Supercritical fluid extraction of plutonium and americium from soil using thenoyltrifluoroacetone and tributylphosphate complexation

Samples of clean soil from the source used to backfill pits at the Idaho National Engineering and Environmental Laboratory´s Radioactive Waste Management Complex were spiked with239Pu and241Am to evaluate ligand-assisted supercritical fluid extraction as a decontamination method. The actual soil in the pits has been subject to approximately three decades of weathering since it was originally contaminated. No surrogate soil can perfectly simulate the real event, but actual contaminated soil was not available for research purposes. However, fractionation of Am and Pu in the surrogate soil was found to be similar to that previously measured in the real soil using a sequential aqueous extraction procedure. This suggests that Pu and Am behavior are similar in the two soils. The surrogate was subjected to supercritical carbon dioxide extraction, in the presence of the fluorinated beta diketone thenoyltrifluoroacetone (TTA), and tributylphosphate (TBP). As much as 69% of the Pu and 88% of the Am were removed from the soil using 3.2 mol.% TTA and 2.7 mol.% TBP, in a single 45 minute extraction. Extraction conditions employing a 5 mol.% ethanol modifier with 0.33 mol.% TTA and 0.27 mol.% TBP resulted in 66% Pu and 68% Am extracted. To our knowledge, this is the first report of the use of supercritical fluid extraction (SFE) for the removal of actinides from soil.

Role of GPIIb-IIIa in platelet-monocyte and platelet-neutrophil conjugate formation in whole blood

Platelets in stirred whole blood can be induced to form aggregates and also to form heterotypic platelet-monocyte (P/M) and platelet-neutrophil (P/N) conjugates. Here we have investigated the effects of three GPIIb-IIIa antagonists (GR144053F, MK-852 and Reopro, a CD62P-blocking antibody, GA6, and EDTA on the conjugate formation that occurs on stirring whole blood and in response to adding ADP and PAF. We have confirmed the identities of the conjugates by light microscopy after cell sorting. Platelet aggregation was measured by platelet counting. Monocytes, neutrophils, P/M and P/N were detected and quantitated using immunofluorescence and flow cytometry. Stirring whole blood resulted in both platelet aggregation and formation of P/M but not P/N. Adding ADP or PAF to whole blood caused rapid platelet aggregation and generation of both P/M and P/N. All of the GPIIb-IIIa antagonists studied had similar effects: inhibition of stirring-induced platelet aggregation and P/M formation, and inhibition of ADP-induced platelet aggregation and P/N formation. In contrast, they accelerated ADP induced-P/M conjugate formation and PAF-induced formation of both P/M and P/N. Both EDTA and GA6 completely inhibited P/M and P/N, which is commensurate with CD62P being involved in platelet-leucocyte conjugate formation. The results of these investigations suggest that GPIIb-IIIa has a dual role in determining the interaction between platelets and leukocytes.

Tetracyclines and pulmonary inflammation

Tetracycline and its derivatives, such as chlortetracycline, oxytetracycline, minocycline, doxycycline, methacycline and lymecycline, are naturally occurring or semi-synthetic polyketide compounds that exhibit a well known broad-spectrum antibacterial activity that interferes with prokaryotic protein synthesis at the ribosome level. In addition to this well known antibacterial activity these compounds also exhibit a variety of additional, less well known properties. Among them are separate and distinct anti-inflammatory properties. Tetracycline and related compounds have been shown to be effective chemotherapeutic agents in a wide variety of chronic inflammatory diseases and conditions. These include periodontitis, rosacea, acne, auto-immune diseases such as rheumatoid arthritis and protection of the central nervous system against trauma and neurodegenerative diseases such as stroke, multiple sclerosis and Parkinson disease. Tetracycline and related compounds appear to be beneficial for treatment of several chronic inflammatory airway diseases. Among them are asthma, bronchiectasis, acute respiratory distress syndrome, chemical induced lung damage and cystic fibrosis. The clinical use of tetracycline-type drugs in treatment of chronic airway inflammation is becoming a topic of intense interest. Recent findings in this area have led to an understanding of the myriad physiological, cellular and molecular mechanisms of the inflammatory response and how this response may be controlled to limit damage to host cells and tissues. This review presents a brief summary of the recent research in the area of tetracycline and its derivatives in control of pulmonary inflammation.

Macrolide antibiotics and pulmonary inflammation

Many clinically effective therapeutic agents can exhibit localized and systemic effects that are manifestly different from their intended primary pharmacological mode of action. Macrolide antibiotics such as erythromycin and its derivatives are no exception. In addition to their antibacterial action, this class of antibiotics exhibits anti-inflammatory activity in a variety of airway diseases such as asthma and diffuse panbronchiolitis that is separate and distinct from a direct antibacterial action. A variety of erythromycin derivatives have been shown to be clinically beneficial in these airway diseases. The anti-inflammatory activities of these macrolide antibiotics are becoming a research topic of intense interest. Recent work in this field has led to the understanding of the various physiological, cellular and molecular processes of the inflammatory response that are inhibited or suppressed by these compounds. This review presents a brief summary of the fascinating recent work in this active research area.

Temporal stability of the Minnesota Multiphasic Personality Inventory (MMPI) in patients undergoing lumbar fusion: a poor predictor of surgical outcome

In this prospective study, the Minnesota Multiphasic Personality Inventory (MMPI) was administered to patients before and after lumbar spines fusion to investigate the stability of MMPI scores after surgical intervention and to attempt to correlate MMPI scale scores with outcome data. Sixty-eight patients were included. Testing was performed before surgery and at a mean of 1.5 years after surgery. Clinical outcome ratings were assigned by using criteria of pain relief and analgesic use. In addition, demographic variables known to affect outcome were analyzed. Sixty percent of the patients had a successful clinical outcome. Positive outcome correlated with the demographic factors of occupation (homemaker) and solid fusion. MMPI scales were stable across time, with no difference between groups. Independent t tests were used to study preoperative MMPI scores with respect to clinical outcome. Unsatisfactory outcomes were associated with higher scores on scales 1, 3, and 10 before surgery. Postoperative testing revealed significant outcome correlations--higher scores on scales 1, 2, 3, 5, 7, and 8 associated with an unsatisfactory outcome. However, discriminant function analysis of preoperative MMPI data was able to classify outcomes correctly in only 58.8% of the cases. The utility of the MMPI as a predictor of outcome after surgical intervention is quite limited. Use of group data and testing before and after surgery does not appear to influence this conclusion. Although the scores as a group were stable across time, the amount of variance in outcome that could not be accounted for by using MMPI scales as predictors was unacceptably large.

Peroxynitrite inhibits inducible (type 2) nitric oxide synthase in murine lung epithelial cells in vitro

Peroxynitrite, formed by nitric oxide (NO) and superoxide, can alter protein function by nitrating amino acids such as tyrosine, cysteine, trytophan, or methionine. Inducible nitric oxide synthase (Type 2 NOS or iNOS) converts arginine to citrulline, releasing NO. We hypothesized that peroxynitrite could function as a negative feedback modulator of NO production by nitration of iNOS. Confluent cultures of the murine lung epithelial cell line, LA-4 were stimulated with cytokines to express iNOS, peroxynitrite was added, and the flasks sealed. After 3 h, NO in the headspace above the culture was sampled. Peroxynitrite caused a concentration-dependent decrease in NO. Similar results were obtained when 3-morpholinosydnonimine (SIN-1), a peroxynitrite generator, was added to the flasks. PAPA-NONOate, the NO generator, did not affect the headspace NO. Nitration of the iNOS was confirmed by detection of 3-nitrotyrosine by Western blotting. These data suggest a mechanism for inhibition of NO synthesis at inflammatory sites where iNOS, NO, and superoxide would be expected.

Methotrexate stimulates lung fibroblasts and epithelial cells to release eosinophil chemotactic activity

OBJECTIVE

To determine if methotrexate (MTX) induces human lung fibroblast (HFL-1) and epithelial (BEAS 2B) cell lines to release eosinophil chemotactic activity (ECA).

METHODS

HFL-1 and BEAS 2B cell supernatant fluids were evaluated for ECA by a blind well chamber technique.

