ABSTRACT
BACKGROUND: COPD is a complex, heterogeneous disease characterised by progressive development of airflow limitation. Spirometry provides little information about key aspects of pathology and is poorly related to clinical outcome, so other tools are required to investigate the disease. We sought to explore the relationships between quantitative CT analysis with functional, inflammatory and infective assessments of disease to identify the utility of imaging to stratify disease to better predict outcomes and disease response. METHODS: Patients from the AERIS study with moderate-very severe COPD underwent HRCT, with image analysis determining the quantity of emphysema (%LAA<- 950), small airways disease (E/I MLD) and bronchial wall thickening (Pi10). At enrolment subjects underwent lung function testing, six-minute walk testing (6MWT), blood sampling for inflammatory markers and sputum sampling for white cell differential and microbiological culture and PCR. RESULTS: 122 subjects were included in this analysis. Emphysema and small airways disease had independent associations with airflow obstruction (ß = - 0.34, p < 0.001 and ß = - 0.56, p < 0.001). %LAA<- 950 had independent associations with gas transfer (ß = - 0.37, p < 0.001) and E/I MLD with RV/TLC (ß = 0.30, p =0.003). The distance walked during the 6MWT was not associated with CT parameters, but exertional desaturation was independently associated with emphysema (ß = 0.73, p < 0.001). Pi10 did not show any independent associations with lung function or functional parameters. No CT parameters had any associations with sputum inflammatory cells. Greater emphysema was associated with lower levels of systemic inflammation (CRP ß = - 0.34, p < 0.001 and fibrinogen ß = - 0.28, p =0.003). There was no significant difference in any of the CT parameters between subjects where potentially pathogenic bacteria were detected in sputum and those where it was not. CONCLUSIONS: This study provides further validation for the use of quantitative CT measures of emphysema and small airways disease in COPD as they showed strong associations with pulmonary physiology and functional status. In contrast to this quantitative CT measures showed few convincing associations with biological measures of disease, suggesting it is not an effective tool at measuring disease activity.
Subject(s)
Bronchi/diagnostic imaging , Pulmonary Disease, Chronic Obstructive/diagnostic imaging , Pulmonary Emphysema/diagnostic imaging , Respiratory Tract Infections/diagnostic imaging , Tomography, X-Ray Computed , Aged , Aged, 80 and over , Bronchi/physiopathology , Female , Forced Expiratory Volume/physiology , Humans , Inflammation/diagnostic imaging , Inflammation/physiopathology , Male , Middle Aged , Pulmonary Disease, Chronic Obstructive/physiopathology , Pulmonary Emphysema/physiopathology , Respiratory Tract Infections/physiopathology , Tomography, X-Ray Computed/methodsABSTRACT
Administration of 0.4% clofibrate in the diet stimulated estradiol (E(2))-induced mammary carcinogenesis in the August-Copenhagen Irish (ACI) rat without having an effect on serum levels of E(2). This treatment stimulated by several-fold the NAD(P)H-dependent oxidative metabolism of E(2) and oleyl-CoA-dependent esterification of E(2) to 17beta-oleyl-estradiol by liver microsomes. Glucuronidation of E(2) by microsomal glucuronosyltransferase was increased moderately. In contrast, the activity of NAD(P)H quinone reductase 1 (NQO1), a representative monofunctional phase 2 enzyme, was significantly decreased in liver cytosol of rats fed clofibrate. Decreases in hepatic NQO1 in livers of animals fed clofibrate were noted before the appearance of mammary tumors. E(2) was delivered in cholesterol pellets implanted in 7-8-week-old female ACI rats. The animals received AIN-76A diet containing 0.4% clofibrate for 6, 12 or 28 weeks. Control animals received AIN-76A diet. Dietary clofibrate increased the number and size of palpable mammary tumors but did not alter the histopathology of the E(2)-induced mammary adenocarcinomas. Collectively, these results suggest that the stimulatory effect of clofibrate on hepatic esterification of E(2) with fatty acids coupled with the inhibition of protective phase 2 enzymes, may in part, enhance E(2)-dependent mammary carcinogenesis in the ACI rat model.
