Related Inflammatory Mediators Research Articles

Inhibitory effect of MIL glycoprotein on expression of pro‐inflammatory mediators in carbon tetrachloride‐induced mice liver damage

The aim of the present study was to evaluate immunomodulatory and hepatoprotective effects of glycoprotein isolated from Morus indica Linne (MIL glycoprotein) on carbon tetrachloride (CCl(4) )-induced liver injury. In the present study, MIL glycoprotein (5 and 10 mg kg(-1) body weight) was administered to ICR mice for 7 days prior to CCl(4) treatment. We evaluated the activities of alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and thiobarbituric acid-reactive substances (TBARS), and expression of inflammation-related mediators including cyclooxygenase (COX)-2, tumor necrosis factor (TNF)-α, and interleukin (IL)-1 beta in CCl(4) -treated mice. Our results revealed that MIL glycoprotein reduced the activities of ALT, LDH and TBARS in serum from CCl(4) -treated mice. We also found that MIL glycoprotein reduced the activity of COX-2 and expression of TNF-α and IL-1 beta in liver from CCl(4) -treated mice. Moreover, administration of MIL glycoprotein suppressed on stress-activated protein kinase/c-jun N-terminal kinase phosphorylation and activator protein-1 transcriptional activation in livers from CCl(4) -treated mice. The results from these experiments indicate that MIL glycoprotein effectively protects against liver injury, mainly through downregulation of oxidative stress and the inflammatory response. In conclusion, we suggest that the MIL glycoprotein might be one component of health supplements for prevention of liver diseases.

32P‐postlabeling analysis of DNA adducts formed by leukotriene A4 (LTA4)

Leukotriene A(4) (LTA(4)), a reactive electrophilic intermediate formed during the biosynthesis of inflammation-related lipid mediators, has been found to bind covalently to DNA. The major DNA adducts formed by LTA(4) in vitro and human cells have been identified by mass spectrometry on the nucleoside level. Here we investigated whether the thin-layer chromatography (TLC) (32)P-postlabeling method is suitable for the detection of LTA(4)-DNA adducts. The reaction of individual deoxynucleoside 3'-monophosphates with LTA(4) in aqueous basic solution yielded numerous adduct spots when analyzed by the two enrichment procedures of the (32)P-postlabeling method-nuclease P1 digestion and butanol extraction. Highest LTA(4)-adduct levels were found with deoxyguanosine 3'-phosphate (around one adduct per 10(4) normal nucleotides). Under similar reaction conditions LTA(4) (25-320 microM) was incubated with calf thymus DNA, then DNA adduct patterns and levels were determined with the TLC (32)P-postlabeling method using both enrichment versions. The same DNA adduct pattern consisting of up to seven spots was observed with both enrichment versions. DNA adduct formation by LTA(4) was concentration-dependent with major adducts being derived from deoxyguanosine. When a human monocytic cell line (Mono Mac 6) was stimulated with arachidonic acid and calcium ionophore LTA(4)-DNA adducts were detected by (32)P-postlabeling. However, the level of these endogenously formed DNA adducts was close to the detection limit (3 +/- 2 adducts per 10(8) normal nucleotides). In summary, the TLC (32)P-postlabeling method is suitable for studying DNA adduct formation by LTA(4) and can be used for further investigations on the link between inflammation and cancer.

Effects of dietary fish oil supplementation on cellular adhesion molecule expression and tissue myeloperoxidase activity in hypercholesterolemic mice with sepsis

