluminescence of porcine peripheral neutrophils

Bronchoalveolar lavage fluid (BALF) from pigs experimentally infected with Mycoplasma hyopneumoniae suppressed the chemiluminescence (CL) response of porcine polymorphonuclear neutrophils (PMN). The suppressive effect was significantly correlated with the concentration of prostaglandin E2 (PGE2) in the BALF. Furthermore, purified human PGE2 suppressed the CL response of porcine PMN. The increased level of PGE2 following infection with M. hyopneumoniae may be responsible for the suppression of PMN function in the airway of infected pigs. The decrease of PMN function may be responsible for exacerbation of mycoplasmal pneumonia by secondary infection with pulmonary bacterial pathogens.

Immune function early in acute pancreatitis

Circulating lymphocyte numbers and activation together with granulocyte function were measured in 20 patients in the early stages of an attack of acute pancreatitis and in 20 healthy controls. Circulating lymphocytes, T lymphocytes, and CD4 and CD8 T lymphocyte subsets were decreased in both mild pancreatitis (67-80 per cent of controls) and severe pancreatitis (22-40 per cent of controls). CD4:CD8 ratios were unchanged and median (interquartile range) interleukin 2 receptor expression was increased from less than 1 per cent in controls to 14(6) per cent in severe pancreatitis, suggesting lymphocyte activation. Median granulocyte chemiluminescence was increased to 293 per cent of controls in severe pancreatitis and random motility was reduced to 77 per cent of controls, indicating increased metabolic activity. Complement-mediated antibody-independent opsonization and chemotaxis toward endotoxin were normal. Immune function is not reduced early in acute pancreatitis. Granulocyte hyperactivity may be important in the development of multiple organ failure.

Suppression of chemiluminescence of eastern oyster (Crassostrea virginica) hemocytes by the protozoan parasite Perkinsus marinus

Experiments were conducted to determine the ability of the protistan parasite, Perkinsus marinus, to inhibit chemiluminescence of hemocytes from the eastern oyster, Crassostrea virginica. Luminol-enhanced chemiluminescence (CL) was used to measure the production of reactive oxygen intermediates (ROI) generated by oyster hemocytes using zymosan as a stimulant. To determine whether P. marinus suppresses ROI evoked from zymosan-stimulated hemocytes, live or heat killed P. marinus in filtered estuarine water (YRW) (salinity = 20 ppt) were added to (1) zymosan-stimulated hemocytes after CL reached its peak, or (2) hemocytes at the same time as zymosan, and reduction of CL responses were recorded. In both tests, controls received only estuarine water. Live P. marinus meronts significantly suppressed ROI production by zymosan-stimulated hemocytes. The suppression of ROI production was dose dependent. Suppression of ROI production from zymosan-stimulated hemocytes by heat killed P. marinus was significantly less than by live P. marinus. Similarly, CL of hemocytes was reduced, though not significantly when hemocytes were exposed to YRW preincubated with P. marinus. When P. marinus meronts were used as a stimulant, no CL response was elicited. Results of this study suggest that P. marinus cells are able to suppress ROI release from oyster hemocytes, thus evading this component of the host's defense.

Comparison of the in vitro effects of several cephalosporins on the oxidative burst of human phagocytes

The metabolic activity (oxygen radical formation) of human phagocytes was not substantially affected by the tested cephalosporins. Therapeutic concentrations caused only a mild suppression or immunopotentiation in some cases or there were no effects altogether.

Loss of neutrophil and natural killer cell function following feline immunodeficiency virus infection

Experimental infection with the Mt. Airy isolate of feline immunodeficiency virus (FIVMA), a lentivirus isolated from a domestic cat exhibiting signs of an immunodeficiency-like syndrome, results in transient lymphadenopathy, fever, stomatitis, enteritis, neurologic abnormalities, and immunosuppression. The effects of FIVMA infection on neutrophil and natural killer cell (NK) function were examined in vitro. Suppression of neutrophil chemiluminescence (CL) responses, as well as reduction in NK-mediated cytotoxicity were demonstrated. Neutrophil CL was decreased by 50% in infected cats when compared to control values. This loss of CL was present through 6 months after infection. In addition, NK-mediated cytotoxicity was approximately 50% less in FIVMA infected cats than in controls. Loss of innate immunity was paralleled with inversion in feline CD4/CD8 lymphocyte ratios and decreases in lymphocyte mitogenesis seen as early as 5 weeks after infection. These results suggest that FIVMA infection induces an immunodeficiency disorder in infected cats similar to that seen in human immunodeficiency virus infections.