RESULTS

HFL-1 and BEAS-2B cells released ECA in a dose and time dependent manner in response to MTX. Partial characterization revealed that ECA was partly heat labile, trypsin sensitive, and ethylacetate extractable. Thus the culture supernatant fluids were evaluated for known eosinophil chemotactic factors. Although several were released constitutively, granulocyte-macrophage colony-stimulating factor (GM-CSF) was significantly increased in response to MTX from both cell types. Consistent with these observations, ECA from both cell types was inhibited by GM-CSF antibodies.

CONCLUSION

These data suggest that lung fibroblasts and epithelial cells may modulate eosinophil recruitment into the lung by releasing ECA in response to MTX.

Inflammatory cytokines modulate eotaxin release by human lung fibroblast cell line

Eotaxin, a potent eosinophil-specific chemotactic factor, is increased in the lower respiratory tract of asthma patients. Recently, lung fibroblasts have been reported to produce eotaxin and their activation can be modulated by inflammatory cytokines. To test the hypothesis that inflammatory cytokines modulate the eotaxin release from lung fibroblasts, we investigated the potential of interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), or interferon-gamma (IFN-gamma) to induce the release of eotaxin and eotaxin mRNA by the human fetal lung fibroblast cell line, HFL-1, was evaluated. HFL-1 released eotaxin constitutively without stimulation, but IL-1beta or TNF-alpha stimulated eotaxin release in a dose- and time-dependent manner. IL-1beta or TNF-alpha treatment of HFL-1 also resulted in the augmented expression of eotaxin mRNA. Although IFN-gamma alone had negligible effect on eotaxin release and mRNA expression, IFN-gamma induced a significant, concentration-dependent attenuation of eotaxin release and eotaxin mRNA expression from HFL-1 stimulated with IL-1beta or TNF-alpha. These findings are consistent with the concept that lung fibroblast-derived eotaxin may in part be responsible for the eosinophil infiltration observed in the airways of asthmatic patients and that network of cytokines may modulate the eosinophil recruitment to the airways by stimulation of fibroblasts to release eotaxin.

Quality of life in ALS is maintained as physical function declines

OBJECTIVES

To study patients with ALS to determine how physical function, quality of life (QOL), and spirituality or religiousness change over time, and what relationship these changes have to one another.

METHODS

Sixty patients with ALS were studied prospectively. They were assessed at baseline, 3 months, and 6 months, using questionnaires designed to measure general quality of life (McGill Quality of Life questionnaire), religiosity (Idler Index of Religiosity), ALS-specific health-related quality of life (SIP/ALS-19), and ALS-specific function (ALS functional rating scale).

RESULTS

A two-way repeated measures multivariate analysis of variance revealed that both the passage of time and the specific QOL scales used were factors in predicting patient quality of life (F[1, 59]= 9.87, p < 0.003 and F[3, 177]= 16.90, p < 0.001) Despite a progressive decline in physical function as measured by the ALS-specific function score, the general QOL and religiosity scores changed little. In contrast, the ALS-specific health-related QOL score declined in parallel with the ALS-specific function score.

CONCLUSIONS

QOL in patients with ALS appears to be independent of physical function, which agrees with a previous cross-sectional study. The ALS-specific health-related QOL score is primarily a measure of physical function. QOL instruments that assess spiritual, religious, and psychological factors produce different results than those obtained using measures of physical function alone.

Erythromycin modulates eosinophil chemotactic cytokine production by human lung fibroblasts in vitro

Recent studies suggest that erythromycin can suppress the production of some cytokines and may be an effective treatment for asthma. Eosinophil chemotactic cytokines have been suggested to contribute to the pathogenesis of asthma by the recruitment of eosinophils. We hypothesized that erythromycin modulates eosinophil chemotactic cytokine production. To test the hypothesis, we evaluated the potential of erythromycin to modulate the release of eosinophil chemoattractants from the human lung fibroblast cell line HFL-1. HFL-1 released eotaxin, granulocyte-macrophage colony-stimulating factor, and regulated and normal T-cell expressed and presumably secreted (RANTES) in response to interleukin-1beta or tumor necrosis factor alpha. Erythromycin attenuated the release of these cytokines and eosinophil chemotactic activity by the HFL-1. The suppressive effect on eotaxin was the most marked of these cytokines. Erythromycin therapy also suppressed eotaxin mRNA significantly. These results suggest a mechanism that may account for the apparent beneficial action of macrolide antibiotics in the treatment of allergic airway disorders.

Reactive oxygen and nitrogen metabolites modulate fibronectin-induced fibroblast migration in vitro

Nitration of proteins by peroxynitrite may alter protein function. We hypothesized that reactive nitrogen species modulate fibronectin-induced fibroblast migration. To test this hypothesis, we evaluated fibroblast migration induced by fibronectin incubated with and without peroxynitrite. Peroxynitrite attenuated fibronectin-induced fibroblast migration in a dose-dependent manner but did not attenuate complement-activated serum-induced fibroblast migration. The reducing agents, deferoxamine and dithiothreitol (DTT), and L-tyrosine reversed the inhibition by peroxynitrite. PAPA-NONOate, a nitric oxide (NO) donor, and superoxide generated by the action of xanthine oxidase on lumazine or xanthine, also showed an inhibitory effect on fibroblast migration. The peroxynitrite generator, 3-morpholinosydnonimine (SIN-1), caused a concentration-dependent inhibition of fibroblast migration. Peroxynitrite reduced fibronectin binding to fibroblasts and resulted in nitrotyrosine formation. These findings are consistent with nitration of tyrosine by peroxynitrite with subsequent inhibition of fibronectin binding to fibroblasts and suggest that peroxynitrite may play a role in regulation of fibroblast migration.

Bleomycin stimulates lung fibroblast and epithelial cell lines to release eosinophil chemotactic activity

The presence of eosinophils in the lungs of patients with pulmonary fibrosis correlates with poor prognosis or resistance to therapy. Furthermore, eosinophils localize to areas undergoing active fibrosis. It was hypothesized that a human lung fibroblast (HFL-1) and a human lung epithelial cell line (BEAS-2B) might release eosinophil chemotactic activity (ECA) in response to bleomycin, a chemotherapeutic agent associated with pulmonary fibrosis. HFL-1 and BEAS-2B cells were cultured in the presence of bleomycin and their supernatant fluids evaluated for ECA by means of a Boyden chamber method. HFL-1 and BEAS-2B cells released ECA in a dose- and time-dependent manner in response to bleomycin, and partial characterization revealed that the ECA was heterogeneous. ECA release from HFL-1 and BEAS-2B cells was significantly reduced by a leukotriene B4 (LTB4) receptor antagonist and an antibody directed against granulocyte-macrophage colony-stimulating factor. HFL-1 cells released LTB4, eotaxin, and GM-CSF constitutively, and BEAS-2B cells released LTB4, eotaxin, regulated on activation, normal T-cell expressed and presumably secreted, and GM-CSF constitutively. In both cases, the release of GM-CSF was significantly increased in response to bleomycin. These data suggest that lung fibroblasts and epithelial cells may modulate eosinophil recruitment into the lung in bleomycin-induced pulmonary fibrosis.

Chicken soup inhibits neutrophil chemotaxis in vitro

Chicken soup has long been regarded as a remedy for symptomatic upper respiratory tract infections. As it is likely that the clinical similarity of the diverse infectious processes that can result in "colds" is due to a shared inflammatory response, an effect of chicken soup in mitigating inflammation could account for its attested benefits. To evaluate this, a traditional chicken soup was tested for its ability to inhibit neutrophil migration using the standard Boyden blindwell chemotaxis chamber assay with zymosan-activated serum and fMet-Leu-Phe as chemoattractants. Chicken soup significantly inhibited neutrophil migration and did so in a concentration-dependent manner. The activity was present in a nonparticulate component of the chicken soup. All of the vegetables present in the soup and the chicken individually had inhibitory activity, although only the chicken lacked cytotoxic activity. Interestingly, the complete soup also lacked cytotoxic activity. Commercial soups varied greatly in their inhibitory activity. The present study, therefore, suggests that chicken soup may contain a number of substances with beneficial medicinal activity. A mild anti-inflammatory effect could be one mechanism by which the soup could result in the mitigation of symptomatic upper respiratory tract infections.