Subject(s)
Clofibrate/toxicity , Estradiol/agonists , Hypolipidemic Agents/toxicity , Mammary Neoplasms, Animal/chemically induced , Microsomes, Liver/drug effects , Animals , Clofibrate/administration & dosage , Diet , Estradiol/blood , Estradiol/metabolism , Female , Hypolipidemic Agents/administration & dosage , Mammary Neoplasms, Animal/pathology , Microsomes, Liver/enzymology , NAD(P)H Dehydrogenase (Quinone)/metabolism , Rats , Rats, Inbred ACIABSTRACT
RATIONALE: Basic science research suggests a causal role for endothelial dysfunction in chronic obstructive pulmonary disease (COPD). Clinical studies examining endothelial function are lacking, particularly early in the disease. Flow-mediated dilation (FMD) is a physiologic measure of endothelial reactivity to endogenous nitric oxide. OBJECTIVES: We hypothesized that lower FMD among former smokers would be associated with lower post-bronchodilator FEV(1), higher percentage of emphysema using computed tomography (CT) and lower diffusing capacity. METHODS: We measured FMD, pulmonary function, and CT percentage of emphysema in a random sample of 107 cotinine-confirmed former smokers in the ongoing EMCAP study. FMD was defined as percentage change in the brachial artery diameter with reactive hyperemia. Generalized additive models were used to adjust for potential confounders and assess linearity. MEASUREMENTS AND MAIN RESULTS: Mean age of participants was 71 +/- 5 years, 46% were female, and pack-years averaged 48 +/- 26. Mean FMD was 3.8 +/- 3.1%; mean post-bronchodilator FEV(1), 2.3 +/- 0.8 L; and mean CT percentage of emphysema, 26 +/- 10%. A 1 SD decrease in FMD was associated with a 132-ml (95% confidence interval, 16-248 ml; P = 0.03) decrement in post-bronchodilator FEV(1) and a 2.6% (95% confidence interval, 0.5-4.7%; P = 0.02) increase in CT percentage of emphysema in fully adjusted models. These associations were linear across the spectrum from normality to disease, independent of smoking history, and also significant among participants without COPD. Associations with diffusing capacity were consistent but nonsignificant (P = 0.09). The FMD-FEV(1) association was entirely attributable to percentage of emphysema. CONCLUSIONS: Impaired endothelial function, as measured by FMD, was associated with lower FEV(1) and higher CT percentage of emphysema in former smokers early in COPD.
Subject(s)
Blood Flow Velocity/physiology , Brachial Artery/physiopathology , Cardiovascular Diseases/physiopathology , Endothelium, Vascular/physiopathology , Pulmonary Emphysema/physiopathology , Aged , Cardiovascular Diseases/complications , Cohort Studies , Female , Forced Expiratory Volume/physiology , Humans , Male , Pulmonary Emphysema/etiology , Pulmonary Emphysema/pathology , Pulsatile Flow/physiology , Respiratory Physiological Phenomena , Smoking/adverse effects , Vasodilation/physiologyABSTRACT
BACKGROUND: Handheld spirometers have several advantages over desktop spirometers, but worries persist regarding reproducibility and validity of data from handheld spirometers. We undertook an independent examination of the EasyOne handheld spirometer. METHODS: The laboratory testing included reproducibility and validity testing with a waveform generator. We used standard American Thoracic Society waveforms for in-line testing, calibration adaptor testing, and testing during compression of the mouthpiece. The clinical testing involved repeated tests with 24 spirometry-naïve volunteers and comparison to spirometry results from laboratory (volume-sensing dry rolling seal) spirometer. RESULTS: The EasyOne exceeded standard thresholds for acceptability with the American Thoracic Society waveforms. In-line testing yielded valid results from the EasyOne. Between the EasyOne and the reference spirometer readings the mean +/- SD difference was 0.03 +/- 0.23 L for forced vital capacity (FVC) and -0.06 +/- 0.09 L for forced expiratory volume in the first second (FEV(1)). The calibration adaptor showed no appreciable problems. Extreme compression of the mouthpiece reduced the measured values. In clinical testing the coefficients of variation and limits of agreement were, respectively, 3.3% and 0.24 L for FVC, 2.6% and 0.18 L for FEV(1), and 1.9% and 0.05 for the FEV(1)/FVC ratio. The EasyOne readings were lower than those from the reference spirometer; the differences were: -0.12 L for FVC, -0.17 L for FEV(1), and -0.02 for FEV(1)/FVC. The limits of agreement were within criteria for FVC but not for the FEV(1), possibly due to a training effect. CONCLUSION: The EasyOne spirometer yielded generally reproducible results that were generally valid, compared to the values from the laboratory spirometer. The use of the EasyOne in clinical, occupational, and research settings seems justified.
Subject(s)
Spirometry/instrumentation , Technology Assessment, Biomedical/methods , Adult , Female , Forced Expiratory Flow Rates , Humans , Male , Middle Aged , Reproducibility of Results , Respiratory Insufficiency/diagnosis , Spirometry/standardsABSTRACT
The freeze-dried aqueous extract (AE) from the aerial parts of Scoparia dulcis was tested for its effects on experimental gastric hypersecretion and ulcer in rodents. Administration of AE to animals with 4h pylorus ligature potently reduced the gastric secretion with ED(50)s of 195 mg/kg (rats) and 306 mg/kg (mice). The AE also inhibited the histamine- or bethanechol-stimulated gastric secretion in pylorus-ligated mice with similar potency suggesting inhibition of the proton pump. Bio-guided purification of the AE yielded a flavonoid-rich fraction (BuF), with a specific activity 4-8 times higher than the AE in the pylorus ligature model. BuF also inhibited the hydrolysis of ATP by H(+),K(+)-ATPase with an IC(50) of 500 microg/ml, indicating that the inhibition of gastric acid secretion of Scoparia dulcis is related to the inhibition of the proton pump. Furthermore, the AE inhibited the establishment of acute gastric lesions induced in rats by indomethacin (ED(50)=313 mg/kg, p.o.) and ethanol (ED(50)=490 mg/kg, p.o.). No influence of the AE on gastrointestinal transit allowed discarding a possible CNS or a cholinergic interaction in the inhibition of gastric secretion by the AE. Collectively, the present data pharmacologically validates the popular use of Scoparia dulcis in gastric disturbances.
