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Biomedical subjects

A Chetta

Publications and source records attributed to A Chetta.

At least 37 records · Page 2Linked to original sources
PubMed1997

Lung epithelial permeability and bronchial responsiveness in subjects with stable asthma.

Lung epithelial permeability of asthmatic patients has been reported to be similar or lower than that of healthy subjects and to be correlated or not to bronchial hyperresponsiveness. To clarify these discrepancies, we evaluated 99mTc-DTPA pulmonary clearance in a group of carefully selected asthmatic patients with mild, stable asthma (n = 13; seven women; mean age +/- SD = 27.69 +/- 6.63 years), and compared them with a group of healthy, nonsmoking subjects (n = 8; six women; mean age +/- SD = 24.38 +/- 5.15 years). Selection criteria for asthmatics were as follows: baseline FEV1 > or = 80% of predicted values, no bronchial infections, and/or no asthma attacks during 4 weeks prior to study and peak expiratory flow rate variability lower than 20%, over a period of 3 weeks. Patients controlled symptoms with beta 2-adrenergic drugs only, regularly or on demand. Mean baseline FEV1 (+/-SD) as percent of predicted was 102.38 +/- 13.97 and 112.88 +/- 18.36, respectively (p < 0.05). In the asthmatic group, bronchial responsiveness to methacholine (PC20 M FEV1) ranged between 0.55 and 28.5 mg/mL. Mean value (+/-SD) of DTPA clearance from lungs to blood (evaluated on the first 10 min out of 30 min of the curves) in the asthmatic group was not different from that of control group (68.31 +/- 21.46 and 69.5 +/- 15.73). In the asthmatic patients, there was no correlation between PC20 M values and DTPA T1/2 min of the whole lung, nor between PC20 M and inner and outer lung clearance zones. Moreover, both in asthmatics and healthy subjects, DTPA clearance of outer (alveolar) zones was significantly faster than that of inner (bronchial) zones (57.69 +/- 19.94 vs 102.08 +/- 38.19, p < 0.001, and 59.75 +/- 12.49 vs 103.5 +/- 31.86, p < 0.003, respectively). Our data show that DTPA clearance in patients with stable asthma is similar to that found in healthy subjects; it is not correlated to degree of bronchial responsiveness and occurs more rapidly in the outer zones than in the inner zones, both in asthmatic patients and in healthy subjects. Thus, to date, DTPA clearance index is not a valid tool for identifying and/or monitoring asthmatic patients.

Adolescent↗
PubMed1996

Bronchial responsiveness to distilled water and methacholine and its relationship to inflammation and remodeling of the airways in asthma.

Although bronchial hyperresponsiveness in asthma is associated with inflammation within the airways, it is not known whether the degree and type of inflammation influence the response to different stimuli and whether pathologic changes of airway structure influence the bronchoconstrictive responses. Therefore, number of inflammatory cells in the epithelium and the lamina propria and the basement membrane thickness were estimated from bronchial biopsies taken in 27 asthmatic subjects (range percent predicted FEV1: 75.6 to 132.1, range of daily PEF variability: 1.9% to 20%) and related to the degree of bronchial responsiveness to ultrasonically nebulized distilled water (UNDW) and methacholine (M). PD20UNDW (provocative dose) was measurable in 15 of 27 patients and ranged between 1.01 and 20.4 ml. PC20M (provocative concentration) ranged between 0.15 and 31.7 mg/ml. In the 15 responders to UNDW, total inflammatory cells (p<0.04) and eosinophils (p<0.015) within the epithelium were higher than in 12 nonresponders to UNDW (PD20 > 34.8 ml). There was no correlation between PD20UNDW and any cell counts whereas negative correlations were found between PC20M and both total inflammatory cells (rs = -0.57; p<0.005) and eosinophils (rs = -0.63; p< 0.0015) within the epithelium. The degree of thickening of subepithelial layer ranged between 7 and 16 micrometers+ (n=26). Thickness correlates both with total inflammatory cells (rs = 0.49; p<0.025) and eosinophils (rs = 0.61; p< 0.003) within the epithelium. Moreover, it was correlated with baseline FEV1 (rs = -0.57; p<0.003) and daily peak expiratory flow (PEF) variability (rs = 0.51; p<0.01). A weak but significant correlation was also found between subepithelial layer thickness and PC20M (rs = -0.42; p<0.04). The results of this study demonstrate that eosinophilic inflammation of bronchial epithelium plays a role in determining UNDW and M responsiveness in asthma. Moreover, they suggest that remodeling of the airways such as thickening of subepithelial layer correlates with indices of asthma severity and could contribute to the degree of M but not to UNDW responsiveness.

