Zinc supplementation aggravates body fat accumulation in genetically obese mice and dietary-obese mice

Human colostrum, the first product of lactation, has antioxidant properties and inhibits selected enzyme and bactericidal activities of human neutrophils. We examined the subsequent product of lactation, mature human milk, with respect to its antioxidant activities, its effects on neutrophil enzyme activities (myeloperoxidase, beta-glucuronidase, and lysozyme), and its effects on neutrophil bactericidal and phagocytic activities. Mature human milk displayed antioxidant characteristics similar to those of human colostrum, reducing cytochrome c and consuming H2O2. Mature milk also displayed colostrum-like characteristics in depressing neutrophil myeloperoxidase and beta-glucuronidase activities, but not in altering lysozyme activity. Neutrophil bactericidal activity against Staphylococcus aureus was depressed by both mature milk and colostrum, without dramatic effects on phagocytic activity. These data show that mature milk shares characteristics with human colostrum that may result in anti-inflammatory effects, but the magnitude of these effects is generally smaller.     

Influence of To?pa Peat Preparation on the phagocytic activity and bactericidal properties of granulocytes in healthy volunteers

It was found, that To?pa Peat Preparation (TPP) administered to healthy volunteers in doses of 100-300 mg/day during 14 days evoked the stimulation of the phagocytic and bactericidal activity of the granulocytes. The dose of 600 mg/day causes only a transient and insignificant increase of phagocytic and bactericidal properties of the granulocytes.     

Effect of industrial contact with penicillin on the immunological reactivity of workers

Immunological examination of women occupied in production of penicillin revealed a decrease in the phagocytic activity of the blood neutrophiles and the bactericidal properties of the skin, an increase in the quantitative composition of the autoflora of the skin and changes in its biochemical properties. Correlation between the changes in the values of the natural non-specific immunity as dependent on the level of the contact with the antibiotic was shown.     

Mechanisms for high methoxymorpholino doxorubicin cytotoxicity in doxorubicin-resistant tumor cell lines

While a large body of literature depicting relationships between depression or stress and immunity exists, few such studies have dealt with children, and none investigated myeloid cell-derived immunity. We investigated both phagocytosis and bactericidal activity against Staphylococcus aureus in children with major depressive disorder (MDD). We found that both MDD and stress influence the bactericidal but not the phagocytic activity of polymorphonuclear leukocytes. The data support the existence of psychobiologic effects in children and suggest possible mechanisms by which depression and stress may affect health.     

Postoperative ileus as an indication for a 2d operation during the early postoperative period

The phagocytic and bactericidal activities to Salmonella pullorum (strain 9-25) or Salmonella senftenberg (strain 99D) were examined in chicken splenic phagocytes from 0-day-old to 2-month-old chickens. The phagocytic activity against S pullorum increased in splenic phagocytes from chickens older than 7 days, but significant changes in activity against S senftenberg were not observed during the experimental period. The bactericidal activity of splenic phagocytes against S senftenberg was higher than that of phagocytes against S pullorum during the same period. Increase of the bactericidal activity against S pullorum was observed with increasing age, but the activity of the splenic phagocytes from 0-day-old chickens against S senftenberg was similar to that of the phagocytes from 2-month-old chickens. Although delayed hypersensitivity was confirmed by delayed wattle reaction in 2-month-old chickens sensitized with living S pullorum, the sensitization did not markedly affect phagocytic and bactericidal activities.     