This study investigated the effects of fish oil on adhesion molecule expression and tissue myeloperoxidase (MPO) activity in hypercholesterolemic mice with sepsis. There were one control and two experimental groups in this study. The control group (C) was fed a regular chow diet for 7 weeks, while hypercholesterolemia in the experimental group was induced by feeding a high-fat diet (20%, w/w) with cholesterol (2%, w/w) for 4 weeks. Then the experimental group was divided into two subgroups with identical nutrient distributions except that one subgroup was fed soybean oil (SO), while part of the soybean oil was replaced by fish oil (FO) in the other one for 3 weeks. After feeding the diets for 7 weeks, sepsis was induced in all three groups by cecal and ligation and puncture (CLP), and mice were sacrificed at 0, 6 or 24 h after CLP, respectively. The results showed that the FO group had a higher intracellular interferon-γ/interleukin-4 ratio and lower tumor necrosis factor-α and monocyte chemoattractant protein-1 concentrations in peritoneal lavage fluid at 6 h after CLP than those in the C and SO groups. Lymphocyte CD11a/CD18 expressions were higher at 0 and 6 h and neutrophil CD11b/CD18 were higher at 6 h in the SO group than in the FO and C groups. The SO group had higher plasma intercellular adhesion molecule (ICAM)-1 levels than C group at 0 and 6 h, whereas no difference in ICAM-1 concentrations were observed between the C and FO groups at 0 h after CLP. Hypercholesterolemia resulted in higher tissue MPO activities. There were no differences in MPO activities in various organs between the two experimental groups. These results suggest that hypercholesterolemic mice fed FO did not exhibit immunosuppression when complicated with sepsis. FO administration reduced adhesion molecule expressions and inflammatory-related mediators at the site of injury at an early but not a late stage of sepsis. However, compared with the SO group, the influences of FO on MPO activities in various organs were not obvious in hypercholesterolemic mice with sepsis.

Influence of Age and Gender on Cytokine Expression in a Murine Model of Parkinson’s Disease

Objective: The neuroinflammatory reaction has been linked with Parkinson’s disease. One of the hypotheses to explain the significance of age and gender (male predominance) effects on neurodegeneration in Parkinson’s disease may result from a link between these risk factors and the inflammatory processes. Here, we investigated the expression of inflammatory mediators in relation to 1-methyl-4-phenyl-1,2,3,6-tetrahydropiridine (MPTP)-induced neurodegenerative processes in nigrostriatal pathway in young and aged male and female mice.Methods and Results: We simultaneously assessed striatal tyrosine hydroxylase (TH) protein concentrations (Western blotting) and cytokine (TNFα, IFNγ, IL-1β, IL-6 and TGFβ₁) mRNA levels (RT-PCR) in young and aged (2- and 12-month-old) C57BL/6 male and female mice after 6 h, 1, 3, 7, 14, 21 days after MPTP intoxication.Western blotting analysis showed that at the early time points, males showed a greater reduction in striatal TH versus females. Additionally, in contrast to the aged mice, in young males and females the TH concentration gradually increased between the 7th and the 21st day after intoxication. The increases in TNFα, IL-1β and IFNγ after intoxication were faster in both young and aged males than females. In males (both ages), we observed an increase in TGFβ₁ at the early time points. In contrast, in females (both ages) TGFβ₁ was elevated at later time points. MPTP caused an increase in IL-6 in males and females, but this increase was significantly higher in females. Conclusions: A gender and age skewing of the cytokine gene expression in the striatum after intoxication may be related to the greater susceptibility in males as well as older animals to the detrimental effects of MPTP.

Role of Cytokines during Epileptogenesis and in the Transition from the Interictal to the Ictal State in the Epileptic Mutant EL Mouse

Purpose Epileptic mutant EL mice show secondary generalized seizures. Seizure discharges initiate in the parietal cortex and generalize through the hippocampus. We have previously demonstrated an increase in the activity of inducible nitric oxide synthetase (iNOS) as well as a decrease in the activity of superoxide dismutase (SOD) in the hippocampus of EL mice, suggesting that cell toxic free radicals are increased in the brain of EL mice. In parallel with this, neurotrophic factors were significantly increased in the hippocampus of EL mice in earlier developmental stages before exhibiting frequent seizures. These findings were no longer present after frequent seizures, suggesting that these events may trigger ictogenesis. On the other hand, it is reported that limbic seizures rapidly induce cytokines and related inflammatory mediators. It remains to be seen, however, whether cytokines contribute to the transition from interictal to ictal state. The present study was designed to address this issue using EL mice. Methods EL mice at the age from 4 to 23 weeks and their control animal, DDY mice at the age of 10 and 20 weeks were used. Seizures were induced in EL mice once every week since 5 weeks. Cytokines, such as interleukin-1 alpha (IL-1a), interleukin 1-beta (IL-1b), IL-6, IL-1 receptor (IL-1r), IL-1 receptor antagonist (IL-ra) and tumor necrosis factor alpha (TNF-a) were examined by Western blotting in the ‘focus complex’ of brain (namely, in the parietal cortex and hippocampus) of EL mice in the interictal period at different developmental stages. In 15 week old EL mice, which show seizures once a week, these cytokines were similarly determined 5 min, 2 hr, 4 hr, 11 hr, 24 hr, 3 days and 6 days after the last seizure induced. Results A significant increase in the level of cytokines was observed in the brain of EL mice at any stages during development, compared with the level of cytokines in the brain of control DDY. Cytokines were increased predominantly before experiencing frequent seizures. In EL mice at the age of 15 weeks, the level of cytokines in the hippocampus was highest 6 days after seizures. In the parietal cortex, cytokines were most highly expressed 2 hr after seizures. The results indicate that cytokines were kept up-regulated until next seizures in the hippocampus, whereas they were transiently up-regulated immediately after seizures in the parietal cortex. Conclusion It is concluded that in the brain of EL mice, pro-inflammatory cytokines are increased progressively and periodically in association with the development and the seizure activity, respectively. A periodic increase of cytokines prior to the next seizure episode may play a role in triggering the ictal activity. Namely, alteration of region-specific cytokines may induce ictal activities from the interictal state. It is conceivable that inflammatory cytokines may work together with neuronal factors during epileptogenesis and in the transition from interictal to ictal state.

