Activity Of Polymorphonuclear Leukocytes Research Articles

Neutrophil azurophilic granule exocytosis is primed by TNF-α and partially regulated by NADPH oxidase.

Neutrophil (polymorphonuclear leukocyte) activation with release of granule contents plays an important role in the pathogenesis of acute lung injury, prompting clinical trials of inhibitors of neutrophil elastase. Despite mounting evidence for neutrophil-mediated host tissue damage in a variety of disease processes, mechanisms regulating azurophilic granule exocytosis at the plasma membrane, and thus release of elastase and other proteases, are poorly characterized. We hypothesized that azurophilic granule exocytosis would be enhanced under priming conditions similar to those seen during acute inflammatory events and during chronic inflammatory disease, and selected the cytokine TNF-α to model this invitro. Neutrophils stimulated with TNF-α alone elicited intracellular reactive oxygen species (ROS) generation and mobilization of secretory vesicles, specific, and gelatinase granules. p38 and ERK1/2 MAPK were involved in these components of priming. TNF-α priming alone did not mobilize azurophilic granules to the cell surface, but did markedly increase elastase release into the extracellular space in response to secondary stimulation with N-formyl-Met-Leu-Phe (fMLF). Priming of fMLF-stimulated elastase release was further augmented in the absence of NADPH oxidase-derived ROS. Our findings provide a mechanism for host tissue damage during neutrophil-mediated inflammation and suggest a novel anti-inflammatory role for the NADPH oxidase.

Strategic treatment with immunomodulators to resolveendometritis in cow: A review

Postpartum uterine infections result from uterine contamination with bacteria during parturition. The uterine infection implies adherence of pathogenic organisms to the mucosa, colonization or penetration of the epithelium, and release of bacterial toxins that lead to establishment of uterine diseases. Treatment of endometritis with parenteral or intra-uterine infusion of the antibacterial agents and antibiotics have met with varying degree of success but inconsistence of recovery rate, high cost of treatment, milk disposal after antibiotic therapy, immergence of microbial resistance are obvious disadvantage of their use. They also markedly destroy the phagocytic activity of polymorphonuclear leucocytes, which are responsible for maintaining non-specific uterine defence. So, there is urgent need to find out an alternative therapy for treatment of uterine infections by activation of natural defence mechanism in the uterus. Prospects in use of certain non-specific immunomodulators in routine therapeutic protocol for endometritis and other uterine disorders is reviewed in present studies.

Effect of probiotic bacteria on phagocytosis and respiratory burst activity of blood polymorphonuclear leukocytes (PMNL) in mice infected with Trichinella spiralis

This study focusses on the effect of probiotic (bacteriocinogenic) strains on parasite infection and innate immunity – phagocytosis and oxidative burst of blood monocytes and polymorphonuclear leukocytes (PMNL) in mice infected with Trichinella spiralis. Bacteriocinogenic and probiotic strains of different origin (Enterococcus faecium AL41=CCM8558, Enterococcus durans ED26E/7, Lactobacillus fermentum AD1=CCM7421, Lactobacillus plantarum 17L/1) were administered daily in dose of 109CFU/ml in 100μl and mice were infected with 400 larvae of T. spiralis on 7th day of treatment. Phagocytic activity of blood leukocytes was inhibited at week 3 and 4 post infection (p.i.), i.e. in the time of massive muscle invasion with larvae T. spiralis. Administration of bacterial strains to mice prior to T. spiralis infection elevated and prolonged phagocytic activity of blood leukocytes and their ingestion capability from week 1 to 3 of the infection and the phagocytosis was inhibited only at week 4 p.i. The highest stimulative effect on phagocytosis was induced by strains E. durans ED26E/7, L. fermentum AD1=CCM7421, and L. plantarum 17L/1. The percentage of cells with respiratory burst and their enzymatic activity was increased after T. spiralis infection with the exception of week 3 p.i. In contrast, in all mice treated with bacterial strains the enzymatic stimulation was observed after the infection, with the highest intensity caused by strains E. durans ED26E/7, L. fermentum AD1=CCM7421 and L. plantarum 17L/1. The administration of probiotic strains stimulated phagocytosis and respiratory burst of blood PMNL that could contribute to a decreased larval migration and a destruction of muscle larvae and then reduced parasite burden in the host. The protective effect against T. spiralis infection was induced by all strains, but the highest reduction was recorded by E. faecium AL41=CCM8558.