Influence of involution on intramammary phagocytic defense mechanisms

Mammary secretions (n = 34 cows) and mammary phagocytes (n = 18 cows) were collected throughout the nonlactating (dry) period to determine changes in intramammary phagocytic defense mechanisms. Mammary secretions were evaluated for their ability to support phagocytosis of Staphylococcus aureus by neutrophils from donor cows and mammary phagocytes for phagocytic and chemiluminescence activity. Ability of secretions to support phagocytosis decreased with advancing length of the dry period. This effect was more pronounced when dry cow secretions constituted 50% of the phagocytic mixture. Phagocytic activity of mammary phagocytes decreased with advancing dry period when autologous secretion was used in the incubation mixture. With homologous secretion, the percentage of phagocytosis increased 5 to 6 d after drying off compared with before drying off and then gradually decreased throughout the remainder of the dry period. Chemiluminescence activity (log10 counts per minute) of mammary phagocytes was lower during the dry period and decreased with advancing dry period. Results indicated diminishing ability of secretions to support phagocytosis and diminished phagocytic and bactericidal mechanisms during the dry period.

Mechanism of inhibitory action of ketone bodies on the production of reactive oxygen intermediates (ROIS) by polymorphonuclear leukocytes

We determined an effect of acetoacetic acid (AcAc) and 3-hydroxybutyrate (3-OHB) on the production of reactive oxygen intermediates (ROIs) in polymorphonuclear leukocytes from healthy volunteers. Both AcAc and 3-OHB inhibited the luminol-dependent chemiluminescence (LDCL) activities assessed with initial slope and the inhibition rates were about 42%, 44% respectively by AcAc and 3-OHB when the leukocytes were preincubated with 10 mM AcAc or 3-OHB for 60 minutes. The LDCL activity was reduced by 16% and 42% following the addition of 1mM and 10 mM AcAc. The similar reduction of the LDCL activity was observed in the addition of 3-OHB. Either 3-OHB or AcAc failed to show a significant reduction of myeloperoxidase (MPO) activity. However, both 3-OHB and AcAc dose-dependently inhibited superoxide anion (O2-) production, measured by using cytochrome c. These data provided evidence that both 3-OHB and AcAc suppress neutrophil oxidative metabolism with respect with O2- production.

Adherence to bovine neutrophils and suppression of neutrophil chemiluminescence by Mycoplasma bovis

The adherence of viable and heat-treated Mycoplasma bovis to bovine peripheral blood neutrophils was studied by specific immunofluorescence staining and flow cytometry. Viable and heat-treated M. bovis cells, adhered to bovine neutrophils in dose-dependent fashion within a 30 min incubation. Fluorescence quenching using crystal violet indicated that unopsonized M. bovis cells remained on the surface of bovine neutrophils without experiencing significant ingestion. The effect of M. bovis adherence on neutrophil microbicidal function was examined by measuring luminol enhanced chemiluminescence (CL). Adherent M. bovis cells did not elicit a bovine neutrophil CL response over a 75 min incubation period. M. bovis inhibited the capacity of bovine neutrophils to mount a CL response. Inhibition occurred whether viable or heat-treated M. bovis cells were used and it occurred when neutrophils were stimulated with opsonized zymosan (OZ) or phorbol myristate acetate (PMA). Inhibition of the PMA stimulated neutrophil CL response required cytadherence by M. bovis cells. These findings suggest that activation of the bovine neutrophil respiratory burst was inhibited at or distal in the pathway to the activation of protein kinase C (PKC), the site of PMA stimulation, and that it was mediated by a direct interaction between the adhering M. bovis cells and the bovine neutrophil membrane.