Arthrofibrosis of the Knee

Better understanding of surgical timing, improved surgical technique, and advanced rehabilitation protocols has led to decreased incidence of motion loss after anterior cruciate ligament injury and reconstruction. However, motion loss from high-energy, multiligament injuries continues to compromise functional outcome. Prevention, consisting of control of inflammation and early motion, remains the key element in avoiding motion loss. However, certain techniques, such as manipulation under anesthesia in conjunction with arthroscopic lysis of adhesions, are reliable treatment options. Open surgical débridement is rarely necessary and should be considered only as a salvage procedure. A greater understanding of the pathogenesis of arthrofibrosis and related inflammatory mediators may result in novel therapies for treating the patient with motion loss.

In vivo kinetics of cytokine expression during peritonitis in carp: Evidence for innate and alternative macrophage polarization

Despite the discovery of many cytokine genes in fish, knowledge on their functional homology is limited. To enlighten the biological function of inflammation-related mediators, we studied their kinetics of gene expression during peritonitis in carp. Zymosan-induced intraperitoneal influx of phagocytes reached a maximum at 24 h. In peritoneal leukocytes (PTL) up-regulation of IL-1 β, TNF- α, CXCa, and chemokine receptor CXCR1 preceded this peak. Delayed up-regulation of these genes in the head kidney (HK) indicates emigration of antigen-presenting cells from peritoneum into HK and/or systemic spreading of inflammation. In turn, early increase in expression of anti-inflammatory genes in HK (6 h) precede their up-regulation in the focus of inflammation. In PTL peaks of IL-10 and arginase 2 expression were recorded at 96 and 168 h, respectively. These results give evidence that carp macrophages in vivo differentiate into a continuum of different activation states with innate and alternative activation representing the extremes.

Anthocyanins Inhibit Nuclear Factor-κB Activation in Monocytes and Reduce Plasma Concentrations of Pro-Inflammatory Mediators in Healthy Adults , ,3

The transcription factor nuclear factor-κB (NF-κB) is activated by oxidative stress and pro-inflammatory stimuli and controls the expression of numerous genes involved in the inflammatory response. Dampening NF-κB activation and thereby limiting the inflammatory response have been suggested as a potential strategy to prevent chronic inflammatory diseases. In cultured monocytes, anthocyanins isolated from bilberries and black currants (Medox) efficiently suppressed LPS-induced activation of NF-κB. Furthermore, we studied the effect of anthocyanin supplementation (Medox, 300 mg/d for 3 wk) in a parallel-designed, placebo-controlled clinical trial (n = 120 men and women aged 40–74 y). Differences were observed in several NF-κB related inflammatory mediators in the Medox group compared to placebo. The changes in the NF-κB-controlled pro-inflammatory chemokines IL-8, “regulated upon activation, normal T cell expressed and secreted,” (RANTES) and IFNα (an inducer of NF-κB activation) in the Medox group (45, 15, and 40% decreases from baseline, respectively) differed from those in the placebo group (20, 0, and 15% decreases from baseline, respectively) (P < 0.050). Similarly, changes in IL-4 and IL-13, 2 cytokines that mediate pro-inflammatory responses and induce NF-κB activation, in the Medox group (60 and 38% decreases from baseline, respectively) tended to differ from those in the placebo group (4 and 6% decreases) (P = 0.056 and, P = 0.089, respectively).These data suggest that anthocyanin supplementation may have a role in the prevention or treatment of chronic inflammatory diseases by inhibition of NF-κB transactivation and deceased plasma concentrations of pro-inflammatory chemokines, cytokines, and inflammatory mediators.

