Endogenous nitric oxide in patients with stable COPD: correlates with severity of disease.
(17/2097)
BACKGROUND: Increased levels of exhaled nitric oxide (eNO) have been reported in asthmatic subjects but little information is available on eNO in patients with advanced chronic obstructive pulmonary disease (COPD). A study was undertaken to evaluate the levels of eNO in patients with stable COPD of different degrees of severity. METHODS: Peak and plateau values of eNO (PNO and PLNO, respectively) were evaluated in 53 patients with COPD and analysed according to the level of forced expiratory volume in one second (FEV1) and the presence of cor pulmonale (CP) (group 1, FEV1 < 35% predicted with CP, n = 15; group 2, FEV1 < 35% predicted without CP, n = 15; group 3, FEV1 > 35% predicted, n = 23). Seventeen normal subjects served as controls. RESULTS: All the patients with COPD had reduced levels of PLNO compared with the controls (mean (SD) 6.3 (3.0) and 9.4 (2.8) ppb, respectively). In groups 1 and 2 PLNO levels were significantly lower than in subjects in group 3 (5.5 (2.9), 5.7 (3.5), and 7.1 (2.7) ppb, respectively; p < 0.01 ANOVA). In all subjects % predicted FEV1 correlated slightly with PLNO but not with PNO. CONCLUSION: Patients with severe stable COPD have reduced levels of eNO compared with normal subjects. eNO levels are slightly related to the severity of airflow obstruction. (+info)
Increase in exhaled nitric oxide levels in patients with difficult asthma and correlation with symptoms and disease severity despite treatment with oral and inhaled corticosteroids. Asthma and Allergy Group.
(18/2097)
BACKGROUND: Patients with difficult asthma suffer chronic moderate to severe persistent asthma symptoms despite high doses of inhaled and oral corticosteroid therapy. These patients suffer a high level of treatment and disease related morbidity but little is known about the degree of airway inflammation in these patients. METHODS: Fifty two patients were examined to assess levels of exhaled nitric oxide (NO) as a surrogate marker of inflammatory activity in this condition. From this group, 26 patients were defined with severe symptoms and current physiological evidence of reversible airway obstruction requiring high dose inhaled (> or = 2000 micrograms beclomethasone dipropionate (BDP) equivalent) or oral steroid therapy to maintain disease control. RESULTS: Exhaled NO levels were higher in subjects with difficult asthma (mean 13.9 ppb, 95% CI 9.3 to 18.5) than in normal controls (7.4 ppb, 95% CI 6.9 to 7.8; p < 0.002), but lower than levels in steroid naive mild asthmatics (36.9 ppb, 95% CI 34.6 to 39.3; p < 0.001). Prednisolone treated patients had higher exhaled NO levels than patients only requiring inhaled corticosteroids (17.5 ppb, 95% CI 11.1 to 24.0 versus 7.2 ppb, 95% CI 4.6 to 9.8; p = 0.016), suggesting greater disease severity in this group. Non-compliance with prednisolone treatment was observed in 20% of patients but this did not explain the difference between the treatment groups. Exhaled NO levels were closely correlated with symptom frequency (p = 0.03) and with rescue beta agonist use (p < 0.002), but they did not correlate with lung function. CONCLUSIONS: Exhaled NO may serve as a useful complement to lung function and symptomatology in the assessment of patients with chronic severe asthma, and in the control and rationalisation of steroid therapy in these patients. (+info)
Development of fat digestion in infancy.
(19/2097)
AIM: To measure the development of fat digestion in early life, using a stable isotope breath test. METHODS: A combined longitudinal and cross sectional study was performed on 30 term and preterm infants using 13C-labelled mixed triglyceride (MTG). Seventy six tests were performed in all. Results were expressed as cumulative percentage dose recovered over 6 hours (cPDR). RESULTS: Eighteen of 34 tests performed on infants under 30 days of age showed cPDRs below the normal range for adults and older children. The remainder of tests, performed on infants over 57 days of age, all showed cPDRs within the normal range. Peak PDR correlated significantly (r = 0. 928, p<0.01) with cPDR. CONCLUSION: The capacity to digest fat is incomplete at birth, but quickly develops to normal levels during the first months of life. The MTG breath test is a useful non-invasive method to measure the development of fat digestion in early life. (+info)
Effect of inhaled steroids on airway hyperresponsiveness, sputum eosinophils, and exhaled nitric oxide levels in patients with asthma.