Quality of life in ALS depends on factors other than strength and physical function

OBJECTIVES

To study patients with ALS to determine the following: 1) the relationship between physical function and quality of life (QOL); 2) the instruments that best reflect patients' own ratings of QOL; and 3) whether spiritual/religious factors play a role in determining QOL.

METHODS

The authors prospectively studied 96 patients with ALS using several instruments, including the McGill Quality of Life (MQOL) instrument, the Idler Index of Religiosity, the Sickness Impact Profile (SIP)/ALS-19, and several measures of strength and physical function.

RESULTS

QOL as assessed by patients (MQOL single item score) did not correlate with measures of physical function and strength, but correlated with the total MQOL score (p < 0.0005), the psychological and existential subscores of MQOL (p < 0. 0005), the support subscore of MQOL (p = 0.001), and the total Idler score (p = 0.001). In contrast, correlations between SIP/ALS-19 and these measures were not significant, although SIP/ALS-19 correlated with measures of physical function and strength.

CONCLUSIONS

QOL, as assessed by the patient with ALS, does not correlate with measures of strength and physical function, but appears to depend on psychological and existential factors, and thus may be measured well by the MQOL scale. Spiritual factors and support systems appear to play roles as well. SIP/ALS-19 is a good measure of physical function, but not of overall QOL.

Elevation of nitrotyrosine and nitrate concentrations in cystic fibrosis sputum

Nitric oxide (NO) is increased in the exhaled air of some patients with inflammatory lung disorders, but not in others. NO may combine with superoxide to form peroxynitrite, which lowers NO gas concentrations, increases formation of nitrate, and increases nitration of tyrosine residues on proteins. We hypothesized that superoxide released from neutrophils in the lower respiratory tract of cystic fibrosis (CF) results in increased nitrate and nitrotyrosine levels in sputum. In order to test this hypothesis, exhaled NO was collected from 5 stable adult CF subjects and from 5 nonsmoking normal controls. Consistent with previous reports, exhaled NO concentrations were not increased in CF exhaled air (22.6 +/- 1.5 ppb vs. 28.6 +/- 1.5 ppb in normals, P > 0.05). Sputum was collected from 9 adult CF subjects and the same 5 normal controls and evaluated for nitrite, nitrate, and nitrotyrosine. Nitrate and nitrotyrosine levels, but not nitrite, were significantly elevated in CF. Recently, myeloperoxidase has also been implicated as a mechanism of nitrotyrosine formation. Therefore, myeloperoxidase was measured and found to be elevated in the CF sputum (64.2 +/- 35.9 vs. 0.73 +/- 0.16 U/mL, P < 0.001), and was found to correlate with concentrations of nitrotyrosine (r = 0.87, P < 0.05). However, in vitro studies with myeloperoxidase and murine lung epithelial cells did not demonstrate a reduction of NO gas with nitrotyrosine or an increase in nitrate formation. These data demonstrate that nitrate and nitrotyrosine are elevated in the sputa of CF subjects and suggest increased production of NO in the lower respiratory tract of CF patients, despite the relatively low exhaled NO levels. Pediatr Pulmonol. 2000; 30:79-85. Published 2000 Wiley-Liss, Inc.

Bradykinin stimulates eotaxin production by a human lung fibroblast cell line

BACKGROUND

Bradykinin, a potent inflammatory peptide, is increased in the airways of allergic patients. Accompanying the elevated bradykinin levels are increases in both eosinophils and fibroblasts. Eotaxin, a potent eosinophil-specific chemotactic factor, is released by fibroblasts and increased in the lower respiratory tract of allergic patients.

OBJECTIVE

We sought to test the hypothesis that lung fibro-blasts release eotaxin in response to bradykinin.

METHODS

The potential of bradykinin to induce the release of eotaxin from the human lung fibroblast cell line HFL-1 was tested by cell culture and evaluation of the culture supernatant fluids and RNA for immunoreactive eotaxin and eotaxin messenger RNA.

RESULTS

HFL-1 cells released eotaxin constitutively without stimulation, but bradykinin stimulated eotaxin release in a dose- and time-dependent manner and resulted in augmented expression of eotaxin messenger RNA. The release of eotaxin was sensitive to the action of glucocorticoids. Eosinophil chemotactic activity by HFL-1 supernatant fluids was inhibited by anti-human eotaxin-neutralizing antibody. Consistent with these results, inhibitors of bradykinin B2 receptors, but not bradykinin B1 receptors, inhibited bradykinin-induced eotaxin release.

CONCLUSION

These data demonstrate that bradykinin may stimulate lung fibroblasts to release eotaxin and suggest the potential for this mechanism to be important in modulation of lung inflammation.

Reactive nitrogen and oxygen species attenuate interleukin- 8-induced neutrophil chemotactic activity in vitro

Peroxynitrite, formed by the reaction between nitric oxide and superoxide, has been shown to induce protein nitration, which compromises protein function. We hypothesized that peroxynitrite may regulate cytokine function during inflammation. To test this hypothesis, the neutrophil chemotactic activity (NCA) of interleukin-8 (IL-8) incubated with peroxynitrite was evaluated. Peroxynitrite attenuated IL-8 NCA in a dose-dependent manner (p < 0.01) but did not significantly reduce NCA induced by leukotriene B(4) or complement-activated serum. The reducing agents, dithionite, deferoxamine, and dithiothreitol, reversed and exogenous L-tyrosine abrogated the peroxynitrite-induced NCA inhibition. Papa-NONOate [N-(3-ammoniopropyl)-N-(n-propyl)amino]diazen-1-ium-1, 2-dialase or sodium nitroprusside, NO donors, or a combination of xanthine and xanthine oxidase to generate superoxide did not show an inhibitory effect on NCA induced by IL-8. In contrast, small amounts of SIN-1, a peroxynitrite generator, caused a concentration-dependent inhibition of NCA by IL-8. Consistent with its capacity to reduce NCA, peroxynitrite treatment reduced IL-8 binding to neutrophils. Nitrotyrosine was detected in the IL-8 incubated with peroxynitrite by enzyme-linked immunosorbent assay. These findings are consistent with nitration of tyrosine by peroxynitrite with subsequent inhibition of IL-8 binding to neutrophils and a reduction in NCA and suggest that oxidants may play an important role in regulation of IL-8-induced neutrophil chemotaxis.

Endogenous nitric oxide in allergic airway disease

There has been intense research into the role nitric oxide (NO) plays in physiologic and pathologic mechanisms. The presence of NO in exhaled breath and the high concentrations in nasal airways stimulated many studies examining exhaled and nasal NO as potential markers of airway inflammation, enabling repeated monitoring of airway inflammation not possible with invasive tests (eg, bronchoscopy). In airway inflammation, NO is not merely a marker but may have anti-inflammatory and proinflammatory effects. Nasal NO measurement may be used in the noninvasive diagnosis and monitoring of nasal disease. This review was compiled by speakers who gave presentations on NO at the annual meeting of the American Academy of Allergy, Asthma, and Immunology in 1999 on exhaled and nasal NO, in vitro studies of NO, the chemistry of airway NO formation, and standardized measurement of exhaled mediators.

