Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 88
Filter
1.
Chemosphere ; 238: 124665, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31473529

ABSTRACT

Contaminants of emerging concern (including pharmaceuticals) are not effectively removed by municipal wastewater treatment plants (WWTPs), so particular concern is related to agricultural wastewater reuse due to their possible uptake in crops irrigated with WWTPs effluents. Advanced oxidation processes (AOPs) and solar AOPs have been demonstrated to effectively remove pharmaceuticals from different aqueous matrices. In this study, an heterogeneous photocatalytic process using powdered nitrogen-doped TiO2 immobilized on polystyrene spheres (sunlight/N-TiO2) was compared to the benchmark homogenous AOP sunlight/H2O2 in a compound triangular collector reactor, to evaluate the degradation of three pharmaceuticals (carbamazepine (CBZ), diclofenac (DCF), trimethoprim (TMP)) in water. The degradation of the contaminants by sunlight and sunlight-AOPs well fit the pseudo-first order kinetic model (but for TMP under sunlight). High removal efficiency by solar photolysis was observed for DCF (up to 100%, half-life sunlight cumulative energy QS,1/2 = 2 kJ L-1, half-life time t1/2 = 32 min), while CBZ (32%, QS,1/2 = 28 kJ L-1, t1/2 = 385 min) and TMP (5% removal after 300 min) removal was poor. The degradation rate of CBZ, TMP and DCF was found to be slower during sunlight/H2O2 (QS,1/2 = 5 kJ L-1, t1/2 = 77 min; QS,1/2 = 20 kJ L-1, t1/2 = 128 min; QS,1/2 = 4 kJ L-1, t1/2 = 27 min, respectively) compared to sunlight/N-TiO2 (QS,1/2 = 4 kJ L-1, t1/2 = 55 min; QS,1/2 = 3 kJ L-1, t1/2 = 42 min; QS,1/2 = 2 kJ L-1, t1/2 = 25 min, respectively). These results are promising in terms of solar technology upscale because the faster degradation kinetics observed for sunlight/N-TiO2 process would result in smaller treatment volume, thus possibly perspective compensating the cost of the photocatalyst.


Subject(s)
Carbamazepine/isolation & purification , Diclofenac/isolation & purification , Photolysis , Sunlight , Trimethoprim/isolation & purification , Kinetics , Nitrogen , Oxidation-Reduction , Photolysis/drug effects , Photolysis/radiation effects , Titanium , Wastewater/chemistry , Water Pollutants, Chemical/isolation & purification , Water Purification/methods
2.
J Colloid Interface Sci ; 537: 671-681, 2019 Mar 01.
Article in English | MEDLINE | ID: mdl-30481729

ABSTRACT

In this paper, the photocatalytic degradation of organic pollutants was investigated using Ag/ZnS nanoparticles at different noble metal loadings. The photocatalysts were prepared at room temperature by two different methods: photodeposition and chemical reduction. The obtained samples were characterized by Specific surface area measurement, X-ray photoelectron spectroscopy, X-ray Powder diffraction, ultraviolet-visible diffuse reflectance and Raman spectroscopy. The X-ray photoelectron spectroscopy spectra showed that Ag is present on ZnS surface as intermediate state between nanostructured Ag0 and Ag2O. Moreover, the addition of silver caused a significant change of the absorption spectrum of bare ZnS, resulting in higher absorbance in the visible region, due to the Ag surface plasmon band. Methylene blue (MB) was used to evaluate the photocatalytic activity of the prepared samples. The best photocatalytic activity was observed using the sample at 0.1 wt% Ag loading prepared by chemical reduction method. In particular, the almost complete MB degradation was achieved using UV-LEDs as light sources and 6 g L-1 of catalyst dosage. Finally, the optimized photocatalyst was also effective in the degradation of phenol in aqueous solution under UV irradiation.