Chronokinetics of active biliary ampicillin secretion in rats

To estimate the functional maturity of the phagocytic defence in neonatal calves, we analyzed the characteristics of blood phagocytes from calves (n = 10) 1 h post partum (p.p.) and 4 h p.p. At 1 h p.p., all calves were colostrum-deprived, while 5 calves had received colostrum before the 4 h p.p. sampling. The results were compared to those obtained from 3-9-week-old calves (n = 10). Phagocytic and oxidative burst activity of polymorphonuclear leukocytes (PMNL) and monocytes were determined in whole blood and separately analyzed by flow cytometry. In neonates prior to colostrum ingestion (1 h p.p.), phagocytic activity of PMNL against non-preopsonized E. coli was lower when compared to PMNL of 3-9-week-old calves. Opsonization of bacteria with pooled plasma from adult animals only partially restituted this lower PMNL phagocytic activity, indicating that humoral as well as cellular aspects of PMNL phagocytosis are altered in neonatal calves. In contrast to PMNL, monocytes of neonates exhibited an enhanced phagocytic activity. The oxidative burst activity of PMNL, as well as of monocytes was higher in newborn calves. During the first 4 h of life, the activities of blood phagocytes changed. Colostrum ingestion was accompanied by an increase in the percentage of phagocytizing PMNL and monocytes. This increase was absent in colostrum-deprived calves. In contrast, the oxidative burst activity of phagocytes decreased with age. In monocytes, the decrease of oxidative burst activity was only observed in colostrum-fed calves. In conclusion, some blood phagocyte functions in calves were found to be immature at birth, but these functions are presumably compensated by high absolute PMNL numbers and by other the more active mechanisms.     

Prolonged but reversible neutrophil dysfunctions differentially sensitive to granulocyte colony-stimulating factor in children with acute lymphoblastic leukaemia

Treatment of average-risk acute lymphoblastic leukaemia (ALL) in children consists of 6 months of intensive chemotherapy followed by 18 months of maintenance therapy. Polymorphonuclear leucocyte (PMN) functions from children with ALL were studied in order to evaluate and compare the toxicity of the initial intensive treatment with the toxicity of the subsequent less intensive maintenance treatment. H2O2 and O2- production, evaluated by chemiluminescence, were significantly decreased during the intensive period but returned to normal values when maintenance therapy began. In contrast, bactericidal activity against Gram-positive and Gram-negative microorganisms remained at low levels throughout the treatment but returned to normal values in patients off chemotherapy. PMN from patients on maintenance therapy exhibited an excess of morphological changes associated with apoptosis. This was confirmed by standard two-colour flow cytometry which revealed an increase in the number of hypodiploid cells, and increased expression of membrane phosphatidylserine together with a drastic reduction in the expression of the Fcgamma receptor IIIB (CD16). These defective PMN were differentially sensitive to the effects of granulocyte colony stimulating factor (G-CSF): G-CSF induced similar increase in chemiluminescence in control and patient PMN; GSF partially corrected the defective bactericidal activity; G-CSF did not affect the accelerated PMN apoptosis. These observations indicate that ALL children undergoing chemotherapy present PMN defective functions which are partially sensitive or even resistant to G-CSF.     

Stimulation by retinoic acid of prostaglandin production and its inhibition by tumor promoters in mouse myeloid leukemia cells

Retinoic acid induced lysozyme activity in mouse myeloid leukemia M1 cells. It also stimulated the synthesis and release of prostaglandins such as prostaglandin F2alpha, E2, and D2 by the cells. The particulate fraction of retinoic acid-treated M1 cells converted arachidonate to prostaglandins, and this conversion was almost completely inhibited by indomethacin. Retinol, retinal and retinyl acetate, but not the pyridyl analog of retinoic acid, also induced lysozyme activity and stimulated synthesis and release of prostaglandins. Indomethacin inhibited the induction of lysozyme activity by retinoic acid. The induction of lysozyme activity and the stimulation of prostaglandin E2 production were dependent on the concentration of retinoic acid. Kinetic studies showed that stimulation of prostaglandin E2 production by retinoic acid was followed by induction of lysozyme activity. The tumor promotor 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and phorbol 12,13-didecanoate inhibited the induction of lysozyme activity by retinoic acid, but 4 alpha-phorbol didecanoate and phorbol did not. TPA and phorbol 12, 13-didecanoate, but not 4 alpha -phorbol didecanoate, also inhibited the stimulation of prostaglandin E2 production by retinoic acid. These results suggest that stimulation by retinoic acid of prostaglandin E2 production in M1 cells is a prerequisite for the induction of lysozyme activity. On the other hand, both retinoic acid and TPA inhibited the induction by dexamethasone of phagocytic activity, which is a typical functional marker of differentiation of M1 cells, without causing significant growth inhibition. Suboptimal concentrations of retinoic acid and TPA had synergistic inhibitory effects on the induction of phagocytic activity of M1 cells by dexamethasone.     

