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PubMed1976

Resistance of Neisseria gonorrhoeae to ingestion and digestion by phagocytes of human buffy coat.

In tests in vitro with the phagocytes of human buffy coat, a recent isolate of Neisseria gonorrhoeae, which was pilated, formed small colonies and resembled the virulent Kellogg type 2 (strain BS), resisted ingestion more than did another isolate (strain AL), which was non-pilated, formed large colonies and resembled the avirulent Kellogg type 4. Some members of both strains survived for significant periods within the phagocytes in test conditions that tended to minimise rather than maximise such survival; and strain BS had a greater capacity for intracellular survival than strain AL, with some of its members surviving for at least 8 h. Resistance to phagocytic ingestion is one important invasive mechanism of gonococci, and resistance to phagocytic digestion may also play a role in pathogenicity.

Cell Count↗
PubMed1977

Inhibitory effects of plasma from uraemic patients on human mononuclear phagocytes cultured in vitro.

Human mononuclear phagocytes were cultured in plasma from uraemic patients. The presence of uraemic plasma during the engulfment or digestion of 125I-labelled Candida albicans did not inhibit these functions in mononuclear phagocytes cultured for 8 days under normal condition. When normal human macrophages were cultured in the presence of uraemic plasma for 2-4 days, a marked detachment of the cells from the glass coverslips was registered. The phagocytic function of the remaining cells was impaired. Creatinine, urea and methylguanidine in concentrations higher than those usually measured in plasma from uraemic patients did not influence the functional properties of the cells. The inhibitory effect of uraemic plasma on the mononuclear phagocytes is suggested as an explanation for the increased frequency of infections in uraemic patients.

Candida albicans↗
PubMed1978

Cigarette smoke and phagocyte function: effect of chronic exposure in vivo and acute exposure in vitro.

Phagocytic function was studied in mice chronically exposed to cigarette smoke, and the effects of in vitro exposure to cigarette smoke on macrophage activity were also assessed. Cultures of radiolabeled Pseudomonas aeruginosa were employed to investigate phagocyte activity in vivo and in vitro. Mice were exposed on weekdays to fresh cigarette smoke for periods up to 37 weeks and the bactericidal and clearance activity of their lungs was measured. Both pulmonary clearance and bactericidal activity was impaired. The clearance of intravenously injected bacteria from the blood of smoke-exposed mice occurred at the same rate as in control mice, but the accumulation of radiolabel by the liver was decreased. In addition, the rate of elimination of radiolabel from the liver was less than the controls. Macrophages exposed to cigarette smoke in vitro initially had a depressed phagocytic rate, but if phagocytosis over a prolonged period was measured it was eventually enhanced over the rate of control macrophages. The vapor phase of cigarette smoke could also transiently inhibit and then enhance the phagocytic activity.

Animals↗
PubMed1979

Generation of hydroxyl radical by enzymes, chemicals, and human phagocytes in vitro. Detection with the anti-inflammatory agent, dimethyl sulfoxide.

Methane (CH(4)) production from the anti-inflammatory agent, dimethyl sulfoxide (DMSO), was used to measure .OH from chemical reactions or human phagocytes. Reactions producing .OH (xanthine/xanthine oxidase or Fe(++)/EDTA/H(2)O(2)) generated CH(4) from DMSO, whereas reactions yielding primarily O-(2) or H(2)O(2) failed to produce CH(4). Neutrophils (PMN), monocytes, and alveolar macrophages also produced CH(4) from DMSO. Mass spectroscopy using d(6)-DMSO showed formation of d(3)-CH(4) indicating that CH(4) was derived from DMSO. Methane generation by normal but not chronic granulomatous disease or heat-killed phagocytes increased after stimulation with opsonized zymosan particles or the chemical, phorbol myristate acetate. Methane production from DMSO increased as the number of stimulated PMN was increased and the kinetics of CH(4) production approximated other metabolic activities of stimulated PMN. Methane production from stimulated phagocytes and DMSO was markedly decreased by purportedly potent .OH scavengers (thiourea or tryptophane) and diminished to lesser degrees by weaker .OH scavengers (mannitol, ethanol, or sodium benzoate). Superoxide dismutase or catalase also decreased CH(4) production but urea, albumin, inactivated superoxide dismutase, or boiled catalase had no appreciable effect. The results suggest that the production of CH(4) from DMSO may reflect release of .OH from both chemical systems and phagocytic cells. Interaction of the nontoxic, highly permeable DMSO with .OH may explain the anti-inflammatory actions of DMSO and provide a useful measurement of .OH in vitro and in vivo.