Adolescent↗
PubMed1993

Histochemical characteristics and degranulation of mast cells in epithelium and lamina propria of bronchial biopsies from asthmatic and normal subjects.

We examined the staining characteristics and degranulation of mast cells in bronchial biopsy specimens taken by fiberoptic bronchoscopy from 13 stable asthmatic patients and eight normal nonsmoking subjects. Specimens were fixed in periodate-lysine-paraformaldehyde, embedded in glycol methacrylate, and stained with toluidine blue (2%) for 30 min (pH 2.7) and 7 days (pH 0.5). The number of mast cells in the epithelium and in the lamina propria was counted under light microscopy. In addition, the distribution of mast cells with different granule contents, arbitrarily defined as degranulated or partly degranulated and fully granulated, was estimated at the two levels. In asthmatic subjects, the number of mast cells in the epithelium after either staining method was significantly higher compared with that in control subjects. The number of mast cells in the lamina propria, but not in the epithelium, was significantly higher after 7 days compared with 30-min toluidine blue stain both in asthmatic (135.6/mm2 versus 74.8/mm2; p < 0.001) and control subjects (121.5/mm2 versus 71.5/mm2; p < 0.01). There was evidence of a progressive mast cell degranulation when moving toward the airway lumen in both groups. However, degranulation was more evident in asthmatic subjects. In both groups, granulated mast cells were absent in the epithelium, whereas in the lamina propria granulated mast cells were approximately one-third of total in asthmatic and two-thirds of total in normal subjects. These observations suggest that mast cells in human bronchial mucosa are heterogeneous with respect to histochemical characteristics. They provide evidence that degranulation of mast cells occurs in both asthmatic and normal subjects and that degranulation is greater in asthmatics.

Adult↗
PubMed1993

Effect of inhaled disodium cromoglycate and nedocromil sodium on propranolol-induced bronchoconstriction.

We conducted a randomized, double-blind, placebo-controlled study on the effect of disodium cromoglycate (DSCG) and nedocromil sodium (NED) on propranolol-induced bronchoconstriction (PIB) in 12 asthmatic subjects 10 to 53 years of age. Placebo (saline solution) and active drugs (10 mg) were aerosolized 30 minutes before bronchoprovocation with inhaled propranolol. Bronchial response to propranolol was expressed as the cumulative dose provoking a 20% fall in FEV1 (PD20P) and given in mumol. Reproducibility of PD20P was estimated before and after the days of study. PD20P varied within two doubling doses. Disodium cromoglycate and NED had no significant effect on baseline lung function. Although, geometric mean PD20P values (+/- GSEM) recorded after DSCG (7.24 mumol +/- 1.31) and after NED (9.22 mumol +/- 1.26) were higher than values recorded after placebo (6.55 mumol +/- 1.31), these differences were not statistically significant. A greater than 2-fold increase in PD20P was noted after NED in three subjects and in one subject after DSCG. We conclude that both DSCG and NED only modestly alter PIB, with some between subject differences.

Administration, Inhalation↗
PubMed1993

Prolonged bronchodilating effect of formoterol versus procaterol in bronchial asthma.

The tolerability and the duration of effect of 12 micrograms of formoterol and 25 micrograms of procaterol administered via metered-dose aerosol to 12 stable asthmatic patients were evaluated in a double-blind, placebo controlled trial. FEV1, pulse rate, and blood pressure were measured at baseline and every two hours after dosing for 12 hours. The bronchodilation peak was observed after two hours for both drugs. Formoterol induced a significant bronchodilating effect for 12 hours compared with both baseline and placebo values. With procaterol, significant bronchodilation occurred for six hours compared with baseline values and four hours compared with placebo. No significant changes were observed in pulse rate and blood pressure with either drug. Four subjects complained of muscle tremor after procaterol administration. We conclude that in subjects with stable asthma, inhaled formoterol at a dose of 12 micrograms maintains significant bronchodilation for 12 hours after dosing and is very well tolerated. Further studies are required to evaluate effectiveness and tolerability of high dose formoterol treatment in acute severe asthma therapy.

Adolescent↗
PubMed1993

Bronchial responsiveness to inhaled propranolol in asthmatic children and adults.

