One-Year In Situ Incubation of Pyrite at the Deep Seafloor and Its Microbiological and Biogeochemical Characterizations.

In this study, we performed a year-long in situ incubation experiment on a common ferrous sulfide (Fe-S) mineral, pyrite, at the oxidative deep seafloor in the hydrothermal vent field in the Izu-Bonin arc, Japan, and characterized its microbiological and biogeochemical properties to understand the microbial alteration processes of the pyrite, focusing on Fe(II) oxidation. The microbial community analysis of the incubated pyrite showed that the domain Bacteria heavily dominated over Archaea compared with that of the ambient seawater, and Alphaproteobacteria and Gammaproteobacteria distinctively codominated at the class level. The mineralogical characterization by surface-sensitive Fe X-ray absorption near-edge structure (XANES) analysis revealed that specific Fe(III) hydroxides (schwertmannite and ferrihydrite) were locally formed at the pyrite surface as the pyrite alteration products. Based on the Fe(III) hydroxide species and proportion, we thermodynamically calculated the pH value at the pyrite surface to be pH 4.9 to 5.7, indicating that the acidic condition derived from pyrite alteration was locally formed at the surface against neutral ambient seawater. This acidic microenvironment at the pyrite surface might explain the distinct microbial communities found in our pyrite samples. Also, the acidity at the pyrite surface indicates that the abiotic Fe(II) oxidation rate was much limited at the pyrite surface kinetically, 3.9 × 103- to 1.6 × 105-fold lower than that in the ambient seawater. Moreover, nanoscale characterization of microbial biomolecules using carbon near-edge X-ray absorption fine-structure (NEXAFS) analysis showed that the sessile cells attached to pyrite excreted the acidic polysaccharide-rich extracellular polymeric substances at the pyrite surface, which can lead to the promotion of biogenic Fe(II) oxidation and pyrite alteration. IMPORTANCE Pyrite is one of the most common Fe-S minerals found in submarine hydrothermal environments. Previous studies demonstrated that the Fe-S mineral can be a suitable host for Fe(II)-oxidizing microbes in hydrothermal environments; however, the details of microbial Fe(II) oxidation processes with Fe-S mineral alteration are not well known. The spectroscopic and thermodynamic examination in the present study suggests that a moderately acidic pH condition was locally formed at the pyrite surface during pyrite alteration at the seafloor due to proton releases with Fe(II) and sulfidic S oxidations. Following previous studies, the abiotic Fe(II) oxidation rate significantly decreases with a decrease in pH, but the biotic (microbial) Fe(II) oxidation rate is not sensitive to the pH decrease. Thus, our findings clearly suggest that the pyrite surface is a unique microenvironment where abiotic Fe(II) oxidation is limited and biotic Fe(II) oxidation is more prominent than that in neutral ambient seawater.

Identification of chronic obstructive pulmonary disease subgroups in 13 Asian cities.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a heterogeneous condition that can differ in its clinical manifestation, structural changes and response to treatment. OBJECTIVE: To identify subgroups of COPD with distinct phenotypes, evaluate the distribution of phenotypes in four related regions and calculate the 1-year change in lung function and quality of life according to subgroup. METHODS: Using clinical characteristics, we performed factor analysis and hierarchical cluster analysis in a cohort of 1676 COPD patients from 13 Asian cities. We compared the 1-year change in forced expiratory volume in one second (FEV1), modified Medical Research Council dyspnoea scale score, St George's Respiratory Questionnaire (SGRQ) score and exacerbations according to subgroup derived from cluster analysis. RESULTS: Factor analysis revealed that body mass index, Charlson comorbidity index, SGRQ total score and FEV1 were principal factors. Using these four factors, cluster analysis identified three distinct subgroups with differing disease severity and symptoms. Among the three subgroups, patients in subgroup 2 (severe disease and more symptoms) had the most frequent exacerbations, most rapid FEV1 decline and greatest decline in SGRQ total score. CONCLUSION: Three subgroups with differing severities and symptoms were identified in Asian COPD subjects.

Prospective predictors of exacerbation status in severe asthma over a 3-year follow-up.