Phagocytosis of mastitis isolates of Staphylococcus aureus and expression of type 5 capsular polysaccharide are influenced by growth in the presence of milk

Phagocytosis by bovine polymorphonuclear granulocytes of seven capsular polysaccharide type 5 Staphylococcus aureus strains isolated from mastitis [corrected] was investigated by means of luminol-dependent chemiluminescence. Bacteria were grown on four different agar media (brain heart infusion, Columbia broth, modified staphylococcus medium 110, and skim milk) and were opsonized by normal bovine serum. When compared to growth on brain heart infusion agar, Columbia agar, and modified staphylococcus medium 110 agar, growth on skim milk agar rendered five of the strains more resistant to opsonization. The other two strains were resistant in all culture media used. Short periods of incubation in milk after growth on brain heart infusion agar did not augment resistance to phagocytosis, indicating that mere adsorption of milk components on bacteria was not responsible. The variability of the chemiluminescence response of polymorphonuclear leukocytes was pronounced among strains with each growth medium except milk. Growth on modified staphylococcus medium 110 and on milk agar favored the masking of teichoic acid, as shown by inagglutinability with rabbit antiserum. Interestingly, agglutination by a monoclonal antibody to capsular polysaccharide type 5 was optimal when bacteria were grown on skim milk agar. This suggests that capsular polysaccharide participated in the masking effect. These findings indicate that masking of the bacterial target of most of the naturally acquired opsonins present in normal bovine serum occurred when bacteria grew in the presence of milk, resulting in an increased resistance to phagocytosis by polymorphonuclear leukocytes.

Inhibition of phorbol ester-induced neutrophil chemiluminescence by FeLV

Receptor-mediated activation is accompanied by phospholipid metabolism and by calcium fluctuation resulting in a chemiluminescence (CL) response in the neutrophil. This pathway involves activation of protein kinase C (PKC) and the NADPH oxidase. Artificial stimulants such as phorbol esters, specifically 12-O-tetradecanylphorbol-13-acetate (TPA), circumvent the receptor-mediated pathway and activate PKC resulting in a measurable CL response. Neutrophils from feline leukemia virus (FeLV) exposed cats were tested for their ability to generate a TPA-induced CL response. As compared to the non-FeLV-exposed specific-pathogen-free (SPF) control cat neutrophil CL responses, both viremic and nonviremic FeLV-exposed cats showed significant decreases in their CL responsiveness. Neither ultraviolet light-inactivated FeLV (UV-FeLV) nor protein components (FeLV-p15E and FeLV-p27) caused a significant decrease in the CL responses of the SPF cat neutrophils. The suppressed TPA-induced CL response from FeLV-infected cats may involve an intracellular mechanism not affected in vitro by exposure of the neutrophil to the virus or viral components.

Effect of an intravenous gammaglobulin preparation on the opsonophagocytic activity of preterm serum against coagulase-negative staphylococci

Recent reports have described cases of septicaemia caused by coagulase-negative staphylococci in preterm neonates, mainly due to the use of artificial intravenous devices. It was of interest to examine if intravenous immunoglobulin therapy, known to be effective in group B streptococcal infections of neonates, had a similar beneficial effect in coagulase-negative staphylococcal infections. Opsonophagocytosis of coagulase-negative staphylococci by normal polymorphonuclear leukocytes in the presence of cord blood serum supplemented with the commercial IgG preparation 'Sandoglobulin' was investigated, using luminol-dependent chemiluminescence. It was found that with two different coagulase-negative staphylococcal strains, Sandoglobulin had a concentration-dependent enhancing effect on the chemiluminescent response. This effect was demonstrated in the presence of native as well as inactivated cord blood serum and in the presence of sera from preterm infants (28-33 weeks). It is concluded that intravenous Sandoglobulin therapy may be effective in the treatment of preterm infants with severe coagulase-negative staphylococcal infections.

Postburn suppression of murine lymphocyte and neutrophil functions is not reversed by prostaglandin blockade

Certain arachidonic acid metabolites, including prostaglandins (PGs) E1 and E2, have been shown to exert marked immunosuppressive effects on T-cell and macrophage functions. Cyclooxygenase blockade with indomethacin or ibuprofen may ameloriate these effects. In the current study we measured lymphocyte proliferation by thymidine incorporation, the presence of T-cell activation antigens with monoclonal antibodies and two-color flow cytometry, and neutrophil (PMN) oxidative burst using a fluorescent marker, in control mice and in burned mice treated with indomethacin for 10 days after injury. One-half of the cell cultures were treated with indomethacin in vitro to ensure its continued presence during stimulation. Separate groups of mice were fed a fish oil-based diet which leads to the production of PGE3 rather than PGE2, versus standard mouse chow, a soy-bean oil-based diet which leads to PGE2 production. Lymphocyte proliferation, expression of T-cell activation antigens, and PMN oxidative burst remained depressed in burned mice treated with indomethacin in vivo (plus in vitro) and in those which received the fish oil-based diet, compared to control. Blockade of PG synthesis after murine burn injury by cyclooxygenase inhibition or alterations in the diet failed to restore T-lymphocyte activation or proliferation or to improve PMN oxidative burst. These data suggest that PGE2 alone does not explain the immunosuppression noted after burn injury.