Inhaled propranolol (P) was administered to a population which included asthmatic children (30 subjects) and adults (43 subjects): 1) to investigate the determinants of induced bronchial response; 2) to examine the relationship with treatment requirements; 3) to determine the relationship with responsiveness to methacholine (M) and ultrasonically nebulized distilled water (UNDW) (50 subjects); and 4) to establish the short-term repeatability of bronchial response to propranolol compared with methacholine (22 subjects). Bronchial response to propranolol and methacholine was expressed as the cumulative provocative dose (PD20 in mumol) and responsiveness to UNDW as the provocative output (PO20 in ml.min-1) producing a 20% fall in forced expiratory volume in one second (FEV1). Response to propranolol was significantly related to the degree of responsiveness to methacholine, but not to age, gender, presence of atopy, age at asthma onset, or baseline FEV1. PD20P was measurable in all but three subjects. A significant difference in mean PD20M but not in PD20P was found between subjects requiring more anti-asthmatic treatments compared to those without therapy. The difference between geometric mean PD20P and geometric mean PD20M was 14.1. PO20UNDW was measurable in only 21 out of 50 subjects. Both PD20P and PD20M were significantly lower in responders to UNDW than in nonresponders. Reproducibility of PD20P was comparable to that of PD20M (coefficients of repeatability: 1.17 and 1.09). We conclude that bronchial responsiveness to propranolol is safely measurable in most children and adults with asthma. Repeatability of bronchial response to propranolol is comparable to that of methacholine. Moreover, responsiveness to propranolol is not a predictor of treatment requirement.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed1992

Lung function and bronchial responsiveness after bronchoalveolar lavage and bronchial biopsy performed without premedication in stable asthmatic subjects.

We evaluated tolerance, safety, and effects on lung function and bronchial responsiveness of BAL (4 x 50 ml) combined with BB (three to five specimens) performed without premedication in 13 mild and stable asthmatics and eight healthy volunteers. All subjects tolerated bronchoscopy procedures well and without serious side effects. During procedures, no supplemental oxygen was administered and no ECG abnormalities were noted. The PEFR was measured before and immediately after bronchoscopy and at 5-min intervals up until recovery. The maximal percentage fall in PEFR after bronchoscopy was significantly greater in asthmatics (23.1 +/- 13.9 percent) compared to normal subjects (7.8 +/- 8.2 percent, p less than 0.01). Changes in PEFR returned to baseline values within 120 min in all asthmatics. The tcPO2 was recorded at baseline, during and after bronchoscopy. In both groups, a significant change in tcPO2 was measured during the infusion of BAL aliquots, and persisted throughout the procedure. A significant difference in asthmatics compared to healthy subjects was evident during BB and at the end of the procedure (p less than 0.05). In asthmatics, M challenge was performed on three different days over a three-week period prior to bronchoscopy, and was repeated at intervals of 2, 6, and 24 h following procedure. The PC20 M values measured before bronchoscopy were found to have a very high reproducibility (intraclass correlation coefficient = 0.93). The PC20 values measured during experiment times after bronchoscopy were not significantly different from baseline values. These data demonstrate that in mild and stable asthmatics, BAL combined with BB can be safely performed following administration of only local anesthesia. In carefully selected asthmatic subjects, transient bronchoconstriction and a lowering of oxygen tension can be induced by BAL and BB, whereas changes in bronchial responsiveness are more unlikely to occur.

Adolescent↗
PubMed1992

Bronchial inflammation in mite-sensitive asthmatic subjects after 5 years of specific immunotherapy.

We examined the pattern and degree of the inflammatory process in bronchial biopsy specimens taken by fiberoptic bronchoscopy in eight asthmatic subjects (two women aged 19-38 years) after 5 years of specific immunotherapy (SIT) to mite extracts (SIT group). At the time of study, they received a maintenance dose of mite-extracts (last subcutaneous administration 3 weeks before bronchoscopy). Results were compared with those found in eight matched mite-sensitive subjects with stable asthma (two women aged 19-36 years; non-SIT group) and in eight healthy individuals (four women aged 22-29 years; control group). Bronchial biopsy specimens were fixed in periodate-lysine-paraformaldehyde, embedded in glycol methacrylate, and stained with hematoxylin-eosin and 2% toluidine blue. Number of eosinophils, mast cells, and total nucleated cells were counted separately in the epithelium and lamina propria by light microscopy and expressed as cells/high power field. Within the epithelium, eosinophil and mast cell counts in SIT and non-SIT groups were significantly higher compared to controls, whereas total cell counts were not statistically different. Within the lamina propria, total cell count in SIT and non-SIT groups was significantly higher compared with the control group, whereas mast cells were similar. The number of eosinophils in both SIT and non-SIT groups was higher compared with controls; however this reached statistical significance only in SIT-groups. Comparison between the two groups of asthmatics did not show any significant difference for any cell counts.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Inflammatory markers in bronchoalveolar lavage and in bronchial biopsy in asthma during remission.