BACKGROUND: A predisposition to exacerbations is being recognized as a distinct phenotype with "previous exacerbations" representing the strongest clinical factor associated with future exacerbation. Thus, to identify additional novel biomarkers associated with asthma exacerbations, "past exacerbation status" must be included as a confounding factor. OBJECTIVE: This study aimed to characterize the clinical and biomarker features associated with asthma exacerbations in severe asthma. METHODS: We evaluated clinical parameters from 105 severe asthmatics yearly for 3 years, as well as their exacerbation status. We classified the subjects into 3 groups: (i) consistent non-exacerbators (CNE, subjects who did not experience any exacerbation over the 3-year period); (ii) consistent frequent exacerbators (CFE, subjects with frequent exacerbation, defined as those who had 2 or more exacerbations within 1 year, throughout the 3-year period); and (iii) intermittent exacerbators (IE). We conducted multivariate analysis for comparisons among the groups for multiple factors, including several Th2-related biomarkers, in addition to the "past exacerbation status." RESULTS: Thirty-nine subjects were classified as CNE, 15 as CFE, and 51 as IE. Frequent exacerbations in the previous year predicted exacerbations for the following year (P < .001). Among the several Th2-related biomarkers, only FeNO was associated with exacerbation status. When we analysed the data after the second visit, the impact of FeNO on predicting future exacerbation remained significant, even after considering the exacerbation status during the first year (P < .05). CONCLUSIONS AND CLINICAL RELEVANCE: Measurement of FeNO has a significant potential to predict future asthma exacerbation, which is independent of the "past exacerbation history."

Limited reduction of ferrihydrite encrusted by goethite in freshwater sediment.

Many physical and chemical processes control the extent of Fe(III) oxyhydroxide reduction by dissimilatory Fe(III)-reducing bacteria. The surface precipitation of secondary Fe minerals on Fe(III) oxyhydroxides limits the extent of microbial Fe(III) reduction, but this phenomenon has not yet been observed in nature. This paper reports the observation of secondary Fe-mineral (goethite) encrustation on ferrihydrite surface within freshwater sediment up to 10 cm deep. The sediment surface was characterized by the predominance of ferrihydrites with biogenic stalks and sheaths. An Fe(II)-oxidizing bacterium (Gallionellaceae) was detected by 16S rRNA gene analysis at sediment depths of 1 and 2 cm. Fe(2+) concentration in the sediment pore water was relatively higher at 2-4 cm depths. The 16S rRNA genes affiliated with dissimilatory Fe(III)-reducing bacteria were detected at 1, 2, and 4 cm depths. The results of the Fe K-edge extended X-ray absorption fine structure (EXAFS) analysis suggested the presence of goethite and siderite at depths below 3 cm. However, the change in the Fe-mineral composition was restricted to sediment depths between 3 and 4 cm, despite the presence of abundant ferrihydrite at depths below 4 cm. An increase in CH4 concentration was observed at deeper than 6 cm. Stable isotopic analysis of CH4 in the pore water indicated that acetoclastic CH4 occurred at depths below 7 cm. Transmission electron microscope observations suggested the presence of goethite and siderite on stalks and sheaths at depths below 3 cm. Results from conversion electron yield EXAFS analysis suggested that goethite dominated at 10 cm depth, thereby indicating that ferrihydrite was encrusted by goethite at this depth. Moreover, the incomplete reduction of ferrihydrite below depths of 4 cm was not due to the lack of organic carbon, but was possibly due to the surface encrustation of goethite on ferrihydrite.

Characterization of biogenic iron oxides collected by the newly designed liquid culture method using diffusion chambers.