Methods of measuring lipid peroxidation products in exhaled air condensate and their clinical significance

Cellular and humoral immunity parameters were studied in patients with keratoconus at different stages, aged 14 to 49 years. The results showed the immune homeostasis to be impaired in patients with local involvement of the cornea. At a total system's level the patients developed shifts in the relative content of T-lymphocytes and their subpopulations, dysimmunoglubulinemia with increased levels of immunoglobulins of the primary immune response in the blood serum, high levels of the C3 and C4 components with a reduction of the total hemolytic activity of the complement, increased levels of NBT-positive and phagocytic cells, and a decrease of the activity of serum lysozyme.     

Expression of foreign gene in mycobacterium regulated by human Mycobacterium tuberculosis heat shock protein 70 promoter

PURPOSE: Phagocytosis is a major mechanism of defense against bacterial infections. The ingestion of bacteria by phagocytes involves a variety of cell membrane recognition structures and, among them, immunoglobulin receptors. The aim of this study was to test the phagocytic activity of granulocytes and monocytes of intensive care unit (ICU) patients, and to evaluate the effects of intravenous polyvalent immunoglobulins (IVIG) used as adjunct treatment of nosocomial pneumonia on some phagocyte membrane receptors of these patients. MATERIALS AND METHODS: The phagocytic activity of granulocytes and monocytes of 41 mechanically ventilated patients with nosocomial bacterial pneumonia was studied during the acute phase of infection. These ICU patients were compared with 21 hospitalized, noninfected volunteer patients hospitalized in a medical ward. Peripheral blood granulocytes and monocytes were studied. Of the 41 ICU patients, after randomization, 21 received IVIG at a dose of 1 g/kg for 3 days. The 41 ICU patients were compared with the 21 non-ICU, noninfected hospitalized controls. The 21 ICU patients who received 3 days of IVIG were also compared with the 20 ICU patients not receiving IVIG. Cells were tested in standard immunoglobulin-free medium (fetal calf serum) and in the presence of patients' serum. Blood granulocytes and monocytes were purified and separately exposed to three types of particles: antibody-coated erythrocytes (to test immunoglobulin receptors), opsonized zymosan (to test C3 receptors), and glutaraldehyde-treated erythrocytes (to test lectinlike or other nonspecific binding sites). Phagocytosis and superoxide anion production (oxidative burst) were measured. RESULTS: Granulocytes of ICU patients compared with those of non-ICU, noninfected patients exhibited a substantial decrease of zymosan ingestion (P < .05), whereas phagocytosis of other particles was normal. Monocytes from the ICU patients, compared with those of the non-ICU, noninfected patients, displayed an unselective overall decrease of phagocytic ability for the three particle types (P < .05). The phagocytosis activity of the three membrane receptor species of blood monocytes and granulocytes of ICU patients was not significantly modified by the IVIG infusion. For both monocytes and granulocytes, no significant improvement was observed in the fraction of cells that ingested at least one foreign particle and the mean number of particles per cell having phagocytized at least one foreign particle. Granulocyte and monocyte functions were also tested by the production of reduced ferricytochrome and no significant improvement in the oxidative burst was observed after infusion of IVIG. CONCLUSION: Infected ICU patients display a deficiency of phagocytosis membrane receptors of blood granulocytes and monocytes. The addition of IVIG to standard therapy does not improve the phagocytic activity of ICU patients with nosocomial pneumonia.     

Functional activity of peripheral blood neutrophils of rats during combined effects of hypoxia, hypercapnia and cooling

Functional activity of neutrophilic leukocytes was studied in blood of rats immediately following single and repeated gradual increase in carbon dioxide and decrease in oxygen concentrations with the ambient temperature at 2 to 3 degrees C. Phagocytic activity was shown to alter as the number of phagocytic neutrophilic granulocytes, absorptivity or the phagocytic index, and the coefficient of phagocytosis completeness were elevated and levels of oxygen-dependent and oxygen-independent metabolism were reduced.     