Intravenous fat emulsion acutely suppresses neutrophil chemiluminescence

The immediate effect of intravenous fat emulsion on neutrophil oxidant release was studied. Opsonized nonencapsulated S. aureus was used to stimulate neutrophil activity. Luminol enhanced chemiluminescence was followed over 15 min and recorded as peak output (P; mV), integral under the curve (I; V-sec) and rate of increase (R; mV/sec). Eighteen chronically ill patients receiving glucose based total parenteral nutrition were studied before and after a 4- to 6-hr test infusion of 500 ml of 10% fat emulsion. P decreased from 719 +/- 46 to 461 +/- 42 mV (p less than 0.001), I decreased from 169 +/- 17 to 111 +/- 12 V-sec (p less than 0.001) and R decreased from 6.9 +/- 1.0 to 4.0 +/- 0.6 mV/sec (p less than 0.001). Preincubation of normal whole blood with fat emulsion in vitro did not adversely affect chemiluminescence (11 studies), nor did incubation of normal neutrophils with patient postinfusion plasma (10 studies). We conclude that fat emulsion infusion acutely suppresses neutrophil chemiluminescence. The suppression is not a direct effect of the fat emulsion per se and is not due to inhibitory substances in the plasma following infusion.

The in vitro effect of sulbactam on polymorphonuclear leukocyte function

The effects of sulbactam on polymorphonuclear leukocyte (PMN) chemotaxis, respiratory burst, and microbicidal activity against Staphylococcus aureus were evaluated in vitro. PMNs from normal adult volunteers were incubated with 0.5, 2, 5, 10, and 20 micrograms/ml of sulbactam for 30 min each. At concentrations of 5 and 10 micrograms/ml, sulbactam was found to enhance PMN bactericidal activity. No inhibitory effects on PMN function were noted at the concentrations of sulbactam that were tested. In addition, the in vitro inhibitory effect of ampicillin on PMN chemiluminescence was partially abrogated by the presence of sulbactam. These findings suggest that the microbicidal phagocytic response of human PMNs against S. aureus may be improved in vitro using concentrations of sulbactam that may be readily achieved with therapeutic doses of sulbactam/ampicillin.

FeLV-induced immunosuppression through alterations in signal transduction: down regulation of protein kinase C

Activation of protein kinase C by a phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA), was shown to stimulate the respiratory burst in normal cat neutrophils. Neutrophils from feline leukemia virus (FeLV)-exposed viremic and nonviremic cats had significant suppression of their respiratory burst when stimulated with TPA. The addition of whole ultraviolet light-inactivated FeLV and FeLV proteins to normal cat neutrophils produced no significant suppression of the respiratory burst. These data suggest two possible mechanisms for suppression. The first is partially due to viral alterations of the neutrophil as seen in viremic cats, but, because exogenously applied FeLV or FeLV proteins had no effect on the respiratory burst, an additional mechanism is present. The second mechanism may be caused by a latent FeLV infection residing in nonviremic cat bone marrows which alters their immune system, resulting in immunosuppression.

Effects of thiopental on granulocyte oxidative microbicidal capacity

Some anaesthetics are known to depress granulocyte chemiluminescence responses in the phagocytosis of zymosan as a measure of their oxidative microbicidal capacity. In this study the effects of thiopental were measured on chemiluminescence responses in the phagocytosis of Staphylococcus aureus and Escherichia coli, which are the commonest bacteria causing postoperative infections. Granulocytes from 14 healthy volunteers (mean age 35 +/- 9 (s.d.) years) were tested in vitro in the presence of clinical thiopental concentrations 0, 5, 10 and 25 micrograms/ml (0, 18, 36 and 91 mumol/l, respectively). During a 60-min exposure period, decreased chemiluminescence responses occurred to Staph. aureus at 5 micrograms/ml (P less than 0.01) and higher thiopental concentrations and to E. coli at 10 micrograms/ml (P less than 0.01) and higher concentrations, as a sign of depressed oxidative microbicidal activity.