(20/2097)
BACKGROUND: Airway hyperresponsiveness, induced sputum eosinophils, and exhaled nitric oxide (NO) levels have all been proposed as non-invasive markers for monitoring airway inflammation in patients with asthma. The aim of this study was to compare the changes in each of these markers following treatment with inhaled glucocorticosteroids in a single study. METHODS: In a randomised, double blind, placebo controlled, parallel study 25 patients with mild asthma (19-34 years, forced expiratory volume in one second (FEV1) >75% predicted, concentration of histamine provoking a fall in FEV1 of 20% or more (PC20) <4 mg/ml) inhaled fluticasone propionate (500 microg twice daily) for four weeks. PC20 to histamine, sputum eosinophil numbers, and exhaled NO levels were determined at weeks 0, 2, and 4, and two weeks after completing treatment. Sputum was induced by inhalation of hypertonic (4.5%) saline and eosinophil counts were expressed as percentage non-squamous cells. Exhaled NO levels (ppb) were measured by chemiluminescence. RESULTS: In the steroid treated group there was a significant increase in PC20, decrease in sputum eosinophils, and decrease in exhaled NO levels compared with baseline at weeks 2 and 4 of treatment. Subsequently, each of these variables showed significant worsening during the two week washout period compared with week 4. These changes were significantly different from those in the placebo group, except for the changes in sputum eosinophils and exhaled NO levels during the washout period. There were no significant correlations between the changes in the three markers in either group at any time. CONCLUSIONS: Treatment of asthmatic subjects with inhaled steroids for four weeks leads to improvements in airway hyperresponsiveness to histamine, eosinophil counts in induced sputum, and exhaled nitric oxide levels. The results suggest that these markers may provide different information when monitoring anti-inflammatory treatment in asthma. (+info)
Sputum eosinophils and exhaled nitric oxide during late asthmatic reaction in patients with western red cedar asthma.
(21/2097)
Examination of sputum for eosinophils and measurement of exhaled nitric oxide have been proposed as noninvasive methods of assessing airway inflammation in asthma. The use of these tests in the evaluation of patients with occupational asthma has not been reported. This study investigated the changes in sputum eosinophils and exhaled NO before and at intervals after inhalation challenge with plicatic acid in patients with suspected western red cedar asthma. Of 17 subjects who underwent challenge, nine had a positive bronchoconstrictor reaction (responders) and eight had a negative reaction (nonresponders). At 6 and 24 h after plicatic acid challenge, there was a significant increase in sputum eosinophils among responders, which was inversely related to the fall in forced expiratory volume in one second (FEV1) at 6 h. An increase in sputum eosinophils was also found in three nonresponders. Levels of exhaled NO increased at 24 h after challenge with plicatic acid in both responders and nonresponders, being significant only in nonresponders. No correlation was found between the increase in nitric oxide and the magnitude of the functional changes in the airways. There were significant correlations between the degree of sputum eosinophilia and the level of exhaled NO before and after methacholine and plicatic acid challenge. In conclusion, the late asthmatic reaction induced by plicatic acid in patients with western red cedar asthma is associated with an increase in sputum eosinophils. The usefulness of measuring sputum eosinophils and exhaled nitric oxide in the clinical evaluation of patients with suspected occupational asthma caused by low molecular weight compounds has yet to be determined. (+info)
Fructooligosaccharides and lactulose cause more symptoms in lactose maldigesters and subjects with pseudohypolactasia than in control lactose digesters.