We designed a new culture method for neutrophilic iron-oxidizing bacteria using liquid medium (i) to study the formation and mineralogical characteristics of biogenic iron oxides (BIOS) and (ii) to apply BIOS to various scientific and engineering applications. An iron-oxidizing bacterium, Mariprofundus ferrooxydans PV-1(T) (ATCC, BAA-1020), was cultured using a set of diffusion chambers to prepare a broad anoxic-oxic interface, upon which BIOS formation is typically observed in natural environments. Iron oxide precipitates were generated in parallel with bacterial growth. A scanning electron microscopy analysis indicated that the morphological features of the iron oxide precipitates in the medium (in vitro BIOS) were similar to those of BIOS collected from natural deep-sea hydrothermal environments in the Northwest Eifuku Seamount field in the northern Mariana Arc (in situ BIOS). Further chemical speciation of both the in vitro and in situ BIOS was examined with X-ray absorption fine structure (XAFS). A bulk XAFS analysis showed that the minerals in both BIOS were mainly ferrihydrite and oligomeric stages of amorphous iron oxyhydroxides with edge-sharing octahedral linkages. The amount of in vitro BIOS produced with the diffusion-chamber method was greater than those produced previously with other culture methods, such as gel-stabilized gradient and batch liquid culture methods. The larger yields of BIOS produced with the new culture method will allow us to clarify in the future the mineralization mechanisms during bacterial growth and to examine the physicochemical properties of BIOS, such as their adsorption to and coprecipitation with various elements and substances.

Palliative effect of lafutidine on oral burning sensation.

UNLABELLED: Lafutidine is a unique histamine H(2)-receptor antagonist (H2RA) that has a sensitizing effect on capsaicin-sensitive afferent neurons (CSAN). This effect may make lafutidine useful for the treatment of burning mouth syndrome (BMS). METHODS: To evaluate the efficacy and safety of lafutidine in patients with oral burning sensation, a randomized controlled trial was performed. Patients who had been receiving other H2RAs with no sensitizing effect on CSAN were randomly assigned to receive lafutidine 10 mg twice daily for 12 weeks, instead of the previous H2RAs, plus gargling with azulene sulfonate sodium (ASS) (lafutidine group, n = 36) or to continue to receive the previous H2RAs plus ASS gargling (control group, n = 35). The intensity of burning sensation was scored by means of a visual analog scale (VAS). RESULTS: Thirty-four patients in the lafutidine group and 30 in the control group completed the study. In the lafutidine group, the rate of improvement in the VAS score as compared with the baseline value was significant after 4, 8, and 12 weeks of treatment (P < 0.05). The improvement rate was consistently higher in the lafutidine group than in the control group; the differences between the groups were significant (P < 0.05) after 4, 8, and 12 weeks of treatment. Only two mild abdominal adverse events occurred in the lafutidine group, but neither required the termination of treatment. CONCLUSION: Oral lafutidine is very safe and effective for reducing the intensity of oral burning sensation and may therefore be a viable option for the treatment of BMS.

Relationship between improved airflow limitation and changes in airway calibre induced by inhaled anticholinergic agents in COPD.

BACKGROUND: Although airflow limitation improved by inhaled anticholinergic drugs varies among individuals with chronic obstructive pulmonary disease (COPD), the relationship between actual bronchodilation and improved pulmonary function and where in the lung such bronchodilation occurs remains unknown. A study was undertaken to determine the relationship between improved pulmonary function and changes in airway calibre at various sites in the airways in response to inhaled anticholinergic agents in patients with COPD using three-dimensional computed tomography (CT). METHODS: CT scans were performed at deep inspiration and detailed pulmonary function tests before and 1 week after daily inhalations of tiotropium bromide in 15 patients with clinically stable COPD. The airway luminal area was examined at the third (segmental) to the sixth generations of eight bronchi in the right lung. RESULTS: Bronchodilation was demonstrated by an overall average increase of 39% in the inner luminal area, and the mean (SE) forced expiratory volume in 1 s (FEV(1)) increased from 1.23 (0.11) l to 1.47 (0.13) l. The magnitude of bronchodilation was closely correlated with improved pulmonary function, particularly with that of FEV(1) (r = 0.843, p<0.001). Such correlations were significant at the fourth to the sixth generation but not at the third generation of bronchi, and the slope of the regression lines became steeper from the third to the sixth generation. CONCLUSIONS: Inhaled anticholinergic agents induce overall bronchodilation which is in proportion to improvements in FEV(1) in patients with COPD. Bronchodilation at the distal rather than the proximal airways is the determinant of functional improvement.

Effects of green tea polyphenol on methylation status of RECK gene and cancer cell invasion in oral squamous cell carcinoma cells.