Differential accumulation of pulmonary and cardiac mast cell-subsets and eosinophils between fatal anaphylaxis and asthma death: A postmortem comparative study

The distribution profile of infiltrated mast cell-subpopulations and eosinophils in the lung and heart sections of the patients who died of severe allergic hyperresponsiveness, was investigated. Four study groups were designed comprising 9 cases who died in systemic anaphylaxis (Group I), 10 asthmatic individuals whose death were assigned to acute and severe bronchial asthma (Group II), 10 asthmatic cases who died from non-immunological diseases (Group III). Twenty consecutive autopsies of non-allergic subjects who died of unnatural causes (Group IV) served as control group in this study. Utilizing antibodies against human tryptase and chymase and a double immunohistochemical staining method, we distinguished successfully all three subsets of mast cells (MC), MC-TC (containing both tryptase and chymase), MC-T (containing only tryptase) and MC-C (containing only chymase) types, subdivided on the basis of the protease compositions of their secretory granules. In order to immunostaining eosinophils, we used antibody to major basic protein as a marker. We also measured postmortem blood tryptase, specific and total serum IgE. The intriguing finding of this study was the marked differences of cellular composition in the lung between fatal anaphylaxis and asthma death. Significant augmentation of MCs infiltrated in lung and heart sections of anaphylaxis patients and drastic infiltration of bronchial eosinophils in asthmatic death and consequent release of their related inflammatory mediators might explain the differential expression of the associated symptoms in these two groups. The anaphylactic deaths did show neither emphysema nor significant mucous bronchial secretions whereas all asthmatic deaths did. The degree of pulmonary congestion and edema was also more severe in anaphylaxis. This corresponded with the histological findings and the location and number of mast cell-subsets and eosinophils in the different compartments of the lungs. We have demonstrated that the third type of mast cell MC-C is only found in the lungs in anaphylactic deaths. The practical consequence of our study will be that it is now possible to confirm a suspicion of anaphylaxis death not only by measurements of serum mast cell tryptase, but also by immunohistochemical methods.

Inactivation of Caspase‐1 in Rodent Brain: A Novel Anticonvulsive Strategy

Cytokines and related inflammatory mediators are rapidly synthesized in the brain during seizures. We previously found that intracerebral administration of interleukin-1 (IL-1)-beta has proconvulsant effects, whereas its endogenous receptor antagonist (IL-1Ra) mediates potent anticonvulsant actions in various models of limbic seizures. In this study, we investigated whether seizures can be effectively inhibited by blocking the brain production of IL-1beta, by using selective inhibitors of interleukin-converting enzyme (ICE/caspase-1) or through caspase-1 gene deletion. Caspase-1 was selectively blocked by using pralnacasan or VX-765. IL-1beta release was induced in mouse organotypic hippocampal slice cultures by proinflammatory stimuli [lipopolysaccharide (LPS) + adenosine triphosphate (ATP)] and measured with enzyme-linked immunosorbent assay (ELISA). IL-1beta production during seizures was measured in the rat hippocampus by Western blot. Seizures were induced in freely moving mice and rats by intrahippocampal injection of kainic acid and recorded by EEG analysis. Caspase-1 inhibition reduced the release of IL-1beta in organotypic slices exposed to LPS+ATP. Administration of pralnacasan (intracerebroventricular, 50 microg) or VX-765 (intraperitoneal, 25-200 mg/kg) to rats blocked seizure-induced production of IL-1beta in the hippocampus, and resulted in a twofold delay in seizure onset and 50% reduction in seizure duration. Mice with caspase-1 gene deletion showed a 70% reduction in seizures and an approximate fourfold delay in their onset. Inhibition of caspase-1 represents an effective and novel anticonvulsive strategy, which acts by selectively reducing the brain availability of IL-1beta.