Angiotensin II increases sperm phagocytosis by neutrophils in vitro: A possible physiological role in the bovine oviduct.

This study aimed to investigate the possible effects of the vasoactive peptide angiotensin II (ANG II), secreted by bovine oviduct epithelial cells, on the in vitro phagocytic activity of polymorphonuclear leukocytes, specifically neutrophils, towards sperm. The measured concentrations of ANG II in oviduct flushes and conditioned medium from primary bovine oviduct epithelial culture ranged from 10(-10) to 10(-11) M. In our experiments, neutrophils were incubated for 2 hr with ANG II (0, 10(-11) , 10(-10) , 10(-9) , and 10(-8) M). Phagocytosis and superoxide production were then assessed by co-incubation of these neutrophils with sperm pretreated to induce capacitation, revealing a dose-dependent increase in both metrics by ANG II. This stimulatory effect of ANG II was eliminated by losartan, an angiotensin receptor type 1 (AGTR1) antagonist. ANG II also suppressed neutrophil transcription of angiotensin converting enzyme-1 (ACE) and AGTR1, but not AGTR2, suggesting the involvement of the AGTR1 receptor-mediated pathway in the response to sperm. Scanning electron microscopy further revealed that incubation of neutrophils with ANG II stimulated the formation of DNA-based extracellular traps for sperm entanglement. The addition of prostaglandin E2 at concentrations found in the oviduct suppressed the ANG II-stimulated phagocytic activity of neutrophils towards sperm. Thus the physiological levels of ANG II stimulate neutrophil phagocytosis of sperm in vitro, and suggest that an angiotensin/prostaglandin E2 system may fine-tune the local immune response that fosters sperm survival in the bovine oviduct. Mol. Reprod. Dev. 83: 630-639, 2016. © 2016 Wiley Periodicals, Inc.

Human severe sepsis cytokine mixture increases β2-integrin-dependent polymorphonuclear leukocyte adhesion to cerebral microvascular endothelial cells in vitro.

IntroductionSepsis-associated encephalopathy (SAE) is a state of acute brain dysfunction in response to a systemic infection. We propose that systemic inflammation during sepsis causes increased adhesion of leukocytes to the brain microvasculature, resulting in blood-brain barrier dysfunction. Thus, our objectives were to measure inflammatory analytes in plasma of severe sepsis patients to create an experimental cytokine mixture (CM), and to use this CM to investigate the activation and interactions of polymorphonuclear leukocytes (PMN) and human cerebrovascular endothelial cells (hCMEC/D3) in vitro.MethodsThe concentrations of 41 inflammatory analytes were quantified in plasma obtained from 20 severe sepsis patients and 20 age- and sex-matched healthy controls employing an antibody microarray. Two CMs were prepared to mimic severe sepsis (SSCM) and control (CCM), and these CMs were then used for PMN and hCMEC/D3 stimulation in vitro. PMN adhesion to hCMEC/D3 was assessed under conditions of flow (shear stress 0.7 dyn/cm2).ResultsEight inflammatory analytes elevated in plasma obtained from severe sepsis patients were used to prepare SSCM and CCM. Stimulation of PMN with SSCM led to a marked increase in PMN adhesion to hCMEC/D3, as compared to CCM. PMN adhesion was abolished with neutralizing antibodies to either β2 (CD18), αL/β2 (CD11α/CD18; LFA-1) or αM/β2 (CD11β/CD18; Mac-1) integrins. In addition, immune-neutralization of the endothelial (hCMEC/D3) cell adhesion molecule, ICAM-1 (CD54) also suppressed PMN adhesion.ConclusionsHuman SSCM up-regulates PMN pro-adhesive phenotype and promotes PMN adhesion to cerebrovascular endothelial cells through a β2-integrin-ICAM-1-dependent mechanism. PMN adhesion to the brain microvasculature may contribute to SAE.