RECK is a novel tumour suppressor gene that negatively regulates matrix metalloproteinases (MMPs) and inhibits tumour invasion, angiogenesis and metastasis. In the present study, we investigated the effects of epigallocatechin-3-gallate (EGCG), a major polyphenol in green tea, on the methylation status of the RECK gene and cancer invasion in oral squamous cell carcinoma cell lines. Our results showed that treatment of oral cancer cells with EGCG partially reversed the hypermethylation status of the RECK gene and significantly enhanced the expression level of RECK mRNA. Inhibition of MMP-2 and MMP-9 levels was also observed in these cells after treatment with EGCG. Interestingly, EGCG significantly suppressed cancer cell-invasive ability by decreasing the number of invasive foci (P<0.0001) as well as invasion depth (P<0.005) in three-dimensional collagen invasion model. Although further investigation is required to assess the extent of contribution of RECK on MMPs to the suppression of invasive behaviour, these results support the conclusion that EGCG plays a key role in suppressing cell invasion through multiple mechanisms, possibly by demethylation effect on MMP inhibitors such as RECK.

Functional single nucleotide polymorphisms of the CCL5 gene and nonemphysematous phenotype in COPD patients.

It was previously reported that the gain-of-function -28 guanine allele of the promoter single nucleotide polymorphism (SNP; cytosine to guanine substitution of nucleotide -28 (-28C>G)) in the CC chemokine ligand 5 gene (CCL5) was associated with susceptibility to late-onset asthma in patients who developed asthma at age > or =40 yrs. The clinical diagnosis of chronic obstructive pulmonary disease (COPD) includes emphysema and small airway disease, and upregulation of CCL5 has been described in the airways of patients with COPD. It was hypothesised that CCL5 has a genetic impact upon the variable expression of emphysema in patients with COPD. Patients with COPD were studied (n = 267). All of the patients underwent pulmonary high-resolution computed tomography (CT), and visual scoring (CT score) was performed to determine emphysema severity. Three SNPs of CCL5 were genotyped, including -403G>A, -28C>G and 375T>C. A significant difference was found in CT score according to CCL5 genotype; the -28G allele was inversely associated with CT score. When the analysis was confined to 180 patients with bronchial reversibility of <15%, even stronger evidence for this association was noted. Functional single nucleotide polymorphisms in the CC chemokine ligand 5 gene were associated with milder emphysema. Together with previous findings, the present study may identify the CC chemokine ligand 5 gene as part of a common pathway in the pathogenesis of late-onset asthma and chronic obstructive pulmonary disease with milder emphysema.

Intraoral minor salivary gland tumors: a clinicopathological study of 82 cases.

We present a retrospective study of 82 patients with intraoral minor salivary gland tumors which were diagnosed from 1979 to 2003 in Gifu University Hospital. The histological diagnoses were reevaluated according to the 1991 WHO classification. A total of 82 tumors, consisting of 55 benign and 27 malignant tumors, were found in 28 male and 54 female Japanese patients; the male-to-female ratio was 1:1.9. The mean age of the patients was 51.4+/-18.1 years. The tumors affected the palate (n = 64), the buccal region (n = 10), the upper lip (n = 6), the floor of the mouth (n = 1), and the retromolar region (n = 1). Histologically, the tumors were classified as pleomorphic adenoma (n = 54), papillary cystadenoma (n = 1), adenoid cystic carcinoma (n = 10), mucoepidermoid carcinoma (n = 8), acinic cell carcinoma (n = 3), adenocarcinoma (n = 2), basal cell adenocarcinoma (n = 1), papillary cystadenocarcinoma (n = 1), and carcinoma in pleomorphic adenoma (n = 2). From the results of the present study and review of the literature, it is suggested that the minor salivary gland tumors in Japan may be characterized by a higher incidence of benign tumors, especially of pleomorphic adenoma; a more marked tendency for female predominance; a higher incidence of palatal involvement; and a rarer occurrence of polymorphous low grade adenocarcinoma, in comparison with those reported in the literature from outside of Japan.

Upregulation of CD44 expression on bovine articular chondrocytes induced by synthetic lipid A.