Inhibition of MIP-1alpha-induced human neutrophil and monocyte chemotactic activity by reactive oxygen and nitrogen metabolites

Peroxynitrite, formed by the reaction between nitric oxide (NO) and superoxide, has been implicated in the pathogenesis of numerous disease processes. Several studies have shown that peroxynitrite-induced protein nitration may compromise enzyme and protein function. We hypothesized that peroxynitrite may regulate cytokine function during inflammation. To test this hypothesis, the neutrophil and monocyte chemotactic responses of macrophage inflammatory protein-1alpha (MIP-1alpha) incubated with and without peroxynitrite were evaluated. Peroxynitrite attenuated neutrophil chemotactic activity (NCA) and monocyte chemotactic activity (MCA) by MIP-1alpha in a dose-dependent manner (P < .05). The inhibitory effects were not significant on NCA and MCA induced by leukotriene B4 or complement-activated serum incubated with peroxynitrite. The reducing agents deferoxamine, dithiothreitol, and exogenous L-tyrosine abrogated the NCA and MCA inhibition by peroxynitrite. Papa-NONOate, an NO donor, or a combination of xanthine and xanthine oxidase to generate superoxide, did not show an inhibitory effect on NCA and MCA induced by MIP-1alpha. In contrast, 3-morpholinosydnonimine (SIN-1), a peroxynitrite generator, elicited a concentration-dependent reduction in NCA and MCA induced by MIP-1alpha. Consistent with its capacity to reduce NCA and MCA, peroxynitrite treatment reduced MIP-1alpha binding to neutrophils and monocytes. Nitrotyrosine was detected in the MIP-1alpha incubated with peroxynitrite. These findings are consistent with nitration of tyrosine by peroxynitrite with subsequent inhibition of MIP-1alpha binding to neutrophils and monocytes and a reduction in NCA and MCA. These data demonstrate that peroxynitrite modulates the inflammatory cell migration by MIP-1alpha, and they suggest that oxidants may play an important role in the regulation of MIP-1alpha-induced inflammatory cell chemotaxis.

Effects of reactive oxygen and nitrogen metabolites on eotaxin-induced eosinophil chemotactic activity in vitro

Peroxynitrite, an oxidant generated by the interaction between superoxide and nitric oxide (NO), has been implicated in the etiology of numerous disease processes. Several studies have shown that peroxynitrite-induced protein nitration may compromise enzyme and protein function. We hypothesized that peroxynitrite may regulate cytokine function during inflammation. To test this hypothesis, the eosinophil chemotactic responses of eotaxin incubated with and without peroxynitrite were evaluated. Peroxynitrite attenuated eotaxin-induced eosinophil chemotactic activity (ECA) in a dose-dependent manner (P < 0.05). The inhibitory effects were not significant on ECA induced by leukotriene B(4) or complement-activated serum incubated with peroxynitrite. The reducing agents deferoxamine and dithiothreitol reversed the ECA inhibition by peroxynitrite, and exogenous L-tyrosine abrogated the inhibition by peroxynitrite. PAPA-NONOate (an NO donor) or a combination of xanthine and xanthine oxidase to generate superoxide did not show an inhibitory effect on ECA induced by eotaxin. In contrast, 3-morpholinosydnonimine, a peroxynitrite generator, caused a concentration-dependent inhibition of ECA by eotaxin. Consistent with its capacity to reduce ECA, peroxynitrite treatment reduced eotaxin binding to eosinophils. Nitrotyrosine was detected in the eotaxin incubated with peroxynitrite. These findings are consistent with nitration of tyrosine by peroxynitrite with subsequent inhibition of eotaxin binding to eosinophils and a reduction in ECA. These data demonstrate that peroxynitrite modulates the eosinophil migration by eotaxin, and suggest that oxidants may play an important role in regulation of eotaxin-induced eosinophil chemotaxis.

IL-4 and IL-13 stimulate human bronchial epithelial cells to release IL-8

Cytokine networks are important in regulating the traffic of inflammatory cells in the airways. Interleukin-8 (IL-8) released by human bronchial epithelial cells (HBECs) is thought to be of particular importance in attracting neutrophils and monocytes to sites of inflammation. Increased release of IL-8 by HBECs in response to Th-1 cytokines such as TNF alpha and IL-1 beta may be an important pathophysiologic pathway. The present study was designed to explore the role of the Th2 cytokine IL-4 and the functionally related interleukins IL-10, and IL-13 on the regulation of IL-8 release by HBECs. HBECs (passage 4-6) were cultured in LHC9/RPMI and when confluent cells were stimulated in unsupplemented medium LHCD/RPMI by IL-4, IL-10, and IL-13 at 10 ng/ml concentration for all cytokines. TNF alpha stimulation was used as a positive control. After 24 hours supernatants were collected and tested for IL-8 by a sandwich ELISA. Unstimulated HBECs spontaneously released limited amounts of IL-8 (11 +/-1 pM) and significantly increased cytokine production in response to IL-4 (42 +/- 1 pM), IL-13 (30 +/- 1 pM) and TNF (128 +/- 11 pM). Stimulation with IL-10 (11 +/- pM) did not change basal production of IL-8. When HBECs were co-stimulated with IL-4 plus TNF, the production of IL-8 was further increased (204 +/- 5 pM). In contrast, IL-10 attenuated the effect of TNF during co-stimulation (82 +/- 5 pM). IL-13 did not affect the release of IL-8 induced by TNF (111 +/- 9 pM). Northern blot analysis of IL-8 mRNA levels showed the highest induction of IL-8 mRNA in HBECs co-stimulated with TNF and IL-4. We conclude from our study that IL-4 directly induces IL-8 release from HBECs and amplifies the release of IL-8 in response to TNF alpha. IL-13 is less active and IL-10 has an inhibitory effect. Airway epithelial cells are able to interact, therefore, with products of both Th1 and Th2 cells with respect to modulating release of IL-8.

Smoke extract stimulates lung fibroblasts to release neutrophil and monocyte chemotactic activities

Accumulation of monocytes and neutrophils and fibrous distortion of the airway are characteristics of airway disease secondary to smoking. The presence of inflammatory cells and fibrosis correlate, and, therefore, we postulated that lung fibroblasts might release chemotactic activity for neutrophils and monocytes in response to smoke extract. To test this hypothesis, human fetal lung (HFL1) fibroblasts were cultured, and the supernatant fluid was evaluated for neutrophil (NCA) and monocyte (MCA) chemotactic activities with a blind well chamber technique. HFL1 fibroblasts released chemotactic activity in response to smoke extract in a dose- and time-dependent manner (P < 0.05). Checkerboard analysis showed that the activity was predominantly chemotactic. Partial characterization of the released chemotactic activity revealed that the activity was partly heat labile, trypsin sensitive, and ethyl acetate extractable. Lipoxygenase inhibitors and cycloheximide inhibited the release of both NCA and MCA. Molecular-sieve chromatography revealed that NCA and MCA were heterogeneous. NCA was inhibited by anti-human interleukin (IL)-8 and anti-granulocyte colony-stimulating factor antibodies and a leukotriene (LT) B(4)-receptor antagonist. Anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) and anti-monocyte chemoattractant protein (MCP)-1 antibodies and an LTB(4)-receptor antagonist inhibited MCA. Immunoreactive IL-8, granulocyte colony-stimulating factor, GM-CSF, and MCP-1 significantly increased in culture supernatant fluid in response to smoke extract. Finally, smoke extract augmented the expression of mRNAs of IL-8, GM-CSF, and MCP-1. These data demonstrate that lung fibroblasts release NCA and MCA in response to smoke extract and suggest that lung fibroblasts may modulate the inflammatory cell recruitment into the lung.

Effects of reactive oxygen and nitrogen metabolites on MCP-1-induced monocyte chemotactic activity in vitro

Peroxynitrite, an oxidant generated by the interaction between superoxide and nitric oxide (NO), can nitrate tyrosine residues, resulting in compromised protein function. Monocyte chemoattractant protein-1 (MCP-1) is a chemokine that attracts monocytes and has a tyrosine residue critical for function. We hypothesized that peroxynitrite would alter MCP-1 activity. Peroxynitrite attenuated MCP-1-induced monocyte chemotactic activity (MCA) in a dose-dependent manner (P < 0.05) but did not attenuate leukotriene B4 or complement-activated serum MCA. The reducing agents dithionite, deferoxamine, and dithiothreitol reversed the MCA inhibition by peroxynitrite, and exogenous L-tyrosine abrogated the inhibition by peroxynitrite. PAPA-NONOate, an NO donor, or superoxide generated by xanthine and xanthine oxidase did not show an inhibitory effect on MCA induced by MCP-1. The peroxynitrite generator 3-morpholinosydnonimine caused a concentration-dependent inhibition of MCA by MCP-1. Peroxynitrite reduced MCP-1 binding to monocytes and resulted in nitrotyrosine formation. These findings are consistent with nitration of tyrosine by peroxynitrite, with subsequent inhibition of MCP-1 binding to monocytes, and suggest that peroxynitrite may play a role in regulation of MCP-1-induced monocyte chemotaxis.