(22/2097)
BACKGROUND: Many lactose maldigesters tolerate more lactose in experimental studies than in everyday life, in which their symptoms may result from other carbohydrates as well. OBJECTIVE: The question of whether the symptoms caused by large quantities of carbohydrates are more severe in lactose maldigesters than in control lactose digesters or in lactose digesters who report milk to be the cause of their gastrointestinal symptoms (pseudohypolactasic subjects) was studied in a randomized, double-blind, crossover study. Comparisons between commonly used diagnostic methods for lactose maldigestion were also made. DESIGN: The subjects were 40 women aged 20-63 y from 3 groups: lactose maldigesters (n = 12), pseudohypolactasic subjects (n = 15), and control lactose digesters (n = 13). The subjects were given either 50 g lactose, 50 g sucrose, 25 g lactulose, or 25 g fructooligosaccharides. After carbohydrate ingestion, urine was collected and the breath-hydrogen concentration was measured every 30 min for 3 h. Blood glucose was measured every 20 min for 1 h and subjective gastrointestinal symptoms were monitored for 8 h with a questionnaire. RESULTS: When lactulose and fructooligosaccharides were ingested, the lactose maldigesters (P = 0.04 and 0.09, respectively) and the pseudohypolactasic subjects (P = 0.006 and 0.01, respectively) reported more symptoms than did the control lactose digesters. Sucrose caused more symptoms in the lactose maldigesters than in the control lactose digesters (P = 0.05). CONCLUSIONS: Lactose maldigesters and lactose digesters with pseudohypolactasia experience more symptoms than control lactose digesters after a single intake of large amounts of indigestible carbohydrates. Lactose maldigesters also experience more symptoms after ingesting sucrose. (+info)
Effect of transgalactooligosaccharides on the composition of the human intestinal microflora and on putative risk markers for colon cancer.
(23/2097)
BACKGROUND: Nondigestible oligosaccharides have been claimed to benefit the health of the colon by selectively stimulating the growth of bifidobacteria and by decreasing the toxicity of the colon contents. OBJECTIVE: We compared the effect of 2 doses of transgalactooligosaccharides and a placebo on the composition and activity of the intestinal microflora in 18 women and 22 men. DESIGN: Strictly controlled experimental diets were supplied to 3 intervention groups in a parallel design. The study was divided into 2 consecutive 3-wk periods during which each participant consumed a run-in diet followed by an intervention diet that differed only in the amount of transgalactooligosaccharides: 0 (placebo), 7.5, and 15 g/d. Breath samples and fecal samples were collected at the end of both the run-in and intervention periods. RESULTS: Apparent fermentability of transgalactooligosaccharides was 100%. The highest dose of transgalactooligosaccharides significantly increased the concentration of breath hydrogen by 130% (P < 0.01) and the nitrogen density of the feces by 8.5% (P < 0.05). The number of bifidobacteria increased after both placebo and transgalactooligosaccharides ingestion, but the differences between these increases were not significantly different. Transgalactooligosaccharides did not significantly affect bowel habits; stool composition; the concentration of short-chain fatty acids or bile acids in fecal water; the concentration of ammonia, indoles, or skatoles in feces; fecal pH; or the composition of the intestinal microflora. CONCLUSION: We conclude that transgalactooligosaccharides are completely fermented in the human colon, but do not beneficially change the composition of the intestinal microflora, the amount of protein fermentation products in feces, or the profile of bile acids in fecal water. (+info)
Dose-dependent fate of vinyl chloride and its possible relationship to oncogenicity in rats.
(24/2097)
Studies on the fate of 14C-labeled vinyl chloride (VC) following oral administration and inhalation exposure in rats demonstrated that the disposition of VC in the body is a function of the dose. More importantly, from the data available, it appears that a correlation exists between doses of VC which cause tumors and those that saturate metabolic or detoxifying pathways. Additional studies characterized the depression of liver non-protein sulfhydryl content (primarily GSH) with the duration and concentration of exposure to VC. The results of these investigations indicate that statistical projections utilizing data collected from rats exposed to high doses of VC are invalid for predicting the hazard of low level exposure, because such projections violate a priori assumption that the dynamics governing the fate of VC in the body are unaltered. (+info)