Cells, Cultured↗
PubMedDate not supplied

Characterization of mononuclear phagocytes in human CSF using membrane markers.

The purpose of this investigation was to demonstrate those membrane receptor sites on mononuclear phagocytes of human CSF which provide additional evidence for their monocytic origin and function. Using a heterologous system, sheep red blood cells were coated with IgG- and IgM-fraction of the anti-Forssman-antiserum of rabbits. In another series of experiments, sheep red blood cells were additionally sensitized with fresh human serum as a source of complement. The possible inhibitory effect of human IgG on the uptake of red cell antibody complexes was tested. Washed and pretreated sheep red cells were added to different fresh CSF specimens from patients, whose CSF exhibited no conspicious biochemical, serologic or cytologic alterations. The percentage of phagocytizing mononuclear phagocytes was evaluated. When the particular IgG EA reagent described was utilized, most of the mononuclear phagocytes consistently exhibited the IgG- and complement-receptor activity which selectively characterizes blood monocytes and related cells.

Binding Sites, Antibody↗
PubMed1977

Comparison of phagocytic and chemiluminescence response of human polymorphonuclear neutrophils.

The phagocytic activity and the chemiluminescence response of human polymorphonuclear neutrophils were studied with normal human serum used as opsonin for S. typhimurium and S. aureus. When serum was heated, chelated with ethyleneglycol tetraacetic acid (EGTA), or absorbed with zymosan, there were reduction of phagocytic activity for S. aureus and a comparable reduction of chemiluminescence; a 50 per cent decrease in phagocytosis by neutrophils corresponded to a 50 per cent reduction in the chemiluminescence response. In contrast, S. typhimurium was successfully phagocytized in serum treated with MgEGTA (complement--alternate pathway intact; classic pathway blocked), and chemiluminescence was reduced by only 20 per cent under the same conditions. Both neutrophil phagocytic and chemiluminescence responses for S. typhimurium were abolished when serum was heated at 56 degrees C. or adsorbed with zymosan. These findings suggest that both phagocytosis and chemiluminescence in neutrophils are interrelated, and the chemiluminescence response of neutrophils may be a reliable assay for measuring serum opsonic activity.

Egtazic Acid↗
PubMed1979

Phagocytic activity of rabbit pulmonary macrophages at different temperatures.

Phagocytic activity of pulmonary macrophages (PM) in contact with latex particles was studied in a group of twelve adult male rabbits, by means of in vitro phagocytosis tests at 35, 37, 39 and 41 degrees C. The phagocytic index at 35 degrees C was 14.70 (sigma = 4.5); at 37 degrees C, 19.61 (sigma = 4.7); at 39 degrees C, 22.45 (sigma = 5.1), and at 41 degrees C, 25.02 (sigma = 5.4). The value of the correlation coefficient between phagocytic index and temperature was r = 0.6022. The previous results allowed to conclude that there is lineal and direct relationship increase between phagocytic indexes and temperature.

Animals↗
PubMed1978

Use of lysostaphin to remove cell-adherent staphylococci during in vitro assays of phagocyte function.

Lysostaphin, a bacteriolytic enzyme, has been used to remove cell-adherent and extracellular Staphylococcus aureus from phagocyte-bacterial mixtures in vitro. Lysostaphin kills S. aureus more rapidly than penicillin, is not toxic for phagocytic cells and, when used for short periods at low concentrations, appears to enter neither human nor mouse mononuclear phagocytes. The use of lysostaphin provides the basis of a simple reliable direct in vitro assay for measuring the attachment and ingestion of S. aureus by phagocytic cells.

Bacteriolysis↗
PubMed1979

Role of phagocytic cells in host defence in relation to trauma--a brief review.

Present evidence available support a relationship between phagocytic cell function and survival from various types of trauma, e.g. burn, traumatic shock, and haemorrhage. Both polymorphonuclear phagocytes and mononuclear phagocytes (monocytes and macrophages) participating in the body's host defence are of crucial importance in preventing post-traumatic infections by microorganisms. The role of macrophages constituting the reticuloendothelial system (RES) in relation to trauma is paid special attention in this review. Deficit in a humoral opsonic glycoprotein (alpha 2 SB glycoprotein) important for reticuloendothelial phagocytosis is described in various types of traumatic injuries, and the role of RES in relation to pulmonary insufficiency is finally summarized.