Abstract The purpose of the study reported in this article was to investigate effects of synthetic lipid A on the expression of adhesion molecule CD44 on bovine articular chondrocytes. Full-thickness bovine articular cartilage was dissected from the carpometacarpal joints of 24 cows. Cartilage pieces were enzymatically digested to liberate chondrocytes. The chondrocytes were incubated in the presence of synthetic lipid A in suspension culture. Cell characteristics and binding of monoclonal antihuman CD44 antibodies were assessed with a flow cytometer. The expression of CD44 mRNA in chondrocytes was detected by reverse transcription-polymerase chain reaction (RT-PCR) technique. PCR products were quantified with a charge-coupled device image sensor. The percentage of CD44-positive chondrocytes was 42.2% ± 12.0%, 51.7% ± 6.8%, and 51.1% ± 5.0%, in the presence of lipid A at 0.25 µg/ml, 2.5 µg/ml, and 25 µg/ml, respectively, whereas it was 39.2% ± 8.9% in the absence of lipid A. In flow cytometry, two subpopulations of chondrocytes were found in each of five separate experiments, one with smaller number of forward scatter (FS) and the other with larger number of FS. The percentage of CD44-positive cells was 24.8% ± 8.5% in the subpopulation with smaller number of FS and 31.9% ± 6.4% in the subpopulation with larger number of FS at time 24 h after incubation. The bacterial component, lipid A, upregulated expression of CD44 on articular chondrocytes.

Osteosarcoma metastatic to the mandible: a case report.

A case of osteosarcoma that metastasized to the mandibular ramus from the femur in a 36-year-old man is presented. The patient was referred to us for the diagnosis and treatment of swelling of the left cheek. Radiologic examination showed a radiolucent lesion containing radiopaque areas within the left mandibular ramus. The patient previously suffered from a femoral small cell osteosarcoma, which was resected 71 months before our first examination. After induction of general anesthesia, a unilateral mandibulectomy and a simultaneous reconstruction using a titanium plate and an artificial condyle were performed. The postoperative course was uneventful, with satisfactory facial appearance and jaw function. The histopathologic features of the mandibular tumor were identical to those of the femoral tumor. Thus the mandibular lesion was diagnosed as a metastatic small cell osteosarcoma. At 27 months after the operation there had been no recurrence.

Flow-through chemiluminescence sensor using immobilized histamine oxidase from Arthrobacter crystallopoietes KAIT-B-007 and peroxidase for selective determination of histamine.

A flow sensor with immobilized oxidases is proposed for the determination of histamine in fish meat. Chemiluminometric measurement of histamine was based on the luminol reaction with hydrogen peroxide produced by immobilized histamine oxidase (EC 1.4.3.-.) and peroxidase (EC 1.11.1.7.) within a flow cell. Histamine oxidase was found in cells of Arthrobacter crystallopoietes KAIT-B-007 isolated from soil. The oxidase and peroxidase were coimmobilized covalently on tresylated hydrophilic vinyl polymer beads and packed into transparent PTFE; the tubing was used as the flow cell. One assay for histamine was done at intervals of 2 min without carryover. The calibration curve for histamine was linear from 0.1 microM to 50 microM. The response was reproducible within 1.25% of the relative standard deviation for 115-replicate injections of 50 microM histamine. The sensor system was applied to the determination of histamine in fish meat extracts.

Exhaled nitric oxide--is it really a good marker of airway inflammation in bronchial asthma?

BACKGROUND: The concentration of exhaled nitric oxide ([NO]) has been reported to reflect the inflammatory process of airways in patients with bronchial asthma, particularly when they are steroid naive. However, it is not fully understood whether it equally reflects the degree of airway inflammation in patients receiving inhaled corticosteroids, but whose symptoms are not necessarily well controlled. OBJECTIVE: To examine whether the exhaled [NO] really reflects airway inflammation in patients with bronchial asthma, regardless of treatment with inhaled steroids. METHODS: Exhaled [NO] was measured in patients with bronchial asthma (43 steroid treated and 32 steroid naive), chronic obstructive pulmonary disease (COPD) (n = 36), bronchiectasis (n = 10) and in control subjects (n = 26). We examined in each asthmatic group whether the exhaled [NO] correlated with parameters reflecting airway inflammation. RESULTS: Exhaled [NO] was significantly correlated with symptom score, clinical severity, circulating eosinophil count, and the percentage of eosinophils in induced sputum in the steroid-naive asthmatics, but not in the steroid-treated asthmatics, although airway inflammation in this group was not well controlled, as evidenced by clinical symptoms and the higher percentage of eosinophils in induced sputum. Exhaled [NO] from the patients with COPD (6.2 +/- 0. 7 ppb) or bronchiectasis (5.4 +/- 1.3 ppb) was not significantly increased compared with the controls (6.0 +/- 1.0 ppb), and was significantly lower than in the asthmatic patients as a whole (19.0 +/- 2.0 ppb). CONCLUSIONS: Although exhaled [NO] is a useful marker of airway inflammation for differential diagnosis and evaluation of severity in steroid-naive patients with bronchial asthma, it may not be as useful in steroid-treated patients.