Subject(s)
Gastric Acid/metabolism , Gastric Mucosa/drug effects , Plant Extracts/pharmacology , Scoparia/chemistry , Water/chemistry , Animals , Anti-Ulcer Agents/pharmacology , Crosses, Genetic , Drug Evaluation, Preclinical , Female , Gastric Acidity Determination , Gastric Mucosa/metabolism , Ligation , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Phytotherapy , Pylorus/surgery , Rats , Rats, Wistar , Stomach/drug effectsABSTRACT
Maytenus ilicifolia Mart. ex. Reissek (Celastraceae), a medicinal plant known in Brazil as "espinheira-santa" is commonly used to treat gastric disorders. The effect of the flavonoid-rich fraction separated from the leaves was evaluated for its gastroprotective properties and the mechanism(s) involved in this activity. Intraperitoneal administration of the flavonoid-rich fraction potently protected rats from experimentally induced chronic (ED(50)=79 mg/kg) and acute gastric lesions by ethanol (ED(50)=25mg/kg) and indomethacin (ED(50)=4 mg/kg) without altering the decreased amount of cytoprotective glutathione and mucus amount in the injured gastric mucosa. A potent reduction of gastric acid hypersecretion (ED(50)=7 mg/kg, i.p.) was accompanied by a reduction of nitric oxide release (ED(50)=1.6 mg/kg, i.p.) in the gastric secretion of 2h pylorus ligated rats which suggests an important role for nitric oxide-dependent mechanisms. Inhibition of gastric acid secretion in vivo was correlated with the in vitro inhibition of rabbit gastric H(+),K(+)-ATPase activity (IC(50)=41 microg/mL). Chemical investigation of the fraction showed galactitol (25%), epicatechin (3.1%) and catechin (2%) as the majoritary components. Collectively, the results show that the flavonoid-rich fraction of Maytenus ilicifolia potently protects animals from gastric lesions with high potency through inhibition of gastric acid secretion.
Subject(s)
Flavonoids/therapeutic use , Gastric Mucosa/drug effects , Maytenus/chemistry , Protective Agents/therapeutic use , Proton Pump Inhibitors , Stomach Ulcer/drug therapy , Acetic Acid , Animals , Female , Gastric Acid/metabolism , Gastric Juice/chemistry , Gastric Mucosa/metabolism , Glutathione/metabolism , Indomethacin , Mucus/metabolism , Nitrates/metabolism , Nitric Oxide/metabolism , Nitrites/metabolism , Plant Leaves/chemistry , Rats , Rats, Wistar , Stomach Ulcer/chemically induced , Stomach Ulcer/metabolismABSTRACT
Activities of Phase II antioxidant enzymes, including NAD(P)H:quinone oxidoreductase 1 (NQO1), glutathione S-transferase (GST), UDP-glucuronosyltransferase (UGT), and phenol sulfotransferase 1A1 (SULT1A1) were measured in brain of August-Copenhagen Irish (ACI) rats exposed chronically to low doses of estradiol (E(2)). ACI rats were selected for study because this strain is highly responsive to treatment with low doses of E(2) as indexed by a high incidence of E(2)-induced mammary tumors compared to other strains. Rats were exposed chronically to 3 mg E(2) contained in cholesterol pellets implanted subcutaneously for 6 weeks. This treatment increased activities of all four enzymes in the striatum of male but not female ACI rats. Blood E(2) levels at time of sacrifice correlated closely with activities of striatal NQO1, GST, and SULT1A1, but not with striatal UGT. NQO1, GST, and SULT1A1 activities in other brain regions including the cortex, cerebellum, and hippocampus were less sensitive to chronic E(2) treatment. NQO1 was primarily localized in vascular elements and neurons and SULT1A1 primarily in neurons and neuropil of control and E(2)-treated rats. Collectively, these results suggest that enhanced expression of NQO1, GST, and SULT1A1 may contribute to the antioxidant effects of E(2) in the striatum, an area of the brain that may be particularly prone to oxidative stress because of its high content of catecholamines.
Subject(s)
Arylsulfotransferase/metabolism , Brain/drug effects , Estradiol/administration & dosage , Glucuronosyltransferase/metabolism , Glutathione Transferase/metabolism , NAD(P)H Dehydrogenase (Quinone)/metabolism , Animals , Blotting, Western/methods , Brain/enzymology , Drug Administration Schedule , Estradiol/blood , Female , Immunohistochemistry/methods , Male , Radioimmunoassay/methods , Rats , Rats, Inbred ACI , Sex FactorsABSTRACT
Achillea millefolium L. (Asteraceae), popularly known as yarrow, has been used in folk medicine to treat complaints such as inflammation, pain, wounds, hemorrhages and gastrointestinal disturbances. The aim of the present study was to assess the safety and efficacy of the aqueous extract (AE) of the plant after chronic exposure. Indeed, the AE was effective in protecting the gastric mucosa against acute gastric lesions induced by ethanol and indomethacin and in healing chronic gastric lesions induced by acetic acid with (ED(50)=32 mg/kg, p.o.). Safety studies were performed in female and male Wistar rats treated daily with AE (0.3-1.2 g/kg, p.o./day) or vehicle (water, 10 ml/kg/day) for 28 or 90 consecutive days. Satellite groups consisted of animals sacrificed 30 days after the end of these treatments. Clinical observations, body and organ weight measurements, gross autopsy, hematology, clinical biochemical and histopathological examinations were performed. Slight changes in liver weight, cholesterol, HDL-cholesterol and glucose were observed in male and female animals. These changes were not correlated with dose or time of exposure of the animals to the AE. Overall, the results show the antiulcer potential of the aerial parts of the Achillea millefolium which is accompanied by no signs of relevant toxicity even at very long chronic exposure.
