Update on the pathogenesis of complex regional pain syndrome: role of oxidative stress.

PURPOSE: Complex regional pain syndrome (CRPS) is a chronic inflammatory pain syndrome that affects one or more extremities of the body. It is characterized by burning pain and abnormalities in the sensory, motor, and autonomic nervous systems. This review illustrates how oxidative stress and nuclear factor erythroid 2-related factor (Nrf2) activation might contribute to understanding the etiopathogenesis of CRPS. PRINCIPAL FINDINGS: The precise cause of CRPS remains unclear, and current treatments are not effective in many patients. The mechanism underlying CRPS may differ across patients and even within a single patient over time. Inflammatory and neuronal mechanisms have been suggested as key contributors to CRPS. Recent evidence demonstrates that oxidative stress is associated with clinical symptoms in patients with CRPS-I. Oxidative stress plays a key role in CRPS pathogenesis. The Nrf2 factor is a master regulator of the transcription of multiple antioxidants, which protects against oxidative stress and inflammation by inducing antioxidant and detoxifying genes through binding with an antioxidant response element. It has antinociceptive effects against inflammatory pain in an animal model. CONCLUSION: This review summarises the effect of oxidative stress and mitochondrial dysfunction in the pathogenesis of CRPS. It also addresses the question of whether there is a potential role for Nrf2 (activated by pharmacological or nutritional activators) in alleviating the clinical features of CRPS or preventing its progression.

Antioxidative properties of paraoxonase 2 in intestinal epithelial cells.

Paraoxonase (PON) family members seem central to a wide variety of human illnesses, but appreciation of their antioxidative function in the gastrointestinal tract is in its infancy. The major objective of the present work is to highlight the role of the ubiquitously expressed PON2 in the small intestine. With use of pLKO lentiviral vector containing short hairpin RNA (shRNA) lentivirus, PON2 expression was knocked down in intestinal Caco-2/15 cells, where antioxidative status, lipid peroxidation, and degree of inflammation were evaluated. As a consequence of PON2 inactivation in the epithelial cells, we observed 1) imbalanced primary and secondary antioxidative responses, characterized by increased superoxide dismutases and decreased catalase, 2) high concentrations of H(2)O(2) and malondialdehyde, along with low glutathione-to-glutathione disulfide ratio, 3) upregulation of TNF-α, IL-6, and monocyte chemoattractant protein-1 gene expression after induction of oxidative stress, and 4) raised level of the activation of transcription factor NF-κB, which was likely implicated in exacerbation of the inflammatory activation. These results suggest that PON2 is involved in the antioxidative and anti-inflammatory response in intestinal epithelial cells.

Oxidative stress and mitochondrial functions in the intestinal Caco-2/15 cell line.

BACKGROUND: Although mitochondrial dysfunction and oxidative stress are central mechanisms in various pathological conditions, they have not been extensively studied in the gastrointestinal tract, which is known to be constantly exposed to luminal oxidants from ingested foods. Key among these is the simultaneous consumption of iron salts and ascorbic acid, which can cause oxidative damage to biomolecules. METHODOLOGY/PRINCIPAL FINDINGS: The objective of the present work was to evaluate how iron-ascorbate (FE/ASC)-mediated lipid peroxidation affects mitochondrion functioning in Caco-2/15 cells. Our results show that treatment of Caco-2/15 cells with FE/ASC (0.2 mM/2 mM) (1) increased malondialdehyde levels assessed by HPLC; (2) reduced ATP production noted by luminescence assay; (3) provoked dysregulation of mitochondrial calcium homeostasis as evidenced by confocal fluorescence microscopy; (4) upregulated the protein expression of cytochrome C and apoptotic inducing factor, indicating exaggerated apoptosis; (5) affected mitochondrial respiratory chain complexes I, II, III and IV; (6) elicited mtDNA lesions as illustrated by the raised levels of 8-OHdG; (7) lowered DNA glycosylase, one of the first lines of defense against 8-OHdG mutagenicity; and (8) altered the gene expression and protein mass of mitochondrial transcription factors (mtTFA, mtTFB1, mtTFB2) without any effects on RNA Polymerase. The presence of the powerful antioxidant BHT (50 microM) prevented the occurrence of oxidative stress and most of the mitochondrial abnormalities. CONCLUSIONS/SIGNIFICANCE: Collectively, our findings indicate that acute exposure of Caco-2/15 cells to FE/ASC-catalyzed peroxidation produces harmful effects on mitochondrial functions and DNA integrity, which are abrogated by the powerful exogenous BHT antioxidant. Functional derangements of mitochondria may have implications in oxidative stress-related disorders such as inflammatory bowel diseases.