Functional activity of neutrophilic polymorphonuclear leukocytes in the first five days postpartum.

To assess the chemotactic activity and phagocytic response of neutrophilic polymorphonuclear leukocytes among women in the first five days postpartum. A prospective, cross-sectional clinical-laboratory study was conducted. Data of 31 postpartum women during the first five days after vaginal delivery were compared with those of 24 healthy non-pregnant non-postpartum women matched for age. The inclusion criteria were postpartum, clinically and obstetrically healthy women; vaginal delivery, singleton pregnancy carried to term; non-hypertensive, hyperglycemic, allergic, malnourished or with autoimmune or neoplastic diseases; not having received vaccines or blood products in the last three months. The Control Group was chosen according to the same inclusion criteria but involving non-pregnant non-postpartum women. The chemotactic activity of neutrophilic polymorphonuclear leukocytes was assessed by determining the distance from directed migration to bacterial lipopolysaccharide, in three Boyden chamber assays. The phagocytic response was identified by assessing the Zymosan particles' ingestion in three assays carried out in Leighton tubes. The Student's t-test was used in the statistical analysis, adopting a 5% level of significance. The chemotactic activity of neutrophilic polymorphonuclear leukocytes from postpartum women in the presence of homologous (73.2 ± 6.9) and autologous (78.6 ± 13.9) sera showed a significant increase compared to the values observed in the Control Group (64.1 ± 4.1 and 66.6 ± 5.4). Both chemotactic response and phagocytosis ingestion phase of neutrophilic polymorphonuclear leukocytes were significantly increased (p < 0.05) in postpartum women compared to healthy non-pregnant and non-postpartum women. There was an increase in the chemotactic activity and phagocytic response of neutrophilic polymorphonuclear leukocytes during the first five days after vaginal delivery in women.

Imipenem, a carbapenem type antibiotic, does not alter pharmacokinetics of a model drug nabumetone

Reported here are the results of a study carried out in order to assess the possible influence of the major circulating active metabolite of nabumetone, 6-methoxy-2-naphthylacetic acid, on some aspects of polymorphonuclear leukocytes activation. The action of 6-methoxy-2-naphthylacetic acid was tested on the following features of polymorphonuclear leukocytes activation: reactive oxygen species production in polymorphonuclear leukocytes stimulated with different agonists, reactive oxygen species production in polymorphonuclear leukocytes treated with pertussis toxin, NADPH-oxidase activity. The findings showed that 6-methoxy-2-naphthylacetic acid decreased reactive oxygen species production in polymorphonuclear leukocytes stimulated with N-formyl-methionyl-leucyl-phenylatanine, phorbol myristate acetate, and opsonized zymosan, but failed to provoke a decrease of reactive oxygen species production when the cells were stimulated with calcium ionophore A23187. Moreover, 6-methoxy-2-naphthylacetic acid did not influence the transduction of the signal following the binding of stimuli to membrane receptors, and NADPH-oxidase activity. Finally, our findings showed that 6-methoxy-2-naphthyl acetic acid had no scavenger effect on reactive oxygen species production.

Neutrophil activation and periodontal tissue injury.

Neutrophilic polymorphonuclear leukocytes (PMNL) track, engage and eliminate foreign entities, including bacteria, fungi and subcellular particles. PMNL are the major host-cell line involved in the acute response during the early stages of infections, including those in the oral cavity. Rather short lived, they are among the fastest moving cells in the human body and travel great distances only to be immolated after encountering and neutralizing antigens. Although their role as the first line of host defense is well established, their role in chronic granulomatous inflammations, diseases and infections remains poorly understood, and many questions on the activation, motility, bactericidity and termination of PMNL in these conditions remain unanswered. This review aims to summarize our current understanding of the molecular mechanisms of PMNL activation and signaling events. Recent evidence indicates the presence of collateral tissue damage caused by poorly regulated PMNL pursuits of periodontal bacteria. Imbalances between the antigenic challenge and the primary host response may augment periodontal tissue breakdown. Thereafter, orchestrated regulation of the resolution of inflammation fails in the presence of a pathogenic periodontal biofilm.