Effect of Aerosolized Docosahexaenoic Acid in a Mouse Model of Atopic Asthma

Background: Docosahexaenoic acid (DHA) found in fish oil is known to depress inflammation-related mediators. We investigated a novel delivery method of tridocosahexaenoyl-glycerol (DHA-TG). Methods: BALB/c mice (6–8 weeks old) were primed intraperitoneally with ovalbumin (OVA) and Al(OH)₃ on days 0 and 7, and with aerosolized OVA on day 7. Primed mice were challenged by repeated exposure to aerosolized OVA on days 15–17. Just before each exposure to aerosolized OVA, the mice were also exposed to an aerosol of emulsified DHA-TG or soybean oil, or saline (days 7 and 15–17). Bronchial hyperresponsiveness (BHR) to methacholine was measured, and bronchoalveolar lavage fluid was obtained 24 h after the last challenge (day 18). Lungs were histologically examined. Results: Bronchoalveolar lavage fluid of saline-treated mice showed an increased cellularity with predominant eosinophils. Exposure to DHA-TG significantly reduced the total cell number and the eosinophil percentage in lavage fluid, whereas soybean oil did not. Conclusion: DHA but not soybean oil exposure reduced BHR and cell infiltration to bronchovascular bundles. This type of DHA administration could be studied in clinical trials.

Effects of dietary fish oil on survival rate, plasma amino acid pattern, and inflammatory-related mediators in diabetic rats with sepsis

This study was designed to investigate the effects of dietary fish oil on survival rates, plasma amino acid profiles, and inflammatory-related mediators in diabetic rats with sepsis. Diabetes mellitus (DM) was induced in rats by streptozotocin. The DM rats were maintained for 4 weeks on medium fat (10%, w/w) diets containing either fish oil or safflower oil. After that, sepsis was induced by cecal ligation and puncture (CLP). There were 2 groups in this study: fish oil sepsis group (FOS) and safflower oil sepsis group (SOS). The survival rate was observed after CLP. Also, changes of the amino acid pattern as well as interleukin (IL)-1β, tumor necrosis factor (TNF)-α, prostaglandin (PG) E2at 6, 12, and 24 h after CLP were investigated. The results demonstrated that survival rates were not significantly different between the 2 groups. Plasma arginine levels were significantly lower in sepsis groups than that in the DM-chow group, regardless of whether the diabetic rats were fed fish oil or safflower oil. No significant differences were observed in plasma valine, leucine, isoleucine, glutamine, or arginine concentrations between the FOS and SOS groups at different time points. Concentrations of IL-1β in peritoneal lavage fluid (PLF) at 6 h and TNF-α at 6 h as well as at 12 h after CLP in the FOS group were significantly higher than those in the SOS group. PGE2levels in PLF, by contrast, were lower in the FOS group at 6 and 12 h after CLP than in the SOS group. These results suggest that differences in IL-1β, TNF-α, and PGE2levels in PLF in the early period of sepsis did not influence the survival rates and plasma amino acid profiles of the FOS and SOS groups. Compared with safflower oil, feeding diabetic rats with fish oil had no beneficial effects on survival rates and muscle protein breakdown. The immunologic impact of dietary n-3 polyunsaturated fatty acids on diabetic rats with sepsis requires further investigation.

Effects of parenteral infusion with fish-oil or safflower-oil emulsion on hepatic lipids, plasma amino acids, and inflammatory mediators in septic rats

This study was designed to investigate the effects of preinfusion with total parenteral nutrition (TPN) using fish-oil (FO) versus safflower-oil (SO) emulsion as fat sources on hepatic lipids, plasma amino-acid profiles, and inflammatory-related mediators in septic rats. Normal rats, with internal jugular catheters, were assigned to two different groups and received TPN. TPN provided 300 kcal · kg −1 · d −1, with 40% of the non-protein energy as fat. All TPN solutions were isonitrogenous and identical in nutrient composition except for the fat emulsion, which was made of SO or FO. After receiving TPN for 6 d, each group of rats was further divided into control and sepsis subgroups. Sepsis was induced by cecal ligation and puncture; control rats received sham operation. All rats were classified into four groups as follows: FO control group (FOC; n = 7), FO sepsis group (FOS; n = 8), SO control group (SOC; n = 8), and SO sepsis group (SOS; n = 9). The results of the study demonstrated that plasma concentrations of triacylglycerol and non-esterified fatty acids did not differ between the FO and SO groups, regardless of whether the animals were septic. SOS had significantly higher total lipids and cholesterol content in the liver than did the SOC group. The FOS group, however, showed no difference from the FOC group. Plasma leucine and isoleucine levels were significantly lower in the SOS group than in the SOC group, whereas no difference in these two amino acids was observed between the FOC and FOS groups. Plasma arginine levels were significantly lower in both septic groups than in the groups without sepsis when either FO or SO was infused. Plasma glutamine levels, however, did not differ across groups. No differences in interleukin-1β, interleukin-6, tumor necrosis factor-α, or leukotriene B 4 concentrations in peritoneal lavage fluid were observed between the two septic groups. These results suggest that catabolic reaction in septic rats preinfused with FO is not as obvious as those preinfused with SO. Compared with SO emulsion, TPN with FO emulsion prevents liver fat accumulation associated with sepsis. However, parenterally administered FO had no beneficial effect in lowering cytokines and LTB 4 levels in peritoneal lavage fluid in septic rats induced by cecal ligation and puncture.