The effects of surgery and anesthesia on memory and cognition.

This chapter describes current findings from the research into postoperative cognitive dysfunction (POCD) following cardiac and non-cardiac surgery in older adults. The evidence suggests that a significant proportion of patients show POCD in the early weeks following surgery and anesthesia. Specific domains of cognition are affected, especially memory. Much less evidence supports the presence of POCD several months or years after surgery, suggesting that POCD may be transient. However, several methodological issues make it difficult to compare findings across studies. Increasing age is among the most consistently reported patient-related risk factor. Other factors more directly related to the surgery and anesthesia are likely to contribute to the pathogenesis of POCD, including inflammatory processes triggered by the surgical procedure. Animal studies have provided valuable findings otherwise not possible in human studies; these include a correlation between the inflammatory response in the hippocampus and the development of POCD in rodents.

Interferon-gamma-dependent inhibition of late allergic airway responses and eosinophilia by CD8+ gammadelta T cells.

We have previously shown that CD8(+)gammadelta T cells decrease late allergic airway responses, airway eosinophilia, T helper 2 cytokine expression and increase interferon-gamma (IFN-gamma) expression. We hypothesized that the effects of CD8(+)gammadelta T cells were IFN-gamma mediated. Brown Norway rats were sensitized to ovalbumin on day 1. Cervical lymph node CD8(+)gammadelta T cells from sensitized animals were treated with antisense oligodeoxynucleotide (5 micromol/l) to inhibit IFN-gamma synthesis or control oligodeoxynucleotide and 3.5 x 10(4) CD8(+)gammadelta T cells were injected intraperitoneally into sensitized recipients on day 13. Rats were challenged with aerosolized ovalbumin on day 15 and lung resistance was monitored over an 8 hr period, after which bronchoalveolar lavage was performed. Control oligodeoxynucleotide treated gammadelta T cells decreased late airway responses and eosinophilia in bronchoalveolar lavage. There was a complete recovery of late airway responses and a partial recovery of airway eosinophilia in recipients of antisense oligodeoxynucleotide treated cells. Macrophage ingestion of eosinophils was frequent in rats administered gammadeltaT cells but reduced in recipients of antisense oligodeoxynucleotide treated cells. These results indicate that CD8(+)gammadelta T cells inhibit late airway responses and airway eosinophilia through the secretion of IFN-gamma. Defective or altered gammadelta T-cell function may account for some forms of allergic asthma.

Increased alveolar and plasma gelatinases activity during postpump syndrome: Inhibition by inhaled nitric oxide.

Postpump syndrome is associated with systemic inflammation. Matrix metalloproteinases (MMP)-2 and -9 contribute to proinflammatory and platelet-activator reactions. Nitric oxide (NO) is involved in the regulation of MMPs. The objectives of our study were to investigate the intensity of inflammation induced by 3 different surgical procedures, the effects of inflammation on the activity of MMPs, and the regulation of inflammation by inhaled NO (20 ppm). Inhaled NO was initiated immediately after tracheal intubation and maintained for the total duration of the experiments. Thirty pigs were equally randomized into 6 groups [sham; sham + NO; cardiopulmonary bypass; bypass + NO; bypass + lipopolysaccharide (1 microg/kg for 50 min); bypass + lipopolysaccharide + NO] and animals were subjected to anesthesia and mechanical ventilation up to 24 h. The levels of MMP-2 and MMP-9 in plasma and bronchoalveolar lavage were measured using zymography. Bypass resulted in a time-dependent rise in MMP activity, an effect potentiated by lipopolysaccharide. Inhaled NO attenuated the effects of bypass + lipopolysaccharide. These results confirm that MMP-2 and MMP-9 are associated with the inflammatory process causing the postpump syndrome. Preemptive and continuous administration of inhaled NO helps to prevent increased MMP-2 and MMP-9 activity.

Effects of hydrofluoroalkane and dry powder-formulated corticosteroids on sputum inflammatory markers in asthmatic patients.