Bronchoalveolar lavage and BB were performed in 13 asthmatic and six healthy subjects to characterize cellular markers of inflammation in BAL and BB; to compare cellular profile of BAL with cell infiltration in BB; to examine the relationship between bronchial responsiveness and markers of inflammation in BAL and BB. Eosinophils and mast cells were increased in BAL in asthmatic subjects; eosinophils were positively correlated with neutrophils and mast cells. Epithelial shedding was present in nine asthmatic and five control subjects. Intraepithelial cells and cells in submucosa were increased in asthmatic subjects. Eosinophils and intraepithelial mast cells were higher. Thickened basement membrane was associated with more marked cell infiltration in submucosa. Ciliated cells in BAL relate to intraepithelial cells; cells in BAL broadly reflect cell infiltration of submucosa. In the asthmatic group, the degree of bronchial responsiveness correlated with ciliated cells in BAL and with intra-epithelial cells in BB. Marked airway inflammation is associated with stable asthma; inflammatory changes within bronchial epithelium may be linked to the development of bronchial hyperresponsiveness.

Adolescent↗
PubMed1989

Therapy of asthma in adults: the control of bronchial inflammation.

Inflammatory events involve the airways in asthma. Bronchial inflammation can induce and maintain both variable airflow obstruction and bronchial hyperresponsiveness. The rationale of asthma therapy is, therefore, to use drugs which prevent and reduce the inflammation. The control of asthmatic inflammation needs specific management. Interestingly, if corticosteroids are effective, non-steroidal anti-inflammatory drugs have a negligible effect. On the other hand, sodium cromoglycate and ketotifen can act on bronchial inflammation. Moreover, in well-selected patients, immunotherapy and a strict environmental prophylaxis can play a key role in long-term therapy. In asthmatics, a careful control of inflammation can protect airways from irreversible bronchial obstruction and return bronchial hyperresponsiveness to within the range of clinical well-being.

Adrenal Cortex Hormones↗
PubMed1988

Early bronchodilating effect of a new oral beta-2-receptor agonist (broxaterol) in bronchial asthma.

In order to determine the bronchodilating activity and safety of two beta-2-receptor agonists, broxaterol and procaterol, compared with a placebo, 12 patients with reversible airway obstruction were tested in a double-blind cross-over study. The drugs were administered orally and the dosage of broxaterol was 0.5 mg, that of procaterol 0.05 mg. Measurements of forced expiratory volume in 1 s (FEV1), heart rate and blood pressure were performed before and 30, 60, 120, 240, 360, and 480 min after each treatment. Both drugs produced bronchodilation but broxaterol was statistically 30 min faster in producing this effect than procaterol (p less than 0.05). Moreover this effect for both drugs persisted significantly for up to 480 min compared with the effect of the placebo (p less than 0.005). There were no significant side effects with either drug. Heart rate and blood pressure did not show any changes in clinical significance for broxaterol or procaterol. In our study, broxaterol showed a faster bronchodilating effect than procaterol, and tolerance was the same for both drugs.

Administration, Oral↗
PubMed1988

Evaluation of bronchial responsiveness by pharmacological challenges in asthma. Inhaled propranolol in comparison with histamine and methacholine.

Bronchial challenges with bronchoconstrictive drugs have supplied important information on some relevant pathophysiological aspects of bronchial asthma, i.e. nonspecific bronchial hyperresponsiveness. Until now histamine and methacholine have been the most widely used inhalation tests. Recently, propranolol, given by inhalation, has been proposed and evaluated for possible application as a bronchial provocation challenge both in clinical and experimental setting. In asthmatic subjects with bronchial hyperresponsiveness to histamine and methacholine, inhaled propranolol induces a dose-related bronchoconstriction. In a group of 25 asthmatic patients, the mean value of provocative doses, in mumoles of propranolol that causes a 20% drop in FEV1 (PD20FEV1), is thirteen times greater than that of methacholine. In the same study, there is no correlation between the bronchial responses to the two drugs. Moreover, none of 9 normal subjects of the control group responds to inhaled propranolol. The mechanisms of propranolol-induced bronchoconstriction are poorly understood. A cholinergic reflex is probably involved, but it is likely that propranolol has some different and rather peculiar pathways. Bronchial response to inhaled propranolol is a reliable, reproducible, safe, and well-tolerated method. Bronchoconstriction induced by propranolol appears to be a very promising technique in the investigation of the mechanisms of nonspecific bronchial hyperresponsiveness.