Subject(s)
Achillea/chemistry , Anti-Ulcer Agents , Stomach Ulcer/drug therapy , Administration, Oral , Animals , Anti-Ulcer Agents/adverse effects , Anti-Ulcer Agents/pharmacology , Anti-Ulcer Agents/therapeutic use , Blood Cell Count , Blood Coagulation/drug effects , Body Weight/drug effects , Female , Male , Organ Size/drug effects , Plant Extracts/adverse effects , Plant Extracts/pharmacology , Plant Extracts/therapeutic use , Rats , Rats, Wistar , Time FactorsABSTRACT
Medicinal plants are commonly used in Latin American folk medicine for the treatment of gastric problems. In order to understand the properties of some of their chemical constituents, four natural xanthones, an acetylated derivative, two coumarins (mammea A/BA and mammea C/OA) isolated from Calophyllum brasiliense Cambess and two flavonoids (minimiflorin and mundulin) isolated from Lonchocarpus oaxacensis Pittier, and the chalcone lonchocarpin isolated from Lonchocarpus guatemalensis Benth were tested for their activities on gastric H+,K+-ATPase isolated from dog stomach. All the compounds tested inhibited H+,K+-ATPase activity with varied potency. The xanthones inhibited the H+,K+-ATPase with IC50 values ranging from 47 microM to 1.6 mM. Coumarins inhibited H+,K+-ATPase with IC50 values of 110 and 638 microM. IC50 values for the flavonoids ranged from 9.6 to 510 microM among which minimiflorin was the most potent. The results suggest that H+,K+-ATPase is sensitive to inhibition by several types of structurally different natural compounds. The potency of the effects on gastric H+,K+-ATPase depends on the presence, position and number of hydroxyls groups in the molecule. Collectively, these results suggest a potential for important pharmacological and toxicological interactions by these types of natural products at the level of H+,K+-ATPase which may explain, at least in part, the gastroprotective properties, indicated by traditional medicine, of the plants from which these compounds were isolated.
Subject(s)
Coumarins/pharmacology , Enzyme Inhibitors/pharmacology , Flavonoids/pharmacology , Plants, Medicinal/chemistry , Proton Pump Inhibitors , Stomach/enzymology , Xanthones/pharmacology , Animals , Calophyllum/chemistry , Coumarins/isolation & purification , Derris/chemistry , Dogs , Enzyme Inhibitors/isolation & purification , Female , Flavonoids/isolation & purification , Xanthones/isolation & purificationABSTRACT
We determined the effects of subchronic exposure to aqueous extract of leaves from Achillea millefolium (AE) on enzyme- and non-enzyme-dependent antioxidant systems in rats. Seven days treatment with AE (1 g/kg/twice a day, p.o.) altered the reduced glutathione (GSH) levels and antioxidant enzyme activities in several organs of the animals. Amount of GSH in uterus was increased (73%) while in kidneys it was decreased (23%). Besides, NAD(P)H quinone oxidoreductase 1 (NQO1) activity was increased in forestomach (26%) and in liver (64%), while glutathione S-transferase activity was decreased in the forestomach (32%) and increased in the liver (41%), kidney (35%) and uterus (37%). In preliminary experiments targeting the interaction of AE with acetaminophen (600 mg/kg, p.o.), we observed augmentation of acetaminophen-induced increase of the plasmatic alanine aminotransaminase, aspartate aminotransaminase and lactate dehydrogenase. Overall, the results indicate a potential toxic interaction of AE compounds with xenobiotics that use the glutathione pathway.
Subject(s)
Achillea/chemistry , Antioxidants/metabolism , Plant Extracts/pharmacology , Acetaminophen/toxicity , Analgesics, Non-Narcotic/toxicity , Animals , Female , Glutathione/metabolism , Kidney/enzymology , Kidney/metabolism , Liver/drug effects , Liver/enzymology , Male , Mice , Plant Extracts/toxicity , Plant Leaves/chemistry , Rats , Reactive Oxygen Species/metabolism , Uterus/metabolismABSTRACT
Himatanthus lancifolius, popularly known as "agoniada" in Brazil, is largely used in folk medicine against asthma, dysmenorrhea and as an emenagogue and abortive. This study reveals the effects of an alkaloid rich fraction (AlkF) obtained from the bark of Himatanthus lancifolius in vascular and non-vascular smooth muscle responsiveness. Incubation of AlkF (3-30 microg/ml) during 15 min generates a concentration-related and fully reversible reduction in maximal contractile responses evoked by acetylcholine and phenylephrine in rat jejune and aorta preparations, respectively. Exposition of endothelium-denuded pre-contracted rat aorta rings to AlkF results in a complete relaxation, with EC(50) of 22.2 (16.2-28.2 microg/ml). AlkF is also able to induce a concentration-related rightward shift of cumulative concentration curves for calcium in uterus and aorta rings maintained in depolarizing nutritive solution. Moreover, addition of AlkF in calcium-free solution also reduces, in a concentration-dependent manner, the ability of caffeine and phenylephrine to contract aorta rings. This study reveals that the bark of Himatanthus lancifolius possesses one or more indole alkaloids able to alter non-vascular and vascular smooth muscle responsiveness, an event that may involve the blocking of calcium entry or changes on intracellular calcium utilization or mobilization.