Immunodeficiency in latent feline leukemia virus infections

Challenge of naive experimental animals with a retroviral inoculum may result in one of two broad sequelae. The first is the establishment of an appropriate humoral and cellular immune response leading to a condition of immunity to subsequent infection with the retrovirus. Alternatively, the host may fail to develop a successful immune response, resulting in a chronic viremia associated with immunosuppression and ultimately death due to secondary pathogens. An alternate disease course is the establishment of a latent infection characterized by the presence of neutralizing antibody and strong cellular immune reactivity. Recent data from the feline leukemia virus (FeLV) system suggest that cats infected with this virus may develop immunosuppression in the form of persistent neutrophil dysfunction. The potential effect of this cellular dysfunction is the possible susceptibility of the host to the same opportunistic pathogens which are responsible for the increased mortality noted in chronic FeLV infections. These data demonstrate that persistent retroviremia is not essential for the establishment of immunosuppression. This overview presents data accumulated from the feline model of the human acquired immunodeficiency syndrome (AIDS) and discusses its relationship to human retroviral infections.

Polymorphonuclear leukocyte function in HIV-1-infected chimpanzees

The chemiluminescent characteristics of enriched populations of neutrophils from control and HIV-infected chimpanzees were assessed. Neutrophils from HIV-infected chimpanzees were suppressed in their ability to generate a normal response to particulate and soluble stimuli when compared to normal and hepatitis non-A, non B-infected controls. Particulate (latex beads) stimulation of neutrophils resulted in an aberrant response when contrasted with controls. Normal control responses were characteristically biphasic while the response from hepatitis NANB HIV-infected chimpanzees was not biphasic. Neutrophils challenged with a soluble (phorbol ester) stimulant also demonstrated a suppressed response. These data suggest that HIV infection has an additive suppressive effect on neutrophil function in chimpanzees previously infected with hepatitis NANB. The suppression of chimpanzee neutrophil function following HIV infection is similar to that seen in other non-primate viral and retroviral infections.

Effect of NCO-700, an inhibitor of thiol protease, on reactive oxygen production by chemotactic peptide-stimulated rabbit peripheral granulocytes

The specific thiol protease inhibitor, NCO-700, which is related to L-trans-epoxysuccinylpeptides, inhibited oxidant production by chemoattractant-stimulated rabbit polymorphonuclear leukocytes. NCO-700 could also scavenge active oxygen generated from sodium hypochlorite-hydrogen peroxide and hypoxanthine-xanthine oxidase systems.

Exudate polymorphonuclear leukocytes isolated from skin chambers are primed for enhanced response to subsequent stimulation with chemoattractant f-Met-Leu-Phe and C3-opsonized yeast particles

The ability to respond metabolically to stimulation with both soluble and particulate substances was investigated in human polymorphonuclear leukocytes (PMNLs) isolated from an aseptic inflammatory reaction. Exudate PMNLs isolated from skin chambers (E-PMNLs) and blood PMNLs isolated from the peripheral blood (B-PMNLs) of the same individual were investigated in parallel. E-PMNLs were primed, resulting in an increased chemiluminescence (CL) response to subsequent stimulation with the chemotactic peptide formyl-methionyl-leucyl-phenylalanine (FMLP) (334%) and serum-opsonized yeast particles (C3 yeast) (201%), as compared to B-PMNLs. Phorbol myristate acetate (PMA) on the other hand, induced a CL response in E-PMNLs that was only 70% of the response obtained in B-PMNLs. A similar primed state resulting in enhancement of the CL response to FMLP and C3 yeast could be induced in B-PMNLs by pretreatment with a bacterial culture filtrate. Pretreatment of E-PMNLs with the bacterial culture filtrate, however, did not increase the CL response to FMLPs any further. The enhanced functional response to FMLPs in E-PMNLs was accompanied by an increased binding of the peptide, demonstrated by a doubling of the amount of bound f-Met-Leu-[3H]Phe (209%), as compared to B-PMNLs. The increased C3-yeast-induced CL generation in E-PMNLs was accompanied by an increased ingestion and attachment of C3-opsonized yeast particles. The enhancement of phagocytosis in E-PMNLs was, however, dependent upon the opsonin used, since IgG-opsonized yeast particles were phagocytosed to the same extent by E-PMNLs and B-PMNLs, thereby indicating that selective receptor modulation is also involved in the priming of E-PMNLs for an enhanced response to C3-yeast. These results show that exudate cells isolated from skin chambers are modulated with respect to receptor-mediated functions resulting in an increased metabolic response to FMLP coupled with an increased binding of the peptide and an increased phagocytosis of C3-coated yeast particles. Receptor modulation during exudation may be an important mechanism in regulating the inflammatory response by PMNLs.