Insect cell stimulation by LPS requires the activity of cell-released proteases

The hemocyte line BTI-EA-1174-A from the lepidopteran insect Estigmene acraea responds to bacterial lipopolysaccharide (LPS) by an enhanced phagocytic reaction and a dose-dependent increase of lysozyme release [Wittwer et al., Dev Comp Immunol 21:323 (1997)]. This paper provides evidence for a strong proteolytic activity in cell culture supernatants occurring after addition of LPS (1 mg/ml). The proteolysis is caused by cell-released proteases and seems to be necessary for cell activation. Its inhibition by alpha 2-macroglobulin results in a dose-dependent reduction in cellular response strength. Phagocytic reactions, as well as lysozyme release, are lowered to about half in the presence of 0.0001 mg/ml alpha 2-macroglobulin. A nearly complete abolishment of activation was achieved with final concentrations of 1.0 mg/ml alpha 2-macroglobulin. The data presented allow us to conclude that the LPS-triggered proteolytic activity is an important part of the activation process; it occurs outside of the cells and delivers immune response activating factors.     

Perforated synapses of the neocortex and their role in the reorganization of the interneuronal relations in the postischemic period (a morphometric study)

Effects of some drugs on different levels of phagocytic activity of polymorphonuclear leukocytes (PMNL) of human peripheral blood were studied in vitro. The drugs were found to regulate the phagocytic activity of PMNL. This effect depended on the initial level of PMNL phagocytic activity but not on the drug appurtenance to a certain pharmacological group.     

Mercury exposure of maroon workers in the small scale gold mining in Suriname

Recent studies have reported reduced immunity in trained athletes. Scant information exists on changes in the immune function among trained children. The purpose of this study was to assess the effect of aerobic exercise on the phagocytic process of neutrophils and the complement system in young athletes. Subjects included prepubertal elite female gymnasts (n = 7) and untrained girls (n = 6) aged 10-12 years. Venous blood was withdrawn before, immediately post and 24 h following a 20-min run at a heart rate of 170-180 beats.min-1. Neutrophil random migration, chemotactic activity, bactericidal function and PMA/FMLP-stimulated superoxide anion release as well as various complement components were assessed. Net chemotaxis was found reduced (P < 0.05) 24 h following exercise (58 +/- 11 vs. 36 +/- 11 cells/field in gymnasts and 47 +/- 7 vs. 42 +/- 8 cells/field in untrained girls pre- and 24 h post-exercise, respectively). The basal values, as well as post-exercise values of bactericidal activity were lower (P < 0.05) in gymnasts as compared with the control group (0.8 +/- 0.3, 0.8 +/- 0.2 and 0.8 +/- 0.1 log decrease of colonies in gymnasts at pre-, immediately post-, and 24 h post-exercise, respectively and 1.1 +/- 0.1, 1.1 +/- 0.1 and 1.0 +/- 0.2 log decrease of colonies in controls, respectively). No significant effect on the bactericidal activity was observed in either group following exercise. The addition of homologous sera did not correct the bactericidal activity. PMA-stimulated superoxide anion release decreased (P < 0.05) among gymnasts immediately following exercise (5.7 +/- 0.4 vs. 4.4 +/- 1.0 mmol O2/10(6) PMN.min) and remained low 24 h later. The same trend was observed in FMLP-stimulated neutrophils but the data were not significant. Significantly decreased levels (P < 0.05) of the early complement components (C1Q, C1R) were also found following exercise (1.34 +/- 0.64 vs. 1.27 +/- 0.28 and 1.09 +/- 0.07 vs. 1.02 +/- 0.06 pre- and post-exercise in gymnasts and untrained, respectively). Furthermore, consistently lower C2 and C3 were observed in gymnasts compared with controls. Neutrophil dysfunction as well as impairment of the complement system seem to occur following exercise.     