BACKGROUND: Inhaled corticosteroids are powerful drugs that can suppress airway inflammation in asthmatic patients. Deposition of most of the inhaled corticosteroid occurs mainly in the central airways. However, a new hydrofluoroalkane formulation of beclomethasone dipropionate (HFA-BDP) is preferentially deposited in the distal airways. Inflammatory characteristics of induced sputum have been shown to differ in samples collected early after sputum induction compared with later. OBJECTIVE: To compare the effects of HFA-BDP and budesonide in a dry powder inhaler (DPI-BUD) on inflammatory cells and inflammatory cytokine expression in early and late induced sputa compared with placebo. METHODS: Seventeen patients with mild, intermittent bronchial asthma were randomly assigned to two treatment groups: eight patients received HFA-BDP and nine patients received DPI-BUD. Each patient was treated with one of the active treatments and placebo (for four weeks), with a two-week washout interval in between. Inflammatory cells and expression of interleukin (IL)-4 and IL-5 were measured in early and late induced sputa before and after active treatment, as well as before and after placebo treatment using immunocytochemistry and in situ hybridization. RESULTS: Compared with placebo, eosinophils were significantly reduced in both early and late induced sputa after HFA-BDP treatment (P<0.05), whereas DPI-BUD had a significant effect only on early induced sputum. Both HFA-BDP and DPI-BUD decreased IL-4 expression in early and late induced sputa, but the effect was more prominent with HFA-BDP. IL-5 expression was reduced in both early and late induced sputa after HFA-BDP treatment. DPI-BUD significantly decreased IL-5 expression in early but not in late induced sputum. The number of lymphocytes was not altered by either treatment. CONCLUSIONS: HFA-BDP reduced eosinophilic inflammation and T helper 2-type cytokine expression in both early and late induced sputa, whereas the effect of DPI-BUD on inflammation was predominantly demonstrated in early induced sputum.

Pre-emptive and continuous inhaled NO counteracts the cardiopulmonary consequences of extracorporeal circulation in a pig model.

Cardiopulmonary bypass (CPB) activates a systemic inflammatory response characterized clinically by alterations in cardiovascular and pulmonary function. The aim of this study was to measure the cardiopulmonary consequences in sham-operated pigs, and in animals subjected to CPB in the presence or absence of lipopolysaccharide (LPS). We also investigated, if the perioperative administration of inhaled NO exerts significant cardiopulmonary effects in an anaesthetized and mechanically ventilated pig model of extracorporeal circulation. Thirty pigs were randomized into six equal groups (sham; sham+INO; CPB; CPB+INO; CPB+LPS; CPB+LPS+INO) and subjected to anaesthesia with mechanical ventilation for up to 24h. We found that CPB+LPS group has the highest degree of lung injury. We also demonstrated that there was a significant difference on the cardiovascular parameters (heart rate, central venous pressure, stroke volume index, and mean systemic arterial blood pressure) between the CPB groups and the sham groups. The deteriorated lung mechanics was associated with a decrease in active subfraction of surfactant (LA) with time during the procedure (P=0.0003), on which inhaled NO had only an initial beneficial effect. In our model, inhaled NO had no long-term beneficial effect on lung mechanics and surfactant homeostasis despite improving lung haemodynamics, inflammation, and oxygenation. We conclude from this study that the use of pre-emptive and continuous inhaled NO therapy has protective and safe effects against lung ischemia/reperfusion associated with CPB.

Postoperative cognitive dysfunction after cardiac surgery.

Prolonged postoperative cognitive dysfunction (POCD) is reported to occur frequently after cardiac surgery. However, it is rarely assessed in routine clinical practice and receives little attention. Although the cerebral consequences of cardiopulmonary bypass have been measured clinically, insights into the resulting molecular and pathologic events within the brain have only begun to be investigated. POCD is likely to impair quality of life and constitutes a large burden on society when elderly patients prematurely lose their independence. Numerous studies have reported that neurocognitive deficit is associated with heightened mortality, increased length of hospital stay, and discharge to a nursing home. This is linked with a tremendous demand for health-care resources. Because of the magnitude of the clinical problem, serious consideration must be directed toward understanding its etiology and the development of neuroprotective strategies. Clearly identifying the mechanisms of POCD is challenging. The purpose of this review is to discuss recent developments in our understanding of the pathophysiologic mechanisms, prevention, and treatments that have been designed to ameliorate brain dysfunction after cardiac surgery.