Alternative therapies for chronic bronchitis

Alternative therapies for chronic bronchitis are therapies in which clinical efficacy is not well established. These can be broadly divided into expectorants, mucolytics, mucokinetics, antiproteases, antioxidants, and immunostimulants. Data supporting these therapies may be present in disorders clinically similar to chronic bronchitis, such as cystic fibrosis. Alternatively, these therapies may be based on clinical observations or in vitro studies that suggest a potential therapeutic benefit. Establishment of these therapies is likely to require more extensive investigation before their use is routinely recommended. Until such data is available, the clinician can only use his or her clinical judgement regarding the likely risk-benefit ratio.

Effects of reactive oxygen and nitrogen metabolites on RANTES- and IL-5-induced eosinophil chemotactic activity in vitro

Eosinophils and increased production of nitric oxide (NO) and superoxide, components of peroxynitrite, have been implicated in the pathogenesis of a number of allergic disorders including asthma. Peroxynitrite induced protein nitration may compromise enzyme and protein function. We hypothesized that peroxynitrite may modulate eosinophil migration by modulating chemotactic cytokines. To test this hypothesis, the eosinophil chemotactic responses of regulated on activation, normal T cell expressed and secreted (RANTES) and interleukin (IL)-5 incubated with and without peroxynitrite were evaluated. Peroxynitrite-attenuated RANTES and IL-5 induced eosinophil chemotactic activity (ECA) in a dose-dependent manner (P < 0.05) but did not attenuate leukotriene B4 or complement-activated serum ECA. The reducing agents deferoxamine and dithiothreitol reversed the ECA inhibition by peroxynitrite, and exogenous L-tyrosine abrogated the inhibition by peroxynitrite. PAPA-NONOate, a NO donor, or superoxide generated by lumazine or xanthine and xanthine oxidase, did not show an inhibitory effect on ECA. The peroxynitrite generator, 3-morpholinosydnonimine, caused a concentration-dependent inhibition of ECA. Peroxynitrite reduced RANTES and IL-5 binding to eosinophils and resulted in nitrotyrosine formation. These findings are consistent with nitration of tyrosine by peroxynitrite with subsequent inhibition of RANTES and IL-5 binding to eosinophils and suggest that peroxynitrite may play a role in regulation of eosinophil chemotaxis.

IL-4 induces ICAM-1 expression in human bronchial epithelial cells and potentiates TNF-alpha

Interleukin (IL)-4 is thought to contribute to the Th2 type of immune response and hence the development of allergic reactions such as asthma. In asthmatic patients, the airway epithelium expresses increased amounts of the cell surface adhesion molecule intercellular adhesion molecule (ICAM)-1 (CD54). One cytokine capable of inducing ICAM-1 in airway epithelial cells, tumor necrosis factor-alpha (TNF-alpha), is present in asthma. This study evaluated if IL-4 either alone or together with TNF-alpha costimulation might modulate CD54 expression by human bronchial epithelial cells (HBECs). CD54 positivity increased in response to IL-4 (16 +/- 2% positive vs. 3 +/- 1%, P < 0.01); greater induction of CD54 resulted from TNF-alpha (45 +/- 2%, P < 0.001). Costimulation with TNF-alpha plus IL-4 further augmented expression (56 +/- 1%, P < 0.05). Immunoperoxidase results were confirmed by flow cytometry. RT-PCR revealed no increase in ICAM-1 mRNA expression under control conditions or after stimulation with IL-4 alone. TNF-alpha increased IL-4 mRNA, and IL-4 potentiated this. Functionally, IL-4 augmented the adhesion of THP-1 monocyte/macrophage cells to monolayers of HBECs both alone and in the presence of TNF-alpha. We conclude that 1) IL-4 augments epithelial cell ICAM-1 expression, 2) IL-4 potentiates the adhesion of THP-1 monocyte/macrophage cells to epithelial cells, and 3) modulation of epithelial cell ICAM-1 expression by IL-4 may play a role in the immunopathology of bronchial asthma.

Superoxide released from neutrophils causes a reduction in nitric oxide gas

Exhaled nitric oxide (NO) is increased in some inflammatory airway disorders but not in others such as cystic fibrosis and acute respiratory distress syndrome. NO can combine with superoxide (O-2) to form peroxynitrite, which can decompose into nitrate. Activated polymorphonuclear neutrophils (PMNs) releasing O-2 could account for a reduction in exhaled NO in disorders such as cystic fibrosis. To test this hypothesis in vitro, we stimulated confluent cultures of LA-4 cells, a murine lung epithelial cell line, to produce NO. Subsequently, human PMNs stimulated to produce O-2 were added to the LA-4 cells. A gradual increase in NO in the headspace above the cultures was observed and was markedly reduced by the addition of PMNs. An increase in nitrate in the culture supernatant fluids was measured, but no increase in nitrite was detected. Superoxide dismutase attenuated the PMN effect, and xanthine/xanthine oxidase reproduced the effect. No changes in epithelial cell inducible NO synthase protein or mRNA were observed. These data demonstrate that O-2 released from PMNs can decrease NO by conversion to nitrate and suggest a potential mechanism for modulation of NO levels in vivo.

Respiratory tract inflammation in swine confinement workers studied using induced sputum and exhaled nitric oxide

OBJECTIVE

To further define the asthma-like syndrome seen in swine confinement workers.

DESIGN

A cross-sectional study was performed at a swine confinement facility in rural Nebraska and at the University of Nebraska Medical Center, Omaha, Nebraska.

PARTICIPANTS

24 swine confinement workers and 14 urban normal control subjects. All subjects completed a questionnaire concerning respiratory complaints. We performed hypertonic saline challenges on the swine confinement workers and control subjects in order to induce expectoration of sputum. Cell counts and cell differentials were determined in the induced sputum samples. Nasal, mean, and peak exhaled nitric oxide was measured in both groups. Spirometry was also done.

RESULTS

Swine confinement workers were significantly more likely to report wheezing, cough, and sinusitis symptoms than controls (p = .003). Macrophages were significantly elevated in the induced sputum samples of the swine confinement workers vs the control subjects (0.59 macrophages/mL +/- 0.1 SEM vs 0.36 +/- .16; p = .006), while there was no difference in numbers of neutrophils. No eosinophils were observed. A small elevation in mean exhaled nitric oxide was seen in the swine confinement workers compared to normal controls (11.7 ppb +/- 0.6 SEM vs 10.2 +/- 1.6; p = 0.023). Spirometry values did not differ statistically between swine confinement workers and the control group.

CONCLUSIONS

Swine confinement workers have signs and symptoms of lower respiratory tract inflammation when studied using induced sputum and exhaled nitric oxide. Findings in the swine confinement workers differ from those in asthmatics and chronic bronchitis.

Methotrexate inhibition of inducible nitric oxide synthase in murine lung epithelial cells in vitro

Nitric oxide (NO) is produced in lung epithelial cells by nitric oxide synthases (NOSs), which can enhance inflammation and edema formation. The inducible NOS (iNOS, type II NOS) has been shown to be increased in lung disorders such as asthma. Therapy for asthma includes antiinflammatory agents such as corticosteroids and antineoplastic agents such as methotrexate (MTX). We hypothesized that NO production by epithelial cells in vitro would be attenuated by MTX, and that this effect would be additive with corticosteroids. In order to test this hypothesis, cells from the murine lung epithelial-cell line LA-4 were cultured to confluence and stimulated to express iNOS and produce NO by cytomix, a combination of human tumor necrosis factor-alpha (TNF-alpha), human interleukin-1beta (IL-1beta) and murine interferon-gamma (IFN-gamma). Nitrite and nitrite + nitrate were measured in the culture supernatant fluids as an index of NO production. MTX caused a dose- and time-dependent inhibition of nitrite and nitrite + nitrate (P < 0.05, all comparisons). Importantly, the inhibition of NO production by MTX (10(-3) M) was additive with dexamethasone (10(-5) to 10(-9) M), but cyclophosphamide, bleomycin, and cytosine-beta-D-arabinofuranoside (Ara-C), other antineoplastic agents, caused no inhibition of NO production. To investigate the mechanism of NO inhibition with MTX, we added tetrahydrobiopterin, which reversed the inhibition. MTX had no effect on the expression of iNOS on Western blotting or iNOS mRNA on Northern blotting. These data show that MTX inhibits NO production by iNOS in murine lung epithelial cells in vitro and that MTX produces added inhibition with corticosteroids, and suggest a potential strategy for reducing NO production in vivo.