Chemopreventive effect of dietary flavonoid morin on chemically induced rat tongue carcinogenesis.

The modifying effects of dietary exposure of the flavonoid morin on 4-nitroquinoline 1-oxide (4-NQO)-induced tongue tumorigenesis, the activities of phase II detoxifying enzymes glutathione S-transferase (GST) and quinone reductase (QR) in liver and tongue, and cell proliferation activity in tongue were investigated in male F344 rats. At 7 weeks of age, all animals except those treated with morin alone and control group were given 4-NQO (20 ppm) in drinking water for 8 weeks to induce oral neoplasms. Starting 7 days before 4-NQO exposure, experimental groups were fed experimental diets containing morin (100 and 500 ppm) for 10 weeks ("initiation feeding"). Starting 1 week after the cessation of exposure to 4-NQO, other experimental groups given 4-NQO and a basal diet were given experimental diets for 22 weeks ("post-initiation feeding"). At week 32 week, "initiation feeding" of morin caused a significant reduction in the incidence of tongue carcinoma (by 44-100%). "Post-initiation feeding" with morin also significantly decreased the frequency of tongue carcinoma (by 44%). Morin feeding elevated liver GST and QR activities and GST activity in the anterior portion of tongue. Feeding with morin significantly lowered QR activity of the posterior part of the tongue. Dietary exposure to morin significantly decreased the proliferating cell nuclear antigen-positive index in the posterior portion. Also, morin feeding lowered tongue polyamine levels, especially in the "post-initiation feeding" group. Our results indicate that morin acts as a chemopreventive agent against tongue carcinogenesis induced by 4-NQO through modification of detoxifying enzyme activities and/or cell proliferation activities.

Modifying effects of a flavonoid morin on azoxymethane-induced large bowel tumorigenesis in rats.

The modifying effect of dietary exposure to a flavonoid morin during the initiation and post-initiation phases of azoxymethane (AOM)-initiated colorectal carcinogenesis was investigated in male F344 rats. A total of 55 animals were initiated with AOM by weekly s. c. injections of 15 mg/kg body wt for 3 weeks to induce colorectal neoplasms. Rats were fed a diet containing 500 p.p.m. morin for 5 ('initiation feeding') or 28 ('post-initiation feeding') weeks. Other groups contained rats treated with morin alone (500 p.p.m. in diet) and untreated rats. At the end of the study (32 weeks), the incidence of adenocarcinoma in the large intestine of rats initiated with AOM together with (43%) or followed by (29%) a diet containing morin was smaller than that of rats given AOM alone (75%). A significant difference was found between 'post-initiation feeding' and untreated groups (P = 0.023). Although both 'initiation feeding' and 'post-initiation feeding' of morin reduced polyamine levels in colorectal mucosa and blood, 'post-initiation feeding' of morin significantly decreased the proliferating cell nuclear antigen-positive index in aberrant crypt foci. 'Post-initiation feeding' of morin significantly elevated glutathione S-transferase and quinone reductase activities in the liver and large bowel, but 'initiation feeding' caused a significant elevation of these enzymes activities only in the large bowel. These results indicate that morin could exert a weak chemopreventive effect on large bowel tumorigenesis induced by AOM when fed during the post-initiation phase.

Plasma concentration of adenosine during normoxia and moderate hypoxia in humans.