Effects of parenteral infusion with medium-chain triglycerides and safflower oil emulsions on hepatic lipids, plasma amino acids and inflammatory mediators in septic rats

This study was designed to investigate the effects of preinfusion with total parenteral nutrition (TPN) using medium-chain triglycerides (MCT) versus safflower oil (SO) emulsion as fat sources on hepatic lipids, plasma amino acid profiles, and inflammatory-related mediators in septic rats. Normal rats, with internal jugular catheters, were divided into two groups and received TPN. TPN provided 300kcal/kg/day with 40% of the non-protein energy provided as fat. All TPN solutions were isonitrogenous and identical in nutrient composition except for the fat emulsion, which was made of SO or a mixture of MCT and soybean oil (9:1) (MO). After receiving TPN for 6 days, each group of rats was further divided into control and sepsis subgroups. Sepsis was induced by cecal ligation and puncture, whereas control rats received sham operation. All rats were classified into four groups as follows: MCT control group (MOC, n= 8), MCT sepsis group (MOS, n= 8), safflower oil control group (SOC, n= 8), and safflower oil sepsis group (SOS, n= 11). The results of the study demonstrated that the MOS group had lower hepatic lipids than did the SOS group. Plasma leucine and isoleucine levels were significantly lower in the SOS than in the SOC group, but no differences in these two amino acids were observed between the MOC and MOS groups. Plasma arginine levels were significantly lower in septic groups than in those without sepsis despite whether MCT or safflower oil was infused. Plasma glutamine and alanine levels, however, did not differ between septic and non-septic groups either in the SO or MO groups. No differences in interleukin-1b, interleukin-6, tumor necrosis factor-α, and leukotriene B4concentrations in peritoneal lavage fluid were observed between the two septic groups. These results suggest that catabolic reaction is septic rats preinfused MCT is not as obvious as those preinfused safflower oil. Compared with safflower oil, TPN with MCT administration has better effects on reducing sepsis-induced liver fat deposition. Preinfusion with MCT before sepsis, however, had no effect on inflammatory-related cytokines or leukotriene in peritoneal lavage fluid. In addition, plasma arginine appears to be a more sensitive indicator than glutamine for septic insult.

New drugs for the treatment of rheumatoid arthritis.

New pharmacologic treatment options for rheumatoid arthritis (RA) are described. Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely prescribed for RA but are limited by the risk of adverse effects, especially gastrointestinal and renal toxicity. The therapeutic effects of these agents are mediated primarily through inhibition of cyclooxygenase (COX) and prevention of subsequent formation of prostaglandins and related inflammatory mediators. Nonspecific COX inhibition appears to be responsible for much of the toxicity of NSAIDs. Agents have been developed that can selectively inhibit the COX-2 isoform, while sparing COX-1. Celecoxib and other COX-2 inhibitors appear to be no more efficacious than conventional NSAIDs, but offer superior safety. COX-2 inhibitors should be considered for patients who are candidates for NSAID therapy but at risk for GI bleeding. Unlike disease-modifying antirheumatic drugs (DMARDs), these agents do not alter underlying disease progression. Leflunomide is a newer DMARD that reduces pyrimidine synthesis, thus decreasing rheumatoid inflammation. Leflunomide appears to be as effective as methotrexate but, unlike that drug, does not necessitate monitoring for bone marrow toxicity. Etanercept, the first biological agent with FDA-approved labeling for use in RA, has shown efficacy and minimal toxicity, except for injection-site reactions. Other biologicals that have been investigated for use in RA include infliximab and interleukin-1-receptor antagonist. COX-2 inhibitors, leflunomide, and etanercept are promising new drugs available for treating RA. Other agents are under development.