Effects of inhaled nitric oxide on inflammation and apoptosis after cardiopulmonary bypass.

BACKGROUND: Cardiopulmonary bypass (CPB), a procedure often used during cardiac surgery, is associated with an inflammatory process that leads to lung injury. We hypothesized that inhaled nitric oxide (INO), which has anti-inflammatory properties, possesses the ability to modulate lung cell apoptosis and prevent CPB-induced inflammation. METHODS: Twenty male pigs were randomly classified into four groups: sham, sham plus INO, CPB, and CPB plus INO. INO (20 ppm) was administered for 24 h after anesthesia. CPB was performed 90 min into INO treatment. BAL fluid and blood were collected at time 0 (before CPB), at 4 h after beginning CPB, and 24 h after beginning CPB (T24). RESULTS: At T(24), BAL interleukin (IL)-8 levels and neutrophil percentages were elevated significantly in the CPB group. At T(24), INO reduced IL-8 concentrations and attenuated the increase of neutrophil percentage in the CPB-plus-INO group. Nitrite-plus-nitrate (NOx) concentrations were decreased significantly in groups without INO. Moreover, animals treated with INO showed higher rates of pulmonary apoptosis compared to their respective control groups except for the sham-plus-INO group, in which they were diminished. CONCLUSION: These results demonstrate that NOx production is reduced after CPB, and that INO acts as an anti-inflammatory agent by decreasing neutrophil numbers and their major chemoattractant, IL-8. INO also increases cell apoptosis in the lungs during inflammatory conditions, which may explain, in part, how it resolves pulmonary inflammation.

Resident CD8+ T cells suppress CD4+ T cell-dependent late allergic airway responses.

BACKGROUND: The role of CD8+ T cells in the immune response to airway challenge with an allergen is poorly understood. OBJECTIVE: The aim of this study was to test the hypothesis that resident naive CD8+ T cells modulate the magnitude of CD4+ T cell-dependent allergic airway responses. METHODS: Cervical lymph node CD4+ T cells (2 x 10(6)) were harvested from ovalbumin (OVA)- or sham-sensitized rats and injected intraperitoneally into naive Brown Norway recipients. The recipients were treated with a CD8alpha mAb (OX-8) to deplete the resident CD8+ T cells (n = 12) or mouse ascites (n = 12). Two days after adoptive transfer, the recipient animals were OVA challenged, lung resistance was measured for 8 hours, and bronchoalveolar lavage (BAL) was performed. RESULTS: After OVA challenge, primed CD4-transferred CD8-depleted rats had larger early airway responses and late airway responses compared with primed CD4-transferred CD8-nondepleted rats (early airway responses: 158.6% +/- 19.2% vs 115.7% +/- 5.9%, P < .05; late airway responses: 8.5% +/- 1.7% vs 4.4% +/- 0.9%, P < .05). BAL eosinophilia was also greater (4.67% +/- 0.45% vs 2.34 +/- 0.26%, P < .01). The cells in BAL fluid expressing IL-4 mRNA were not significantly changed by CD8 depletion, but IL-5 mRNA+ cells were higher in number, and IFN-gamma mRNA+ cells were fewer in the CD8-depleted group. CONCLUSIONS: Resident CD8+ T cells downregulate the late allergic response and airway inflammation evoked by CD4+ T-cell transfers in Brown Norway rats. This downregulation does not require antigen priming.

CD8+ alphabeta T cells can mediate late airway responses and airway eosinophilia in rats.