Animals↗
PubMed1978

Plasma cathepsin activity and reticuloendothelial phagocytic function during hemorrhagic shock.

The present study evaluated two forms of hemorrhagic shock in terms of changes in plasma lysosomal enzyme activity, reticuloendothelial system (RES) phagocytic function, and plasma opsonic activity. Hemorrhagic shock was induced in rats by withdrawal of a fixed volume of blood equivalent to 3% body weight or by maintaining the arterial blood pressure at 40--45 mm Hg. Plasma cathepsin activity did not increase until after one hour of hypotension, and was increased 2.7-fold two hours after a 3% body weight hemorrhage and 11-fold after two hours at a blood pressure of 40--45 mm Hg. Phagocytic index and plasma opsonic activity were decreased in animals reinfused at 0, 30, or 120 minutes following a 3% body weight hemorrhage and in animals reinfused 0, 30, and 90 minutes following hemorrhage to a blood pressure of 40 mm Hg. There was a strong temporal relationship between the changes in phagocytic index and plasma opsonic activity; however, the decrease in RES function occurred earlier than the increase in plasma lysosomal enzyme activity. These results suggest that the depression of RES function during shock may be mediated, in part, by a deficit in circulating opsonic activity and that RES depression occurs prior to shock-induced cellular injury during hemorrhagic shock.

Animals↗
PubMed1979

Fixed phagocytes in the freshwater snail Lymnaea stagnalis.

Morphological and histochemical examination of the blood and connective tissue of the freshwater snail Lymnaea stagnalis injected with various types of foreign particulate materials has shown the existence of free as well as fixed phagocytic cells. The morphology of the fixed phagocytes is described, and the phagocytic system of the snail is compared with that of other molluscan species.

Animals↗
PubMed1976

An approach to the characterization of mononuclear phagocytes involved in pathological processes.

Cells participating in an inflammatory response are derived from the bone marrow (i.e. granulocytes and monocytes) or lymphoid organes (i.e. T and B lymphocytes), or of mesenchymal origin (i.e. fibroblast, reticulum cells). The identification of these different kinds of cell in the inflammatory exudate is often difficult, because the morphological characteristics are not specific enough. For example, in the morphological description of pathological processes often terms such as round-cell infiltration and mononuclear cells are used, which is confusing. For the clear understanding of the course of an inflammatory reaction and the effect of anti-inflammatory drugs it is necessary, however, to define exactly the participating cells. Such an identification can be performed on the basis of morphological, cytochemical and immunological characteristics of the cells, together with their kinetic parameters. These characteristics have been established for murine mononuclear phagocytes. Recently these characteristics have also been studied in human promonocytes, monocytes and skin macrophages. The results show that human mononuclear phagocytes are in many respects similar to those of mice. On this basis an outline for the participation of mononuclear phagocytes in pathological processes (i.e. inflammatory processes, neoplastic processes, and storage disorders) has been made.

Animals↗
PubMed1976

A test of granulocyte membrane integrity and phagocytic function.

An assay of granulocyte viability has been developed which yields information about rwo important cell parameters, cell membrane integrity and phagocytic activity. The assay is based on the fact that only live cells can accumulate fluorescein, which is enzymatically split from the nonfluorescent substrate fluorescein diacetate. Dead cells, on the other hand, become permeable to the fluorescent red dye ethidium bromide. When cells are exposed first to opsonized zymosan particles, which they can phagocytize, then to a combination of these fluorescent dyes, one can distinguish microscopically between dead cells with fluorescent red nuclei, live cells which fluoresce green, and live cells with phagocytic function which are swollen with the pink zymosan particles in a green fluorescing cytoplasm. This assay takes 20--30 min and can be used to distinguish different degrees of cellular damage after cryopreservation.

Blood Preservation↗
PubMed1977

Effect of endotoxin-induced shock on the reticuloendothelial system. Phagocytic activity and DNA-synthesis of reticuloendothelial cells following endotoxin treatment.