3.
Allergol. immunopatol ; 45(1): 87-92, ene.-feb. 2017. graf, tab
Article in English | IBECS | ID: ibc-158980

ABSTRACT

BACKGROUND: Respiratory allergy is characterised by an IgE-mediated reaction. The immune system functions, including IgE production, progressively decline over time with growing up and ageing. Molecular-based allergy diagnostic defines sensitisation profile. This study aimed to evaluate the impact of age on serum allergen-specific IgE to molecular component levels in a large sample of subjects. METHODS: Serum IgE to: rCor a11, rPru p3, nJug r3, rAra h8, rGly m4, rCor a8, nPen m1, nAct d8, Bos d 8, and nGal d2 were assessed by ISAC method. Sera from 2795 patients, 1234 males (44.1%) and 1561 females (55.9%), median age 23 years (1st and 3rd quartiles: 9.7-43.7 years; age range: 1 month-103 years) were analysed. RESULTS: The number of positive tests (i.e. sensitisation) tended to increase between birth and school-age until young adulthood and then decreased. A similar age-dependent trend was observed considering the levels of each allergen components: the levels of each allergen component tended to increase until early adulthood, but Gal d 2 and Bos d 8 (rapidly diminishing), and then to decrease over time. However, the pattern is significantly dependent on each single tested food. CONCLUSIONS: Allergen-specific IgE production to food molecular components tend to reduce with ageing, but with differences between allergens. This phenomenon should be adequately evaluated managing allergic patients


No disponible


Subject(s)
Humans , Child , Adult , Respiratory Hypersensitivity/immunology , Hypersensitivity, Immediate/immunology , Food Hypersensitivity/immunology , 50293 , Allergens/immunology , Retrospective Studies
4.
Allergol Immunopathol (Madr) ; 45(1): 87-92, 2017.
Article in English | MEDLINE | ID: mdl-27720248

ABSTRACT

BACKGROUND: Respiratory allergy is characterised by an IgE-mediated reaction. The immune system functions, including IgE production, progressively decline over time with growing up and ageing. Molecular-based allergy diagnostic defines sensitisation profile. This study aimed to evaluate the impact of age on serum allergen-specific IgE to molecular component levels in a large sample of subjects. METHODS: Serum IgE to: rCor a11, rPru p3, nJug r3, rAra h8, rGly m4, rCor a8, nPen m1, nAct d8, Bos d 8, and nGal d2 were assessed by ISAC method. Sera from 2795 patients, 1234 males (44.1%) and 1561 females (55.9%), median age 23 years (1st and 3rd quartiles: 9.7-43.7 years; age range: 1 month-103 years) were analysed. RESULTS: The number of positive tests (i.e. sensitisation) tended to increase between birth and school-age until young adulthood and then decreased. A similar age-dependent trend was observed considering the levels of each allergen components: the levels of each allergen component tended to increase until early adulthood, but Gal d 2 and Bos d 8 (rapidly diminishing), and then to decrease over time. However, the pattern is significantly dependent on each single tested food. CONCLUSIONS: Allergen-specific IgE production to food molecular components tend to reduce with ageing, but with differences between allergens. This phenomenon should be adequately evaluated managing allergic patients.


Subject(s)
Age Factors , Aging/immunology , Allergens/immunology , Food Hypersensitivity/immunology , Immunoglobulin E/blood , Adolescent , Adult , Child , Female , Food , Humans , Immunization , Male , Pathology, Molecular/methods , Young Adult
5.
Pediatr Surg Int ; 28(1): 75-8, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21681581

ABSTRACT

Bronchial carcinoid tumors are the most common primary pulmonary neoplasm in the pediatric population. The widely accepted treatment for carcinoid tumors is surgical, specifically aiming at being as much as conservative on lung parenchyma, while the entire tumor is resected. A brief case is described, highlighting the importance and advantages of a surgical and endoscopic combined approach.


Subject(s)
Bronchial Neoplasms/surgery , Bronchoscopy/methods , Carcinoid Tumor/surgery , Pneumonectomy/methods , Bronchial Neoplasms/diagnosis , Carcinoid Tumor/diagnosis , Child , Diagnosis, Differential , Female , Follow-Up Studies , Humans , Intraoperative Period , Positron-Emission Tomography , Tomography, X-Ray Computed
6.
J Med Genet ; 46(4): 281-6, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19357118