BACKGROUND: The function of CD8+ T-cell subsets in mediating late allergic responses is incompletely understood. OBJECTIVE: We sought to test the hypothesis that CD8+ alphabeta T cells are proinflammatory in the airways in vivo by using a well-characterized animal model and the technique of adoptive transfer. METHODS: Brown Norway rats were administered CD8 + alphabeta T cells (10 6 ) intraperitoneally purified from lymph node cells of either naive or ovalbumin (OVA)-sensitized rats and were challenged with aerosolized OVA 2 days later. Control rats were sensitized to 100 mug of OVA in Al(OH) 3 subcutaneously or sham sensitized to saline and were OVA challenged 2 weeks later. RESULTS: The OVA-sensitized and OVA-challenged group and the recipients of OVA-primed CD8+ alphabeta T cells had significant late airway responses calculated from lung resistance measured for an 8-hour period after challenge compared with the naive CD8 + alphabeta T cell-transferred group and the sham-sensitized control group. The number of eosinophils in bronchoalveolar lavage fluid increased in the OVA-sensitized group and the OVA-primed CD8+ alphabeta T-cell recipients compared with numbers in the naive CD8+ alphabeta T-cell recipients and the sham-sensitized control group. IL-4 and IL-5 cytokine mRNA expression in bronchoalveolar lavage fluid increased in the OVA-sensitized group and the OVA-primed CD8+ alphabeta T-cell recipients compared with that in the sham-sensitized group. CONCLUSION: We conclude that antigen-primed CD8 + alphabeta T cells might have a proinflammatory role in allergen-driven airway responses in the rat.

Similar allergic inflammation in the middle ear and the upper airway: evidence linking otitis media with effusion to the united airways concept.

BACKGROUND: Otitis media with effusion (OME) is a chronic inflammatory disease of the middle ear space characterized by the accumulation of fluid. Previous investigations have suggested that the immunopathologic mechanism underlying the development of middle ear effusion in patients with allergy is largely due to the effects of T(H)2 mediators. The composition of the inflammatory substrate in the effusions of allergic otitis media is similar to the late-phase allergic response seen elsewhere in the respiratory tract, such as in asthma and in allergic rhinitis. OBJECTIVE: To determine whether the middle ear compartment may be a component of the united airways in allergic disease by comparing the inflammatory profiles of the middle ear to the upper airway. METHODS: Middle ear effusions, torus tubaris (Eustachian tube mucosa at the nasopharyngeal orifice), and adenoidal tissue biopsies were obtained from 45 patients undergoing simultaneous tympanostomy tube placement for OME and adenoidectomy for adenoid hypertrophy. The cellular and cytokine profiles of each site were investigated by using immunocytochemistry (elastase, CD3, major basic protein) and in situ hybridization (IL-4, IL-5, IFN-gamma mRNA). Atopic status was determined for each patient by using skin prick testing. RESULTS: Eleven of the 45 patients with OME (24%) were atopic. The middle ear effusions of atopic patients had significantly higher levels of eosinophils, T lymphocytes, and IL-4 mRNA + cells ( P < .01) and significantly lower levels of neutrophils and IFN-gamma mRNA + cells ( P < .01) compared with nonatopic patients. The nasopharyngeal tissue biopsies revealed similar cellular and cytokine profiles. CONCLUSION: In atopic patients with OME, the allergic inflammation occurs on both sides of the Eustachian tube, both in the middle ear and in the nasopharynx. The results of this study support the concept that the middle ear may be part of the united airway in atopic individuals.

Fractional analysis of Th2-type cytokines in sequential samples of induced sputum.

BACKGROUND: Recent studies have demonstrated the usefulness of induced sputum in detecting the expression of Th2-type cytokines in asthmatics and have shown that the profile of inflammatory cells in induced sputum differs with time. OBJECTIVE: To determine whether the duration of sputum induction also affects the expression of Th2-type cytokines in induced sputum. METHODS: Induced sputum was collected from eight atopic asthmatics at two separated intervals (5 min each) during a 15 min sputum induction, and each sample was examined separately for cytokine expression and inflammatory cells. Using immunocytochemistry, interleukin (IL)-4 and IL-5 immunoreactivity, T lymphocytes (CD3), eosinophils (major basic protein), neutrophils (elastase), epithelial cells and macrophages (CD68) were compared in the induced sputum obtained from the 0 min to 5 min and the 10 min to 15 min samples. RESULTS: The number of immunoreactive-positive cells expressing IL-4 and IL-5 were significantly higher in the 10 to 15 min induced sputum sample than in the 0 min to 5 min induced sputum sample (P<0.05). The number of eosinophils was also significantly higher in the 10 min to 15 min sample than in the 0 min to 5 min sample (P<0.05). In contrast, the number of neutrophils was significantly higher in the 0 min to 5 min sample than in the 10 min to 15 min sample (P<0.01); T lymphocytes, macrophages and epithelial cells did not differ between the two samples. CONCLUSION: This study demonstrates that the duration of sputum induction significantly affects the profile of inflammatory cells and Th2-type cytokine expression, and underscores the need for the standardization of induced sputum procedure.