DEGRO practical guidelines for radiotherapy of non-malignant disorders: Part I: physical principles, radiobiological mechanisms, and radiogenic risk.

Synopsis of the introductory paragraph of the DEGRO consensus S2e-guideline recommendations for the radiotherapy of benign disorders, including physical principles, radiobiological mechanisms, and radiogenic risk. This work is based on the S2e-guideline recommendations published November 14, 2013. The basic principles of radiation physics and treatment delivery, evaluation of putative underlying radiobiological mechanisms, and the assessment of genetic and cancer risk following low-dose irradiation will be presented. Radiation therapy of benign diseases is performed according to similar physical principles as those governing treatment of malignant diseases in radiation oncology, using the same techniques and workflows. These methods comprise usage of orthovoltage X-ray units, gamma irradiation facilities, linear accelerators (LINACs), and brachytherapy. Experimental in vitro and in vivo models recently confirmed the clinically observed anti-inflammatory effect of low-dose X-irradiation, and implicated a multitude of radiobiological mechanisms. These include modulation of different immunological pathways, as well as the activities of endothelial cells, mono- and polymorphonuclear leukocytes, and macrophages. The use of effective dose for radiogenic risk assessment and the corresponding tumor incidence rate of 5.5%/Sv are currently controversially discussed. Some authors argue that the risk of radiation-induced cancers should be estimated on the basis of epidemiological data. However, such data are rarely available at present and associated with high variability. Current radiobiological studies clearly demonstrate a therapeutic effectiveness of radiation therapy used to treat benign diseases and implicate various molecular mechanisms. Radiogenic risks should be taken into account when applying radiation treatment for benign diseases.

ENDOGENOUS INTOXICATION AND INFLAMMATION: REACTION SEQUENCE AND INFORMATIVITY OF THE MARKERS (review)

Abstract According to modern phylogenetic theory of general pathology (V.N. Titov, 2003, 2013) inflammation is a nonspecific biological reaction, providing the removal of excessive amount of high-molecular macromolecules and maintenance of metabolic homeostasis (endoecology). The increase of any metabolite concentration above the physiological range is a violation of the «purity» of inter-cellular medium. This triggers two nonspecific biological reactions, namely the excretion used to re-move «biological waste» of a molecular weight less than 70 kD and the inflammation in case the lar-ger molecules and their complexes should be removed via neutrophils, resident macrophages and en-dothelial cells. Blood concentration of leukocytes has been used for evaluation of inflammation and intoxication activity for many decades. However, at the molecular level there is a requirement in precise differentiation of metabolites, activating leukocytes, and metabolites, excessively forming as a result of activation, because the last disturb molecular homeostasis and may damage cells and tissues. Validity of leucocytal intoxication index (LII) of Ya.Ya. Kalf-Kalif, concentration ratio of low and medium molecular weight substances, average molecular peptides, total and effective albumin as markers of endogenous intoxication (M.Ya. Malakhova, 2005) are considered. It is shown that pri-mary agent, activating neutrophils and some factors of humoral immunity, is a lipopolysaccharide (endotoxin) of gram-negative microflora (M.Yu. Yakovlev, 2003; O.W. McIntyre, 2011). An excess of endotoxin inflow is possible under intestine and liver pathologies, and due to sympathoadrenal system activation, and also with feed and air. The overload of systems and organs of elimination of endotoxin causes secondary immunodeficiency, which becomes the cause of acute and chronic in-flammatory processes of various localizations. It is offered to consider lipopolysaccharide of gram-negative microflora as a primary agent of endogenous intoxication and all the metabolites, produces at increased concentrations as a result of polymorphonuclear leukocytes activation such as reactive oxygen species, oxidated proteins, products of lipid peroxidation and proteolysis, as a secondary one. Such an approach allows to single out various points of application for therapy of endogenous intoxi-cation: i) elimination of excessive concentration of lipopolysaccharide in blood by limiting its pro-duction and income from internal and external sources, as well as by a variety of methods of active binding and excretion of endotoxin (S.V. Smirnov et al., 2003; K. Battenschoen et al., 2010); ii) re-ducing the concentration of «secondary» metabolites in blood and tissues. Keywords: endogenous intoxication, segmentated neutrophils, lipopolysaсcharides, inflamma-tion, endotoxinemia, endoecology.