Trauma-induced alterations in macrophage function

Background: The juxtaposition of immune suppression and a hyperactive inflammatory response after injury represents a paradox in immune function. The aim of this study was to evaluate the delayed macrophage hypersecretion of inflammatory mediators in relation to functional macrophage defects. Methods: BALB/c mice were randomized to control or trauma (femur fracture plus 40% blood volume hemorrhage) groups. One and 7 days after injury, splenic macrophages were isolated and assayed for antigen presentation and the production of inflammatory mediators tumor necrosis factor-α (TNF-α), interleukin (IL)-6, prostaglandin E 2, H 20 2, and nitric oxide. Results: One day after injury, there were significantly diminished macrophage antigen presentation and decreased mean production of TNF-α, IL-6, and H 20 2. In contrast, 7 days after injury, splenic macrophages produced significantly increased mean amounts of TNF-α, IL-6, prostaglandin E 2, H 20 2, and nitric oxide, with a persistent functional defect in antigen presentation. Conclusions: This phasic response to trauma suggests a persistent state of macrophage dysregulation that may help explain the paradox of immune suppression, manifested by functional defects predisposing patients to increased infections, in the setting of inflammatory mediator hypersecretion, predisposing patients to the systemic inflammatory response syndrome/multiple organ dysfunction syndrome. (Surgery 1998;123:96-101.)

Nasal lavage biomarkers in air pollution epidemiology.

Epidemiological studies have shown associations between air pollution and respiratory health effects (reviewed in Bascom et al., 1996). Adverse health effects at current levels of exposures have been found for ozone, acid aerosols and particulate matter smaller than 10 μm (PM10). Effects of ozone include pulmonary function decrements, increased non-specific bronchial responsiveness and inflammatory responses (Graham and Koren, 1990; Jorens et al., 1992; Koren et al., 1989). Data based on health effects associated with acute exposure to urban particulate air pollution is rapidly growing by consistent data from epidemiological studies (Bascom et al., 1996). These data indicate that increases in daily mortality, hospitalisation, asthma exacerbation, respiratory symptoms and lung function decline are associated with ambient low levels of urban particulate air pollution measured as PM10 and lower. Possibly, air pollution induced inflammatory reactions and related inflammatory mediators are involved in altered lung function and may have implications for respiratory allergy. It is possible that ozone induces mild to moderate immune disorders by shifting vulnerable balances in the immune system, such as T help-1 and T help-2 subset ratios, resulting in altered resistance to respiratory tract infections or altering the expression of respiratory allergy. Epidemiological studies focused on inflammatory responses include the use of biomarkers.

Inflammatory mediators in relation to the development of multiple organ failure in patients after severe blunt trauma.

To evaluate the posttraumatic course of several inflammatory mediators or markers (complement components C3, C3a, terminal complement complex, thromboxane B2, C-reactive protein, elastase, and neopterin) in relation to the development of multiple organ failure and mortality. Prospective study of a selected patient group. Surgical intensive care units in three European trauma hospitals. Patients (n = 56) with severe blunt trauma (Injury Severity Score of > or = 33). Arterial blood samples were sequentially obtained. Nonsurvivors (n = 8) had significantly higher circulating C3a and elastase concentrations on the first postinjury day, compared with survivors (n = 48). No differences between these groups were found for terminal complement complex, thromboxane B2, C-reactive protein, and the neopterin/creatinine ratio. Five patients died before day 5. Eighteen patients developed multiple organ failure, which was diagnosed from day 5 onward, leaving 33 patients without multiple organ failure. The patients with subsequent multiple organ failure showed significantly higher mean circulating concentrations of C3a (914 +/- 190 [SEM] ng/mL), terminal complement complex (57 +/- 17 U/mL), and thromboxane B2 (275 +/- 37 pg/mL) at the first postinjury day than the patients without multiple organ failure (566 +/- 110 ng/mL, 27 +/- 2 U/mL, and 169 +/- 14 pg/mL, respectively). In patients with multiple organ failure, elastase concentrations were significantly higher on days 2, 3, 4, and 5 postinjury. Neopterin/creatinine ratios, on the other hand, were significantly higher in patients with multiple organ failure when the multiple organ failure had already become established (on days 8 and 10). In multiple trauma patients, excessive triggering of the inflammatory cascade-as expressed by complement activation and stimulation of neutrophils producing elastase--plays an important and early role in the development of multiple organ failure.