CD4+ T cells migrate from airway to bone marrow after antigen inhalation in rats.

BACKGROUND: IL-5-producing T lymphocytes increase in rat bone marrow after inhalational challenge with allergen. OBJECTIVE: To test the hypothesis that T cells migrate from the airways to the marrow, we examined the trafficking of T cells in Brown Norway rats after sensitization and challenge with ovalbumin. METHODS: Purified CD4+ T cells, harvested from cervical lymph nodes of naive and ovalbumin-sensitized donors, were labeled with carboxy fluorescein diacetate succinimidyl ester; 20 x 10(6) cells were placed in the trachea of naive or sensitized recipients under anesthesia, and 18 hours later, animals were challenged with inhaled ovalbumin. Cells were harvested 24 hours later from the bone marrow, bronchoalveolar lavage fluid, lungs, the lung blood pool of cells, lung draining lymph nodes, peripheral blood, and spleen. RESULTS: The number of carboxy fluorescein diacetate succinimidyl ester-positive cells, measured by fluorescence-activated cell sorter, in the bone marrow of ovalbumin sensitized, primed T-cell recipients was higher than either the sham-sensitized, primed T-cell recipients or sham-sensitized, naive T-cell recipients (P < .05). The number of eosinophils in both bone marrow and bronchoalveolar lavage fluid was increased in ovalbumin-sensitized, primed T-cell recipients. The expression of the T-cell chemoattractants eotaxin and IL-16, evaluated by immunohistochemistry, was higher in the bone marrow of ovalbumin-sensitized, primed T-cell recipients. CONCLUSIONS: CD4+ T cells travel from airway to bone marrow after antigen inhalation. The homing of the CD4+ T cells might be facilitated by eotaxin and IL-16 expression in the bone marrow and might contribute to the stimulation of eosinophilopoiesis after airway allergen exposure.

Evidence of allergic inflammation in the middle ear and nasopharynx in atopic children with otitis media with effusion.

BACKGROUND: Otitis media with effusion (OME) occurs in the setting of eustachian tube (ET) dysfunction. Previous studies have demonstrated a predominance of T helper 2 (Th2) mediators in the middle ear effusions (MEEs) of atopic children, suggesting that allergy plays a role in the pathogenesis of OME. Given that the middle ear is contiguous with the upper airway, the allergic inflammation seen in the middle ear of atopic patients with OME may also have been observed in the nasopharynx. OBJECTIVE: We hypothesize that atopic children have different cellular and cytokine profiles in MEE compared with nonatopic patients and that this allergic inflammation occurs in both the middle ear and the nasopharynx. METHODS: Forty-five patients undergoing both ventilation tube placement for OME and adenoidectomy for adenoid hypertrophy were recruited. The atopic status was determined for each patient using standard skin testing. The cellular and cytokine profiles of the MEEs and the torus tubarius and adenoid tissues were investigated using immunocytochemistry and in situ hybridization. RESULTS: Our results indicate that, within the atopic patient, there is a similar cellular and cytokine profile within the three regions sampled, with a predominant expression of interleukin-4 (a Th2 cytokine) and an increased infiltration of eosinophils compared with the nonatopic patient. CONCLUSION: These findings confirm the association of allergy with MEE and support the hypothesis that the middle ear may be an integral part of the United Airway Concept.

5-oxo-6,8,11,14-eicosatetraenoic acid induces the infiltration of granulocytes into human skin.

BACKGROUND: 5-Oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE) is an arachidonic acid metabolite with potent in vitro chemoattractant effects on eosinophils and neutrophils. It has also been shown to induce pulmonary eosinophilia in Brown Norway rats, but it is not known whether it is active in human beings in vivo. OBJECTIVE: To determine whether 5-oxo-ETE can induce cellular infiltration in patients with atopic asthma and nonatopic control subjects after intradermal administration. METHODS: 5-Oxo-ETE was administered intradermally to 11 patients with atopic asthma and 10 nonatopic control subjects. Skin biopsy specimens were taken 6 or 24 hours later and examined by immunocytochemistry for cells expressing specific markers for eosinophils (major basic protein), neutrophils (elastase), macrophages (CD68), lymphocytes (CD3), and mast cells (tryptase). RESULTS: 5-Oxo-ETE (1.5 and 5 microg) elicited the infiltration of both eosinophils and neutrophils into the skin in both control and atopic asthmatic subjects. Increased numbers of eosinophils were observed at 6 and 24 hours after injection, whereas significantly elevated neutrophil numbers were present only after 24 hours. Eosinophils were >3 times higher in patients with atopic asthma compared with control subjects after injection of the highest dose of 5-oxo-ETE. Macrophage numbers were also elevated, but only at the highest dose of 5-oxo-ETE. No effects were observed on the numbers of either lymphocytes or mast cells. CONCLUSIONS: 5-Oxo-ETE elicits the infiltration of eosinophils and neutrophils into the skin of human beings in vivo after intradermal administration. Asthmatic subjects are more responsive to this substance than nonallergic control subjects. These results suggest that 5-oxo-ETE may be an important mediator of inflammation.