ABSTRACT

BACKGROUND: Primary ciliary dyskinesia (PCD) is characterised by recurrent infections of the upper respiratory airways (nose, bronchi, and frontal sinuses) and randomisation of left-right body asymmetry. To date, PCD is mainly described with autosomal recessive inheritance and mutations have been found in five genes: the dynein arm protein subunits DNAI1, DNAH5 and DNAH11, the kinase TXNDC3, and the X-linked retinitis pigmentosa GTPase regulator RPGR. METHODS: We screened 89 unrelated individuals with PCD for mutations in the coding and splice site regions of the gene DNAH5 by denaturing high performance liquid chromatography (DHPLC) and sequencing. Patients were mainly of European origin and were recruited without any phenotypic preselection. RESULTS: We identified 18 novel (nonsense, splicing, small deletion and missense) and six previously described mutations. Interestingly, these DNAH5 mutations were mainly associated with outer + inner dyneins arm ultrastructural defects (50%). CONCLUSION: Overall, mutations on both alleles of DNAH5 were identified in 15% of our clinically heterogeneous cohort of patients. Although genetic alterations remain to be identified in most patients, DNAH5 is to date the main PCD gene.


Subject(s)
Kartagener Syndrome/genetics , Mutation , Alternative Splicing , Axonemal Dyneins , Chromatography, High Pressure Liquid/methods , Codon, Nonsense , Cohort Studies , DNA Mutational Analysis , Dyneins , Female , Gene Frequency , Genetic Predisposition to Disease , Genotype , Humans , Kartagener Syndrome/pathology , Male , Mutation, Missense , Patient Selection , Phenotype , Polymorphism, Single Nucleotide , Sequence Deletion
8.
Surg Endosc ; 19(10): 1309-14, 2005 Oct.
Article in English | MEDLINE | ID: mdl-16151683

ABSTRACT

BACKGROUND: This multicenter survey includes neonates and infants who underwent surgery for primary gastroesophageal reflux (GER) who presented with supraesophageal symptoms of unknown origin with a minimum of 12 months postoperative follow-up. METHODS: A total of 726 patients underwent GER surgery in 10 European Centers in the period 1998-2002. Respiratory symptoms were present in 204 patients (28%); 135 patients (17%) had surgery under 1 year of age, and 46 of them (6.3%) because of respiratory symptoms. Surgery was performed without any previous medical treatment in 10 cases (21%). The type of procedure included 37 complete 360 degrees wraps (80%) (Nissen, 12, and Rossetti, 25) and nine partial wraps (20%) (Thal five, Lortat Jacob one, Toupet one, others two). Gastrostomy was associated in 17 cases (37%) (6 PEG and 11 modified Stamm). No gastric emptying procedures were recorded. RESULTS: No major intraoperative complications were reported. Six patients developed complications (13%) and a redo operation was performed in three (6.5%). Respiratory outcome after antireflux surgery was good in 35 patients (76%) and fair with significantly improved respiratory symptoms in 11 (24%). CONCLUSIONS: This multicenter survey underlines that GER has to be suspected and aggressively treated in infants with difficult-to-treat supraesophageal symptoms, and also in high-risk cases, in order to prevent major complications.


Subject(s)
Gastroesophageal Reflux/surgery , Laparoscopy , Europe , Female , Gastroesophageal Reflux/complications , Humans , Infant , Male , Surveys and Questionnaires
10.
Eur J Pediatr Surg ; 14(1): 7-13, 2004 Feb.
Article in English | MEDLINE | ID: mdl-15024672

ABSTRACT

BACKGROUND/PURPOSE: The majority of gastrooesophageal reflux (GER) manifestations in children are supraoesophageal, and "spitting/posseting" is "the tip of the iceberg" because most reflux episodes are not regurgitated. Aim of the present study was to prospectively evaluate the incidence of gastrooesophageal reflux and the incidence of antireflux surgery in patients with difficult-to-treat respiratory symptoms. PATIENTS AND METHODS: Five hundred and ninety-five children with difficult-to-treat respiratory symptoms were prospectively enrolled in a blind study looking for the correlation between clinical presentation (asthma or non-asthma), oesophageal pH monitoring, X-ray barium meal, broncho-alveolar lavage, necessity for surgery, and outcome. RESULTS: pH monitoring was anomalous in 47% of patients with asthma (group A) and in 43% of those who did not have asthma as main symptom (group B). Overall, 48 patients finally underwent anti-reflux surgery (8%) as anti-reflux medical treatment did not ensure stable benefits. No major surgical complications were experienced. Postoperatively, respiratory symptoms improved strongly (Visick 1) in 69% of cases, moderately (Visick 2) in 27%, while clinical worsening (Visick 4) was observed in 4%. CONCLUSIONS: The results of this study stress the importance of symptoms, clinical response to anti-reflux medical treatment and broncho-alveolar lavage compared to classical pH parameters in the decision-making process for patients with difficult-to-treat supraoesophageal symptoms. To date no single tool alone has proved to be diagnostic in these patients. Fundoplication is recommended only when a relationship between supraoesophageal symptoms and gastrooesophageal reflux is strongly suspected.