Diminished ROS Production in Neonatal Polymorphonuclear Leukocytes Stimulated with Escherichia coli

Bacterial infection is an important cause of death and long-term morbidity in neonates, especially in immature preterm neonates. The present study clarified the defense mechanism in neonates by measuring superoxide anion (one of reactive oxygen species: ROS) production and phagocytic activity of polymorphonuclear leukocytes (PMNs) caused by live bacterial stimulation in whole blood. In neonatal PMNs, superoxide anion production was significantly diminished when stimulated with an appropriate amount of Escherichia coli (E. coli). There was no significant difference in ROS production with stimulation of Staphylococcus aureus (S. aureus) between adult and neonatal PMNs. Both adult and neonatal PMNs showed equal activity in E. coli phagocytosis. The expression of Toll-Like Receptor 2 (TLR2), Toll-Like Receptor 4 (TLR4) and CD14 on the PMNs showed no difference between neonate and adult blood. The p38 mitogen-activated protein kinase (p38 MAPK) was also activated equally with the stimulation of live bacteria in both PMNs. Since p38 MAPK is a key molecule in lipopolysaccharide binding protein (LBP)-TLR4 mediating intracellular pathway, the receptor mediated signal transduction pathways have no difference between adult and neonatal PMNs. Diminished superoxide production of neonatal PMNs with E. coli stimulation was reconstituted, when neonatal PMNs were stimulated in adult plasma. This phenomenon was abolished by the heat inactivation of adult plasma but not by the addition of anti-interferon γ or anti-tumor necrosis factor α blocking antibody. These data suggest that some heat-labile factors in whole blood might have a role in augmentation of the ROS production of neonatal PMNs, responding to E. coli.

Effects of inactivated Parapoxvirus ovis on polymorphonuclear leukocyte function and myeloperoxidase activity in horses

Immunomodulatory products have been used for years in veterinary medicine. Inactivated Parapoxvirus ovis (iPPVO) is currently used in equine medicine as an immunomodulator to improve the immune system and as a prophylactic treatment to prevent or treat infectious diseases. This study was designed to determine the effects of iPPVO on polymorphonuclear leukocyte (PMNL) function (phagocytosis and intracellular killing activity) and the myeloperoxidase (MPO) activity of PMNLs in horses. Twenty-four healthy English thoroughbred horses with an average age of 11 years were included in the study. Venous blood samples (10 ml) were taken before (agent-free controls) and after the administration of iPPVO (2 ml i.m. injection on Days 1, 3, and 5). PMNLs (1&amp;nbsp;&amp;times;&amp;nbsp;10&lt;sup&gt;7&lt;/sup&gt; cells/ml) were isolated from venous blood containing EDTA (0.1 g/ml) with Ficoll-Hypaque gradient centrifugation. Cellular phagocytosis and intracellular killing activities were assayed using a modification of Alexander&amp;rsquo;s method before and after treatment with iPPVO. MPO activity was also measured. The administration of iPPVO significantly increased the phagocytic, intracellular killing, and MPO activities of equine PMNLs (P = 0.0058, P&amp;nbsp;= 0.0050, and P = 0.0070, respectively). This study demonstrates a strong correlation between MPO activity and PMNL function. The administration of iPPVO to horses has a supportive effect on their cellular immunity and an immunomodulatory effect against equine viral infections.

Role of Advanced Glycation End Products and Its Receptors in the Pathogenesis of Cigarette Smoke-Induced Cardiovascular Disease.