Synergic antistaphylococcal properties of lactoferrin and lysozyme

Staphylococcus epidermidis colonises a wide range of implanted prosthetic devices, but rarely contact lenses -- despite a similarity in material composition. A conceivable explanation for this anomaly is the action of the tear defences, including the constitutive proteins lactoferrin and lysozyme. Therefore this study investigated the effect of lactoferrin, lysozyme and serum on the growth of S. epidermidis isolates in artificial tear fluid. Whether supplemented with serum alone or serum with either apolactoferrin or lysozyme, this medium induced a similar, strain-variable effect. However, simultaneous addition of these proteins induced a greater bactericidal or bacteristatic effect. Of those strains killed by the concerted action of apolactoferrin and lysozyme, the absence of serum led to a further increase in the bactericidal effect, whereas strains displaying bacteriostasis were unaffected by serum. Iron saturation of lactoferrin reversed the antimicrobial synergy of apolactoferrin and lysozyme. These results show synergy between lactoferrin and lysozyme which is dependent on the iron limitation of lactoferrin. As a bactericidal mechanism, this synergy is augmented by serum, but bacteriostasis remains unaffected by serum supplemention. Thus, the combination of lysozyme and lactoferrin may partly explain the low level of contact lens colonisation by S. epidermidis in vivo.     

Mediators of change in physical activity following an intervention in primary care: PACE

Lysozyme is able to lyse Gram-positive bacteria acting as muramidase on the peptidoglycan polymer. Gram-negative bacteria in vitro are not lysed by lysozyme. It was assumed that the peptido-glycan is protected by the outer membrane and thus that Gram-negative bacteria are not affected by lysozyme without the aid of other factors such as EDTA or complement which enable lysozyme to penetrate the outer membrane. Accidentally, Pellegrini et al. [(1992) J. Appl. Bacteriol., 72:180-187] found that lysozyme per se is able to kill some Gram-negative bacteria. On the basis of morphological and immunocytochemical findings obtained from chemically fixed bacteria, it was concluded that lysozyme does not lyse Gram-negative bacteria but affects the cytoplasm of for example, Escherichia coli, leading to its disintegration, whilst the membranes do not break down. In an attempt to clarify the action of lysozyme on E. coli, we employed cryotechniques including ultrarapid freezing, cryomicroscopy and freeze substitution, and immunolabeling. Bacteria that were immediately frozen after exposure to lysozyme remained morphologically intact. Individual bacteria plated on agar after exposure to lysozyme were mostly intact when frozen within a few seconds. However, inner and outer membranes of 80% of the bacteria were disrupted, whereas the cytoplasm of only a few bacteria showed signs of disintegration when bacteria were frozen with a delay of only 5 min of plating onto pure agar or agar containing growth medium. After a period of time of 15 min between plating onto agar and freezing, about 97% of the bacteria showed changes of disintegration of various extent. Immunolabeling showed that lysozyme binds to the outer cell membrane and may penetrate the membrane, reaching the periplasmic space and possibly the inner cell membrane. The ultrastructural findings and the results of antibacterial assays suggest that lysozyme is bactericidal for E. coli but is not able to induce disintegration. Disintegration is accomplished by changes of the environment starting at the cell membranes. The mechanism by which lysozyme penetrates the membrane, the way it acts to be bactericidal, and the way disintegration is initiated remain to be clarified.     

Stenotrophomonas (Xanthomonas) maltophilia: in vitro susceptibility to selected antimicrobial drugs, single and combined, with and without defibrinated human blood

Sixteen selected isolates of Stenotrophomonas maltophilia varied in susceptibility to the combined phagocytic/serum bactericidal activity of fresh defibrinated human blood (65 vol%). Four representative isolates (X1, X11, X25, and X50), which differed in susceptibility to cefepime, ceftazidime, rifampin, and timentin, were subjected to checkerboard microtiter broth dilution tests involving combinations of cefepime plus timentin, ceftazidime plus ofloxacin, cotrimoxazole plus timentin, rifampin plus polymyxin B, and rifampin plus polymyxin B nonapeptide; all combinations yielded additive or synergistic effects against all four strains. Unexpectedly, the combination of cefepime plus timentin was bactericidally active against the two cefepime-resistant isolates. This finding was substantiated by blood/broth plus combined antimicrobial drug assays. Cefepime plus timentin effectively killed all four test strains. Ofloxacin combined with ceftazidime was bactericidally active against the test strains, including two isolates (X11, X50) with intermediate ofloxacin sensitivity. Cotrimoxazole plus timentin in blood, but not in broth, was bactericidal for the timentin-resistant isolate X25. As expected, various triple combinations of chemotherapeutic agents in blood and broth revealed polymyxin B plus rifampin, regardless of the third combination partner, to exert bactericidal activity against all test strains. Similarly, rifampin combined with ofloxacin and ceftazidime was bactericidally active in blood and broth. The observation that timentin combined with cefepime was effective against cefepime-resistant strains of S. maltophilia might prove of clinical relevance with regard to chemotherapy of nosocomial infections due to multiple-antibiotic resistant strains of this opportunistic pathogen.     