Subject(s)
Gastroesophageal Reflux/surgery , Asthma/etiology , Case-Control Studies , Child , Child, Preschool , Female , Fundoplication , Gastroesophageal Reflux/complications , Gastroesophageal Reflux/epidemiology , Humans , Hydrogen-Ion Concentration , Incidence , Male , Monitoring, Physiologic , Prospective Studies , Respiratory Tract Diseases/etiology
11.
Surg Endosc ; 18(3): 463-5, 2004 Mar.
Article in English | MEDLINE | ID: mdl-14752641

ABSTRACT

BACKGROUND: The role of surgery is debated for children with gastroesophageal reflux disease (GERD), particularly when they show atypical symptoms. This study was designed to evaluate the safety and outcome of laparoscopic Nissen-Rossetti fundoplication performed in a selected population of children with gastroesophageal reflux and atypical supraesophageal symptoms. METHODS: This prospective study included 595 patients younger than 14 years with GERD who reported recurrent respiratory symptoms and had no benefit from standard medical treatment. Surgery was performed for 48 patients with anatomic anomalies, life-threatening events, or respiratory complications after ineffective medical treatment. The subjective and objective outcomes were evaluated. RESULTS: No major intraoperative complications were experienced, and there was no recurrence of gastroesophageal reflux during a postoperative follow-up period of 12 months. The parents' final subjective evaluation of the outcomes 12 months after surgery was positive in 44 cases and negative in 4 cases. CONCLUSIONS: Children with difficult-to-treat chronic respiratory symptoms must be evaluated for GERD, even if the need for surgery is low (8%), because complete eradication of reflux is mandatory. Radical treatment of GERD allows the pulmonologist to perform correct respiratory treatment and to prevent the development chronic and life-threatening complications.


Subject(s)
Esophageal Motility Disorders/complications , Fundoplication/methods , Gastroesophageal Reflux/surgery , Laparoscopy/methods , Adolescent , Anti-Ulcer Agents/therapeutic use , Asthma/etiology , Child , Child, Preschool , Combined Modality Therapy , Domperidone/therapeutic use , Female , Follow-Up Studies , Gastroesophageal Reflux/drug therapy , Gastroesophageal Reflux/etiology , Hernia, Hiatal/complications , Hernia, Hiatal/surgery , Humans , Hydrogen-Ion Concentration , Infant , Male , Monitoring, Physiologic , Omeprazole/therapeutic use , Prospective Studies , Recurrence , Respiration Disorders/etiology , Treatment Outcome
13.
Pediatr Pulmonol ; 34(4): 324-8, 2002 Oct.
Article in English | MEDLINE | ID: mdl-12205575

ABSTRACT

A variety of pulmonary vascular disorders, such as hemangiomatosis, telangectasia, and veno-occlusive disease, may be involved in the pathogenesis of interstitial lung diseases. We describe the case of a girl with recurrent bacterial pneumonia and progressive interstitial fibrosis affecting the right lung. Morphologic evaluation of the lung biopsy showed structural changes of the vessel walls suggesting pulmonary hypertension. The echocardiogram showed the presence of centripetal blood flow in the right pulmonary artery from the periphery of the lung to the heart. A selective right angiography demonstrated the presence of pulmonary venous obstruction at the veno-atrial junction, successfully treated by endovascular stent implantation during cardiac catheterization.