Adolescent↗
PubMed1987

Provocative dose and dose-response curve to inhaled propranolol in asthmatic patients with bronchial hyperresponsiveness to methacholine.

This study was carried out to compare bronchial responses to inhaled propranolol (P) and methacholine (M) in a group of asthmatic subjects with mild to moderate bronchial hyperresponsiveness to M; to determine the short term reproducibility of bronchial response to propranolol; and to examine the shape of dose-response curve to P relative to that of M. Doses of M and P were given in mumoles and bronchial responses to both agents were expressed as the provocative dose that induced a 20 percent fall in FEV1 (PD20 FEV1). In 16 asthmatic patients, there was no correlation between the PD20 of the two agents. Mean PD20 M (+/- SD in log scale) was approximately nine times lower than mean PD20 P (0.64 +/- 0.96 and 5.80 +/- 1.65, respectively). This difference was statistically significant (t = 4.58, p less than 0.001). In six asthmatic patients, the reproducibility of PD20 P was similar to that of M (intraclass correlation coefficient 0.969 and 0.957, respectively). The shape of the dose-response curves to P was different from that of M in five of nine asthmatic patients when all experimental points were analyzed by double-reciprocal plot. We noticed that even small doses of inhaled P may cause a severe bronchoconstriction. Therefore, special caution should be taken to increase P doses very gradually, when studying the dose-response curve. We demonstrated that P inhalation induced a measurable bronchoconstriction in subjects with mild to moderate hyperresponsiveness and it was reproducible. However, the bronchial sensitivity to P was lower than to M. Our findings suggest that P and M have different mechanisms of action.

Asthma↗
PubMed1982

[Case of retrosternal Morgagni-Larrey hernia].

Retrosternal hernia (Morgagni-Larrey) is the less frequent of diaphragmatic defects. Nevertheless its frequency is probably more elevated than commonly believed because very often there is a lack of symptoms. The clinical case which is referred has a typical presentation but it is outlined the difficult interpretation of routine chest x-rays, while a prompt diagnostic suspicion is not always present. Surgical repair is the discussed emphasizing the very good results within a virtual absence of recurrences.

Adult↗
PubMedDate not supplied

Short-term treatment with a low dose of inhaled fluticasone propionate decreases the number of CD1a+ dendritic cells in asthmatic airways.

The activation of T-lymphocytes through the recognition of specific allergens is a crucial event in the development of allergic inflammation. Dendritic cells (DC) are potent accessory cells that play an important role in initiating bronchial immune responses by activation of T-lymphocytes. We investigated the distribution of CD1a+ DC in the bronchial biopsies from asthmatic patients, and evaluated the effects of a short course of low dose inhaled fluticasone propionate treatment. Twenty-three mild to moderate stable asthmatic patients and eight normal subjects were included in the study. Bronchoscopy with bronchial biopsies were performed in each subject. Eighteen of the 23 asthmatics underwent a second bronchoscopy after 6 weeks of low dose inhaled fluticasone propionate treatment (250 mcg bd) in a placebo-controlled double-blind study. Biopsies were embedded into glycolmethacrylate resin and analysed by immunohistochemistry methods using specific monoclonal antibodies against CD1a, which is a widely recognized marker for DC. In asthmatics, CD1a+ DC number was significantly higher in bronchial epithelium (P < 0.001) and in lamina propria (P < 0.001) when compared with normal controls. In addition, we observed that a short course of low dose inhaled fluticasone propionate treatment decreased the number of CD1a+ DC in both the bronchial epithelium (P < 0.05) and lamina propria (P < 0.01). The increased number of CD1a+ DC support the hypothesis that DC play an important role in the modulation of the immune response in chronic asthma. Short-term low dose fluticasone propionate treatment induces down-regulation of the CD1a+ DC number.

Administration, Inhalation↗