Adenosine, a purine nucleoside, plays a variety of roles in cardiovascular and ventilatory control, and may be a marker of tissue hypoxia. There is, however, no direct evidence of an increase in plasma or in tissue levels of adenosine during moderate hypoxia in humans. We measured the plasma concentrations of adenosine in an artery and the median cubital vein simultaneously in 12 normal volunteers, and also in the internal jugular vein in seven of them during normoxia and moderate hypoxia (SaO2 = 80%, 20 min) with or without dipyridamole (0.6 mg/kg) pretreatment. Dipyridamole was expected to block reuptake of adenosine by red blood cells and vascular endothelial cells so that the plasma level of adenosine would more likely reflect the tissue level. Blood was sampled with an appropriate stopping solution, and adenosine was measured with a high-pressure liquid chromatographic (HPLC)-fluorometric technique. The plasma concentration of adenosine did not rise either in the artery or in the vein at any phase of hypoxia without the dipyridamole pretreatment. However, when subjects were pretreated with dipyridamole, the plasma concentration of adenosine increased significantly and markedly in a time-dependent manner during hypoxia in the vein, but not in the artery. The adenosine level rose from 20. 7 +/- 2.5 nM (mean +/- SE) during normoxia to 50.7 +/- 10.7 nM at 20 min of hypoxia, and returned to the baseline level in the recovery phase. The plasma concentration of adenosine in the jugular vein did not change during hypoxia either with or without dipyridamole pretreatment. These data provide evidence that in humans, the local production of adenosine increases during moderate hypoxia in forearm tissue, although this is not reflected in plasma unless the subject is pretreated with dipyridamole.

Effect of anti-macrophage migration inhibitory factor antibody on lipopolysaccharide-induced pulmonary neutrophil accumulation.

Macrophage migration inhibitory factor (MIF) is a recently rediscovered pro-inflammatory cytokine that has the unique potential to override the anti-inflammatory action of glucocorticoids. Since recent reports suggest the pivotal role of MIF in acute lung injury, we examined the protective effect of anti-MIF antibody on lipopolysaccharide (LPS)-induced acute lung injury in rats. Rats were injected with LPS (7 mg/kg) intraperitoneally with or without pretreatment with anti-MIF antibody. The anti-MIF antibody significantly attenuated LPS-induced migration of neutrophils to the lungs at 4 and 24 h as demonstrated by observation of the number of neutrophils per alveolus, the activity of myeloperoxidase of the lung tissue, and cell differentiation of neutrophils in bronchoalveolar lavage (BAL) fluid. The increased level of macrophage inflammatory protein-2, a powerful neutrophil chemokine, in BAL fluid was also significantly attenuated by pretreatment with the anti-MIF antibody as compared with the control group. Additionally, positive immunostaining for MIF was observed in bronchial epithelial cells and alveolar macrophages, and Northern blot analysis of lung tissues demonstrated increased MIF mRNA 24 h after LPS injection. These data suggest that the anti-MIF antibody has therapeutic potential for the treatment of acute lung injury by suppressing the level of neutrophil chemokine in the lungs.

Citrus auraptene inhibits chemically induced colonic aberrant crypt foci in male F344 rats.

The modifying effect of dietary administration of auraptene isolated from the peel of citrus fruit (Citrus natsudaidai Hayata) on the development of azoxymethane (AOM)-induced colonic aberrant crypt foci (ACF) was investigated in rats. Male F344 rats were given s.c. injections of AOM (15 mg/kg body wt) once a week for 3 weeks to induce ACF. They also received diets containing 100 or 500 p.p.m. auraptene for 5 weeks, starting 1 week before the first dose of AOM. At termination of the study (week 5) dietary administration of auraptene caused a significant reduction in the frequency of ACF in a dose-dependent manner (P < 0.05). Feeding of auraptene suppressed expression of cell proliferation biomarkers (5-bromo-2'-deoxyuridine labeling-index, ornithine decarboxylase activity, polyamine content and number of silver stained nucleolar organizer region protein particles) in the colonic mucosa and the occurrence of micronuclei caused by AOM. Also, auraptene increased the activities of phase II enzymes (glutathione S-transferase and quinone reductase) in the liver and colon. These findings might suggest that inhibition of AOM-induced ACF may be associated, in part, with increased activity of phase II enzymes in the liver and colon and suppression of cell proliferation in the colonic mucosa.