Mutual inhibition by TGF-beta and IL-4 in cultured human bronchial epithelial cells

The airway epithelial cell may play a role as an effector cell, releasing various cytokines and extracellular matrix components in immune responses, inflammation, and wound repair processes, thus contributing to cytokine "networks." The cytokines transforming growth factor (TGF)-beta and interleukin (IL)-4 are though to have pivotal roles in airway diseases, with IL-4 having proinflammatory actions and TGF-beta generally regarded to mediate repair and to attenuate immune responses. In asthma, where IL-4 and TGF-beta are thought to contribute to the inflammatory process and repair, respectively, interactions between these cytokines are likely to be of importance. Therefore, we studied the potential interaction of both cytokines by measuring IL-8 and fibronectin release by cultured human bronchial epithelial cells (HBECs). IL-4 is capable of inducing IL-8 release from HBECs. This effect of IL-4 can be blocked by the concurrent presence of the cytokine TGF-beta. In contrast, TGF-beta had a modest inconsistent stimulatory effect on IL-8 release by itself and had no effect on the IL-8 release induced by tumor necrosis factor (TNF)-alpha. An antagonistic effect of IL-4 and TGF-beta was also observed on HBEC fibronectin release. TGF-beta stimulated fibronectin release, and IL-4 was able to inhibit this. This effect was not due to a redistribution of fibronectin but appeared to be due to a true reduction in synthesis. Consistent with this, IL-4 and TGF-beta effects on IL-8 and fibronectin release were paralleled by changes in mRNA levels. The ability of TGF-beta to block IL-4-induced IL-8 release is certainly not the only mechanism to inhibit IL-8 release because dexamethasone was capable of inhibiting both TNF-alpha- and IL-4-induced release of IL-8. These results indicate that TGF-beta and IL-4 can have mutually inhibitory effects. The balance determined by this reciprocal inhibition may play an important role in regulating inflammation repair and in diseases such as asthma.

Smoking cessation is associated with an increase in exhaled nitric oxide

STUDY OBJECTIVES

Nitric oxide (NO), a gas produced by cells lining the respiratory tract, has been reported to be decreased in the exhaled air of cigarette smokers. We hypothesized that smoking cessation would result in an increase in exhaled NO.

DESIGN

Comparison of exhaled NO measured from nonsmokers, cigarette smokers, and smokers after smoking cessation.

SETTING

University outpatient smoking cessation clinic.

PATIENTS OR PARTICIPANTS

Twenty-five cigarette smokers and 23 normal, nonsmokers.

INTERVENTIONS

Exhaled NO was measured by three techniques: (1) a peak oral method; (2) a mean oral method; and (3) a nasal method. The smokers were given nicotine patches and instructed to return after 1 and 8 weeks. The exhaled NO determinations were repeated on each visit.

MEASUREMENTS AND RESULTS

Compared with nonsmokers, smokers had decreased NO levels measured by all three methods (p<0.05, each comparison). Nineteen smokers returned after 1 week. Fourteen were successfully abstinent from cigarettes and their exhaled NO increased compared with baseline (p<0.01 for each method) but not in the five subjects who had not successfully quit smoking (p>0.05 for each method). Ten subjects returned after 8 weeks. The exhaled NO levels increased further and were not significantly different from the normal nonsmokers for the peak oral and nasal NO methods (p>0.2), but were still lower than the normal nonsmoker mean oral NO (p=0.018).

CONCLUSIONS

These data demonstrate that smoking cessation is associated with an increase in exhaled NO.

Aprotinin but not tranexamic acid inhibits cytokine-induced inducible nitric oxide synthase expression

Cell expression of inducible nitric oxide synthase (iNOS) is increased by cytokines, which results in high endogenous concentrations of nitric oxide (NO) and has been implicated in organ injury, including myocardial reperfusion injury. Serine protease inhibitors reduce cytokine-induced iNOS expression. The protease inhibitors aprotinin and tranexamic acid, which are used to reduce blood loss after cardiac surgery, were evaluated in vitro on cytokine-induced iNOS expression and the resulting NO production to demonstrate the relative antiinflammatory effects of each drug. A murine bronchial epithelial cell line (LA-4) was stimulated with cytomix (tumor necrosis factor alpha, interleukin 1beta, and gamma-interferon) with or without aprotinin, tranexamic acid, or N-alpha-tosyl-L-lysine chloromethyl ketone (TLCK; a protease inhibitor). The resultant iNOS expression was measured by using Northern blot analysis and cell supernatant nitrite concentrations (in aqueous media, NO is oxidized primarily to nitrite, NO2-) by chemiluminescence. Nitrite concentrations in the supernatant were significantly increased by cytomix, not affected by any concentration of tranexamic acid, but significantly (P < 0.05) reduced by aprotinin and TLCK. Consistent with the nitrite reduction, aprotinin significantly (P < 0.05) reduced cytokine-induced iNOS expression, while tranexamic acid had no effect. Aprotinin but not tranexamic acid reduces endogenous cytokine-induced NO production by inhibiting iNOS expression. Since increased endogenous NO concentrations secondary to iNOS activation have been implicated in organ injury, aprotinin may have clinical benefits when compared with tranexamic acid.

Nitric oxide

Nitric oxide (NO) is a gas with diverse biological activities produced from arginine by NO synthases. It is capable of interacting with a number of molecules, most notably superoxide, forming peroxynitrite, which, in turn, can mediate bactericidal or cytotoxic reactions. Nitric oxide also mediates smooth muscle relaxation, neurotransmission, and modulation of inflammation in a number of organ systems and pathophysiologic conditions. Modulation of NO by administration of inhaled NO for respiratory distress syndromes and infusion of NO synthase inhibitors in bacterial sepsis are ongoing. Levels of exhaled NO are being evaluated for their utility in assessing inflammation in respiratory disorders such as asthma.

Cigarette smoke induces interleukin-8 release from human bronchial epithelial cells

Cigarette smoking causes the development of chronic bronchitis and chronic obstructive pulmonary disease. We hypothesized that exposure to cigarette smoke might initiate release of inflammatory mediators by bronchial epithelial cells. To evaluate this, the effect of cigarette smoke extract (CSE) on IL-8 release from cultured human bronchial epithelial cells was examined. CSE augmented IL-8 release from bronchial epithelial cells in a concentration- and time-dependent manner. Most of the augmenting activity of CSE on IL-8 release from bronchial epithelial cells was lost after volatilization or lyophilization treatment. Two major volatile factors in cigarette smoke, acrolein and acetaldehyde, augmented IL-8 release. Four cell strains were tested and showed increased IL-8 release in response to CSE. In addition, bronchoalveolar lavage was performed on 11 nonsmokers and 12 smokers. IL-8 concentration was greater in the proximal, bronchial samples than in distal, alveolar samples, and IL-8 in BAL from smokers was higher than in BAL from nonsmokers. There was a significant correlation between IL-8 concentration and neutrophil count in bronchial samples of BAL fluid. These data support the hypothesis that exposure to cigarette smoke may induce bronchial epithelial cells to release IL-8 and that this may contribute to airway inflammation in smokers.

Aprotinin is associated with a decrease in nitric oxide production during cardiopulmonary bypass

BACKGROUND

Cardiopulmonary bypass (CPB) is associated with an increase in airway nitric oxide (NO), plasma levels of tumor necrosis factor-alpha (TNF-alpha), and interleukin-1 beta. Cytokine induction of the inducible form of nitric oxide synthase (iNOS) has been implicated in organ injury. In addition, serine protease inhibitors reduce cytokine-induced iNOS expression. Aprotinin, a serine protease inhibitor, has been demonstrated to exhibit significant antiinflammatory effects. We hypothesized that aprotinin administration during CPB would significantly reduce endogenous airway NO production.

METHODS

Airway NO was measured during CPB in 10 patients receiving aprotinin and in 10 control subjects. In vitro, aprotinin was added to cultures of a murine lung epithelial cell line and was stimulated with cytomix, a combination of TNF, interleukin-1, and interferon-gamma.