Subject(s)
Alkaloids/pharmacology , Apocynaceae/chemistry , Muscle, Smooth/drug effects , Acetylcholine/antagonists & inhibitors , Acetylcholine/pharmacology , Alkaloids/chemistry , Animals , Aorta, Thoracic/drug effects , Calcium/physiology , Calcium Chloride/pharmacology , Chromatography, High Pressure Liquid , Female , Ileum/drug effects , In Vitro Techniques , Male , Muscle Contraction/drug effects , Muscle Tonus/drug effects , Muscle, Smooth, Vascular/drug effects , Phenylephrine/pharmacology , Plant Bark/chemistry , Rats , Rats, Wistar , Uterine Contraction/drug effects , Vas Deferens/drug effects , Vasoconstrictor Agents/pharmacology , Vasodilator Agents/antagonists & inhibitors , Vasodilator Agents/pharmacologyABSTRACT
Estradiol (E2) has been linked to both, protection against damage associated with chronic diseases or exposure to chemicals, and to the incidence of cancer. In its protective role, E2 appears to attenuate oxidative stress while as a carcinogen, E2 damages macromolecules via formation of reactive catechol metabolites. Alterations in the expression of antioxidant and xenobiotic metabolizing enzymes upon administration of pharmacological doses of E2 have been previously identified, but the effect of chronic exposure to low concentrations of E2 on activities of those enzymes in liver is unclear. The August-Copenhagen Irish (ACI) rat is more sensitive to estrogen-induced carcinogenesis than the Sprague-Dawley rat. Accordingly, the effect of treatment of female ACI and Sprague-Dawley rats for 6 weeks with E2 on activities of NAD(P)H quinone oxidoreductase 1 (NQO1), glutathione peroxidase, glutathione S-transferase (GST), phenol sulfotransferase (SULT1A1), cytochrome P450 (CYP450) and UDP-glucuronosyltransferase (UGT) was studied. Basal expression of these enzymes was similar in livers from both strains prior to exposure to E2. However, only NQO1 and GST activity was increased (3- and 2.5-fold, respectively) in liver cytosol of ACI rats treated with E2. In contrast, only NQO1 activity was increased modestly in livers of Sprague-Dawley rats. Other enzymes were not significantly affected in the livers of ACI or Sprague-Dawley rats following chronic treatment with E2. The selective induction of NQO1 and GST activity suggests that under physiological conditions, E2 may protect against oxidative stress via elevation of these antioxidant enzymes. The marked induction of NQO1 and GST in the ACI rat indicates a potential for this strain to be used as a model to study the E2-mediated modulation of these enzymes in tissues that are either sensitive to E2 carcinogenesis or to its protective effects.
Subject(s)
Estradiol/pharmacology , Glutathione Transferase/biosynthesis , Liver/enzymology , Quinone Reductases/biosynthesis , Animals , Arylsulfotransferase/metabolism , Cytochrome P-450 Enzyme System/metabolism , Cytosol/metabolism , Enzyme Induction/drug effects , Estradiol/analogs & derivatives , Estradiol/metabolism , Female , Glucuronides/metabolism , Glutathione Peroxidase/metabolism , Glutathione Transferase/metabolism , Immunoblotting , Liver/drug effects , Microsomes, Liver/enzymology , Microsomes, Liver/metabolism , Oxidation-Reduction , Quinone Reductases/metabolism , Rats , Rats, Inbred ACI , Rats, Sprague-Dawley , Time FactorsABSTRACT
Excess production of H2O2 has been implicated in oncogenesis. The object of the present study was twofold: first, to determine the influence of chronic estradiol (E2) on the activities of selected hepatic antioxidant enzymes in female ACI rats, a strain that is highly sensitive to the induction of estrogen dependent mammary tumors; secondly, to evaluate the actions of dietary clofibrate, a peroxisome proliferator, on activities of these enzymes in control and E2-treated ACI rats. Enzymes selected for study were: NAD(P)H quinone oxidoreductase (NQO1), glutathione S-transferase (GST) and glutathione peroxidase (GPx). Cytosolic catalase (CAT) was also measured as an index of peroxisome proferation in control and E2- treated animals. E2 was administered chronically over 6 and 12 week periods from cholesterol pellet implants containing either 1 or 3 mg E2. Animals were fed AIN-76A diets with or without 0.4% clofibrate over the experimental period. NQO1 and GST but not GPx were induced to varying degrees (NQO1 about 300%, and GST about 45-97%) by chronic E2-treatment. E2-induced increases in these activities were completely prevented in rats exposed to dietary clofibrate. Dietary clofibrate also caused slight but significant reductions in baseline activities of NQO1, GST and GPx in control animals. Serum E2 levels, increased approximately 540% in a dose-dependent manner, and were not altered by dietary clofibrate. It is concluded that chronic E2 treatment markedly induces several important hepatic antioxidant enzymes in female ACI rats, and induction of these activities by E2 is inhibited completely by dietary clofibrate. Both of these actions have the potential to markedly influence the profile of E2 metabolites exported from the liver to E2 sensitive extrahepatic tissues and influence the initiation and progression of hormone-dependent tumors.