Identification of a novel granulocyte chemotactic protein (GCP-2) from human tumor cells. In vitro and in vivo comparison with natural forms of GRO, IP-10, and IL-8.

Stimulated human osteosarcoma cells (MG-63) were used as a source of granulocyte chemotactic protein (GCP). In addition to the previously isolated GCP-1/IL-8, natural forms of GRO alpha, GRO gamma, and IP-10 were purified and identified by amino acid sequence analysis. Further, a novel GCP, GCP-2, was isolated in its natural form (6 kDa) and was found to be structurally related to the other members of the IL-8 family. GRO alpha, IP-10, and GCP-2 showed heterogeneity, in that several forms of each protein were recovered. These differed in truncation at the amino terminus. Reverse phase HPLC allowed us to separate four such different forms of GCP-2. These tumor-derived factors were compared in granulocyte activation and chemotaxis assays. IL-8 induced neutrophil gelatinase B release at 2 nM, but GRO alpha and GCP-2 showed a 5- to 10-fold lower specific activity. When the migration of granulocytes through polycarbonate micropore membranes was measured, GCP-2 and GRO alpha had a maximal chemotactic index comparable to that of IL-8. The minimal effective dose for GCP-2 and GRO alpha was 3 to 10 nM, whereas the specific activity of IL-8 was at least 10-fold higher. IP-10 was not active in this assay at doses up to 100 nM. Finally, in vivo chemotaxis was measured by using granulocyte recruitment in the rabbit skin model. After intradermal injection of 200 ng/site, GCP-2 provoked a significant granulocyte infiltration, albeit to a lesser extent than did IL-8 and GRO alpha. GCP-2 did not attract monocytes in vivo nor did it induce the cells in vitro to migrate or to produce enzyme. In conclusion, this study reveals a new member of the IL-8 family and shows that these related inflammatory mediators possess different potencies and efficacies towards granulocytes.

Human neutrophil-specific granule deficiency: a model to assess the role of neutrophil-specific granules in the evolution of the inflammatory response

It has been suggested that neutrophil (PMN) specific granules are important in cell aggregation, locomotion, hydroxyl radical formation, and in extracellular functions such as the generation of complement- related inflammatory mediators (C5a) and the feedback regulation of myelopoiesis. In the current studies, a 9-yr-old boy with a history of recurrent infections and specific granule deficiency (absent lactoferrin, B-12 binding proteins, and characteristic specific granules on sucrose gradient centrifugation of cell homogenates) was studied to assess some of these concepts. In vivo, the patient had decreased PMN and monocyte accumulation into Rebuck skin windows but an expected febrile episode with an associated neutropenia (PMN margination) and neutrophilia (mobilization of marrow reserves) in response to intravenous endotoxin. In vitro, the patient's resting PMN showed increased ruffling, increased surface-to-volume ratio, and increased numbers of centriole-associated microtubules. His PMN showed a significant decrease in cell negative surface charge (which may relate to aggregation) in response to several stimuli and adhered better than normally to plastic. In addition, his PMN aggregated normally in response to the chemoattractant f-met-leu-phe, although the subsequent disaggregation normally seen with PMN did not occur with the patients cells. Chemotaxis of the patient's PMN to several stimuli was abnormal, and specific saturable and displaceable binding of the chemoattractant f-met-leu-[3H]phe was decreased. Similarly, following incubation with secretagogues, there was a less than normal increase in f-met-leu-[3H]phe binding and an absence of the normal increases in PMN surface area. The patient's PMN bactericidal activity, stimulated oxygen metabolism (cytochrome-c reduction, chemiluminescence, and NBT reduction), and elicited changes in membrane potential were also abnormal. Studies assessing the mechanism for the abnormal monocyte accumulation into skin windows indicated the patient's monocyte chemotaxis was better than normal in vitro. However, the patient's PMN homogenates lacked a stimulus of monocyte locomotion and did not generate chemotactic activity normally from serum. Thus, the data indicate that specific granule constituents are not required for neutrophil margination in vivo or aggregation in vitro. However, the data support the concept that PMN-specific granules are important for PMN locomotion and oxidative metabolism. In addition, extracellular release of specific granule constituents appears to be important for amplification of the initial and subsequent phases of the inflammatory response.