Subject(s)
Pneumonia, Bacterial/complications , Pulmonary Fibrosis/complications , Pulmonary Veins/abnormalities , Pulmonary Veno-Occlusive Disease/diagnosis , Cardiac Catheterization , Child, Preschool , Female , Humans , Pulmonary Veins/surgery , Pulmonary Veno-Occlusive Disease/surgery , Recurrence , Stents
14.
Surg Endosc ; 16(5): 750-2, 2002 May.
Article in English | MEDLINE | ID: mdl-11997815

ABSTRACT

BACKGROUND: The laparoscopic approach has become increasingly popular for fundoplication over the last few years; however many surgeons are skeptical about its real advantages. METHODS: We conducted a prospective comparative study of children operated on for gastroesophageal reflux (GER). Exclusion criteria included age <1 YEAR AND >14 years, previous surgery on the esophagus or stomach, and neurologic impairment. We compared two groups of patients who met the same inclusion/exclusion criteria. One group was treated via a laparotomic approach between January 1993 and December 1997; the other was treated via a laparoscopic approach between September 1998 and December 2000. A 360 degrees wrap was performed in each group. RESULTS: Group 1 (laparotomic approach) included 17 patients; mean operative time was 100 min and postoperative time was 7 days. Group 2 comprised 49 children operated on via a laparoscopic approach; mean operative time was 78 min and postoperative time was 48 hours. No major complications were encountered in either group. In postoperative period, two patients in group 1 had complications. One had a prolonged bout of gastroplegia, which required nasogastric drainage, and then recovered spontaneously after 20 days; the other had stenosis of the wrap, which required dilation. No relapses occurred during a follow-up of 6 months. Long-term follow-up data are not presented. Comparative analysis of the short-term functional results indicated that there were no differences between the two groups. CONCLUSION: This study confirms that the minimally invasive approach is safe and effective for the treatment of primary gastroesophageal reflux disease in children.


Subject(s)
Gastroesophageal Reflux/surgery , Laparoscopy/methods , Child , Child, Preschool , Fundoplication/methods , Humans , Prospective Studies
15.
Pediatr Pulmonol ; 30(4): 313-9, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11015132

ABSTRACT

Gastroesophageal reflux (GER) may be associated with chronic or recurrent asthma-like symptoms secondary to bronchoconstrictor reflexes and/or inhalation of gastric content. The presence of lipid-laden alveolar macrophages has been proposed as an index to establish the degree of gastric aspiration. We evaluated 20 children with "difficult to treat" respiratory symptoms and a clinical history suggestive of GER. All children underwent 24-hr esophageal pH monitoring (pHm) and fiberoptic bronchoscopy with bronchoalveolar lavage (BAL). The amount of lipid per single macrophage was determined by a semiquantitative method, using fluorescence microscopy to detect Nile-Red-stained BAL cells and calculating a lipid-laden macrophage index (LLMI). Eleven children had positive pHm recordings, suggesting the presence of GER (pH-positive patients), and 9 had negative pHm records (pH-negative patients). The pH-positive patients had higher percentages of neutrophils and higher LLMI than the pH-negative children (P < 0.05). There were no correlations between the pHm records and either % BAL neutrophils or LLMI in pH-positive or pH-negative patients (P > 0.05; each correlation). In contrast, a single correlation was found between % BAL neuytrophils and LLMI, both in the pH-positive and in the pH-negative patients (r = 0.72, P = 0.02 and r = 0.71, P = 0.04, respectively). These data demonstrate that a significant proportion of pH-positive patients with respiratory symptoms have BAL abnormalities that suggest airway inflammation and gastric content aspiration. However, the intensity of GER as indicated by pH monitoring does not correspond with BAL data in all patients.


Subject(s)
Bronchoalveolar Lavage , Esophagus/chemistry , Gastroesophageal Reflux/diagnosis , Respiratory Tract Diseases/diagnosis , Bronchoscopy , Child , Humans , Hydrogen-Ion Concentration , Macrophages, Alveolar , Sensitivity and Specificity , Severity of Illness Index
17.
Int J Pediatr Otorhinolaryngol ; 50(1): 23-30, 1999 Oct 15.
Article in English | MEDLINE | ID: mdl-10596883