The interaction of advanced glycation end products (AGEs) with its cell-bound receptor RAGE increases gene expression and release of proinflammatory cytokines and increase generation of reactive oxygen species (ROS). Circulating receptors, soluble RAGE (sRAGE), and endosecretory RAGE (esRAGE) by binding with RAGE ligands have protective effects against AGE-RAGE interaction. Cigarette smoking is a risk factor for coronary artery disease, stroke, and peripheral vascular disease. This article reviews; if the AGE-RAGE axis is involved in the cigarette smoke-induced cardiovascular diseases. There are various sources of AGEs in smokers including, gas/tar of cigarette, activation of macrophages and polymorphonuclear leukocytes, uncoupling of endothelial isoform of nitric oxide synthase (eNOS) and xanthine oxidase. The levels of AGEs are elevated in smokers. Serum levels of sRAGE have been reported to be reduced, elevated, or unchanged in smokers. Mostly the levels are reduced. There is one article which shows an elevation of levels of sRAGE in smokers. Serum levels of esRAGE are unaltered in smokers. Mechanism of AGE-RAGE-induced atherosclerosis has been discussed. Atherosclerosis leads to the cardiovascular diseases. It has been suggested that ratio of AGE/sRAGE or AGE/esRAGE is useful in determining the deleterious effects of AGE-RAGE interaction in smokers. sRAGE alone is not a good marker for smoke-induced cardiovascular disease. In conclusion cigarette smoke induces formation of AGEs and reduces sRAGE resulting in the development of atherosclerosis and related coronary heart disease, stroke, and peripheral vascular disease. Ratio of AGEs/sRAGE is a better marker for cardiovascular disease than AGEs or sRAGE alone in smokers.

Assessment and comparison of phagocytic function and viability of polymorphonuclear leukocytes in saliva of smokers and non-smokers

OBJECTIVESTobacco use is one of the most important public health problems worldwide. It is also linked to impairment of normal immunologic surveillance and defence mechanism of polymorphonuclear leukocytes. Tobacco smoke and its components have been seen to affect the phagocytic ability and viability of polymorphonuclear leukocytes suggesting the pathogenesis of tobacco induced oral diseases. Aim of this study was to assess and compare the phagocytic function and viability of polymorphonuclear leukocytes in saliva of smokers and non smokers. DESIGNThe study comprised of 35 smokers and 35 non-smokers, age matched. Saliva was collected by rinsing method and the polymorphonuclear leukocytes were separated. Phagocytic activity was determined by using latex spheres as targets. Cell viability was measured using trypan blue stain. RESULTSSalivary polymorphonuclear leukocytes in smokers showed significant reduction in the phagocytic activity by ingesting few latex spheres when compared to the non-smokers. The viability of these cells in saliva of smokers was significantly reduced. CONCLUSIONSThe present study revealed reduced phagocytic activity and viability of salivary polymorphonuclear leukocytes in smokers compared to non-smokers. These findings indicate that smokers are more prone to gingival, periodontal and other oral diseases. Thus indicating that the health care professionals should encourage smoking cessation as an aid in preventing oral diseases.

Enhanced expression of aquaporin 9 in activated polymorphonuclear leukocytes in patients with systemic inflammatory response syndrome.

Aquaporins (AQPs) are water channels of cell membranes. All living cells experience osmotic pressure changes in their environment, but the mechanism by which water influx occurs was not known until the discovery of AQPs. AQP9, which is expressed in human polymorphonuclear leukocytes (PMNLs), is reported to relate to morphologic changes of PMNLs in vitro. We examined the expression of AQP9 in PMNLs from patients with systemic inflammatory response syndrome (SIRS) and addressed the role of AQP9 in both morphologic and functional changes of PMNLs in the SIRS condition. Fourteen patients with SIRS were included in our study. Polyclonal antibody was used for the AQP9 assay. F-actin polymerization, oxidative activity, and the expression of AQP9 in PMNLs with and without stimulation by N-formylmethionyl-leucyl-phenylalanine were evaluated by flow cytometry. Expression of AQP9, F-actin polymerization, and oxidative activity in PMNLs were increased significantly in patients with SIRS compared with those in healthy volunteers. The time course of AQP9 fluorescence in PMNLs corresponded to the time course of F-actin polymerization, which showed peak fluorescence at 1 min after N-formylmethionyl-leucyl-phenylalanine stimulation. The expression of AQP9 in PMNLs is increased significantly in SIRS patients. The increased expression of AQP9 in SIRS patients might be associated with F-actin polymerization in PMNLs, which could affect both morphologic and functional changes of PMNLs in the SIRS condition.