The effects of CD8+gammadelta T cells on late allergic airway responses and airway inflammation in rats.

BACKGROUND: Gamma-delta (gammadelta) T cells regulate immune responses to foreign protein at mucosal surfaces. Whether they can modify allergen-induced early (EAR) and late airway responses (LAR) is unknown. OBJECTIVE: We have tested the hypothesis that the CD8+ subtype of gammadelta T cells decreases allergen-induced LAR and airway eosinophilia in the rat. METHODS: Brown Norway rats were administered, intraperitoneally, 3.5 x 10(4) lymph node CD8+gammadelta T cells from naive or sensitized rats. The recipients were sensitized to ovalbumin (OVA) in Al(OH)(3) 3 days after cell transfer and challenged with aerosolized OVA 14 days later. Serum IgE was measured before allergen challenge. After challenge, lung resistance was monitored for 8 hours and then bronchoalveolar lavage (BAL) was analyzed for eosinophil major basic protein (MBP), IL-4, IL-5, IL-13, and IFN-gamma messenger RNA-expressing cells. RESULTS: gammadelta T cells from naive donors significantly decreased LAR in OVA-challenged sensitized rats, whereas MBP(+) eosinophils were decreased by both gammadelta T cells from naive and sensitized donors. EAR and serum IgE levels were unchanged. The expression of IL-4, IL-5, and IL-13 by BAL cells of gammadelta T cell recipients was attenuated compared with OVA-challenged controls. This was accompanied by an increase in the expression of IFN-gamma. CONCLUSIONS: Our results are consistent with a suppressive role of CD8+gammadelta T cells on allergic airway responses. However, only gammadelta T cells from naive donors inhibit LAR.

T helper type 2 cytokine receptors and associated transcription factors GATA-3, c-MAF, and signal transducer and activator of transcription factor-6 in induced sputum of atopic asthmatic patients.

BACKGROUND: It is well-known that the expression of T helper (Th) type 2 cytokines such as interleukin (IL)-4 and IL-5, and their receptors, is up-regulated within the airways of allergic asthmatic patients. Furthermore, higher numbers of cells producing GATA-3, c-MAF, and signal transducer and activator of transcription factor (STAT)-6, which are transcription factors (TFs) that are implicated in the regulation and signaling of the Th2 cytokines, have been observed in bronchial biopsy specimens from asthmatic patients but not in those of healthy control subjects. METHODS: We examined whether these mediators also can be detected in induced sputum. Immunoreactivity for IL-4Ralpha, IL-5Ralpha, GATA-3, c-MAF, and STAT-6 was investigated in samples of induced sputum from asthmatic patients (n = 8) and healthy control subjects (n = 8). RESULTS: Our results showed that the numbers of cells expressing IL-4 receptor alpha (Ralpha) and IL-5Ralpha were higher in samples from asthmatic patients compared to those of control subjects (p < 0.01). More cells exhibiting GATA-3, c-MAF, and STAT-6 immunoreactivity also were found in asthmatic patients vs those in control subjects (p < 0.005). Furthermore, the expression of STAT-6 and IL-4Ralpha, GATA-3 and IL-5Ralpha, and c-MAF with both IL-4Ralpha and IL-5Ralpha was correlated (p < 0.05). CONCLUSIONS: This study demonstrated that induced sputum provides sufficient sensitivity for examining the pathways of cytokine signaling, cytokine receptor signaling, and intracellular signaling. Furthermore, these data show correlations between the expression of Th2 cytokine receptors and associated TFs in the human lung, which has not been documented previously.