Subject(s)
Anticholesteremic Agents/pharmacology , Antioxidants/pharmacology , Clofibrate/pharmacology , Enzyme Inhibitors/pharmacology , Estradiol/pharmacology , Liver/enzymology , Animals , Catalase/antagonists & inhibitors , Catalase/metabolism , Diet , Electron Transport Complex I/antagonists & inhibitors , Electron Transport Complex I/metabolism , Enzyme Inhibitors/blood , Estradiol/blood , Female , Glutathione Peroxidase/antagonists & inhibitors , Glutathione Peroxidase/metabolism , Glutathione Transferase/antagonists & inhibitors , Glutathione Transferase/metabolism , Liver/drug effects , Rats , Rats, Inbred StrainsABSTRACT
Characteristics of acyl-coenzyme A (acyl-CoA):steroid acyltransferase from the digestive gland of the oyster Crassostrea virginica were determined by using estradiol (E2) and dehydroepiandrosterone (DHEA) as substrates. The apparent Km and Vmax values for esterification of E2 with the six fatty acid acyl-CoAs tested (C20:4, C18:2, C18:1, C16:1, C18:0, and C16:0) were in the range of 9-17 microM E2 and 35-74 pmol/min/mg protein, respectively. Kinetic parameters for esterification of DHEA (Km: 45-120 microM; Vmax: 30-182 pmol/min/mg protein) showed a lower affinity of the enzyme for this steroid. Formation of endogenous fatty acid esters of steroids by microsomes of digestive gland and gonads incubated in the presence of ATP and CoA was assessed, and at least seven E2 fatty acid esters and five DHEA fatty acid esters were observed. Some peaks eluted at the same retention times as palmitoleoyl-, linoleoyl-, oleoyl/palmitoyl-, and stearoyl-E2; and palmitoleoyl-, oleoyl/palmitoyl-, and stearoyl-DHEA. The same endogenous esters, although in different proportions, were produced by gonadal microsomes. The kinetic parameters for both E2 (Km: 10 microM; Vmax: 38 pmol/min/mg protein) and DHEA (Km: 61 microM; Vmax: 60 pmol/min/mg protein) were similar to those obtained in the digestive gland. Kinetic parameters obtained are similar to those observed in mammals; thus, fatty acid esterification of sex steroids appears to be a well-conserved conjugation pathway during evolution.
Subject(s)
Esterification , Ostreidae/metabolism , Steroids/metabolism , Acyltransferases/metabolism , Animals , Chromatography, High Pressure Liquid , Dehydroepiandrosterone/metabolism , Estradiol/metabolism , Fatty Acids/metabolism , Kinetics , Microsomes , Ostreidae/chemistry , VertebratesABSTRACT
The esterification of two model vertebrate steroid hormones - estradiol (E2) and dehidroepiandrosterone (DHEA) - was studied in the oyster Crassostrea virginica. The activity of acyl-CoA:steroid acyltransferase was characterized in microsomal fractions isolated from oyster digestive glands. The apparent Km and Vmax values changed with the fatty acid acyl-CoA used (C20:4, C18:2, C18:1, C16:1, C18:0 or C16:0), and were in the range of 9-17 microM, and 35-74 pmol/min/mg protein for E2, and in the range of 45-120 microM, and 30-182 pmol/min/mg protein for DHEA. Kinetic parameters were also assessed in gonadal tissue. The enzyme saturated at similar concentrations, although conjugation rates were lower than in digestive gland. Preliminary data shows that tributyltin (TBT) in the low microM range (1-50) strongly inhibits E2 and DHEA esterification, the esterification of E2 being more sensitive to inhibition than that of DHEA. Overall, results indicate that apolar conjugation occurs in oysters, in both digestive gland and gonads, at a very similar rate to mammals, suggesting that this is a well conserved conjugation pathway during evolution. Esterification, together with other mechanisms, can modulate endogenous steroid levels in C. virginica, and might be a target for endocrine disrupters, such as TBT.