RESULTS

Airway NO concentration was increased after 50 minutes of CPB duration compared with that measured at 5 minutes in control subjects (53 +/- 5 versus 19 +/- 3 parts per billion, p < 0.05) but not in the aprotinin group (21 +/- 6 versus 15 +/- 3 parts per billion). Aprotinin reduced nitrite concentrations in the cell culture supernatant fluids after 24 hours (cytomix, 21.5 +/- 2.1 mumol/L; cytomix plus aprotinin, 2.7 +/- 0.6 mumol/L, p < 0.05). Immunohistochemistry showed a reduction in cytokine-induced iNOS expression and Northern blot analysis showed a decrease in iNOS mRNA.

CONCLUSIONS

These data demonstrate that aprotinin reduces NO production in vivo and reduces cytokine-induced iNOS expression in vitro.

Human lung mononuclear cells induce nitric oxide synthase in murine airway epithelial cells in vitro: role of TNFalpha and IL-1beta

Nitric oxide (NO) is a gas released by the airway epithelium, but the mechanism regulating NO release is unclear. We hypothesized that lung mononuclear cell release of tumor necrosis factor alpha (TNF) and interleukin-1beta (IL-1) would induce epithelial cells to release NO. Lung mononuclear cells were obtained from seven normal volunteers by bronchoalveolar lavage and cultured with Escherichia coli lipopolysaccharide for 24 h. The mononuclear cell culture-conditioned media (M-CM) were then applied to cultures of the murine lung epithelial cell line, LA-4. Nitrite and nitrite + nitrate concentrations were 0.9 +/- 0.1 and 11.8 +/- 2.4 microM in the M-CM. Culturing LA-4 cells line with the M-CM (1:10 dilution) resulted in a marked and time-dependent increase in nitrite or nitrite + nitrate compared with LA-4 cells cultured in media alone (2.4 +/- 0.5 versus 0.9 +/- 0.1 microm and 16.6 +/- 0.6 versus 11.8 +/- 2.4 microM after 24 h). Antibodies to TNF and/or IL-1 significantly reduced the nitrite or nitrite + nitrate concentrations and the concentrations of TNF and IL-1 in the M-CM correlated with nitrite concentrations in the LA-4 culture supernatant fluids (r2 = 0.848 and 0.956). Inducible nitric oxide synthase (iNOS) protein and mRNA examined by immunohistochemistry and Northern blot analysis revealed a marked elevation in the cells cultured with the M-CM which was significantly reduced by TNF and IL-1 antibodies. These data demonstrate that mononuclear cells can stimulate LA-4 cells to express iNOS by releasing TNF and IL-1.

Differing effects of aprotinin and epsilon-aminocaproic acid on cytokine-induced inducible nitric oxide synthase expression

BACKGROUND

Cell expression of inducible nitric oxide synthase (iNOS) is increased by cytokines, resulting in high endogenous levels of nitric oxide. Expression of iNOS has been implicated in organ injury, including myocardial reperfusion injury. Serine protease inhibitors reduce cytokine-induced iNOS expression. The protease inhibitors aprotinin and epsilon-aminocaproic acid (EACA), used to reduce blood loss after cardiac operations, were evaluated in vitro on cytokine-induced iNOS expression and nitric oxide production.

METHODS

A murine bronchial epithelial cell line was stimulated with a mixture of cytokines (tumor necrosis factor-alpha, interleukin-1 beta, and interferon-gamma) with or without aprotinin or EACA. The resultant iNOS expression was measured by northern blot analysis, and nitric oxide production was assessed by cell supernatant nitrite levels.

RESULTS

Nitrite concentrations in the supernatant were significantly increased after cytokine stimulation; they were not affected by any concentration of EACA but were significantly (p < 0.05) reduced by aprotinin. Aprotinin significantly (p < 0.05) reduced cytokine-induced iNOS expression, whereas EACA had no effect.

CONCLUSIONS

Aprotinin, but not EACA, reduces cytokine-induced nitric oxide production by inhibition of iNOS expression. Because increased endogenous nitric oxide levels secondary to iNOS activation have been implicated in organ injury, aprotinin may have clinical benefit compared with EACA when used for cardiac operations.

Psychological testing variables as predictors of return to work by chronic pain patients

After multidisciplinary pain treatment, pretreatment psychological testing variables were compared for 20 chronic pain patients who were working and 42 who were not working. Symptom Checklist-90-R scores for Depression, Anxiety, Phobic Anxiety, Psychoticism, Global Severity, and Positive Symptom Distress were lower for working subjects as were those on the Beck Depression Inventory. In contrast, workers scored higher on self-efficacy to manage pain, self-efficacy to function, self-efficacy to manage other symptoms, and over all self-efficacy.

Inhibition of inducible nitric oxide synthase expression by interleukin-4 and interleukin-13 in human lung epithelial cells

Nitric oxide produced by the inducible enzyme, nitric oxide synthase (iNOS), is implicated in immunological and inflammatory processes. We determined the effects of T-helper (Th)2-derived cytokines on the induction of iNOS from an epithelial A549 cell line and human airway epithelial cells stimulated by a mixture of interleukin-1 beta (IL-1 beta), interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha). Interleukin-4 (IL-4) and interleukin-13 (IL-13) but not interleukin-10 (IL-10) inhibited both iNOS mRNA expression and nitrite release in A549 cells. On human airway epithelial cells, IL-4 and IL-13 reduced iNOS mRNA expression. Dexamethasone also inhibited both iNOS expression and nitrite release. Th2 cytokines, IL-4 and IL-13, inhibit iNOS upregulation by Th1 cytokines, indicating an important reciprocal role of Th1 and Th2 T-cell subsets on lung epithelial cells.

Aprotinin reduces interleukin-8 production and lung neutrophil accumulation after cardiopulmonary bypass

Pulmonary neutrophil entrapment and resultant oxidative injury is thought to be the primary mechanism of cardiopulmonary bypass (CPB) induced lung injury. Interleukin-8 (IL-8), a potent neutrophil chemoattractant induced by cytokines, including tumor necrosis factor-alpha (TNF), is found in increased concentrations in bronchial alveolar lavage fluid (BALF) in lung inflammation. Since aprotinin reduces TNF release during CPB, the effects of aprotinin on BALF IL-8 concentrations and neutrophil levels were determined after CPB in adult humans. Study patients were equally divided into a control group (n = 8, Group 1) and an aprotin-intreated group (n = 8, Group 2). In vitro neutrophil chemotaxis was done with volunteer neutrophils using three different chemoattractants: 1) N-formyl-1-methionyl-1-leucyl-1-phenylalanine (FMLP); 2) the supernatant of a human bronchial epithelial cell culture line, A549, after 24 h of TNF stimulation with or without aprotinin or N-alpha-tosyl-L-lysine chloromethyl ketone (TLCK) (a potent protease inhibitor), and 3) BALF. Aprotinin treatment significantly (P < 0.05) reduced post-CPB BALF IL-8 concentrations and percentage of neutrophils. In vitro, BALF from Group 1 had significantly greater chemotactic ability when compared with Group 2. The TNF stimulated A549 cell culture supernatant had significantly (P < 0.05) greater chemotactic ability than control supernatant, while aprotinin and TLCK significantly (P < 0.05) reduced this chemotactic ability. These results demonstrate that aprotinin blunts IL-8 production and reduces neutrophil lung accumulation post-CPB.

The effect of alcohol ingestion on exhaled nitric oxide

The concentration of nitric oxide (NO) is increased in the exhaled air of patients with inflammatory lung diseases, including asthma, possibly reflecting cytokine-mediated chronic airway inflammation. Endogenous NO is generated from L-arginine by the action of several types of NO synthase (NOS). NOS have structural similarities with cytochrome P450 reductases. Alcohol decreases exhaled NO in animals, but this has not previously been investigated in man. We studied the effect of alcohol ingestion in nine asthmatic and 12 normal subjects, measuring the peak concentration of exhaled NO using a modified chemiluminescence analyser. A significant decrement in NO occurred in asthmatic patients (mean +/- SEM before ethanol 204 +/- 58 to 158 +/- 59 parts per billion (ppb) after ethanol; p < 0.02), without significant change in the normal subjects (122 +/- 14 to 114 +/- 15 ppb). Thus, in our study, alcohol decreased exhaled nitric oxide in asthmatic subjects but not in normal individuals. This may reflect preferential action on inducible nitric oxide synthase which is expressed in asthmatic airways. An inhibitory effect of ethanol on inducible nitric oxide synthase may contribute towards the effect of alcohol in asthma.