ABSTRACT

Sinusitis is a common complication of non-allergic and allergic rhinitis, and can trigger lower respiratory diseases, such as bronchitis and asthma. Standard radiography is unable to give any data about the underlying pathological mechanisms (infectious or allergic) involved and infectious rhinosinusitis is very common in pediatric age, even in allergic patients. We investigated the possibility of obtaining more useful diagnostic information, performing nasal brushing (NB) on 117 children with recurrent respiratory symptoms. The following hypothesis were evaluated: (1) whether NB neutrophil/eosinophil percentages and/or NB culture could predict the radiological evidence of maxillary sinusitis; and (2) whether differences between nonallergic and allergic patients could be detected. In the total patient group and in the nonallergic group, the comparison of NB neutrophil percentages in patients with and without maxillary sinusitis showed a statistically significant difference (median 2 and 18%, respectively; P < 0.001). In the nonallergic group, a NB neutrophil rate > or = 5% was chosen as a cut-off between positive and negative NB diagnosis of rhinosinusitis and NB data were compared with radiological investigations. The results obtained showed that NB was fairly sensitive (91%) and predictive (84%). In allergic patients, neither neutrophil nor eosinophil percentages significantly correlated with the presence of sinusitis. Microbiological studies showed that, even if the presence of bacteria in NB resulted associated with sinusitis, a negative culture was not predictive of the absence of the disease. We therefore suggest that NB describes the present inflammatory status of the upper airways, hence, it is more suitable to describe the inflammation related to ongoing upper respiratory tract infections rather than chronic inflammation due to allergic rhinitis, characterized by relapsing episodes of acute inflammation. In conclusion, we propose to consider NB a reliable tool in the diagnosis of rhinosinusitis, particularly in nonallergic pediatric patients. Compared to standard radiological techniques, NB makes it possible to avoid radiation exposure and gives information about the pathological mechanisms involved in the single patient.


Subject(s)
Nasal Lavage Fluid/immunology , Nasal Mucosa/immunology , Rhinitis, Allergic, Perennial/immunology , Adolescent , Child , Child, Preschool , Chronic Disease , Eosinophils/immunology , Female , Humans , Immunoglobulin E/immunology , Inflammation , Male , Maxillary Sinusitis/diagnosis , Maxillary Sinusitis/diagnostic imaging , Maxillary Sinusitis/immunology , Neutrophils/immunology , Paranasal Sinuses/diagnostic imaging , Retrospective Studies , Sensitivity and Specificity , Tomography, X-Ray Computed
18.
Ann Allergy Asthma Immunol ; 83(1): 49-54, 1999 Jul.
Article in English | MEDLINE | ID: mdl-10437816

ABSTRACT

OBJECTIVE: To test in vitro and in vivo the hypothesis that sodium nedocromil could modulate the expression of surface molecules on airway epithelial cells. METHODS: Human bronchial epithelial cells, obtained from surgically resected bronchi, were cultured and stimulated with recombinant IFN-gamma in the presence of sodium nedocromil. The intensity of the expression of surface molecules HLA-DR and ICAM-1 molecules on bronchial epithelial cells in vitro, was quantified by specific antibody staining and flow-cytometry analysis. Furthermore, we studied the effect of the drug on airway inflammation in vivo and on allergic rhinitis patients sensitized to house dust mites. Nasal epithelial cells were collected by brushing, at baseline and 2 to 3 weeks after treatment with sodium nedocromil. The expression of HLA-DR and ICAM-1 molecules was measured by flow-cytometry, and the proportions of neutrophils and eosinophils "contaminating" the epithelial cells evaluated by light microscopy examination of nasal brushings. RESULTS: The enhanced HLA-DR and ICAM-1 expression, induced by IFN-gamma, was effectively downregulated, in a dose-dependent manner, by sodium nedocromil. At all the concentrations tested (10(-9) to 10(-4) M), the inhibitory activity of the drug was stronger on HLA-DR than on ICAM-1 expression (P<.05, all comparisons). As compared with healthy subjects, patients with allergic rhinitis had a higher expression of HLA-DR (P<.05) but not of ICAM-1 molecules (P>.05) on nasal epithelial cells, and higher proportions of nasal eosinophils (P<.05). Treatment with sodium nedocromil downregulated the expression of HLA-DR (P<.05), but not of ICAM-1 (P>.05), and induced a mild, but not statistically significant, decrease of nasal eosinophilia (P>.05). CONCLUSION: These data demonstrate that the antiinflammatory activity of sodium nedocromil may include modulation of surface molecule expression on airway epithelial cells.