Immunity, gut microbiota and infection

Recurrent infections are very common in children and a major challenge for pediatricians. They affect the children’s quality of life, cause absences from school and lost parental working days, and repeated medical examinations, hospital admissions as well as antibiotic therapies lead to high costs for society. Given their prevalence and clinical importance, various prevention strategies have been developed. Some of these strategies have considered that innate and adaptive immunity are strictly related with gut microbiota and interact in the modulation of host’s reactivity to infections. Variations in gut microbiota related to age, nutrition or underlying disease may influence immune system defenses against viruses and bacteria. Furthermore, disturbed gut colonization patterns are proposed to be associated with the development of allergic disease. This explains why probiotics represent an important option in the prophylaxis and the management of recurrent infectious diseases as well as allergic diseases. However, the incomplete understanding of what constitutes a healthy gut microbiota that promotes tolerance, remains a challenge. Further understanding of gut microbial functions may pave the way for more effective prevention and treatment strategies. Another approach used for prevention of recurrent infections is represented by the administration of immunostimulants: i.e. molecules of bacterial or synthetic origin that interact with immunological mechanisms in vitro and in vivo. Pidotimod (3-L-pyroglutamil-L-thiaziolidine-4-carboxylic acid) is a synthetic dipeptide which stimulates the phagocytic activity of polymorphonuclear leukocytes, enhances the killing activity of human alveolar macrophages, increases the cytotoxic activity of natural killer cells, and stimulates cytokine production. It also influences the maturation and activity of dendritic cells by increasing the expression of the key surface markers that help to trigger T cell activation and increased IL-12 production. The majority of studies have shown that the number of infections decreases after pidotimod treatment, but they are affected by some methodological weaknesses. Further studies are urgently needed to confirm the pediatric population that should have the greatest benefit with the administration of immunostimulants. More studies are needed to identify the most promising probiotic strains and study populations, and to evaluate the mechanisms behind the possible effects of probiotics on OM.

Leukocyte deformability is a novel biomarker to reflect sepsis-induced disseminated intravascular coagulation.

Sepsis-induced disseminated intravascular coagulopathy is associated with a high mortality rate. The function and deformability of polymorphonuclear leukocytes change in patients with sepsis. The goal of this study was to characterize the changes in polymorphonuclear leukocyte deformability in patients with sepsis-induced disseminated intravascular coagulopathy and to evaluate the relationship between the severity of disseminated intravascular coagulopathy and the deformability of polymorphonuclear leukocytes. Thirty-five patients with sepsis-induced disseminated intravascular coagulopathy at our department were enrolled in this study. These patients were diagnosed with severe sepsis and an acute disseminated intravascular coagulopathy score ≥ 4. Blood samples were obtained from these patients on days 1, 3, and 7. Polymorphonuclear leukocyte deformability was measured with a microchannel flow analyzer, and polymorphonuclear leukocyte activity, represented as CD11b, was measured by flow cytometry. In contrast, 14 patients who fulfilled with sepsis criteria but without complicated disseminated intravascular coagulopathy were also entered in this study. In patients with sepsis-induced disseminated intravascular coagulopathy, there was a significant correlation between their Japanese Association for Acute Medicine disseminated intravascular coagulopathy score and polymorphonuclear leukocyte deformability, and CD11b expression. Polymorphonuclear leukocytes became more stiffened and CD11b expression was higher in patients with sepsis-induced disseminated intravascular coagulopathy compared to patients without the condition. Polymorphonuclear leukocyte deformability correlated with the severity of sepsis-induced disseminated intravascular coagulopathy and the response to treatment.