Inactivation of protein kinase C in rat liver during late hypoglycemic phase of sepsis

Changes in protein kinase C (PKC) (calcium- and phospholipid-dependent protein kinase) activity in rat liver during different metabolic phases of sepsis were studied. Sepsis was induced by cecal ligation and puncture (CLP). Experiments were divided into three groups: control, early sepsis, and late sepsis. Early and late sepsis refers to those animals sacrificed at 9 and 18 h, respectively, after CLP. Hepatic PKC was extracted and partially purified by ammonium sulfate fractionation and DEAE-cellulose chromatography. PKC activity was assayed based on the rate of incorporation of 32p from [gamma-32P]ATP into histone. The results show that during early sepsis, both membrane-associated and cytosolic PKC activities remained relatively unaltered. During late sepsis, membrane-associated PKC was unaffected while cytosolic PKC activity was decreased by 19.5-34.4%. Kinetic analysis of the data on cytosolic PKC during late phase of sepsis reveals that the Vmax values for ATP, histone, Ca2+, phosphatidylserine, and diacylglycerol were decreased by 23.4, 22.1, 19.5, 25, and 34.4%, respectively, with no changes in their Km values. These data indicate that cytosolic PKC activity was inactivated in rat liver during late hypoglycemic phase of sepsis. Since PKC-mediated phosphorylation plays an important role in regulating hepatic glucose metabolism, an inactivation of cytosolic PKC may contribute to the development of hypoglycemia during late phase of sepsis.     

Biological activity of lysozyme after entrapment in poly(d,l-lactide-co-glycolide)-microspheres

PURPOSE: The purpose of this study was to investigate the process of preparing microspheres for maximising entrapment efficiently (EE) and retained biological activity (RBA) of peptides and proteins. METHODS: A controlled-release formulation based on poly(d,l-lactide-co-glycolide) was designed and produced using a small-scale double emulsion method. These PLG microspheres contained a model peptide, lysozyme. The retained bioactivity of the incorporated lysozyme was determined by bacterial assay. The size distributions and the morphology of the microspheres were characterized. RESULTS: The RBA and EE improved when the PLG concentration in the organic phase of the emulsion was increased. A high lysozyme concentration in the inner water phase of the emulsion resulted in decreased EE and an increase in the proportion of fragmented particles. The RBA of lysozyme in the microspheres varied between 30 and 80% with changes to the process. CONCLUSIONS: The study shows that the RBA of lysozyme in PLG microspheres is strongly dependent on the experimental conditions for preparing the microspheres. Measurement of the EE alone, without the RBA is insufficient to evaluate the efficacy of the designed delivery system.     

The antifungal effect of lactoferrin and lysozyme on Candida krusei and Candida albicans

Lactoferrin and lysozyme (muramidase) are non-immune defence factors present in various exocrine secretions, including saliva. Previous studies have shown that both proteins, either singly or in combination, are bactericidal in nature and their combined activity is synergistic. As little is known of their interactions with Candida species, 20 oral isolates of C. krusei and 5 isolates of C. albicans were studied for their susceptibility to human apo-lactoferrin and lysozyme, either singly or in combination, using an in vitro assay system. The two species exhibited significant interspecies differences in susceptibility to lactoferrin (p < 0.05), but not for lysozyme; C. krusei being more sensitive to lactoferrin (c 1.4 times) than C. albicans. Both species revealed significant intraspecies differences in their susceptibility to lysozyme (p < 0.05), but not for lactoferrin. No synergistic antifungal activity of the two proteins on either Candida species was noted. The results imply that the variable expression of the fungicidal activity of lactoferrin and lysozyme on Candida species may modulate the oral carriage of yeasts in a complex manner.