Subject(s)
Coenzyme A-Transferases/antagonists & inhibitors , Dehydroepiandrosterone/metabolism , Estradiol/metabolism , Ostreidae/metabolism , Trialkyltin Compounds/toxicity , Animals , Coenzyme A-Transferases/metabolism , Dose-Response Relationship, Drug , Esters , Gonads/metabolism , Kinetics , Microsomes/metabolismABSTRACT
INTRODUCTION: The aetiology of acute exacerbations of chronic obstructive pulmonary disease (COPD) remains incompletely understood and strategies for treatment and prevention have not altered significantly for many years. Improved understanding of the role of respiratory pathogens in acute exacerbations of COPD (AECOPD) is required and the use of molecular microbiological techniques may lead to insights into host-pathogen interactions and the development of more targeted therapeutic approaches. METHODS AND ANALYSES: Acute Exacerbation and Respiratory InfectionS in COPD (AERIS) is a longitudinal epidemiological study to assess how changes in the COPD airway microbiome contribute to the incidence and severity of AECOPD. Patients with COPD aged 40-85 are followed monthly for 2 years, and reviewed within 72 h of onset of symptoms of AECOPD. Exacerbations are detected using daily electronic diary cards. Blood, sputum, nasopharyngeal and urine samples are collected at prespecified timepoints. Molecular diagnostic and typing techniques are used to describe the dynamics of airway infection during AECOPD and stable disease, and associations with clinical outcome. This study aims to refine the case definition of AECOPD to reflect the possible microbiological aetiology. AERIS will assess the impact of AECOPD on health-related quality of life and healthcare resource utilisation, and the possible interactions between nutritional status, infection and immune responses. ETHICS AND DISSEMINATION: AERIS is conducted in accordance with the Declaration of Helsinki and Good Clinical Practice, and has been approved by the institutional ethics and review board. All participants must provide written informed consent. The results obtained will be disseminated at international medical conferences and in peer-reviewed publications. DISCUSSION: Few other studies have addressed the complexity of the microbiological and systemic components of COPD or employed real-time electronic tracking of symptoms to identify AECOPD and potential aetiological triggers. RESULTS: Results of AERIS will increase our understanding of the contribution of pathogens to AECOPD, potentially leading to new targeted therapeutic and preventative interventions. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT01360398.
Subject(s)
Pulmonary Disease, Chronic Obstructive/microbiology , Respiratory Tract Infections/diagnosis , Adult , Aged , Aged, 80 and over , Clinical Protocols , Disease Progression , Female , Health Services/statistics & numerical data , Humans , Longitudinal Studies , Male , Microbiological Techniques , Middle Aged , Molecular Diagnostic Techniques , Nutritional Status , Prospective Studies , Quality of Life , Research Design , United KingdomABSTRACT
BACKGROUND: Emphysema on CT is common in older smokers. We hypothesised that emphysema on CT predicts acute episodes of care for chronic lower respiratory disease among older smokers. MATERIALS AND METHODS: Participants in a lung cancer screening study age ≥ 60 years were recruited into a prospective cohort study in 2001-02. Two radiologists independently visually assessed the severity of emphysema as absent, mild, moderate or severe. Percent emphysema was defined as the proportion of voxels ≤ -910 Hounsfield Units. Participants completed a median of 5 visits over a median of 6 years of follow-up. The primary outcome was hospitalization, emergency room or urgent office visit for chronic lower respiratory disease. Spirometry was performed following ATS/ERS guidelines. Airflow obstruction was defined as FEV1/FVC ratio <0.70 and FEV1<80% predicted. RESULTS: Of 521 participants, 4% had moderate or severe emphysema, which was associated with acute episodes of care (rate ratio 1.89; 95% CI: 1.01-3.52) adjusting for age, sex and race/ethnicity, as was percent emphysema, with similar associations for hospitalisation. Emphysema on visual assessment also predicted incident airflow obstruction (HR 5.14; 95% CI 2.19-21.1). CONCLUSION: Visually assessed emphysema and percent emphysema on CT predicted acute episodes of care for chronic lower respiratory disease, with the former predicting incident airflow obstruction among older smokers.
Subject(s)
Airway Obstruction/diagnosis , Hospitalization/statistics & numerical data , Lung Neoplasms/diagnosis , Pulmonary Disease, Chronic Obstructive/diagnosis , Pulmonary Emphysema/complications , Smoking/adverse effects , Acute Disease , Aged , Aged, 80 and over , Airway Obstruction/etiology , Early Detection of Cancer , Female , Follow-Up Studies , Forced Expiratory Volume , Humans , Lung Neoplasms/etiology , Male , Middle Aged , Prospective Studies , Pulmonary Disease, Chronic Obstructive/etiology , Respiratory Function Tests , Tomography, X-Ray Computed , Vital CapacityABSTRACT
ETHNOPHARMACOLOGICAL RELEVANCE: Maytenus ilicifolia Mart. ex. Reissek (Celastraceae) is widely used in Brazilian folk medicine to treat gastric disturbances. AIM OF THE STUDY: This work intended to characterize the effects of Maytenus ilicifolia on gastrointestinal motility. MATERIALS AND METHODS: Gastric emptying and intestinal transit were measured in the same animal. Mice received a semisolid marked with phenol red, half an hour after treatment with extracts. The amount of marker in the stomach and the distance reached in the intestine after 15 min were measured as index of gastrointestinal emptying and intestinal transit, respectively. RESULTS: Intraperitoneal administration of a flavonoid-rich extract potently reduced the gastric emptying (ED(50)=89 mg/kg) and the intestinal transit (ED(50)=31 mg/kg) of mice. Bio-guided purification of the flavonoid-rich extract by chemical partition with solvents of decreasing polarity yielded fraction insF with about 12-14 times higher activity than the initial flavonoid extract in both the gastric emptying and the intestinal transit. The inhibitory effects of the insF (9.7 mg/kg, i.p.) on gastric emptying and intestinal transit were reversed by co-administration of bethanechol (10 mg/kg, s.c.) but not by co-administration of metoclopramide (30 mg/kg, p.o.) indicating muscarinic but not dopaminergic interaction of the compounds of Maytenus. Chemical investigation of the insF fraction by HPLC-MS allowed the identification of 4 free flavonoids (catechin, epicatechin, quercetin and kaempferol), 29 flavonol glycosides and 8 tannins. The flavonol glycosides ranged from 1 to 4 monosaccharide units, having mainly quercetin and kaempferol as aglycone moieties, and the tannins were composed by catechin/epicatechin and/or afzelechin/epiafzelechin. CONCLUSIONS: Overall, the results indicate that the components of Maytenus ilicifolia have a potential use in the treatment of gastrointestinal motility disturbances such as diarrhea.