Subject(s)
Bronchi/cytology , Epithelial Cells/metabolism , HLA-DR Antigens/biosynthesis , Intercellular Adhesion Molecule-1/biosynthesis , Nedocromil/pharmacology , Adolescent , Anti-Allergic Agents/therapeutic use , Cell Communication/drug effects , Cells, Cultured , Child , Down-Regulation/drug effects , Female , Humans , Hypersensitivity, Immediate/drug therapy , Hypersensitivity, Immediate/pathology , Interferon-gamma/pharmacology , Male , Middle Aged , Nasal Mucosa/immunology , Nedocromil/therapeutic use
19.
Br J Pharmacol ; 125(6): 1382-6, 1998 Nov.
Article in English | MEDLINE | ID: mdl-9863671

ABSTRACT

Chromones (sodium cromoglycate and sodium nedocromil) block cell swelling-activated Cl- channels in NIH-3T3 fibroblasts and endothelial cells. This has led to hypothesize that cell volume regulation might be involved in asthma pathogenesis. Using whole-cell patch-clamp experiments, we studied the effect of chromones on volume-sensitive Cl- currents in transformed human tracheal epithelial cells (9HTEo-) and in primary cultures of human bronchial epithelial cells (BE). Cl- currents activated by hypotonic shock were poorly blocked by extracellular nedocromil or cromoglycate. The block was voltage-dependent since it was observed only at positive membrane potentials. At the concentration of 5 mM, the current inhibition by both chromones at +80 mV was about 40% for 9HTEo- and only 20% for BE. Intracellular application of chromones elicited a voltage-independent inhibition in 9HTEo- cells. Under this condition, volume-sensitive Cl- currents were reduced at all membrane potentials (60 and 45% inhibition by 2 mM nedocromil and cromoglycate respectively). In contrast intracellular chromones were ineffective in BE cells. The relative refractoriness to chromones, in contrast with the high sensitivity shown by other Cl- channels, suggests that the epithelial volume-sensitive Cl- channel is not involved in asthma.


Subject(s)
Anti-Asthmatic Agents/pharmacology , Chloride Channels/antagonists & inhibitors , Chlorides/physiology , Cromolyn Sodium/pharmacology , Nedocromil/pharmacology , Trachea/drug effects , 3T3 Cells/drug effects , 3T3 Cells/physiology , Animals , Cells, Cultured , Chloride Channels/physiology , Epithelial Cells/drug effects , Epithelial Cells/physiology , Humans , Kinetics , Membrane Potentials/drug effects , Membrane Potentials/physiology , Mice , Sensitivity and Specificity , Trachea/physiology
20.
Am J Physiol ; 275(5): L917-23, 1998 11.
Article in English | MEDLINE | ID: mdl-9815109

ABSTRACT

We performed Ussing chamber experiments on cultured human bronchial epithelial cells to look for the presence of electrogenic dibasic amino acid transport. Apical but not basolateral L-arginine (10-1, 000 microM) increased the short-circuit current. Maximal effect and EC50 were approximately 3.5 microA/cm2 and 80 microM, respectively, in cells from normal subjects and cystic fibrosis patients. The involvement of nitric oxide was ruled out because a nitric oxide synthase inhibitor (NG-nitro-L-arginine methyl ester) did not decrease the arginine-dependent current. Apical L-lysine, L-alanine, and L-proline, but not aspartic acid, were also effective in increasing the short-circuit current, with EC50 values ranging from 26 to 971 microM. Experiments performed with radiolabeled arginine demonstrated the presence of an Na+-dependent concentrative transporter on the apical membrane of bronchial cells. This transporter could be important in vivo to maintain a low amino acid concentration in the fluid covering the airway surface.


Subject(s)
Amino Acids/pharmacology , Bronchi/physiology , Carrier Proteins/metabolism , Cell Membrane/physiology , Epithelial Cells/physiology , Alanine/pharmacology , Amiloride/pharmacology , Amino Acid Transport Systems , Arginine/pharmacology , Cell Membrane/drug effects , Cells, Cultured , Epithelial Cells/drug effects , Humans , Kinetics , Lysine/pharmacology , Membrane Potentials/drug effects , Membrane Potentials/physiology , Nitric Oxide Donors/pharmacology , Penicillamine/analogs & derivatives , Penicillamine/pharmacology , Proline/pharmacology , S-Nitroso-N-Acetylpenicillamine
SELECTION OF CITATIONS
SEARCH DETAIL
...