Modulation of oxygen-free radicals from human leukocytes during halothane- and enflurane- induced general anesthesia

Oxidative metabolism correlates with the release of microbiocidal oxygen-free radicals, measured as luminol-dependent chemiluminescence. The effect of general anesthesia on the oxidative metabolism of human leukocytes was investigated. Sixteen patients undergoing a halothane-induced general anesthesia and 14 patients receiving an enflurane-induced general anesthesia participated in the study. Halothane-induced anesthesia was accompanied both by a suppression of basic chemiluminescence and by a decrease in chemiluminescence during the phagocytosis of zymosan A. This was monitored 15 min, 30 min and 60 min after starting general anesthesia and compared to the level of chemiluminescence before starting general anesthesia. Ninety minutes after finishing general anesthesia, a significant recovery of chemiluminescence was seen to exceed the level before general anesthesia. Comparable findings were observed with enflurane-induced general anesthesia, suggesting a decreased release of oxygen-free radicals during general anesthesia, and afterwards an increase exceeding the initial level.

Impaired neutrophil function during anesthesia and surgery is due to serum factors

Neutrophil function was assessed in patients undergoing anesthesia and surgery using a chemiluminescence (CL) assay. With the anesthetic agents enflurane and nitrous oxide, peroperative CL (99.1 mV; 13.8 SEM: postinduction but prior to surgery) was significantly lower than the preoperative value (146.5 mV; 14.1 SEM) with a mean fall of 30% (P less than 0.001). CL measurements taken 24 hr postoperatively were significantly increased (193.9 mV; 16.4 SEM) over the pre- and peroperative values, showing mean increases of 32 and 96%, respectively (P less than 0.001 in both cases). The inhibitory influence on CL appeared to be due to serum factors since peroperative patients' sera inhibited control neutrophils. Significantly depressed levels of the complement component C3 and IgG detected during the peroperative period (P less than 0.05) may explain this phenomenon. Postoperatively, C3 and IgG levels returned to normal. The transient decrease in peroperative neutrophil function may be a contributory factor to the establishment of postoperative sepsis in surgical patients.

Influence of antibiotics on formylmethionyl-leucyl-phenylalanine-induced leukocyte chemiluminescence

The effect of three antimicrobial agents, penicillin G, ampicillin, and chloramphenicol, on luminol-enhanced chemiluminescence of polymorphonuclear leukocytes stimulated by the chemoattractant formylmethionyl-leucyl-phenylalanine was studied. An inhibitory effect of penicillin G and of ampicillin was demonstrated, whereas chloramphenicol gave rise to an enhancement of the chemiluminescence response from polymorphonuclear leukocytes. These effects could be due to interaction between the drugs and the polymorphonuclear leukocytes, but they could also be the result of interference with the generation of light without any effect on the cells. Therefore, the effects of the same antimicrobial agents on the chemiluminescence generated from a cell-free system consisting of myeloperoxidase and hydrogen peroxide were investigated in parallel. The results obtained in the cell-free system were almost identical to those obtained in the cell system; i.e., penicillin G and ampicillin caused an inhibition and chloramphenicol caused an enhancement of the light emission. These results indicate that observed effects induced by drugs in a chemiluminescence assay are not necessarily due to interaction between the drug and polymorphonuclear leukocytes but may be caused by interference with other components of the assay. In view of these findings, the conflicting data reported in the literature on the effects of antimicrobial agents on phagocyte function are discussed.

Comparison of Candida killing activity measured by chemiluminescence and cytomorphological methods in human phagocytes

Phagocyte function can be assayed by many laboratory tests including a cytomorphological method that uses Candida cells as target. The aim of this study was to correlate this technique with the production of toxic oxygen metabolites, measured by chemiluminescence (CL). The biological function of polymorphonuclear (PMN) cells and monocytes from the blood of 24 normal subjects and 25 patients with immunodeficiency diseases were studied. CL was measured using opsonized zymosan as the stimulating agent and, for the evaluation of Candida killing activity, C. pseudotropicalis and C. albicans were used as targets. A linear correlation between CL and lytic activity was observed with both PMN and monocytes from normal subjects and patients (r = 0.563 to 0.955; P less than 0.05 to less than 0.001). Our results indicate that the production of toxic oxygen metabolites, as measured by CL is closely related to the killing of Candida by PMN and monocytes.