Subject(s)
Cholinergic Agents/pharmacology , Gastric Emptying/drug effects , Gastrointestinal Motility/drug effects , Maytenus , Plant Extracts/pharmacology , Animals , Bethanechol/pharmacology , Cholinergic Agents/administration & dosage , Cholinergic Agents/chemistry , Female , Flavonoids/pharmacology , Flavonols/pharmacology , Glycosides/pharmacology , Injections, Intraperitoneal , Maytenus/chemistry , Mice , Plant Extracts/administration & dosage , Plant Extracts/chemistry , Plant Extracts/isolation & purification , Plants, Medicinal , Tannins/pharmacologyABSTRACT
Cigarette smoking is a major source of oxidative stress. Protein carbonyls have been used as a biomarker of oxidative stress because of the relative stability of carbonylated proteins and the high protein concentration in blood. Increased levels of carbonyl groups have been found in serum proteins of smokers compared to nonsmokers. However, neither the dose effect of current cigarette smoke nor other predictors of oxidative stress have been studied. Hence, we used an Enzyme-Linked Immunosorbent Assay (ELISA) to evaluate plasma protein carbonyls in smokers recruited in the Early Lung Cancer Action Project (ELCAP) program. The lung cancer screening program enrolled current and former smokers age 60 years and over without a prior cancer diagnosis. A total of 542 participants (282 men and 260 women) completed a baseline questionnaire and provided blood samples for the biomarker study. Protein oxidation was measured by derivatization of the carbonyl groups with 2,4-dinitrophenylhydrazine (DNPH) and ELISA quantitation of the DNPH group. Current smoking status was confirmed with urinary cotinine. The mean (+/-S.D.) protein carbonyl level was 17.9+/-2.9 nmol carbonyl/ml plasma. Protein carbonyls did not differ significantly by gender. Carbonyl levels were higher among current than former smokers, but these differences did not attain statistical significance, nor did differences by urine cotinine levels, pack-years, pack/day among current smokers, and smoking duration. In a multiple regression analysis, higher protein carbonyl levels were independently associated with increasing age (0.59 nmol/ml increase per 10 years, 95% CI 0.14, 1.05, p=0.01), African-American vs. white race/ethnicity, (1.30 nmol/ml, 95% CI 0.4, 2.19, p=0.008), and lower educational attainment (0.75 nmol/ml, 95% CI 0.12, 1.38, p=0.02). Although we found no significant difference between current vs. past cigarette smoking and protein carbonyls in this older group of smokers, associations were found for age, ethnicity, and educational attainment. Our results indicate that the measurement of plasma carbonyls by this ELISA technique is still an easy and suitable method for studies of diseases related to oxidative stress.
Subject(s)
Lung Neoplasms/prevention & control , Oxidative Stress , Protein Carbonylation/physiology , Smoking/blood , Aged , Biomarkers/blood , Enzyme-Linked Immunosorbent Assay , Female , Humans , Hydrazines/blood , Lung Neoplasms/blood , Lung Neoplasms/epidemiology , Lung Neoplasms/etiology , Male , Mass Screening , Middle Aged , New York City/epidemiology , Surveys and QuestionnairesABSTRACT
Oxidative stress and inflammation are hallmarks of chronic obstructive pulmonary disease (COPD). A critical byproduct of oxidative damage is the introduction of carbonyl groups into amino acid residues. We hypothesize that plasma carbonyl content is inversely correlated with lung function and computed tomography (CT) measures of lung density among smokers and is elevated in COPD. Carbonyl was measured in plasma of participants aged 60 years and older by ELISA. Generalized linear and additive models were used to adjust for potential confounders. Among 541 participants (52% male, mean age 67 years, 41% current smokers), mean plasma carbonyl content was 17.9+/-2.9 nmol ml(-1) and mean forced expiratory volume in one second (FEV(1)) was 80.7+/-20.9% of predicted. Plasma carbonyl content was inversely associated with FEV(1), but this relationship was largely explained by age. Multivariate analyses ruled out clinically meaningful associations of plasma carbonyl content with FEV(1), FEV(1)/FVC (forced vital capacity) ratio, severity of airflow obstruction, and CT lung density. Plasma carbonyl content is a poor biomarker of oxidative stress in COPD and emphysema.