There was a marked decrease in the RES phagocytic activity during the first 12 hours after injection of high concentrations of endotoxin in rats. Phagocytic activity then increased considerably, reaching maximum values on days 3 to 5 and it was still higher than in control animals 20 days later. Parallel studies on 3H thymidine incorporation showed a significant increase in the rate of DNA-synthesis of reticulum cells of the liver during the 5 days period following endotoxin injection. Peak values were obtained on day 2 when the number of labelled cell were 50 times higher than in the controls. A likely reason for the increased DNA-synthesis is a repair of RES following endotoxin induced damage but it may also represent an endotoxin induced proliferation of reticulum cells that may at least partly account for the enhanced phagocytic activity.

Animals↗
PubMed1977

Functional development of phagocytic activity of the spleen.

The improvement of phagocytic activity of organs was studied in rats by means of 99mTc sulfur colloid uptake. This function was measured in the newborn rat, 1-, 2-, 3-, and 4-week-old baby rats and in adult rats. Organ distribution of the 99mTc-S-colloid showed marked phagocytic activity of the liver in all age groups including the newborn period. Phagocytosis in bone marrow was markedly increased and that in spleen markedly decreased at the time of birth. However, rapid improvement of phagocytic activity with age was prominent in the spleen.

Animals↗
PubMed1977

Differences in pyrogen production by mononuclear phagocytes and by fibroblasts or HeLa cells.

Phagocytosis of bacteria stimulates "professional" phagocytes to produce and release endogenous pyrogen (EP), the protein that mediates fever. To determine whether "nonprofessional" phagocytes also have this capacity, mouse and human fibroblasts and HeLa cells were cultured after ingestion of latex or chicken erythrocytes (CE), and EP release into culture supernate measured by mouse assay. No detectable pyrogen was released by these cell types after phagocytosis, whereas both latex and CE stimulated EP production by cultured mouse macrophages. These studies support the hypothesis that only professional phagocytes of bone marrow origin synthesize EP and induce fever.

Animals↗
PubMed1976

An assessment of intratumor phagocytic and surface marker-bearing cells in a series of autochthonous and early passaged chemically induced murine sarcomas.

Single cell suspensions from five different 3-methylcholanthrene-induced tumors in CBA mice were examined in the autochthonous host and sequentially for 5-11 passages. They were also examined for Fc receptor-bearing, phagocytic, theta antigen-positive, and surface immunoglobulin-bearing cells. The preparations contained a high proportion of phagocytic and marker-bearing cells both in the original host and during early passage. This proportion was consistent for any particular tumor and passage. Between different tumors, however, the proportions were sufficiently different to allow the tumor to be identified on this basis; this suggested that various chemically induced tumors may be unique in their tumor-host relationship as measured by the type of cells which infiltrate them. With on-going early passage of the tumors, the proportion of marker-bearing cells decreased to a constant level in most instances, mainly because of a reduction in the percentage of phagocytic cells. The tumor with the least macrophages (MBQA, less than 5%) consistently appeared more rapidly and killed the host more rapidly than did the tumor with the most macrophages (MBQD, 15-30%), but was not significantly different in its growth rate. The theta antigen- and Fc receptor-positive cells within these tumors were derived from the animal receiving the tumor inoculum, and thus represented host cell infiltration of the tumor. The results were discussed with reference to fundamental concepts of the immunology of chemically induced tumors and the importance of host cell infiltration within these tumors.

Animals↗
PubMed1977

Inhibitory action of galactose on phagocytes from normal and hypergalactosemic chicks.

The inhibitory effect of galactose on phagocyte function was investigated in normal and hypergalactosemic chicks by monitoring the in vitro killing of Escherichia coli by leukocytes and the in vivo clearance of colloidal 125I-labeled bovine serum albumin ([125I]BSA) from the circulation. Elevated levels of galactose (30 mM) significantly impaired the bactericidal activities of leukocytes from both control and hypergalactosemic chicks. However, the latter cells were more susceptible to the galactose-dependent inhibition. Leukocytes from hypergalactosemic chicks displayed near-normal bactericidal activity when assayed in vitro under simulated normal conditions in the absence of galactose. Mean corrected phagocytic indexes, obtained from data on the clearance of colloidal [125I]BSA, were calculated to be 0.358 and 0.299 for control and hypergalactosemic chicks, respectively. Moreover, increased concentrations of galactose significantly impaired the bactericidal activity of circulating leukocytes but did not significantly affect the phagocytic activity of the reticuoendothelial system.

Animals↗