The effects of glucocorticosteroids on the chemiluminescence response of bovine phagocytic cells

The effects of corticosteroids on the chemiluminescence response of bovine phagocytic cells were determined both in vitro and in vivo. The in vitro addition of hydrocortisone or dexamethasone had no significant effect on the chemiluminescence response of leukocytes in a whole blood or purified polymorphonuclear leukocyte (PMN) population. Cattle that received a single 20 mg dose of dexamethasone or three 20 mg doses of dexamethasone (given 24 hours apart) demonstrated the expected effects on the bovine leukogram (leukocytosis, neutrophilia, lymphopenia, eosinopenia, and monocytosis) and also demonstrated the expected suppressive effect on lymphocyte response to phytohemagglutinin (PHA). However, neither a single nor multiple dexamethasone treatment(s) had an effect on the chemiluminescence response of phagocytes in whole blood, but significantly enhanced the chemiluminescence response of the purified PMN leukocyte population. There was no significant difference between the two dexamethasone treatment groups in either the degree or duration of the effects observed in the chemiluminescence or lymphocyte response assays.

Effects of eugenol on polymorphonuclear cell migration and chemiluminescence

In this study, the effects of eugenol on human polymorphonuclear (PMN) cell migration and chemiluminescence were examined in vitro. Utilizing zymosan-activated serum or crude Bacteroides sonicate fractions as chemotractants, we found that eugenol inhibits PMN migration at 6.6 X 10(-2) to 6.6 X 10(-5) mol/L (P less than 0.05). Also, similar effects were observed in PMNs pre-incubated in eugenol. Regardless of concentration, eugenol was not found to induce chemotaxis of PMNs. An examination of PMN membrane activation through chemiluminescence gave results consistent with the chemotaxis data, demonstrating a decrease in light emission at concentrations as low as 6.6 X 10(-6) mol/L (P less than 0.05). In view of these data, the potential effect of eugenol on in vivo (sulcular or periapical) PMN function deserves further study.

Granulocyte microbicidal function in patients undergoing major abdominal surgery under balanced anaesthesia

Granulocyte microbicidal functions were studied in 11 major abdominal surgery patients with the luminol-enhanced chemiluminescence method. The responses of granulocytes in phagocytosis of zymosan, S. aureus and E. coli and responses to N-formylmethionyl-leucylphenylalanine (FMLP) were unaffected by surgery. The percentage of high-peroxidase-activity cells among neutrophils was increased on postoperative days 1 (P less than 0.01) and 3-4 (P less than 0.05). We propose that microbicidal-related oxidative phagocytic functions of granulocytes are well maintained after major abdominal surgery under balanced anaesthesia.

Plasma endotoxin levels and functions of peripheral granulocytes in surgical patients with respiratory distress syndrome

Plasma endotoxin levels and granulocyte functions (chemiluminescence and chemotaxis) were determined in fifty-two patients with postoperative sepsis. Seventeen had concurrent respiratory distress syndrome (RDS group) and the remaining thirty-five were free of the syndrome (non-RDS group). The plasma endotoxin concentrations were higher in the RDS group than in the non-RDS group (p less than 0.001). All nine patients with particularly high levels (greater than 80 pg) belonged to the RDS group. We noted a positive correlation in chemiluminescence (p less than 0.001, r = 0.67) and a negative correlation in chemotactic activity (p less than 0.001, r = 0.69). To determine whether endotoxin alters normal granulocyte functions in vitro, healthy granulocytes were treated by the endotoxin (E. coli 0111:B4). There was an increase in chemiluminescence and a decrease in chemotactic activity, as observed in vivo. Furthermore, normal granulocytes chemiluminescence was increased by pretreatment of RDS plasma showing high endotoxin levels in vitro (n = 4, p less than 0.05). Thus, endotoxin in the plasma probably plays an important role in marked changes in peripheral granulocyte functions in patients with respiratory distress syndrome.