Effects of S. officinalis L. radix triterpene glycosides on innate immunity factors.

The effects of triterpene glycosides (saponins) extracted from Saponaria officinalis L. radices, on the cellular and humoral innate immunity factors were studied. Saponins stimulated the phagocytic, bactericidal, and adhesion activities of polymorphonuclear leukocytes. Optimal conditions of saponin treatment (dose and duration) were determined for mice. Saponins promoted the maturation of human peripheral blood dendritic cells, which was proven by high expression of CD83 (terminal differentiation marker) and CD86 (bone-stimulating molecule) and of HLA-DR and HLA-ABC molecules on the cell membrane. Saponins modulated the production of TNF-α, IL-1β, IL-4, IL-6, and IFN-γ in cultured peripheral blood intact cells. The results help to understand some mechanisms of the effects of saponins extracted from Saponaria officinalis L. radix on the cellular and humoral factors of innate immunity and demonstrate good prospects of their practical use.

Prevention of Late PJI

The definition of late PJI is variable in literature. Majority of the members of the consensus felt that any infection occurring after one year should be considered as late. Coventry defined stages of PJI, where Stage I is an acute infection that occurred within 3 months of the index procedure, Stage II is a delayed infection that occurred between 3 months and 2 years after the index procedure where there was no pain-free interval, and Stage III is a hematogenous infection where there is a pain-free stage [1]. Garvin and Hanssen defined a late chronic PJI as one that occurred 4 weeks after the index procedure with an insidious clinical onset [2]. McPherson et al defined a chronic infection as one that had symptoms for 4 weeks or longer [3]. In Sweden, a late PJI is defined as one that occurs 2 years after the index procedure. Due to the huge variation in time frames, we did not find consensus in defining a timeframe for a late PJI. However, we classified late PJI as late hematogenous PJI, where there was an asymptomatic period followed by clinical and/or radiographical signs of infection. The workgroup feels that late PJI arises as a result of bacteremia at a later stage [4] and should be distinguished with infections arising as a result of intraoperative contamination. Risk factors for late PJI are similar to those described for PJI in Workgroup 1 (Please see Question 1, Workgroup 1).

Time course of systemic oxidative stress and inflammatory response induced by an acute exposure to Residual Oil Fly Ash

It is suggested that systemic oxidative stress and inflammation play a central role in the onset and progression of cardiovascular diseases associated with the exposure to particulate matter (PM). The aim of this work was to evaluate the time changes of systemic markers of oxidative stress and inflammation, after an acute exposure to Residual Oil Fly Ash (ROFA). Female Swiss mice were intranasally instilled with a ROFA suspension (1.0mg/kg body weight) or saline solution, and plasma levels of oxidative damage markers [thiobarbituric acid reactive substances (TBARSs) and protein carbonyls], antioxidant status [reduced (GSH) and oxidized (GSSG) glutathione, ascorbic acid levels, and superoxide dismutase (SOD) activity], cytokines levels, and intravascular leukocyte activation were evaluated after 1, 3 or 5h of exposure. Oxidative damage to lipids and decreased GSH/GSSG ratio were observed in ROFA-exposed mice as early as 1h. Afterwards, increased protein oxidation, decreased ascorbic acid content and SOD activity were found in this group at 3h. The onset of an adaptive response was observed at 5h after the ROFA exposure, as indicated by decreased TBARS plasma content and increased SOD activity. The observed increase in oxidative damage to plasma macromolecules, together with systemic antioxidants depletion, may be a consequence of a systemic inflammatory response triggered by the ROFA exposure, since increased TNF-α and IL-6 plasma levels and polymorphonuclear leukocytes activation was found at every evaluated time point. These findings contribute to the understanding of the increase in cardiovascular morbidity and mortality, in association with environmental PM inhalation.