Measurement of exhaled nitric oxide by three different techniques

The purpose of the study was to compare exhaled nitric oxide (NO) determined by three techniques. Ninety-one subjects performed a slow vital capacity maneuver: (1) through the mouth directly into a NO chemiluminescence analyzer (peak oral NO), (2) through the mouth into a collection bag (mean oral NO), and (3) through the nose into a collection bag (mean nasal NO). Peak oral NO was higher in patients with asthma (n = 18, 174.2 +/- 27.0 ppb), but lower in smokers (n = 36, 39.6 +/- 4.8 ppb) compared with nonsmoking control subjects (n = 23, 105.5 +/- 8.4 ppb, p < 0.05 both comparisons). Mean oral NO levels were significantly lower than peak oral NO levels (p < 0.05), but still higher in patients with asthma in comparison with nonsmoking healthy control subjects and asymptomatic smokers (27.2 +/- 3.5 versus 14.5 +/- 1.1 and 7.3 +/- 0.7 ppb, respectively, p < 0.05). In contrast, there was no significant difference in mean nasal NO levels between the three groups. Peak oral NO and mean oral NO levels correlated (r = 0.772, p < 0.0001). Determination of exhaled oral NO levels is qualitatively independent of the technique used, but nasal exhalation may affect NO determination in conditions associated with airway inflammation.

Cardiopulmonary function and autologous bone marrow transplantation: results and predictive value for respiratory failure and mortality. The University of Nebraska Medical Center Bone Marrow Transplantation Pulmonary Study Group

Cardiopulmonary complications are a major cause of morbidity and mortality in patients undergoing high-dose therapy with stem cell transplant support. Since exercise tolerance testing (ETT) assesses the cardiopulmonary reserve of an individual, we hypothesized that ETT performed prior to transplant would predict respiratory failure and mortality and would be a superior predictor over resting cardiopulmonary function tests. We performed a retrospective study of 191 lymphoma patients who underwent ETT prior to transplant between 1 June 1990 and 31 December 1992 and compared the results of ETT with resting pulmonary function tests (PFT) and resting cardiac ejection fraction (EF). ETT revealed that cardiac, pulmonary and combined cardiopulmonary limitation were observed in 31, 20 and 16% of the patients, respectively, with a gas diffusion-type limitation being the most common exercise limitation. Resting PFT were abnormal in 58% of patients with a diffusion defect being the most common abnormality. Low EF was observed in 6.8% of patients. Twelve patients eventually required mechanical ventilation post-transplant with only the resting diffusion PFT predictive of this complication. There were five early deaths that were attributable to respiratory failure and neither resting nor ETT studies were predictive of these deaths. ETT and EF performed prior to transplant in lymphoma patients undergoing autologous transplant do not predict for either respiratory failure or short-term mortality. Our findings may be due to the rather low incidence of respiratory failure (6.3%) and low early mortality from cardiopulmonary complications (2.6%) seen in our patient population.

Loop diuretics attenuate bradykinin-induced increase in clearance of macromolecules in the oral mucosa

The purpose of this study was to determine whether loop diuretics attenuate bradykinin-induced increase in clearance of macromolecules in the oral mucosa in situ and, if so, to start to determine the mechanisms that mediated these responses. By using intravital microscopy, we found that bradykinin induced a significant concentration-dependent increase in fluorescein isothiocyanate-labeled dextran (mol mass 70 kDa) leaky site formation in the hamster cheek pouch. These responses were significantly attenuated by topical application of two structurally distinct loop diuretics, furosemide and ethacrynic acid, onto the cheek pouch (P < 0.05). Hydrochlorothiazide, a nonloop diuretic, had no significant effects on bradykinin-induced responses. Furosemide had no significant effects on adenosine-induced leaky site formation. Application of bradykinin after furosemide, but not after hydrochlorothiazide, was associated with a significant concentration-dependent decrease in bradykinin-like immunoreactivity in the cheek pouch suffusate (P < 0.05). Prostaglandins and changes in vasomotor tone did not modulate the effects of furosemide on bradykinin-induced responses. These data indicate that loop diuretics attenuate bradykinin-induced increase in clearance of macromolecules in the oral mucosa in a specific fashion, probably by amplifying local bradykinin catabolism. We suggest that topical loop diuretics could be useful in the treatment of oral mucosa inflammation elicited by bradykinin.

Antiproteases attenuate the release of neutrophil chemotactic activity from bronchial epithelial cells induced by smoke

The released neutrophil chemotactic activity (NCA) from bronchial epithelial cells (BECs) in response to smoke extract was evaluated by reverse-phase, high-performance liquid chromatography (RP-HPLC) and the involvement of proteolytic activity was assessed for the release of NCA from BECs. Smoke extract stimulated the release of NCA (55.3 +/- 5.2 vs. 17.3 +/- 4.1 cells per high-power field [HPF], p < .001). The released activity determined by RP-HPLC analysis was 15-hydroxyeicosatetraenoic acid and leukotriene B4. Several structurally and functionally different serine protease inhibitors, including alpha-1-protease inhibitor (alpha-1-PI), chloromethyl ketone (CK) derivatives, N-tosyl-L-lysine CK (TLCK), methoxysuccinyl-Ala-Ala-Pro-Val CK (SPCK), N-alpha-tosyl-L-phenylalanine CK (TPCK), and N-alpha-p-tosyl-L-arginine methyl ester hydrochloride (TAME), attenuated the release of NCA (P < .01) in a dose-dependent fashion. Leupeptin, a cysteine protease inhibitor, has only a small effect on the release of NCA (p < .05), and phosphoramidon, a neutral endopeptidase inhibitor, had no effect. The measurement of proteolytic enzyme activity using synthetic substrate S-2288 revealed that smoke extract significantly (p < .05) augmented the serine protease activity in BEC layers. Culture supernatant fluids and cell lysates of BECs in response to smoke extract solubilized 14C-labeled casein. These results suggest that BECs may release lipoxygenase-derived NCA in response to smoke extract and that the release of NCA may involve the activation of proteolytic activity of BECs which was inhibited by serine protease inhibitors.

Glucocorticoid reduction of bronchial epithelial inflammation during cardiopulmonary bypass

Tumor necrosis factor-alpha (TNF-alpha) is released in inflammatory lung conditions, raising airway nitric oxide (NO) concentrations through the cytokine-mediated induction of nitric oxide synthase (NOS). Cardiopulmonary bypass (CPB) creates an inflammatory state, characterized by the release of TNF-alpha, that may result in lung injury following CPB. This study measured plasma levels of TNF-alpha and interleukin-6 (IL-6) as well as airway NO concentrations during CPB, and the effect of methylprednisolone (MPSS) on the levels of these inflammatory products. Twenty adult males scheduled for coronary artery bypass grafting (CABG) were anesthetized and randomized to a group given MPSS at 1 gm intravenously 5 min before CPB (Group S) or a group not given MPSS (Group N). Plasma levels of TNF-alpha and IL-6 were measured by enzyme-linked immunosorbent assay (ELISA) and the airway NO concentration by chemiluminescence. TNF-alpha was significantly (p < 0.05) increased at 30 min after the termination of CPB, while IL-6 was significantly (p < 0.05) increased at 50 min into CPB and 30 min after the end of CPB in Group N as compared with controls in the same group and with Group S at the same time intervals. A group of 10 patients undergoing repair of infrarenal aortic aneurysms, which served as a control group for plasma levels of TNF-alpha, showed no significant changes in TNF-alpha concentrations at any time during aneurysm repair. Airway NO increased significantly (p < 0.01) in Group N as compared with Group S at 5, 20, 35, and 50 min of CPB.(ABSTRACT TRUNCATED AT 250 WORDS)